JP2526978Y2 - Wastewater treatment equipment for dry cleaning machines - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wastewater treatment apparatus for evaporating wastewater from a dry cleaning machine together with a solvent contained in the wastewater.

[0002]

2. Description of the Related Art In a dry cleaning machine, water contained in clothes is mixed into a solvent during a washing process of clothes.
The mixed water is separated from the solvent by a water separator and then treated in a wastewater treatment device.

As such a waste water treatment apparatus, the evaporation tank waste water is introduced, a heating means and drainage evaporation air outlet of the air drainage is provided, Rutotomoni evaporated drainage increases the drainage temperature by heating A structure has been considered in which water is released as evaporative gas to the next step (for example, Japanese Utility Model Application No. 3-48561 proposed earlier by the present applicant).

[0004]

By the way, in the treatment structure using both the evaporation of the wastewater and the heating of the wastewater as described above, the efficiency of the evaporation increases when the temperature of the wastewater is increased. When the temperature rises above the boiling point, there is a problem that the concentration of the solvent contained in the evaporative gas increases significantly due to the azeotropic phenomenon.

[0005] Even if the evaporated gas having such a high solvent concentration is then passed through an activated carbon tank and the like to adsorb the solvent component, the solvent cannot be completely removed and is discharged to the outside. There is a problem that causes.

Accordingly, an object of the present invention is to solve the above-mentioned problem and to provide a processing apparatus capable of suppressing the concentration of a solvent in an evaporative gas to a low level in a structure in which evaporation of waste water and heating of waste water are used in combination. .

[0007]

Means for Solving the Problems] To solve the above problems, this invention concatenates introduction passage of the waste water separated from SOLVENTS the evaporation tank, blowing evaporation air drainage on top of the evaporation tank the outlet of the mouth and the evaporation gas is provided, the temperature detector at the bottom of the evaporator tank for detecting the heating means of the drainage, the drainage temperature
And the temperature of waste water is determined by the detection signal of the temperature detector.
The structure is provided with a control means for controlling the operation of the heating means so as to heat it to an azeotropic point or lower .

[0008]

In the above structure, the temperature of the waste water is detected,
The operation of the heating means is controlled so that the temperature of the waste water becomes lower than the azeotropic point. By controlling the heating temperature low in this way, an azeotropic phenomenon can be prevented, and the concentration of the solvent in the evaporated gas can be reduced.

Since the wastewater is controlled to be heated to a certain temperature range below the azeotropic point, the solvent does not boil near the azeotropic point.
Dry air is blown onto the drainage surface to evaporate the wastewater at a constant rate from the drainage surface, thereby evaporating the solvent concentration in the exhaust gas so that the solvent concentration is constantly at a constant low rate.

[0010]

FIG. 1 shows a wastewater treatment apparatus according to an embodiment. In the figure, reference numeral 1 denotes an evaporating tank, 2 denotes a water separator provided in a solvent recovery circuit of a dry cleaning machine, and a drain having a pump 5 between the water tank 3 and the evaporating tank 1 of the water separator 2. The introduction passage 4 is connected.

In the upper part of the evaporating tank 1, there are provided an air outlet 6 for introducing air for drainage evaporation and an outlet 7 for evaporative gas. Blower 9 is provided. A heater 11 connected to a steam supply pipe 10 is disposed below the air outlet 6 so as to heat the air blown out from the outlet 6 and supply the air into the evaporation tank 1.

A heating means 12 for heating the introduced waste water is provided below the evaporating tank 1. The heating means 12 comprises a heating plate 13 and a steam pipe 14 installed below the heating plate 13. A steam supply passage 15 connected to a steam supply source (not shown) has an electromagnetic on-off valve 16 in the steam pipe 14. Connected through.

A temperature detector 17 for detecting the temperature of the stored waste water is provided below the evaporating tank 1, and the temperature detector 17 is a controller 18 for controlling the opening and closing of the electromagnetic on-off valve 16. It is connected to the. The controller 18 can arbitrarily input the azeotropic point temperature from the outside according to the type of the solvent. The controller 18 compares the azeotropic point temperature with the waste water temperature detected by the temperature detector 17, and calculates the waste water temperature. When the temperature exceeds a suitable temperature equal to or lower than the azeotropic point, the electromagnetic on-off valve 16 is closed, and when the drainage temperature falls below the above-mentioned temperature by a certain value or more, the electromagnetic on-off valve 16 is opened.

Further, inside the evaporating tank 1, a horizontal separating plate 19 for dividing the inside of the evaporating tank into upper and lower parts is provided, and one end of the separating plate 19 faces below the discharge port 7. At the other end of the separator 19, a partition plate 20 extending downward in a direction perpendicular to the separator 19 is attached.

This embodiment has the above-described structure, and when performing drainage treatment, drainage is introduced into the evaporation tank 1 to a position where a small gap 21 is formed between the partition plate 20 and the liquid surface.

In this state, air is introduced from the outlet 6 and steam is supplied to the steam pipe 14 of the heating means 12. Blowing air, after being heated by the heater 11, blown out from the gap 21 between the partition plate 20 and the liquid level inside the separator 19, Ru evaporated drainage.

[0017] and evaporation of the waste water, by applying <br/> heat Ru good to the heating means 12, vapor is generated from the surface of the waste water, the vapor is led to the discharge port 7 by the separator 19, to the outside Released.

In the above operation, the temperature of the waste water rises,
When the temperature exceeds an appropriate temperature equal to or lower than the azeotropic point of water and the solvent, the controller 18 closes the electromagnetic on-off valve 16 by a signal from the temperature detector 17 and stops the supply of steam to the heating means 12. Conversely, when the temperature of the waste water falls below the azeotropic point by a certain value or more,
Controller 18 steam opens the solenoid valve 16 is introduced into the heating means 12, because this heating the waste water is restarted, drainage, heating and drainage at a constant temperature range of the azeotropic point vapor
Originating become Rukoto performed azeotropic phenomenon is prevented, it is possible to obtain a stable evaporation efficiency.

<Experimental Example> Using perchlorethylene (azeotropic point; 88 ° C.) as a solvent, water was separated from the solvent in a water separator 2, and wastewater having a solvent (perchlorethylene) concentration of 200 ppm or less was evaporated. It was introduced into tank 1. In this state, the drain temperature is set to 60
When the solvent was evaporated while being kept at ° C, the concentration of the solvent in the evaporated gas at the outlet 7 was in the range of 2 to 3 ppm.

On the other hand, when the same wastewater was evaporated at a wastewater temperature of 90 ° C., the concentration of the solvent in the evaporated gas increased to several hundred to several thousand ppm.

In the above embodiment, a solvent adsorption device such as an activated carbon adsorption tank is not installed in the evaporating tank 1, but an activated carbon adsorption tank is connected to the drainage introduction passage 4 or the discharge passage 8 so that the discharged solvent can be removed. The total amount may be suppressed.

The heater 11 for heating the evaporating air of the waste water may be provided inside the air outlet 6.

Furthermore, the heating means 12 for the waste water is not limited to the steam heating shown in the figure, but may employ another heating method such as electric heating.

[0024]

[Effect] As described above, the present invention detects the temperature of the waste water and controls the temperature of the waste water by heating to a constant value, so that the azeotropic phenomenon is prevented and the solvent concentration in the evaporative gas is reduced to a certain rate. And the wastewater can be treated with excellent environmental properties.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a wastewater treatment apparatus according to an embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Evaporation tank 4 Drainage introduction passage 6 Air outlet 7 Outlet 12 Heating means 16 Electromagnetic on-off valve 17 Temperature detector 18 Controller

Claims (1)

(57) [Scope of request for utility model registration] 1. A connecting the introduction passage of the waste water separated from SOLVENTS the evaporation tank, provided the outlet and outlet of vapor evaporation air drainage on top of the evaporation tank, the lower portion of the evaporation tank
Co is a heating means of the drainage, the <br/> a temperature detector for detecting the effluent temperature is provided, a drainage temperature by the detection signal of the temperature detector
A waste water treatment apparatus for a dry cleaning machine, comprising: a control means for controlling the operation of the heating means for the waste water so as to heat the water to a temperature below the boiling point .