JPS60224478A - Direct sterilization of fluid containing solid things and arrangement therefor - Google Patents

Abstract

PURPOSE:A pressure controller is fitted on the end of the high-temperature zone to inhibit temperature fluctuation caused by disturbance in steam feed balance in the instant temperature-raising unit which is induced by flow fluctuation in the pump or pressure controller for feeding the fluid to be sterilized. CONSTITUTION:The fluid to be sterilized is fed from feed pump II and allowed to pass through thin-layer space which is surrounded with a porous material having a plurality of steam-jetting pores on at least one surface and high-temperature steam is introduced from the jacket surrounding the outside of the porous material to effect the instant rise of fluid to be sterilized. In this direct- heating instant sterilization process for fluid, the fluid instantly raised in temperature in part III is kept high in the part IV and the fluid of high temperature is sent through a pressure controller V which varies flow rate depending on pressure change to detect the pressure of the fluid kept at high temperature, when needed, the controller V or pump II are varied in flow rate to control the pressure of the fluid in the high-temperature state.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for heating and sterilizing a fluid by directly blowing steam into a fluid containing solids to instantaneously and uniformly raise the temperature of the fluid to a high temperature.

Conventionally, continuous heat sterilization methods for fluids have been carried out using indirect heating type surface scraping type heat exchangers or direct heating type ultrahigh temperature instant sterilization equipment. However, in the case of this scraped surface heat exchanger, since it is an indirect heating type, it takes a long time to heat all parts of the fluid to be sterilized to the sterilization temperature and then cool it back to the original temperature. For this reason, the processed (
When the sterilization (sterilization) fluid is food, there is a major problem in that it causes deterioration in quality such as color tone, flavor, and nutritional value.

In addition, as shown in Figure 3, the main parts of direct heating type ultra-high temperature instant sterilizers are generally the moment when steam and the fluid to be treated are injected from a nozzle, atomized and mixed, and the temperature of the fluid is instantly and uniformly raised. Temperature rising section ■, high temperature holding section ■, pressure control device installed at the high temperature holding state end that maintains and controls the pressure in the high temperature holding section ■, and cooling the fluid to be treated by evaporating the same amount of water as the injected steam.・It consists of a vacuum cooling water removal section that removes water, and when attempting to process a fluid containing solids, the instantaneous temperature rise section and pressure control device using orifices, valves, etc. may be blocked by solids. However, it was not possible to treat fluids containing solids. Note that I is a supply tank for the fluid to be treated;
■ is the supply pump.

The present invention solves the above problems by using, as a pressure control device, a pump or valve that has the function of continuously or intermittently pumping out solids contained in the fluid to be treated, and at the same time has a clearance between the impeller and the casing. It is resolved.

The present invention relates to a direct heat sterilization method for a fluid containing solids, and the present invention relates to a method for direct heat sterilization of a fluid containing solids. In a direct heating instant sterilization method for a fluid, the fluid is passed through and high-temperature steam is introduced from a jacket surrounding the porous member to instantaneously raise the temperature of the fluid to be sterilized. The fluid to be sterilized is maintained at a high temperature, and the high-temperature fluid to be sterilized is sent out via a pressure control device that changes the flow rate according to changes in the pressure.The pressure of the fluid maintained at high temperature is detected, and the fluid is sent to the pressure control device or as necessary. It is constructed by controlling the pressure of the fluid in the high temperature maintained state by changing the flow rate of the supply pump. As for the method and apparatus for instantaneous heating, for example, there is an instantaneous heating unit disclosed in Japanese Patent Application Laid-Open No. 58-205481.

The apparatus for the above sterilization method includes a thin space surrounded by a porous member having a large number of steam injection holes on at least one side of the porous member for passage of the fluid to be sterilized supplied by the supply pump; An instantaneous temperature raising section is formed from a jacket section that introduces high temperature steam to the outside, a pressure control device is disposed at the end of a high temperature holding section connected to the instantaneous temperature raising section, and at least one of the pressure control device and the supply pump is provided. A flow rate controller is provided in the high temperature holding part, a pressure detector is provided in the high temperature holding part, and the pressure in the high temperature holding part is controlled by operating the flow rate controller to change the flow rate based on a signal from the pressure detector. configured.

Next, the configuration of the present invention will be specifically explained according to FIGS. 1 and 2. In this figure, parts common to those in FIG. 3 already described as a conventional example are given the same reference numerals.

In Figure 1, ■ is the supply tank, ■ is the supply pump, and ■
2 is an instantaneous temperature raising section, 2 is a high temperature holding section, 2 is a pressure control device, and 2 is a decompression/cooling and water removal section, and their functions are the same as those of the conventional device shown in FIG. Also, ■ is a product extraction pump that extracts the product after water removal, ■ is a condenser that condenses water, and ■ is a vacuum pump.

In order to prevent blockage due to solid matter in the fluid, the instantaneous temperature raising section should appropriately set the thin layer space through which the fluid to be sterilized flows to be larger than the size of the solid matter, for example, in the case of a solid matter of 30 mm or less. JP-A-58-20 discloses a method for uniformly and instantaneously heating the fluid by injecting steam at a speed of 10 to 550 m/sec from porous members installed on both sides of the thin layer space.
The instant heating section for high viscosity disclosed in No. 5481 is adopted.

In the present invention, a rotary pump, a rotary valve, or a screw pump as shown in FIG. 2 is used as the pressure control device (2) at the end of the high temperature holding section (1).

In addition, since the fluid to be sterilized is an incompressible fluid, if the flow rate balance between the supply pump and the pump acting as a pressure control device is even slightly disrupted, the instantaneous temperature raising section and high temperature holding section located between the two pumps will be affected. This causes sudden and large pressure changes.

In a direct heating type instant sterilizer, such sudden and large pressure changes in the instant temperature raising section and high temperature holding section will disturb the steam blowing balance in the instant temperature raising section, making it difficult to maintain a constant sterilization temperature. This has a serious impact on sterilization performance in instant sterilization equipment that requires strict control of sterilization temperature and sterilization time. Therefore, in the present invention, pressure control equipment is used. In the pump or pulp, a clearance C is provided between the impeller 1 and the casing 2 to alleviate pressure changes due to the above-mentioned flow rate fluctuations.

The clearance C is determined according to the pressure change in the high temperature holding section (■) when a flow rate fluctuation occurs in either the supply pump (■) or the pump or valve (■) for the pressure control device.
The amount of leakage from the clearance C increases or decreases, which has the effect of absorbing and alleviating the pressure change in the high temperature holding part (2), and the rate of pressure change in the high temperature holding part (2) is adjusted to, for example, 0.1 kg/second.
Therefore, even if the pressure change exceeds the permissible range, for example, about ±0.4 kg/-, the pressure in the high temperature holding part (■) can be detected using only the leakage amount of this clearance. However, by controlling the rotation speed of the pressure control device V or the rotation speed of the supply pump, the pressure in the high temperature holding section can be easily controlled within the allowable range for the set pressure. Therefore, the pressure change can be suppressed to within ±0.4 kg/i with respect to the set pressure only by increasing or decreasing the amount of leakage from the clearance.

Note that the tolerance range referred to here refers to a pressure change that does not cause a change in temperature control of the high temperature holding section.

In this way, in the present invention, by providing the pressure control device at the end of the high temperature holding section, it is possible to prevent the steam blowing balance in the instantaneous temperature rising section from being disturbed due to flow rate fluctuations of the pump or pressure control device that supplies the fluid to be sterilized. This suppresses temperature changes to ensure stable operation. In the present invention, the size of the clearance to be provided to the pressure control device may be appropriately determined mainly depending on the viscosity of the liquid portion of the fluid to be sterilized, and is approximately 0.03 to 0.15 m in most cases.

Further, in carrying out the present invention, the means used as the pressure control device is appropriately determined depending on the size of solids contained in the fluid to be sterilized, the amount of solids to be treated, and the like.

As mentioned above, the present invention can instantaneously raise and cool the temperature for sterilization of fluids containing solids as well as UHT sterilization for liquids, so the influence of the heat mentioned above can be minimized during sterilization processing. You can get good quality ones.

Specific examples of fluids containing solids that can be applied to the present invention include foods such as jam, miso, dressing, grilled meat sauce, soup, meat sauce, juice with grains, sherbet ingredients, curry, stew, and Ogura Anna.

Note that although the present invention has been made for fluids containing solids, it can of course be applied to fluids that do not contain solids.

Test Example A mixture of tomato ketchup and 10 liters of ginseng was used as a model and sterilized in the apparatus shown in FIG.

The instantaneous heating section used in this example had a thin layer space with a thickness of 6 mm, and the pressure control device was a rotary pump with a clearance of 0.1 ts between the impeller and the casing.

The number of viable bacteria in the sterilization conditions, raw materials and products in this example was
Shown in the table.

Table 1 Sterilization temperature Holding time Raw material viable cell count Product viable cell count 'c s
ec (pcs/g) (pcs/g) 120 15.0 4 X 1030 130 6.0 4X1030 140 6.0 4X1030 However, the number of viable bacteria in the product in the table was measured on the liquid part and the solid surface.

Regarding quality, the color tone before and after sterilization was compared by visual inspection, and no difference was observed under all sterilization conditions shown in Table 1.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an apparatus according to an embodiment of the present invention, and FIG. 2 (1) to (
3) is a schematic diagram of various valves used as the pressure control device shown in FIG. 1, and FIG. 3 is a configuration diagram of a conventional device. ■・・・・・・・・・Supply pump■・・・・・・Instant temperature rise section■・・・・・・High temperature holding section■・・・・・・Pressure Control device patent applicant Representative of Kureha Kakoki Co., Ltd. Patent attorney Toru Fujioka Figure 2 (1) (2)

Claims (1)

[Scope of Claims] (11) A fluid to be sterilized supplied by a supply pump is passed through a thin layer space surrounded by a porous member having a large number of steam injection holes on at least one side, and In a direct heating instant sterilization method for a fluid in which high-temperature steam is introduced from a jacket surrounding the fluid to instantaneously raise the temperature of the fluid to be sterilized, the fluid to be sterilized is held at a high temperature and the fluid is exposed to the high-temperature state. The sterilizing fluid is sent through a pressure control device that changes its flow rate in response to pressure changes, the pressure of the fluid being maintained at a high temperature is detected, and the flow rate of the pressure control device or supply pump is changed as necessary to maintain the high temperature. (2) A method for direct heat sterilization of a fluid containing solids, characterized by controlling the pressure of the fluid in a state of A method for direct heat sterilization of a fluid containing solids as set forth in claim (1). (3) A large number of steam injection holes are provided on at least one side for passage of the fluid to be sterilized supplied by a supply pump. An instantaneous temperature raising section is formed from a thin layer space surrounded by a porous member and a jacket section that introduces high temperature steam to the outside of the porous member, and a pressure is applied to the end of a high temperature holding section connected to the instantaneous temperature raising section. A control device is provided, a flow rate controller is provided in at least one of the pressure control device and the supply pump, a pressure detector is provided in the high temperature holding section, and the flow rate controller is activated as necessary based on a signal from the pressure detector. A direct heating sterilization device for a fluid containing solids, characterized in that the pressure in the high temperature holding section is controlled by operating and changing the flow rate. (4) The pressure control device is a rotary pump, and the casing of the rotary pump and impeller approximately 0.03~0
．． Direct heating of a fluid containing solids according to claim (3), characterized in that a clearance of 15 mm is set, and the flow rate can be changed according to changes in the pressure of the high temperature holding part. Sterilizer.