JP3023687B2 - Method and apparatus for evaporative concentration of photographic processing waste liquid - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for improving a concentration rate and a thermal efficiency in evaporative concentration of a photographic processing waste liquid.

BACKGROUND OF THE INVENTION Generally, photographic processing of silver halide photographic light-sensitive materials is carried out by developing, fixing and washing with black-and-white photographic materials, and color development and bleach-fixing (or bleaching and fixing with color photographic materials). ), A process using a processing liquid having one or more of functions such as water washing and stabilization.

In a photographic process for processing a large amount of photosensitive material, components consumed by the process are replenished, while components that are eluted or concentrated in the processing solution by the process (e.g., bromide ions in a developing solution, fixing solution). Means to maintain the performance of the processing solution constant by removing the processing solution components by removing the silver complex salt), and a replenisher is replenished to the processing solution for the above replenishment.
A part of the processing solution is discarded for removing the thickening component in the photographic processing.

In recent years, the replenisher has been changing to a system in which the amount of replenisher has been greatly reduced for pollution and economic reasons, including washing water, which is a replenisher for washing, but wastewater for photographic processing has been removed from the processing tanks of automatic developing machines. It was guided by a waste liquid pipe, diluted with a waste liquid of washing water, cooling water of an automatic developing machine, and the like, and disposed of in a sewer.

However, due to the recent tightening of pollution regulations, washing water and cooling water can be disposed of in sewers and rivers. However, other photographic processing solutions [eg, developing solutions, fixing solutions, color developing solutions, bleach-fixing solutions] (Or bleaching solution, fixing solution), stabilizing solution, etc.]
Has become virtually impossible to dispose of. For this reason, each photographic processing company asks a specialized waste liquid processing company to collect the waste liquid by paying a collection fee, and installs pollution treatment equipment. However, the method entrusted to a waste liquid treatment company requires a considerable amount of space for storing the waste liquid, and is extremely expensive in terms of cost. Furthermore, pollution treatment equipment requires initial investment (initial cost). It is extremely large and has drawbacks such as requiring a fairly large area for maintenance.

More specifically, as a pollution treatment method for reducing the pollution load of the photographic processing waste liquid, an activated sludge method (for example, JP-B-51-12943 and JP-B-51-7952, etc.) and an evaporation method (Japanese Patent Laid-Open No. Nos. 49-89437 and 56-33996, etc.) and electrolytic oxidation method (JP-A-48-84462, JP-A-49-119458, JP-B-53-434).
No. 78, JP-A-49-119457, etc.)
51-37704, JP-A-53-383, JP-B-53-43271, etc., reverse osmosis method (JP-A-50-22463, etc.), and chemical treatment methods (JP-A-49-64257, JP-B-49257) No. 57-37396,
No. 12152, No. 49-58833, No. 53-63763, JP-B-57-3
No. 7395) are known, but these are not yet sufficient.

On the other hand, due to restrictions on water resources, rising water supply and drainage costs, simplicity in automatic processor equipment, and the work environment around the automatic processor, etc. In recent years, photographic processing using an automatic developing machine (so-called anhydrous washing automatic developing machine) that does not require piping for supplying and draining water has been spreading. In such processing, it is desired that cooling water for controlling the temperature of the processing liquid is also omitted. In such photographic processing that does not substantially use washing water or cooling water, the pollution load is extremely large because the photographic processing waste liquid from the automatic developing machine is not diluted with water as compared with the case where there is a photographic processing waste liquid. is there.

Therefore, since the amount of the waste liquid is small, it is possible to omit the external piping for the supply and the waste liquid, which makes it difficult to move after the installation because the piping which is considered to be a drawback of the conventional automatic developing machine is installed. The space is small, the piping work at the time of installation requires a great deal of cost, the disadvantages such as the need for energy for hot water supply pressure are eliminated, and the compactness and simplification are achieved until it can be used as an office machine. Benefits are demonstrated.

However, on the other hand, the effluent has an extremely high pollution load, and the effluent is becoming completely impossible in rivers and even sewers in light of the pollution regulations. Furthermore, although the amount of waste liquid in such photographic processing (processing using a large amount of running water and not washing with water) is small,
For example, even a relatively small color processing lab can
About.

Therefore, it is generally collected by waste liquid recovery companies, and secondary and tertiary treatment is performed to make it harmless.
In a mini-lab or the like, the collection efficiency is low, so that it is difficult to have them come to the collection, and there is a problem that the store is filled with waste liquid.

On the other hand, in order to solve these problems, the photographic processing waste liquid can be easily processed in a mini lab, etc.
It has been studied to heat photographic processing waste liquid to evaporate water to dryness or to solidify it, for example, as disclosed in Japanese Utility Model Laid-Open No. 60-70841. According to the study by the inventors, when photographic processing waste liquid is evaporated, harmful or extremely odorous gases such as sulfurous acid gas, hydrogen sulfide, and ammonia gas are generated. This is commonly used as a fixer or a bleach-fixer for photographic processing solutions such as ammonium thiosulfate and sulfite (ammonium salt,
(Sodium salt or potassium salt) is generated by decomposition due to high temperature. Further, during the evaporating process, the water and the like in the photographic processing waste liquid are vaporized and gasified to expand the volume and increase the pressure in the evaporator. For this reason, the pressure causes the harmful or odorous gas to leak out of the evaporating apparatus to the outside of the harmful or odorous gas apparatus, which is extremely unfavorable in working environment.

In order to solve these problems, Japanese Utility Model Laid-Open No. 60-70841 discloses a method in which an exhaust gas treatment section such as activated carbon is provided in an exhaust pipe of an evaporative treatment apparatus. However, this method has a serious drawback in that water vapor due to a large amount of water in the photographic processing waste causes condensation or condensation in the exhaust gas processing section, and the water absorbs the gas-absorbing agent and instantaneously loses the gas-absorbing ability. Therefore, it was not yet practically usable.

In order to solve these problems, the present applicant has provided cooling condensing means for condensing vapor generated by evaporation when evaporating photographic processing waste liquid, further processing condensed water generated by condensing, and adding non-condensable components. A method and an apparatus for treating a photographic processing waste liquid which is also processed and discharged to the outside have been previously proposed.

However, according to the above proposal, it has been found that there are the following problems. That is, the steam generated by the evaporating process is condensed by the cooling and condensing means, but if the cooling and condensing efficiency is low, the ratio of the steam that is not condensed and released to the outside of the device increases, and even if the steam is treated with activated carbon,
The rate at which odorous and harmful gases are released to the outside of the device also increases. Furthermore, condensed water condensed by the cooling condensing means,
Even if it is treated with activated carbon, there are cases where the pollution load at the time of disposal is so high that it cannot be discharged to sewage or the like.

Further, in a minilab, the space in a store is extremely limited, and not only is the odor generated by processing the photographic processing liquid particularly problematic, but also the installation space of the waste liquid processing apparatus itself. Also, the price and running cost of the apparatus are important issues. Therefore, a compact, inexpensive, low-cost, high-concentration processing apparatus that can process photographic wastewater without generating odorous and harmful gas is desired. Have been.

[Problems to be solved by the invention]

As described above, it is necessary to immediately evaporate and concentrate the photographic processing waste liquid on demand in the vicinity of the automatic processing machine. However, it is not advisable to use conventional heating with electric heating because power consumption is large and it is not advisable to solve the problem.
By using a heat pump as proposed in 1301 and using the heating and cooling parts for heating for evaporative concentration and cooling of generated steam and generated gas, the power consumption was reduced to 50% or less and the power consumption was considerably reduced. . However, the lab consumes a large amount of power not only for evaporating and concentrating the photographic processing waste liquid but also for controlling the temperature of each processing liquid of the automatic processing machine and heating or cooling the drying unit. Looking at this comprehensively,
There is a demand for reduction of heating and cooling power. In particular, if it consumes more than 30A of electricity, the cost of the incoming wiring will be considerable.

In view of the above, it is an object of the present invention to provide a method and an apparatus for evaporating and concentrating photographic processing waste liquid, which further increase the thermal efficiency and improve the processing capacity in evaporating and concentrating the photographic processing waste liquid.

[Means for Solving the Problem] This object is achieved by the following (a), (b), (c), (d),
This can be achieved by any one of the means (e).

(A) A method for evaporating and concentrating a photographic processing waste liquid by heating and evaporating and concentrating a photographic processing waste liquid by using a heat pump, and cooling and condensing the resulting vapor to liquefy the photographic processing waste liquid. PH value of photographic processing waste solution to 4.
A method for evaporating and condensing photographic processing waste liquid, wherein the evaporation is promoted by adjusting the concentration to 5 to 7.5.

(B) A method for evaporating and condensing photographic processing waste liquid, wherein the evaporation and the cooling and condensation of the vapor in the method (a) are performed under reduced pressure.

(C) The method for evaporating and concentrating a photographic processing waste liquid according to the above item (a) or (b), wherein a developing waste liquid is used as the pH value adjusting agent.

(D) an evaporative concentration column for evaporating and concentrating photographic processing waste liquid by a heating unit of a heat pump, means for condensing vapor by a cooling unit of the heat pump in a condensing unit communicating therewith, and means for supplying photographic processing waste liquid into the column And a means for supplying a pH adjusting agent, and an evaporation promoting means for adjusting the pH value of the photographic processing waste liquid containing the fixing component to 4.5 to 7.5 by the pH adjusting agent. Evaporation concentrator.

(E) The apparatus for evaporating and condensing photographic processing waste liquid according to the above mode (d), further comprising a decompression means for depressurizing the evaporating and concentrating column and the condensing section communicating therewith.

Thus, the applicant of the present invention has determined the pH of the photographic processing waste liquid during evaporation and concentration.
It has been found that the evaporative concentration rate can be improved by defining the range.

By the way, the present applicant has disclosed in JP-A-63-149391 that
The pH of the photographic processing waste liquid at the time of evaporation and concentration was maintained at 3 to 11, and the decomposition of thiosulfate in the waste liquid was successfully prevented, and the generation of odor was extremely suppressed. The present invention is based on the experimental results of the present applicant who have further advanced research and development and have been able to drastically improve the rate of evaporation and concentration by keeping the pH at 4.5 to 7.5.

〔Example〕

First, in finding the method of the present invention, the following experiment was carried out using an evaporating and concentrating apparatus as schematically shown in FIG.

EXPERIMENTAL EXAMPLE 1 Commercially available ASA100, 400 films made by Konica, Fujifilm and Kodak as color negative films were processed according to the following processing process specifications and processing solution specifications.

However, two tank counter currents (45 seconds, 2
Tank) and 3 stabilization tanks counter current (20 seconds,
(3 tanks).

 The composition of the processing solution used is as follows.

[Color developing tank solution] potassium carbonate 30 g sodium hydrogen carbonate 2.5 g potassium sulfite 4 g sodium bromide 1.3 g potassium iodide 1.2 mg hydroxylamine sulfate 2.5 g sodium chloride 0.6 g 4-amino-3-methyl-N-ethyl-N -(Β-hydroxylethyl) aniline sulfate 4.8 g Potassium hydroxide 1.2 g Add water to make 1 and adjust to pH 10.06 with potassium hydroxide or 50% sulfuric acid.

[Color developing replenisher] potassium carbonate 40 g sodium hydrogen carbonate 3 g potassium sulfite 7 g sodium bromide 0.5 g hydroxylamine sulfate 3.1 g 4-amino-3-methyl-N-ethyl-N- (β-hydroxyethyl) aniline sulfate 6.0 g Potassium hydroxide 2 g Add water to make 1 and adjust to pH 10.12 with potassium hydroxide or 20% sulfuric acid.

[Bleaching tank liquid] 1-3- Ferric ammonium ammonium propylenediaminetetraacetate 150 g Acetic acid (90% aqueous solution) 50 m Ammonium bromide 150 g Add water to 1 and adjust to pH 4.4 using ammonium water or glacial acetic acid. .

[Bleaching replenisher] The bleach tank solution was adjusted to pH 4.2 with acetic acid.

[Fixing tank solution and replenishment] Ammonium thiosulfate 250 g Ammonium sulfite 20 g Exemplified [A'-7] (ammonium salt) 2 g Add water to 1 to adjust pH to 1 using acetic acid and ammonia water.
Adjust to 6.8.

[Stable tank solution and replenisher] Formaldehyde (37% solution) 1m 5-Chloro-2-methyl-4-isothiazoline-3-
On 0.05 g Emulgen 810 1 m Formaldehyde sodium bisulfite adduct sodium 2 g Water was added to adjust to 1 and adjusted to pH 7.0 with ammonium water and 50% sulfuric acid.

Further, the color paper was treated with the following treatment steps and treatment liquid.

Processing temperature Temperature Replenishment amount Number of tanks (1) Color development 38 ° C 30 seconds 200m / m ² 1 tank (2) Bleaching and fixing 33 ° C 25 seconds 100m / m ² 1 tank (3) Stabilization 33 ° C 30 seconds 500m / m ² Three tanks (Note 1) (Note 1) The three-layer method is a counter current method.

Processing solution composition [Color developing tank solution] Triethanolamine 10 m Potassium sulfite 0.2 g Sodium chloride 1.5 g Potassium carbonate 32.0 g 3-Methyl-4-amino-N-ethyl-N- (β-methanesulfonamidoethyl) -aniline sulfate Salt 5.5 g Optical brightener (diaminostilbene) 1.0 g Diethylhydroxylamine 5.0 g Diethylenetriaminepentaacetic acid 3.0 g Potassium bromide 2 mg 1,2-Dihydroxybenzene-3,5-disulfonic acid-sodium salt 0.2 g Add water The total amount is set to 1 and the pH is adjusted to 10.15 with KOH and H ₂ SO ₄ .

[Color developing replenisher] The amount of 3-methyl-4-amino-N-ethyl-N- (β-methanesulfamidoethyl) -aniline sulfate in the color developing tank solution was set to 7.0 g /, and potassium bromide was eliminated. And p
The H value is set to 10.60.

[Bleaching and fixing tank solution and replenisher] Ethylenediaminetetraacetic acid ferric ammonium dihydrate 60 g Ethylenediaminetetraacetic acid 3 g Ammonium thiosulfate (70% solution) 140 m Ammonium sulfite (40% solution) 27.5 m Potassium carbonate or glacial acetic acid at pH 5.8 And adjust the total amount to 1 by adding water.

[Stabilizing tank and Replenisher] 1-hydroxyethylidene-1,1-diphosphonic acid _{2g Bicl 3 0.3g ZnSO 4 · 7H} 2 O 0.7g fluorescent whitening agent (diamino stilbene) 1.0 g Keison WT (Note) 0.5 g ( Note: Made by Rohm and Haas Co., Ltd. The waste liquid obtained by the above treatment is mixed together with all of the negative paper, and the pH is changed. , And the wastewater treatment speed at that time was measured.

In the above measurement, the amount of waste liquid decreasing was measured every 30 minutes, and the average value of 2 hours was taken.

 Table 1 shows the results.

Next, in Experimental Example 2, the photosensitive material under the following conditions and the pH of the processing waste liquid obtained in the processing step were variously changed and adjusted, and the concentration was performed using the same evaporative concentration apparatus as in Experimental Example 1 to reduce the concentration rate. It was measured.

Experimental Example 2 (Photosensitive Material) Konica Konica RST clear light contact film CRHE manufactured by Konica was subjected to normal exposure, and processed with the following processing solutions and processing steps.

[Developer solution formulation] Hydroquinone 25 g 1-phenyl-4,4 dimethyl-3-pyrazolidone 0.4 g Sodium bromide 3 g 5-methylbenzotriazole 0.3 g 5-nitroindazole 0.05 g Diethylaminopropane-1,2-diol 10 g Potassium sulfite 90 g Potassium carbonate 30 g Sodium hydroxyethylenediamine triacetate 2 g Finished with water.

 The pH was adjusted to 10.2 with caustic soda.

[Formulation of fixing solution] (Composition A) Ammonium thiosulfate (72.5% aqueous solution) 240m Sodium sulfite 17g Sodium acetate trihydrate 6.5g Boric acid 6g Sodium citrate dihydrate 2g Acetic acid (90% aqueous solution) 13.6m (Composition B) Pure water (ion-exchanged water) 17 m Sulfuric acid (50 w% aqueous solution) 3.0 g Aluminum sulfate (aqueous solution with an equivalent content of 8.1 w% in terms of Al ₂ O ₃ ) 20 g The above composition A and composition B in 500 m water when using a fixing solution And finished to 1 before use. The pH of this fixer is about 4.2.

[Development processing conditions] (Process) (Temperature) (Time) (Replenishment amount) Development 40 ° C 15 seconds 30m / 4 cuts Fixing 35 ° C 15 seconds 40m / 4 cuts Rinse Normal temperature 15 seconds Running water Discharged under such processing conditions The pH of the fixing waste solution was adjusted using the developed waste solution and the fixing waste solution. As the pH adjuster, a 10% aqueous solution of sodium hydroxide and the above-mentioned development waste liquid were used, and the same evaporating and concentrating apparatus as that used in Experimental Example 1 was used. The results were as shown in Table 2.

The evaporative concentration rate in this case was determined from the amount of waste liquid reduced after one hour of operation.

Here, an acid or alkali agent can be used as the pH adjuster.

That is, as an acidic pH adjuster, if the aqueous solution shows acidity, it can be used as a pH adjuster for lowering the pH of the waste liquid.

For example, inorganic acids such as sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, boric acid, carbon dioxide, and sulfamic acid, and carboxylic acids such as acetic acid, oxalic acid, citric acid, malonic acid, and tartaric acid; and amino acids such as ethylenediaminetetraacetic acid and nitrilotriacetic acid. In addition to polycarboxylic acids and organic phosphonic acids, there are acid salts such as sodium hydrogen sulfate.

On the other hand, if the aqueous solution shows alkalinity, the alkaline pH adjuster can be used as a pH adjuster for increasing the pH of the waste liquid.

For example, hydroxides of alkali metals or alkaline earth metals such as NaOH, KOH, LiOH, Ca (OH) ₂ , Mg (OH) ₂ , ammonium hydroxide, carbonate, silicate, phosphate, boric acid There are alkali metal salts of inorganic weak acids such as salts, alkali metal salts of organic acids such as sodium acetate, sodium citrate, organic carboxylate and organic phosphonate.

Further, the fixing solution for X-ray films and printing light-sensitive materials has a low pH, and the pH adjusting agent required to make the pH range of the present invention is alkaline, so that development waste solution can be used. It is. In this case, the procurement of a pH adjuster is not particularly necessary, which is preferable.

From the results of Experiments 1 and 2, the pH of the photographic processing waste liquid supplied for evaporation and concentration may be adjusted to 4.5 to 7.5, more preferably 5.0 to 7.0, and most preferably
It can be said that it is 5.2-6.2.

Here, the pH of the treatment waste liquid is adjusted to 4.5 to 7.5 by adjusting the pH of the waste liquid to a pH adjusting agent before supplying the waste liquid to the evaporation concentration column, or a system for supplying the waste liquid into the column. Separately, a system for supplying a pH adjusting agent may be provided to adjust the pH to 4.5 to 7.5 in the column.

A first embodiment of an evaporative concentration apparatus using the method of the present invention will be described with reference to the schematic diagram of FIG.

A photographic processing waste liquid is injected and stored in a vacuum evaporation column (hereinafter simply referred to as a column) 1 which can withstand reduced pressure.
A decompression means 7 is connected to the upper vapor condensing section 5 to reduce the pressure. It is known that boiling occurs at a temperature lower than the boiling point under a reduced pressure lower than the atmospheric pressure. In this embodiment, evaporation at a low temperature at which gas generation hardly occurs is performed under the reduced pressure. Next, 3
A heating means 2 having a two-dimensional arrangement is provided.
The lower part is immersed in the photographic waste liquid storage part 4 so as to heat the photographic processing waste liquid, and the upper part thereof is in the air protruding from the photographic processing waste liquid storage part. From the waste liquid storage tank 31 and the pH adjustment liquid storage tank 75 by means of the liquid supply means 3, 3 'by the electromagnetic valves 6A and 76, and adjusted so that the waste liquid pH in the column enters 4.5 to 7.5. In addition to heating and evaporating under reduced pressure, heating and evaporating during the spraying and dropping process are repeated to efficiently and rapidly concentrate.

The water evaporated here contributes to compactness and stabilization of the pressure in the column by providing a cooling means 8A, a condensed water guide and a water receiver 8C at the upper part in the column 1. On the other hand, a component solidified to a high concentration by repeating the above evaporation and concentration is received and collected in a container 12 connected to a lower portion of the column 1. In the present invention, the heating means 2 is three-dimensionally arranged in the liquid and in the air because the part in the liquid mainly preheats the photographic processing waste liquid, and the part in the air has a large contact area with the photographic processing waste liquid sprayed and dropped thereon. This is effective in uniformly and efficiently performing low-temperature evaporation without gas generation. Further, a cooling means 8A is provided in the upper part of the column 1 so as to capture the water vapor rising from the lower part, cool and condense the water vapor, and collect it as water droplets. This has the effect of reducing the decompression balance in the column 1 due to the generated steam and reducing a large load to maintain a specified decompression state in the decompression device 7 (in this embodiment, an ejector is used). . That is, the place where the pressure in the column 1 rises due to the generated steam is immediately cooled and condensed to suppress the pressure rise.

In this configuration, assuming that the submerged portion of the heating means 2 is at the optimum temperature for the reduced-pressure evaporation, the portion in which the heating means 2 is in the air at the same temperature is also managed. The actual surface temperature of the portion of the photographic processing liquid becomes high, and when the photographic processing liquid is in contact with the photographic processing liquid, unpleasant gas is generated due to rapid heating. The means may be controlled to a temperature equal to or lower than the gas generation temperature, or the heating means may be separately controlled in the liquid or outside the liquid to an appropriate temperature.

Further, the heating means 2 and the cooling means 8A may be any of known techniques, but a heat pump is used in the present invention. Then, water vapor comes into contact with the surface of the cooling means and condenses to form water droplets, which travels through the cooling means 8A and is collected in the water recovery container 9. The surface temperature of the heating means is preferably 10
It is most preferably 0 ° C or lower, particularly preferably from 20 ° C to 60 ° C.

The heat radiating part of the heat pump is used as the heating means 2, and the heat absorbing part of the heat pump is used as the cooling means 8 A and the cooling means 8 B provided in the water recovery container 9.

A charge pipe 25 for charging a condenser of a heat pump constituting the heating means 2 and a capillary tube serving as an expansion valve provided after the heating means 2
26, a compressor 21 for a refrigerant disposed on the out side of the cooling means 8A, an air-cooled condenser 22 for air-cooling and condensing the refrigerant, and a fan 24 and a fan motor 23 of the column 1
Is placed outside.

Further, the refrigerant evaporator of the upper vapor condensing section 5 in the column 1 is connected to the cooling means 8B in the water recovery container 9 from the capillary tube 26 through the condenser of the heating means 2 and further extended as cooling means 8A. Is connected to the compressor 21 outside the column 1.

The cold water in the water recovery container 9 is supplied to a water circulation pump (P-
2) The water connected to the decompression device (ejector) 7 by 33 and drawn through the pipe 34 from the condensate recovery port 8C of the vapor condenser 5 at the top of the column 1 is put into the water recovery container 9 and simultaneously the pressure in the column 1 is reduced. To do.

Water overflowing from the water recovery container 9 is sent to a water tank 35 by a pipe 36. And this is drained to sewage.

Then, the processing waste liquid into the column 1 is stored in a container (waste liquid storage tank).
Sent from 31 by electromagnetic valve 6A as appropriate.

In this way, a relatively simple heat pump liquefies a large amount of vaporized vapor and a small amount is exhausted from the exhaust port 36, so that odor is completely prevented.

Although the evaporative concentration apparatus of the present embodiment is as described above, when considering only the thermal efficiency and the concentration rate without considering the generation of odor and the like, almost the same as when the pressure is reduced even when the pressure reducing apparatus is stopped. Obtain thermal efficiency and concentration rate. However, in this case, the processing waste liquid and the pH adjustment liquid are supplied from the containers 31 and 75 to the column 1
It is necessary to use a pump instead of the electromagnetic valves 6A and 76 to pump in.

The amount and time of replenishment of the photographic processing waste liquid into the column 1 are determined based on detection information of the level sensor (LC) 64.

Next, a second embodiment of the evaporative concentrator used in the method of the present invention will be described with reference to the schematic diagram of FIG. The components having the same functions as those of the first embodiment will be described using the same symbols.

Two columns 1 capable of withstanding decompression have liquid retaining portions 4
And a heating section 2A of the heat pump and a liquid pumping belt 51 from the liquid storage section 4 are provided independently of each other. A water reservoir 8C is provided. A cooling unit 8A of a heat pump is provided in the steam condensing unit 5, and a portion communicating with the upper portion of the column 1 is provided above the cooling unit 8A, and an air passage 44 communicating with a high-temperature duct 41 for the upper steam is provided below. Have been. A heating section 2C of the heat pump and a fan 42 are provided in the duct 41, and the air including the remaining part of the steam that has entered from above the cooling section 8A and has been cooled is passed through the air passage.
The air is circulated to the column 1 by the fan 42 through the duct 41 via 44, and the heating unit 2C acts together with air during the circulation to increase the temperature.

A heating unit 2B of the heat pump is provided outside the liquid reservoir 4 in the column 1 in series with the heating unit 2A.

Thereby, each waste liquid on the belt circulated while being pumped by the pumping belt 51 is immediately evaporated by a part of the heating steam in the duct 41 and the help of the heating air, thereby improving the evaporation and condensation efficiency. Will go.

A heat pump is used as a heat source and a cooling source,
The high-pressure heating refrigerant compressed by the compressor 21 is supplied to the heating section 2
C, 2A, and 2B are connected in series, and out of the column 1, the fan 66
Capillary tube acting as expansion valve while being cooled
The gas is vaporized through 26, and the cooling unit 8A is taken out and returned to the compressor 21 described above.

Although the decompression means is omitted in FIG. 2, it is more preferable to provide it in the same manner as in the first embodiment in order to prevent the odor from evaporating. However, when the odor or the like is not taken into account, the pressure reducing means is not particularly required.

In this embodiment, the photographic processing waste liquid and pH
The liquid supply of the adjusting agent is carried out from containers 63 and 73 by pumps (P) 62 and 72 through the pipes of the liquid supply means 3 and 3 ', and the supply ports 61 and 71 of the pipes are set at the upper part of the column 1. This is performed under the condition shown in FIG.

The amount and time of replenishment are determined based on detection information of the level sensor (LC) 64.

The pH of the photographic processing waste liquid is known in advance, and the pH of the pH adjuster is also known in advance.
The amount of replenishment into the two columns for obtaining the pH is determined by itself, and it is easy to accommodate a waste solution having a desired pH in the column.

〔The invention's effect〕

In evaporative concentration of the photographic processing waste liquid, the pH of the waste liquid is 4.5.
The method and apparatus of the present invention, which adds a pH adjuster to ~ 7.5, greatly improved the rate of evaporative concentration. Therefore, the energy efficiency improved by using the heating unit and the cooling unit of the heat pump as the heating source for evaporative concentration and the cooling source for vapor condensation, respectively, has been greatly improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a first embodiment of the evaporative concentration device of the present invention, and FIG. 2 is a schematic diagram of a second embodiment of the evaporative concentration device of the present invention. 1 Evaporation concentration column 2, 2A, 2B, 2C Heating section of heat pump 3, 3 'Liquid supply means 4, Liquid pool section 5 Condensing section, 6A, 76 Electromagnetic valve 8A … Heat pump cooling unit 21… Compressor, 31, 63… Waste liquid storage tank (container) 41… High temperature duct, 42, 66… Fan 51… Pumping belt, 61, 71… Tip supply port 62, 72 …… Pump, 73,75 …… pH adjustment liquid storage tank

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C02F 1/04 B01D 1/00

Claims (5)

(57) [Claims] 1. A method for evaporating and concentrating a photographic processing waste liquid by heating and evaporating and concentrating a photographic processing waste liquid using a heat pump, and cooling and condensing the resulting vapor to liquefy.
A method for evaporating and concentrating photographic processing waste liquid, comprising supplying a pH adjuster to adjust the pH value of the photographic processing waste liquid containing a fixing component to 4.5 to 7.5 to promote evaporation. 2. A method according to claim 1, wherein the evaporation and the cooling and condensing of the vapor are performed under reduced pressure. 3. The method for evaporating and condensing photographic processing waste liquid according to claim 1, wherein the pH value adjusting agent uses a developing waste liquid. 4. An evaporative concentration column for evaporating and condensing photographic processing waste liquid by a heating section of a heat pump, means for condensing vapor by a cooling section of the heat pump in a condensing section communicating with the column, and supplying photographic processing waste liquid into the column. And a means for supplying a pH adjuster, and the pH adjuster adjusts the pH value of the photographic processing waste liquid containing the fixing component to 4.5.
An evaporating and concentrating apparatus for waste photographic processing liquid, comprising: an evaporation promoting means for adjusting the concentration to 7.5. 5. An apparatus for evaporating and condensing photographic processing waste liquid according to claim 4, further comprising a decompression means for reducing the pressure of said evaporating concentration column and a condensing section communicating therewith.