JPH03242205A - Dewatering and drying device - Google Patents

Abstract

PURPOSE:To prevent environmental pollution by using pentafluoro-propanol (5FP) as a cleaning soln., placing a water-washed article in the vapor phase of an evaporation tank to dewater the article, cooling the 5FP with dissolved water in a cooling tank and phase-separating the 5FP by gravity. CONSTITUTION:The 5FP without CFC control is used as a cleaning soln. and evaporated in the housing 7 of an evaporation tank 2. A water-washed article 14 is placed in the vapor phase 3 in the housing 8 and dewatered, the vapor is cooled and condensed in a cooling pipeline 13, and the condensate is allowed to flow down and introduced into a cooling tank 5 from a receiving member 4. The 5FP with dissolved water is cooled by a cooling means 20, the water is phase-separated by gravity ant the upper layer and the 5FP at the lower layer, the water overflows from the surface layer and is discharged, and the 5FP without water ascends from a passage 24 at the bottom and is returned into the housing 7 of the evaporation tank 2 through a weir 24 and a pump 26. Environmental pollution is prevented in this way, and water is efficiently phase-separated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a draining and drying device for removing water adhering to the surface of an article that has been washed with water.

BACKGROUND OF THE INVENTION Various plated products, optical lenses, semiconductor materials, etc. need to be washed with water after various surface treatments and then dried quickly and safely. A typical prior art is, for example, Japanese Patent Publication No. 63-17484 by the present applicant. In this prior art, an azeotropic mixture of trichlorotrifluoroethane and ethanol is used as a washing liquid, and articles that have been previously washed with water are immersed in a dehydration tank, which is a boiling bath for the washing liquid, to remove water and separate the products. The washing liquid containing the separated free water is sent to a water separation tank, where water is floated to the surface due to the difference in specific gravity and phase separated, and the separated washing liquid is circulated to a dehydration tank.

Problems to be Solved by the Invention In such prior art, trichlorotrifluoroethane destroys the ozone layer and worsens the global environment, and its use has been suppressed, resulting in so-called fluorocarbon regulations.

An object of the present invention is to provide a draining and drying device that can completely remove water adhering to the surface of an article using a washing liquid that does not degrade the environment.

Means for Solving the Problems The present invention provides pentafluoropropanol (abbreviated as 5FP)
an evaporation tank in which the article to be cleaned is introduced into the vapor space; and a receiving member provided at the lower part of the space in the evaporation tank to receive pentafluoropropanol condensed on the surface of the article and in which water is dissolved. , a cooling tank for cooling pentafluoropropanol in which water has been dissolved from the receiving member and returning the pentafluoropropanol from which water has been separated to the evaporation tank.

The present invention heats and evaporates pentafluoro-10 panol which is interposed between a receiving member and a cooling tank and is hydrolyzed.
It is characterized by including a distillation tank that condenses the evaporated pentafluoropropanol and returns it to the evaporation tank and leads the liquid to a cooling tank.

Function According to the present invention, in the evaporation tank, an article is introduced into the 5FP vapor space, whereby the 5FP condenses on the article surface. There is water attached to the surface of the article that has been washed with water in advance, and this attached water is dissolved in 5FP, and 5FP penetrates between the article surface and the attached water. Therefore, the adhered water loses its adhesion to the surface of the article and falls under its own weight. The 5FP aqueous solution that fell under its own weight was
Received on a receiving member such as a saucer. If,
When the 5FP aqueous solution that falls under its own weight falls into the boiling RR of the evaporation tank, when the water concentration of the liquid phase is 5 to 129≦, the water concentration of the gas phase is constant at approximately 6%. A problem arises in that water in the liquid phase, the boiling liquid, accumulates. In the present invention, 5FP falling from the surface of the article
7) This problem does not occur because the receiving member receives the C solution and prevents it from falling into the liquid phase of the evaporation tank.

The 5FP aqueous solution received by the receiving member is guided to a cooling tank and cooled.

The liquid from the receiving member contains 5FP and water, so 5F
It is necessary to separate P and water. In the cooling tank, this 5F
The P aqueous solution is cooled, thereby reducing the solubility of water in 5FP, and due to the difference in solubility due to this temperature difference,
Separate the water. The separated water undergoes phase separation and floats to the surface due to the difference in specific gravity, and therefore 5FP rises from the top of the liquid in the cooling tank.
Water with almost no dissolved water can be discharged.

The 5FP from which water has been separated in the cooling tank is returned to the evaporation tank and boiled again to be reused.

Further, according to the present invention, a distillation tank is interposed between the receiving member and the cooling tank, and the 5FP aqueous solution from the receiving member is heated and evaporated,
The evaporated 5FP is condensed and returned to the evaporation tank. The condensed 5FP thus obtained is the 5FP from the receiving member.
When the water concentration in the aqueous solution is 5 to 12%, the water concentration of 5FP evaporated and condensed in the evaporation tank is about 68≦ and is almost constant. The liquid in the evaporation tank is returned to the evaporation tank to be reused, and when the water concentration is between 6% and 12%, its evaporation increases its water concentration, thus cooling the 5FP aqueous solution that has been raised by 4 degrees. By introducing the water into a tank, the solubility decreases due to the temperature difference, thereby effectively dehydrating the water.

In this way, dehydration in the vapor space in the evaporator is
Since the surface tension of 5FP is smaller than that of water, 5FP invades the boundary between the water adhering to the surface of the product and the surface of the product, and the adhering water weakens the adhesion force, and this adhesion force is equal to the dissolving power of 5FP. The larger the value, the smaller the value can be made. In the present invention, 5FP is boiled in an evaporation tank to, for example, about 80°C.
By setting the above, the solubility of water in 5FP is about 16%, and when the water concentration in SFP in the liquid of the steam tank is 5 to 12%, the water concentration in the steam space is about 6%.
Therefore, in this vapor space, the solubility of water in 5FP will be maintained in an unsaturated state. In this way, water adhering to the surface of the article can be effectively removed in the steam space.

Embodiment FIG. 1 is an overall system diagram of an embodiment of the present invention. This draining/drying device uses a liquid 1 that is 5FP as a washing liquid, and includes a heating evaporation tank 2 that heats and evaporates the 5FP, and water that falls from an article to be cleaned disposed in the space 3 of this evaporation tank 2 and dissolves the water. It has a receiving member 4 that receives the 5FP, and a cooling tank 5 that cools the 5FP in which the water received in the receiving member is dissolved. It is returned to the evaporation tank 2 via the pipe 6 and circulated. Bouncing 7 in evaporation tank 2
．． 8, and one bouncing 7 is a liquid 5FP
is stored as indicated by reference numeral 1, and 5FP of this liquid is heated by heating means 9. Therefore, the gas in the space 10 above the bouncing 7 is removed from the partition wall 11.
．． It is connected to the bouncing 8 through the space between 12 and guided to the space 3. A cooling heat transfer tube 13 to which a cooling medium such as cooling water is supplied is provided above the space 3 to cool and condense the gas in the space 3 . This condensed liquid is collected on the receiving member 4 forming the bottom of the bouncing 8.

In space 3, there is an article with reference numeral 14 that has been previously washed with water.
Charge as shown. 5FP condenses on one surface of the article 14, water adhering to the surface of the article 14 is dissolved in the 5FP, and the adhering water loses its adhesive force and falls onto the receiving member 4. The liquid that is the 5FP aqueous solution from the receiving member 4 and the liquid that overflowed from the weir 15 in the bouncing 7 are guided to the inlet between the cooling tank 5 and the partition member 28 via the pipes 16 and 18 and the pipe 19. .

The cooling tank 5 is provided with a cooling heat exchanger tube 20 to which a cooling medium such as cooling water is supplied, and the liquid is cooled, whereby the solubility of 5FP in water is reduced and the water liberated from the SFP has a specific gravity. It floats up due to the difference and is discharged from the weir 21 through the pipe 22. Passage 24 at the bottom of the partition wall 23
The 5FP from the weir 25 is returned to the liquid in the bouncing tank 7 of the evaporation tank 2 via the pump 26 and the pipe line 6.

FIG. 2 is a graph showing the solubility of water in SFP. The solubility of water is about 10% by weight at 0°C, 13% by weight at 30°C and about 16% by weight at 80°C.

Figure 3 is a graph showing the solubility of 5FP in water,
Approximately 3% by weight at O″C, approximately 6% by weight at 30°C
, about 9% by weight at 80°C.

FIG. 4 shows a vapor-liquid equilibrium curve for a mixture of 5FP and water. The azeotropic composition of the mixture of 5FP and water is 94% by weight of 5FP and 6% by weight of water, and when the water concentration of liquid 1, which is a mixture of 5FP and water, is in the range of 5 to 12% by weight, evaporation occurs. The water concentration in the gas phase in the space 3.10 of tank 2 is about 6% by weight and is approximately constant. Therefore, the water concentration of liquid 1 is 5 to 12 weight? 6, the water concentration in the gas phase in space 3.10 is approximately 6%, as mentioned above, so that in this space 3 the concentration of water in the gas phase of article 14 is approximately 6%, as mentioned in connection with FIG. 2 above. The solubility of water adhering to the surface in 5FP is, for example, 10% or more at a temperature of 0° C. or higher, as described above, and therefore 5FP is in an unsaturated state with water.

Therefore, the water adhering to the surface of the article 14 can be sufficiently dissolved in the 5FP.

The 5FP aqueous solution received in the receiving member 4 is cooled in the cooling tank 5. By cooling this liquid, the solubility of 5FP in water is reduced, for example, at 0° C., the solubility of 5FP is 3%, as described in connection with FIG.
Separation from FP can be performed, and free water rises to the surface and flows to weir 2.
1 and is discharged from conduit 22.

In the liquid 1 in the bouncing 7 of the evaporation layer 2, when the water concentration is, for example, about 6 to 12% by weight, there is a risk that the water concentration will increase. The floating 5FP of the liquid 1, which has a high water concentration, is guided from the weir 15 to the cooling tank 5 via the pipe 18, and in this way, in the cooling tank 5, dehydration is effectively performed by reducing the solubility due to the temperature difference. I can do it.

When the liquid from the pipe 19 is cooled in the water separation layer 5, water is generated in the form of a mist, and the water is not separated and floated smoothly due to the difference in specific gravity, but the water is in the form of a mist and flows into the pipe 5 along with the 5FP. Water repellent material, to prevent being led to
For example, a filter 29 made of polytetrafluoroethylene (PTFE) prevents the mist water from being entrained into the pipe line 6 side.

FIG. 5 is an overall system diagram of another embodiment of the present invention.

This embodiment is similar to the embodiments of FIGS. 1-4 described above;
Corresponding parts are given the same reference numerals. It should be noted that in this embodiment, there is a distillation tank 3 between the receiving member 2 and the cooling tank 5.
0 is interposed. The liquid from the receiving member 2 is led through the line 16 into the liquid indicated by reference numeral 31 in the evaporator tank 30 .

A heating means 32 is provided in this liquid 31, and this liquid 31 is heated and evaporated, and the vapor in the air 1 m 33 is cooled and condensed by a cooling heat transfer tube 34 to which a cooling medium is supplied. The upper part of the space 33 is connected to the upper part of the bouncing 8 of the evaporation tank 2 via a pipe 34. Distillation tank 30
Now, when the water concentration of the liquid 31 is in the range of about 5 to 12% as described in connection with FIG. 4 above, the water concentration of the gas phase in the space 33 is about 69≦, The gas phase condensate is returned to the evaporation tank 2 from the pipe line 36 by the pump 37 and circulated therein. In this way, the liquid 31 in the distillation tank 30
The water concentration of the liquid 31 is increased, and the liquid 31 with high water concentration is passed through the weir 38
overflows and is led to the cooling tank 5 from the pipe 39 by the pump 40. 5FP with reduced water concentration in cooling tank 5
The aqueous solution is returned to the evaporation tank 2 from the pipe 6 by the pump 37 as described above. By increasing the water concentration of the liquid 31 in the distillation tank 30, in the cooling tank 5, the effect of reducing the solubility of 5FP in water due to the temperature difference is reduced.
done effectively.

In the above-described embodiment, the receiving member 4 constitutes the bottom of the housing 8 of the evaporator tank 2, but the receiving member may be provided in the space 3 separately from the bottom of the housing 8. According to the present invention, by using 5FP, draining and drying can be performed without causing environmental deterioration. Furthermore, according to the present invention, by placing the article in the 5FP steam space in the steam tank, water adhering to the surface of the article is drained, and the 5FP condensed on the article surface is transferred to the receiving member in this steam space. Therefore, the 5FP in which the water from this receiving member is dissolved is cooled in a cooling tank, and due to the decrease in water solubility due to the temperature difference,
Water is separated, and the separated water floats to the surface due to the difference in specific gravity, thus allowing phase separation of the water.

Furthermore, according to the present invention, a distillation tank is interposed between the receiving member and the cooling tank, and by increasing the concentration of liquid water in the distillation tank and concentrating the water, separation of cooling water in the cooling tank is effectively achieved. You will be able to do this in a specific manner.

[Brief explanation of drawings]

FIG. 1 is an overall system diagram of one embodiment of the present invention, and the second (2I)
is a graph showing the solubility of water in SFP, Fig. 3 is a graph showing the solubility of 5FP in water, Fig. 4 is a graph showing the vapor-liquid equilibrium curve of a mixture of 5FP and water, and Fig. 5 is a graph showing the solubility of 5FP in water. FIG. 3 is an overall system diagram of another embodiment of the invention. DESCRIPTION OF SYMBOLS 1...liquid, 2...evaporation tank, 3, 10...space, 4 receiving member, 5...cooling tank, 9.32 heating means, 20...
・Cooling means

Claims (2)

[Claims] (1) An evaporation tank that heats and evaporates pentafluoropropanol and introduces the article to be cleaned into the vapor space; and an evaporation tank that heats and evaporates pentafluoropropanol and introduces the article to be cleaned into the vapor space; Drainage drying characterized by comprising a receiving member for receiving propanol, and a cooling tank for cooling the pentafluoropropanol in which water has been dissolved from the receiving member and thereby returning the water-separated pentafluoropropanol to the evaporation tank. Device. (2) Interposed between the receiving member and the cooling tank, the pentafluoropropanol in which water is dissolved is heated and evaporated, the evaporated pentafluoropropanol is condensed and returned to the evaporation tank, and the liquid is transferred to the cooling tank. 2. The draining and drying device according to claim 1, further comprising a distillation tank for introducing water into the water.