JPH067884B2 - Pressurized freeze concentrator - Google Patents

Description

TECHNICAL FIELD The present invention relates to a pressurization type freeze concentration apparatus for producing various kinds of beverages, chemicals, and other concentrated solutions.

[Prior Art] A solution containing a solute and a solvent (water) is once frozen to form an ice crystal, and the ice crystal is pressurized to separate a solution having a high solute concentration from the ice crystal to produce a concentrated solution. A so-called pressurization type freeze concentration device has been known for some time.

These devices utilize the physical phenomenon that the freezing point (freezing point) of a solution changes depending on the solute concentration with respect to the solvent (water) and the pressure applied to the solution.

For example, in the case of an aqueous solution, the freezing point is lowered by pressurization, and the freezing point is also lowered due to the high concentration of solute contained in the aqueous solution.

As shown in the system diagram of the previous apparatus according to FIG. 2, the raw material liquid 32 injected into the mother liquor container 31 by the pump P naturally drops into the cooling cylinder 33.

Then, the raw material liquid 32 is cooled and frozen by the cooling medium 39 that enters from the inflow port 34a of the jacket 34 in the cooling cylinder 33, exits from the outflow port 34b, and circulates, and becomes ice crystals 36.

This ice crystal 36 is pulled downward by the pulling body 37, passes through the heat insulating portion 35, and is pressed into a pressurizing cylinder 38 having a tapered hole with a narrowed lower portion and is pressurized.

Further, an inlet 41a of a jacket 41 provided in the pressurizing cylinder 38
Ice crystal 36 by the cooling medium 40 having a temperature slightly higher than that of the cooling medium 39 which is circulated from the outlet 41b and circulated from the outlet 41b.
Is heated to lower the freeze hardness. This gives ice crystals 36
The concentrated liquid 44 having a higher solute concentration is melted and separated, and flows out to the discharge pipe 43 through the pocket 42.

However, in the above device, the cooling cylinder
Due to the poor thermal conductivity in 33, the ice crystals 36 are not sufficiently cooled in the radial direction, and the freezing hardness in the vicinity of the traction body 37 is insufficient. Therefore, in the prior art, the diameter of the cooling cylinder inner tube is made extremely small in order to prevent the variation in the freezing hardness of the ice crystals 36 in the radial direction. In this case, the amount of ice crystals 36 press-fitted into the pressurizing cylinder 38 was reduced, and the amount of concentrated liquid to be separated was small, and the processing capacity was low.

[Object of the Present Invention] The present invention has a large radius of ice crystals formed in the cooling cylinder, and by uniformly equalizing the ice hardness in the radial direction in the ice crystals, the ice crystals are pressed into the pressurizing cylinder. It is possible to provide a pressurizing type freeze-concentrating device having a high processing capacity, which increases the amount of ice crystals contained in the pressurizing cylinder and satisfactorily melts the ice crystals in the pressurizing cylinder to effectively separate and produce a concentrated liquid.

[Means for Solving the Problems] In order to solve the above problems, a pressurization type freeze concentration apparatus of the present invention has a tapered hole in which a lower part is narrowed in a lower part of a cooling cylinder having a mother liquor container in an upper part. A pressurizing cylinder is connected through a heat insulating cylinder, a discharge pipe for collecting concentrated liquid is connected to the upper part of the tapered hole, and an endless tensile wire for pulling ice crystals is provided in the mother liquor container, the cylinder, and the heat insulating cylinder. A device which is fed through the pressurizing cylinder from above to below, wherein the cooling cylinder has two stages, the first cooling cylinder has an elongated tubular body, and the second cooling cylinder and the mother liquor container are connected to each other. A proper number of pipes that are directly connected to each other are provided with a pre-cooling device, and the inner diameter of the second cooling cylinder has a tapered hole larger than that of the first cooling cylinder.

[Operation] The ice crystals obtained by cooling and freezing the mother liquor in the first cooling cylinder are added to the outer periphery of the ice crystals by the second cooling cylinder to freeze the ice crystals. The size increases in the radial direction. Further, the ice crystals are pulled into the pressurizing cylinder by the tensile wire and are melted in the pressurizing cylinder. Further, the high-concentration solute solution in the ice crystals is squeezed from the lower side to the upper side by pressurization by the pressure cylinder, and melted and separated from the discharge pipe.

[Embodiment] An embodiment of the present invention will be described in detail below with reference to FIG.

FIG. 1 is a systematic diagram of this device. In FIG. 1, the inner diameter is uniform and vertical even below the mother liquor container 2 for temporarily storing the raw material liquid 3 which is an aqueous solution containing a solute. A first cooling cylinder 4 having an inner tube 4a that is a cylindrical body is connected. Furthermore, a second cooling cylinder 5 having an inner pipe 5c whose inner wall surface shape is slightly divergent and whose diameter is larger than that of the inner pipe 4a is connected to the lower portion of the first cooling cylinder 4.

Then, bypass pipes 2a and 2b connected to the container 2 are connected to the connecting portion 5b between the inner pipe 4a and the inner pipe 5c. This bypass pipe 2
A precooling jacket 18a is provided at a, and a precooling jacket 18b is provided at the bypass pipe 2b. Further, the precooling jacket 18a has an inlet 19a and an outlet 19b.
However, the jacket 18b also has an inlet 20a and an outlet 20b.
And each of these two jackets
The cooling medium 21 is sent to the respective inlets 19a, 20a by a pump (not shown), and is circulated in the jackets 18a, 18b, and then discharged from the outlets 19b, 20b. There is.

Further, the first cooling cylinder 4 is provided with a jacket 6a surrounding the inner pipe 4a, and the second cooling cylinder 5 is similarly provided with a jacket 6b surrounding the inner pipe 5c. These jackets 6a and 6b are routed
Connected by 6e.

The jackets 6a and 6b are provided with an inflow port 6c and an outflow port 6d, and a cooling medium 7 having a temperature of around −30 to −15 ° C. is sent through the inflow port 6c by a pump (not shown), After circulating through 6a and 6b, it is discharged from the outlet 6d.

The upper flange 9a of the pressurizing cylinder 9 is connected to the lower flange 5a of the second cooling cylinder 5 with the heat insulating cylinder 8 interposed therebetween. The inner tube 9a of the pressurizing cylinder 9 has a tapered hole with a narrowed lower portion, is provided with an inlet 10a and an outlet 10b, and a jacket 10 surrounding the inner tube 9a is provided in the pressurizing cylinder 9. is there.

In this jacket 10, 2 to 2 by a pump (not shown)
The cooling medium 11 having a temperature of 5 ° C. is fed from the inlet 10a and circulated, and then discharged from the outlet 10b.

A recess pocket 12 for storing liquid is provided in the upper portion of the inner wall of the inner pipe 9a near the heat insulating cylinder 8, and a drain pipe 13 is connected to the pocket 12.

Further, a pump 1 for injecting the raw material liquid 3 above the container 2
Is installed, and the chain 17, which is an endless traction body that is downwardly fed back by a motor (not shown) on the central axis of the device, is the container 2, the inner pipe 4a, the inner pipe 5c, the heat insulating cylinder 8 and the pressurization. It is provided so as to penetrate the tube 9.

Next, the processing functions of each part of the present apparatus will be described in detail below.

The raw material liquid 3 is poured into the container 2 by the pump 1, and the raw material liquid 3
Flows from the container 2 into the inner pipe 4a of the first cooling cylinder 4 and the connecting portions 5b of the second cooling cylinder 5 through the bypass pipes 2a and 2b.

Here, the raw material liquid 3 passing through the bypass pipes is appropriately cooled by the cooling medium 21 circulating in the precooling jackets 18a and 18b of the bypass pipes 2a and 2b.

Further, the raw material liquid 3 is cooled in the inner pipe 4a by the cooling medium 7 circulating in the jacket 6a of the first cooling cylinder 4, and frozen to become ice crystals 16a.

Since this ice crystal 16a is frozen around the chain 17,
As the chain 17 descends, it is pulled by the second cooling cylinder 5. The pulled ice crystals 16a are poured by the bypass pipes 2a and 2b at the connection portion 5b of the second cooling cylinder 5. After the precooled raw material liquid 3 is added, it is further cooled by the cooling medium 7 in the jacket 6b and further frozen to form the second ice crystals 16b.

Here, since the inner pipe 5c of the second cooling cylinder 5 has a divergent structure, the ice crystal 16b can suppress the rise in ice crystal internal pressure due to the freezing.

The ice crystals 16b having an appropriate freezing hardness are further pulled by the chains 17 and pressed into the pressurizing cylinder 9.

By the cooling medium 11 circulating in the jacket 10 of the pressurizing cylinder 9, the ice crystals 16b passing through the inner pipe 9a are heated and appropriately melted.

Further, the ice crystal 16b pulled by the chain 17 from the upper side by the taper hole of the pressurizing cylinder 9 and press-fitted has a higher ice crystal inner pressure in the lower portion and a lower ice crystal inner pressure in the upper portion.

By the way, the freezing point of the ice crystals 16b decreases as the pressure increases or the solute concentration increases, so that as the ice crystals 16b passing through the pressurizing cylinder 9 move downward, the solution having a high solute concentration becomes While melting and separating sequentially from 16b,
It is squeezed out to the upper side where the pressure is low and flows into the pocket 12.

The concentrated liquid 14 that has flowed into the pocket 12 flows out to a tank (not shown) through the discharge pipe 13 and is stored therein.

In addition, residual ice crystals 16b having a low solute concentration that have passed through the pressurizing cylinder 9
Will fall into tank 15.

In the above example, the raw material liquid 3 was precooled by the two bypass pipes 2a and 2b and supplied to the connecting portion 5b, but a large number of bypass pipes provided with these precooling jackets may be provided. Also, instead of these pre-cooling jackets,
The jacket 6a of the first cooling cylinder 4 directly cools the raw material 3 in the bypass pipe, and at the same time, a heater is provided at a position where it can be directly heated without coming close to the jacket 6a. May have a heated structure so as not to freeze.

In this way, the cooling cylinder has a two-stage structure, and the first
The ice crystals 16a, which are first purified in the cooling cylinder 4, are made to be slender, so that the raw material liquid 3 is quickly frozen, and the second cooling cylinder 5 precools the raw material liquid, which easily forms ice. Since the ice crystals 16a were aged to form ice crystals 16b while adding 3, ice columns in the ice crystals 16b having a uniform freezing hardness can be purified.

[Effects of the Invention] As described above, according to the present invention, in a two-stage cooling cylinder, ice crystals frozen in the first cooling cylinder are pre-cooled in the second cooling cylinder. The above raw material liquid was added and frozen to increase the ripening of the ice crystals and increase the diameter of the ice crystals. This makes it possible to increase the amount of ice crystals that are pressed into the pressurizing cylinder and to semi-melt them so as to uniformly reduce the crystal hardness thereof, thus enhancing the processing function of concentrated liquid separation.

[Brief description of drawings]

FIG. 1 is a system sectional view showing an embodiment of the present invention, and FIG. 2 is a view showing a conventional example. In the figure 1 ... Pump 2 ... Container 2a, 2b ... Bypass pipe 3 ... Raw material liquid 4 ... 1st cooling cylinder 4a ... Inner pipe 5 ... 2nd cooling cylinder 5a, 9a ... Flange 5b・ ・ Connecting part 5c ・ ・ Inner tube 6a, 6b ・ ・ Jacket 6c, 10a, 19a, 20a ・ ・ Inlet 6d, 10b, 19b, 20b ・ ・ Outlet 6e ・ ・ Route 7,11,21 ・ ・ For cooling Medium 8 ... Insulation cylinder 9 ... Pressurization cylinder 9a ... Inner tube 10 ... Jacket 12 ... Recessed pocket 13 ... Discharge pipe 14 ... Concentrated liquid 15 ... Tanks 16a, 16b ... Ice crystals 17 ...・ Chains 18a, 18b ・ ・ Jacket

Claims (1)

[Claims] 1. A cooling cylinder having a mother liquor container in the upper part thereof is connected to a lower part of a pressurizing cylinder having a tapered hole constricted in the lower part through an adiabatic cylinder, and the concentrated liquid is collected in the upper part of the tapered hole. An endless tensile wire for pulling ice crystals is connected to the discharge pipe, and the mother liquor container, the cylinder, the heat insulating cylinder,
A device that is fed from the upper side to the lower side in a pressurizing cylinder, wherein the cooling cylinder has two stages, the first cooling cylinder has an elongated cylindrical body, and the second cooling cylinder and the mother liquor container are directly connected to each other. A pressurization type freeze concentrator, wherein a suitable number of pipes to be connected are provided with a precooling device, and the second cooling cylinder has an inner diameter larger than that of the first cooling cylinder.