JPH01124349A - Sterilizer for fruit, vegetable of the like - Google Patents

Abstract

PURPOSE:To destroy eggs of insect pests and larvae infiltrating into the interior without damaging freshness, flavor and appearance, by wholly heating fruits and vegetables by using latent heat of condensation of low-temperature steam under reduced pressure in a short time. CONSTITUTION:Fruits and vegetables are stored in preserving boxes 7, the plural boxes are piled and plural pairs of the boxes are placed on a pallet 24. The pallet is stored in a vacuum container 1 by a roller conveyor 11, outer pressure is cut off and the container is made into a vacuum state by operating a vacuum pump 6. Then steam from a boiler is fed to a saturated steam generating device 16, made into low-temperature saturated steam, passed through and raised in the preserving boxes 7, the fruits and vegetables in the boxes 7 are rapidly heated by latent heat of the low-temperature saturated steam. Then water is circulated and sprayed, the fruits and vegetables are cooled. Consequently, larvae can be destroyed without damaging freshness, flavor and appearance.

Description

[Detailed Description of the Invention] A method of killing insects by steam heating and immediately cooling the insects to below room temperature by vacuum without impairing the freshness, flavor, appearance, etc. of the fruits, vegetables, etc. It is.

Conventionally known methods involve immersing insects in hot water to kill insects at elevated temperatures; however, this is a heat exchange method that relies on the sensible heat of the hot water, so it takes time, and it is difficult to raise the temperature uniformly over the entire body. Another method is to spray hot water into an atmospheric chamber and mix it with the air flow to obtain a predetermined temperature and use it for insecticidal purposes, but it is extremely difficult to maintain and adjust the temperature. There was something.

In order to eliminate this conventionally known defect, the uninvented invention aims to uniformly raise the temperature of fruits, vegetables, etc. throughout a short period of time by effectively utilizing the heat of low-temperature steam under reduced pressure. is completed and after a predetermined period of time has passed at a predetermined temperature,
The steam supplied from the outside to the saturated steam generator is stopped, the circulation pump is driven, the wood inside the container is sprayed from the spray nozzle installed at the top of the container, the wood is cooled by self-evaporation, and the primary steam booster is driven. The present invention provides a method in which the vacuum inside the container is increased, and the inside of the container is further vacuum-cooled using water that has been cooled to a saturation temperature by self-evaporation.

Next, the present invention will be explained with reference to the implementation diagram shown in FIG. The fruits and vegetables to be processed are stored in a storage box (7) made of polypropylene or other plastic with many ventilation holes at the bottom.
Multiple stacks of these are placed on a pallet (24) made to have ventilation in the rigid direction.
Guided by a roller conveyor (11), the vacuum container (1
), and the doors (la) and (1d) on both sides
The vacuum container (1) is maintained in a vacuum state using the vacuum pump (6), and the steam pipe (12) is passed from the external boiler (see figure 10) to the nozzle (13). The heating steam is supplied to the evaporation water in the saturated steam generator (16) to generate low-temperature saturated steam in the container, and the roller conveyor (11), pallet (24),
It passed through the inside of the storage box (7) and was raised due to the differential pressure, and was then stored in the storage box. The temperature of fruits or vegetables is rapidly raised by the latent heat of low-temperature saturated steam.

A vacuum container (
1) and the saturated steam generator (16), a partition plate (2) is provided. The temperature in the vacuum container (1) is set to a temperature that kills eggs or larvae of pests on fruits or vegetables and does not impair the original freshness, flavor, and appearance of the fruits or vegetables. Saturation temperature is temperature adjusted &-+
(17), detected by the vacuum control valve (18),
Adjustment is maintained at a constant level.

The water temperature in the saturated steam generator (16) is controlled by a temperature controller (1
4), and by the steam flow rate control valve (15),
It is regulated and maintained at a constant temperature. Excess steam is cooled and condensed by the cooling water at the cooling water inlet (22) and cooling water outlet (23) of the surface condenser (5), and then transferred to the recovery tank (19).
The non-condensable gas is discharged out of the system by a vacuum pump (6).

Noboru! Il! After the insecticidal treatment is completed, the steam supply from the external boiler is stopped, and the saturated steam temperature in the vacuum container (1) is lowered depending on the vacuum level of the capacity cup of the vacuum pump (6).
Next, the steam booster (4) provided between the vacuum container (1) and the surface condenser (5) is driven to increase the vacuum inside the vacuum container and further lower the saturated steam temperature by self-evaporation. Stored in stacked storage boxes (7),
Fruits or vegetables are cooled by latent heat due to self-evaporation of water that resists landing, but since the amount of heat is insufficient to cool the internal heat of fruits or vegetables, a pump ( According to 8), a plurality of spray nozzles (1) installed in the upper part of the vacuum container spray and circulate cold water cooled by self-evaporation onto the fruits or vegetables stored in the storage box (7), thereby cooling the fruit or vegetables. In order to improve the effectiveness, we were able to shorten the process to 3 hours, as shown in the implementation man-hour diagram in Figure 2.

As per this implementation time chart, we used domestic apple materials and subjected them to heating and cooling treatments, and compared the freshness, flavor, appearance, cut surface, etc. of treated fruits and untreated fruits. However, no discrimination was found, and the results after storage at room temperature for 12 days also showed no discrimination. Therefore, conventionally known devices are large and
Compared to conventionally known products, the product of the present invention not only improves the quality after processing such as freshness, flavor, and appearance, but also allows heating and cooling to be operated with the same equipment. This has the effect of reducing equipment costs, personnel costs, and expenses, and improving efficiency.

[Brief explanation of the drawing]

FIG. 1 is a process explanatory diagram showing an embodiment of the insecticidal device for fruits, vegetables, etc. of the present invention. FIG. 2 is a diagram of the number of man-hours required for the present invention. 1-111 vacuum container 1a, 1a---one door
2---Partition plate 3---Series pipe
4-1--Steam booster 5--Surface condenser 6--Vacuum pump 7--
--Storage box 8---Pump 9-11 Circulation pipe 1O---The W Sui nozzle 11
--- One roller conveyor 12 --- Steam pipe
13---Nozzle 14---1 Temperature controller +5---Steam flow rate control valve 1B---1 Saturated steam generator 17---Temperature controller +8---
-Vacuum control valve 19--Collection tank
20---1 Steam valve 21---Flow control valve 2
2---1 Cooling water inlet 23-1---Cooling water outlet 24---Pallet

Claims (1)

[Claims] A saturated steam generator is attached to a horizontal cylindrical or rectangular vacuum container, and multiple storage boxes with numerous ventilation holes at the bottom for storing fruits, vegetables, etc. are stacked together, and multiple sets of stacked storage boxes are stacked in a rigid direction. The tower is placed on a pallet with a ventilated structure, guided by a roller conveyor installed at the bottom of the vacuum container, placed inside the vacuum container, and a partition plate is attached to the flat outer periphery of the roller conveyor to isolate the steam generator from the vacuum container. The steam generated by the saturated steam generator passes through and rises inside the storage box due to the differential pressure, and doors that can be opened and closed are provided on both sides of the vacuum container so that the inside of the vacuum container can always be isolated from external pressure.
The generated saturated steam passes through the storage box and raises the temperature of fruits, vegetables, etc., and is connected to a vacuum pump with a surface condenser to maintain a constant vacuum in the vacuum container and adjust the saturated heating steam temperature. After the temperature raising operation was completed, the supply of heated steam to the saturated steam generator was stopped, and water was circulated and sprayed by a pump from the spray nozzle installed in the vacuum container to vacuum cool the inside of the vacuum container. Features: Insect killing device for fruits, vegetables, etc.