JP4752998B2 - Retort pressure control method and support system for containers with pressure absorption capability - Google Patents

Description

  The present invention relates to rational pressure control in a retort sterilization treatment of a plastic sealed container provided with a pressure absorbing panel (negative pressure / positive pressure absorption).

  Many sealed containers filled with food enable long-term quality maintenance by heat sterilization after refilling in a retort kettle. Sterilization in a retort kettle is often a batch-type beverage, that is, a batch type, that is, sealed containers are closely arranged in a basket and stored in a multi-layered state. The container is heated and sterilized by circulating hot water (hereinafter referred to as a heating medium) and bringing it into contact. The heat sterilization in the retort kettle is performed by heating from room temperature, maintaining a high temperature for a predetermined time, and then cooling to return to room temperature. The inside of the container is not only filled with contents, but also gas is present in a portion called a head space (hereinafter abbreviated as HS). When the container is heated, the container itself, the contents, and the gas are thermally expanded. In particular, gas is greatly affected by heat change, which acts as an internal pressure of the container. Therefore, conventionally, so-called isobaric control is performed in which the internal pressure of the container is calculated from the internal temperature of the tank using the Boyle's law, and the internal pressure of the tank is controlled so that a pressure corresponding to the pressure is applied to the outer surface of the container.

  However, the calculation formula of the internal pressure of the container is only for the thermal change of the amount of the enclosed gas, and the thermal expansion of the contents (liquid) is not included in the element, the effect of the HS amount at the time of filling, the pressure absorption part (panel And the influence of the lid is not included in the calculation factor. Therefore, the difference between the actual container internal pressure value and the calculated value is large, and there is a high risk of causing an appearance defect that causes deformation of the container. When a plastic container is sterilized by retort, the rigidity is low at the glass transition point or higher, and it is unlikely to be compared with a metal can. Therefore, if a pressure difference occurs between the inside and outside of the container, the plastic container is easily permanently deformed. As a means for absorbing this pressure difference, the cup container has an uneven shape on the lid and bottom, or in the case of a bottle, a pressure absorbing panel having an uneven shape formed on the body is provided (Patent Document 1, 2). However, since the differential pressure absorbing capacity is not large at all, when the cup container is sterilized by retort, the pressure pattern in the tank is set by equal pressure control so as not to give a pressure difference to the container.

  Further, in the above container internal pressure calculation, since the product temperature of the contents is calculated as being equal to the tank internal temperature, an error from the actual internal pressure is generated, which also increases the risk of causing an appearance defect. . In order to reduce this error, the temperature gradient at the time of temperature rise and cooling is relaxed, that is, the temperature rise time and the cooling time are set longer, and the difference between the product temperature of the contents and the temperature in the tank is reduced. There was a need. Patent Document 3 is proposed as a solution to this problem. This invention measures the gas phase temperature, the surface temperature of the liquid phase portion, and the liquid bottom temperature of the liquid phase portion for the liquid in the aerated container to be sterilized by heating housed in the retort sterilizer, The gas partial pressure is calculated from the gas phase temperature, the saturated vapor pressure is calculated from the liquid surface temperature, the pressure due to liquid expansion is calculated from the average temperature of the liquid surface temperature and the liquid bottom temperature, and the internal pressure of the aerated container is calculated. This is a pressure control method for controlling the pressure in the tank of the retort sterilizer. Since the present invention uses the thermal expansion, HS temperature, and product temperature of the content liquid as calculation elements, it has the effect that the error from the actual container internal pressure is relatively small, but the effect of the HS amount during filling, the pressure absorption of the container Since the influence of the part is not included in the calculation element, there is a problem that there is a high risk of causing a poor appearance of the container unless more precise pressure control is performed.

  Patent Document 4 discloses a method for controlling the isobaric pressure by calculating the product temperature of the content liquid from the temperature in the tank using a sequential heat transfer calculation formula. That is, in the retort process of temperature rise, constant heating, and cooling treatment, using the sequential heat transfer calculation formula, the temperature of the moisture in the aerated container is obtained from the temperature in the tank, and the pressure in the aerated container is derived. Based on this, a retort processing method for a sealed container product in an aerated form in which the pressure control of the retort processing is performed was performed. In this method, the temperature of the moisture in the aerated container, that is, the product temperature is obtained, and the container internal pressure is calculated based on the value. Therefore, the error from the actual container internal pressure is reduced, and the risk of poor appearance due to this is reduced. It became low. Further, since the calculation is based on the product temperature, there is no need to reduce the difference from the temperature in the tank, and there is an effect that the heating time and the cooling time can be set short. However, even in this invention, the calculation formula of the container internal pressure is only for the heat change of the amount of the enclosed gas, the thermal expansion of the contents (liquid), the effect of the HS amount during filling, the effect of the pressure absorption part (panel or lid) Is the same as the conventional one in that it is not included in the calculation element, and has a problem that the difference between the actual container internal pressure value is large and there is a high risk of causing an appearance defect that causes deformation of the container.

Under such circumstances, the pressure pattern setting of the conventional isobaric control is that the person in the tank changes the unevenness of the cup lid material or the deformation of the pressure absorption panel of the bottle for each product in the retorting process of temperature rise → constant heating → cooling. This requires a time-consuming work of manually setting an optimum pressure pattern while observing the above. In addition, the calculation of the internal pressure of the container used for the isobaric control is based on the condition that the volume of the contents does not change (no thermal expansion), so the relationship between the HS amount and the internal pressure of the container is not captured. Have a problem.
Japanese National Publication No. 6-500979 “High Panel Strength Retort Plastic Container” Published on February 3, 1994 Special table 2004-519394 gazette "Retortable plastic container" July 2, 2004 publication Japanese Patent Laid-Open No. 4-20276 “Method of controlling pressure during heat sterilization of liquid processed product in aerated container” Published on January 23, 1992 Japanese Patent Laid-Open No. 2001-54375 “Retort Processing Method for Air-Contained Sealed Container Product” Published on February 27, 2001

  In the case of retorting a plastic container, the setting of the pressure pattern of the isobaric control is that the optimum pressure pattern is manually set while observing the deformation of the container, and the problem to be solved by the present invention is Retort capable of automatic control by calculating the pressure control range that does not cause permanent deformation of the container, taking into account the ability to calculate the internal pressure of the container more precisely and also taking into account the absorption capacity of the pressure absorption part of the container To realize the pressure control of the pot and to provide a support system for it, to keep the pressure in the pot at the time of sterilization as low as possible, and to reduce the equipment cost by reducing the number of pressure pattern setting steps is there.

The retort pressure control method of the present invention uses a plastic container in which a pressure absorption panel having a pressure absorption capacity of 0.5% or more and 5.0% or less is applied to at least a part of a body portion, and the capacity of the capacity that is in a panel negative pressure absorption state during retort. a controls the pressure in the retort kiln within range of the pressure for the capacitive maximum in the internal pressure of the retort of the small time upper limit pressure of the pressure control, the panel positive pressure absorbing state and the lower limit pressure, the panel negative pressure absorption The internal pressure value at the minimum capacity in the state and the internal pressure value at the maximum capacity in the panel positive pressure absorption state are the filling conditions including the filling temperature, head space (HS) amount, and the amount of enclosed gas , and the minimum capacity The set internal pressure value of Y is a negative value Y, and the set internal pressure value at the maximum capacity is calculated using the pressure value P (unit MPa) calculated by the equation (a) using the positive value Y. I asked for it.
P = Pa + Pw−0.1
= 0.098 × (1.03 × T × X × Z) ÷ 293 {D × X + Y + 100 (1-D)}
＋ Pw−0.1 ‥‥‥‥‥‥ (a)
Here, Pa: head space gas pressure, Pw: saturated water vapor pressure, and both units are MPa.
T: Retort temperature (unit: K)
D: D = Dtl / Dt2 (Dtl: specific gravity of the liquid at the filling temperature, Dt2: specific gravity of the liquid at the retort temperature T)
X:% of the head space (HS) immediately after filling in the bottle capacity
Y: Percentage of pressure absorption capacity in bottle capacity (positive pressure absorption Y> 0, negative pressure absorption Y <0)
Z: The ratio of HS to the amount of enclosed gas A Z = A / HS
In the formula, 0.1 is atmospheric pressure and is used to adjust the P value to the gauge pressure value.
Further, the retort pressure control method of the present invention calculates the amount of heat shrinkage of the container by setting the ratio Y of the pressure absorption capacity of the formula (a) in the bottle capacity to a value obtained by subtracting the amount of heat shrinkage during retort sterilization. I took it into.

The method for filling a container for retort sterilization according to the present invention is a filling condition (filling temperature, HS) that is within the range of an appropriate pressure pattern with respect to the pressure in the retort kettle, the pressure absorption capacity of the container, and the temperature pattern of retort sterilization. A table in which the amount and the amount of enclosed gas) were calculated based on the formula (a) was prepared, and the filling conditions were selected based on the table.
The pressure control support system in a retort kettle according to the present invention comprises an input means, a storage means, a computing means and a display, and inputs data relating to a container including a pressure absorption capacity, filling conditions and specifies a temperature pattern in the kettle. When necessary information is input to this table by displaying a data input list on the display and inputting values in the corresponding fields using the input means, the calculation means is based on the equation (a) stored in the storage means. It has a function of executing calculation and calculating an upper limit pressure value and a lower limit pressure value.
Furthermore, along with the calculated upper limit pressure value and lower limit pressure value curve, the temperature in the retort kettle, the actual product temperature value, and the pressure value pattern for constant capacity control are displayed on the display on the graph display screen along the time axis, If an appropriate pressure value is plotted between the upper limit pressure value and the lower limit pressure value on this display screen, a control pattern that connects the points with a curve or a straight line can be specified.
Further, the pressure absorption capacity design support system for a container for retort sterilization according to the present invention comprises an input means, a storage means, a calculation means, and a display. The storage means stores the formula (a), and is input by the input means. Calculate the required pressure absorption capacity based on the formula (a) based on the formula (a) on the basis of the filling conditions including the upper limit pressure and lower limit pressure set value in the retort pot and the filling temperature, HS amount, and the amount of enclosed gas. And the result is displayed on the display.

Since the retort pressure control method of the present invention actively utilizes the pressure absorption capability of a plastic container having a pressure absorption panel applied to at least a part of the body, it is possible to keep the pressure in the pot during sterilization low. And the cost of equipment can be reduced. In addition, the amount of HS can be reduced, and the amount can be set to the same level as the amount of gas enclosed in the hot pack product. Specifically, in order to control the internal pressure at the time of the minimum capacity in the panel negative pressure absorption state within the range of the upper limit pressure of the pressure control and the pressure at the maximum capacity in the panel positive pressure absorption state to the lower limit pressure, Thus, it is no longer necessary to manually set the optimum pressure pattern while observing the deformation of the container, and operation by automatic control becomes possible. Further, the width of the pressure pattern that does not cause permanent deformation of the container is widened, and the number of steps for setting the pressure pattern can be reduced.
In addition, the retort pressure control method of the present invention includes the internal pressure value of the retort kettle at the time of the minimum capacity in the panel negative pressure absorption state and the internal pressure value at the maximum capacity in the panel positive pressure absorption state at the filling temperature, HS Because it is obtained by precise calculation with the filling condition including the amount and the amount of sealed gas as an element, the appropriate pressure control width can be quantified, and automatic control that does not require human observation can be performed accurately. it can.
By setting the ratio Y of the pressure absorption capacity of the formula (a) in the bottle capacity to a value obtained by subtracting the amount of heat shrinkage during retort sterilization, more precise calculation that incorporates the amount of heat shrinkage of the container into the calculation element was realized.

The method for filling a container for retort sterilization according to the present invention is a filling condition (filling temperature, HS) that is within the range of an appropriate pressure pattern with respect to the pressure in the retort kettle, the pressure absorption capacity of the container, and the temperature pattern of retort sterilization. By preparing a table in which the amount and the amount of enclosed gas) are calculated based on the formula (a) in advance, the filling conditions can be easily selected based on the table.
The pressure control support device in the retort kettle according to the present invention is simple in that data relating to a container including a pressure absorption capacity and a filling condition are entered on a data input list displayed on a display and a temperature pattern in the kettle is specified. Since it has a function to calculate the upper limit pressure value and the lower limit pressure value by performing an operation based on the arithmetic expression stored in the storage means simply by performing a simple operation, it is easy even for a skilled engineer. Necessary data can be acquired.
Furthermore, together with the calculated upper limit pressure value and lower limit pressure value curve, the retort kettle temperature, the actual product temperature measurement value, and the constant value control pressure value pattern are displayed on the display on the graph display screen along the time axis, If a suitable pressure value is plotted between the upper limit pressure value and the lower limit pressure value on this display screen, it has a function that can specify a control pattern that connects the points with a curve or a straight line. Even if it is not, the retort pressure control pattern can be set easily.
Further, the pressure absorption capacity design support system for a container for retort sterilization according to the present invention comprises an input means, a storage means, a calculation means, and a display. The storage means stores the formula (a), and is input by the input means. Calculate the required pressure absorption capacity based on the formula (a) based on the formula (a) on the basis of the filling conditions including the upper limit pressure and lower limit pressure set value in the retort pot and the filling temperature, HS amount, and the amount of enclosed gas. And since it has the function to display the result on the said display, the pressure absorption capacity of the container to be used can be designed easily.

As a basis for deriving the present invention, details of a formula for calculating a bottle internal pressure during retort will be described first.
When the capacity of the empty bottle before filling is Vc, the filling temperature T1, the headspace gas partial pressure P1, and the HS amount V1 are X% of Vc,
V1 = Vc × X ÷ 100, filling capacity VL1 is VL1 = (1−X ÷ 100) × Vc
The filling weight B is represented by B = (1−X ÷ 100) Vc × Dt1.
Here, Dt1 is the specific gravity of the content liquid at the filling temperature T1.
First, assuming that the headspace during retort sterilization is V2, the content liquid volume is VL2, the container volume is assumed to be a constant value Vc during retort sterilization, and the headspace temperature during retort sterilization is assumed to be the retort temperature, retort sterilization The internal pressure P2 of the gas when the temperature is T2 is, according to Boyle's law,
P2 = (P1 × V1 × T2) ÷ (T1 × V2) (1)
In addition, since V2 = Vc−VL2,
V2 = Vc−B ÷ Dt2 = Vc− (1−X ÷ 100) Vc × Dt1 ÷ Dt2
= {1− (1−X ÷ 100) Dt1 ÷ Dt2} × Vc,
Here, Dt2 is the specific gravity of the content liquid when the retort sterilization temperature is T2. If D = Dt1 / Dt2,
V2 = (X × D ÷ 100 + 1−D) × Vc (2)
From equations (1) and (2),
P2 = (T2 × P1 × V1) ÷ {T1 × Vc × (X × D ÷ 100 + 1−D)} (3)
Assuming that the headspace gas partial pressure of the 20 ° C. container after filling and cooling is P3, the HS amount is V3, and the enclosed gas amount is A, according to Boyle's law,
(P1 × V1) ÷ T1 = (P3 × V3) ÷ 293 = 0.098 × 1.03 × A ÷ 293
The gas pressure became atmospheric pressure when it returned to room temperature of 20 ° C., and this was expressed in MPa.
P1 x V1 = 0.098 x 1.03 x A x T1 ÷ 293 (4)
From equations (3) and (4),
P2 = (0.098 × 1.03 × T2 × A × T1 ÷ 293) ÷ {T1 × Vc × (X × D ÷ 100 + 1−D)}
= (0.098 × 1.03 × T2 × A ÷ 293) ÷ {Vc × (X × D ÷ 100 + 1−D)}
If Z = A ÷ V1, then A = X × Z × Vc ÷ 100, so P2 = {(0.098 × 1.03 × T2 × X × Z × Vc) ÷ (100 × 293)) ÷ {Vc × ( X × D ÷ 100 + 1−D)} = (0.098 × 1.03 × T2 × X × Z) ÷ 293 {D × X + 100 (1-D)}
Is guided.

表中＊印となっているところは測定限界値0.5ＭPaを越えたものである。この表から確認できるように吸収能力が高ほど内圧上昇が抑制されており、0.5％以下のものでは１２５℃では測定限界値0.5ＭPaを越えてしまう。 Next, various phenomena affecting the sealed container during the retort sterilization process will be discussed.
If the pressure absorption panel has a positive pressure absorption capability, the panel during heat sterilization will be in a convex state, the amount of HS will increase, and the pressure rise in the bottle will be reduced. As a result, the pressure in the retort pot can be reduced, and the cost of the pressurizing equipment is reduced. Therefore, the degree of the positive pressure absorption capacity and the internal pressure value in the container were compared and measured. The results are shown in Table 1. This data is prepared for 5 types of containers with absorption capacity of 0%, 0.1%, 0.5%, 1%, 3%, filling temperature of the contents liquid is 85 ° C, HS amount is 3% of container volume, and amount of filled gas The sample was filled and sealed under the condition where the ratio of the HS amount was 0.6, and measured at temperatures of 115 ° C., 120 ° C., and 125 ° C. In the present invention, the head space (HS) amount is obtained from the filling amount. The amount of the enclosed gas is determined from the gas partial pressure in the head space.

Those marked with * in the table are those exceeding the measurement limit of 0.5 MPa. As can be confirmed from this table, the increase in internal pressure is suppressed as the absorption capacity is higher. If the absorption capacity is 0.5% or less, the measurement limit value 0.5 MPa is exceeded at 125 ° C.

この結果から、ＨＳ量は少ないほど加熱殺菌時の容器内圧が高くなること、しかし、吸収能力が高ければその内圧上昇を抑えることが出来ることが分かる。非圧縮性流体である内容液の熱膨張分は圧力吸収パネルの吸収能力でカバーできることにより、ＨＳ量をホットパック充填品と同等（３％以下）の充填条件で行ってレトルト殺菌が可能となる。 Next, Table 2 shows the results of an experiment for verifying the effect of changing the HS amount. This data consists of 4 types of containers with positive pressure absorption capacity of 1%, 1.5%, 3% and 5%, the filling temperature of the contents liquid is 85 ° C, the ratio of the amount of sealed gas and HS is 0.6, and the amount of HS Was filled and sealed as 0.1%, 1%, 2%, 3%, 4%, 5%, and 10% of the container volume, and measured at a temperature of 125 ° C.

From this result, it can be seen that the smaller the amount of HS, the higher the internal pressure of the container during heat sterilization, but the higher the absorption capacity, the higher the internal pressure can be suppressed. Since the thermal expansion of the content liquid, which is an incompressible fluid, can be covered by the absorption capacity of the pressure absorption panel, retort sterilization is possible by performing the HS amount under the same filling condition as the hot pack filling (less than 3%). .

表中で○印は外観に変形がなかったもの、×印は外観に肩部変形や底バックリングといった変形が認められた容器である。圧力吸収能力を持たない容器ではいずれの場合のものも外観変形をきたすものが生じ、圧力吸収能力が−1.5％のものでは充填温度が２℃だけのバラツキの幅の方は変形しなかったが５℃バラツキを持ったものでは変形が認められた。また、−３％の圧力吸収能力を有する容器では充填温度が２℃のバラツキだけでなく５℃のバラツキを持ったものでも変形しなかった。充填温度、ＨＳ量、封入ガス量とＨＳ量の比といった充填条件を適正に設定することで、内容液の熱膨張の影響を低くし、温度の高い殺菌工程でのＨＳ量を大きくし、封入ガス密度低くできるので、レトルト釜内圧力を小さくでき、加圧設備のコストを低く抑えることが出来る。
なお、本明細書では、圧力吸収能（Ｙ％）は、容器の外観の不良を起こさない範囲においてまず、２０℃の水を容器に満注充填した状態にして、２０℃の水を注入器により更に注入できる量Ｘを測定する。また、上記満注充填した状態において吸引器を用いて吸引できる体積Ｘを測定する。その結果から下式により求めるものとする。
圧力吸収能（Ｙ％）＝（Ｘ÷Ｖｃ）×１００
但し、ここでＶｃは容器容量である。 Next, the negative pressure absorption action of the pressure absorption panel will be considered. In the retort sterilization process, the sealed container receives a temperature change of heating temperature rise → constant heating → cooling and a pressure change from the ambient atmosphere. In the process, the container will be in a positive pressure state or a negative pressure state depending on the situation, and will be in a negative pressure state when the pressure in the retort pot exceeds the container internal pressure. The fact that the pressure absorption panel has negative pressure absorption capability, as well as positive pressure absorption capability, gives the pressure pattern in the isobaric control a permissible range, and the container internal pressure due to variations in filling conditions, container manufacture, product temperature, etc. Appearance defects can be prevented even with respect to the difference.
Prepare a container with no pressure absorption capacity and a container with pressure absorption capacity of -1.5% and -3%. Filling conditions are a filling temperature of 85 ° C, an HS amount of 3%, and a ratio of the enclosed gas amount to the HS amount of 0.6. Then, the retort sterilization treatment was performed by heating in a hot water shower for 20 minutes, sterilization at 125 ° C. for 30 minutes, and cooling time of 20 minutes. At this time, the container appearance after retorting was observed with variations in filling conditions and product temperature. The variation in HS amount is ± 10%, the variation in container capacity is ± 1.5%, the variation in product temperature is ± 20 ° C, and each container has a filling temperature of ± 2 ° C and ± 5 ° C. Some were tested. The results are shown in Table 3.

In the table, a circle mark indicates that the outer appearance was not deformed, and a cross mark indicates that the outer shape is deformed such as shoulder deformation or bottom buckling. In the case of a container that does not have pressure absorption capability, there was a change in appearance in any case, and when the pressure absorption capability was -1.5%, the variation width of the filling temperature of only 2 ° C did not deform. Deformation was observed in those having a 5 ° C. variation. Further, in the container having a pressure absorbing ability of −3%, even when the filling temperature was not only 2 ° C. variation but also 5 ° C. variation, it was not deformed. By properly setting the filling conditions such as the filling temperature, the amount of HS, and the ratio of the amount of sealed gas to the amount of HS, the effect of the thermal expansion of the content liquid is reduced, the amount of HS in the high temperature sterilization process is increased, and sealing is performed. Since the gas density can be lowered, the pressure in the retort kettle can be reduced, and the cost of the pressurizing equipment can be kept low.
In the present specification, the pressure absorption capacity (Y%) is set within a range in which the appearance of the container is not deteriorated. First, the container is filled with 20 ° C. water, and 20 ° C. water is injected into the container. The amount X that can be further injected is measured. Further, the volume X that can be sucked using the suction device in the fully filled state is measured. From the result, it shall be obtained by the following formula.
Pressure absorption capacity (Y%) = (X ÷ Vc) × 100
Here, Vc is a container capacity.

当然のことながら充填温度は高いほど、ＨＳ量は大きいほど、そして封入ガス量とＨＳ量の比は低いほど設備圧力は低くてよいことになる。 Next, lower limit that does not cause poor appearance of the container by using a container with 2% pressure absorption capacity at the time of container expansion, and performing retort sterilization with hot water shower for 20 minutes, 125 ° C for 30 minutes, and 20 minutes for cooling. The retort kettle pressure was tested by changing the filling conditions. The filling conditions are first set to 65 ° C and 85 ° C for the filling temperature, 2% and 3% for the HS amount, respectively, and the ratio of the enclosed gas amount to the HS amount is set to three types of 0.8, 0.6 and 0.4. Experimented with a combination of. The results were as shown in Table 4.

As a matter of course, the higher the filling temperature, the larger the HS amount, and the lower the ratio of the enclosed gas amount and the HS amount, the lower the equipment pressure.

  Next, the relationship between the HS amount and the container internal pressure in a container having a pressure absorption capability will be shown. That is, the filling temperature is set to 85 ° C in four types of containers with pressure absorption capacity of 0%, 0.5%, 2% and 3%, and the ratio Z (A / HS) of HS and the amount of gas A is set to 0.6. The ratio D of the specific gravity between the temperature content liquid and the retort temperature content liquid is 1.03 at 125 ° C, 1.01 at 100 ° C, and the saturated vapor pressure is 0.23 at 125 ° C and 0.10 at 100 ° C. The container internal pressure value obtained by calculation with respect to the HS amount is shown in the graph of FIG. In the figure, A is the value when it is brought to the sterilization temperature of 125 ° C, and if it is 3% of the standard HS amount, if the container has an expansion panel capacity of 2% or more, the inner pressure of the bottle is caused by the convex deformation of the container. Is within 0.3MPa. In addition, the graph shown in B of the figure is the value when cooled from 125 ℃ sterilization temperature and brought to 100 ℃, but even if the inside of the container becomes a negative pressure due to cooling, the container having the pressure absorption capacity is concavely deformed The internal pressure is 0.5 MPa or more, indicating that it does not decrease. In other words, it has been shown that a container having a pressure absorbing capability hardly causes permanent deformation.

In consideration of the various phenomena discussed above, the present invention pays attention to the fact that the allowable pressure differential width is widened by this pressure absorption capability, and takes into account the change in internal pressure that accompanies the change in volume of the container due to the action of the pressure absorption panel. It was to be. Therefore, the change in internal pressure when the container capacity is assumed to expand or contract Y% of Vc during retort sterilization (expansion Y> 0, contraction Y <0) will be considered. In this case, the container capacity in the retort is represented by (1 + Y ÷ 100) Vc, and the HS amount V2 during the retort sterilization is represented by the following equation.
V2 = (1 + Y ÷ 100) Vc−VL2 = (1 + Y ÷ 100) Vc−B ÷ Dt2
= (1 + Y ÷ 100) Vc− (1−X ÷ 100) Vc × Dt1 ÷ Dt2
= (X × D ÷ 100 + Y ÷ 100 + 1−D) Vc (5)
From the equations (1) and (5), the container internal pressure P2 in the retort is expressed by the following equation.
P2 = (T2 × P1 × V1) ÷ {T1 × Vc × (X × D ÷ 100 + Y ÷ 100 + 1−D)} (6)
From equations (4) and (6),
P2 = (0.098 × 1.03 × T2 × X × Z) ÷ 293 {D × X + Y + 100 (1-D)}
= 0.098 × (1.03 × T2 × X × Z) ÷ 293 {D × X + Y + 100 (1-D)} (7)
Is derived.

The limit value at which the container is not permanently deformed by the internal / external differential pressure corresponds to the pressure absorption capacity. Therefore, if the atmospheric pressure is controlled between the expansion limit and the compression limit of the container, there is no problem as an equal pressure control. . Therefore, in the retort sterilization method of the present invention, the set internal pressure at the minimum capacity corresponding to the compression limit and the set internal pressure at the maximum capacity corresponding to the expansion limit are calculated based on the equation (7). To control. The Y value in the former case is negative, and the Y value in the latter case is a positive number. The pressure value P (unit MPa) calculated by the equation (7) is used.
P = Pa + Pw−0.1
= 0.098 × (1.03 × T × X × Z) ÷ 293 {D × X + Y + 100 (1-D)} + Pw−0.1
‥‥‥‥‥‥ (a)
Here, Pa: gas pressure, Pw: saturated water vapor pressure (unit is MPa)
T: Retort temperature (unit: K)
D: D = Dtl / Dt2 (Dtl: specific gravity of the content liquid at the filling temperature, Dt2: specific gravity of the content liquid at the retort temperature)
X:% of the head space immediately after filling (hereinafter referred to as HS) in the bottle capacity
Y: Percentage of pressure absorption capacity in bottle capacity (positive pressure absorption Y> 0, negative pressure absorption Y <0)
Z: The ratio of HS to the amount of enclosed gas A Z = A / HS
In the formula, “0.1” is atmospheric pressure and is used to adjust the P value to the gauge pressure value.

  Now, a container with pressure absorption capacity of 2% for expansion and compression is filled and sealed with 85 ° C. content liquid in a state of 3% HS, and the temperature inside the retort kettle is raised from room temperature to 100 ° C. over 10 minutes. In the next 10 minutes, the temperature is raised to 125 ° C., sterilized by maintaining 125 ° C. for 30 minutes, and returned to room temperature over 20 minutes. FIG. 2A is a graph showing the result of analyzing the product temperature data based on the pressure control by the method of the present invention. First, in the figure, the line marked with ● is the temperature inside the retort kettle, and the line marked with ◎ is the actual measured product temperature. In the figure, the line marked with ○ is the temperature data in the pot based on the conventional isobaric control, and the triangle is the product temperature data based on the conventional isobaric control. The lower limit pressure value and the upper limit pressure value were calculated by formula (a) according to the analysis method of the present invention considering the pressure absorption capacity of the container, and entered in the graph. In the figure, the lower limit pressure value is the line marked with ☆ and the line marked with the upper limit pressure value ★. As can be seen from this graph, the pressure value by the conventional isobaric control based on the temperature data in the tank indicated by the line marked with ○ and the pressure value by the conventional isobaric control based on the product temperature data indicated by the △ mark are both It can be seen that both have fallen below the lower pressure limit during the sterilization period. That is, in this state, a permanent deformation is left in the container, and automatic control cannot be performed. Therefore, conventionally, a person manually adjusts the pressure while observing deformation of the container.

  In the same way, a container with pressure absorption capacity of 2% for expansion and compression is filled and sealed with 85 ° C content liquid in an HS amount of 5%, and the temperature in the retort kettle is raised from room temperature to 100 ° C over 10 minutes. In the next 10 minutes, the temperature is raised to 125 ° C., kept at 125 ° C. for 30 minutes and sterilized, and then returned to room temperature over 20 minutes. FIG. 2B is a graph showing an analysis of conventional isobaric control based on temperature data using the technique of the present invention. This is an example in which the HS amount is increased from 3% to 5%. In this case, both the pressure value based on the conventional isobaric control based on the temperature data in the tank indicated by the circle mark and the pressure value based on the conventional isobaric control based on the product temperature data indicated by the △ mark are both sterilized. Since it is almost equal to the lower limit pressure value in the middle, it can be seen that even if automatic control is performed, no major problem occurs. That is, it can be seen that automatic control is possible even if control is performed by the conventional method if the HS amount value is increased to 5%.

The method for determining the pressure control signal in the retort sterilization treatment of the present invention is as follows: data on the container such as the capacity (ml) of the container to be used, pressure absorption capacity (%), filling temperature (° C.), HS amount (ml), amount of enclosed gas The upper limit pressure value and the lower limit pressure value are calculated based on the equation (a) by setting the temperature and time of temperature rise → sterilization → cooling as filling conditions such as (ml) and the temperature condition in the pot. From this calculation result, if the range between the upper limit pressure value and the lower limit pressure value is adopted as a control value, retort sterilization without causing external deformation can be performed. However, since the data and filling conditions related to the container are accompanied by a large or small variation, the calculation between the upper limit pressure value and the lower limit pressure value becomes narrower by that amount. If the pressure control is performed in a state slightly exceeding the lower limit pressure value that is the allowable expansion limit of the container, the pressure in the retort kettle can be kept small.
Fill a container with a pressure absorption capacity of 2% at 85 ° C with a 3% HS content and a ratio of filled gas to HS of 0.6, and increase the temperature in the retort kettle from room temperature to 100 ° C over 10 minutes. In the next 10 minutes, the temperature is raised to 125 ° C., sterilized by keeping the temperature at 125 ° C. for 30 minutes, and is subjected to a retort treatment for returning to room temperature over 20 minutes. FIG. 3 shows a graph of the pressure signal value calculated when the original isobaric control is performed. Thus, the constant pressure indicated by the line marked with □ takes approximately the median value of the upper limit pressure value indicated by ◎ and the lower limit pressure indicated by the line marked Δ. If this value is adopted, the safety factor will be high even with respect to variations in each setting data, but since the setting is considerably higher than the lower limit of pressure, the equipment must be able to produce high pressure accordingly. .

  Fill the vessel with 3% pressure absorption capacity with 85 ° C content liquid with 3% HS amount and 0.6 ratio of enclosed gas amount and HS amount and raise the temperature in the retort kettle from room temperature to 100 ° C over 10 minutes In the next 10 minutes, the temperature is raised to 115 ° C., kept at 15 ° C. for 30 minutes for sterilization, and then retorted to return to room temperature over 20 minutes. FIG. 4 shows a calculation of the pressure signal value when performing, and a graph showing a constant pressure pattern. In this case as well, the capacity-invariant isobaric control value indicated by the line with ◎ is approximately the median value of the upper pressure value indicated by the □ line and the lower pressure value indicated by the △ line. It will be taken. In addition, in the case where the curve of the pressure upper limit value and the pressure lower limit value is obtained as in this example, the container can be controlled even if the pressure is controlled by a simple pattern in which a constant pressure indicated by a line marked with ● is applied for a predetermined time. It can be seen that there is no permanent deformation. In short, the isobaric control pattern may be an intermediate value between the pressure upper limit value and the pressure lower limit value, and may be step-type control or control in a polygonal line form. Is possible. In the figure, the circled line indicates the temperature in the retort pot.

A system for supporting control pressure setting for equal pressure control when carrying out the retort sterilization method of the present invention will be described. This support system can be realized using a general-purpose personal computer equipped with input means, storage means, calculation means and a display. Enter the container data such as the volume (ml) and pressure absorption capacity (%) of the container to be used and the filling conditions such as the filling temperature (° C), the HS amount (ml), and the amount of sealed gas (ml) from the keyboard and other input means. To do. For this input, a data input list as shown on the upper side of FIG. 5 is displayed on the display, and a value is input to each corresponding column. The temperature and time settings for temperature rise, sterilization, and cooling are stored as a temperature condition in the kettle so that a plurality of standard patterns can be stored and selected. In addition to this, a free pattern may be set by inputting temperature and time. Further, in consideration of the fact that each value varies, a column for inputting the width may be provided. If necessary information is input to this table, the execution key is clicked and the upper limit pressure value and the lower limit pressure value are calculated by the calculation means based on the equation (a). In addition, the pressure value of constant volume control that does not change the volume of the container is calculated. The calculation result is displayed on the graph display screen as shown in the lower part of Fig. 5. The upper limit pressure value and the lower limit pressure value curve, the retort pot temperature and actual product temperature measured value, and the constant value control pressure value pattern are aligned on the time axis. To display. If the operator plots an appropriate pressure value between the upper limit pressure value and the lower limit pressure value on this display screen, the operator can specify a control pattern that connects the points with a curve or a straight line. When a plurality of points are plotted on the pressure value pattern for constant capacity control, the pressure value pattern for constant capacity control is specified and displayed on the graph display screen. When the pressure control pattern is specified in this way, the execution key is pressed, and the pressure control in the retort pot is automatically controlled according to the specified pressure control pattern. In that case, it is not necessary for the operator to adjust the pressure while observing the inside of the retort kettle, and retort sterilization without causing deformation of the appearance of the container can be performed.
In addition, since the deformation | transformation of the container in a retort sterilization process also occurs by the heat contraction of the container by heating, it is necessary to use a bottle having a heat shrinkage rate of 2% or less, but in this example, 1% was used.
In this specification, the amount of heat shrinkage of the container is 125 ° C. × 30 min in an autoclave test.
Heat shrinkage% = 100 × (Vc−V) ÷ Vc
Is what you want. Here, Vc: container capacity, V: capacity of container after autoclave test In addition to filling conditions such as filling temperature, HS amount, and amount of enclosed gas, calculation factors include heat shrinkage of container, HS temperature during retort, If the dissolved gas amount of the contents, the amount of gas generated during retort sterilization, etc. are adopted, more precise calculation can be performed.

この表の見方はレトルト釜内圧力が0.35ＭPaまで可能な設備であれば、充填温度が２０〜９５℃範囲で、かつＺ値すなわち封入ガス量とＨＳ量の比が0.1〜1.0の範囲まで圧力吸収能が0.5≦Ｙ＜1.5，1.5≦Ｙ＜2.0，2.0≦Ｙ＜3.0，3.0≦Ｙの容器すべてについて対応可能である。レトルト釜内圧力が0.3ＭPaまで可能な設備であっても、充填温度が２０〜９５℃範囲で、かつＺ値が0.1〜1.0の範囲まで圧力吸収能が0.5≦Ｙ＜1.5，1.5≦Ｙ＜2.0，2.0≦Ｙ＜3.0，3.0≦Ｙの容器すべてについて対応可能である。そして、レトルト釜内圧力が0.2ＭPaまでしか可能でない設備であっても、充填温度が２０〜９５℃範囲で、かつＺ値が0.1〜0.4の範囲であれば圧力吸収能が0.5≦Ｙ＜1.5，1.5≦Ｙ＜2.0の容器について本発明によるレトルト殺菌が可能であること、更に圧力吸収能2.0≦Ｙ＜3.0，3.0≦Ｙの容器についてはＺ値が0.1〜1.0の範囲まで対応可能であることを示している。
表６に示したものはレトルト温度を１２５℃とし、ＨＳ量を0.5〜３％の場合である。

この表からは、レトルト釜内圧力が0.35ＭPaまで可能な設備であれば、圧力吸収能が0.5≦Ｙ＜1.5の容器では充填温度が７０〜９５℃範囲で、かつＺ値すなわち封入ガス量とＨＳ量の比が0.1〜1.0の範囲まで対応が可能、圧力吸収能が1.5≦Ｙ＜2.0の容器では充填温度が５０〜９５℃範囲で、かつＺ値すなわち封入ガス量とＨＳ量の比が0.1〜1.0の範囲まで対応が可能、そして圧力吸収能が2.0≦Ｙ＜3.0，3.0≦Ｙの容器については充填温度が２０〜９５℃範囲で、かつＺ値が0.1〜1.0の範囲まで圧力吸収能が対応可能である。レトルト釜内圧力が0.3ＭPaまで可能な設備では、圧力吸収能が0.5≦Ｙ＜1.5の容器については充填温度が７０〜９５℃範囲で、かつＺ値が0.1〜0.8の範囲であれば対応可能であり、圧力吸収能が1.5≦Ｙ＜2.0の容器については充填温度が５０〜９５℃範囲で、Ｚ値が0.1〜1.0の範囲で対応可能であり、圧力吸収能が2.0≦Ｙ＜3.0，3.0≦Ｙの容器については充填温度が２０〜９５℃範囲で、Ｚ値が0.1〜1.0の範囲で対応可能であること。そして、レトルト釜内圧力が0.2ＭPaまでしか可能でない設備であっても、圧力吸収能が0.5≦Ｙ＜1.5の容器では充填温度が７０〜９５℃範囲で、かつＺ値が0.1〜0.3の範囲まで対応が可能、圧力吸収能が1.5≦Ｙ＜2.0の容器では充填温度が６０〜９５℃範囲で、かつＺ値が0.1〜0.4の範囲であれば、本発明によるレトルト殺菌が可能であること、圧力吸収能が2.0≦Ｙ＜3.0の容器については充填温度が４０〜９５℃範囲で、Ｚ値は0.1〜1.0の範囲にわたって本発明によるレトルト殺菌が可能であること、更に圧力吸収能が3.0≦Ｙの容器については充填温度が２０〜９５℃範囲で、かつＺ値が0.1〜1.0の範囲まで対応可能であることを示している。 Below, when performing retort sterilization by the method of the present invention, when the pressure in the retort pot is up to 0.35 MPa, up to 0.3 MPa, or only up to 0.2 MPa, the pressure absorption capacity is 0.5 ≦ The table below shows the calculated filling conditions for containers of Y <1.5, 1.5 ≦ Y <2.0, 2.0 ≦ Y <3.0, 3.0 ≦ Y. In Table 5, the retort temperature is 125 ° C. and the HS amount is 0.5 to 5%.

How to read this table is that the pressure in the retort kettle can be up to 0.35 MPa, the filling temperature is in the range of 20 to 95 ° C, and the Z value, that is, the ratio of the enclosed gas amount to the HS amount is in the range of 0.1 to 1.0. All containers having an absorption capacity of 0.5 ≦ Y <1.5, 1.5 ≦ Y <2.0, 2.0 ≦ Y <3.0, and 3.0 ≦ Y are applicable. Even if the retort pressure is 0.3MPa, the pressure absorption capacity is 0.5 ≦ Y <1.5, 1.5 ≦ Y <until the filling temperature is in the range of 20 to 95 ° C and the Z value is in the range of 0.1 to 1.0. All containers with 2.0, 2.0 ≦ Y <3.0, 3.0 ≦ Y can be handled. Even if the retort pressure is only 0.2 MPa, the pressure absorption capacity is 0.5 ≦ Y <1.5 if the filling temperature is in the range of 20 to 95 ° C. and the Z value is in the range of 0.1 to 0.4. , 1.5 ≦ Y <2.0 can be sterilized by retort according to the present invention, and the pressure absorption capacity of 2.0 ≦ Y <3.0 and 3.0 ≦ Y can correspond to a Z value in the range of 0.1 to 1.0. It is shown that.
In Table 6, the retort temperature is 125 ° C. and the HS amount is 0.5 to 3%.

From this table, it can be seen from the table that if the pressure in the retort kettle is up to 0.35 MPa, the filling temperature is in the range of 70 to 95 ° C. and the Z value, that is, the amount of enclosed gas, in a container having a pressure absorption capacity of 0.5 ≦ Y <1.5. The ratio of the HS amount can be in the range of 0.1 to 1.0, and the container having a pressure absorption capacity of 1.5 ≦ Y <2.0 has a filling temperature in the range of 50 to 95 ° C. and the Z value, that is, the ratio of the enclosed gas amount to the HS amount. It is possible to correspond to the range of 0.1 to 1.0, and for containers with pressure absorption capacity 2.0 ≦ Y <3.0, 3.0 ≦ Y, pressure absorption to the range of 20 to 95 ° C and Z value of 0.1 to 1.0 Can respond. For equipment with a retort pressure of up to 0.3MPa, containers with a pressure absorption capacity of 0.5≤Y <1.5 can be accommodated if the filling temperature is in the range of 70 to 95 ° C and the Z value is in the range of 0.1 to 0.8. For a container with a pressure absorption capacity of 1.5 ≦ Y <2.0, the filling temperature is 50 to 95 ° C. and the Z value is within the range of 0.1 to 1.0, and the pressure absorption capacity is 2.0 ≦ Y <3.0, For containers with 3.0 ≦ Y, the filling temperature is in the range of 20 to 95 ° C. and the Z value is in the range of 0.1 to 1.0. And even in equipment where the pressure in the retort kettle is only possible up to 0.2 MPa, the filling temperature is in the range of 70 to 95 ° C. and the Z value is in the range of 0.1 to 0.3 in a container with a pressure absorption capacity of 0.5 ≦ Y <1.5. Retort sterilization according to the present invention is possible if the filling temperature is in the range of 60 to 95 ° C. and the Z value is in the range of 0.1 to 0.4 in a container with a pressure absorption capacity of 1.5 ≦ Y <2.0. In the case of a container having a pressure absorption capacity of 2.0 ≦ Y <3.0, the filling temperature is in the range of 40 to 95 ° C., the Z value is in the range of 0.1 to 1.0, and the retort sterilization according to the present invention is possible. For containers with ≦ Y, the filling temperature is in the range of 20 to 95 ° C. and the Z value is in the range of 0.1 to 1.0.

レトルト温度１２３℃とし、ＨＳ量を0.5〜３％の場合を表８に示す。

レトルト温度１２０℃とし、ＨＳ量を0.5〜５％の場合を表９に示す。

レトルト温度１２０℃とし、ＨＳ量を0.5〜３％の場合を表１０に示す。

レトルト温度１１８℃とし、ＨＳ量を0.5〜５％の場合を表１１に示す。

レトルト温度１１８℃とし、ＨＳ量を0.5〜３％の場合を表１２に示す。

レトルト温度１１５℃とし、ＨＳ量を0.5〜５％の場合を表１３に示す。

レトルト温度１１５℃とし、ＨＳ量を0.5〜３％の場合を表１４に示す。

以上のデータからの分かるように、本発明では容器の圧力吸収能力を有効に活用し、容器内圧の計算についても関連するデータを計算要素に組み込んだ緻密な計算を実行するようにしたため、レトルト釜内圧力が0.2ＭPaまでのものであっても、１１５℃以上の高温レトルト殺菌を行える。この様に予め式(ａ)を用いて、レトルト設備圧力、容器の圧力吸収能、レトルト殺菌の温度パターンに対して、適正圧力パターンの範囲となるような充填条件（充填温度、ＨＳ量、封入ガス量）を式(ａ)に基づいて算定した表５乃至表１４にようなテーブルを準備しておけば、そのテーブルに基づいて充填条件を容易に選定することができる。 Table 7 shows the case where the retort temperature is 123 ° C. and the HS amount is 0.5 to 5%.

Table 8 shows the case where the retort temperature is 123 ° C. and the HS amount is 0.5 to 3%.

Table 9 shows the case where the retort temperature is 120 ° C. and the HS amount is 0.5 to 5%.

Table 10 shows the case where the retort temperature is 120 ° C. and the HS amount is 0.5 to 3%.

Table 11 shows the case where the retort temperature is 118 ° C. and the HS amount is 0.5 to 5%.

Table 12 shows the case where the retort temperature is 118 ° C. and the HS amount is 0.5 to 3%.

Table 13 shows the case where the retort temperature is 115 ° C. and the HS amount is 0.5 to 5%.

Table 14 shows the case where the retort temperature is 115 ° C. and the HS amount is 0.5 to 3%.

As can be seen from the above data, in the present invention, since the pressure absorption capacity of the container is effectively used, and the calculation of the internal pressure of the container is performed with a precise calculation incorporating related data in the calculation element, the retort kettle Even if the internal pressure is up to 0.2 MPa, high temperature retort sterilization at 115 ° C. or higher can be performed. In this way, using formula (a) in advance, the filling conditions (filling temperature, HS amount, encapsulation, etc.) are within the range of the appropriate pressure pattern for the retort equipment pressure, container pressure absorption capacity, and retort sterilization temperature pattern. If a table as shown in Tables 5 to 14 where the gas amount is calculated based on the formula (a) is prepared, the filling condition can be easily selected based on the table.

In the present invention, since the relationship among the temperature, pressure pattern, container data and filling conditions in the retort kettle can be accurately quantified, the upper limit pressure and lower limit pressure set values in the retort kettle, the filling temperature, the HS amount, and the amount of enclosed gas It is possible to calculate the pressure absorption capacity required as a container for retort sterilization from the filling conditions including
A personal computer having the same input means, storage means, calculation means, and display as in the system for supporting the setting of the control pressure is used as hardware, and the above-described formula (a) is stored in the storage means. When the filling means including the upper limit pressure and the lower limit pressure set value in the retort pot and the filling temperature, the HS amount, and the enclosed gas amount are inputted by the input means, it is necessary based on the formula (a) by the computing means. Calculate the correct pressure absorption capacity. If a function for displaying the result on the display is provided, a pressure absorption capacity design support system for a container to be sterilized by retort can be realized.

It is a graph which shows the relationship between the amount of HS at the time of expansion | swelling of a container provided with the pressure absorption capability, and shrinkage | contraction, and a container internal pressure. It is the graph which displayed the retort pot internal temperature, the product temperature actual measurement value, and the conventional isobaric control pressure pattern in alignment with the time axis | shaft with the curve of the calculated upper limit pressure value and lower limit pressure value. It is a graph which shows the range of the pressure pattern which does not raise | generate a permanent deformation | transformation to the container of retort temperature 125 degreeC. It is a graph which shows the range of the pressure pattern which does not raise | generate a permanent deformation | transformation in the container of retort temperature 115 degreeC. It is a figure which shows the example of the display screen in the pressure control assistance apparatus in the retort pot which concerns on this invention.

Claims (6)

Using a plastic container with a pressure absorption panel with a pressure absorption capacity of 0.5% or more and 5.0% or less applied to at least a part of the body, the internal pressure of the retort kettle at the time of minimum capacity when the panel is in the negative pressure absorption state is controlled. The pressure in the retort kettle is controlled within the range where the pressure at the maximum capacity in the panel positive pressure absorption state is the lower limit pressure, and the internal pressure value at the minimum capacity in the panel negative pressure absorption state And the internal pressure value at the maximum capacity in the panel positive pressure absorption state is the filling condition including the filling temperature, the head space (HS) amount, and the amount of enclosed gas, and the set internal pressure value at the minimum capacity is a negative value. A retort pressure control characterized by using a certain Y and obtaining a set internal pressure value at the maximum capacity by a calculation using a pressure value P (unit: MPa) calculated by the equation (a) using a positive value Y. Way .
P = Pa + Pw−0.1
= 0.098 × (1.03 × T × X × Z) ÷ 293 {D × X + Y + 100 (1-D)}
＋ Pw−0.1 ‥‥‥‥‥‥ (a)
Where Pa is the head space gas pressure, Pw is the saturated water vapor pressure, and the unit is MP.
T: Retort temperature (unit: K)
D: D = Dtl / Dt2 (Dtl: specific gravity of the content liquid at the filling temperature, Dt2: specific gravity of the content liquid at the retort temperature T )
X:% of the head space (HS) immediately after filling in the bottle capacity
Y: Percentage of pressure absorption capacity in bottle capacity (positive pressure absorption Y> 0, negative pressure absorption Y <0)
Z: The ratio of HS to the amount of enclosed gas A Z = A / HS Claims, characterized in that capturing the thermal shrinkage of the container by the ratio Y occupying the bottle capacity of the pressure absorbing ability is a value obtained by subtracting the amount of thermal contraction during the retort sterilization of the formula (a) for the calculation element retort pressure control method according to 1. Based on the formula (a), filling conditions (filling temperature, HS amount, sealed gas amount) that are within the appropriate pressure pattern range for the pressure in the retort pot, the pressure absorption capacity of the container, and the temperature pattern for retort sterilization A filling method comprising preparing a calculated table and selecting filling conditions based on the table.
P = Pa + Pw−0.1
= 0.098 × (1.03 × T × X × Z) ÷ 293 {D × X + Y + 100 (1-D)}
＋ Pw−0.1 ‥‥‥‥‥‥ (a)
Here, Pa: head space gas pressure, Pw: saturated water vapor pressure, and both units are MPa.
T: Retort temperature (unit: K)
D: D = Dtl / Dt2 (Dtl: specific gravity of the content liquid at the filling temperature, Dt2: specific gravity of the content liquid at the retort temperature T )
X:% of the head space (HS) immediately after filling in the bottle capacity
Y: Percentage of pressure absorption capacity in bottle capacity (positive pressure absorption Y> 0, negative pressure absorption Y <0)
Z: The ratio of HS to the amount of enclosed gas A Z = A / HS Provided with input means, storage means, calculation means and display, data related to the container including the pressure absorption capacity, and a data input list for inputting the filling conditions and specifying the temperature pattern in the retort kettle are displayed on the display. If necessary information is entered in this table using the value input means in the corresponding column, the calculation means executes the calculation based on the formula (a) stored in the storage means, and the upper limit pressure value and the lower limit pressure are calculated. A pressure control support system in a retort kettle that has a function to calculate values.
P = Pa + Pw−0.1
= 0.098 × (1.03 × T × X × Z) ÷ 293 {D × X + Y + 100 (1-D)}
＋ Pw−0.1 ‥‥‥‥‥‥ (a)
Here, Pa: head space gas pressure, Pw: saturated water vapor pressure, and both units are MPa.
T: Retort temperature (unit: K)
D: D = Dtl / Dt2 (Dtl: specific gravity of the content liquid at the filling temperature, Dt2: specific gravity of the content liquid at the retort temperature T )
X:% of the head space (HS) immediately after filling in the bottle capacity
Y: Percentage of pressure absorption capacity in bottle capacity (positive pressure absorption Y> 0, negative pressure absorption Y <0)
Z: The ratio of HS to the amount of enclosed gas A Z = A / HS Along with the calculated upper limit pressure value and lower limit pressure value curve, the temperature in the retort pot, the actual product temperature, and the pressure value pattern for constant capacity control are displayed on the display on the graph display screen with the time axis aligned. The retort according to claim 4 , which has a function of specifying a control pattern that connects the points with a curve or a straight line by plotting an appropriate pressure value between the upper limit pressure value and the lower limit pressure value on the screen. Pressure control support system in the pot. An input means, a storage means, a calculation means, and a display, the formula (a) is stored in the storage means, the upper limit pressure and the lower limit pressure set value in the retort kettle input by the input means, a filling temperature, Based on the filling conditions including the amount of HS and the amount of sealed gas, the calculation means has a function of calculating a necessary pressure absorption capacity based on the formula (a) and displaying the result on the display. Retort sterilization container pressure absorption capacity design support system.
P = Pa + Pw−0.1
= 0.098 × (1.03 × T × X × Z) ÷ 293 {D × X + Y + 100 (1-D)}
＋ Pw−0.1 ‥‥‥‥‥‥ (a)
Here, Pa: head space gas pressure, Pw: saturated water vapor pressure, and both units are MPa.
T: Retort temperature (unit: K)
D: D = Dtl / Dt2 (Dtl: specific gravity of the content liquid at the filling temperature, Dt2: specific gravity of the content liquid at the retort temperature T )
X:% of the head space (HS) immediately after filling in the bottle capacity
Y: Percentage of pressure absorption capacity in bottle capacity (positive pressure absorption Y> 0, negative pressure absorption Y <0)
Z: The ratio of HS to the amount of enclosed gas A Z = A / HS

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