JPS63141601A - Method and device for treating waste liquid - Google Patents

Abstract

PURPOSE:To prevent the generation of rancidity and harmful gases by forming the lower part of an evaporator with a small-bore part to promote the convection of the liq. by heating, and controlling the liq. level while avoiding the long period retention of the liq. in the high-temp. part. CONSTITUTION:The evaporator 1 closed at the upper part is formed with the small-bore barrel part 2, and a sludge discharge part is provided under the part 2 through a valve 3. The small-bore barrel part 2 is fitted with a heating mechanism 7. A steam discharge pipe 8 is connected to the upper end of the evaporator 1, a pipe 10 with the rear end dipping in a waste liq. tank 9 is connected to the upper part of the evaporator, and the waste liq. preheated by a heat exchanger 11 is supplied to the evaporator 1. A liq. level controller 14c is provided to the evaporator 1, a liq. pump 13 is controlled by the level controller when the liq. level rises to the position of the controller, and the level is kept between level controller 14a and 14b by the controllers.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a method for treating waste liquid, such as waste liquid from photographic development, in which it is necessary to avoid exposing substances contained in the waste liquid to high temperatures for a long period of time. It is related to the device.

(Prior art and its problems) Methods such as flash drying and drum drying are used as waste liquid treatment methods depending on the nature of the waste liquid.

However, depending on the type of waste liquid, there are some that tend to generate bad odors and harmful gases when the products containing the waste liquid are exposed to high temperatures for a long period of time.

Therefore, the purpose of this invention is to prevent the substances contained in the waste liquid from being exposed to high temperatures for a long time, and to quickly accumulate the sludge generated in the heating section in a low temperature region, thereby preventing the generation of bad odors, harmful gases, and release into the atmosphere. An object of the present invention is to provide a waste liquid treatment method that minimizes diffusion, and an apparatus therefor.

[Means for solving problems]

In order to solve the above problems, one of the present inventions is to preheat the waste liquid and supply it to the closed evaporator, and heat it in the lower small-diameter cylindrical part of the evaporator to intensify the convection of the liquid in the heating part. The concentrated liquid mixed sludge generated in the small diameter cylinder is received in the lower container, and the steam generated in the evaporator is used for preheating the supplied waste liquid, then cooled and condensed and disposed of as water. This is a waste liquid treatment method that detects the liquid level and adjusts the liquid level within a predetermined level range to constantly maintain the waste liquid in the evaporator within a required concentration range.

In order to solve the above problems, another aspect of the present invention is that the upper part is sealed and the lower part is a small-diameter cylindrical part equipped with a heating mechanism, and the lower part of the small-diameter cylindrical part is used as a sludge discharge part with a valve interposed therebetween. It consists of an evaporator, a steam exhaust vibrator connected to the upper end of the evaporator, and a raw solution supply pipe that connects the upper part of the evaporator and the waste liquid stock tank. A lift pump is interposed near the rear end of the raw solution supply pipe, the evaporator side is passed through the heat exchanger, and upper and lower limits of a predetermined liquid level are installed above the evaporator. The waste liquid processing device is provided with a detection mechanism, and the lower detection mechanism is used to operate the liquid pump of the raw liquid supply pipe, and the upper limit detection mechanism is used to stop the operation of the liquid pump.

〔Example〕

In the figure, 1 is an evaporator whose upper part is sealed, and the lower side is a small-diameter cylinder part 2, and the lower part is a sludge discharge part 4 with a pulp 3 interposed therebetween. In the figure, a sludge receiver 6 is connected to a sludge discharge part 4 and a closed camp 6 is connected to a container 5.

A heating mechanism 7 consisting of an electric heater is attached to the small diameter cylindrical portion 2 of the one-shot can 1.

A steam exhaust pipe 8 is connected to the upper end of the evaporator 1.
A stock solution supply pipe 10 whose rear end is inserted into a waste solution stock tank 9 is connected to the upper part of the evaporator.

A heat exchanger 11 and a condenser 12 are interposed in that order from the evaporator 1 side in the steam exhaust vibe 8, and a raw solution supply pipe 10
A liquid lift pump 13 is interposed near the rear end, and the evaporator side is passed through a heat exchanger.

The evaporator 1 is equipped with level controllers 14a and 14b for detecting the liquid level, which are composed of sensors and the like, at a required distance from each other vertically. Interposed liquid pump 1
3, and when the liquid level reaches the lower level controller 14, the lift pump is driven to supply the waste liquid concentrate, and at the end of the process, the lift pump 13 is stopped and the liquid level reaches the small diameter cylinder. When the level controller 14C at the upper end of the section 2 is lowered, the operation of the heating mechanism 7 is also stopped.

The condensed water receiver at the rear end of the steam exhaust vibrator 8 is inserted into the sealing plug 16 of the container 15, and the activated carbon filter 17 is inserted into the sealing plug 16.
A pipe 18 is connected to the pipe.

19 is a sludge receiver whose rear end is located in the upper part of the container 5 and whose tip is connected to the upper side of the evaporator 1; the sludge receiver is a bypass pipe that returns the supernatant liquid in the container 5 to the evaporator 1; is the pump.

Reference numeral 21 indicates a refrigerator that circulates cooling water through a spiral cooling water pipe 22 within the condenser 12.

To explain the operation of this waste liquid treatment device, the liquid waste liquid is put into the liquid liquid tank 9 (a 20-liter plastic container), and the rear end of the liquid liquid supply pipe 10 is deeply inserted into this tank, and the liquid pump 13 is driven, and at the same time it is evaporated. The heating mechanism 7 of the can 1 is also activated.

When the liquid level in the evaporator 1 reaches the level controller 14C, the liquid pump 13 is switched to control by the level controller, and when the liquid level in the evaporator 1 reaches the level controller 143, the liquid pump 13 stops. However, when the liquid level falls to the level controller 14b, the pump 13 is driven, and the liquid level in the evaporator 1 is between the level controllers 14a and 14b.

When the raw liquid in the evaporator 1 is heated and steam is generated, the sludge generated and settled in the small diameter cylinder part 2 is received in the sludge receiver together with the concentrated liquid, and the steam from the steam discharge pipe 8 from the evaporator 1 is collected. is the raw solution supply pipe 1 in the heat exchanger 11
The load on the heating mechanism 7 in the evaporator 1 is reduced by heating (preheating) the stock solution from 0.

The steam in the steam exhaust pipe 8 is transferred from the heat exchanger 11 to the condenser 12
This water condenses into water, and the condensed water receiver is the container 15.
At the same time, the air in this container passes through an activated carbon filter 17 and is released into the atmosphere without odor.

When finishing the waste liquid treatment, the operation of the heating mechanism 7 is stopped when the liquid level in the evaporator 1 has fallen to the level controller 14C, and then the pump 20 is activated and the sludge receiver transfers the upper liquid in the container 5 to the evaporator 1. When necessary, the sludge receiver injects a chemical solution such as a neutralizing agent into the container 5, and the sludge receiver settles the sludge in the container and processes it into a cake.

21 is a tank for a chemical liquid such as a neutralizing agent, and 22 is a pipe for pouring the chemical liquid into a sludge container.

The pump 20 for the bypass pipe 19 of the evaporator 1 is used to generate the flow of liquid necessary to cause the settled sludge in the small diameter cylinder part 2 to flow down together with the liquid. The sludge receiver is used to return the upper liquid in the container at the end of the treatment, and this pump 20 pumps up the liquid so that the convection of the liquid in the evaporator is as minimal as possible. It is assumed that this has been set.

In the figure, reference numeral 23 denotes a bellows-type valve which is formed on the cap 24 of the waste liquid stock tank 9 and has the ability to always close in the closed direction.The camp 24 is made airtight, and outside air flows in through this valve portion during liquid pumping.

Reference numeral 25 indicates a refrigerator that supplies cooling water to the cooling water circulation pipe 26 in the cooler 12, and 27 indicates a liquid level gauge for making it possible to visually check the liquid level in the evaporator 1.

〔effect〕

The waste liquid treatment method and apparatus of the present invention have the following effects.

+11 During the process of concentrating and drying the waste liquid, the waste liquid is not exposed to high temperatures for a long period of time, so the generation of bad odors and harmful gases caused by long-term exposure to high temperatures is significantly reduced.

(2) Since the waste liquid is heated in the lower small diameter part of the evaporator, convection of the liquid in the heating part is strong, and therefore, long-term retention in the high temperature part can be avoided.

(3) Since the sludge generated in the waste liquid heating section quickly settles and accumulates in the lower low temperature region, the generation of foul odors and harmful gases is extremely reduced.

(4) Level control of the upper and lower limits of the evaporator to prevent dry firing,
Continuous concentration is possible while maintaining the minimum liquid volume (concentration) that prevents the waste liquid from being exposed to high temperatures for a long time.

(5) The device can be made small and energy saving can be satisfied.

[Brief explanation of the drawing]

The drawing is a flowchart diagram illustrating an embodiment of the method and apparatus of the present invention. 1...Evaporator, 2...Small diameter cylinder part, 3.
... Pulp, 4 ... Sludge discharge section, 7
... Heating mechanism, 8 ... Steam discharge pipe, 10 ... Raw solution supply pipe, 11 ...
Heat exchanger, 12... Condenser, 13...
Liquid pump, 14a, 14b...level controller.

Claims (2)

[Claims] (1) The waste liquid is preheated and supplied to the closed evaporator, and heated in the lower small-diameter cylinder of the evaporator to intensify the convection of the liquid in the heating part, and the concentrated liquid mixed sludge generated in the small-diameter cylinder is transferred to the lower part of the evaporator. The steam generated in the evaporator is used to preheat the supplied waste liquid, and then it is cooled and condensed and disposed of as water.The amount of waste liquid in the evaporator is detected and the liquid level is adjusted to a predetermined level. A waste liquid treatment method characterized by adjusting the concentration of the waste liquid in the evaporator to a desired concentration range at all times. (2) an evaporator whose upper part is sealed and a heating mechanism is attached to the lower side of the evaporator; the lower part of the small-diameter cylindrical part is a sludge discharge section with a valve; and a steam discharge pipe connected to the upper end of the evaporator; and a raw solution supply pipe that connects the upper part of the evaporator and the waste liquid stock tank.The steam discharge pipe has a heat exchanger and a condenser interposed in that order from the evaporator side, and the raw solution supply pipe has a pipe near the rear end. A pump is interposed between the evaporator side and the evaporator side passes through the heat exchanger, and a mechanism for detecting the upper and lower limits of a predetermined liquid level is attached to the upper side of the evaporator. A waste liquid treatment device, characterized in that the upper limit detection mechanism for operating the liquid pump is used for stopping the operation of the liquid pump.