JPH04338949A - Evaporation/concentration device for aqueous solution - Google Patents

Abstract

PURPOSE:To allow the execution of the evaporation/concentration operation of an aq. soln. while maintaining a specified evaporation rate even with any aq. soln. and even in any environment without applying a large load on the compressor of a heat pump circuit. CONSTITUTION:An air cooling means 12 which forcibly cools a refrigerant with air by a fan 13 is provided at the proper point in the heating area of the heat pump circuit 5. A liquid temp. detector 23 for detecting the concentrated liquid temp. in an evaporator 1 and a control means 24 which controls the fan 13 according to the detected temp. of this liquid temp. detector 23 are provided to allow the execution of control in such a manner that the refrigerant temp. is raised by stopping the fan 13 (or weakening the air quantity of the fan) when the temp. of the concentrated liquid falls below a reference value and the refrigerant temp. is lowered by driving the fan 13 (or increasing the air quantity of the fan) when the temp. of the concentrated liquid increases.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for evaporating and concentrating aqueous solutions, such as photographic processing waste liquids of silver halide photographic materials.

0002

[Prior Art] In general, photographic processing of silver halide photographic materials includes development, fixing, and water washing in the case of black and white materials, and color development, bleach-fixing (or bleaching and fixing) in the case of color photographic materials. , one or two functions such as water washing, stabilization, etc.
A combination of processes using three or more processing liquids is carried out. In photographic processing in which a large amount of light-sensitive material is processed, the components consumed during processing are replenished, and on the other hand, components that are eluted into the processing solution or concentrated by evaporation during processing (for example, bromide ions in the developer solution, A method is used to maintain the performance of the processing solution at a constant level by removing components of the processing solution (such as silver complex salts in the fixer) and keeping the processing solution components constant. A portion of the processing solution is discarded to remove thickening components during photographic processing.

[0003] In recent years, systems have been changing to systems in which the amount of replenishment fluid, including washing water, which is used as a replenishment fluid for washing, has been drastically reduced due to pollution and economic reasons. The waste liquid is led from the processing tank through a waste pipe, diluted with waste liquid from washing water, cooling water from automatic processors, etc., and then disposed of in the sewer, etc. However, photographic processing liquids other than these [e.g. Due to tightening of pollution regulations in recent years, it has become virtually impossible to dispose of bleach-fix solutions, bleach-fix solutions (or bleach-fix solutions), stabilizers, etc.] due to stricter pollution regulations in recent years. For this reason, each photo processing company pays a collection fee to a specialized waste liquid processing company to collect the waste liquid, or installs pollution treatment equipment. In order to entrust this waste liquid treatment to a waste liquid processing company, the waste liquid must be stored, which requires a considerable amount of space and is also extremely expensive. However, pollution treatment equipment has drawbacks such as extremely large initial investment (initial cost) and the need for a fairly large area for maintenance.

Specifically, as pollution treatment methods for reducing the pollution load of photographic processing waste liquid, there are two methods: (1) activated sludge method (for example, Japanese Patent Publication No. 51-12943, No. 51-7952, etc.), (4) Evaporation method (for example, Japanese Patent Publication No. No. 49-89437, No. 56-33
996, etc.), ■Electrolytic oxidation method (for example, JP-A-48-84
No. 462, No. 49-119457, No. 49-1194
58, Japanese Patent Publication No. 53-43478, etc.), ■ Ion exchange method (for example, Japanese Patent Publication No. 51-37704, Japanese Patent Publication No. 53-432)
71, JP-A-53-383, etc.), ■ reverse osmosis method (e.g., JP-A-50-22463, etc.), ■ chemical treatment method (e.g., JP-A-49-64257, JP-A-53-12152, etc.). Japanese Patent Publication No. 49-58833, Japanese Patent Publication No. 53-63763, Japanese Patent Publication No. 57-37395, Japanese Patent Publication No. 57-37396, etc.) are known, but these are still insufficient.

On the other hand, due to constraints in terms of water resources, rising costs for water supply and drainage, the simplicity of automatic processor equipment, and the work environment around automatic processors, in recent years stabilization treatment has been used instead of washing with water. Automatic developing machine that does not require piping for water supply and drainage outside the developing machine (so-called waterless automatic developing machine)
photo processing is becoming popular. It is desirable for this treatment to omit cooling water for controlling the temperature of the treatment liquid.

[0006] Since this kind of photographic processing that does not substantially use rinsing water or cooling water produces a small amount of waste liquid, it is possible to omit piping outside the machine for supplying and discharging liquid, which is considered to be a drawback of conventional automatic processors. This eliminates disadvantages such as difficulty in moving after installation, limited foot space, high cost for piping work during installation, and high energy costs for hot water supply pressure. The extremely large advantage of achieving compactness and simplification to the point where it can be used as a machine is exhibited.

On the other hand, since the waste liquid is not diluted with water, it has an extremely high pollution load, and it has become impossible to dispose of it not only in rivers but also in sewers in view of pollution regulations. Furthermore, the amount of waste liquid from this type of photographic processing (processing that uses a large amount of running water and does not involve washing with water) is
Although it's not much, even a relatively small-scale color processing lab store has about 10 liters a day.

[0008] The waste liquid generated from color processing lab shops is generally collected by a waste liquid recovery company and rendered harmless through secondary and tertiary treatment. Due to poor collection efficiency, it is difficult to get people to come and collect the liquid, causing problems such as waste liquid filling the store. In order to solve this problem, research has been conducted on heating the waste liquid to evaporate the water to dryness or solidify it so that it can be easily processed even in small-scale color processing lab shops.
For example, Utility Model Application No. 60-70841, etc.). Furthermore, some of these devices use the heat radiating section and the heat absorbing section of a heat pump circuit as heating means for an evaporating pot that evaporates and concentrates an aqueous solution, and as cooling means for a cooling pot that cools, condenses, and liquefies vapor.

[0009]

[Problem to be Solved by the Invention] However, since the concentration and properties of non-evaporable components in aqueous solutions such as photographic processing waste are not constant, the heat of the refrigerant passing through the heat radiating section increases due to the progress of concentration or the influence of outside temperature. If the temperature is too high, the operating conditions of the heat pump circuit may deteriorate. As a result, the evaporation rate decreases, and the temperature of the refrigerant passing through the heat radiation section increases abnormally, placing a large load on the compressor and shortening its lifespan.

[0010] This invention is intended to solve the above problem, and it is possible to maintain a constant evaporation rate for any aqueous solution and under any environment without placing a large load on the heat pump circuit, especially the compressor. The object of the present invention is to provide an apparatus for evaporating and concentrating an aqueous solution that can be operated as follows.

[0011]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a heat dissipation section of a heat pump circuit as a heating means for an evaporation pot that evaporates and concentrates an aqueous solution, and a cooling means for a cooling pot that cools, condenses, and liquefies vapor. In an evaporative concentrator equipped with a depressurizing means for communicating the evaporating pot and the cooling pot to reduce the pressure of the entire body using a heat absorbing section, an air cooling means for forced air cooling of the refrigerant by a fan is provided at an appropriate place in the heating area of the heat pump circuit. , a liquid temperature detector for detecting the temperature of the concentrated liquid in the evaporating pot, and a control means for controlling the fan according to the temperature detected by the liquid temperature device, the temperature of the concentrated liquid being a reference value. If the temperature drops further, stop the fan (or reduce the fan's airflow) to raise the refrigerant temperature, and if the temperature of the concentrate rises, drive the fan (or increase the fan's airflow) to raise the refrigerant temperature. It is configured so that it can be controlled to lower the temperature. In this case, the air cooling means may be installed anywhere as long as it is in the heating area of the heat pump circuit.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained based on embodiments shown in the accompanying drawings. In the figure, reference numeral 1 denotes an evaporation pot that can withstand reduced pressure, into which an aqueous solution (specifically, photographic processing waste liquid) is injected and stored. 2 is a cooling pot provided concentrically outside the evaporating pot 1, and the upper part of the cooling pot 2 communicates with the evaporating pot 1;
It is connected to a pressure reducing means 3 (which may use an ejector, a vacuum pump, or others) to reduce the pressure. It is known that when the inside of the evaporating pot 2 is brought under a reduced pressure lower than atmospheric pressure, boiling occurs below the boiling point of the material, and in this example, evaporation is carried out under this reduced pressure at a low temperature where gas generation is difficult to occur. It is.

Reference numeral 4 denotes a heating means three-dimensionally arranged in the evaporating pot. The heating means 4 uses the heat dissipation part of the heat pump circuit 5, and its surface temperature is 100° C. or less under reduced pressure evaporation, especially when odor gas is generated. In order to prevent this, it is most preferable to control the temperature at 20 to 60°C. The lower part of the heating means 4 is immersed in the photographic processing waste liquid W, and the upper part protrudes above the liquid level and is exposed to the air. The reason why the heating means 4 is three-dimensionally arranged so as to straddle the liquid and the air is to enable efficient heating of the liquid and the liquid surface at the same time.

Reference numeral 6 denotes a storage tank (container) containing photographic processing waste liquid W from a color processing laboratory shop, and 7 is a pumping means (electromagnetic valve) for pumping up the waste liquid from the storage tank 6 and feeding it into the evaporator 1. The pumping means 7 is activated when the liquid level in the evaporator 1 drops by a certain amount due to heating and evaporation. The waste liquid pumped up by this pumping means 7 is supplied to the heating means in the air in the evaporating pot 1 so as to be directly sprayed, or as shown in the figure, it is supplied through a suitable baffle plate 8 so as not to ripple the water surface. . Note that the submerged part of the heating means 4 and the part in the air are usually controlled at the same temperature, but in that case, the surface temperature of the part in the air is substantially higher due to the difference in heat transfer effect. Therefore, if the waste liquid is directly sprayed on this, unpleasant gas may be generated due to rapid heating. As a countermeasure, it is necessary to adjust the supply amount or to suppress the temperature of the heating means in the air below the gas generation temperature. Or
The heating means may be used separately for inside the liquid and outside the liquid to control the temperature separately.

Reference numeral 9 denotes a cooling means installed in the cooling pot 2. The cooling means 9 uses the heat absorption part of the heat pump circuit 5 to evaporate in the evaporation pot 1 and enter the cooling pot 2 through the upper space. The water vapor is captured and cooled and condensed. The condensed water is stored in the bottom 2a of the cooling pot 2 and collected in a recovery container 10 installed outside the pot. In this embodiment, this recovery is performed by a pressure reducing means 3 using an ejector 3a. That is, the water in the condensed water recovery container 10 is pumped up by the pump 3b, and the water is pumped up into the container 10 through the vertical pipe section of the ejector 3a.
When the liquid is returned to the inside, a vacuum area is created at the orthogonal part between the vertical pipe part and the horizontal pipe part, so the liquid accumulated in the bottom part 2a of the cooling pot 2 that communicates with the horizontal pipe part, the cooling pot 2, and the liquid connected thereto. The air inside the evaporating pot 1 is sucked, contributing to stabilizing the reduced pressure in both pots. Continuously performing condensation and recovery of condensed water here means that
When the pressure inside the evaporator 1 increases due to the generated steam, the pressure reduction balance is disrupted, but this is immediately cooled and condensed, effectively suppressing the pressure increase. Note that 10a is a storage container for water that overflowed the collection container 10,
The water stored in this container 10a can be directly poured into the sewer without any problem.

11 is a compressor for compressing the refrigerant of the heat pump circuit 5; 12 is an air cooling means for forced air cooling of the refrigerant by a fan 13; the air cooling means 12 can be installed anywhere in the heating area of the heat pump circuit 5; good. For example, as shown in FIG. 3, there is a refrigerant passage A between the compressor 11 and the heat radiating section that constitutes the heating means 4 of the evaporator 1, and a bypass-like refrigerant that is provided in parallel with the heat radiator that constitutes the heating means 4 of the evaporator. Either the passage B or the refrigerant passage C between the heat radiating section constituting the heating means 4 of the evaporator and the capillary tube 14 may be used, but the refrigerant passage A is most preferable. The capillary tube 14 serves as an expansion valve, and the heat absorbing portion on the downstream side of the capillary tube 14 is used as a cooling means 9a for water in the condensed water recovery container 10 and a cooling means 9 in the cooling pot 2. be done. That is, the upstream side of the capillary tube 14 is the heating area, and the downstream side is the cooling area. Thus, the refrigerant that has passed through the cooling means 9 of the cooling pot 2 flows back to the compressor 11.

Reference numeral 15 denotes a slurry reservoir section for storing components (slurry) that have been solidified to a high concentration by repeated evaporation and concentration, and the slurry reservoir section 15 is provided at the bottom of the evaporating pot 1. 1
Reference numeral 6 denotes a slurry outlet protruding from the outer surface of the side wall at the same level as the bottom surface of the slurry reservoir 15, and the outlet 16 is connected to the plug means 17.
It is sealed tightly. This stopper means 17 may be composed of a ball valve, a butterfly valve, or a slide valve, but in the case shown, it is composed of a packing material in order to maintain the reduced pressure state in the evaporator 1, and the handle 18 can be pulled or pushed. By doing so, the slurry outlet 16 can be opened and closed. 19 is a slurry collection container.

Reference numeral 20 denotes a rotating blade provided in the slurry reservoir 15, and the rotating blade 20 is fixed to the lower end of an output shaft 22 that hangs down from a drive source 21 installed on the top surface of the evaporating pot 1. The rotating blades 20 are configured to be able to completely stir the inner bottom surface of the slurry reservoir 15 and to easily sweep the slurry toward the outlet 16 thereof. Of course, it may be constructed so that it can be manually rotated by operating a handle.

A liquid temperature detector 23 detects the temperature of the concentrated liquid in the evaporating pot 1. The liquid temperature detector 23 detects the temperature in the liquid, the liquid surface temperature, or the vapor temperature in the upper space.
It is designed to be detected by a. The liquid temperature detector 23
Depending on the detected temperature, as shown in FIG. 2, outputs a drive/stop (on/off) signal or an air volume strength signal to the control means 24 for the fan 13 of the refrigerant air cooling means 12. Specifically, if the temperature of the liquid detected by the liquid temperature detector 23 is lower than the reference value determined by the temperature setting device, the refrigerant temperature is also low, so the fan 13 is stopped (or If the temperature of the liquid becomes higher than the standard value, the refrigerant temperature is also high, so drive the fan 13 (or increase the fan air volume). Controls to lower the refrigerant temperature,
Always keep the concentrated liquid in the evaporator 1 and the heating means 4 in the evaporator 1
This makes it possible to maintain the flowing refrigerant at a constant and appropriate temperature.

In the above embodiment, the pumping means 7 is operated to inject the waste liquid W into the evaporating pot 1 to a required level, and tap water is also injected into the condensed water recovery container 10 and stored therein. After that,
After the pump 3b of the pressure reducing means is operated, the compressor 11 is operated. The heating means 4 in the evaporating pot 1 is heated to a predetermined temperature by the action of the refrigerant flowing through the operation of the compressor 11, and the cooling means 9 in the cooling pot 2 is cooled. On the other hand, since the cooling pot 2 and the evaporating pot 1 are depressurized through the ejector 3a by the operation of the pump 3b,
The waste liquid boils and evaporates at a temperature below its boiling point, for example 35°C.

The water vapor evaporated in the evaporating pot 1 enters the cooling pot 2 through the upper space, where it is cooled and condensed to form water droplets, which are stored in the bottom 2a of the cooling pot 2 and are removed from the pot by vacuum suction. It is collected in the collection container 10 that has been installed. As the waste liquid previously injected into the pot 1 decreases due to evaporation, the pumping means 7 operates to replenish the waste liquid, so that evaporation replenishment is repeated in the evaporation pot 1, gradually concentrating the waste liquid. The highly concentrated solidified components become slurry and are stored in a slurry reservoir 15 provided at the bottom.

[0022] If the temperature of the refrigerant flowing through the heating means 4 in the evaporator pot 1 becomes too high, the load on the heat pump circuit, particularly the compressor, will increase. This rise and fall in refrigerant temperature reacts as the temperature of the waste liquid, so it is constantly monitored by the liquid temperature detector 23, and if the detected temperature is higher than the reference value, the fan 13 of the refrigerant air cooling means 12 is driven to remove the refrigerant. Reduce temperature to appropriate temperature. As a result, if the temperature of the waste liquid drops too much, the fan 1 of the refrigerant air cooling means 12
3 is stopped to raise the liquid temperature. This makes it possible to always maintain the refrigerant temperature and, by extension, the waste liquid temperature at the required temperature and maintain a constant evaporation rate.

[0023] When the waste liquid concentration process is completed, the sealed slurry outlet 16 is opened and the slurry accumulated at the bottom of the evaporator 1 is transferred to the slurry recovery container 1.
Take it out at 9. At the time of taking out the slurry, the rotary blade 20 is rotated by the drive source 22, thereby efficiently taking out the slurry.

[0024]

As described above, the present invention uses the heat radiating section and the heat absorbing section of a heat pump circuit as a heating means for an evaporating pot that evaporates and concentrates an aqueous solution, and as a cooling means for a cooling pot that cools, condenses, and liquefies vapor. In an evaporative concentrator equipped with a depressurizing means that communicates a pot and a cooling pot to reduce the pressure of the entire body, an air cooling means for forced air cooling of the refrigerant by a fan is provided at an appropriate location in the heating area of the heat pump circuit, and the fan is connected to the inside of the evaporating pot. Equipped with a liquid temperature detector that detects the temperature of the concentrated liquid and controls it based on the detected temperature, and if the temperature of the concentrated liquid falls below the reference value, the fan is stopped (or the fan air volume is weakened) to lower the refrigerant temperature. If the temperature of the concentrated liquid increases, the fan can be driven (or the fan's air volume can be increased) to lower the refrigerant temperature. It can be operated at a constant evaporation rate with any aqueous solution or in any environment without applying any heat, improving processing efficiency and extending the life of the compressor. It is effective.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the evaporation concentration device of the present application.

FIG. 2 is a schematic diagram showing the operation of the evaporation concentration device of the present invention.

FIG. 3 is a schematic diagram showing the installation position of air cooling means.

[Explanation of symbols]

1 Evaporation pot 2 Cooling pot 3 Pressure reduction means 3a Ejector 3b Pump 4 Heating means 5 Heat pump 6 Storage tank (container) 7 Pumping means 8 Baffle plate 9 Cooling means 10 Condensed water collection container 10a Overflow water storage container 11 Compressor 12 Air cooling means 13 Fan 14 Capillary tube 15 Slurry reservoir 16 Slurry outlet 17 Plug means 18 Handle 19 Slurry collection container 20 Rotating vane 21 Drive source 22 Output shaft 23 Liquid temperature detector 23a Sensor 24 Control means A, B, C Installation location of air cooling means

Claims (3)

[Claims] Claim 1: Using a heat radiating part and a heat absorbing part of a heat pump circuit as a heating means for an evaporation pot that evaporates and concentrates an aqueous solution and a cooling means for a cooling pot that cools, condenses, and liquefies vapor,
In an evaporative concentrator equipped with a depressurizing means for communicating the evaporating pot and the cooling pot and reducing the overall pressure, an air cooling means for forced air cooling of the refrigerant by a fan is provided at an appropriate position in the heating area of the heat pump circuit, and An apparatus for evaporating and concentrating an aqueous solution, comprising: a liquid temperature detector that detects the temperature of a concentrated liquid; and a control means that controls the fan according to the temperature detected by the liquid temperature device. 2. The aqueous solution evaporation concentration device according to claim 1, wherein the air cooling means is installed between a compressor of a heat pump circuit and a heat radiation section constituting a heating means of an evaporation pot. 3. The apparatus for evaporating and concentrating an aqueous solution according to claim 1, wherein the aqueous solution to be concentrated is a photographic processing waste liquid.