CN101865108A - Have the reciprocating pump of force transducer and be used to control the method for described reciprocating pump - Google Patents
Have the reciprocating pump of force transducer and be used to control the method for described reciprocating pump Download PDFInfo
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- CN101865108A CN101865108A CN200911000080A CN200911000080A CN101865108A CN 101865108 A CN101865108 A CN 101865108A CN 200911000080 A CN200911000080 A CN 200911000080A CN 200911000080 A CN200911000080 A CN 200911000080A CN 101865108 A CN101865108 A CN 101865108A
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B11/00—Equalisation of pulses, e.g. by use of air vessels; Counteracting cavitation
- F04B11/005—Equalisation of pulses, e.g. by use of air vessels; Counteracting cavitation using two or more pumping pistons
- F04B11/0058—Equalisation of pulses, e.g. by use of air vessels; Counteracting cavitation using two or more pumping pistons with piston speed control
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
- F04B1/02—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having two cylinders
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B11/00—Equalisation of pulses, e.g. by use of air vessels; Counteracting cavitation
- F04B11/005—Equalisation of pulses, e.g. by use of air vessels; Counteracting cavitation using two or more pumping pistons
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
- F04B49/06—Control using electricity
- F04B49/065—Control using electricity and making use of computers
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- Engineering & Computer Science (AREA)
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- General Engineering & Computer Science (AREA)
- Computer Hardware Design (AREA)
- Reciprocating Pumps (AREA)
- Control Of Positive-Displacement Pumps (AREA)
Abstract
The present invention relates to a kind of reciprocating pump that is used to produce transport flow, described transport flow is not pulsation basically, the invention particularly relates to double-piston pump; In addition, the invention still further relates to a kind of method that is used to control from area of low pressure conveying pumped medium to the reciprocating pump of high-pressure area, the pressure or the flow-sensint unit that adopt usually to be used for replacing have for this purpose wherein been used to be used to monitor the mechanical force of being carried or the measuring transducer of moment by pump structure or its associated drives unit.
Description
Technical field
The present invention relates to a kind of reciprocating pump, especially a kind of double-piston pump, it is used to produce the transport flow that does not have pulsation basically; The invention still further relates to a kind of method of described reciprocating pump that be used to control from area of low pressure conveying pumped medium to the high-pressure area.
Background technique
Reciprocating pump according to the present invention comprises: at least two piston/cylinder unit that are used for from area of low pressure conveying pumped medium to the high-pressure area, be used to drive the cam driver of at least one piston/cylinder unit, be used to control the control unit of the rotational speed of cam driver, with the sensor that is used to measure the Control Parameter actual value, wherein the actual value by described Control Parameter can obtain the degree of pulsatility of the conveyance fluid that produces in the high pressure side.
For example in liquid chromatography (liquid chromatography), especially in high pressure liquid chromatography (HPLC) (HPLC) and superhigh pressure liquid chromatography (UHPLC), adopted such pump, be used for movable phase (eluant, eluant) conveying, for example with the form of neat solvent or low voltage side gradient solvent mixture by the static phase in the splitter of correlation analysis system (package).Term " low voltage side gradient (low pressure side gradient) " is familiar with by those skilled in the art.
Relevant for the correct analysis result of quality (retention time) and quantity (peak area), need the lasting constant-quality stream (mass flow) of movable phase.Ideally, need guarantee " true mass flow " (true mass flow), also be that transport flow is constant with respect to volume in certain unit under atmospheric pressure in the time.True mass flow should by guarantee to continue at least a series of analytic processes of the connection that is relative to each other the duration.Constant mass flow has great importance, and especially in HPLC and UHPLC, this is because the discharge pressure of described pump can reach 100MPa or higher when using described analytical method.
Under such operational condition, the medium of pumping no longer shows as desirable (also promptly incompressible) liquid.This can cause such fact: because the specific compressibility of pumped medium, the discharge pressure of growth has further worsened the basic not true mass flow that is pumped medium that is produced of pulsation.
In order to reduce the pulsation in flowing of high-pressure delivery that reciprocating pump produces, a plurality of pumps with for example a plurality of pistons (especially two pistons) are operated according to conveying principle in parallel or preferably series connection.In other words, a plurality of pistons deliver into common high-pressure area, wherein relative to each other skew in time of their stroke movement, thus single transport flow superposes in theory mutually to form the not synthetic constant flow of pulsation.
Owing to have a low discharge pressure, the pulsation of total transport flow thereby can avoid fully or almost; Yet, for high or the highest discharge pressure, still can generate remaining pulsation.This remnants pulsation is caused that by the specific compression of pumped medium described specific compression is along with the increase of discharge pressure can have the effect of increase, and its degree depends on the variation physical property of pumped medium.Described remaining pulsation can begin to be reduced or suppress with the precompressed stroke by making each delivery cycle, this had guaranteed that before actual fed begins the medium in the cylinder interior space obtains compression and is positioned on high-tension side each system pressure with coupling, was used to avoid or the pumped medium short-term that reduces at least to take place when the fluid power transition from a piston to another piston refluxes and/or continues to carry and interrupts.
Known feedback control is to be used for the influence of the specific compression of (constantly) compensation pumped medium to the moment pumping efficiency in associated pump, this feedback control or be positioned at the discharge pressure in pump intake and/or outlet port based on monitoring, or based on the flow velocity of determining to be positioned at pump intake and/or outlet port (for example by according to the sensor of calorimetric measurement operate), and to the qualitative or quantitative Treatment of each measurement signal.
US4,359,312 disclose a kind of double-piston pump with cam driver, and it moves according to the in parallel of the above-mentioned type or series connection conveying principle, and discloses the method for controlling described pump based on subtractive method (subtractive approach).In order to offset the decline of pumping efficiency when increasing discharge pressure, the driving cam device that causes actual pump action comprises that lift profile (elevation profile section) is used to produce the precompressed stroke, and induction stroke correspondingly shortens with respect to angular range and quickens because of structural reason simultaneously.At first, the length of precompressed stroke is selected as follows: promptly described precompressed stroke has compensated in the maximum specific compression of appointment and has specified the influence of the specific compression of the pumped medium under the maximum permission discharge pressure to pumping efficiency,---described pump is actuated to these maximum value conditions of full remuneration.For this purpose, described equipment comprises pressure transducer, and wherein the system pressure on the high pressure side utilizes described pressure transducer to be continued to monitor.
Monitor the measured value that obtains by pressure transducer and be fed into driving control system, and the rotational speed of drive motor is modulated with following method in the precompressed stroke range: promptly by iteration and subtractive method, pump returns iteratively from the compensation of maximum value condition, thus the physical condition of the pumped medium of compensation under actual motion pressure.With its mutually concurrently, the conveying with respect to volume increases under atmospheric pressure because of the precompressed stroke that adopts respectively in feedback procedure obtains.By secondary correction factor that the cam rotational speed is superposeed, utilize modulation again to revise described unnecessary conveying.
At US4, another kind of pump and another kind of method are disclosed in 681,513.Wherein, all has independent cam driver according in two pistons of the double-piston pump of series connection conveying principle operation each.The cross section of each in two driving cam devices all has the different lift profiles (elevationprofile) that form different length of stroke features, described lift profile is according to the specific maximum delivery speed of pump and classification, and their slope has had constant value added.In each pumping circulation process, in the respective angles scope of cam, induction stroke and pump stroke and precompressed stroke are before all caused by the to-and-fro motion of driving cam, and described two transport flow are combined with the constant delivery that obtains to synthesize.
The crucial inherent defect that is used for all feedback control (described feedback control is based on the qualitative and/or quantitative Application that discharge pressure is measured) of compressibility compensation (pressure feedback), be in a series of cam rotation/pumping circulation, to carry out the in fact limited robustness (robustness) that iteration is regulated (PID control) and control when the pressure artifact takes place, because only may carry out indirectly but not directly monitoring to the displacement process of pumped medium by pressure measurement signal.Disturbance variable for example is pressure pulsation (it occurs in when sample is added in the correlation analysis system), and the especially drift of pressure measurement signal in the gradient operating process is wherein because the physical property (viscosity that changes; Temperature), and/or when the obstruction of splitter takes place maybe may take place, back pressure changes and occurs maybe may appearing at the splitter place.
Except pressure feedback method (it is used to compensate the influence of the specific compression of actual pumped medium to pumping efficiency), also known so mobile feedback method, it utilizes the flow-sensint unit be installed in liquid line on the high pressure side (and also alternatively in low voltage side) based on the monitoring to the conveying characteristic of pump, and wherein this feedback method depends on the measurement signal of described sensor.
Because pressure measurement sensor and flow-sensint unit must be suitable for for example fact of the non-constant width measuring range of 0-100MPa, and because the fact that pressure measurement sensor and flow-sensint unit must can stand high pressure and make periphery obtain sealing with acceptable effect, pressure measurement sensor and flow-sensint unit have specific technical problem.Simultaneously, they cannot influence fluid passage preferred geometrical construction aspect pressure drop and hydrokinetics, and because they directly contact with medium to be carried, they must the chemical property aspect have resistance to all media with conveying or protect away from described medium by isolating film or analog.For the situation of flow-sensint unit, especially disadvantageously, measurement signal depends on operating temperature and needs the particular thermal conductivity/ability of each medium of conveying, and therefore must carry out a plurality of parameter corrections in application facet, it can preferably utilize the substitution circulation method to be realized by circuitous calculating according to the low pressure gradient method in pump operated process, and wherein one group of reference value can assessment under true analysis operational condition.
When considering the situation of series connection double-piston pump, increased the fundamental system problem that pumping efficiency descends about the above-mentioned difficulties of design concept, this pumping efficiency descends and is caused by the harmful dead space volume in the displacement system (piston/cylinder unit) of working piston.Described volume is not discharged displacement chamber (its from the edge of closing that the edge calculates outlet valve of closing of inlet valve, or belong to above-mentioned scope) in the pump stroke process, and remains on wherein as the hydroelastic system element, because liquid has significant specific compression.Advance/go out full the answer that provides this problem in theory that is applied in of notion (all-in/all-out) entirely, and in the restriction that in fact possesses skills of the design aspect of each assembly of feasibility that belongs to the displacement chamber.
Along with discharge pressure increases, the compressibility of the medium that is transferred causes that pumping efficiency quickens to descend, and associated be that transport flow has obvious remaining pulsation more or less.This pumping efficiency only is reduced as the function that is harmful to dead space volume (this dead band volume is difficult to reduce technically), rather than as (reality) volume pumped result by compression in the displacement stroke procedure.
When adopting the low pressure gradient method to use pump, harmful dead space volume also influences the proportionality of each supply mobile (it is caused by the Proportional valve on the suction side of pump).This is because the following fact: in the process that induction stroke begins, before " fresh " liquid can flow into displacement region, described dead space volume at first had to expand into the volume under the external pressure.This causes filling the reduction of stroke efficient, and this problem is an an open question in the pump of above-mentioned prior art.
Summary of the invention
Based on above-mentioned prior art, the object of the present invention is to provide a kind of reciprocating pump and a kind of method that is used to control described pump, treat the specific compression of fed sheet of a media and to change discharge pressure even wherein change to 100MPa or may be bigger, compare known pump and method, whole pumping efficiency also can access and keep, and (remnants) of transport flow pulsation is reduced or even is inhibited.
With regard to equipment, this purpose realizes that by following a kind of reciprocating pump described reciprocating pump comprises: at least two piston/cylinder units, and its described medium transport that is used for flowing out the area of low pressure enters the high-pressure area; Driver element, it is used to drive at least one piston/cylinder unit; Control unit, it is used to control the speed that is driven of this driver element; And sensor, it is used for the actual value of acquisition controlling parameter, and the degree of pulsatility of wherein utilizing this actual value to make to produce in the high-pressure area that flows can be derived; In reciprocating pump, described sensor is suitable for being captured among the structure of at least one piston/cylinder unit and/or driver element/the place mechanical force that applies/transmit and/or the value of moment.
By the pump in accordance with the present invention design, can advantageously avoid (otherwise needs) to force working pressure or flow measurement sensor.Like this, sensor no longer must be arranged on and be pumped in the zone that medium gets wet, i.e. the high-pressure area and the zone of being got wet by medium.On the contrary, sensor can be arranged at almost any position, and only need be applicable to that monitoring is applied in and/or carries mechanical force and the moment in pump structure in pump operated process.Preferably, this sensor is provided with as follows, and promptly it is not got wet by medium that carried, is not especially got wet by the medium of precompressed or pressurized.
Basically all mechanical devices and the assembly of pump have been realized by above-mentioned pump structure.Especially, sensor monitors the power and the moment of the above-mentioned type, they the structure of the structure of piston/cylinder unit, driver element or the assembly part of the intersection of driver element and piston/cylinder unit/among carry, or be applied at Qi Chu.The driver element of the pump on the above-mentioned meaning comprises the feed drive unit.Advantageously, driver element can be a cam driver, and comprises the associated drives axle and the above-mentioned feed drive unit of strap cam dish.
The said structure of sensor produces several advantages.
Pass through said structure, be compared to the pump of conventional construction, delivered volume significantly reduces, and it is conclusive for making low pressure gradient (preferably not mixing again) through pump, and is conclusive to being suitable for providing high sample throughput (HTP) by relevant analytical system therefore.Delivered volume is defined in the volume in total fluid pipeline, and its scope is closed the joint of edge to pump discharge from the Proportional valve that forms gradient.Delivered volume is more little, and it is just few more to be used for the analyzing required time next time that analytical system is reset to initial conditions.
If sensor is not must be arranged in the zone of being got wet by medium, need not integrated transducer so, normally bidimensional rather than the desirable tubulose of described sensor, and the use condition according to them also must be chemically inert, and technical with being integrated in of fluid-tight mode under the described high pressure is complicated and expensive.In addition, aforesaid way also has favourable seondary effect: the geometrical shape of passage can be configured with following plain mode, promptly only produces direct circulating liquid zone.
And, the notion of in not being pumped the mechanical region that medium gets wet, utilizing the power measurement to monitor, provide inherently the stroke advantage of monitoring synchronously carried out in liquid displacement action, its can be in pumping circulation with the mode of function robustness realize or (even) solve.With on the contrary based on the conventional method of measuring discharge pressure and flow velocity, preceding described, may be the discharge pressure artifact that causes of the change owing to the change of pumped medium viscosity or its temperature, pressure surge when sample is supplied to the subsequent analysis system, pressure measurement signal drift and the obstruction that takes place of splitter subsequently in the low pressure gradient operating process, do not constitute disturbing factor with direct influence because handled be not the absolute value that changes but change rate.
Because the sensor by described type among the mechanical device and assembly of reciprocating pump/on the measurement of the mechanical force that is applied in/carries and/or moment replaced only providing the measurement direct measurement of discharge pressure (for example to) of indirectly measurement value, so corresponding monitor value (except that being used for pump controlled) can be evaluated to be used for further function, wherein be used for checking normal effect especially, and/or be used to check piston seal occurring wear degree at (ball) valve of liquid displacement unit.
Sensor be preferably adapted to monitoring pump structure or be embedded into or be integrated among the pump structure (it comprises driver element) and/or on tensile stress, compressive stress, shearing stress and/or the twisting stress of assembly.In principle, this sensor can be the sensor of monitoring mechanical force and/or moment, and it comprises strainometer, piezoelectric element, acoustic resonator (acoustic resonator) or optical measuring apparatus especially.
For example, can use moment or torque sensor (it is combined among the axle of driver element or cam driver or part), and monitoring moment/moment of torsion of being applied in herein or carrying.Other method is to monitor the moment of being transmitted at the driver element place of cam driver by sensor.Especially advantageously, sensor is not arranged on and is pumped the pump zone that medium is got wet on the high pressure side.Advantageously, even can also avoid sensor to be got wet by medium in low voltage side.
Preferably, reciprocating pump according to the present invention is in parallel or the series connection double-piston pump.According to advantageous particularly mode of execution as the series connection double-piston pump, piston/cylinder unit is formed the working piston unit, especially have inlet valve and outlet valve, and they also connect mutually as follows as the storage piston unit: promptly, the working piston unit extracts the medium that needs conveying from the pump area of low pressure, and be provided to described medium by a part of high-pressure area on the outlet side of pump supply and be fed to another part on the inlet side that is positioned at the storage piston unit, so that moving, the stroke by mutual adjustment obtains constant transport flow; And promptly, the storage piston unit provides whole transfer rates in the induction stroke subsequently of working piston unit.
Reciprocating pump preferably includes driver element, and it is used for each single piston/cylinder unit separately.And each driver element can drive by independent motor.This has caused the height technology degrees of freedom aspect the delivered volume of controlling and monitor each piston/cylinder unit, because can regulate two drivers mutually by the rotational speed of adjusting two motors in the limit of broad.
With regard to method, purpose of the present invention realizes by following a kind of method that is used for control piston pump (especially double-piston pump), the medium transport that described reciprocating pump is used for flowing out from the area of low pressure enters the high-pressure area, and described reciprocating pump comprises: at least two piston/cylinder units; At least one driver element, it is used for driving described piston/cylinder unit at least one; And sensor, its be used to monitor among the structure or driver element of piston/cylinder unit/on the mechanical force and/or the moment that are applied in/transmit; Described method comprises following treatment step:
I) drive at least one piston/cylinder unit with first speed (n) by driver element, so by sensor monitor among the structure and/or described driver element of described piston/cylinder unit/on the mechanical force and/or the moment that are applied in/carry,
Ii) by adopt by described sensor monitors to described mechanical force and/or the value of moment, that comes that monitoring stream goes out piston/cylinder unit is pumped the actual moment (moment) that begins to deliver into the high-pressure area of medium,
Iii) monitor at the actual compression ratio that is pumped medium when beginning to carry, especially monitor the compression ratio that is pumped medium when overvoltage or under-voltage appearance (being so-called compressibility compensation),
Iv) as follows the driver element rotational speed is modulated to second speed (n+1), that is: variation compression ratio that causes owing to the change system back pressure and/or the variation compressibility that is pumped medium that occurs in the high pressure side are compensated, and produced the pulseless basically transport flow that is pumped medium in the high-pressure area
V) by will step I in v) modulated driver element rotational speed (n+1) make all repetition methods step I of each pumping circulation as first speed (n)) to step I v).
The method according to this invention preferably makes each pumping circulation all recursively find the solution (recursively pursued).Yet control circle also can be based on the survey data of several delivery strokes.This method can produce high-pressure delivery and flow in broad discharge pressure and the constrictive scope of particular fluid, described high-pressure delivery flows and do not pulse basically.In principle, one or more piston/cylinder unit can obtain monitoring by sensor.For convenience's sake, in whole specification, only considered the situation of a piston/cylinder unit of reference.
When pumping operation at the beginning and during primer pump, also promptly after opening power after very short time, pump at first must via the start up period, until after its initial start, reaching stable transport flow.Basically, the start up period process in this actuating speed may have value arbitrarily; Yet it preferably is adjusted to the specific compression scope that pumped medium expects and is adjusted to desirable transfer rate, this with facility to pump control subsequently.
Pump reach stablize transport flow or reach the stable conveying action of pump after, begun according to practical methods of the present invention.According to this method, at least in a pumping circulation or delivery cycle process, with first speed (n) driven pump.Preferably, by sensor monitor continuously among the pump structure/on transmitted and or the mechanical force and/or the moment that apply.Especially, monitoring force and/or moment, it is transmitted and is applied among the structure of piston/cylinder unit, driver element or temporary location separately/on.According to special mode of execution, control program can be used for this purpose, and it is applicable to each chosen transfer rate.
Subsequently method step ii) in, by adopt by sensor monitors to mechanical force and/or moment determine time and piston position, wherein the actual fed that enters the high-pressure area at this time place's medium begins, be driven with first speed (n) simultaneously, perhaps at piston/cylinder unit place said circumstances take place at least by sensor monitors.The beginning of actual fed can be monitored clearly and especially preferably, especially by using the mechanical force that obtains by sensor monitors and/or the process of moment, for example obtain measured value or the measurement series value collect, for example about time or position of orientation (stroke of piston position) by mathematical method.
When with first speed (n) driven plunger/cylinder unit, along with the delivery stroke of piston advances constantly, system pressure is put aside in relevant cylinder body displacement chamber.Described pressure increases, and equals main system pressure in adjacent high-pressure area until it.When having pressure balance in the high-pressure area and in the cylinder space of piston/cylinder unit, medium is no longer carried from cylinder space.After only pressure in the cylinder space of piston/cylinder unit and the balance between the system pressure on the high pressure side were exceeded, actual conveying could take place.
Consider the mechanical force and/or the moment that are obtained by sensor monitors, the beginning to become and can discern of actual fed is because the process of power that monitors and/or torgue measurement value changes significantly.By additionally or selectively first and/or second stroke position of these values or process relevant numerical value or process deviation being assessed and are monitored, can convenient process of coming monitoring force and/or torgue measurement value by sensor.
Because the kinetic property of driver element (especially driving cam) and (separately) speed of cam driver are known, previous affected medium (in advance) compression ratio can calculate by adopting stroke position or specific driver element position (cam angle degree) by sensor monitors in piston/cylinder unit, and wherein actual fed begins when described driver element position.Especially, can determine the existence of overcompression or under-voltage contracting (mistake or under-voltage truncate are repaid).Whether in other words, can determine: the geometrical shape that presents with respect to driver element (cam driver) separately of (actual) conveying begins too early or too late, and occurred or cause (remnants) of the high-pressure flow that produces to pulse thus.Angular range be integrated in the driver element or in the cam driver to be used in particular for producing under the situation of precompressed stroke, can determine thus: at the discharge pressure separately of pumped medium and/or separately under the specific compression, by under given actuating speed, adopting the caused compression of described cam part whether too much or owe how to have compensated of the influence of the specific compression of pumped medium, and then cause the remnants of transport flow to be pulsed to pumping efficiency.When operating this pump, this feature especially has clear meaning according to low voltage side gradient method (supplying the medium of composition (composition) change on the whole in the suction side).
Before carrying beginning, affected (in advance) compression is determined, preferably finished in the mode relevant with stroke.Especially, the pulse characteristic that monitors by employing checks whether the specific compression of pumped medium has occurred crossing or undercompensation.
In the further process of this method, driver element rotational speed (perhaps cam drive speed) is modulated or be adjusted to second speed (n+1).Described second speed can be higher or lower than previous speed (n), and this depends on formerly determined actual demand precompression in the pumping circulation.As the result of this modulation, the previous too high or too low precompressed ratio of determining (crossing or undercompensation) be compensated or at least its degree diminish.The result makes, although be that system pressure on the high pressure side changes and/or the specific compression of pumped medium changes, having produced not have the transport flow of pulsing substantially.
Second speed (n+1) is applicable to the operating parameter after the change, and in the step I of next process of this method) in be used as first speed (n), and said method step iterative.Preferably, said method is finished in the stroke of piston process subsequently at each.
Based on the reference value that obtains in this way, use described method might compensate from a stroke to next stroke changing the influence of compression ratio, this compression ratio is as the change specific compression of, pumped medium caused by high pressure side variable system pressure and/or changes discharge pressure and the result that causes.
Driver element rotational speed (cam driver speed) preferably keeps constant in the initial delivery stroke procedure, more preferably keep constant in (initially) delivery stroke that starts described controlling method.Especially, in delivery stroke, mechanical force and/or moment or its process are monitored with constant drive speed.
With regard to this method, if the medium of carrying is subjected to precompression in each pumping circulation, then the method according to this invention is especially favourable.Required precompressed stroke is particularly useful for making fed sheet of a media to produce maximum delivery pressure and estimates maximum specific compression.For the maximum specific compression of expectation of at least one appointment maximum delivery pressure that will be transferred fluid and application-specific, the precompressed that is produced by described stroke is enough.Correspondingly can estimate, in process, at method step i with first speed (n) operation) in will produce overvoltage, reduce the driver element rotational speed by the modulation in the precompressed stroke procedure simultaneously.This is described to the iteration subtractive method of pumping control in other places of this specification.
According to an embodiment of the inventive method, can estimate to utilize the stroke position of (by sensor) the determined conveyor piston correction factor of deriving, wherein begin actual conveying in this position of this stroke.By this correction factor, from the working procedure of a plurality of storages, generate or select suitable working procedure, it has formed the basis to driver element rotational speed (especially in the cam portion relevant with the precompressed stroke) modulation then.
By precompressed and/or the modulation (elementary control) that causes the actuating speed of velocity of piston modulation is carried out, will take place and the previous relevant excessive conveying of selecting of specified quantity delivered (nominal delivery).Especially, the excessive conveying for (supply) volume under the external pressure will initially take place; Pump is driven and is used to compensate maximum compression and maximum operating pressure.The further embodiment according to the present invention, described excessive conveying is by being compensated on the secondary correction factor of stack (cam) drivers velocity after modulate, and this correction factor provides the compensation to excessive conveying (secondary control: produce true mass flow).
Embodiment according to the inventive method, by sensor monitors to value or value form be used to revise the loss in efficiency that is associated with induction stroke, described loss in efficiency according to the specific compression separately of pumped medium and separately discharge pressure, by the expansion of the harmful dead space volume in the compressed piston/cylinder unit displacement region in the delivery stroke process formerly, produce in the zero hour of each suction stroke; That is to say that described dead space volume will can not discharged in the delivery stroke process inevitably owing to design reasons, yet before actual fed begins, must obtain compression.Said process is preferably finished by the endurance of determining decompression phase.The part of stroke volume obtains monitoring, and wherein the described part of stroke volume can not be discharged from the displacement region of piston/cylinder unit in each pumping circulation process owing to the expansion of harmful dead space volume.The above-mentioned part of can not using of induction stroke is caused by the expansion of harmful dead space volume.Especially, in the low pressure gradient operating process, promptly when the composition of the medium that will carry change and the compressibility that changes subsequently and/or viscous effects to back pressure.This is especially favourable under very high discharge pressure, can regulate according to the degrees of expansion of harmful dead space volume because flow into the gradient composition (gradient composition) of the medium in the pump in induction stroke process subsequently.Preferably, said process realizes by opening and closing the solenoid valve that usually adopts for this purpose, and described solenoid valve is positioned at the pump intake place in the mode of suitable control and is used for each induction stroke subsequently.
Description of drawings
More advantages of the present invention and feature will become apparent from the explanation below in conjunction with the non-limiting mode of execution of accompanying drawing, wherein:
Fig. 1 represents the schematic representation of pump in accordance with the present invention, and described pump comprises the control unit that is used for (high pressure and ultrahigh pressure) liquid chromatography subtraction unit,
Fig. 2 represents such chart, and wherein the regularization stroke (normalized stroke) of working piston (last figure) and storage piston (figure below) is expressed as the function of camshaft angle of swing,
Fig. 3 represents such chart, and wherein the regularization transfer rate (normalized delivery rate) of working piston (last figure) and storage piston (figure below) is expressed as the function of camshaft angle of swing,
Fig. 4 represents such chart, and wherein the regularization power (normalized force) in working piston (last figure) and the storage piston (figure below) is expressed as the function of camshaft angle of swing,
Fig. 5 represents such chart, wherein the power at working piston place change (alteration of force) be expressed as regularization first derivative (normalized first derivative) the camshaft angle of swing function and
Fig. 6 represents such chart, and wherein inlet valve (last figure) and outlet valve (figure below) opens the function that condition table is shown the camshaft angle of swing.
Fig. 7 a, 7b represent such chart, wherein the working piston of most preferred embodiment (Fig. 7 a) and the regularization stroke of storage piston (Fig. 7 b) be expressed as the function of camshaft angle of swing,
Fig. 8 a, 8b represent such chart, wherein the working piston of most preferred embodiment (Fig. 8 a) and the regularization transfer rate of storage piston (Fig. 8 b) be expressed as the function of camshaft angle of swing,
Fig. 9 represents such chart, and wherein the regularization cam rotational speed of most preferred embodiment (normalizedcam rotational velocity) is expressed as the function of camshaft angle of swing,
Figure 10 a, 10b represent such chart, wherein the working piston of most preferred embodiment (Figure 10 a) and the regularization power of storage piston (Figure 10 b) be expressed as the function of camshaft angle of swing,
Figure 11 represents such chart, and wherein the regularization first derivative of the power on the working piston of most preferred embodiment is expressed as the function of camshaft angle of swing,
Figure 12 represents the principle layout chart of twin-stage gear train,
Figure 13 represents gear train, it comprise in two Z-shaped driving arms one of them and
Figure 14 represents along the longitdinal cross-section diagram of the flow direction of the most preferred embodiment of liquid end.
Embodiment
Mode of execution according to reciprocating pump of the present invention is shown in Figure 1.Pump 1 according to series connection conveying principle (serialdelivery principle) design comprises working piston/cylinder unit 2 and storage piston/cylinder unit 3.This working piston/cylinder unit 2 mainly comprises working piston 4, its to-and-fro motion in the cylinder space of working cylinder 5.Similarly, storage piston/cylinder unit 3 also comprises storage piston 6, and it moves back and forth in the cylinder space of storage cylinder body 7.Working piston 4 and storage piston 6 each drive unit drives of freely separating.Conspicuous in Fig. 1, two driver elements can be identical, therefore the driver element of following only detailed interpretation work piston 4.Described explanation is correct for storage piston 6 equally.
The driver element of working piston 4 comprises motor 8.In principle, all types of motors can be used as motor 8.Yet, traditional electric motor, for example direct current generator, magnetostriction system or piezo driven systems are preferred.Motor 8 combines with absolute type encoder unit (absolute encoder unit) 9, and is connected on the gear 10 with driving cam.By absolute type encoder unit 9, the position of driving cam in gear 10 monitored, and carries out related with respect to the stroke movement of working piston 4 in definite mode with correct polarization.This also can realize by the index plate (index disk) or the rotating coder (rotaryencoder) that combine with specific control software.
Motor 8 is by servo unit 11 controls, and the latter is connected to computing unit 12 successively.Control program and preferably tabular form be used for modulating or adapting to the specific control program of motor rotational speed according to difference compression correction factor, be to be stored in computing unit 12 or by calculating with other guide.
Between gear 10 and relevant piston (working piston 4 or storage piston 6), each power/torque transducer 13 be arranged among the driver of working piston/cylinder unit 2 or on, and be arranged among the driver of storage piston/cylinder unit 3 or on.Power/torque transducer 13 is being monitored power and/or the moment that applies or carry between separately piston and supply unit.Gear unit 10 is configured to the cam drive unit.The cam of described cam drive unit can have dynamics profile arbitrarily basically, yet always need provide such angular range, it is used to produce the precompressed stroke that starts delivery stroke, and is suitable for about discharge pressure and the constrictive maximization specific operation of medium condition.By keeping basic driver speed (modulate described basic driver speed in the excessive part that is not used according to as described below being limited to: promptly the stroke movement of working piston and storage piston produces the constant delivery stream that synthesizes according to the transfer rate of setting), described cam portion uses according to the system pressure scope in five equilibrium mode (in analiquot way).
Computing unit 12 is connected respectively to the drive unit of working piston/cylinder unit 2 via servo unit 11 and stores on the drive unit of piston/cylinder unit 3.As shown in phantom in Figure 1, computing unit 12 is also connected on absolute type encoder unit 9 and the power/torque transducer 13, and monitors and/or handle its measurement signal.
Working piston/cylinder unit 2 is included in the inlet valve 15 at its 14 places that enter the mouth at its inlet side, as unsteered safety check.Proportional valve unit 16 is arranged on before the described inlet valve, and it is equipped with four specific solenoid valves to be used to form low voltage side gradient form.Described Proportional valve unit is connected to computing unit 12 successively and is used to control purpose, and by described computing unit control.In pump operated process, by control ratio valve cell 16 compatibly, the medium that is transferred can be discharged from several storage 17a-17d.The solenoid valve of utilization Comparative Examples valve cell 16 in the induction stroke process of working piston 4 carries out programming Control, can by from storage or medium source 17a-17d alternately boot media enter the gradient that working cylinder 5 finishes on the suction side via inlet valve 15 and form.In the working piston 4 delivery stroke processes after induction stroke, the medium that is inhaled into working cylinder 5 is carried via the outlet 18 of working piston/cylinder unit 2, enters storage piston/cylinder unit 3 (valve wherein is not shown) via the outlet valve 19 that also is configured to non-control safety check and via inlet 21 in the situation of example.
Surveying flow from working piston/cylinder unit 2 to storage piston/cylinder unit 3 is to flow in the storage cylinder body 7 via inlet 21.The stroke movement of working piston 4 and storage piston 6 adapts to mutually as follows, promptly stores piston 6 and carry out its induction stroke simultaneously in the delivery stroke process of working piston 4.Correspondingly, working piston 4 delivers into storage piston/cylinder unit 3 on the one hand, enters pressure duct 20 by this unit on the other hand, has formed and has led to the supply line that is supplied to medium system.Owing to have this functional principle, do not have more medium compression to occur in the storage piston/cylinder unit 3.Medium is always under therein the system pressure.Compression and precompression are ad hoc carried out in working piston/cylinder unit 2.3 of storage piston/cylinder unit are used as storage and transport box, interrupt with the conveying of making (bridge) working piston/cylinder unit 2 in the induction stroke process up.Storage piston/cylinder unit 3 can form container, and its volume can be applicable to each operational condition.In the induction stroke process of working piston/cylinder unit 2, the volume that is stored in the storage piston/cylinder unit 3 is transported to the pressure duct 20 from storage piston/cylinder unit 3.
In the function extendible portion of native system, high-voltage samples injection valve 24 is set in the pressure duct 20 or is arranged on splitter 23 this pipeline back before.Be provided with monitor 28 in the outlet port of splitter 23, wherein can monitor chemical compound by it, described chemical compound is injected in company with volume of sample, and utilizes transport flow by differential delay (differntial retardation) elution from splitter according to the interval of the difference between separation phase (differential partition).By splitter 23 and monitor and the medium that is conducted is received in the waste receptacle 29.
The pump unit that Fig. 1 describes has for example also been represented for security reasons and the pressure transducer 25 that is provided with, be used for monitoring main pressure medium (system pressure) at pressure duct 20, the signaling line that its value is represented via dotted line is transported to computing unit 12 and is used for (backup) control purpose.Must be noted that additional pressure transducer 25 is optional rather than necessary, and only represent optional control apparatus.
The exemplary implementation and operation figure of the reciprocating pump that Fig. 2-6 expression is shown in Figure 1.In each chart, the angle of swing of camshaft is plotted on the abscissa in 0 ° to 360 ° the scope, and the specific angle of swing that wherein needs to consider is shown by emphasis.
Point A represents such camshaft angle of swing, and wherein the precompressed stage of working piston 40 finishes at this some place.B represents such angle of swing, and the medium transport that enters the high-pressure area at this some place only is subjected to the influence of working piston 4.C represents such angle of swing, is only stopped by the special medium transport that working piston 4 causes at this point.D represents such angle of swing, and Once you begin the sucting stage medium just begins to flow into from the area of low pressure cylinder space of working piston/cylinder unit 2 at this some place.In each chart of Fig. 1-6, its abscissa is represented the whole rotation (from 0 ° to 360 °) of camshaft.After the cam section of utilizing from 0 angle of rotation to an E (this E rotates through complete 360 ° corresponding to camshaft), whole work cycle begins (the last figure among Fig. 2) at the delivery stroke of this some place working piston 4 from the position 0 once more.
Working piston 4 only produces precompressed from 0 to the A stroke of carrying out.In the process of carrying out this stroke range, inlet valve 15 and outlet valve 19 all keep closing (Fig. 6).Storage piston 6 is carried out its a part of delivery stroke (Fig. 2 figure below) in the identical rotating range of its driving cam.As seeing in Fig. 3, to enter pressure duct 20 be only to be undertaken by storage piston/cylinder unit 3 to fed sheet of a media in this rotation angle range.The transfer rate full consumption that obtains by working piston/cylinder unit 2 is used for precompressed (the last figure of Fig. 3): the piston displacement action is not carried and is pumped medium, but only it is compressed.Fig. 4-5 has shown the regularization power in working piston 4 and 6 existence of storage piston, and the regularization power that exists at working piston 4 changes (normalized alteration of theforce) (first derivative at regularization power cam stroke position place).The last figure expression of Fig. 4, the power on the working piston 4 in 0 to A rotation angle range steadily and if necessary to increase in constant mode.This also can reach a conclusion from Fig. 5, and Fig. 5 represents that the power on the working piston 4 changes.
When arriving the some A of camshaft angle of swing, the medium in the cylinder space of working piston/cylinder unit 2 obtains precompressed according to the system pressure on the high pressure side.This means that the precompressed stage finishes.The last figure of Fig. 6 expresses mouthful valve 19 and opens at this time point.The stroke of working piston 4 advances with constant speed, as 0 and A between the precompressed stage (the last figure of Fig. 2) in, and with 0 and A between the process in precompressed stage compare the stroke of storage piston 6 lag behind slightly (Fig. 2 figure below).Fig. 3 represents, in the scope between A and B, compares with the precompressed phase process between 0 to A, and the regularization displacement action of storage piston 6 slightly reduces, and the reduction amount is the regularization displacement action amount (it is corresponding to the expression value of last figure) of working piston 4.The displacement action of working piston 4 no longer consumes the precompressed that is used for scope between A and B.This causes the following fact: storage piston 6 and working piston 4 both's fed sheet of a media enter into pressure duct 20.Shown in the power schematic representation of Figure 4 and 5, all keep constant in regularization power on the working piston 4 and the regularization power on storage piston 6.
At rotary angle position C, storage piston 6 reaches the top dead center of its stroke movement, fills the end of stroke.At this point, the conversion from the induction stroke to the delivery stroke has taken place, cause reverse (Fig. 2 figure below) of moving.In the scope between B and C, the medium transport that enters pressure duct 20 is only based on the displacement action of working piston 4.
Between B and C, be compared to the stroke in precompressed stage (0-A) process and be compared to working piston 4 and the common delivery phase (A-B) of storage piston 6, working piston 4 increases (the last figure of Fig. 2) significantly with respect to the stroke of angle of swing.As can see beginning and the termination in the scope of B and C respectively of the induction stroke of storage piston 6 from Fig. 2 figure below.The carrying capacity of working piston 4 between B and C scope be corresponding to the regularization power in the scope between A and B because working piston 4 constantly the system pressure on the high pressure side (rated pressure, nominal pressure) carry down.Figure below of Fig. 4 represents that also owing to continue to be exposed to system pressure, the regularization power of carrying at storage piston 6 places also keeps constant in induction stroke.Its reason is that storage piston 6 all is under the system pressure at inlet side and outlet side.With reference to whole pumping circulation, the theoretic constant process of power value curve representation.Described curve is parallel to the x axis and extends, because the storage piston is exposed under the whole hydrostatic pressure (this hydrostatic pressure is subjected to the domination at the system pressure outside the pump discharge) constantly.
Changed along with system pressure by the additional force that friction produced between piston and its Sealing, this system pressure is being arranged at contact area the sealing lip of Sealing is being pressed on power on the piston face.Yet, described frictional force only reach by hydrostatics be applied to the part of the power value on the monitored pump structure.Sealing frictional force is superimposed upon on the hydrostatic in the mode that increases and reduce.The actual curve of the power value that observation is monitored in the pump cyclic process can be found, the stack of frictional force is rendered as (very little) and is offset step by step, thereby increasing or reducing is to depend on the stroke of piston travel direction: it is relevant with displacement stroke (0-B and C-E part) to increase effect (as shown in Figure 4), and it is relevant with filling stroke (B-C part) to reduce effect.
As can be seen from Figure 3, the regularization displacement action (normalized displacement action) of storage piston 6 in (in the induction stroke process) scope between B and the C becomes negative value.The regularization displacement action of working piston 4 surpasses size this value just of the associating displacement action of two pistons, and described displacement action illustrates by dot and dash line in Fig. 3.In the scope, the displacement action of working piston 4 is divided in its induction stroke process, is pumped the medium bulking value that enters pressure duct 20 and is received in the medium bulking value of storing in the piston/cylinder unit 3 by storage piston/cylinder unit 3 between B and C.
At rotary angle position C, working piston 4 is positioned at its top dead center (end of displacement stroke), and storage piston 6 (is filled the end of stroke) at its lower dead center center.At this rotary angle position C, the stroke movement of working piston 4 and storage piston 6 is along advancing on the opposite separately direction.This can obviously find out from the precipitous decline of regularization power shown in the last figure of Fig. 4, that working piston 4 occurs.The delivery phase of working piston 4 stops when arriving angle of swing C, and the displacement action of storage piston 6 start from after stage, the whole displacement action of storage piston is corresponding to the combination displacement action (Fig. 3) of working piston 4 and storage piston 6.At angle of swing C, outlet valve 19 (it is associated with working piston) cuts out and prevents that medium from flowing back to the cylinder space 5 of working piston/cylinder unit 2 from the high pressure side.
Inlet valve 15 is lingeringly opened.This is especially obvious in the comparison diagram of Fig. 6, therefrom can see: 15 of inlet valves are opened at angle of swing D place.In the rotation angle range between C and D, from working piston/cylinder unit 2, discharge, the volume to external pressure but the harmful dead space volume that still is compressed to system pressure in delivery stroke before can reexpand.Therefore, in the described expansion stage, medium can not be inhaled in the cylinder space 5 of working piston/cylinder unit 2 from low voltage side.Correspondingly, the regularization power that exists on working piston 4 is basic only reaches 0 value at rotary angle position D place.
At rotary angle position D place, be used for the cylinder space 5 that the required negative pressure of actual startup induction stroke is created in working piston/cylinder unit 2.In this process, inlet valve 15 is opened (the last figure of Fig. 6), and the induction stroke of working piston 4 begins to carry out until arrive top dead center at angle of swing E place at a D.In the scope of D and E and in the scope of C and D, medium enters the conveying of pressure duct 20 only based on the displacement action of storing piston 6 from pump.In rotary angle position E (this position is corresponding to angle of swing 0), above-mentioned circulation repeats.
Pressure transducer 25 is set at storage piston/cylinder unit 3 back in pressure duct 20.This sensor does not require and is used to carry out the method according to this invention, and therefore omits in principle.In an illustrated embodiment, pressure transducer 25 (shown in dotted line) preferably is connected to computing unit 12 by signal pipe line.By with its with compare by power/torque transducer 13 measured values that obtain, the measured pressure value that is provided by pressure transducer 25 for example allows to infer relevant for losing efficacy and the reason (comprising the inefficacy of whole system 1 and the reason of fault) of fault.
In most preferred embodiments, enforcement of the present invention is based on double-piston serial type pump 1 (it comprises " working piston " 4 and " storage piston " 6), and described pump 1 has single DC motor 8, and it is combined with the tape drive 40 that makes twin cam shaft 41 rotations.Rotatablely moving of cam disk 42 profiles changed into straight reciprocating motion by the roller 43 in Z type driving arm 44 attached proximal ends.Utilize axial ball bearing, driving arm 44 carries out their to-and-fro motion along accurate leading axle, realizes stable against the inclined-plane by the roller bearing of cross setting simultaneously.And, driven plunger 4,6 each far-end at them are equipped with hard contact lever 45 in carriage holding member 46, the low friction opposed surface of described bar provides load free floating, no side direction that causes connection between driver and pumping piston 4,6 together with the forked type spring simultaneously.
In order to allow to continue to monitor depending on the discharge pressure that is pumped medium and the liquid displacement process of specific compression, task driven arm 44 is equipped with strainometer.By this strainometer 49, the efficient of pumping and filling stroke can continue in each pumping circulation and accurately monitoring, and the processing of its signal trajectory has been formed fast and the effectively basis of feedback, with the compensation pumping fluid under high operation pressure and the highest operation pressure specific compression to the influence of pump-conveying property and efficient.Examination comparison diagram 10a and 10b.
According to U. S. Patent the 5th, 653,876, relevant liquid displacement assembly (LDA) is designed to sandwich structure.
The dynamics data that is used for the driving cam dish 42 of working piston 4 and storage piston 6 is represented in the drawings, described figure has shown with respect to the maximum stroke amplitude of working piston 4 and has carried out regularization lift (elevationnormalised), and covered whole pumping circulation (360 °) (wherein Fig. 7 a and 7b represent working piston 4 and storage piston 6 separately).Relevant cam is used to represent used cam profile with reference to angle A to E.These figure need compare with the ideal curve figure of Fig. 2.
Cover whole pumping circulation (360 °), in Fig. 8 a and 8b (representing work and storage piston separately), shown to have the actual regularization transfer rate (actual normaliseddelivery rate) of given cam profile under Constant Angular Velocity and the relation of cam angle degree position.Relevant cam represents to be used for really (implementing used) cam profile with reference to angle A to E.These figure need compare with the ideal curve figure of Fig. 3.
Example ground shows in Fig. 9: have in each pumping circulation process under the situation of enough compressibility compensation deals steps, as the true measured angular speed of cam angle degree position function.Between A and B, promptly in suitable pre-voltage levels after the A point reaches, motor speed descends in control period as follows, be that the cam rotational speed drops to about 40%, and the cam rotational speed is increased to its initial rating value (nominal value) once more in such a way subsequently, promptly produces synthetic constant delivery stream by two pistons.
In desirable method, slowing down, almost moment finishes inherently, but because outlet non-return valve in the mode of negligible delay by hydraulic actuating, and then the acceleration of specified cam speed (nomind cam velocity) is to be undertaken synchronously by the cam driver profile until a B.Is processed as the single order inverse of the monitored power at working piston place at A in control unit to the feedback trigger event in the B part, as the function of camshaft angle of swing.
In case continuously adopting the controlling method of having described to realize complete compressibility compensation control circle in the circulation, the true regularization power that is obtained by force sensor measuring as shown in figure 10.Typically, need carry out 2 to 3 pump stroke circulations, set up flox condition stable and that continue up to high-pressure outlet side place in system.
Shown signal trajectory is equal to the ideal trajectory among Fig. 4.The negative power of the smaller value characteristic of measuring at working piston 4 places from angle of swing part D to E has quantized to avoid the friction force value of the piston seal of hydraulic load, and inlet non-return valve 38 is opened to be used to fill stroke simultaneously.According to the signal of piston motion, storage piston force sensor measurement alternately effectively friction, should be alternately effectively friction result from the influence that associated seal causes, the sealing part is under the load effect according to system back pressure forever.Actual measured value is mainly caused by the nonlinearity erron of seal friction with respect to the less deviation of theoretical value.
As previously mentioned, seal friction power is superimposed upon on the static pressure in the mode that increases or reduce.Observation is monitored the actual curve of the power value that obtains and can be found in the pumping circulation process, it is the moving direction that depends on stroke of piston that the stack of frictional force shows as relatively little skew step by step (and then increase or reduce): increase effect (shown in Figure 10 b) and be associated with displacement stroke (0-B and C-E part), be associated with filling stroke (B-C part) and reduce effect.
The actual regularization first derivative of measured power as shown in figure 11.It is equal to Fig. 5.Shown signal trajectory original and not amount of decrease has noise, also shown on the desired level value amplitude with the difference pumping circulation different phase.
In a preferred embodiment, the Maxon Moter that has graphite brush
TMThe motor of RE 268214 is used.Yet, have suitable power rating, enough moment and high bandwidth rotational speed specification and coupling or exceed any DC motor of described motor performance, all will be enough to drive described pumping system.
The principle layout chart of twin-stage gear train has been described in Figure 12.Use commercial available gear, described twin-stage gear train can be made according to known design.Be used to produce required dynamic speed of given flow rate scope (dynamic velocity) and acceleration range and reach by twin-stage band drive system, this twin-stage band drive system provides 100: 1 reduction speed ratio.By above-mentioned principle, this gear train is corresponding to traditional and commercial available design.
Figure 13 has represented the cross-sectional view of gear train, and it comprises one or main piston in two Z-shaped driving arms 44.Driven plunger 44 is equipped with axial ball bearing 47, to carry out their to-and-fro motion along accurate leading axle.They each activated by cam profile 42 via roller 43 at its near-end, be the reciprocating piston stroke movement with the rotating cam movement conversion.At their far-end, driven plunger 44 is being carried the contact lever of being made by hard material 45 in pinching end parts 48, and this contact lever has the low friction apparent surface who is used for pumping piston 44.Combine with the forked type spring, described surface guarantees that the free floating between actuation ends and pumping piston axle 45 connects.
Be fixed in the countersink for 49 bonded doses at the appreciable strainometer in the left side of driven plunger 44 " arm ".For clarity sake, this strainometer 49 is exaggerated and has shown.In the present embodiment, gear train all is identical for working piston 4 with storage piston 6, has therefore only represented one and half ones of gear train.In possible force sensing apparatus, the force transducer type of using in the most preferred embodiment is based on known resistance strain gage principle.Described strainometer 49 is fixed by the binder of sclerosis, and is positioned at the cantilever portion of Z-shaped driven plunger 44 easily, and flexural strain and/or shearing strain reach their maximum detection value herein.
Used the commercial resistance strain gage 49 that obtains and become industrial standard, for example Vishay
TMType062LV.The resistance strain gage of described type is most appropriate to the measurement (it comprises the wheatstone bridge configuration of full balance) of shearing strain.Realize that the required force transducer of feedback pump control principle of the present invention is integrated in driven plunger 44 structures with working piston 4 associated, and also be integrated into alternatively and store in the driven plunger 44 of piston 6 associated.
Shown in Figure 14 is along the longitdinal cross-section diagram of the flow direction of the most preferred embodiment of liquid end.
Reference numerals list
1 pump, 28 monitors
2 working pistons/cylinder unit 29 waste canisters
3 storage piston/cylinder unit, 30 liquid displacement package shells
4 working pistons (angeschnitten)
5 working cylinders, 31 storage displacement chambeies
6 storage pistons, 32 high pressure piston seals
7 storage cylinder bodies, 33 driving/pumping piston interface compression elements
8 motors, 34 outlet non-return valve unit
35 work shift chambeies, 9 absolute type encoder unit
10 gears, 36 high pressure piston seals
11 servo control units, 37 driving/pumping piston interface compression elements
12 computing units, 38 inlet non-return valve unit
13 power/torque sensor 39 is used for the intake assembly of ratio solenoid
Entrance bearing 4 ports of 14 working pistons/cylinder unit (showing wherein 2)
15 inlet valves, 40 tape drives
16 Proportional valve unit, 41 twin cam shafts
The 17a-17d medium source, solvent storage 42 cam disks
19 outlet valve 44Z type-driving arm or pistons
20 pressure ducts, 45 contact levers
The inlet 46 carriage holding members of 21 storage piston/cylinder unit
23 splitters, 48 pinching end parts
24 sample injection valves, 49 strainometers
25 pressure transducers
26 control programs
27 control program tables
Claims (28)
1. a reciprocating pump (1), especially a kind of double-piston pump, it is used to produce the transport flow for the treatment of fed sheet of a media, and this transport flow is not pulsation basically, and described reciprocating pump comprises:
At least two piston/cylinder units (2,3), its described medium transport that is used for flowing out the area of low pressure enters the high-pressure area,
Driver element (8,10), it is used for driven plunger cylinder unit (2,3),
Control unit (11,12), its be used to control this driver element the speed that is driven and
Sensor (13), it is used for the actual value of acquisition controlling parameter, and the degree of pulsatility of wherein utilizing this actual value to make to produce in the high-pressure area that flows can be derived,
Wherein, described sensor (13) be suitable for being captured among the structure of at least one piston/cylinder unit (2,3) and/or driver element (8,10)/the place mechanical force that applies/transmit and/or the value of moment.
2. reciprocating pump according to claim 1 is characterized in that also comprising:
By being pumped the zone that medium is got wet; With
The arid region of in operating process, not got wet by medium,
Wherein, described sensor (13) is positioned at the arid region of this pump (1), and the medium of carrying is not got wet.
3. reciprocating pump according to claim 1 and 2, wherein said sensor (13) be suitable for being captured among piston/cylinder unit (2,3) or the driver element (8,10)/on the tensile stress, compressive stress, shearing stress and/or the Buckling stress that are applied in/transmit.
4. according to each described reciprocating pump among the claim 1-3, wherein said sensor (3) is based on strainometer, piezoelectric element, optical measuring instrument or acoustic resonator.
5. according at the described reciprocating pump of preceding arbitrary claim, wherein said reciprocating pump is a double-piston pump in parallel.
6. according to each described reciprocating pump among the claim 1-4, described reciprocating pump is the double-piston pump of series connection.
7. according at the described reciprocating pump of preceding arbitrary claim, wherein each piston/cylinder unit (2,3) is by independent drive unit drives.
8. according at the described reciprocating pump of preceding arbitrary claim, wherein each driver element is by independent motor driving.
9. according at the described reciprocating pump of preceding arbitrary claim, wherein first piston cylinder unit (2) (working piston unit) is connected with the area of low pressure phase fluid in its suction side, and its discharge side in parallel fluid be connected to second piston/cylinder unit (3) (storage piston unit) and high-pressure area.
10. reciprocating pump according to claim 9, wherein said storage piston unit (3) carry out hydraulic pressure via its discharge side with the high-pressure area and are connected.
11. according to claim 9 or 10 described reciprocating pumps, wherein said sensor (13) monitoring among the driver (8,10) of the structure of described working piston unit (2) and/or described working piston unit (2)/on the mechanical force and/or the moment that are applied in/transmit.
12. reciprocating pump according to claim 11, one of them additional sensor (13) monitoring among the driver (8,10) of the structure of described storage piston unit (3) and/or storage piston unit (3)/on the mechanical force and/or the moment that are applied in/transmit.
13. according at the described reciprocating pump of preceding arbitrary claim, wherein said driver element (10) is designed to produce the precompressed stroke.
14. according at the described reciprocating pump of preceding arbitrary claim, wherein said driver element (10) comprises cam driver.
15. one kind is used for control piston pump (1), especially controls the method for double-piston pump, the medium transport that described reciprocating pump is used for flowing out from the area of low pressure enters the high-pressure area, and described reciprocating pump comprises: at least two piston/cylinder units (2,3); Driver element (8,10), it is used to drive in the described piston/cylinder unit (2,3) at least one; And sensor (13), its be used for monitoring among the structure or driver element (8,10) of piston/cylinder unit (2,3)/on the mechanical force and/or the moment that are applied in/transmit;
Described method comprises following treatment step:
I) with first speed (n) by driver element (8,10) drive at least one piston/cylinder unit (2,3), and then monitor at described piston/cylinder unit (2 by sensor (13), 3) structure and/or described driver element (8,10) among/on the mechanical force and/or the moment that are applied in/carry
Ii) by adopting the described mechanical force that monitored by described sensor (13) and/or the value of moment, that comes that monitoring stream goes out piston/cylinder unit (2,3) is pumped the actual moment that begins to deliver into the high-pressure area of medium,
Iii) monitor at the actual compression ratio that is pumped medium when beginning to carry, especially monitor the compression ratio that is pumped medium when overvoltage or under-voltage the appearance,
Iv) as follows the driver element rotational speed is modulated to second speed (n+1), that is: variation compression ratio that causes owing to the change system back pressure and/or the variation compressibility that is pumped medium that occurs in the high pressure side are compensated, and produced the pulseless basically transport flow that is pumped medium in the high-pressure area
V) by will step I in v) modulated driver element rotational speed (n+1) make all repetition methods step I of each pumping circulation as first speed (n)) to step I v).
16. method according to claim 15 is wherein at step I i) in, the process of the value of measurement mechanical power and/or moment is monitored.
17. according to claim 15 or 16 described methods, wherein in the single pump stroke process under constant drive unit rotational speed, monitoring is at step I i) in mechanical force and/or moment or their measured value processes.
18. according to each described method among the claim 15-17, wherein Cun Chu working procedure is used for the driver element rotational speed is modulated.
19. method according to claim 18 wherein based on carrying actual beginning and obtain correction factor, and depends on this correction factor and selects specific rotational speed control program.
20. according to each described method among the claim 15-19, wherein in step I) in used the rotational speed control program, it is modulated onto the flow velocity that sets on pump.
21. according to each described method among the claim 15-20, the medium that wherein is pumped is subjected to precompressed when the beginning of each pumping circulation.
22. method according to claim 21, the secondary correction factor that wherein on the driver element rotational speed, superposeing, its compensation is by precompressed excessive transport flow that produce, for the volume under the external pressure.
23. according to claim 20 or 22 described methods, wherein said precompressed stroke is suitable for being estimated to be used for the appointment maximum delivery pressure and the maximum specific compression of pumped medium.
24. according to each described method among the claim 20-23, wherein said driver element rotational speed reduces when modulated in the precompressed stroke procedure.
25. according to each described method among the claim 15-24, wherein utilize the composition of the medium that pump carries to change, especially change according to control program.
26. according to each described method among the claim 15-25, wherein to the following volume flow rate of each pumping circulation monitoring, so that determining the charging efficiency that produces owing to described volumetric expansion when induction stroke begins loses: described volume flow rate can not be from the piston/cylinder unit (2 of working piston as harmful dead space volume, 3) be discharged from the displacement region, but still have to before actual pumping begins, be compressed according to current operational condition.
27. according to each described method in claim 25 or 26, the gradient composition that wherein is used for filling subsequently stroke is to revise according to the expansion of not discharging harmful dead space volume in the displacement region of the piston/cylinder unit (2,3) of working piston.
28. according to each described method among the claim 15-27, wherein said driver element (2,3) is a cam driver.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE102008017167 | 2008-04-02 | ||
| EP08170712.7 | 2008-12-04 | ||
| EP08170712A EP2107241A3 (en) | 2008-04-02 | 2008-12-04 | A Piston Pump Having a Force Sensor and a Method for Controlling Said Pump |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN101865108A true CN101865108A (en) | 2010-10-20 |
Family
ID=40823579
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200911000080A Pending CN101865108A (en) | 2008-04-02 | 2009-12-04 | Have the reciprocating pump of force transducer and be used to control the method for described reciprocating pump |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US20100143155A1 (en) |
| EP (1) | EP2107241A3 (en) |
| CN (1) | CN101865108A (en) |
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| CN103967763A (en) * | 2013-01-31 | 2014-08-06 | 北京七星华创电子股份有限公司 | Speed control device and method for two-stage tandem pumps |
| CN107407266A (en) * | 2015-03-09 | 2017-11-28 | 韦尔矿物荷兰有限公司 | Hydraulic pump system for handling slurry media |
| CN107860846A (en) * | 2017-11-10 | 2018-03-30 | 广东恒畅环保节能检测科技有限公司 | A kind of ion chromatograph |
| CN109195711A (en) * | 2016-05-17 | 2019-01-11 | 杜尔系统股份公司 | coating agent pump |
| CN112324648A (en) * | 2020-11-02 | 2021-02-05 | 山东悟空仪器有限公司 | Control method of pressure balance point of serial plunger pump and serial plunger pump |
| CN114562453A (en) * | 2022-02-09 | 2022-05-31 | 三一汽车制造有限公司 | Engineering vehicle and pumping operation control method and device thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4352636A (en) * | 1980-04-14 | 1982-10-05 | Spectra-Physics, Inc. | Dual piston pump |
| US4681513A (en) * | 1985-02-01 | 1987-07-21 | Jeol Ltd. | Two-stage pump assembly |
| US5664937A (en) * | 1994-02-03 | 1997-09-09 | Hitachi, Ltd. | Precisely flow-controlling pump |
| US20050061722A1 (en) * | 2003-09-18 | 2005-03-24 | Kunihiko Takao | Pump, pump for liquid chromatography, and liquid chromatography apparatus |
Family Cites Families (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2275532A (en) * | 1939-04-18 | 1942-03-10 | Westinghouse Electric & Mfg Co | Oil well strain gauge |
| DE2158968A1 (en) * | 1970-04-24 | 1973-05-30 | Krauss Maffei Ag | Controlling injection machine - esp for cellular plastics by regulating differential pressure across actuating piston |
| US4359312A (en) * | 1978-08-15 | 1982-11-16 | Zumtobel Kg | Reciprocating pump for the pulsation-free delivery of a liquid |
| US4644785A (en) * | 1985-09-06 | 1987-02-24 | Fmc Corporation | Hinged strain cell mounting apparatus |
| DE3785207T2 (en) * | 1987-09-26 | 1993-07-15 | Hewlett Packard Gmbh | PUMP DEVICE FOR DISPENSING LIQUID AT HIGH PRESSURE. |
| US5026255A (en) * | 1988-11-18 | 1991-06-25 | Clarence W. Carpenter | Pulseless pump apparatus having pressure crossover detector and control means |
| ATE178975T1 (en) | 1992-10-28 | 1999-04-15 | Flux Instr Ag | HIGH PRESSURE PUMP FOR FINE FLUID DOSING |
| JP3491948B2 (en) * | 1993-03-05 | 2004-02-03 | ウォーターズ・インベストメンツ・リミテッド | Solvent pump feeder |
| JP3291258B2 (en) * | 1998-10-14 | 2002-06-10 | 太陽鉄工株式会社 | Fluid pressure cylinder device |
| US6292757B1 (en) * | 1999-08-16 | 2001-09-18 | Windrock, Inc. | Method and apparatus for continuously monitoring parameters of reciprocating compressor cylinders |
| US6520930B2 (en) * | 1999-11-24 | 2003-02-18 | Medrad, Inc. | Injectors, injector systems and injector control |
| US20030062026A1 (en) * | 2000-09-07 | 2003-04-03 | Friedrich Boecking | Common rail system |
| DE50111054D1 (en) * | 2001-12-21 | 2006-11-02 | Agilent Technologies Inc | Method of providing volumetric flows of fluids |
| US6882960B2 (en) * | 2003-02-21 | 2005-04-19 | J. Davis Miller | System and method for power pump performance monitoring and analysis |
| US7186094B2 (en) * | 2003-03-26 | 2007-03-06 | Gas Machinery Research Council | Method and apparatus for measuring work performed by a compressor |
| US7056097B2 (en) * | 2003-07-30 | 2006-06-06 | Equistar Chemicals L.P. | System and method for monitoring the mechanical condition of a reciprocating compressor |
| US8313308B2 (en) * | 2004-03-26 | 2012-11-20 | Hospira, Inc. | Medical infusion pump with closed loop stroke feedback system and method |
| GB0425688D0 (en) * | 2004-11-23 | 2004-12-22 | Spicket Valves & Pumps Ltd | Monitoring system |
-
2008
- 2008-12-04 EP EP08170712A patent/EP2107241A3/en not_active Withdrawn
-
2009
- 2009-12-04 CN CN200911000080A patent/CN101865108A/en active Pending
- 2009-12-04 US US12/631,695 patent/US20100143155A1/en not_active Abandoned
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4352636A (en) * | 1980-04-14 | 1982-10-05 | Spectra-Physics, Inc. | Dual piston pump |
| US4681513A (en) * | 1985-02-01 | 1987-07-21 | Jeol Ltd. | Two-stage pump assembly |
| US5664937A (en) * | 1994-02-03 | 1997-09-09 | Hitachi, Ltd. | Precisely flow-controlling pump |
| US20050061722A1 (en) * | 2003-09-18 | 2005-03-24 | Kunihiko Takao | Pump, pump for liquid chromatography, and liquid chromatography apparatus |
Cited By (9)
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|---|---|---|---|---|
| CN103967763A (en) * | 2013-01-31 | 2014-08-06 | 北京七星华创电子股份有限公司 | Speed control device and method for two-stage tandem pumps |
| CN103967763B (en) * | 2013-01-31 | 2016-03-02 | 北京七星华创电子股份有限公司 | A kind of control gear of two-stage tandem pump speed and method |
| CN107407266A (en) * | 2015-03-09 | 2017-11-28 | 韦尔矿物荷兰有限公司 | Hydraulic pump system for handling slurry media |
| CN107407266B (en) * | 2015-03-09 | 2021-06-08 | 韦尔矿物荷兰有限公司 | Hydraulic Pump System for Handling Slurry Media |
| CN109195711A (en) * | 2016-05-17 | 2019-01-11 | 杜尔系统股份公司 | coating agent pump |
| CN107860846A (en) * | 2017-11-10 | 2018-03-30 | 广东恒畅环保节能检测科技有限公司 | A kind of ion chromatograph |
| CN112324648A (en) * | 2020-11-02 | 2021-02-05 | 山东悟空仪器有限公司 | Control method of pressure balance point of serial plunger pump and serial plunger pump |
| CN114562453A (en) * | 2022-02-09 | 2022-05-31 | 三一汽车制造有限公司 | Engineering vehicle and pumping operation control method and device thereof |
| CN114562453B (en) * | 2022-02-09 | 2024-01-30 | 三一汽车制造有限公司 | An engineering vehicle and a control method and device for its pumping operation |
Also Published As
| Publication number | Publication date |
|---|---|
| EP2107241A3 (en) | 2010-06-09 |
| EP2107241A2 (en) | 2009-10-07 |
| US20100143155A1 (en) | 2010-06-10 |
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