JPS6372393A - Ultrapure water making apparatus - Google Patents

Abstract

PURPOSE:To miniaturize the title apparatus and to keep and enhance water quality, by providing a reciprocating piping port for the use point recirculation of transmitted water to the transmitted water or rear stage part of a reverse osmosis membrane. CONSTITUTION:The bypass line 11 reaching the suction side of a reverse osmosis membrane pressurizing pump 1 from the transmitting side of a reverse osmosis membrane 2 through a pressure control valve 10 is provided to the connection part of the reverse osmosis membrane 2 to a pure water pump 6 and a high purity water making machinery 7. A check valve 12 is arranged to the return line of use point recirculation piping so as to prevent the back-flow of recirculated treated water by the pressure of the reverse osmosis membrane on the transmitting side thereof. By this constitution, an inexpensive apparatus requiring no pure water pump is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an ultrapure water production apparatus used in semiconductor, electronic component industries, pharmaceutical and bio-related industries, and the like.

[Conventional technology]

The pharmaceutical industry, which manufactures medicines, and the electronics industry, which manufactures semiconductors, require water of extremely high purity. For example, the manufacturing of precision semiconductors such as integrated circuits (ICs) and large-scale integrated circuits (LSIs) The purity of washing water directly affects the yield of products, and increasing the purity of water has become an important issue.

A conventional ultrapure water production apparatus is constructed as shown in FIG. That is, raw water is supplied by high pressure pump 1.

The water is supplied to the reverse osmosis membrane 2 under pressure higher than the osmotic pressure to remove salts from the water. The permeated water desalinated by the reverse osmosis membrane 2 passes through a permeated water line 3 and is stored in a relay tank 4 having a free liquid level. On the other hand, the concentrated water produced by the reverse osmosis membrane 2 is drained through the concentration line 5. The permeated water in the relay tank 4, that is.

The treated water is finally treated by a high purity water component 7 comprising an ion exchange resin column, an ultraviolet sterilizer, an ultrafiltration membrane, etc. by a pure water pump 6, and is sent to a use point 8 to be used as water for cleaning. The ultrapure water (treated water) that is not used at use point 8 is constantly circulated through circulation line 9 to relay tank 4 - high purity water component 7 - use point 8 - relay tank 4 to prevent deterioration of water quality. It is configured like this.

An example of this type of device is Japanese Patent Application Laid-Open No. 61-61689.

[Problems to be solved by the invention] In the ultrapure water production device with the above configuration, the capacity of the relay tank increases in accordance with the processing capacity of the device due to the need to operate the device stably, and the device is generally large. Because of this, it is difficult to install it in a clean room, which requires expensive construction costs, and the equipment must be installed away from the point of use, resulting in long pipes for supplying treated water, which increases the cost of piping construction. Of course, there was a risk that the water quality would deteriorate during the piping. Furthermore, as air enters and exits from outside the tank in response to horizontal vertical fluctuations, the purity of the treated water in the relay tank decreases, and the accumulation of dead water in the relay tank can cause deterioration in water quality such as the growth of fungi. There is a risk of being exposed.

In addition, if there is a long distance between the equipment and the point of use, the water head loss in the piping will be large, so if water pressure at the point of use is required, install another pure water pump in front of the ultrafiltration membrane. It is necessary to pressurize the device by applying pressure, and there is a high possibility that the cost of the device will increase.

The purpose of the present invention is to reduce the size of the device and to maintain and improve water quality.

[Means for solving problems]

The above purpose is to pass the pressure control valve from the permeate side of the reverse osmosis membrane to
This is achieved by providing a line leading to the reverse osmosis membrane pressurizing pump suction side, and providing a reciprocating piping port for circulating the permeated water at the point of use on the permeated water side of the reverse osmosis membrane or at its subsequent stage.

[Effect]

In conventional technology, the amount of water permeated through the reverse osmosis membrane.

The difference in the amount of water used from the treated water at the point of use was compensated for by changing the amount of water stored in the relay tank 4. In the present invention, this difference is compensated for by changing the amount of water stored in the relay tank 4. By opening and closing the pressure regulating valve on the line leading to the suction side of the water, it is possible to respond to fluctuations in the amount of treated water used.

That is, when the amount of water used at the point of use decreases (increases), the amount of permeated water decreases (increases) in order to maintain the flow balance, so the pressure on the permeate side increases (decreases). g The amount of water returned from the valve to the raw water side increases (decreases). In this way.

The flow balance required for system operation can be maintained at all times.

〔Example〕

In FIG. 0, which describes an embodiment of the present invention with reference to FIG. 1, the same parts as in FIG. 4 are designated by the same reference numerals.

The main structure of the apparatus is the same as that described in FIG. 4. The present invention is illustrated in the connection portion between the reverse osmosis membrane 2, the pure water pump 6, and the high purity water purification equipment 7. That is, a bypass line 11 is provided from the reverse osmosis membrane permeation side to the suction side of the reverse osmosis membrane pressure pump 1 via the pressure regulating valve 10.

FIG. 2 shows a different embodiment from FIG. 1. In this embodiment, the position of the pure water pump 6 on the line is different from the above embodiments, and the pure water pump 6 is installed in front of the ultrafiltration membrane 7-d in the high purity water purification device 7.

In this case, the flow of water permeated through the reverse osmosis membrane in the high purity water purification device 7 to the pure water pump 6 is performed by pressure on the reverse osmosis membrane permeation side.

FIG. 3 shows still another embodiment. In this embodiment, the position of the joint water pump 6 on the line is different from the previous embodiment, and it is installed in the middle of the use point return pipe 9. In this case, since the pressure of the water permeated through the reverse osmosis membrane is used to send water to the point of use, there is an advantage that the pure water pump 6 only needs the power necessary to circulate the water through the circulation line.

In each embodiment, a check valve 12 is installed on the return line of the point-of-use circulation piping to prevent the circulating treated water from flowing backward due to pressure on the reverse osmosis membrane permeation side.

〔Effect of the invention〕

According to the present invention, an extremely compact ultrapure water production apparatus is provided, and the deterioration of water quality due to atmospheric pollution, which has been a problem in the prior art, is also prevented. Furthermore, there is no need for multiple pure water pumps to transport treated water to long distances, resulting in an inexpensive device.

[Brief explanation of the drawing]

FIG. 1 is a flow diagram for explaining one embodiment of the ultrapure water production apparatus of the present invention, FIG. 2 is a flow diagram for explaining another embodiment of the present invention, and FIG. 3 is a flow diagram for explaining an embodiment of the ultrapure water production apparatus of the present invention. FIG. 4 is a flowchart for explaining another embodiment, and FIG. 4 is a flowchart for explaining a conventional ultrapure water production apparatus. 1... High pressure pump, 2... Reverse osmosis membrane, 3... Permeated water line, 4... Relay tank, 5... Concentrated water line, 6... Pure water pump, 7... High purity water component equipment (7
-a, ion exchange resin tower, 7-b, ultraviolet sterilizer, 7-
c. Ion exchange resin tower, 7-d, ultrafiltration membrane) 8... Point of use, 9... Circulation line, 10... Pressure adjustment ゛1, -Bin・□

Claims (1)

[Scope of Claims] 1. In an ultrapure water production device comprising a reverse osmosis membrane, an ion exchange resin tower, an ultraviolet sterilizer, an ultrafiltration membrane, etc., a pressure regulating valve is installed from the permeated water side of the reverse osmosis membrane. It has a line that goes back to the suction side of the reverse osmosis membrane pressure pump,
An ultrapure water production device characterized in that a reciprocating piping port for circulation of the point of use of permeated water is provided on the permeated water side of a reverse osmosis membrane or at a subsequent stage. 2. The ultrapure water production apparatus according to item 1, characterized in that the ultrapure water circulation in the point-of-use circulation line is performed by a pressure pump provided upstream of the ultrafiltration membrane. Manufacturing equipment. 3. The ultrapure water production apparatus according to item 1, wherein the ultrapure water circulation in the point-of-use circulation line is carried out by a pressure pump provided on the return side of the circulation line. . 4. The ultrapure water production apparatus according to item 1, characterized in that a check valve is provided in the middle of the use point circulation pipe and return pipe.