JPH11148757A - Vacuum cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To permit steam sterilization of inside of not only a cooling tank but also pipelines, such as a vacuum inducing line and the like, and prevent growth of miscellaneous bacteria or generation of bad smell, by a method wherein a steam supplying means, supplying steam into the cooling tank of a vacuum cooling device during stopping the cooling operation of the vacuum cooling device, is provided. SOLUTION: Upon cooling operation of a vacuum cooling device provided with a cooling tank 1, an evacuating line 2 and an outdoor air introducing line 3, cooling liquid is supplied from a cooling liquid line 15 into a heat exchanger 5 and air in the cooling tank is evacuated through the evacuating line 2 by the starting of a vacuum pump 6. When sterilizing operation is effected during stopping the cooling operating of the vacuum cooling device, an opening and closing door is close and, thereafter, an outdoor air introducing valve 9 is closed and a steam supplying valve 19 is opened to supply steam from a steam line 18 into the cooling tank 1 and sterilize the inside of the cooling tank 1 by the steam. The steam, supplied into the cooling tank 1, is discharged thereafter through the evacuating line 2, a steam ejector 4, a heat exchanger 5 and the vacuum pump 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum cooling device for evaporating the water content of an object to be cooled under reduced pressure and using the latent heat of vaporization for cooling.

[0002]

2. Description of the Related Art A vacuum cooling device is designed to reduce a saturated steam temperature by evacuation and decompression of a cooling tank containing an object to be cooled, and to evaporate water in the object to be cooled. The object to be cooled is cooled using latent heat of vaporization. This vacuum cooling device is used, for example, in the food industry in a process of packing and shipping cooked food.

[0003] In such a vacuum cooling device, during vacuum suction, food fragments and fine particles may scatter around the cooling tank or may be sucked into the vacuum suction line. The fragments cause the propagation of various bacteria and the generation of offensive odors. In order to solve this problem, it is necessary to frequently clean various pipes such as the inside of the cooling tank and the vacuum suction line, but the cleaning work requires much labor. For this reason, this cleaning work is usually only about flushing with water or hot water, and this cannot completely prevent propagation of the above-mentioned various bacteria and generation of offensive odor.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to reliably prevent the propagation of various germs and the generation of offensive odor in a cooling tank or a pipe in a vacuum cooling device.

[0005]

Means for Solving the Problems The present invention has been made to solve the above-mentioned problems, and the invention according to the first aspect of the present invention relates to a method of manufacturing a vacuum cooling device while the cooling operation of the vacuum cooling device is stopped. And a steam supply means for supplying steam into the cooling tank.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is realized by providing steam supply means in a cooling tank of a vacuum cooling device. Then, the steam supply means supplies steam into the cooling tank while the cooling operation of the vacuum cooling device is stopped. In such a vacuum cooling device, the cooling tank is usually configured to be hermetically sealable, and sterilization in the cooling tank can be performed by supplying steam to the closed cooling tank. In addition, the sterilization can prevent the generation of offensive odor due to the propagation of various bacteria. As described above, since the sterilization in the cooling tank can be performed while the operation of the vacuum cooling device is stopped, by storing cooking utensils, tableware, and other things in the cooling tank during the operation stop. Also, sterilization of these cooking utensils and the like can be performed. Therefore, a workplace environment where a vacuum cooling device is installed in the food industry or the like can be hygienically maintained. In addition, since the above sterilization is performed while the operation of the vacuum cooling device is stopped, it is possible to effectively use idle time that does not hinder business.

Here, the steam supply means includes steam generation means such as a boiler, a steam line for supplying steam from the steam generation means to the cooling tank, and control means for controlling the supply of steam. It is. Although the steam line can be provided as a dedicated device for supplying steam to the cooling tank, the vacuum cooling device itself includes a steam using device, or a steam using device is provided around the vacuum cooling device. If installed, a steam line that is also used as these steam-using devices may be used. Here, as the steam-using device provided in the vacuum cooling device itself,
A steam ejector mounted on a vacuum suction line to facilitate vacuum suction is typical. Examples of the steam-using equipment installed around the vacuum cooling device include a steamer and a steamer. If such a steam-using device is installed on or around the vacuum cooling device itself, steam generation means and a steam supply line are already installed for these steam-using devices. can do.

[0008] The steam supplied into the cooling tank is discharged using a vacuum suction line of the vacuum cooling device.
The drain in which the vapor is condensed is discharged from the vacuum suction line and a drain outlet provided in the cooling tank.
In particular, when discharging from the vacuum suction line, not only the cooling bath but also the inside of the vacuum suction line can be sterilized. That is, since pieces or fine particles of the object to be cooled (for example, foods) may be sucked from the cooling tank into the vacuum suction line, sterilization including these pieces can be performed.

Here, some vacuum cooling devices include a heat exchanger in the vacuum suction line in order to improve the cooling performance. The heat exchanger promotes vacuum suction from the cooling tank by condensing negative-pressure steam in the vacuum suction line, thereby increasing the efficiency of vacuum cooling. In the vacuum cooling device having such a configuration, the vacuum suction line including the heat exchanger can be sterilized.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a drawing for explaining a schematic configuration of a first embodiment of a vacuum cooling device according to the present invention.

Referring to FIG. 1, the basic structure of a vacuum cooling device will be described first. This vacuum cooling device includes a cooling tank 1 for hermetically containing an object to be cooled, and a vacuum suction line 2 for reducing the pressure of the cooling tank 1. And an outside air introduction line 3 for returning the pressure in the cooling tank 1 to atmospheric pressure after vacuum cooling. The cooling tank 1 is provided with an opening / closing door (not shown) for operations such as taking in and out of an object to be cooled, and this opening / closing door has a sealable configuration. The vacuum suction line 2 is provided with a steam ejector 4, a heat exchanger 5, and a liquid ring vacuum pump 6 in this order from the cooling tank 1 side. A check valve 7 for maintaining a reduced pressure state is provided between the cooling tank 1 and the steam ejector 4. A filter 8 is provided at the upstream end of the outside air introduction line 3, and an outside air introduction valve 9 is provided between the filter 8 and the cooling tank 1.

The steam ejector 4 has a suction-side end 1.
0 is connected to the cooling tank 1, its exhaust side end 11 is connected to the heat exchanger 5, and the steam inlet 12 is connected to a steam supply line 13 extending from steam generating means (not shown). . The steam supply line 13 is provided with a steam control valve 14 for interrupting the supply of steam to the steam ejector 4.

The heat exchanger 5 cools the fluid from the steam ejector 4 and condenses the vapor in the fluid. The coolant for condensing the vapor is sent from the coolant line 15 to the heat exchanger 5.

The liquid ring vacuum pump 6 removes the fluid that has passed through the heat exchanger 5 by suction and removes the air in the cooling tank 1 by negative pressure suction, and condenses the heat in the heat exchanger 5. The discharge of unsuccessful steam is performed. The liquid ring vacuum pump 6 is connected to a water sealing line 16 for supplying water. The water sealing line 16 is branched from the cooling liquid line 15.

The filter 8 removes dust and various germs in the outside air introduced into the cooling tank 1 to prevent the filter 8 from adhering to the object to be cooled. The outside air introduction valve 9 is
Although it is possible to control the introduction and stop of the outside air by using an on-off valve, as in the first embodiment, an electric valve that can change the air introduction amount (ventilation resistance) continuously or in several steps. It is preferable to adjust the flow rate of the decompression pressure by adjusting the flow rate of the air flowing into the cooling tank 1 from the outside air introduction line 3 by using the above.

Further, in this vacuum cooling device, a steam supply means 17 is provided in the cooling tank 1. The steam supply means 17 includes a second steam line 18 and a steam supply valve 19. The second steam line 18 is connected to the steam supply line 1
3, a branch is made between the steam control valve 14 and the steam ejector 4 and connected to the upper part of the cooling tank 1.
The steam supply valve 19 is provided in the second steam line 18.

Further, a control device 20 is provided in the vacuum cooling device. The control device 20 includes the water-sealed vacuum pump 6, the outside air introduction valve 9, and the steam control valve 1.
4 and the steam supply valve 19 are controlled. In addition, the control device 20 controls the supply of the coolant to the heat exchanger 5 by the coolant line 15. Further, the control device 20 includes an operation switch 21
The operation switch 21 instructs the control device 20 to operate the vacuum cooling device, including the cooling operation, the sterilization operation, and the operation stop. The following description explains the operation of the vacuum cooling device according to the present invention, including the function of the control device 20.

In the above configuration, the cooling operation will be described. First, an object to be cooled is stored in the cooling tank 1, and a work opening / closing door (not shown) is closed. At this time, the outside air introduction valve 9, the steam control valve 14, and the steam supply valve 19 are closed. Next, the operation switching device 21 controls the control device 20.
To the cooling operation. Then, water is supplied from the water sealing line 16 to the liquid ring vacuum pump 6, and the liquid ring vacuum pump 6 is started. Further, the coolant is supplied to the heat exchanger 5 from a coolant line 15. When the liquid ring vacuum pump 6 is started, the air in the cooling bath 1 is vacuum-suctioned through the vacuum suction line 2. And the cooling tank 1
Since the saturated steam temperature decreases as the internal pressure decreases, the water content of the object to be cooled in the cooling tank 1 evaporates actively,
This steam is supplied to the vacuum suction line 2 together with the air described above.
Is sucked by The object to be cooled is cooled by the latent heat of vaporization accompanying the evaporation of the water in the object to be cooled.

The mixed fluid of air and steam from the cooling tank 1 is cooled in the heat exchanger 5 and the steam is condensed.
Therefore, most of the gas that needs to be evacuated by the liquid ring vacuum pump 6 is air, and the vacuum suction by the liquid ring vacuum pump 6 is performed in a short time. When the pressure in the cooling tank 1 becomes extremely low, it is difficult for the liquid ring vacuum pump 6 alone to reduce the pressure.
Therefore, a detecting means such as a temperature detector (not shown) or a pressure detector (not shown) is attached to the cooling tub 1, and the state of the cooling tub 1 is monitored by the detecting means, and a predetermined pressure or When the temperature reaches a predetermined temperature, the steam control valve 14 is opened and the steam ejector 4 is operated.

When the steam control valve 14 is opened, steam from the steam supply line 13 flows into the steam introduction section 12 of the steam ejector 4, and the fluid force of the steam causes the air in the cooling tank 1 and the air from the object to be cooled. The steam is sucked from the suction side end 10, and discharged together with the steam from the steam supply line 13 while being pressurized from the exhaust side end 11.

The exhaust-side end 11 of the steam ejector 4
The mixed fluid of air and steam discharged from the chiller is cooled in the heat exchanger 5 in the same manner as described above, and the steam of the mixed fluid is rapidly condensed. Is air. On the downstream side of the steam ejector 4, the pressure of the mixed fluid is increased by the steam ejector 4 and the saturated steam temperature of the mixed fluid is increased even though the pressure in the cooling tank 1 is extremely low. The capacity of the exchanger 5 increases. Further, the partial pressure of air at the outlet side of the heat exchanger 5 is increased, and the vacuum suction by the liquid ring vacuum pump 6 is efficiently performed in a short time. As described above, the ultimate pressure in the cooling bath 1 decreases, and the cooling temperature accordingly decreases.

As described above, when the pressure in the cooling tank 1 is reduced and the object to be cooled is cooled to a predetermined temperature, the steam control valve 14 is closed to stop the supply of steam to the steam ejector 4. Then, the liquid ring vacuum pump 6 is stopped. Then, the outside air introduction valve 9 is opened, and air is introduced into the cooling tank 1 from the outside air introduction line 3 to return to the atmospheric pressure. Thereafter, the door is opened, the object to be cooled is taken out of the cooling tank 1, and the cooling operation of the vacuum cooling device is stopped. The above-described series of cooling operations is automatically performed after the operation switching unit 21 instructs the control device 20 to perform the cooling operation. Here, when the cooling operation is stopped halfway, the operation switch 21
To instruct the control device 20 to stop.

After the object to be cooled is taken out of the cooling tank 1, the sterilizing operation is performed while the cooling operation of the vacuum cooling device is stopped.
Instructs the control device 20 to that effect. The control device 20 closes the outside air introduction valve 9 and controls the steam supply valve 19
Is opened to supply steam from the second steam line 18 into the cooling tank 1, and the steam is used to sterilize the cooling tank 1. The steam flowing into the cooling tank 1 further reaches a liquid ring vacuum pump 6 from a vacuum suction line 2 via a steam ejector 4 and a heat exchanger 5 on the way, and the liquid ring vacuum pump 6 Emitted after passing. Therefore, in this vacuum cooling device, not only the cooling tank 1 but also the vacuum suction line 2 and the steam ejector 4 provided in the middle thereof.
And the inside of each device such as the heat exchanger 5 can be sterilized. And after continuing the sterilization operation for a predetermined time,
The operation switch 21 instructs the control device 20 to stop the sterilization operation. Then, the control device 20
The outside air introduction valve 9 is opened and the steam supply valve 19 is closed to stop the sterilization operation. The sterilization operation may be configured to be automatically terminated after a predetermined time has elapsed by incorporating timer means or the like into the control device 20. In the case of such a configuration, a desired sterilization operation time according to the use state of the vacuum cooling device and the operation time may be appropriately set in the control device 20.

As described above, the vacuum cooling device according to the present invention provides the steam supply means 17 while the cooling operation of the vacuum cooling device is stopped.
Is operated to sterilize the cooling tank 1, the vacuum suction line 2, and each device (steam ejector 4, heat exchanger 5, etc.) provided in the vacuum suction line 2. Here, utilizing the fact that the operation of the steam supply means 17 is during the stop of the cooling operation of the vacuum cooling device, the cooking utensil and the like are stored in the cooling tank 1 after the work or during the stop of the cooling operation at night or the like. By doing so, steam sterilization of the cooking utensil or the like can be performed. Further, by storing cooking utensils and the like in the cooling tub 1 during the cooling operation being stopped, the cooling tub 1 can be used as a storage for cooking utensils and the like, so that effective use of space can be achieved. That is, the vacuum cooling device of the present invention can be used also as a sterilizing device and a storage, and one device can obtain functions of three devices, which is extremely effective in practical use.

Here, in the first embodiment, the second steam line 18 is configured to be branched from the steam supply line 13, but the second steam line 18 does not include a steam-using device such as the steam ejector 4 described above. In the above, the steam supply line 13 can be used as the steam supply means 17 by directly connecting the steam supply line 13 to the cooling tank 1 and providing a steam supply valve 19 in the steam supply line 13.
Of course, in the apparatus provided with the steam ejector 4 as described above, the steam supply line 13 may be provided as a dedicated steam supply means 17 as the steam supply means 17 to the cooling tank 1.

Here, in the first embodiment described above, the second steam line 18 is connected to the upper part of the cooling tank 1 so as to supply steam from the upper part of the cooling tank 1. It is. Further, the vacuum suction line 2 is connected to a lower part of the cooling bath 1. Since steam has a lower specific gravity than air, when steam is supplied from the upper portion of the cooling tank 1 in this manner, air having a higher specific gravity than steam is pushed out from the lower portion of the cooling tank 1 by the steam. Can be discharged. Therefore, the cooling tank 1 can be filled with steam without leaving air therein,
Reliable sterilization can be performed.

[0027]

As described above, according to the vacuum cooling device of the present invention, steam sterilization is performed not only in the cooling tank but also in piping such as a vacuum suction line while the cooling operation of the vacuum cooling device is stopped. Therefore, the propagation of various bacteria can be reliably prevented, and the generation of offensive odor can also be prevented. Further, when the cooling operation is stopped, the cooling tank can be used as a sterilizer for sterilizing cooking utensils and the like, and as a storage. Therefore, the vacuum cooling device according to the present invention is excellent in hygiene, and does not generate an odor even when the vacuum cooling device is stopped for a long time.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of a first embodiment of a vacuum cooling device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cooling tank 2 Vacuum suction line 17 Steam supply means

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshiminami Tsubota Miura Kogyo Co., Ltd., 7-7, Horie-cho, Matsuyama-shi, Ehime Prefecture (72) Inventor Kumi Matsuya 7-Cho, Horie-cho, Matsuyama-shi, Ehime 72) Inventor Kiyoya Tateishi 7-Horiecho, Matsuyama-shi, Ehime Miura Industrial Co., Ltd.

Claims (1)

[Claims] 1. A vacuum cooling device, comprising: steam supply means 17 for supplying steam into a cooling tank 1 of the vacuum cooling device while the cooling operation of the vacuum cooling device is stopped.