JPH01107802A - Method and device for freeze concentration - Google Patents

Abstract

PURPOSE:To concentrate a large amt. of liq. food by freezing only the water contained in the liq. food on the surface of a heat exchanger, then melting and removing the ice. CONSTITUTION:A low-temp. medium is circulated through heat exchangers 21A-22B, and a raw liq. to be concd. is supplied into concentration tanks 61A-62B and brought into contact with the heat exchanger. The water in the raw liq. is frozen on the heat exchanger surface. The liq. concentrate is discharged from the concentration tank, and then a high-temp. medium is circulated through the heat exchanger instead of the low-temp. medium. As a result, the ice on the heat exchanger surface is melted into water, and discharged from the concentration tank. In addition, the raw liq. can be effectively cooled by directly spraying the raw liq. onto the heat exchanger surface.

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a concentration method and a concentration device for concentrating liquid foods (including beverages), and in particular to a concentration method and a concentration device for concentrating liquid foods (including beverages). The present invention relates to a method and apparatus for concentration by removal.

Conventional Technology In general, in the production of formal vinegar, the production of concentrated soups and sauces attached to instant noodles, cups, and other instant foods, and the production of concentrated fruit juice, the process of concentrating the stock solution, that is, the process of concentrating the stock solution, A process is required to remove as much moisture as possible from the When concentrating such liquid foods, it is often necessary to avoid deterioration due to heating, so vacuum evaporation concentration is generally used. However, vacuum evaporation S-condensation requires a high degree of vacuum, resulting in high running costs, and requires equipment to be airtight, resulting in high equipment costs.

Recently, attempts have been made to apply the freeze-concentration method to the concentration of liquid foods, but although the freeze-concentration method does not pose much of a problem for concentrating small amounts of liquid in experiments, it The reality is that it is not yet sufficient for continuous processing.

In other words, as an example of a method for concentrating a large amount of liquid food using the freeze concentration method, the stock solution to be concentrated is stored in advance in a concentration tank, and a cooling member cooled in advance to a low temperature is continuously poured into the stock solution in the concentration tank. The water in the stock solution is frozen on the surface of the cooling member by being immersed in the target or intermittently, and then the cooling member is continuously or intermittently pulled up from the concentration tank to remove the frozen water (ice) on the surface. One possible method is to remove it by melting, but in this case, the cooling member is pre-cooled outside the concentration tank and then immersed in the stock solution to freeze the moisture, so the cooling of the stock solution is indirect cooling, which reduces thermal efficiency. In addition to the problem of lowering the temperature and increasing costs, it also requires large-scale drive devices, chains, and
A conveyor or other auxiliary equipment is required, which poses problems such as high equipment costs and easy malfunction.In addition, special equipment is required to prevent the cooling medium used for pre-cooling the cooling components from entering the thickening tank. There are also problems that require consideration, and the reality is that no efficient method has yet been established for mass processing.

Problems to be Solved by the Invention As mentioned above, vacuum evaporation concentration, which has traditionally been widely used for concentrating liquid foods, has the problem of high running costs and equipment costs, while freezing'acondensation requires processing large amounts of liquid foods. Conventionally, when doing so, there has been no established method for efficient processing due to problems such as the thermal efficiency inevitably being low, or the drive mechanism for the cooling member being large-scale and frequently failing.

This invention was made against the background of the above-mentioned circumstances, and it has been made to apply the freeze-concentration method to concentrate liquid foods, and to make it possible to process large quantities efficiently, with simple equipment, and with fewer breakdowns. It is an object of the present invention to provide methods and apparatus.

Means for Solving the Problems The concentration method of the present invention basically consists of installing a heat exchanger through which a temperature medium flows inside the concentration tank, and flowing a low-temperature temperature medium through the heat exchanger. The undiluted solution to be concentrated is supplied into the concentration tank so as to be in contact with the heat exchanger, and the moisture in the undiluted solution is frozen on the surface of the heat exchanger, resulting in a water content lower than that of the undiluted solution. A concentrated liquid is obtained in a concentration tank, and after the concentrated liquid is discharged from the concentration tank to the outside, a high-temperature medium is passed through the heat exchanger to melt frozen water on the surface of the heat exchanger, It is characterized by being discharged from within the concentration tank.

Here, when supplying the stock solution into the 5JJt condensation tank, it is desirable to spray the stock solution toward the heat exchanger.

Furthermore, the freeze concentration device of the present invention includes a first concentration tank series consisting of one concentration tank or two or more concentration tanks connected in series, and a first concentration tank series consisting of one concentration tank or two or more concentration tanks connected in series. A second mt4 tank series is provided, each of the concentration tanks is provided with a heat exchanger through which a temperature medium flows, and a high temperature medium and a low temperature temperature medium are switched for each heat exchanger. This is characterized in that a temperature medium supply means is connected.

In the freeze concentration method of the first invention, a heat exchanger through which a temperature medium such as fluorocarbon flows is installed in the concentration tank,
In the first step, while a low-temperature medium is flowing through the heat exchanger, the stock solution to be concentrated is supplied into the concentration tank so as to be in contact with the heat exchanger. At this time, the stock solution to be concentrated is rapidly cooled when it comes into contact with the heat exchanger, and the water in the stock solution is frozen on the surface of the heat exchanger. Therefore, the water content in the stock solution decreases, and 1q of the condensed solution is reduced in the concentration tank. After the concentrated liquid obtained in this way is discharged from the concentration tank, the temperature medium flowing through the heat exchanger is changed, and a high temperature temperature medium is caused to flow in place of the low temperature temperature medium. As a result, the water, that is, ice that had been frozen on the surface of the heat exchanger in the previous step, is melted by the high temperature medium flowing through the heat exchanger, becomes liquid water, and is discharged from the concentration tank.

Here, when supplying the stock solution to be concentrated into the concentration tank, it is desirable to spray the stock solution directly onto the surface of the heat exchanger.By doing this, the stock solution is effectively rapidly cooled and water is sufficiently removed. It is possible to freeze it.

In the freeze concentrator of the second invention, there are two concentrator series: a first concentrator series consisting of one concentrator tank or two or more concentrator tanks connected in series, and a second concentrator series having a similar configuration. A series of tanks are provided, each of which is provided with a heat exchanger through which a heating medium flows. Here, if the stock solution to be subjected to yAM is supplied to the thickening tank of the first thickening tank series while a high-temperature medium is flowing through the heat exchanger of each thickening tank in the first thickening tank series, As already mentioned, the moisture in the stock solution freezes on the surface of the heat exchanger to obtain a concentrated solution. At this time, if the first thickening tank series is composed of two or more thickening tanks, the stock solution is supplied to the first thickening tank of the first thickening tank series, and The concentrated liquid (primary concentrated liquid) that has been concentrated to a certain extent can be supplied from the first concentration tank to the second concentration tank via a pump, and the concentration can proceed roughly. On the other hand, while concentration is being carried out in the first thickening tank series as described above, the supply and concentration of the stock solution is not performed in the second thickening tank series, and each thickening tank in the second thickening tank series is A high-temperature medium is passed through the heat exchanger to melt and remove frozen water (ice) on the surface of the heat exchanger. Conversely, while supplying and concentrating the stock solution in the second concentration tank series, the frozen moisture on the surface of the heat exchanger is thawed and removed in the first concentration tank series. Therefore, concentration and melting are repeated alternately in the first concentration tank series and the second concentration tank series.

EXAMPLE FIG. 1 shows an example of an apparatus for carrying out the freeze-concentration method of the first invention, that is, an example of the freeze-concentration apparatus of the second invention.

In FIG. 1, a stock solution tank 1 is for storing a stock solution 3 of brewed vinegar or other material to be treated, and a cooling pipe 2 is disposed within this stock solution tank 1. This cooling pipe 2 has a fluorocarbon liquid receiving tank 3 as described later.
Liquid Freon as a low-temperature medium is supplied from 1 to cool the stock solution 3 to some extent (pre-cooling). Note that the fluorocarbons coming out of the cooling pipe 2 are sent to a compressor 32, which will be described later.

The stock solution 3 in the stock solution tank 1 is guided to the first concentration tank 61A of the first concentration tank series 51 and the first concentration m62A of the second concentration tank series 52 via the stock solution supply pipes 41 and 42S. On-off valves 71 and 72 are provided in the middle of each stock solution supply pipe 41 and 42, respectively. In the example of FIG. 1, the first concentration tank series 51 includes two concentration tanks 61A,
61B, so that the liquid in the first 'a condensing tank 61A (corresponding to the primary concentrated liquid as described later) is guided to the second concentrating tank 61B via an intermediate communication pipe 81 and a pump 91. It has become. Therefore, within the first IN tank series 51, the first concentration tank 61A and the second concentration tank 61B are connected in series. Note that the liquid in the second concentration tank 61B (corresponding to a secondary concentrated liquid as described later) is led to the concentrated liquid tank 20 via a discharge pipe 101 and a pump 111. One way solution 2
The concentrating tank series 52 also consists of two concentrating tanks 62A and 62B, and the liquid (primary concentrated liquid) in the first 'a condensing tank 62A is transferred to the second concentrating tank 62A through the intermediate connecting pipe 82 and pump 92. Therefore, even in the second concentration tank series 52, the first and second concentration tanks 6
2A and 62B are connected in series. Note that also in this second concentration tank series 52, the second concentration tank 6
The liquid (secondary concentrated liquid) in 2B is led to the concentrated liquid tank 20 via a discharge pipe 102 and a pump 112.

In each of the concentration tanks 61A, 61B, 62A, 62B,
Heat exchangers 21A, 2'1B, 22A, and 22B are provided, respectively. These heat exchangers 21A to 22B have a temperature medium such as fluorocarbon flowing therein, and as shown in FIG. 2, for example, a plurality of tube bodies 23 arranged in parallel
The structure may be such that the tubes are connected in parallel and each tube body 23 is provided with a large number of fins 24, but it is of course not limited to this. Here, regarding the arrangement of each heat exchanger 21A to 22B, the first concentration tank 6 of each concentration tank series 51.52
The heat exchangers 21A and 122A in 1A and 62A are the heat exchangers 21 and 122A in which the stock solution 3 supplied from the stock solution supply pipe 41.42 is
The heat exchangers 21B and 22B in the second concentration tanks 61B and 62B of each S section tank series 51.52 are arranged so as to be in direct contact with the liquid ( The primary concentrated liquid) is transferred to the heat exchangers 21B and 22
Place it so that it is in direct contact with B. More preferably, the stock solution supply pipe 41.42 or the intermediate communication pipe 81.8
It is desirable that the undiluted solution or the primary #i rice liquid supplied from No. 2 is directly sprayed onto the surface of each of the heat exchangers 21A to 22B in an atomized state. for that,
In the example shown in Fig. 1, the concentrate 1 is placed above the m-part tanks 61A and 62A, so that the concentrate is sprayed into the concentration tanks 61A and 62A under considerable pressure due to its own weight. , and a pump 91. to the intermediate connecting pipe 81.82.
92 @ is installed and the primary concentrated liquid is transferred to the concentration tank 61 by the pump pressure.
B, 62B, but depending on the situation, a pump (not shown) may be provided in the middle of the stock solution supply pipes 41, 42, and the stock solution may be sprayed by the pump pressure. Moreover, it is desirable that each of the heat exchangers 21A to 22B is configured such that its vertical position can be changed within each concentration tank 61A to 62B.

A temperature medium supply means 30 for supplying a temperature medium such as fluorocarbon is connected to each of the heat exchangers 21A to 22B. This temperature medium supply means 30 supplies low temperature liquid Freon as a low temperature medium to the heat exchanger 21A121[3 of the first concentration tank series 51, and at the same time supplies the heat exchangers 22A and 22B of the second concentration tank series 52 with low temperature liquid fluorocarbon. A state in which high-temperature fluorocarbon gas as a high-temperature medium is supplied, and conversely, a state in which high-temperature fluorocarbon gas as a high-temperature medium is supplied to the heat exchangers 21A and 21B of the first concentrating tank series 51 and a state in which the second concentrating tank series 52 It is possible to alternately switch between two states: a state in which low-temperature liquid Freon is supplied as a low-temperature medium to the heat exchangers 22A and 22B. Specifically, the temperature medium supply means 30 includes a Freon receiving tank 31 that stores low-temperature liquid Freon, a compressor 32, water-cooled condensers 33 and 34 provided as necessary, and an on-off valve. 35A, 3
5B, 36A, 36B, 37A, 37B, 38A, 38
B, 39.

Next, how to use the example shown in FIG. 1 and the operation of each part will be explained.

First, concentration is performed in the first concentration tank series 51, and at the same time, in the second concentration tank series 52, the heat exchangers 22A, 2
FIG. 3 shows a state in which frozen water adhering to the surface of 2B is thawed. In Figure 3, the parts of the piping drawn with solid lines indicate the parts where the temperature medium (liquid fluorocarbon or fluorocarbon gas), stock solution, primary concentrated liquid, and secondary concentrated liquid are flowing, and the broken line parts are where these are flowing. Indicates the part that is not present.

It is assumed that before the stage shown in FIG. 3, moisture has already frozen and adhered to the surface of each heat exchanger 22A, 22B of the second concentration tank series 52.

In FIG. 3, on-off valve 71 is open and on-off valve 72 is closed. Therefore, the stock solution 3 in the stock solution tank 1 is supplied to the first concentration tank 61A of the first concentration tank series 51 via the on-off valve 71 and the stock solution supply pipe 41, whereas the stock solution 3 is supplied to the first concentration tank 61A of the first concentration tank series 51. is not supplied. On the other hand, in the temperature medium supply means 30, on-off valves 35A, 36A
, 37A, 38A are opened, and valves 35B, 36B, 3 are opened.
7B and 38B are closed. Therefore, Freon receiving tank 3
Low temperature liquid fluorocarbon is supplied to the heat exchangers 21A and 21B in each concentration tank 61A and 61B of the first concentration tank series 51 via the on-off valve 35A. Therefore, the first
1st tR:F of concentration tank series 51? In the third tank 61A, the stock solution is rapidly cooled on the surface of the heat exchanger 21, the water in the stock solution freezes and adheres to the heat exchanger 21A, and the water content in the stock solution decreases to become the primary concentrated solution 3A. This primary concentrated liquid 3A is guided to the second concentration tank 61B of the first concentration tank series 51 by an intermediate communication pipe 81 and a pump 91, and the water remaining in the primary concentrated liquid is removed from the heat exchanger 2'. It freezes and adheres to the surface of 1B, and the water content decreases roughly, becoming secondary concentrated liquid 3B. The secondary concentrated liquid 3B is led to the concentrated liquid tank 20 by a discharge pipe 101 and a pump 111.

In each of the heat exchangers 21A and 21B of the first concentration tank series 51, the low-temperature liquid fluorocarbon flowing therein is heat exchanged with the stock solution 3 or the primary concentrated solution 3A as described above and vaporized, resulting in fluorocarbon gas. Therefore, this fluorocarbon gas flows through the on-off valve 36.
It is led to the compressor 32 via A, and is compressed into high-temperature fluorocarbon gas.

This high-temperature fluorocarbon gas is passed through the on-off valve 38A to the heat exchanger 22 of each concentration tank 62A, 62B of the second concentration tank series 52.
A, 22B, the water (ice) frozen and adhering to the surface of the heat exchangers 22A, 22B is melted, becomes liquid water 3C, and is temporarily stored in each Wi-condenser tank 2A, 62B. After that, it is discharged through a discharge path (not shown) or immediately discharged.

In this way, the heat exchangers 62A, 6 of the second concentration tank series 52
In 2B, the high-temperature fluorocarbon gas flowing through it exchanges heat with the frozen moisture on the surface, and while the frozen moisture is melted, the fluorocarbon gas becomes low-temperature liquid fluorocarbon again. This low-temperature liquid Freon will return to the Freon receiving tank 31 via the on-off valve 37A, but depending on the case, the heat exchanger 22A, 22
In some cases, the high-temperature fluorocarbon gas does not return to liquid fluorocarbon gas sufficiently in step B. In that case, a water-cooled condenser 33 is provided as shown in the figure, and the condenser 33 roughly cools the fluorocarbon gas, liquefies it, and then transfers it to the fluorocarbon liquid receiving tank. Return to 31.

As mentioned above, in the state shown in FIG. 3, primary concentration and secondary concentration of the stock solution are performed in the first concentration tank series 51, and
Frozen moisture adheres to the heat exchangers 21A and 21B. Therefore, in the next step, contrary to the case shown in FIG.
, 21B to thaw the frozen moisture on the surface. The state is shown in FIG.

In FIG. 4, the on-off valve 71 is closed, while the on-off valve 72 is closed.
is opened and the concentrate in the concentrate tank 1 is transferred to the second concentration tank series 52.
is guided to the first yAN tank 62A. On the other hand, in the temperature medium supply means 30, on-off valves 35A, 36A, 37A
, 38A are closed, on-off valves 35B, 36B, 378, 38
8 is released.

Therefore, completely opposite to the case shown in FIG.
A, 22B is supplied with low-temperature liquid Freon via an on-off valve 35B, and the water content of the stock solution 3 or the primary concentrated solution 3A is frozen, that is, 'a-condensed' in the concentration tank 62A162B. The fluorocarbon gas gasified in the heat exchangers 62A and 62B is led to the compressor 32 via the on-off valve 36B, becomes high-temperature fluorocarbon gas, and passes through the on-off valve 38B to the first
It is guided to the heat exchangers 21A and 21B of each concentrating tank 61A and 61B of the a-part tank series 51. These heat exchangers 21A, 21
At B, the frozen water on the surface is melted and becomes liquid water 3C.
On the other hand, the fluorocarbon gas is either liquefied and returned to the fluorocarbon liquid receiving tank 31 via the on-off valve 37B, or liquefied by the water-cooled condenser 34 and returned to the fluorocarbon liquid receiving tank 31.

In this manner, in the state shown in FIG. 4, the frozen moisture on the surfaces of the heat exchangers 21A and 21B is removed in the first concentration tank series 51, while concentration is carried out in the second concentration tank series 52, and the heat exchanger Moisture adheres to and freezes on 22A122B. Therefore, after this, it is only necessary to operate again in the state shown in FIG. 3, and in this way, the first and second concentration tank series 5
By operating alternately at 1.52, a large amount of stock solution can be efficiently processed.

In the example shown in FIG. 1, preliminary cooling of the stock solution 3 in the stock solution tank 1 is also performed using freon. In other words, Freon receiving tank 3
The low-temperature liquid fluorocarbon from 1 is led to the cooling pipe 2 of undiluted solution 1 to preliminarily cool the undiluted solution 3, and the liquid fluorocarbon is gasified through heat exchange, and the fluorocarbon gas is passed through the compressor 32.
be led to.

In the above embodiment, since the heating (melting of frozen water) and cooling (concentration) by the heat exchangers 21A to 22B are performed using the same CFC, there is an advantage that the piping system is not contaminated by other media. In addition, since the same freon is recycled for heating and cooling, there is no need to install other heating means because waste heat is used, and there is also the advantage of saving energy, and the equipment configuration is generally simple. It has the advantage of easy maintenance and inspection, as well as fewer breakdowns.

In the example shown in Fig. 1, each thickening tank series 51, 52 is composed of two 'aN tanks, but depending on the case, only one tank may be used, or three or more tanks may be arranged in series. . Roughly speaking, in the example shown in FIG. 1, one heat exchanger is provided for each concentration tank, but depending on the case, heat exchangers may be arranged in multiple stages above and below. Roughly speaking, in the example shown in FIG. 1, the heat exchangers 21A to 22B are each connected to the concentration tank
Although they are installed independently inside the tanks A to 62B, in some cases a heat exchanger may be provided on the tank wall of the m section tanks 61A to 62B, or the tank wall of the concentration tank itself may be configured with a heat exchanger. Also good.

Effects of the Invention According to the freeze concentration method of the present invention, instead of concentrating by moving the cooling member as in the conventional method, the liquid to be concentrated is supplied and discharged to be concentrated, so the cooling member is moved. This eliminates the need for moving mechanisms such as drive devices, chains, and conveyors, which reduces equipment costs and reduces malfunctions.Also, because it is directly cooled and concentrated using a temperature medium, Compared to indirect cooling methods, thermal efficiency is higher and running costs are lower.Furthermore, unlike conventional methods, the cooling member is not cooled in advance, so there is no risk of the cooling medium being introduced into the concentrated liquid. However, it is also possible to obtain a high-quality liquid product.

Furthermore, according to the freezing concentration Wi apparatus of the present invention, concentration and thawing of frozen water are performed alternately in the first concentration tank series and the second S tank series, so that when processing a large amount of raw solution, In addition to being able to process efficiently with no time loss, the same temperature medium can be recycled for both cooling for concentration and thawing of frozen water, increasing energy usage efficiency. can get.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an example of an apparatus used in the freeze concentration method of the present invention, FIG. 2 is a plan view showing an example of a heat exchanger used in the apparatus of FIG. 1, and FIGS. FIG. 4 is a schematic diagram showing the usage state of the apparatus shown in FIG. 1, respectively. 3...Standard solution, 3A...Primary concentrated solution, 3B...
Secondary concentrated liquid, 3C...water, 21A, 21B, 22
A. 22B... Heat exchanger, 30... Temperature medium supply means, 51... First S section tank series, 52... Second concentration tank series, 61A, 61B, 62A, 62B... Concentrator tank. Applicant Hiroshino Hoshino Takumi Hara

Claims (3)

[Claims] (1) A heat exchanger through which a thermal medium flows is installed in the concentration tank, and the stock solution to be concentrated is brought into contact with the heat exchanger while a low-temperature thermal medium is flowing inside the heat exchanger. The moisture in the stock solution is then frozen on the surface of the heat exchanger to obtain a concentrate with a lower water content than the stock solution. After discharging it to the outside, a high temperature medium is passed through the heat exchanger to melt frozen moisture on the surface of the heat exchanger,
A freezing concentration method characterized by discharging water from the concentration tank. (2) The freeze concentration method according to claim 1, characterized in that when supplying the stock solution into the concentration tank, the stock solution is sprayed toward the surface of a heat exchanger. (3) A first thickening tank series consisting of one thickening tank or two or more thickening tanks connected in series, and a second thickening tank series consisting of one thickening tank or two or more thickening tanks connected in series. each of the concentration tanks is provided with a heat exchanger through which a temperature medium flows, and a temperature medium is supplied to each of the heat exchangers by switching between a high temperature medium and a low temperature temperature medium. A freeze concentration device characterized in that a means is connected thereto.