JPH0787759B2 - Heat sterilizer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a heat sterilizer, and more specifically, it is used for the purpose of setting heat sterilization conditions for liquid food materials and the like prior to the start of actual production. The present invention relates to a small heat sterilizer for testing.

Conventional technology In order to provide consumers with completely sanitized products that do not cause food hygiene problems in response to the diversification of processed foods, the selection of sterilization conditions in the food material processing process is required to set product standards. It is recognized as an important matter.

In order to select the heat sterilization conditions for such processed foods, particularly liquid foods, such as potage and concentrated juice, prior to the start of actual production, small practical machines are often used as test machines.

Problems to be Solved by the Invention When selecting heat sterilization conditions with a small test machine,
It is necessary to create a test condition that can set a sterilization level equivalent to that of an actual production machine from a relatively small amount of sample liquid. More specifically, the amount of sample liquid that can be used in the test stage is generally limited in many cases,
In a conventional tester, if an attempt is made to select a heat sterilization condition applicable to the actual production process from a small amount of sample liquid, an error may occur in the measured value due to the capacity difference between the practical machine and the test machine. Was not a little. For example, when trying to identify the heat sterilization conditions by introducing the sample liquid into a test machine having an internal volume of 5 liters at a rate of 5 liters per hour, it took one hour to fill the test machine and was attached to this test machine. In order to perform heat sterilization treatment for 10 minutes continuously in the hold tank, it is necessary to introduce 0.83 liters of sample liquid in addition to the above 5 liters. That is, even though the volume of the sample liquid to be heat-sterilized is actually 0.83 liters, it is 5
It is impossible to identify the heat sterilization conditions applicable to the actual production process without preparing an extra sample liquid of 1 liter. In order to approximate the test conditions to the heat sterilization conditions in the actual production machine, if the introduction amount of the sample liquid to be supplied to the test machine with the internal volume of 5 liters is set to 100 liters, the test machine will be filled in 3 minutes. However, if a heat sterilization test is continuously conducted for 10 minutes in this state, an additional 16.7 liters of sample liquid is required in addition to the above 5 liters. In many cases, the usable amount of the sample liquid is generally about 1 to 2 liters, and it is almost impossible to consume such a large amount of the sample liquid as a practical problem. In addition, it causes various obstacles to the accuracy maintenance of the heat sterilization condition set by the test machine and the setting of the heat sterilization condition in the actual production machine.

On the other hand, the second problem associated with the conventional tester is the deterioration of the sample solution due to excessive heating. FIG. 10 is a schematic vertical sectional view of a conventional small-sized tester (20) having a single heating source (21) incorporated therein.
For example, a sample liquid flow path (24) is provided by maintaining a minute gap between a lid (23) and a device wall (22) surrounding a heat transfer device connected to a heating steam introducing chamber or a power supply (27). ) Has been formed. The lid plate (23) is provided with an inlet (25) and an outlet (26) for the sample liquid, that is, the liquid to be heated, corresponding to the channel (24). Reference numeral (7) indicates a temperature sensor. By using this type of tester, the sample liquid introduced into the channel (24) can be heated to a temperature from t ₁ to t ₂ and a desired sterilization test can be performed. In this heat sterilization method, as shown in FIG. 11, it is possible to use a heat medium having a substantially constant temperature such as steam or a heat transfer device, and various sample liquids including liquid foods due to the simple heating mechanism. Has been evaluated for its practicality as a test heat sterilizer. However, in this heat sterilization method, there is a large difference between the inlet temperature t ₁ of the sample solution and the heat medium temperature T, and there is a possibility that the sample solution, which is sensitive to heat, may be damaged or deteriorate. On the other hand, FIG. 12 shows that a low temperature sample liquid having a temperature of t ₁ flows from the inlet (25) side to the flow path (2
4) The heat sterilization method is shown in which the temperature of the heat medium changes almost linearly from T ₁ to T ₂ while flowing into the 4) and flowing out from the outlet (26) while being heated to a high temperature of t _2. . In this method, the temperature gradient of the heating medium, that is, the heating wall surface, is made opposite to the flow direction of the sample liquid, so that the sample liquid inlet (25)
Further, the temperature difference (T ₂ −t ₁ ) between the heat medium and the sample solution at the outlet (26) is reduced to prevent the sample solution from being deteriorated due to abrupt heating. This heat sterilization device is frequently used for setting heat sterilization conditions for various products including liquid foods, as it provides a heat exchange system suitable for preventing deterioration of the quality of the sample liquid. However, this method also has a capacity limitation, and its improvement has been demanded. The present invention was made with the intent of further improving the known heat sterilization apparatus as described above, and its main purpose is to efficiently apply heat sterilization conditions applicable to an actual production machine from a small amount of sample liquid. It is to provide a small heat sterilizer for testing that can be selected for.

MEANS FOR SOLVING THE PROBLEMS As a means for achieving the above object, the present invention is directed to a lid which is arranged to face a container containing a heat source and a surface of the container with a minute gap therebetween. In the heat sterilizer having a plate and a sample solution outlet / inlet connected to the lid plate at a predetermined interval, a small gap between the surface of the vessel wall of the body and the inner surface of the lid plate is filled with the sample solution. The present invention provides a heat sterilizer which is configured as a flow path and in which the surface of the vessel wall in contact with the sample solution is formed in a plurality of heating temperature regions having different surface temperatures along the flow direction of the sample solution.

Effect According to the device of the present invention, the temperature of the sample solution and the surface temperature of the vessel wall are close to each other over the entire flow path of the sample solution, and the heat sterilization conditions applicable to the actual production machine are accurately set.

Example 1 FIG. 1 is a schematic vertical cross-sectional view illustrating the structure of a heat sterilizer according to the present invention, and FIG. 2 is a plan view of a heat source built-in device taken along the line AA in FIG. . The heat source built-in body (hereinafter, abbreviated as body and denoted by reference numbers 1 and 10) is a heating device in which electric heaters (2a) and (2b) and a heating medium such as oil or hot water are enclosed. The lid plate (4) is arranged so as to face the vessel wall surface of the body (1) with a slight gap. The lid plate (4) is fixed to the body (1) via a tightening bolt (not shown) and a gasket (11). A sample liquid inlet (6) and an outlet (5) are opened in the lid (4) at predetermined intervals, and the inner surface (4a) of the lid plate (4) and the vessel wall (13) are separated from each other. A flow path (12) for the sample liquid is formed with a fine gap maintained between the outer surfaces. The size of this minute gap depends on the characteristics of the sample solution to be heat-sterilized and the capacity of the tester, for example, 1 m.
Set to about m to 3 mm. Reference numbers (2a) and (2b)
Is an electric heater that functions as a heating source for the sample liquid, and two electric heaters (2
a) and (2b) are placed adjacent to each other. Electric heater (2a) (2
b) is connected to a power source (8) via a temperature control circuit (not shown), and correspondingly, the vessel body (13) on the side of the sample liquid flow path (12) has a vessel body (1). Temperature sensors (7a) and (7b) for detecting the surface temperature of the are arranged at predetermined intervals.

The set temperatures of the electric heaters (2a) and (2b) are different, and the surface temperature of the vessel wall (13) located on the sample liquid inlet (6) side for introducing the low temperature sample liquid as shown in FIG. T ₁ is the outlet of the sample solution taken out of the hot after being heat sterilized (5) temperature to be lower than the surface temperature T ₂ of the device body wall positioned on the side (13) is set. That is, the low temperature sample liquid having the temperature t ₁ introduced into the flow channel (12) from the introduction port (6) comes into contact with the surface of the vessel wall (13) having the surface temperature T ₁ and is heated, 12) Wall that moves in and has surface temperature T ₂ (13)
It reaches the surface of, and is heated here to a temperature t ₂ and discharged from the outlet (5) in a sterilized state. The temperature sensor (7a) and (7b) is a temperature detecting means for maintaining the surface temperature T ₁ and T ₂ of the container wall (13), the temperature t ₁ and the sample liquid
The current flowing through the electric heaters (2a) and (2b) corresponding to t ₂
ON / OFF control is performed to maintain the surface temperature of the body (1) partitioned by the heat insulating partition (3) at T ₁ and T ₂ . As illustrated in FIG. 2, the heat insulating partition wall (3) is arranged at right angles to the flow direction of the sample liquid, and the sample liquid is placed along the flow direction by 2
When divided, the surface temperature of the body (1) that comes into contact with the sample solution is divided into _two at right angles to the flow into T ₁ and T ₂ (where T ₂ > T ₁ ).
As shown in the figure, a stepwise temperature gradient along the flow direction of the sample liquid is obtained. As a result, the flow path (12) from the inlet (6)
The sample liquid that has flowed into the temperature rises in a curve from the initial temperature t ₁ to the final sterilization temperature t ₂ and is discharged from the system through the outlet (5). By diverting the liquid feed amount and the heat sterilization temperature set in this way, it is possible to efficiently select the heat sterilization conditions applicable to the actual production machine from a small amount of the sample liquid.

Example 2 FIG. 4 is a schematic vertical sectional view showing another specific example of the heat sterilizer, and FIG. 5 is a temperature distribution diagram thereof. In the following description, device components common to those of the first embodiment are denoted by the same reference numerals as in FIG.

In this heat sterilizer, the surface of the vessel wall (13) is T ₁ ,
It is divided into 5 heat sterilization zones having a stepwise temperature distribution of T ₂ , T ₃ , T ₄ and T ₅ , and in this state the sample solution of initial temperature t ₁ is introduced from the inlet (6) to the flow channel (12). It is introduced into the outlet (5) while being brought into contact with the above-mentioned heat sterilization area and subjected to a predetermined sterilization treatment. According to this heating method, as shown in FIG. 5, the sample solution is heated stepwise from the initial temperature t ₁ to the final temperature t ₂ and in a curved manner while flowing out through the flow outlet (5). ).

Similarly, FIG. 6 shows a case where the surface of the vessel wall (13) is divided into 10 heat sterilization zones having surface temperatures T _{1 to} T _10, and the inside of the flow path (12) is introduced from the inlet (6). The sample liquid that has flowed into the chamber is heated stepwise from the initial temperature t ₁ to the final temperature t ₂ .

As can be understood from the above description, the greater the number of divisions of the instrument wall (13) that constitutes the sample liquid flow path (12), the smaller the difference between the surface temperature of the instrument wall (13) and the temperature of the sample liquid, A heat sterilization state close to that of a real production machine can be obtained.

Example 3 FIG. 7A shows that the surface of the vessel wall (13) is perpendicular to the flow of the sample solution.
FIG. 7B shows the case of dividing into two heat sterilization zones having surface temperatures T ₁ and T ₂ , and FIG. 7B shows the surface of the vessel wall (13) at right angles to the flow of the sample solution at T ₁ , T ₂ and T _{2. The} figure shows the case of being divided into three heat sterilization zones having a surface temperature of 3. However, the temperature division direction of the surface of the vessel wall (13) does not necessarily need to be orthogonal to the flow direction of the sample solution, and the arrangement of the heat insulating partition (3) is devised as shown in FIG. 8A. Therefore, it is possible to incline with respect to the flow direction of the sample liquid.
As a modification, as shown in FIG. 8B, the sample liquid flow path (12) is curved in a U-shape, and the temperature division pattern of the surface of the vessel wall (13) is adjusted according to this flow path shape. May be.

Embodiment 4 FIG. 9 is a schematic longitudinal sectional view of a heat sterilizer using hot water or liquid heat medium having different temperatures as a heat source instead of an electric heater. Reference numbers 9a, 9b, 9c, 9d, and 9e are hot water or liquid heat medium flow passages provided in the body (1), and the temperature of these flow passages partitioned by the heat insulating partition (3) is shown. It is possible to form a plurality of heat sterilization zones having different surface temperatures of the body (1) between the lid plate (not shown) and the vessel wall (13) by passing different hot water or liquid heat medium of different types. it can.

Effect of the Invention By using the heat sterilization apparatus according to the present invention, it is possible to carry out a heat sterilization test under various temperature conditions from an extremely small amount of sample liquid. In this way, the heat sterilization test suitable for saving the sample liquid consumption and the test time is accurately performed under the conditions close to the settings and temperature conditions of the actual production machine.

[Brief description of drawings]

1 is a schematic longitudinal section of a heat sterilizer according to the present invention, FIG. 2 is a plan view of a heat source built-in device taken along line AA of FIG. 1, and FIG. 3 is an apparatus of FIG. It is a temperature-heat sterilization path | route long-line figure in FIG. FIG. 4 is a schematic vertical sectional view showing another specific example of the heat sterilization apparatus, and FIG. 5 is a temperature-heat sterilization path long line diagram of this apparatus. Figure 6 shows the surface temperature of the vessel wall at 10
It is a temperature-heat sterilization path | route long line figure of the heat sterilizer which changed it to the step. 7A and 7B and FIGS. 8A and 8B are explanatory views of the temperature division system of the heat source built-in device, and FIG. 9 is a vertical cross-sectional view of the device of the present invention using a liquid heating medium. Also,
FIG. 10 is a schematic vertical cross-sectional view of a conventional small heat sterilization device for testing, and FIGS. 11 and 12 are temperature-heat sterilization path long lines in the conventional device shown in FIG. 1 ... Vessel, 2a, 2b ... Electric heater, 3 ... Adiabatic partition wall, 13 ... Surface of vessel wall, t ... Sample liquid temperature, T ... Heat medium temperature,

Claims (1)

[Claims] 1. A container containing a heat source, a lid plate facing the surface of the container with a minute gap therebetween, and a sample connected to the lid plate at a predetermined interval. In a heat sterilizer having a liquid inflow / outflow port, a minute gap between the surface of the vessel wall of the vessel and the inner surface of the lid plate is configured as a flow path for the sample fluid, and the surface of the vessel wall flows through the sample fluid. A heating and sterilizing device formed in a plurality of heating temperature regions having different surface temperatures along the direction.