JPH0556162B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a pressurized freeze-concentrator for producing various types of drinking water, medical solutions, or other concentrated liquids.

[Prior Art] The so-called pressurized freeze concentration method involves once freezing a solution and applying pressure to the frozen solid ice crystals to separate a solute-rich solution from the ice crystals to produce a concentrated solution. The freezing point (freezing point) of a solution depends on the concentration of the solution, but it also changes depending on the pressure applied to the solution, that is, the freezing point decreases as the concentration and pressure increase, and This technology was developed focusing on the fact that the solute in the solid section (ice crystal) moves from the high pressure side to the low pressure side inside the ice crystal.

However, after separating and extracting the concentrated liquid, dilute ice crystals of the solute remain, so these are discharged from the device as residual ice crystals, and a tensile wire bonded to the ice crystals is used to pressurize the ice crystals. Methods such as removing the remaining ice crystals using mechanical force or installing a separate heater to melt the remaining ice crystals have been used, but this makes the structure of the device itself complicated. Put it away.

Moreover, the mechanical energy required to remove the remaining ice crystals and the thermal energy required to melt the remaining ice crystals are consumed, which increases the manufacturing cost of the concentrated liquid.

[Objective] The present invention is capable of providing a pressurized freezing and concentrating device with a residual ice crystal removing mechanism that is equipped with a residual ice crystal removing mechanism that has a simple structure and that reduces the energy consumption required for residual ice crystal removal.

[Means] In order to achieve the above object, the pressurized freeze concentrator with residual ice crystal removal mechanism according to the present invention has a mother liquid container in the upper part and a lower part of a vertical cooling cylinder having a cooling section for freezing. Connect the upper part of the pressurizing cylinder, which has a tapered hole and a cooling part, to the top of the pressurizing cylinder, and connect the drain pipe for discharging the separated concentrated liquid to the outside to the taper hole of the pressurizing cylinder, and then connect the bottom of the pressurizing cylinder to the taper hole of the pressurizing cylinder. is equipped with a lower tank, and endless tensile wire rods are
It enters the lower tank through a hole drilled in the bottom of the mother liquor container, passes through the inside of the cooling cylinder and the pressurizing cylinder, is reversed and raised by a wheel, and is returned from the mother liquor container to the cooling cylinder by a guide wheel. The hot water or hot air heat-exchanged in the condenser of the cooling unit that supplies low-temperature cooling medium to the cooling part of the cooling cylinder or the cooling part of the pressurizing cylinder is It is assumed that the wire is guided to the tensile wire rod located appropriately below.

[Operation] Hot water or hot air that has enough heat to melt residual ice crystals by exchanging heat with the high-temperature cooling medium in the condenser of the cooling unit that supplies low-temperature cooling medium to the cooling section of the equipment. is guided to the remaining ice crystals which are discharged from the tapered hole of the pressure cylinder into the lower tank while being bonded to the tensile wire.

The remaining ice crystals obtain heat of fusion by exchanging heat with hot water or hot air and melt, and the remaining ice crystals separate from the tensile wire before the tensile wire reaches the wheel in the lower tank.

[Embodiments] First and second embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a first embodiment of the apparatus according to the present invention, in which a pressurizing part is installed at the bottom of a vertical cooling cylinder 2, which has a mother liquor container 1 at the top, into which mother liquor for concentration is supplied from a mother liquor supply pump P1. A pressurizing cylinder 3 whose inner surface is tapered downward is connected.

A drain pipe 6 is connected to the tapered hole 4 of the pressurizing cylinder for collecting the concentrated liquid separated from the ice crystals into a liquid recovery container 5 outside the pressurizing cylinder.

Further, a lower tank 7 having a drain valve V at the bottom is provided below the pressurizing cylinder 3, and a tensile wire 8 such as a chain, which is endlessly fed, is passed through a hole in the bottom of the mother liquor container 1 for cooling. It passes through the cylinder 2 and pressurizing cylinder 3 and enters the lower tank 7, is reversed upward by the wheel 9 inside, is driven by the drave wheel 10,
The liquid is sent from the supply wheel 13 via the intermediate guide wheels 11 and 12 to the mother liquor container 1 and the cooling cylinder 2 as described above.

The cooling cylinder 2 is provided with a jacket 14 serving as a cooling section, and 15a and 15b each indicate an inlet and an outlet for a cooling medium.

A jacket 16 is also provided on the pressurizing cylinder 3, which is a pressurizing body, and a low-temperature cooling fluid is supplied to this jacket 16 depending on the method of forming ice crystals, and ice crystals are supplied to the jacket 16 during pressurization. It is possible to flow a fluid to melt the surface appropriately,
Reference numerals 17a and 17b indicate respective inlets and outlets for fluid.

The cooling unit 18a that cools the cooling medium supplied to the cooling cylinder jacket 14 includes:
The refrigerant heat exchanged in the cooler 19 is transferred to the compressor 2.
0, the air is compressed and discharged, and is supplied to the cooler 19 again via the condenser 21.

Further, the condenser 21 of the cooling unit 18 is, for example, a water-cooled type, and cooling water is supplied to the condenser 21 by a cooling water supply pump P2.
This cooling water is supplied to the cooling water supply pump P2 and the condenser 21.
For example, while passing through a cooling tower 22 disposed at an appropriate location between the two, the cooling tower 22 is cooled to an appropriate temperature and reaches the condenser 21.

For example, a three-way valve 23 is provided on the cooling water outflow side of the condenser 21 to bypass the cooling water, and one cooling water return pipe 24a returns directly to the cooling water supply pump P2.
and the other are connected to the hot water supply pipe 24b, respectively.

Further, the other end of the hot water supply pipe 24b is guided into the lower tank 7, and a nozzle 25 provided at the tip end of the hot water supply pipe 24b is connected to the pressure cylinder 3.
It is placed at a suitable location where hot water can be supplied to the tensile wire rod 8' located appropriately below.

In the apparatus configured as described above, the concentrated mother liquor supplied from the mother liquor container 1 into the cooling cylinder 2 is frozen into ice crystals by the cooling medium flowing through the jacket 14 of the cooling cylinder, and is formed into the tensile wire rod 8. Join.

The tensile wire 8 is driven to descend within the cooling cylinder 2, thereby causing the ice crystals to also descend.

The ice crystals that have passed through the cylinder together with the tensile wire enter the next pressurizing tube 3, where they are squeezed and pressurized by the inner surface of the tapered hole of the pressurizing tube.

This pressurization lowers the freezing point of the ice crystal, melts a large part of the solute concentration in the ice crystal, and the melted concentrate follows the pressure gradient inside the ice crystal to the upper entrance of the tapered hole in the direction of low pressure. The liquid moves to the side and is collected into the liquid recovery container 5 through the drain pipe 6 connected to the inlet of the tapered hole 4.

The solute-rich solution in the ice crystals is separated and extracted, and the ice crystals are diluted in solute content and are discharged from the taper hole 4 into the lower tank 7 while remaining bound to the tensile wire 8 as residual ice crystals 26. Ru.

By appropriately changing the outflow direction of the three-way valve 23, the hot water heat-exchanged in the condenser 21 is supplied from the nozzle 25 to the tensile wire 8'.
The remaining ice crystals 26 bonded to the tensile wire 8' are dissolved and removed by hot water, and accumulated in the lower tank 7 as remaining ice crystal melting water 26a.

In this embodiment, the remaining ice crystal melting water 26a is circulated and used as cooling water, but the remaining ice crystal melting water 26a may contain solutes that corrode the cooling pipe in the condenser 21, If solutes that adhere to the inner surface of the tube and reduce the heat exchange rate are included, a separate cooling water tank or the like may be provided.

FIG. 2 shows a second embodiment, in which, for example, an apparatus constructed substantially in the same manner as the first embodiment is provided with a cooling unit 18b for supplying a low-temperature gaseous cooling medium to the jacket 14 in the cooling cylinder. At the same time, the fan 27 in this cooling unit 18b
The hot air inlet 28a of the hot air duct 28 is arranged on the hot air blowing side of the air-cooled condenser 27 according to a, so that the hot air that has been heat exchanged in the condenser 27 is guided into the hot air duct 28. There is.

Further, the hot air outlet 28b of the hot air duct 28 is arranged at a suitable position in the lower tank 7 so that the hot air can be guided to the tensile wire 8' located appropriately below the pressurizing cylinder 3.

Note that a hot air inlet 28a of the hot air duct 28 is provided with a blower for introducing hot air, so that the amount of hot air introduced into the hot air duct can be adjusted as appropriate.

In the second embodiment configured as described above, the concentrated liquid in the ice crystals is selectively separated in the pressurizing cylinder 3 and concentrated from the drain pipe 6 to the liquid recovery container 5, as in the first embodiment. Liquid is stored.

The remaining ice crystals 26 whose solute content has been diluted are the tensile wire 8
The remaining ice crystals 2 are discharged into the lower tank 7 in a state where they are combined with the ice crystals, but the remaining ice crystals 2 are exchanged with the high temperature cooling medium in the condenser 27.
Since hot air with enough thermal energy to melt the remaining ice crystals 2 is supplied from the hot air duct 28, the remaining ice crystals 2
6 easily melts and separates from the tensile wire 8' before reaching the wheel 9 in the lower tank 7.

[Effect] As explained above, according to the pressurized freeze concentrator with residual ice crystal removal mechanism according to the present invention, heat exchange is performed within the cooling unit for supplying the cooling medium used for freezing the mother liquor for concentration. The remaining ice crystals, which are discharged from the taper hole to the lower tank while bonded to the tensile wire, are melted appropriately below the pressurizing cylinder by hot water or hot air, and the remaining ice crystals are released together with the tensile wire into the lower tank. This removes residual ice crystals from the tensile wire before they reach the wheels.

Therefore, a mechanism for removing residual ice crystals can be added without complicating the structure of the device itself, and by using the thermal energy obtained from the condenser in the cooling unit for the heat of melting of the residual ice crystals, it is possible to reduce the concentration of concentrated liquid. It is possible to provide a pressurized freeze concentrator that can reduce the energy consumption required for production and reduce the cost of producing a concentrated liquid.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the configuration of a first embodiment of the apparatus according to the present invention, and FIG. 2 is a schematic diagram of the configuration of the second embodiment. In the figure, 1... Mother liquid container, 2... Cooling cylinder,
3... Pressure tube, 4... Tapered hole, 5... Liquid recovery container, 6... Drain pipe, 7... Lower tank, 8...
... Tensile wire rod, 9 ... Wheel, 10 ... Drive wheel, 11, 12 ... Intermediate guide wheel,
13... Supply wheel, 14, 16... Jacket, 15a, 15b... Cooling medium inlet/outlet, 17
a, 17b...Fluid inlet/outlet, 18a, 18b...
...Cooling unit, 19...Cooler, 20...Compressor, 21...Condenser, 22...Cooling tower, 2
3...Three-way valve, 24a...Cooling water return pipe, 24b
... Hot water supply pipe, 25 ... Nozzle, 26 ... Remaining ice crystals, 26a ... Remaining ice crystal melting water, 27 ... Condenser,
28...Hot air duct, 28a...Hot air inlet, 2
8b... Warm air outlet, P1... Mother liquor supply pump,
P2...Cooling water supply pump, V...Valve.

Claims (1)

[Claims] 1 Connect the upper part of a pressurizing cylinder with a downwardly tapered hole and a cooling part to the lower part of a vertical cooling cylinder that has a mother liquor container on the top and a cooling part for freezing, and A drain pipe for discharging the separated concentrated liquid to the outside is connected to the taper hole, and a lower tank is provided below the pressurizing cylinder, so that an endless tensile wire can be connected to the drain pipe from the hole drilled at the bottom of the mother liquor container. It passes through the inside of the cooling cylinder and the pressurized cylinder and enters the lower tank, where it is reversed and raised by a wheel, and sent from the mother liquor container to the cooling cylinder again by a guide wheel, and the liquid in the cooling cylinder is The hot water or hot air heat-exchanged in the condenser in the cooling unit that supplies low-temperature cooling medium to the cooling section or the cooling section of the pressurizing tube is guided to the tensile wire rod located appropriately below the pressurizing tube. A pressurized freeze concentration device with a residual ice crystal removal mechanism.