JP2000170698A - Ejector type vacuum generator capable of providing high vacuum - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent reduction in an air sucking ability due to increased temperature of circulating water, in a vacuum generator by a steam ejector and a water ejector or a water-sealed type vacuum pump. SOLUTION: This vacuum generator is provided with a processing tank 2 evacuating the inside thereof, a vacuum pipe line 9 connecting to the processing tank 2, steam ejectors 6 at middle position of the vacuum pipe line 9, and a water ejector 1 or a water-sealed type vacuum pump downstream to the steam ejectors 6 of the vacuum pipe line 9. In this vacuum generator evacuating the inside of the processing tank 2 by sucking air with the steam ejector 6 and the water ejector 1 or the water-sealed vacuum type pump, a heat exchanger 5 absorbing heat in steam transferred into the steam ejector 6 is provided downstream to the steam ejector 6 of the vacuum pipe line 9 and upstream to the water ejector 1 or the water-sealed type vacuum pump.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ejector type vacuum generator capable of obtaining a high vacuum.

[0002]

2. Description of the Related Art As a vacuum generator for use in a vacuum cooling device for cooling foods, there is a vacuum generator using a steam ejector. In the case of a vacuum generator, if the target vacuum degree is relatively low, a vacuum is generated only by a water ejector or a water ring vacuum pump, and if the target vacuum degree is relatively high, the former stage is used. The vacuum is generated by combining the steam ejector provided in the above with a water ejector or a water ring vacuum pump provided in the subsequent stage.

[0003] By providing a steam ejector, it is possible to reach a higher degree of vacuum than when only a water ejector or a water ring vacuum pump is used. However, the steam used in the steam ejector has heat, and the heat of the steam is sent through the vacuum pipe together with the air, and reaches the water ejector or the water ring vacuum pump provided downstream of the steam ejector. The circulating water temperature of the ejector or water ring vacuum pump rises. When the temperature of the circulating water increases, the evaporation of the circulating water increases, so that the amount of air suction by the water ejector or the water ring vacuum pump decreases. Therefore, in order to further increase the degree of vacuum, it is necessary to lower the temperature of the circulating water, and the heat of the circulating water is discharged by a cooling tower or the like.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to reduce the air suction capacity in a vacuum generator using a steam ejector and a water ejector or a water ring vacuum pump due to an increase in the temperature of circulating water. Prevent,
An object of the present invention is to provide a vacuum generator capable of obtaining a high vacuum.

[0005]

[Means for Solving the Problems] A processing tank for evacuating the inside, a vacuum pipe connected to the processing tank and passing air sucked from the processing tank, a steam ejector in the middle of the vacuum pipe, and a steam ejector of the vacuum pipe A water ejector or a water-sealed vacuum pump is also provided downstream, and air is suctioned by a steam ejector and a water ejector or a water-sealed vacuum pump, so that an ejector-type vacuum generator that evacuates the processing tank is used. A heat exchanger that absorbs heat contained in steam sent to the steam ejector is provided downstream of the steam ejector of the vacuum pipe and upstream of the water ejector or the water ring vacuum pump.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an embodiment of the present invention, and is a schematic configuration diagram of a vacuum cooling device provided with a vacuum generating device. The vacuum cooling device evaporates the moisture in the food by evacuating the periphery of the food, thereby removing the heat of the food. The processing tank 2 for storing the food is connected to a vacuum generator by a vacuum pipe 9, and the food is put into the processing tank 2, and the processing tank 2 is evacuated to cool the food. The vacuum generator is provided with two stages of steam ejectors 6 for sucking air in the processing tank by the pressure of steam, and further provided with a water ejector 1 for sucking air in the processing tank by the pressure of water.

[0007] The steam supplied to the steam ejector 6 is generated by the boiler 7, heats water supplied through the water supply pipe 11 to generate steam, and sends the generated steam to the steam ejector 6. The circulating water sent to the water ejector 1 is stored in a circulating water tank 3, a circulating pipe 10 connecting the circulating water tank 3 and the water ejector 1, a circulating pump 8 for sending circulating water to the water ejector 1, and a circulating water. A cooling tower 4 for cooling and a cooling tower pump 12 for sending circulating water to the cooling tower 4 are provided. Further, a heat exchanger 5 is provided downstream of the steam ejector 6 in the middle of the vacuum pipe 9 and upstream of the water ejector 1, and a water supply pipe for supplying water to the boiler 7 to the heat exchanger 5. 11 is connected.

The cooling of the food is carried out by storing the food in the treatment tank 2 and sealing it, supplying the steam to the steam ejector 6 and activating the circulation pump 8 for the ejector. The steam sent to the steam ejector 6 converts velocity energy into pressure energy, sucks air from the processing tank 2, and sends the steam and the sucked air downstream of the vacuum pipe 9. When the ejector circulation pump 8 is operated, the circulation water tank 3
The circulating water inside is sent to the water ejector 1 and the water ejector 1
The air is also sucked by the water.

Downstream of the steam ejector 6, a vacuum pipe 9
Since the steam is fed into the inside of the vacuum pipe and the steam has heat, the heat of the steam is sent in the vacuum pipe 9 and the temperature of the air in the vacuum pipe 9 rises. Vacuum piping 9
A heat exchanger 5 is provided downstream of the steam ejector 6. Heat contained in the air in the vacuum pipe 9 is removed from the vacuum pipe 9 by the heat exchanger 5. The heat exchanger 5 passes through the boiler feed water supplied to the boiler 7,
The heat in the vacuum pipe 9 is transferred to the boiler feed water in the water feed pipe 11 by the heat exchanger 5, so that the air in the vacuum pipe 9 is cooled and the boiler feed water is preheated. The heat in the vacuum pipe 9 which was previously discarded by the cooling tower or the like after passing through the circulating water of the water ejector is recovered and used for preheating the boiler feedwater, so that the fuel consumption of the boiler 7 is reduced. Can be reduced.

Since the air from which heat has been removed by the heat exchanger 5 is sent to the water ejector 1, the temperature rise of the circulating water is suppressed, and the amount of air suctioned by the water ejector 1 is reduced. Is suppressed, and the degree of vacuum is increased. However, even if the heat exchanger 5 is provided,
Since the temperature of the circulating water rises, the circulating water is sent from the circulating water tank 3 to the cooling tower 4, and the cooling tower 4 cools the circulating water. However, since the amount of heat that needs to be discharged from the cooling tower 4 is smaller than in the past, the cooling tower 4 can be smaller in size than the conventionally required cooling tower.

[0011]

According to the present invention, since the temperature rise of the circulating water is suppressed, the capacity of the water ejector or the water ring vacuum pump can be fully utilized, and a high vacuum can be obtained. In addition, heat that was previously discarded is recovered,
Since the temperature of the boiler feedwater can be raised, fuel consumption can be reduced and energy can be saved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a vacuum cooling device provided with a vacuum generator according to one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Water ejector 2 Processing tank 3 Circulating water tank 4 Cooling tower 5 Heat exchanger 6 Steam ejector 7 Boiler 8 Ejector circulation pump 9 Vacuum piping 10 Ejector circulation piping 11 Water supply piping 12 Cooling tower pump

Claims (2)

[Claims] 1. A processing tank for evacuating the inside, a vacuum pipe connected to the processing tank and through which air sucked from the processing tank passes, a steam ejector in the middle of the vacuum pipe, and water downstream from the steam ejector in the vacuum pipe. An ejector or a water-sealed vacuum pump is provided, and air is suctioned by a steam ejector and a water ejector or a water-sealed vacuum pump. A heat exchanger that absorbs heat contained in steam sent to the steam ejector is provided downstream of the steam ejector of the pipe and upstream of the water ejector or the water ring vacuum pump. Ejector-type vacuum generator that can obtain a high vacuum. 2. An ejector-type vacuum generating apparatus according to claim 1, wherein the heat exchanger generates heat of steam sent to the steam ejector and steam sent to the steam ejector. An ejector-type vacuum generator capable of obtaining a high vacuum, wherein heat is exchanged with water supplied to the apparatus.