JPH0422481A - Apparatus for evaporative concentration treatment of waste photographic processing solution - Google Patents

Abstract

PURPOSE:To prevent the generation of an offensive smell and the clogging due to sludge during long-term operation by a method wherein air is blown in a waste photographic processing solution and a waste solution is introduced into a separation means and repeatedly circulated after separation to bring the circumference of a heating means to the atmosphere consisting of the waste solution and air. CONSTITUTION:The air cooled by a cooling cylinder 1 is sucked out to be blown in an evaporative concn. column 14 from a blowing port 15. A heater 16 is built in the evaporative concn. column 16 and an opening part 19 is set to a negative pressure by blowing pressure and a waste solution is sucked out to be blown in the evaporative column 14. The blown-out waste solution is heated by a heater 16 and passed through a spiral pipe 21 to be accelerated in evaporation while the contact surface thereof with air is increased to enter a separation chamber 22. A temp. sensor 23 is provided in the separation chamber 22 to set the temp. of the separation chamber 22 to a range of 90 deg.C or lower, preventing the generation of harmful gas and malodorous gas due to the thermal decomposition of the waste solution. A half partition 24 is provided and a concentrate or sludge is allowed to fall and again blown in the evaporative concn. column 14 to be repeatedly circulated. The waste solution from a waste solution container 31 is injected in a supply tower 34 in order to supply a new waste solution, and a part thereof is met with the flow-down liquid from the separation chamber 22 to be blown in the evaporative concn. column 14.

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. The present invention relates to a processing device, and particularly to a processing device for photographic processing waste liquid suitable for processing by being 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 dissolved into the processing solution or concentrated by evaporation (for example, bromide ions in the developer, bromide ions in the fixer, etc.) are replenished. A method is used to maintain the performance of the processing solution at a constant level by removing substances (such as silver complex salts) and keeping the processing components constant. A portion of the processing liquid 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 guided by the feeling of waste liquid, diluted with waste liquid from washing water, cooling water from automatic processing machines, etc., and disposed of in sewers, etc.

However, due to stricter pollution regulations in recent years, it is possible to dispose of washing water and cooling water into sewers and rivers, but other photographic processing solutions such as developer, fixer, color developer, bleach-fixer ( It has become virtually impossible to dispose of bleaching solutions, fixing solutions), stabilizing solutions, etc. 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.

However, the method of outsourcing to a waste liquid treatment company requires a considerable amount of space to store the waste liquid, is extremely expensive, and the initial investment (initial cost) for pollution treatment equipment is high. It has the disadvantage of being extremely large and requiring a fairly large area to maintain.

Therefore, waste liquid is generally collected by a waste liquid collection company and rendered harmless through secondary and tertiary processing.However, not only is the price of waste liquid collection increasing year by year due to rising collection costs, but 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 to heat 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, in research conducted by the present applicant, 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. Further, during the evaporation process, moisture and the like in the photographic processing waste liquid becomes vapor and gasifies, thereby expanding the volume and increasing the pressure in the evaporation pot. 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 exhaust 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 and causing it to instantly lose 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 present applicant condenses the vapor produced by evaporation when processing waste photographic processing liquid by evaporation, and further treats the condensate produced by condensation, and also treats non-condensed components. We have previously proposed a device for concentrating photographic processing waste liquid to be discharged to.

However, according to this proposal, the following problems were found. That is, if the evaporation concentration device is of a flash type having a heating means, the device may be damaged due to dry heating, or the device may become clogged with sludge, making it impossible to operate.

The present invention has been made in view of the above-mentioned drawbacks of the prior art, and it is an object of the present invention to provide an evaporative concentration device for photographic processing waste liquid that is odorless, can be operated for a long period of time, and is not clogged with sludge. .

[Failure to solve the problem]

The purpose is achieved by either (1) or (2) below.

(1) In a configuration in which photographic processing waste liquid is heated to evaporate and concentrated, and the generated vapor is cooled and condensed, air is blown into the photographic processing waste liquid, and the waste liquid is lifted by the air and the gas generated from the waste liquid. , after introducing the waste liquid into a separation means for separating the gas and the waste liquid, the separated waste liquid is returned to the air blowing section, thereby repeatedly circulating the waste liquid, and
An apparatus for evaporating and concentrating photographic processing waste liquid, characterized in that the heating means for heating is provided so that the waste liquid and gas are formed around it.

(2) The surface heat transfer amount of the heating means is 0.5 kcaQ-h.
r/cm'' to 50 kcaLhr/c+++', the cross-sectional area of the space around the heating means through which the waste liquid and gas pass is in the range from lc+++'' to 300 cm'', and the gas flow rate in the cross-section is 0. The apparatus for evaporating and concentrating photographic processing waste liquid according to item (1), characterized in that the rate is in the range of .5 m/sec to 50 m/sec.

In this invention, air is blown into the photographic processing waste liquid by
By scattering the photographic processing waste liquid with high-pressure air and heating it with a heating means while extremely increasing the contact surface with the air, the photographic processing waste liquid is heated evenly while preventing excessive temperature rise. This is to bring out the effect of making it easier for moisture to evaporate in the air.

With this configuration, the heating temperature of the photographic processing waste liquid by the heating means was 90°C or less, and evaporation and concentration could be carried out sufficiently and efficiently.

The temperature of the photographic processing waste liquid should be 90°C or less, more preferably 1
The reason why the temperature is controlled to be within the range of 5°C to 80°C is that within this range, the components of the photographic processing waste liquid will not be thermally decomposed, and therefore no bad odor or toxic gas will be generated.

In this invention, the reason why the evaporative concentration is repeated and circulated is that the main component in the waste liquid cannot be removed by one evaporation, so the degree of concentration is low and the fluidity is good, so recirculation is possible. This is because repeating the circulation has the advantage of being able to arbitrarily select the degree of concentration.In order to make this circulation possible, this invention solves clogging prevention by injecting new waste liquid, and increases the degree of concentration. The advanced high-concentration waste liquid is precipitated using the difference in specific gravity, and the upper layer of low-concentration liquid is circulated.

In this invention, air is blown into the photographic processing waste liquid, and a mixture of the air and the photographic processing waste liquid is moved by the pressure of the air and heated by a heating means, and the cross-sectional area of the moving space is 1 cm2 to 1 cm2. 300cm2, and the flow velocity moving in this area is 0.5m/sec-5
0 m/sec, more preferably 1 m/sec to 20 m/sec, particularly preferably 2n+/sec to 10 m/sec, to regulate heat transfer by the heating means, and as mentioned above, the photographic processing waste liquid is kept at 90° C. or lower, more preferably. is 15°C to 80°
C or less, and to prevent clogging due to sludge. The surface heat transfer amount of the heating means is also regulated in order to prevent excessive temperature rise of the photographic processing waste liquid, and a preferable range was shown.

Note that this amount of surface heat transfer is related to the above-mentioned moving flow velocity,
The combination of the two should be efficient as long as the temperature of the photographic processing waste liquid does not exceed 90°C (1 value for evaporation and concentration should be determined by the apparatus concerned).

〔Example〕

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

FIG. 1 is an explanatory diagram when a flash type evaporation concentration processing apparatus according to an embodiment of the present invention is used.

The cooling tower 1 has an upper bottom 2, an outlet 3, and a number of half partitions 6.
It consists of a bottom part 7 and an outer cylinder, and tap water is injected from above through a constant flow valve 5.

The water also flows downward through the outlet 3 and collides with the half partition 6 to form a shower. Since the inflow of tap water exceeds this flow rate, water accumulates on the upper bottom 2, and the liquid level sensor 4 controls the operation of the valve 9 to maintain it at a specified position. With this mechanism, water flows stably through the cooling cylinder l, and the cooling capacity is maintained.

The water that has flowed down collects on the bottom 7, and is drained by operating the pump 8 so as to maintain a specified height using the liquid level sensor IO. The air cooled by the cooling cylinder 1 is sucked out from the suction port 12 by the air pump 11, and is blown into the evaporative concentration column 14 from the blowing port 15.

The evaporative concentration column 14 has a built-in heater 16, and a bimetallic heater breaker 17 is provided on the outer wall to serve as a direct safety valve. Due to the above blowing pressure, the opening 19 of the adjacent pipe 27 becomes a negative pressure, so the waste liquid is sucked out from the flexible container 18 through the pipe 27 and blown into the evaporation concentration column 14 . The blown waste liquid rises while being heated by the heater 16, passes through the spiral tube 21, increases the contact surface with air, and enters the separation chamber 22 with accelerated evaporation. A temperature sensor 23 is installed in the separation chamber 22.
is installed to detect overheating and turn on the heater 16 to maintain a constant temperature. This temperature is 90°C or lower, which is within the range where the waste liquid does not thermally decompose and generate harmful gases or foul-smelling gases. , preferably from 15°C to 80°
Set between C.

The separation chamber 22 is provided with a half partition 24 to prevent water vapor from escaping and concentrated waste liquid or sludge from entering the air passages, so the concentrated liquid or sludge drips and accumulates at the bottom. It descends through the conduit from the lower port 25. Since this conduit joins the pipe 27 at the branch 26, the negative pressure caused by the air blowing through the air inlet 15 causes the pipe 27 to
and is again blown out into the evaporative concentration column 14.

However, the waste liquid or sludge, which has become heavier due to progress of concentration, is not suctioned by the negative pressure and falls into the flexible container 18. In this manner, the waste liquid is repeatedly circulated from the evaporative concentrator column 14 through the separation chamber 22 until the concentration proceeds. In order to newly supply waste liquid, the waste liquid sucked out from the waste liquid container 31 by the pump 35 is injected into the supply tower 347 and accumulates up to the position specified by the liquid level sensor 20.
The liquid flows from the bottom opening 30 through a tube to the branch 29, where it joins the flowing liquid from the separation chamber 22. The new waste liquid is then blown out from the branch 29 through the branch 26 and through the pipe 27 into the evaporative concentration column 14.

This configuration is to clean the pipes and the like to prevent them from becoming clogged with sludge by supplying new waste liquid, and to replenish the waste liquid that has decreased due to concentration and to perform continuous evaporation and concentration.

On the other hand, the steam from the separation chamber 22 passes through the outlet 32 and the pipe 33 and is blown out into the tower through the opening 13 at the bottom of the cooling tower 1 .

At this time, since water is accumulated in the lower part of the cooling tower 1, the steam is blown into the water, cooling and condensation is performed, and the condensed water joins with the water in the tower and is recovered.

Then, the dehumidified air is sucked out from the suction loe 2 again by the air pump 11. Initial supply of waste liquid is carried out by sucking out new waste liquid from the waste liquid container 31 using the pump 28 and injecting it into a branch 36 provided in the blowing path by the air pump 11.

〔Effect of the invention〕

With this configuration, it is possible to realize an apparatus that prevents excessive temperature rise when heating and evaporating and concentrating photographic processing waste liquid, does not generate bad odors or harmful gases, and does not destroy the apparatus due to clogging. It is.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an embodiment. l...Cooling tower 2...Upper bottom 3...Downstream port 4...Liquid level sensor 5...Constant flow valve
6...half partition 7...bottom 8...
・Pump 9...Valve 10...Liquid level sensor j1...Air pump ]2...Suction port 13
...Opening 14...Evaporation concentration column 15
...Blowing port 17...Breaker 19...Opening 21...Spiral tube 23...Temperature sensor 25...Lower port 27...Pipe 29...Branch 31...Waste liquid Container 33...pipe 35...pump 16...heater 18...flexible container 20...liquid level sensor 22...separation chamber 24...half partition 26...crossroads 28... Pump 30...bottom opening 32...outlet 34...supply tower 36...crossroads

Claims (2)

[Claims] (1) In a configuration in which photographic processing waste liquid is heated to evaporate and concentrated, and the generated vapor is cooled and condensed, air is blown into the photographic processing waste liquid, and the waste liquid is lifted by the air and the gas generated from the waste liquid. , after introducing the waste liquid into a separation means for separating the gas and the waste liquid, the separated waste liquid is returned to the air blowing section, thereby repeatedly circulating the waste liquid, and
An apparatus for evaporating and concentrating photographic processing waste liquid, characterized in that the heating means for heating is provided so that the waste liquid and gas are formed around it. (2) The surface heat transfer amount of the heating means is 0.5 kcal/h.
r/cm^2 to 50 kcal/hr/cm^2, and the cross-sectional area of the space around the heating means through which the waste liquid and gas pass is in the range of 1 cm^2 to 300 cm^2,
2. The apparatus for evaporating and concentrating photographic processing waste liquid according to claim 1, wherein the flow velocity of the gas in the cross section is in the range of 0.5 m/sec to 50 m/sec.