DE102023111962A1 - Device and method for disinfection of liquid media - Google Patents

Abstract

The invention relates to a device for disinfecting liquid media, wherein the liquid medium is exposed to UV rays in a continuous process by means of at least one UV lamp and the UV lamp is separated from the medium flowing past by means of at least one transparent element, wherein the device has at least one ultrasonic element which exposes at least the transparent element to ultrasonic vibrations.
According to the method, the liquid medium is exposed to UV rays in a continuous process by means of at least one UV lamp and the UV lamp is separated from the medium flowing past by means of at least one transparent element and the liquid medium is exposed to the UV rays through the transparent element, wherein during the continuous process ultrasonic vibrations are generated by means of at least one ultrasonic element, which prevent the formation of deposits and/or remove existing deposits at least on the transparent element.

Description

The invention relates to a device and a method for disinfecting liquid media according to the preamble of the first and ninth patent claims.

For example, circulating cooling lubricants and drilling emulsions in machines in the metalworking industry (e.g. turning, milling, grinding) are subject to a constant growth of microorganisms, e.g. bacteria and fungi. The conditions prevailing in the machines and storage tanks, such as temperature and nutrient content, promote the growth of microorganisms. The decomposition of the lubricants leads to a reduction in the cooling and lubricating performance and the resulting decomposition products cause very unpleasant odors.

Another disadvantage is that the formation of aerosols in the engine room leads to contact between the operator and the microorganisms, which often leads to rashes on the skin or respiratory diseases.

One way to counteract this is, for example, chemically disinfecting the coolant by adding disinfectants directly to the storage tank. This should be done immediately after cleaning the machine and when adding fresh coolant, so that growth is prevented from the outset. It is important to ensure that a sufficient amount of disinfectant is added in accordance with the amount of coolant.

If the concentration is too low, sufficient effect cannot be achieved. During operation, the concentration of the disinfectant also decreases steadily due to the disinfectant effect, outgassing and thermal decomposition on the hot workpiece. Due to the aerosol formation described above, the operator also comes into contact with the disinfectant, which can also lead to skin rashes.

Regular monitoring of the concentration of disinfectant and re-dosing involve effort and costs.

Another option is to physically clean the coolant. Filter systems with coalescence separators are often used to separate foreign oils and solids. These devices are very difficult to operate and, due to their high price, are often designed as mobile devices so that the coolant can be processed in several machines. The machines cannot remain in operation while the coolant is being processed. In addition, microorganisms remain in the medium and, in the worst case, can be carried over to other machines. To counteract this, some manufacturers can install UVC systems to disinfect the coolant. However, these systems also have to be cleaned and maintained. Alternatively, disinfectants are added, which has the disadvantages already described.

From the publication DD 255 358 A1 For example, a process is known for increasing the service life of aqueous cooling lubricants. Biocides made from copper compounds are used, which are said to have a very good effect on the cooling lubricants mentioned, even at low concentrations. However, copper can be harmful to health; high doses can, for example, lead to liver damage.

In the printed publication WO 2012/219243 A1 A device and a method for cleaning and recovering used lubricants and/or cooling lubricants is described. The used and centrifuged lubricant and/or cooling lubricant total flow is passed through at least one pipeline into at least one UV reactor, in which the lubricant and/or cooling lubricant total flow is treated to kill off the bacteria contained therein.

Microorganisms are irradiated with microbicidal UV radiation from at least one UV lamp. A flat bed reactor or a falling film reactor is used as the UV reactor, in which the at least one UV lamp is arranged in the center of a downpipe. The lubricant and/or cooling lubricant cleaned and recovered in this way is passed through at least one pipe into at least one collection container. The collection container can have at least one agitation agent, which is selected, for example, from the group consisting of Vibramax shakers, ultrasonic baths, ultrasonic lances and mechanical stirrers. The agitation agents are intended to homogenize split lubricants and/or cooling lubricants again. A separation of liquid and/or solid particles from liquids can also be provided, which includes, among other things, at least one acoustophoresis device or acoustoaggregation device for concentrating, agglomerating and/or aggregating liquid and/or solid particles in a liquid using standing ultrasonic waves.

This solution is achieved by using a UV flatbed reactor or a UV falling film reactor, whose UV emitter is arranged in the center of a fall pipe, is relatively complex.

The basic aim of the solutions described above is to extend the service life of cooling lubricants.

The disadvantage of the aforementioned variants, which use UV radiation, is that the surfaces over which the medium flows can become dirty and that the solutions are relatively complex

The object of the invention is therefore to provide a device for disinfecting liquid media by UV disinfection, which has a simple and cost-effective construction.

This object is achieved according to the invention by the features of the first and ninth patent claims.

Advantageous embodiments emerge from the subclaims.

The device for disinfecting liquid media, wherein the liquid medium is exposed to UV rays in a continuous process by means of at least one UV lamp and the UV lamp is separated from the medium flowing past by means of at least one transparent element, has at least one ultrasonic element which exposes at least the transparent element to ultrasonic vibrations.

The device preferably has at least one irradiation chamber with at least one channel through which the medium flows, wherein one or more UV emitters are arranged in the chamber, which are separated from the medium by the transparent element. At least one ultrasonic element is arranged on an outer wall of the chamber, the vibrations of which prevent or remove deposits on a surface of the transparent element past which the medium flows.

In an advantageous embodiment, the irradiation chamber is formed from a hollow profile with a polygonal cross-section, in particular a rectangular or square one.

In a particularly preferred embodiment of the device, at least one or more UV emitters extending along a longitudinal axis of the hollow profile are arranged in the hollow profile, the UV emitter(s) being encased in a glass tube around which the medium flows. Additionally or alternatively, a transparent liquid-tight partition is arranged between the UV emitter(s) and the medium. On the outer wall of the chamber, several ultrasonic elements are arranged one above the other and/or next to each other in relation to the longitudinal axis.

The flowing medium is preferably supplied to the irradiation chamber via a supply line and a discharge line.

In an advantageous embodiment, the medium is a cooling-lubricating liquid of a machine tool, with the supply line and the discharge line being connected to a container of the cooling-lubricating liquid. The circulating medium is pumped from the container through the irradiation chamber and back into the container.

The supply and discharge lines of the container for the cooling-lubricating liquid are preferably arranged at half the height of the container or above and particularly preferably on opposite sides.

The medium is liquid, which refers to media in which deposits or contaminants settle, particularly on the transparent elements.

The transparent element is preferably made of quartz glass.

The UV lamps used in the device are preferably UVC lamps. In particular, two types of UVC lamps are present, with a first type of UVC lamp generating UVC light with a wavelength of 254nm and a second type of UVC lamp generating UVC light with a wavelength of 185nm. The wavelength of 254nm is used purely for disinfection within the UVC chamber. The wavelength of 185nm, on the other hand, also generates ozone or free radicals in the device.

These radicals are removed from the UVC chamber and ensure additional disinfection in the pipes and storage tank.

With the method according to the invention for disinfecting liquid media, with a device according to the invention, the liquid medium is exposed to UV rays in a continuous process by means of at least one UV lamp, wherein the UV lamp is separated from the medium flowing past by means of at least one transparent element. The liquid medium is exposed to the UV rays through the transparent element in such a way that ultrasonic vibrations are generated during the continuous process by means of at least one ultrasonic element. which prevent the formation of deposits and/or remove existing deposits at least on the transparent element.

In an advantageous embodiment of the method, the ultrasonic vibrations are permanent during the disinfection process. Alternatively, the ultrasonic vibrations are generated at fixed intervals.

The invention is explained in more detail below using an embodiment and associated drawings:

• 1 eine Vorrichtung zum Entkeimen von flüssigen Medien mit einem UV-Strahler in der Vorderansicht
• 2 die Vorrichtung nach 1 in der Seitenansicht,
• 3 eine Vorrichtung zum Entkeimen von flüssigen Medien mit zwei nebeneinander angeordneten UV-Strahlern in der Vorderansicht,
• 4 die Vorrichtung nach 3 in der Seitenansicht,
• 5 oberer Aufnahmebereich gemäß 3 und 4,
• 6 unterer Aufnahmebereich gemäß 3 und 4,
• 7 Trennung des Durchflussbereichs und des/der UV-Strahler mittels einer durchsichtigen Scheibe,
• 8 Trennung des Durchflussbereiches mittels zwei durchsichtigen Scheiben, zwischen denen die UV-Strahler angeordnet sind in der Seitenansicht,
• 9 Schnitt A-A gemäß 8.

They show:

• 1 a device for disinfecting liquid media with a UV lamp in the front view
• 2 the device according to 1 in side view,
• 3 a device for disinfecting liquid media with two UV lamps arranged next to each other in the front view,
• 4 the device according to 3 in side view,
• 5 upper recording area according to 3 and 4 ,
• 6 lower recording area according to 3 and 4 ,
• 7 Separation of the flow area and the UV lamp(s) by means of a transparent pane,
• 8 Separation of the flow area by means of two transparent panes between which the UV lamps are arranged in the side view,
• 9 Section AA according to 8 .

1 shows in front view and 2 in side view, a device with a UV lamp 1, which is designed to extend longitudinally (along a longitudinal axis L) and is accommodated in a transparent element in the form of a glass tube 2. The glass tube 2 is encased in a housing 3, which forms the irradiation chamber and is provided with a head region 4 at its upper end and a foot region 5 at its lower end, wherein the positioning of the glass tube takes place in the foot region and the electrical connection of the UV lamp is realized in the head region 4 and the position positioning is also realized. There is a distance a between the outer circumference 2.1 of the glass tube 2 and the inner wall 3.1 of the housing 3, so that a flow channel 6 is formed for the medium M. The medium M is fed into the irradiation chamber as a flow V at the lower end of the chamber, for example, and exits from the chamber as a return R at the upper end of the chamber, which is shown by the thicker arrows.

Alternatively, the medium can also be introduced via the foot area 5 and discharged via the head area 4.

The housing 3 is here designed in the form of a tube with a square cross-section and has on one side a plurality of ultrasonic elements 7 which are arranged one above the other along the longitudinal axis L and at a distance from one another on one side of the housing 3.

In the 3 and 4 A similar reactor (device) is shown in the front view and in the side view, whereby in contrast to the variant according to the 1 and 2 a rectangular housing 3 is used in which two UV lamps 1 are arranged along the longitudinal axis L, each UV lamp being encased in a glass tube 2. The two glass tubes 2 are arranged next to each other and approximately in the middle on the longer side of the rectangular housing. Ultrasonic elements 7 are also arranged one above the other on the outside of the housing 3 along the longitudinal axis L, here on the longer side. The two glass tubes 2 are arranged parallel to each other and at a distance from each other, whereby the medium can also flow between them.

The glass tubes 2 form protective tubes for the UV lamps 1 and consist in particular of quartz glass.

The medium M flows around the variants according to the 1 and 2 the glass tube(s)/protective tube(s) 2 and is disinfected by the UV light of the UV lamp(s). In 4 the head area of the reactor/device is shown in an enlarged view.

The distance a of the outer surface 2a to the inner wall 3.1 of the protective tube(s) 2 is, for example, 3 to 10 mm, in particular 5 to 8 mm, a distance of 6.5 mm has proven to be particularly advantageous.

The distance b between the glass tubes 2 in the form of the protective tubes is 12 mm to 22 mm, preferably 15 mm to 19 mm, in particular 17 mm.

The inner distance c of the inner surfaces 3.1 of the longer side of the housing 3 is 50 to 100 mm, in particular 65 mm to 90 mm, particularly preferably 70 mm to 80 mm.

The protective tubes / glass tubes 2 are open in the head area 4 in order to 5 shown above) to insert the UV lamp 1.

At this upper end, each protective tube / glass tube 2 is sealed against the reactor body, here against the head part 4, by means of O-rings 8. The head part 4 is in turn connected to the housing 3 in a liquid-tight manner and closed at the upper end with an end plate 9.

The UV lamps 1 are provided with contact areas 1.1 at their upper end and are electrically contacted (not shown),

In 6 an enlarged sectional view of the base area 4 is shown. This shows that the protective tube/glass tube 2 has a round base 2.2 at its lower end, which is inserted into a guide 4.2 of the base part 4, so that the glass tube 2 is fixed. The base part 4 is also connected to the rectangular housing 3 in a liquid-tight manner and is provided with a base plate 10 which closes off at the bottom and is also sealed.

The reactor material for the housing 3 is preferably stainless steel in order to be able to transmit the vibrations of the ultrasonic elements 7 (US oscillators).

In principle, the number of UV lamps 7 and protective tubes / glass tubes 2 can be varied from 1 piece to X pieces.

In 7 A further variant of the solution according to the invention is shown. The UV lamp 1 is separated from the medium by means of a transparent element in the form of a disk 11, which flows through the housing 3 in the chamber arranged here to the right in relation to the disk 11. Several UV lamps 1 can be arranged next to one another and/or one behind the other in the housing 3.

Here, the reactor/device is divided by a disk 11 made of quartz glass.

The quartz glass/disk 11 must be arranged in a sealed manner in the housing 3. On the side of the housing 3 through which the medium M flows, the ultrasonic elements 7 are arranged on the outside of the housing 3.

A further variant of the inventive solution is shown as a schematic diagram in 8 in side view and in 9 in section AA according to 8 shown.

Several UV lamps 7 are arranged next to each other between two disks 11 made of quartz glass. The medium M flows past each disk 11. The forward and return flow are not shown.

The medium M flows past the two panes 11 and is disinfected by means of the UV lamps 1, which shine through the panes.

The dimensions of the UV lamps 7 and protective tubes / glass tubes 2, panes 11 depend on the respective performance class of the UV lamp.

Shorter, longer, thinner and thicker dimensions are also possible.

The geometry of the reactor/device must be adapted accordingly. The number of ultrasonic transducers 7 is also variable.

The arrangement of the ultrasonic elements 7 can be adapted to the geometry of the reactor body/device, for example in several rows.

The ultrasonic elements 7 do not necessarily have to be arranged on just one or two sides of the reactor. The ultrasonic elements could also be distributed all around, depending on the application and which surfaces in the reactor/device need/should be cleaned.

Since the medium M flowing past the glass tubes 2 / protective tubes and the disks 11 can cause deposits on the glass tubes 2 / protective tubes and the disks 11, this would impair the penetration of the UV rays and thus impair the cleaning performance or disinfection effect on the medium M.

The use of the ultrasonic elements 1 ensures for the first time that the ultrasonic vibrations acting on the transparent element(s) in the form of the protective tubes/glass tubes 2 or disks 11 2/11 via the housing 3 and the medium M remove existing deposits from these or prevent the formation of deposits. Furthermore, deposits on the housing are removed.

The flow direction in the reactor/device should be from bottom to top.

In the variants according to the 1 to 4 The connection for the medium can also be made in the middle from below. The outlet should be on the top right-hand side.

In general, however, the forward and return flow can also be designed differently or flexibly.

Reactor geometry, distances, number of UV lamps 1, number of ultrasonic elements 7, etc. can be implemented flexibly and adapted to the application. If necessary, the most suitable configuration can also be determined through preliminary tests.

In order to prevent mutual interference between the ultrasonic elements, specific minimum distances between the ultrasonic elements must be observed depending on the type.

By disinfecting the medium, the health burden on employees can be reduced and unpleasant odors can be reduced.

Overall, the service life of the medium is extended. This reduces running costs and downtime for machines and operators.

This is achieved by reducing or preventing the growth of microbial contamination in the cooling lubricant (CL), if this is the medium to be cleaned, through the continuous use of UVC radiation during the running time of the machines.

For this purpose, the coolant is pumped from the storage tank of the machine tool through at least one irradiation chamber of the device. When passing through the irradiation chamber, the coolant is exposed to UVC light and thus disinfected. Previous studies have shown a significant reduction in the number of germs in coolant that has already become sooty. In addition, the smell was noticeably reduced and rashes on the employees' skin decreased or no longer occurred.

The additional use of ultrasonic elements prevents the settling of suspended matter, fats and foreign oils on the transparent elements.

For this purpose, the ultrasound elements are mounted on the outside of the device's irradiation chamber and act on the inside of the chamber. Adhesions to the transparent elements/glass are removed by the cavitation generated and the effectiveness of the UV radiation is restored or not restricted.

The system is designed for permanent installation directly on a machine or on a nearby frame or wall, for example if coolant needs to be disinfected. A pump mounted on the coolant storage tank continuously pumps the machine's cooling lubricant through the disinfector.

The flow rate of the coolant is defined by the performance of the pump. Depending on the size of the storage tank, the UVC output can be adjusted by selecting the UVC lamps in advance to ensure sufficient disinfection.

The system is operated by an implemented control system that can be operated via a touch display. The operator can use it to set the frequency of the system's cleaning cycles with ultrasound as well as the system's running time for UVC disinfection.

The system then runs autonomously according to the set specifications. The operator should then only need to provide support at the necessary maintenance times for the system. Maintenance is then limited to replacing the UVC lamps, which is usually carried out once a year after the operating hours specified by the UVC lamp manufacturer, i.e. in the case of 24/7 operation.

By setting up the system with, for example, two UVC lamps, it is possible to replace one of the two UVC lamps, which generate UVC light with a wavelength of 254nm, with a UVC lamp that generates UVC light with a wavelength of, for example, 185nm.

The wavelength of 254nm is used for pure disinfection within the UVC chamber. The wavelength of 185nm, on the other hand, generates additional ozone or free radicals in the cooling lubricant. These radicals are carried out of the UVC chamber with the cooling lubricant and ensure additional disinfection in the pipes and storage tank.

The device should be able to run autonomously thanks to the ultrasonic elements, thus ensuring optimal and energy-saving UVC disinfection. This should reduce the maintenance effort required by the operator to a minimum. Depending on the size and performance of the system, the running costs in the maintenance cycle are reduced to the power consumption and are, for example, only between 0.10 kWh and 0.5 kWh.

list of reference symbols

1

UV lamps

1.1

contact area

2

glass tube

2.1

outer circumference

2.2

round bottom

3

Housing

3.1

interior wall

4

head area

5

foot area

6

flow channel

7

ultrasonic element

8

O-ring

9

end plate

10

base plate

11

disc

12

protective tube

L

longitudinal axis

M

medium

R

return

V

lead time

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• DD 255 358 A1 [0008]
• WO 2012/219243 A1 [0009]

Claims (10)

Device for disinfecting liquid media, wherein the liquid medium is exposed to UV rays in a continuous process by means of at least one UV lamp and the UV lamp is separated from the medium flowing past by means of at least one transparent element, characterized in that the device has at least one ultrasonic element which exposes at least the transparent element to ultrasonic vibrations. device according to claim 1 , characterized in that it has at least one irradiation chamber with at least one channel through which the medium flows and that one or more UV lamps are arranged in the chamber, which are separated from the medium by the transparent element and that at least one ultrasonic element is arranged on an outer wall of the chamber, the vibrations of which prevent or remove deposits on a surface of the transparent element past which the medium flows. device according to claim 1 or 2 , characterized in that the irradiation chamber is formed from a hollow profile with a polygonal cross-section, in particular a rectangular or square one. Device according to one of the preceding claims, characterized in that at least one or more UV emitters extending along a longitudinal axis of the hollow profile are arranged in the hollow profile and that the UV emitter(s) are encased in a glass tube around which the medium flows and/or that a transparent liquid-tight partition is arranged between the UV emitter(s) and the medium and that on the outer wall of the chamber in relation to the longitudinal axis a plurality of ultrasonic elements are arranged one above the other and/or next to one another. Device according to one of the preceding claims, characterized in that a supply line and a discharge line for the medium lead into the irradiation chamber. Device according to one of the preceding claims, characterized in that the medium is a cooling-lubricating liquid of a machine tool and that the supply line and the discharge line are connected to a container of the cooling-lubricating liquid and that the medium is circulated by means of a pump from the container through the irradiation chamber and back into the container. Device according to one of the preceding claims, characterized in that the transparent element consists of quartz glass. Device according to one of the preceding claims, characterized in that the UV emitters are UVC emitters and that in particular two types of UVC emitters are present, wherein a first type of UVC emitter generates UVC light with a wavelength of 254 nm and a second type of UVC emitter generates UVC light with a wavelength of 185 nm. Method for disinfecting liquid media, with a device according to claim 1 , wherein the liquid medium is exposed to UV rays in the continuous process by means of at least one UV lamp and the UV lamp is separated from the medium flowing past by means of at least one transparent element and the liquid medium is exposed to the UV rays through the transparent element, characterized in that during the continuous process ultrasonic vibrations are generated by means of at least one ultrasonic element, which prevent the formation of deposits at least on the transparent element and/or remove existing deposits. procedure according to claim 9 , characterized in that the ultrasonic vibrations act permanently during the disinfection process or that the ultrasonic vibrations are generated at fixed intervals.

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