JPH11343976A - Oil separating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively separate drain into oil and water by providing a container storing drain generated when compressed air is cooled, performing pressure reduction for the inside of this container by a vacuum pump and providing a valve controlling drain amount flowing into the container, in an oil-feeding type air compressor. SOLUTION: Air compressed by an oil-feeding type air compressor 7 contains oil content, and when this compressed air is cooled by an air cooling device 8, moisture content is condensed. Drain generated in the air cooling device 8 and oil content contained in compressed air become emulsion states and flows in an oily water separating vacuum chamber 2 via a trap 9 and an oily water feed valve 3. When fixed quantity of drain is accumulated in the vacuum chamber 2, the oily water feed valve 3 is closed, drain is heated by a heating device 6 and a vacuum pump 1 is operated. As a result, moisture content in drain within the vacuum chamber 2 is boiled, is discharged to the atmosphere through the vacuum pump 1, only oil content is left within the vacuum chamber 2 and this oil content is subsequently discharged via a drain oil valve 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can be used in the field of oil supply type air compressors in which drain condensed during cooling of compressed air is separated into oil and water and the oil is collected in an oil drain tank.
Further, the oil-water separation device of the present invention can be used not only for the drain of an oil supply type air compression device but also for a wastewater treatment device for general industry.

[0002]

2. Description of the Related Art The main method of oil-water separation in the prior art, for example, (JP-B-7-26615, JP-B-4-33430) is as follows. The drain is introduced into the drain separation tank from an air line device such as an aftercooler, an air tank, a dryer and a line filter where the compressed air is cooled to generate a drain. . The floating oil collected at the top is collected from the oil drain valve. The lower drain is introduced into the filter element tank,
Oil is filtered by the element.

[0003] The water that has passed through the filter element is discharged to the drain as it is because the oil has been removed therefrom. The function and performance of oil-water separation are maintained by periodically replacing the filter element that has adsorbed oil with a new filter element.

[0004] The exchanged filter element contains a large amount of oil and cannot be disposed of as general waste, but must be treated as industrial waste by requesting a specialized trader, resulting in high operating costs.

[0005]

As the number of establishments acquiring environmental ISO increases, wastewater treatment is an important issue, and among them, oil-water separation of wastewater is the most common issue. In the oil-water mixture, the drain of the oil-supplying compressor is generally emulsified, so it cannot be completely separated only by the specific gravity difference of oil and water. A method of adsorbing oil to the element is a general method in the prior art. This method has the following problems.

[0006] 1. In order to maintain the function and performance of the oil / water separation, it is necessary to periodically replace the element, which is expensive.

[0007] 2. Replaced elements must be treated as industrial waste by a specialist.

[0008] 3. It is necessary to check periodically whether the oil remaining in the water separated through the filter element is within the allowable value permitted by environmental regulations, which is not reliable.

4. In order to maintain the performance of adsorbing oil to the filter element, the speed of drainage must be reduced, and it is difficult to reduce the size of the device.

[0010] The present invention achieves the following objects.

1. Separate oil and water without using a filter element.

2. The separated water is returned to the atmosphere instead of being drained, thereby making it unnecessary to check the oil concentration.

3. Reduce the size of the oil-water separator.

4. Maintenance-free operation costs are reduced.

[0015]

Means for Solving the Problems Water is 1 at atmospheric pressure.
Boils and evaporates at 00 ° C, but the oil does not boil. When the pressure is reduced, the boiling point of water drops to 100 ° C. or lower, but the boiling point of oil is as high as about 300 ° C., and the water boils first and evaporates. By utilizing the difference in physical properties, the drain in the emulsion state is separated into oil and moisture, and the moisture is reduced to the atmosphere in a vapor state.

After the water evaporation, the remaining oil is reused or treated as waste oil. Therefore, no filter element is required, and maintenance-free operation that does not require periodic maintenance can be achieved. Further, the amount of boiling evaporation of water is determined by the degree of vacuum, and it is not necessary to linearly increase the element size with respect to the processing amount unlike the filter element method, and the apparatus can be downsized.

[0017]

FIG. 1 shows the flow of an embodiment of the present invention. It comprises a vacuum pump 1, an oil / water separation vacuum chamber 2, an oil / water inlet valve 3, an oil drain valve 4, an equalizing valve 5, and a heater 6,
An oil supply type compressor 7, an air cooler 8, and a drain trap 9 are shown as a system for generating an oil-water mixture.

The air compressed by the refueling compressor 7 contains oil. When the compressed air is cooled by the air cooler 8, the amount exceeding the saturated steam pressure is condensed as drain. The drain generated in the air cooler 8 and the oil contained in the compressed air are mixed, and become an emulsion state to flow into the oil / water separation vacuum chamber 2 from the drain trap 9 via the oil / water supply valve 3.

An oil / water separation vacuum chamber 2 has a certain amount of drain.
, The oil / water supply valve 3 is closed, heating by the heater 6 and operation of the vacuum pump 1 are started, and the inside of the oil / water vacuum chamber is heated to a vacuum state. As a result, the water in the drain boils and is reduced to the atmosphere through the vacuum pump 1, leaving only the oil in the oil-water separation vacuum chamber. At this stage, the vacuum pump 1 is stopped, the heater 6 is turned off, the pressure equalizing valve 5 and the oil drain valve 4 are opened, and the oil is discharged.

Thereafter, the oil drain valve 4 and the pressure equalizing valve 5 are closed,
By opening the oil / water inlet valve 3 and repeating the above operation,
Oil-water separation is performed continuously.

FIG. 2 shows an embodiment utilizing the exhaust heat of an air compressor as a heater. The configuration and operation from 1 to 5 are the same as those in the embodiment of FIG. The unique configuration of the present embodiment resides in that a heat exchanger using the exhaust heat of an air-cooled air compressor is used for the heater of the present invention. Air compressor 7
The compressed air enters the oil separator 8 and the oil is primarily separated. The primarily separated compressed air enters the filter 10 through the pipe 9 and the oil is secondarily separated. The compressed air after the secondary separation is guided to an air cooler 12 through a pipe 11 and cooled.

By this cooling, the water in the compressed air is condensed as a drain, and the oil in the compressed air is mixed into the drain. The drain containing the oil is drained to the drain trap 1
It is led to the heat exchanger 6 through 3 and heated. The heated drain is supplied to the oil / water separation vacuum chamber 2 through the oil / water inlet valve 3.
to go into.

On the other hand, the oil that has absorbed the heat of compression by the air compressor 7 is primarily separated by the oil separator 8 and is cooled by the oil cooler 15 through the pipe 14. The cooling air heated by the oil cooler is exhausted by the cooling fan 16, and the exhaust air is passed through the heat exchanger 6, and the exhaust heat is added to the drain to raise the temperature of the drain.

[0024]

(1) The oil has a boiling point of 280 to 30 in a vacuum state.
Since the boiling point of water is 100 ° C. or lower with respect to 0 ° C., drainage in an emulsion state can be separated into oil and water by reducing the pressure.

(2) The separated water is returned to the atmosphere and does not pollute the environment.

(3) The separated oil can be reused.

(4) No filter element is required for separation and no industrial waste is generated.

(5) Since there is no dimensional restriction in design unlike the filter element, the size can be reduced and it can be built in the air compressor unit.

(6) It can be commercialized from a small capacity to a large capacity.

(7) The exhaust heat of the air compressor can be used as a heat source for heating.

(8) Periodic maintenance such as the filter element method is not required, and the performance does not decrease over time, so that the reliability is high.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an oil-water separation device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram showing a device configuration and a flow using exhaust heat of the air compressor of FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Vacuum pump, 2 ... Oil-water separation vacuum chamber, 3 ... Oil-water feed valve, 4 ... Oil drain valve, 5 ... Equalization valve, 6 ... Heater.

Claims (2)

[Claims] In a refueling type air compressor, a container for storing drain generated when compressed air is cooled, a vacuum pump for reducing the pressure in the container, and a valve for controlling the amount of drain flowing into the container. An oil-water separation device comprising: 2. A container for storing drain generated when compressed air is cooled, a vacuum pump for reducing the pressure in the container, a valve for controlling the amount of drain flowing into the container, and a heater for heating the container. Alternatively, an oil-water separation device comprising a heating device using a cooler exhaust of an air-cooled air compressor.