JPH0422484A - Evaporative concentration treatment system for waste photographic processing solution - Google Patents

Abstract

PURPOSE:To prevent the generation of malodorous gas by preventing the opening area of one of stock tanks storing a waste solution in a separated state from becoming 500cm<2>/l or more and guiding the waste solution to an evaporative concn. container at 90 deg.C or lower. CONSTITUTION:The waste developing solution of a color negative automatic developing machine 41 is introduced into a developing solution stock tank 43 and other waste solution is introduced into a stock tank 44. The waste developing solution of a color paper automatic developing machine 42 is introduced into a developing solution stock tank 43 and other waste solution is introduced into a stock tank 44. As mentioned above, the waste solutions of a different kind of the automatic developing machines are respectively mixed by development and the others to be introduced into the stock tanks 43, 44, and float lids 46, 47 are provided to the tanks 43, 44 so as to follow the lowering of liquid levels even when the stock amounts of the waste solutions are reduced to prevent an extreme increase in the open areas of the tanks. At least one of the stock tanks 43, 44 is set so that the open area of the waste solution does not become 500cm<2>/l or more and the waste solution is guided to an evaporative concn. apparatus 45 at 90 deg.C or lower from the stock tank.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a method for evaporating waste liquid (hereinafter referred to as photographic processing waste liquid or waste liquid) generated during the processing of photographic light-sensitive materials using an automatic photographic processor. Processing equipment! This invention relates to a processing apparatus for photographic processing waste liquid, which is suitable to be disposed in or near an automatic processor.

[Conventional technology]

Generally, photographic processing of silver halide light-sensitive materials is carried out in the order of color development, bleach-fixing (or bleaching and fixing), and water washing or stabilization processing.

In photographic processing in which a large amount of light-sensitive material is processed, components consumed during processing are replenished, while components that are eluted into the processing solution or concentrated by evaporation during processing (for example, bromide ions in the developer, bromide ions in the fixer), etc. A method is used to maintain the performance of the processing solution at a constant level by removing substances such as silver complex salts (such as silver complex salts) and keeping the processing components constant. A portion of the processing solution is discarded to remove concentrated components.

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 significantly reduced due to pollution and economic reasons, but photographic processing waste fluid is removed from the processing tank of automatic processors. It is led through a waste liquid pipe, diluted with waste liquid from washing water, cooling water from automatic processing machines, etc., and then disposed of in a sewer or the like.

However, due to stricter pollution regulations in recent years, it is possible to dispose of washing water and cooling water into sewers or rivers, but other photographic processing solutions [e.g. developer, fixer, color developer, bleach-fixer] (or bleaching solution, fixing solution), stabilizing solution, etc. 1 is virtually impossible to dispose of. 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.
ing. However, the method of outsourcing to a waste liquid treatment company requires a considerable amount of storage space to store the waste liquid, is extremely expensive, and requires an initial investment (('Ni) for pollution treatment equipment. It has drawbacks such as extremely high cost (cost) and the need for a fairly large area for maintenance.

Therefore, waste liquid is generally collected by a waste liquid collection company and rendered harmless through secondary and tertiary processing, but due to rising collection costs, the price of waste liquid collection is increasing year by year, and collection efficiency is low in minilabs, etc., so it is difficult to do so. No one can come to collect the liquid, causing problems such as waste liquid filling the store.

In order to solve these problems, research has been conducted into heating the photographic processing waste liquid to evaporate the water to dryness or solidify it, with the aim of making it easier to process the photographic processing waste liquid even in minilabs. It is shown in JP-A No. 60-70841 and the like. By the way, the inventors' research has shown that when photographic processing waste liquid is evaporated, harmful or extremely malodorous gases such as sulfur dioxide gas, hydrogen sulfide, and ammonia gas are generated. It has been found that this is caused by the decomposition of ammonium thiosulfate and sulfites (ammonium salt, sodium salt, or potassium salt), which are commonly used as fixing solutions and bleach-fixing solutions in photographic processing solutions, due to high temperatures. Furthermore, during the evaporation process, moisture and the like in the photographic processing waste liquid turns into steam and gasifies, causing the volume to expand and the pressure in the evaporator to increase. Therefore, due to this pressure, the harmful or malodorous gas leaks out of the evaporation treatment apparatus to the outside of the apparatus, resulting in an extremely unfavorable working environment.

Therefore, in order to solve these problems,
No. 1 discloses a method of providing an I7 gas treatment section such as activated carbon in the exhaust pipe section of an evaporation treatment device. However, this method has the serious drawback that water vapor from a large amount of water in the photographic processing waste liquid condenses or condenses in the exhaust gas treatment section, covering the gas absorption processing agent with moisture and instantly losing its gas absorption ability. However, it has not yet been put to practical use.

[Problem to be solved by the invention]

In order to solve these problems, the inventors decided to evaporate photographic processing waste by condensing the vapor generated by the evaporation, and then treating the condensate produced by the condensation as well as non-condensable components. We have previously proposed a device for concentrating photographic processing waste liquid that is then discharged to the outside.

There is a need to construct an efficient processing system using such a concentration processing apparatus for photographic processing waste liquid, which does not generate foul-smelling gas as a whole. Those skilled in the art have already conducted separate processing of the processing liquid and separated stock tanks, and the applicant has further determined that the oxidation of the processing liquid contributes significantly to the generation of malodorous sulfur-based gases. I discovered this and decided to use it as a powerful countermeasure against gas when photographic processing waste liquid is evaporated and concentrated.

In our research, we have established a technology that promotes evaporative concentration at low temperatures by performing the above evaporative concentration under reduced pressure. Sulfur-based gases have decreased significantly, but it is still insufficient.

An object of the present invention is to provide an evaporative concentration system for photographic processing waste liquid that does not generate foul-smelling gas.

[Means to solve problems]

The purpose is the following (1), (2), (3), (4), (
This can be achieved by any of the technical means of 5) and (6).

(1) The photographic processing waste liquid generated from each processing tank of an automatic photographic processor is stocked in at least two stock tanks, and at least the waste liquid generated from the development processing tank and other processing tanks are stored separately. At least one of the stock tanks should have an opening area of 500 cm2/(1 or more) for waste liquid, and the waste liquid from the stock tank should be
An evaporative concentration treatment system for photographic processing waste liquid, characterized in that the photographic processing waste liquid is led to an apparatus for evaporation concentration at 0° C. or lower.

(2) The opening area of all the above stock tanks is 500cm.
2. The evaporative concentration treatment system for photographic processing waste liquid according to item 1, characterized in that the IQ is lower than m''IQ.

(3) Evaporation of photographic processing waste liquid as described in item 1 or 2, characterized in that among photographic processing waste liquids generated from a plurality of automatic photographic processing machines, the developer is mixed and stocked in a developer stock tank. Concentration processing system.

(4) The evaporative concentration processing system for photographic processing waste liquid according to any one of items 1 to 3, wherein the evaporative concentration device performs the evaporative concentration under reduced pressure.

(5) The evaporative concentration processing system for photographic processing waste liquid according to any one of items 1 to 4, wherein the apparatus for evaporating and concentrating the photographic processing waste liquid uses a heating section of a heat pump as a heating means for the photographic processing waste liquid.

(6) The evaporative concentration processing system for photographic processing waste liquid according to any one of items 1 to 5, wherein the evaporative concentration is carried out separately for the developing solution and other waste liquid.

In this invention, assuming the conventional collection method in which photographic processing waste liquid is collected from an automatic processing machine into a waste liquid collection container in the form of an automatic flow of used liquid as new liquid is replenished, the above-mentioned method will be applied. Although the waste liquid is transferred from the waste liquid collection container to the stock tank, when the system of the present invention is introduced in earnest, the overflow waste liquid collection container from the automatic processor may be used as a stock tank.

The reason for stocking in two or more stock tanks is that when developer waste is mixed with other liquids, such as fixer waste, it reacts violently and generates toxic gas.
This is to avoid this.

The reason for storing waste liquid in a stock tank and making sure that its opening area does not exceed 500cm2/Q is that if the opening area is wide, the photographic processing waste liquid will quickly oxidize and become oxides during storage. This is to prevent Furthermore, as the amount of liquid in the container decreases, the open area that comes in contact with air increases per volume, which accelerates oxidation, so in order to prevent this, the opening area should not exceed the specified value.

The applicant has determined that the opening area is 500cm2/(1
! Preferably 200cm2/Q so as not to exceed
More preferably 100cm2/
(I discovered that it is effective to always keep it so that it does not exceed !).

The reason why evaporative concentration is carried out at 90°C or lower is to prevent decomposition of ammonium thiosulfate and sulfites contained in the photographic processing waste solution, and furthermore, by carrying out the evaporation under reduced pressure,
It brings out the effect of actively evaporating water even at temperatures below ℃.

The reason why the heating section of a heat pump is used as the heating means of the evaporation concentration device is that in order to stabilize the control of the heating section at 90°C or less and narrow the temperature ripple width, other heating means,
For example, we confirmed that the heating section of a heat pump is suitable for keeping the distribution of thermal energy over the surface area of the heating section low and preventing even one part of the photographic processing waste from over-ripening, something that is difficult to do with electric heaters. Because I did.

Furthermore, the opening area of the waste liquid in the stock tank is 500cm”/
Measures to prevent the problem from exceeding Q include installing a floating pipe on the waste liquid surface, using a flexible airtight container, and ensuring that the suction pipe does not reach the bottom of the stock tank and sucks only until the opening area is less than 500cm''/Q. There are ways to say that it cannot be released (Figure 5).

The relationship between evaporation temperature and hydrogen sulfide gas concentration is shown as an experimental result in Table vg1, which will be described later. The hydrogen sulfide gas concentration at 90° C. or lower in the embodiment of this invention is 1 ppm, and it is clear that this method is particularly effective compared to the others.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 2 is a block diagram of the evaporative concentration treatment system for photographic processing waste liquid according to the present invention, and FIG. 1 is a conventional diagram for comparison.

FIG. 3 and FIG. 4 show an embodiment of the evaporation concentration apparatus. The old automatic developing machine for color negatives is composed of developing (CD), bleaching (BL), fixing (FTX), and stabilization (ST), among which the developing waste liquid is put into the developer stock tank 43. Other waste liquid is put into the stock tank 44. On the other hand, the automatic developing machine 42 for color paper is composed of developing (CD), bleach-fixing (BF), and stabilization (SST), of which the developer waste is put into the developer stock tank 43, and the other waste solutions are stored. Put it in Tania 44. In this way, waste liquids from different types of automatic processors were separated into developing and other liquids, mixed together, and placed in a stock tank. And these stock tanks have 4 floating pigs.
6.47 is provided so that even if the stock liquid volume decreases, the floating pig will follow the drop in the liquid level and the opening area will not increase excessively.

In this example, the evaporation concentration device 45 shown in FIG. 3 was used.

The data obtained by measuring the hydrogen sulfide gas concentration when photographic processing waste liquid was concentrated 15 times using this system are shown in Table 1 below.

The temperature control in Table 1 is based on the change in air volume of the fan shown in FIG.

3, 11i'', the evaporative concentration column 50 is equipped with a heater 51, and the waste liquid is injected from the inlet 62 through the supply means 61 from the waste liquid stock tank 43 or 44 until the specified liquid level is detected by the liquid level sensor 52. The waste liquid that has been poured up to that point is kept silent, and the waste liquid adheres to the surface of the endless belt 53 that goes up and down in the liquid from above, and is lifted upwards and the wind blown by the ventilation fan 54 accelerates the evaporation of water, and the waste liquid is generated. The water vapor then enters a cooling condenser 56 where it is cooled by a fan 58 and the condensed water is collected from a lower drain 57 into a container 63. A sensor 55 is used to detect hydrogen sulfide in the generated vapor. was provided in the passage leading from the evaporative concentration column 50 to the cooling condenser 56.

FIG. 4 shows an embodiment of another evaporative concentration apparatus. In FIG. 4, when the water circulation pump 14 is started, the water pumped up from the container 16 is blown downward from the ejector 15 with great force. At this time, the air passages 23 connected in a single shape by the enoetater 15 become under negative pressure, so when the valve 18 is opened, the vapor condensation section 8 and the evaporation concentration column (hereinafter also simply referred to as column) connected to this are connected to the vapor condensation section 8. Air is sucked out from the air chambers 9), and these, the vapor condensing section 8 and the column 9, are depressurized.

Next, when the valve 20 is opened, the waste liquid is sucked up from the container 43 or 44 by the reduced pressure and sprayed into the column 9 through the nozzle 21 provided at the upper part of the column 9. When the waste liquid reaches the liquid level A in the column 9, the liquid level sensor 22 detects this and closes the valve 20 to stop the liquid injection.The valve 20 may be a solenoid valve.

Next, the heat pump 1 will be explained in detail. The heat pump 1 includes a compressor 2, an air-cooled condenser 3, a propeller 7 driven by a fan motor 5, a heating section 6, a cooling coil 13, a cooling section 7, and pipes connecting these. It consists of the refrigerant injected into the system.

The refrigerant compressed by the compressor 2 reaches a high temperature and is blown out toward the air-cooled condenser 3. Here, forced air cooling is performed using a propeller fan 4 driven by a fan motor 5. This is done in order to prevent the heat pump from running out of control, control the temperature of the heating section 6, and prevent gas generation due to high temperatures.

Next, the refrigerant that has reached an appropriate temperature due to the forced air cooling is heated to a heating section 6.
to go into. The heating unit 6 is also disposed continuously above the liquid level of the waste liquid injected into the column 9 below the liquid level A.
The part below heats the waste liquid, and the part above the liquid surface heats the generated steam.

The refrigerant that has passed through the heating section 6 passes through the dryer 11 and the gear pillar tube 10, enters the cooling coil I3, cools the water injected into the container 16, and then enters the cooling section 7. After cooling the vapor evaporated from the column 9, the refrigerant returns to the compressor 2 to complete the I cycle, and this cycle is repeated.

The features of this configuration are that the water blowing force of the water circulation pump is used as a pressure reduction means, and the water is cooled with the heat pump's refrigerant. By using a (condenser) to heat the steam not only below the liquid level but also above the liquid level, the upward movement of evaporated steam is accelerated and the evaporation efficiency is greatly improved. That's true.

Furthermore, as an efficiency design, by reducing the pressure in column 9 as described above,
When the valve 2o is opened, the waste liquid is pumped up into the column 9 without a liquid pump, which is effective for efficiency and compactness. When heating evaporation is performed under reduced pressure with the above configuration, a phenomenon occurs in which the waste liquid violently splashes upward from the waste liquid surface of the column 9. To prevent this from entering the cooling section 7, , a splash prevention plate 24 was provided.

The generated water vapor is cooled and condensed in the cooling unit 7 and collected as water droplets at the bottom 8C of the steam condensing unit 8, or is discharged into the container 16 through the valve 18 by pressure reducing means. and,
The container 16 is provided with an overflow port, and the water overflowing with the condensed water flows into the condensed water tank 35 through a pipe 36 and is collected.

As evaporation concentration progresses and the waste liquid becomes sludge,
There is a point where the balance of the cooling/heating cycle as described above suddenly collapses, and this is detected when the refrigerant temperature at the outlet of the compressor 2 after compression suddenly changes from 100°C to 120°C. Therefore, by detecting this temperature change with a temperature sensor, the compressor 2 is stopped and the water circulation pump 14 is stopped to detect that the waste liquid has turned into sludge.
stop.

At this time, since the container 16 is open to atmospheric pressure, the water in the container j6 flows into the air passage 23 due to the reduced pressure in the condensing section 8.
In order to prevent this, the valve 18 is designed as a three-way valve so that the air passage 2 is closed during the above-mentioned stop.
The third side is closed, leaving an opening to the atmosphere.

However, instead of a three-way valve, an electromagnetic valve or the like for opening and closing an opening communicating with the atmosphere may be provided in the air passage 23, and this may be opened to balance the atmospheric pressure at the same time as the mud stops.

Thereafter, the valve 25 at the bottom of the column 9 is opened to discharge the sludge through the IJ. The sludge collected here contains a high concentration of silver, so it is stored in a sealed container as a valuable resource.
The silver is collected separately and then disposed of in an appropriate location.

In addition, the concentration level with this device is 18 to 20 in total waste liquid.
It can be concentrated up to twice as much, and the sludge conversion rate is apparently 98%.

〔Effect of the invention〕

Rather than using these evaporative concentration devices for photographic processing waste liquid in a vacuum, the waste liquid generated from automatic processors is stored so as not to oxidize and is separated into water and a very small amount of sludge by evaporation concentration device. As a result, a waste liquid treatment system will be established that can significantly reduce the problem of waste liquid disposal and prevent the generation of harmful gases.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional example. FIG. 2 is a block diagram of one embodiment of the present invention. FIG. 3 is an explanatory diagram of one embodiment of the evaporation concentration device used in the present invention. FIG. 4 is an explanatory diagram of another embodiment of the evaporation concentration device used in the present invention. FIG. 5 is a sectional view of one embodiment of the stock tank. l... Heat pump 2... Compressor 3.
...Air-cooled condenser 4...Propeller fan 5...
Fan heater 6... Heating section (@condenser) 7... Cooling section (evaporator) 8... Steam condensing section 9... Heating section IO... Capillary tube 11... Dryer 13...・Cooling coil 14
...Water circulation pump 15...Ejector 16.
... Container 17 ... Pressure reduction means 18 ... Pal 7' 20 ... Valve 21 ... Nozzle 22 ... Liquid level sensor 23 ... Air path
24... Splash prevention plate 25... Valve 41... Automatic developing machine for color negatives 42... Automatic developing machine for color vapor 43, developer stock tank 44... Other waste liquid stock tank 45... Evaporative concentrator 4647...Floating pig 50...Evaporative concentration column 51...Heater 52...Liquid level sensor 53...Endless belt 54...Blower fan 55...Sensor 56
...Cooling condenser 57...Discharge port 58...Fan 59...Pipe 60...Waste liquid stock tank

Claims (6)

[Claims] (1) The photographic processing waste liquid generated from each processing tank of an automatic photographic processor is stocked in at least two stock tanks, and at least the waste liquid generated from the development processing tank and other processing tanks are separately stocked, and An evaporative concentration processing system for photographic processing waste liquid, characterized in that at least one of the stock tanks prevents the opening area of the waste liquid from becoming more than 500 cm^2/l, and leads the waste liquid from the stock tank to a device for evaporating and concentrating the waste liquid at 90° C. or lower. (2) The opening area of all the above stock tanks is 500cm.
2. The evaporative concentration treatment system for photographic processing waste liquid according to claim 1, characterized in that the concentration is less than m^2/l. (3) The photographic processing waste liquid according to claim 1 or claim 2, characterized in that among the photographic processing waste liquids generated from a plurality of automatic photographic processing machines, a developer is mixed and stocked in a developer stock tank. Evaporative concentration processing system. (4) The evaporative concentration processing system for photographic processing waste liquid according to any one of claims 1 to 3, wherein the evaporative concentration device performs evaporative concentration under reduced pressure. (5) The evaporative concentration processing system for photographic processing waste liquid according to any one of claims 1 to 4, wherein the evaporative concentration device uses a heating section of a heat pump as heating means for the photographic processing waste liquid. . (6) The evaporative concentration processing system for photographic processing waste liquid according to any one of claims 1 to 5, wherein the evaporative concentration is carried out separately for the developing solution and other waste liquid.