JP2022038035A - Liquid gas type spray freezing device - Google Patents

Abstract

To provide a liquid gas type spray freezing device which can stably manufacture a freeze object.SOLUTION: A liquid gas type spray freezing device 1 includes a cooling tank 2 which sprays a raw material and a low temperature liquid gas to freeze the raw material, a raw material supply passage L1 which supplies the raw material to the cooling tank 2, a low temperature liquid gas supply passage L2 which supplies the low temperature liquid gas to the cooling tank 2, and a gas liquid separator 3 which is located in the low temperature liquid gas supply passage L2 and separates the low temperature liquid gas into gas and liquid.SELECTED DRAWING: Figure 1

Description

The present invention relates to a liquefied gas spray freezing device.

As a device for freezing a liquid raw material such as food, a liquefied gas type spray freezing device using the cold heat of a low-temperature liquefied gas such as liquid nitrogen or liquid argon sprayed in the form of a mist is known.
For example, Patent Document 1 discloses a method of supplying an object to be frozen and a cryogen which is a sterile liquefied gas into a cooling tank from individual nozzles, and a spray freezing device.
Further, Patent Document 2 discloses a method of supplying frozen particles and a cryogen (ultra-low temperature liquid) into a cooling tank from individual nozzles to produce frozen particles, and a spray freezing device.

Japanese Patent No. 5837670 Japanese Unexamined Patent Publication No. 6-323712

However, in the spray freezing device described in Patent Documents 1 and 2, the temperature in the cooling tank may become unstable or the temperature in the cooling tank may not be sufficiently lowered, so that the object to be frozen is stable. There was a problem that it could not be manufactured. Therefore, it was necessary to increase the size of the spray freezing device more than necessary and to supply an excessive amount of liquefied gas.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a liquefied gas type spray freezing device capable of stably producing an object to be frozen.

Generally, liquefied gas is stored in a supply facility such as a liquefied gas storage tank in a high pressure state, and is transferred from the supply facility to the place of use by self-pressure via a supply pipe such as a vacuum double pipe.
The inventors of the present application pulsate the liquefied gas by being supplied in a gas-liquid two-phase flow when the distance of the supply pipe from the supply facility to the place of use is long or there are many branches. The present invention has been completed by finding out that the temperature inside the cooling tank may become unstable or the temperature inside the cooling tank may not be sufficiently lowered because the spray freezing device cannot be stably supplied in a liquid state. rice field.

In order to solve the above problems, the present invention has the following configurations.
[1] A liquefied gas type spray freezing device that freezes the raw material by exchanging heat between the liquid raw material and the low temperature liquefied gas.
A cooling tank that sprays the raw material and the cryogenic liquefied gas to freeze the raw material,
A raw material supply path for supplying the raw material to the cooling tank, and
A cryogenic gas supply path for supplying the cryogenic liquefied gas to the cooling tank,
A liquefied gas type spray freezing device, which is located in the low temperature liquefied gas supply path and includes a gas-liquid separator for gas-liquid separation of the low-temperature liquefied gas.
[2] The above-mentioned item [1], which is located between the gas-liquid separator and the cooling tank and includes a vaporization gas supply path for supplying the vaporized gas separated by the gas-liquid separator to the cooling tank. Liquefied gas spray freezing device.
[3] The liquefied gas type spray freezing device according to the preceding item [2], which is located in the vaporized gas supply path and includes a pressure control mechanism for controlling the pressure in the gas-liquid separator.
[4] The pressure control mechanism receives signals from the pressure measuring device for measuring the pressure in the gas-liquid separator, the pressure control valve located in the vaporized gas supply path, and the pressure measuring device. The liquefied gas type spray freezing device according to the preceding item [3], comprising a pressure regulator for transmitting a signal to a pressure control valve.
[5] The liquefied gas according to any one of the preceding items [1] to [4], which is located in the cryogenic gas supply path and includes a flow rate control mechanism for controlling the supply amount of the cryogenic liquefied gas to the cooling tank. Type spray freezing device.
[6] The flow rate control mechanism includes a flow rate regulator that determines the supply amount of the low temperature liquefied gas, and a flow rate control valve located in the low temperature liquefied gas supply path on the secondary side of the gas-liquid separator. , The liquefied gas type spray freezing device according to the preceding item [5].
[7] The liquefied gas type spray freezing device according to any one of the preceding items [1] to [6], comprising a liquid level control mechanism for controlling the position of the liquid level of the cryogenic liquefied gas in the gas-liquid separator.
[8] The liquid level control mechanism is connected to a liquid level sensor that detects the position of the liquid level of the low temperature liquefied gas in the gas and liquid separator and the low temperature liquefied gas supply path on the primary side of the gas and liquid separator. The liquefied gas type spray freezing according to the preceding item [7], comprising a liquid level control valve located and a liquid level controller that receives a signal from the liquid level sensor and transmits a signal to the liquid level control valve. Device.

The liquefied gas spray freezing device of the present invention can stably produce an object to be frozen.

It is a system diagram which shows the structure of the liquefied gas type spray freezing apparatus which is one Embodiment of this invention.

Hereinafter, the liquefied gas type spray freezing device according to the embodiment to which the present invention is applied will be described in detail with reference to the drawings together with the operation method thereof. In addition, in the drawings used in the following explanation, in order to make the features easy to understand, the featured parts may be enlarged for convenience, and the dimensional ratios of each component may not be the same as the actual ones. do not have.

<Liquefied gas spray freezing device>
First, an example of the configuration of a liquefied gas type spray freezing device according to an embodiment to which the present invention is applied will be described. FIG. 1 is a system diagram showing the configuration of the liquefied gas type spray freezing device 1 of the present embodiment.
The liquefied gas type spray freezing device 1 of the present embodiment is a device that heat-exchanges a liquid raw material with a low-temperature liquefied gas such as liquid nitrogen or liquid argon to turn the raw material into a fine-grained frozen product.
As shown in FIG. 1, the liquefied gas type spray freezing device 1 of the present embodiment has a cooling tank 2, a gas / liquid separator 3, a raw material supply path L1, a low temperature liquefied gas supply path L2, a vaporized gas supply path L3, and a gas / liquid. The position of the pressure control mechanism 4 that controls the pressure in the separator 3, the flow control mechanism 5 that controls the supply amount of the low-temperature liquefied gas to the cooling tank 2, and the liquid level of the low-temperature liquefied gas in the gas-liquid separator 3. A liquid level control mechanism 6 for controlling is provided.

The cooling tank 2 is a closed container that freezes the raw material by spraying the raw material and the low-temperature liquefied gas into the tank.
The cooling tank 2 has a heat insulating structure from the viewpoint of suppressing the temperature rise in the cooling tank 2 due to the invading heat from the outside air as much as possible. As the heat insulating structure, a vacuum heat insulating structure is preferable.

The raw material supply path L1, the cryogenic liquefied gas supply path L2, and the vaporized gas supply path L3 are connected to the cooling tank 2, respectively.

The raw material supply path L1 penetrates the upper part of the cooling tank 2. The raw material supply port (raw material input port) at the tip of the raw material supply path L1 is open in the cooling tank 2, and the liquid raw material can be supplied into the cooling tank 2. Further, a nozzle 7 for spraying the raw material downward into the cooling tank 2 is arranged at the raw material supply port. The nozzle 7 is not particularly limited as long as it sprays the raw material into the cooling tank 2, and can be appropriately selected according to the raw material to be supplied, such as a spray nozzle.

A low-temperature liquefied gas supply path L2 penetrates the bottom of the cooling tank 2. The cryogenic gas supply port (low temperature liquefied gas input port) at the tip of the low temperature liquefied gas supply path L2 is open in the cooling tank 2, and the low temperature liquefied gas can be supplied into the cooling tank 2. Further, a spray nozzle (not shown) for spraying the cryogenic gas upward into the cooling tank 2 is arranged at the cryogenic gas supply port.

According to the liquefied gas type spray freezing device 1 of the present embodiment, the raw material is sprayed downward from the upper part of the cooling tank 2 and the low temperature liquefied gas is sprayed upward from the bottom of the cooling tank 2 in the cooling tank 2. The liquid raw material and the low-temperature liquefied gas exchange heat, and the raw material becomes a finely divided frozen product.

Further, a vaporization gas supply path L3 penetrates the upper part of the cooling tank 2. The vaporization gas supply port (vaporization gas input port) at the tip of the vaporization gas supply path L3 is open in the cooling tank 2, and the vaporization gas in a low temperature state can be supplied into the cooling tank 2.

A temperature measuring device (temperature sensor) 8 for measuring the temperature inside the cooling tank 2 is arranged near the center of the cooling tank 2.
Further, a temperature measuring device (temperature sensor) 9 for measuring the temperature of the frozen material of the raw material is arranged at the bottom of the cooling tank 2.
According to the liquefied gas type spray freezing device 1 of the present embodiment, the raw material can be supplied to the cooling tank 2 from the nozzle 7 after confirming that the inside of the cooling tank 2 is stable at a predetermined temperature.

Further, at the bottom of the cooling tank 2, a recovery facility (not shown) such as a rotary valve for recovering frozen raw materials is arranged. From the viewpoint of preventing the frozen material from being thawed, it is preferable that the recovery equipment keeps the inside of the equipment in a low temperature and dry state.

The raw material supply path L1 is located between the raw material tank 10 and the cooling tank 2, which are the raw material supply sources. The base end of the raw material supply path L1 is connected to the raw material tank 10. As a result, the raw material can be supplied from the raw material tank 10 to the cooling tank 2 via the raw material supply path L1.
Examples of the raw material supply path L1 include a pipe capable of transferring a liquid raw material.

In the raw material supply path L1, a raw material supply pump 11 for transferring the raw material and an inverter 12 for controlling the rotation speed of the raw material supply pump 11 are arranged. Thereby, by controlling the rotation speed of the raw material supply pump 11 by the inverter 12, the amount of the raw material supplied to the cooling tank 2 can be changed.

The raw material tank 10 includes a temperature measuring device (temperature sensor) 13 that measures the temperature of the raw material in the raw material tank 10, a temperature controller 14 that receives a signal from the temperature sensor 13 and controls the temperature, and a temperature controller 14. A heater 15 that operates in response to the ON / OFF signal of the above is arranged. As a result, the raw material tank 10 and the raw material supply path L1 can be maintained at a temperature equal to or higher than the freezing point of the raw material, and solidification of the raw material during storage and transfer can be prevented.

The cryogenic gas supply path L2 is located between the cryogenic gas supply source 16 and the cooling tank 2. The base end of the cryogenic gas supply path L2 is connected to the cryogenic gas supply source 16. As a result, the low-temperature liquefied gas can be supplied from the low-temperature liquefied gas supply source 16 to the cooling tank 2 via the low-temperature liquefied gas supply path L2.
Examples of the low-temperature liquefied gas supply path L2 include pipes capable of transferring low-temperature liquefied gas.

In the liquefied gas type spray freezing device 1 of the present embodiment, a gas-liquid separator 3 for gas-liquid separation of the low-temperature liquefied gas is arranged in the low-temperature liquefied gas supply path L2. In other words, the cryogenic gas supply path L2 is a low temperature liquefied gas supply path L2A on the primary side (upstream side) of the gas-liquid separator 3 and a low-temperature liquefied gas supply on the secondary side (downstream side) of the gas-liquid separator 3. It is composed of a path L2B.

The cryogenic gas supply path L2A is located between the cryogenic gas supply source 16 and the gas-liquid separator 3. The base end of the cryogenic gas supply path L2A is connected to the cryogenic gas supply source 16. The tip of the cryogenic gas supply path L2A is open to the gas phase 3A portion in the gas-liquid separator 3. As a result, the cryogenic gas can be supplied from the cryogenic gas supply source 16 into the gas-liquid separator 3 via the cryogenic gas supply path L2A.

The cryogenic gas supply path L2B is located between the gas-liquid separator 3 and the cooling tank 2. The base end of the cryogenic gas supply path L2B is connected to the liquid phase 3B portion in the gas-liquid separator 3. The tip of the cryogenic gas supply path L2B is open in the cooling tank 2. As a result, the low-temperature liquefied gas can be stably supplied in the liquid state from the liquid phase 3B portion of the gas-liquid separator 3 into the cooling tank 2 via the low-temperature liquefied gas supply path L2B.

The gas-liquid separator 3 is a closed container located in the low-temperature liquefied gas supply path L2 and for gas-liquid separation of the low-temperature liquefied gas introduced from the low-temperature liquefied gas supply source 16.
The gas-liquid separator 3 has a heat insulating structure from the viewpoint of suppressing the vaporization of the low-temperature liquefied gas in the gas-liquid separator 3 as much as possible. As the heat insulating structure, a vacuum heat insulating structure is preferable.

The low temperature liquefied gas is stored in the gas-liquid separator 3. The low-temperature liquefied gas in the gas-liquid separator 3 is separated into a gas phase 3A composed of a low-temperature vaporized gas and a liquid phase 3B composed of a low-temperature liquefied gas in a liquid state. The position of the liquid level of the low-temperature liquefied gas, which is the interface between the gas phase 3A and the liquid phase 3B, is controlled to be within a predetermined range by the liquid level control mechanism 6 described later.

A low-temperature liquefied gas supply path L2A, a low-temperature liquefied gas supply path L2B, and a vaporization gas supply path L3 are connected to the gas-liquid separator 3, respectively.

A low-temperature liquefied gas supply path L2A penetrates the upper part of the gas-liquid separator 3. The low-temperature liquefied gas introduction port (low-temperature liquefied gas receiving port) at the tip of the low-temperature liquefied gas supply path L2A is open to the gas phase 3A portion in the gas-liquid separator 3, and is liquefied from the low-temperature liquefied gas supply source 16. The gas can be supplied into the gas-liquid separator 3.

A low temperature liquefied gas supply path L2B penetrates the bottom of the gas-liquid separator 3. The low-temperature liquefied gas outlet (low-temperature liquefied gas discharge port), which is the base end of the low-temperature liquefied gas supply path L2B, is open to the liquid phase 3B portion in the gas-liquid separator 3 and is in a liquid state from the gas-liquid separator 3. The low temperature liquefied gas can be supplied into the cooling tank 2.

According to the liquefied gas type spray freezing device 1 of the present embodiment, the low-temperature liquefied gas supplied from the low-temperature liquefied gas supply source 16 is gas-liquid due to the configuration in which the gas-liquid separator 3 is arranged in the low-temperature liquefied gas supply path L2. Even in a two-phase flow state or a plug flow state, the gas-liquid separator 3 separates the gas and liquid, so that the low-temperature liquefied gas in the liquid state can be stably supplied into the cooling tank 2.

Further, a vaporized gas supply path L3 penetrates the upper part of the gas-liquid separator 3. The vaporization gas outlet (vaporization gas supply port), which is the base end of the vaporization gas supply path L3, is open to the gas phase 3A portion in the gas-liquid separator 3, and the vaporization gas in a low temperature state is opened from the gas-liquid separator 3. Can be supplied into the cooling tank 2.

In the gas-liquid separator 3, the low-temperature liquefied gas inlet and the vaporized gas outlet are arranged at positions higher than the upper limit set as the liquid level position of the low-temperature liquefied gas. Further, the low temperature liquefied gas outlet is arranged at a position lower than the lower limit value set as the liquid level position of the low temperature liquefied gas.

The vaporization gas supply path L3 is located between the gas-liquid separator 3 and the cooling tank 2, and supplies the low-temperature vaporized gas separated by the gas-liquid separator 3 to the cooling tank 2.
Examples of the vaporized gas supply path L3 include pipes capable of transferring the vaporized gas. Further, the vaporized gas supply path L3 preferably has a heat insulating structure from the viewpoint of effectively utilizing the cold heat of the vaporized gas.

The vaporized gas supply path L3 branches off from the discharge path L4 at the branch point P.
A pressure reducing valve 17 and a flow meter 18 are arranged on the secondary side of the branch point P of the vaporization gas supply path L3. Thereby, the pressure and the flow rate of the vaporized gas supplied to the cooling tank 2 can be adjusted.

The discharge path L4 branches from the vaporized gas supply path L3 at the branch point P, and supplies a part or all of the vaporized gas flowing through the vaporized gas supply path L3 to another facility 19 such as a buffer tank. As a result, the vaporized gas can be effectively used.
Examples of the discharge path L4 include piping capable of transferring vaporized gas. Further, the discharge path L4 may have a heat insulating structure from the viewpoint of effectively utilizing the cold heat of the vaporized gas, and may not have a heat insulating structure when the vaporized gas is used at room temperature.
A check valve 20 is arranged in the discharge path L4. This makes it possible to prevent the backflow of the vaporized gas from the other equipment 19.

The pressure control mechanism 4 is located in the vaporization gas supply path L3 and adjusts so as to keep the pressure in the gas-liquid separator 3 as low as possible. The pressure control mechanism 4 includes a pressure transmitter (pressure measuring device) 21, a pressure control valve 22, and a pressure regulator 23.

The pressure transmitter 21 measures the pressure in the gas-liquid separator 3. The pressure transmitter 21 may be arranged so as to communicate with the gas phase 3A portion of the gas-liquid separator 3 or communicate with the primary side (upstream side) of the pressure control valve 22 of the vaporization gas supply path L3. It may be arranged.
The pressure control valve 22 is located on the primary side (upstream side) of the branch point P of the vaporization gas supply path L3.
The pressure regulator 23 receives a signal of the pressure measurement value from the pressure transmitter 21 and transmits a signal for controlling the opening degree to the pressure control valve 22. The pressure transmitter 21 and the pressure regulator 23 may be integrated.

In the liquefied gas type spray freezing device 1 of the present embodiment, the pressure control valve 22 is opened when the pressure value in the gas-liquid separator 3 exceeds a preset upper limit value, and the pressure control valve 22 is opened when the pressure value is less than the lower limit value. 22 is closed. In this way, by maintaining the pressure in the gas-liquid separator 3 in a low state by the pressure control mechanism 4, the temperature of the low-temperature liquefied gas in the gas-liquid separator 3 can be lowered, so that the low-temperature liquefied gas supply path. When supplied to the cooling tank 2 via L2 (L2B), the flash loss of the low temperature liquefied gas can be reduced.

It is preferable that the pressure in the gas-liquid separator 3 is controlled in the range of 0.1 to 0.2 MPaG by the pressure control mechanism 4.
By setting the pressure in the gas-liquid separator 3 to 0.1 MPaG or more, the pressure in the gas-liquid separator 3 approaches atmospheric pressure, so that the flash loss of the low-temperature liquefied gas can be reduced. In addition, it is possible to secure a pressure for spraying the cryogenic liquefied gas from the nozzle in the form of mist.
By setting the pressure in the gas-liquid separator 3 to 0.2 MPaG or less, even if a pressure loss occurs in the low-temperature liquefied gas supply path L2 (L2B) from the gas-liquid separator 3 to the cooling tank 2, the cooling tank 2 Low temperature liquefied gas can be reliably supplied to.

The flow rate control mechanism 5 is located in the low temperature liquefied gas supply path L2 (that is, the low temperature liquefied gas supply path L2B) on the secondary side of the gas-liquid separator 3, and the low-temperature liquefied gas from the gas-liquid separator 3 to the cooling tank 2. Control the supply of gas. The flow rate control mechanism 5 includes a flow rate regulator 24 and a flow rate control valve 25.

The flow rate controller 24 determines the amount of low-temperature liquefied gas supplied from the gas-liquid separator 3 to the cooling tank 2.
The flow rate control valve 25 is located in the low temperature liquefied gas supply path L2 (that is, the low temperature liquefied gas supply path L2B) on the secondary side of the gas-liquid separator 3.

Further, a pressure measuring device 26 and a safety valve 27 are arranged in the low temperature liquefied gas supply path L2B. As a result, when the pressure of the cryogenic liquefied gas in the cryogenic gas supply path L2B rises abnormally, it can be released to the outside of the system.

In the liquefied gas type spray freezing device 1 of the present embodiment, the low temperature liquefied gas can be quantitatively supplied from the gas-liquid separator 3 to the cooling tank 2 by the flow rate control mechanism 5.

The liquid level control mechanism 6 controls the position (height) of the liquid level of the cryogenic liquefied gas in the gas-liquid separator 3 so as to be as constant as possible. The liquid level control mechanism 6 includes a liquid level sensor (liquid level gauge) 28, a liquid level control valve 29, and a liquid level regulator 30.

The liquid level sensor 28 is located in the gas-liquid separator 3 and detects the position of the liquid level of the cryogenic liquefied gas in the gas-liquid separator 3.
The liquid level control valve 29 is located in the low temperature liquefied gas supply path L2 (that is, the low temperature liquefied gas supply path L2A) on the primary side of the gas-liquid separator 3.
The liquid level regulator 30 receives a signal of the liquid level measured value from the liquid level sensor 28, and transmits a signal for controlling the opening degree to the liquid level control valve 29. The liquid level sensor 28 and the liquid level adjuster 30 may be integrated.

In the liquefied gas type spray freezing device 1 of the present embodiment, the liquid level control valve 29 is opened when the position of the liquid level in the gas-liquid separator 3 is less than the preset lower limit value, and when the upper limit value is exceeded. The liquid level control valve 29 is closed. In this way, by maintaining the position of the liquid level of the low-temperature liquefied gas in the gas-liquid separator 3 to be constant by the liquid level control mechanism 6, a certain amount of the low-temperature liquefied gas is separated into gas and liquid. Since it can be stored in the liquid separator 3, the low-temperature liquefied gas in a liquid state can be stably supplied to the cooling tank 2 via the low-temperature liquefied gas supply path L2 (L2B).
Therefore, in the liquefied gas type spray freezing device 1 of the present embodiment, the temperature in the cooling tank 2 is sufficiently lowered and the temperature in the cooling tank 2 is stabilized, so that the granular frozen material (freezing material) is stable. Can be manufactured.

<How to operate the liquefied gas spray freezing device>
Next, an example of the operation method of the liquefied gas type spray freezing device 1 described above (that is, the spray freezing method using the liquefied gas type spray freezing device 1) will be described.

First, the following operating conditions are set before starting the operation of the liquefied gas type spray freezing device 1.
-In the inverter 12, the rotation speed of the raw material supply pump 11 is set.
-In the temperature controller 14, the upper limit value and the lower limit value of the temperature of the heater 15 that heats the raw material tank 10 and the raw material supply path L1 are set.
-In the liquid level regulator 30, the upper limit value and the lower limit value of the liquid level position of the cryogenic liquefied gas in the gas-liquid separator 3 are set.
-In the flow rate regulator 24, the opening degree of the flow rate control valve 25 is set.
-In the pressure regulator 23, the upper limit value and the lower limit value of the pressure in the gas-liquid separator 3 are set.
The pressure and flow rate of the vaporized gas supplied to the cooling tank 2 are set in the pressure reducing valve 17 and the flow meter 18, respectively.

Next, the operation of the liquefied gas type spray freezing device 1 is started in the following order.
-The low-temperature liquefied gas is supplied from the low-temperature liquefied gas supply source 16 into the gas-liquid separator 3 via the low-temperature liquefied gas supply path L2A, and the low-temperature liquefied gas is gas-liquid separated in the gas-liquid separator 3.
-A liquid low-temperature liquefied gas is quantitatively supplied into the cooling tank 2 from the liquid phase 3B portion in the gas-liquid separator 3.
After the temperatures of the raw material tank 10 and the raw material supply path L1 are stable above the freezing point of the raw material and the temperature inside the cooling tank 2 is stable at a low temperature (for example, −140 to −160 ° C.), the raw material supply pump 11 Is started to supply the raw material into the cooling tank 2.
-The fine particle-like frozen matter accumulated in the lower part of the cooling tank 2 is recovered by the recovery equipment (not shown).

As described above, according to the liquefied gas type spray freezing device 1 of the present embodiment, the gas-liquid separator 3 is connected to the low-temperature liquefied gas supply path L2 for supplying the low-temperature liquefied gas from the low-temperature liquefied gas supply source 16 to the cooling tank 2. Is arranged, the gas-liquid separation is performed in the gas-liquid separator 3 even if the low-temperature liquefied gas supplied from the low-temperature liquefied gas supply source 16 is in a gas-liquid two-phase flow state or a plug flow state. Therefore, the low-temperature liquefied gas in a liquid state can be stably supplied into the cooling tank 2. Therefore, the temperature inside the cooling tank 2 is sufficiently lowered and the temperature inside the cooling tank 2 is stabilized, so that a granular frozen product (object to be frozen) can be stably produced without supplying an excessive amount of low-temperature liquefied gas. can.

By the way, due to the characteristics of liquefied gas, the higher the pressure, the larger the flash loss (loss due to pressure fluctuation). Therefore, in the conventional liquefied gas type spray freezing device, the cryogenic liquefied gas cannot be supplied to the cooling tank in a low pressure state, and it is necessary to supply the liquefied gas in excess.

On the other hand, according to the liquefied gas type spray freezing device 1 of the present embodiment, the cooling tank 2 is provided with a pressure control mechanism 4 for adjusting the pressure in the gas-liquid separator 3 so that the low-temperature liquefied gas is in a low pressure state. Since it can be supplied to, flash loss can be reduced.

Further, according to the liquefied gas type spray freezing device 1 of the present embodiment, the amount of low temperature liquefied gas used can be optimized and the flash loss can be reduced, so that the size and cost can be reduced as compared with the conventional spray freezing device. Is possible.

Although the embodiments of the present invention have been described above, the present invention is not limited to such specific embodiments. In addition, the present invention may be added, omitted, replaced, or otherwise modified within the scope of the gist of the present invention described in the claims.

In the liquefied gas type spray freezing device 1 of the above-described embodiment, the raw material supply port is arranged above the cooling tank 2, the raw material is sprayed downward in the cooling tank 2, and the low temperature liquefied gas supply port is the cooling tank. Although the configuration in which the low temperature liquefied gas is arranged at the bottom of the 2 and the low temperature liquefied gas is sprayed upward in the cooling tank 2 has been described as an example, the present invention is not limited to this. For example, both the raw material supply port and the low-temperature liquefied gas supply port may be arranged above the cooling tank 2 and sprayed downward into the cooling tank 2, respectively, or the raw material supply port and the low-temperature liquefied gas supply port may be configured. May be arranged at the bottom of the cooling tank 2 and sprayed upward into the cooling tank 2.

Hereinafter, the effects of the present invention will be described in detail with reference to verification examples. The present invention is not limited to the contents of the following verification examples.

<Verification example 1>
The accuracy of temperature control of the low temperature liquefied gas supply port in the cooling tank depending on the presence or absence of the gas-liquid separator is described below. The temperature control accuracy is the difference between the minimum temperature and the maximum temperature of the low temperature liquefied gas supply port during no-load operation.
The effects obtained by the present invention are described.
(1) With gas-liquid separator: Approximately 2 ° C (the temperature inside the cooling tank is stable)
(2) Without gas-liquid separator: Approximately 40 ° C (the temperature inside the cooling tank is unstable)

<Verification example 2>
The amount of reduction in flash loss when the supply pressure of the cryogenic liquefied gas to the cooling tank is 0.6 MPa and when the pressure is 0.1 MPa is described below. The amount of reduction in flash loss is based on theoretical calculation.
(1) When the supply pressure is 0.6 MPa: 23%
(2) When the supply pressure is 0.1 MPa: 7%
As described above, when the supply pressure is 0.1 MPa, the effect of reducing the flash loss by 16% is expected as compared with the case of 0.6 MPa.

1 ... Liquefied gas spray freezing device 2 ... Cooling tank 3 ... Gas-liquid separator 3A ... Gas phase 3B ... Liquid phase 4 ... Pressure control mechanism 5 ... Flow control mechanism 6 ... Liquid level control mechanism 7 ... Nozzle 8, 9 ... Temperature measuring instrument (temperature sensor)
10 ... Raw material tank 11 ... Raw material supply pump 12 ... Inverter 13 ... Temperature measuring instrument (temperature sensor)
14 ... Temperature controller 15 ... Heater 16 ... Low temperature liquefied gas supply source 17 ... Pressure reducing valve 18 ... Flow meter 19 ... Other equipment 20 ... Check valve 21 ... Pressure transmitter (pressure measuring instrument)
22 ... Pressure control valve 23 ... Pressure regulator 24 ... Flow rate regulator 25 ... Flow control valve 26 ... Pressure measuring device 27 ... Safety valve 28 ... Liquid level sensor (liquid level) Total)
29 ... Liquid level control valve 30 ... Liquid level regulator L1 ... Raw material supply path L2, L2A, L2B ... Cryogenic liquefied gas supply path L3 ... Vaporized gas supply path L4 ... Discharge path P ... Branch point

Claims (8)

A liquefied gas type spray freezing device that freezes the raw material by exchanging heat between the liquid raw material and the low temperature liquefied gas.
A cooling tank that sprays the raw material and the cryogenic liquefied gas to freeze the raw material, and
A raw material supply path for supplying the raw material to the cooling tank, and
A cryogenic gas supply path for supplying the cryogenic liquefied gas to the cooling tank,
A liquefied gas type spray freezing device, which is located in the low temperature liquefied gas supply path and includes a gas-liquid separator for gas-liquid separation of the low-temperature liquefied gas. The liquefied gas type according to claim 1, which is located between the gas-liquid separator and the cooling tank and includes a vaporized gas supply path for supplying the vaporized gas separated by the gas-liquid separator to the cooling tank. Spray freezing device. The liquefied gas type spray freezing device according to claim 2, which is located in the vaporized gas supply path and includes a pressure control mechanism for controlling the pressure in the gas-liquid separator. The pressure control mechanism includes a pressure measuring device that measures the pressure in the gas-liquid separator, a pressure control valve located in the vaporization gas supply path, and the pressure control valve that receives a signal from the pressure measuring device. The liquefied gas type spray freezing device according to claim 3, further comprising a pressure regulator for transmitting a signal to the device. The liquefied gas type spray freezing device according to any one of claims 1 to 4, which is located in the cryogenic gas supply path and includes a flow rate control mechanism for controlling the supply amount of the cryogenic gas to the cooling tank. .. The flow rate control mechanism includes a flow rate regulator that determines the supply amount of the low temperature liquefied gas, and a flow rate control valve located in the low temperature liquefied gas supply path on the secondary side of the gas-liquid separator. The liquefied gas type spray freezing device according to 5. The liquefied gas type spray freezing device according to any one of claims 1 to 6, further comprising a liquid level control mechanism for controlling the position of the liquid level of the cryogenic liquefied gas in the gas-liquid separator. The liquid level control mechanism includes a liquid level sensor that detects the position of the liquid level of the low-temperature liquefied gas in the gas-liquid separator, and a liquid located in the low-temperature liquefied gas supply path on the primary side of the gas-liquid separator. The liquefied gas spray freezing device according to claim 7, further comprising a surface control valve and a liquid level regulator that receives a signal from the liquid level sensor and transmits a signal to the liquid level control valve.

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