KR101019032B1 - Treatment apparatus and method for wafer waste water - Google Patents

Abstract

PURPOSE: A processing apparatus for wafer fabrication wastewater, and a processing method thereof are provided to recycle the fabrication wastewater generated from cutting a wafer. CONSTITUTION: A processing apparatus for wafer fabrication wastewater comprises the following: a wastewater storage tank(10) for storing waste water; a filter unit(20) filtering the wastewater using a hollow fiber separation film; a filtrate storage tank(30) storing filtrate obtained by passing the wastewater through the hollow fiber separation film; and an air compressor for washing the filter unit.

Description

Treatment apparatus and method for wafer processing wastewater {treatment apparatus and method for wafer waste water}

The present invention is an apparatus for separating the processing wastewater into a solid material and a liquid material using a hollow fiber separator to recycle the processing wastewater generated during wafer cutting, and to clean and process the solid material accumulated on the surface of the hollow fiber membrane And to a method.

Recently, the demand for silicon wafers is increasing rapidly due to the rapid development of ICT and semiconductor industry, the depletion of petroleum energy, and the use of solar energy for global warming.

In general, a silicon wafer is manufactured by cutting a wire saw while continuously supplying a cutting liquid mixed with cutting oil and an abrasive in a silicon ingot to a cutting surface.

Cutting oils commonly used in wire saws are composed of petroleum-based paraffin oil as a main component and a mixture of a surfactant, a dispersant, a thickener, and the like, and the cutting oil has an even abrasive such as silicon carbide, aluminum oxide, and silicon dioxide. It is dispersed and constitutes cutting fluid.

In addition, in order to easily clean the wafers with the cutting liquid after the cutting process, a cutting liquid in which an abrasive is mixed with a water-soluble polyethylene glycol or polypropylene glycol may be used instead of the paraffin oil.

The cutting oil uniformly enters the abrasive between the wire and the ingot, cools the frictional heat generated during the cutting process, and plays a role of lubrication.

In the cutting process, a cutting powder is inevitably generated, and the cutting powder is mixed with the cutting liquid and deposited in the cutting liquid container or supplied to the cutting surface with abrasive to warp or warp the cutting surface of the wafer. Etc. There arises a problem of lowering the quality of the wafer.

Therefore, the cutting fluid whose performance has been degraded after a certain period of time is disposed of, which increases the production cost of the wafer. Since the waste cutting fluid contains cutting powder and cutting oil, air pollution may occur when incineration is performed. In this case, serious soil pollution is a concern.

In addition, the cleaning waste water is generated when the wafer is cleaned, and the cleaning waste water contains the cutting liquid used in the cutting process.

Accordingly, researches on the recycling of wafer processing wastewater, such as waste cutting fluid and cleaning wastewater, have been actively conducted. Recently, a method for recovering and reusing abrasives, cutting powder, and cutting oil contained in wafer processing wastewater has been proposed.

As part of such a scheme, there is a treatment method using a separator, which is widely used in terms of securing stable water quality, economical efficiency, and clean technology.

The separation membrane is a device for separating substances according to the size of the molecule or the repulsive force between the molecule and the separation membrane, etc. The type of separation membrane includes reverse osmosis membrane, nanofiltration membrane, ultrafiltration membrane, microfiltration membrane, ion exchange membrane, gas separation membrane, pervaporation membrane and the like.

There are various types of membrane modules, such as flat, tubular, spiral wound, and hollow fiber, among which hollow fiber membrane modules have a hollow fiber membrane having a surface layer of the membrane inside or outside a thin tube that can support the membrane itself. It is a bunch form.

The filtration principle of the hollow fiber membrane module is such that particles larger than the pores of the membrane are trapped in the membrane and particles smaller than the pores of the membrane are separated from each other by passing through the membrane while the liquid coming into or out of the membrane is pressurized. It is.

If the filtration is continued, particulate or dissolved substances adhere to the membrane surface or the pore surface, thereby blocking the pores of the membrane and gradually decreasing the flow rate of the filtrate passing through the membrane.

In order to prevent such membrane contamination, the membrane filtration performance should be restored by periodically washing the surface of the membrane during the membrane filtration operation or by backwashing the washing water through the membrane pores in the reverse direction of the filtration direction.

The washing water for backwashing depends on the type of wastewater to be filtered, but in general, a solution obtained by mixing acid, alkali, inorganic and organic detergents with filtered permeate or permeate is used. Backwash is performed by pressurizing the pump with a pump or the like.

However, the conventional backwashing method removes solids on the surface of the separator by flowing the wash water in the opposite direction to the membrane filtration direction. As the operation and backwashing are repeated after the initial operation, the phenomenon of solid matter gradually sticking to the surface of the separator is observed. And the filtration efficiency gradually decreases even after backwashing.

Therefore, in order to maintain the filtration efficiency above a certain level, the backwashing time is increased or the backwashing interval is shortened, and afterwards, the separation time of the membrane must be removed to remove the solid material.

Therefore, in order to continuously operate such a hollow fiber membrane for a long time, development of a wastewater treatment apparatus and treatment method capable of preventing the backwashing efficiency from deteriorating over time is required.

The problem to be solved by the present invention is to separate the cutting oil, abrasives, cutting powder, etc. contained in the waste water generated in the wafer cutting process with a hollow fiber membrane to recycle, and to efficiently collect the solid material accumulated in the hollow fiber membrane in the separation process It is an object of the present invention to provide an apparatus and a method which can be washed and treated.

In order to achieve the above object, the present invention, wastewater storage tank for storing the wastewater (10); A filter unit 20 for receiving the wastewater from the wastewater storage tank 10 and filtering using a built-in hollow fiber membrane; Permeate storage tank 30 for storing the filtered permeate while the waste water of the filter unit 20 permeate the hollow fiber membrane; And an air compressor 40 for cleaning the filter unit 20.

At this time, the filter unit 20, the tubular body 21 having an internal space; A plurality of hollow fiber separation membranes 22 installed in the inner space of the body 21 to allow particulate matter of a small size in the wastewater to permeate; An inlet nozzle 23 installed at a lower end of the body 21 to introduce wastewater from the wastewater storage tank 10; An outflow nozzle 24 installed at an upper end of the body 21 to allow wastewater that has not passed through the separation membrane 22 to flow out; A permeate nozzle (25) installed on the outer circumferential surface of the body (21) to discharge the permeate from the wastewater through the separation membrane (22); And it is preferable to include a reverse nozzle (26) for washing the separation membrane 22 is installed below the outer peripheral surface of the body (21).

In addition, one end of the wastewater storage tank 10 is connected to the inlet nozzle 23, and the other end of the wastewater supply pipe L1 having the wastewater transfer pump 11 interposed therebetween is connected to the filter unit 20. Possibly connected; The wastewater inlet valve V1 is interposed between the inlet nozzle 23 and the transfer pump 11 of the wastewater supply pipe L1, and the inlet nozzle 23 and the wastewater inlet valve V1 of the wastewater supply pipe L1 are interposed. One end flows to the outside and the other end of the drain pipe L6 with the drain valve V6 interposed therebetween is connected; The outflow nozzle 24 of the filter unit 20 has one end connected to the wastewater storage tank 10 and the other end of the wastewater return pipe L2 having the wastewater discharge valve V2 interposed therebetween so that the wastewater storage tank ( 10) circulating in circulation; One end of the permeate fluid nozzle 25 of the filter unit 20 is connected to the permeate fluid storage tank 30, and the other end of the permeate fluid transfer pipe L3 having the permeate fluid valve V3 interposed therebetween is connected to the above. It is connected to the permeate storage tank 30 and circulating; The backwash nozzle 26 of the filter unit 20 has one end connected to the permeate storage tank 30 and the other end of the backwash tube L4 having the backwash pump 31 interposed therebetween so that the permeate storage tank ( 30), and a backwash valve (V4) is interposed between the backwash nozzle (26) and the backwash pump (31) of the backwash pipe (L4); One end is connected between the outflow nozzle 24 of the wastewater return pipe L2 and the wastewater outlet valve V2, and the other end thereof is connected between the backwash valve V4 and the backwash pump 31 of the backwashing pipe L4 to each other. A fine pipe (L7) connected to the circulation and interposed with a fine valve (V7); One end is connected between the outflow nozzle 24 and the wastewater outlet valve V2 of the wastewater return pipe L2, and the other end is connected to the air compressor 40 so as to be circulated so that the air supply valve V8 is on the way. More preferably, the interposed air supply pipe L8 is provided.

Further, one end is connected between the backwash pump 31 of the backwashing pipe L4 and the backwash valve V4, and the other end thereof is the permeate fluid 25 and the permeate valve V3 of the permeate conveying pipe L3. It is even more preferable that a branch pipe L5, which is connected between each other so as to be able to flow to each other, and which has a branch valve V5 interposed therebetween.

In addition, it is more preferable that one end is connected to the permeate storage tank 30 and the other end is connected to the washing tube L7 upstream of the washing valve V7 and a facility in which a pump is interposed is added.

In addition, the present invention is a wastewater storage tank for storing wastewater, a filter unit for receiving the wastewater of the wastewater storage tank and filtering using a built-in hollow fiber membrane, the wastewater supplied to the filter unit is filtered through the hollow fiber membrane A method for operating a wafer processing wastewater treatment apparatus including a permeate storage tank for storing a liquid and an air compressor for cleaning the filter unit, the method comprising: blocking wastewater supply of the filter unit and discharging the wastewater inside the filter unit to the outside; step; And supplying the permeate of the permeate storage tank in the reverse direction of the flow direction through which the waste water penetrates to the hollow fiber-type separation membrane of the filter section, and simultaneously supplying the pressurized air from the air compressor to the hollow fiber type separation membrane in the reverse direction of the wastewater flow direction. While discharging to the outside while providing a wafer processing wastewater treatment method comprising a.

In addition, the present invention is a wastewater storage tank for storing wastewater, a filter unit for receiving the wastewater of the wastewater storage tank and filtering using a built-in hollow fiber membrane, the wastewater supplied to the filter unit is filtered through the hollow fiber membrane A method for operating a wafer processing wastewater treatment apparatus including a permeate storage tank for storing a liquid and an air compressor for cleaning the filter unit, the method comprising: blocking wastewater supply of the filter unit and discharging the wastewater inside the filter unit to the outside; step; Discharging the air pressurized by the air compressor to the hollow fiber membrane of the filter unit in the reverse direction of the waste water flow direction and discharged to the outside; Shutting off the air supply and discharging the permeate of the permeate reservoir to the hollow fiber membrane of the filter part in a reverse direction of the wastewater flow direction and then discharging the permeate to the outside; Supplying the permeate solution and discharging the permeate of the permeate reservoir to the hollow fiber membrane of the filter part in a reverse direction in a flow direction through which the waste water permeates; do.

In the wafer processing wastewater treatment apparatus and method according to the present invention, since the solid material accumulated in the separator is simultaneously washed in the reverse direction of the permeate flow direction and the reverse direction of the wastewater flow direction, the washing efficiency is increased.

In addition, the filtration efficiency of the membrane is increased because the solid material that may remain in the liquid flow stagnant space of the filter portion in which the membrane is embedded is removed together with the membrane washing.

In addition, the present invention is to separate the solid and liquid materials contained in the wafer processing waste water from each other, cutting oil or oil components containing oil components such as abrasives and paraffin or glycol as a solid material, surfactants, dispersants, thickeners, etc. The cleaning solution can be recycled, contributing to the reduction of wafer manufacturing cost.

1 is a conceptual diagram of a wafer processing wastewater treatment apparatus according to an embodiment of the present invention.
FIG. 2 is a view showing the flow rate of the permeate while alternately performing a filtration step and a backwashing step for wastewater containing a glycol component.
FIG. 3 is a view showing the flow rate of the permeate while alternating the filtration step and the backwashing step for the wastewater containing no glycol component.
4 is a view showing the flow rate of the permeate while simultaneously performing backwashing and air washing of the wastewater containing the glycol component.
FIG. 5 is a view showing the flow rate of the permeate while simultaneously performing backwashing and air washing for the wastewater containing no glycol component.
FIG. 6 is a view showing the flow rate of the permeate while sequentially washing air, washing and backwashing the wastewater containing the glycol component.
FIG. 7 is a view showing the flow rate of the permeate while sequentially washing air, washing and backwashing the wastewater containing no glycol component.

Hereinafter, an embodiment according to the present invention will be described in detail with reference to FIG. 1.

However, the following examples are only for illustrating the present invention, and the present invention is not limited by the following examples, and may be changed to other embodiments equivalent to substitutions and equivalents without departing from the technical spirit of the present invention. Will be apparent to those of ordinary skill in the art.

In Fig. 1, the wafer processing wastewater treatment apparatus of this embodiment is indicated by the reference numeral 100.

The membrane device 100 is a waste water storage tank 10 for storing waste water, the filter unit 20 for receiving the waste water of the waste water storage tank 10 and filtering using a built-in hollow fiber membrane, the filter unit 20 Permeate storage tank 30 for storing the filtered permeate while the wastewater of the hollow fiber membrane; And an air compressor 40 for washing the filter unit 20.

The filter unit 20 is a tubular body 21 having an inner space, a plurality of hollow fiber-type separator 22 is installed in the inner space of the body 21 to permeate the particles of small size in the waste water, the body Inlet nozzle 23 is installed at the lower end of the 21 to the waste water of the wastewater storage tank 10, the discharge nozzle is installed in the upper end of the body 21 to the waste water that has not passed through the separation membrane 22 (24), the permeate nozzle 25 is installed on the outer peripheral surface of the body 21 is discharged through the separation membrane 22 to discharge the filtered permeate and the lower peripheral surface of the body 21 and It includes a backwash nozzle 26 for washing the separation membrane (22).

delete

In addition, the filter unit 20 may be installed in a vertical direction so that the waste water is drawn out from the bottom to flow out to the top, may be installed in a horizontal direction so that the waste water is drawn in from one side to flow out to the other side.

The wastewater storage tank 10 has one end connected to the inlet nozzle 23 and the other end of the wastewater supply pipe L1 having the wastewater transfer pump 11 interposed therebetween to be circulated with the filter unit 20. It is connected.

The wastewater inlet valve V1 is interposed between the inlet nozzle 23 and the transfer pump 11 of the wastewater supply pipe L1, and the inlet nozzle 23 and the wastewater inlet valve V1 of the wastewater supply pipe L1 are interposed. The other end of the drain pipe L6 with one end flowing through the outside and the drain valve V6 interposed therebetween is connected.

The outflow nozzle 24 of the filter unit 20 has one end connected to the wastewater storage tank 10 and the other end of the wastewater return pipe L2 having the wastewater discharge valve V2 interposed therebetween so that the wastewater storage tank ( 10) is connected to the distribution.

One end of the permeate fluid nozzle 25 of the filter unit 20 is connected to the permeate fluid storage tank 30, and the other end of the permeate fluid transfer pipe L3 having the permeate fluid valve V3 interposed therebetween is connected to the above. It is connected to the permeate storage tank 30 so as to be circulated.

The backwash nozzle 26 of the filter unit 20 has one end connected to the permeate storage tank 30 and the other end of the backwash tube L4 having the backwash pump 31 interposed therebetween so that the permeate storage tank ( 30) is circulated in circulation.

A backwash valve V4 is interposed between the backwash nozzle 26 and the backwash pump 31 of the backwashing pipe L4, and one end thereof is between the backwash pump 31 and the backwash valve V4 of the backwashing pipe L4. A branch pipe (L5) connected to the other end is connected between the permeate fluid nozzle (25) and the permeate valve (V3) of the permeate transfer pipe (L3) so as to be circulated with each other, and the branch valve (V5) is interposed. Is installed.

One end is connected between the outflow nozzle 24 of the wastewater return pipe L2 and the wastewater outlet valve V2, and the other end thereof is connected between the backwash valve V4 and the backwash pump 31 of the backwashing pipe L4 to each other. A tubular pipe L7 is connected to the tank and provided with a tubular valve V7 interposed therebetween.

One end is connected between the outflow nozzle 24 and the wastewater outlet valve V2 of the wastewater return pipe L2, and the other end is connected to the air compressor 40 so as to be circulated so that the air supply valve V8 is on the way. An interposed air supply pipe L8 is installed.

Although not shown in FIG. 1, one additional pump may be installed separately from the backwash pump 31 as a pump for supplying permeate to the cleansing pipe L7.

That is, one end is connected to the permeate storage tank 30, the other end is connected between the backwash pump 31 and the clean valve V7 of the clean pipe L7, and the pump is interposed to add the facility. In case of failure of the pump 31, the added pump can be operated and the backwash pump 31 can be repaired, which is advantageous for continuous operation.

The separator device of the present embodiment configured as described above is operated as follows.

1) Filtration Process

Waste water inlet valve (V1), waste water outlet valve (V2) and permeate valve (V3) are open, and backwash valve (V4), branch valve (V5), drain valve (V6), washing valve (V7) and In the state in which the air supply valve V8 is closed, the wastewater transfer pump 11 is operated to drain the wastewater from the wastewater storage tank 10 to the wastewater supply pipe 1, the wastewater transfer pump 11, the wastewater inlet valve V1, and the incoming water. The nozzles 23 are sequentially supplied to the filter unit 20 via the nozzles 23.

Particles having a small size in the wastewater supplied to the filter unit 20 are filtered by passing through the hollow fiber-type separator 22 embedded in the filter unit 20 by the pressure generated in the wastewater transfer pump 11. The filtered permeate is stored in the permeate storage tank 30 via the permeate nozzle 25, the permeate transfer pipe L3, and the permeate valve V3.

Wastewater supplied to the filter unit 20 and not passing through the separation membrane 22 is sequentially passed through the outflow nozzle 24, the wastewater return pipe L2, and the wastewater outlet valve V2 to the wastewater storage tank 10. Circulated.

2) Washing method 1 (backwashing process)

If the filtration process continues to operate, the solid material in the waste water adheres to the surface of the hollow fiber separation membrane 22 to block pores of the separation membrane 22 and the flow rate of the permeate passing through the separation membrane 22 gradually decreases. .

Therefore, backwashing is performed to remove the solid material from the separator 22.

The backwash valve V4 and the drain valve V6 are open, and the wastewater inlet valve V1, the wastewater outlet valve V2, the permeate valve V3, the branch valve V5, the cleanse valve V7, and With the air supply valve V8 closed, the backwash pump 31 is operated to pump the permeate of the permeate reservoir 30 into the backwashing tube L4, the backwash pump 31, the backwash valve V4, and the backwash nozzle. (26) is supplied to the filter part 20 sequentially.

The permeate supplied to the filter unit 20 backwashes the separation membrane 22 in the reverse direction of the permeate flow direction in the filtration process by the pressure generated by the backwash pump 31. Solid material on the surface of the separator 22 is separated from the surface of the separator 22.

The separated solid material is discharged to the outside through the inlet nozzle 23, the drain pipe (L6), the drain valve (V6) in sequence with the permeate liquid is removed.

As another backwashing method, when the concentration of the solid material is not high, the solid material and the permeate mixture may be recovered to the wastewater storage tank 10 without discharging to the outside.

When the waste water outlet valve V2 is opened and the drain valve V6 is closed while the valves are open and closed, the solid material and the permeate mixture are discharged to the nozzle 24, the waste water return pipe L2, and the wastewater outlet valve V2. It is recovered to the wastewater storage tank 10 by sequentially passing.

In another backwashing method, the flow path of the permeate liquid is passed through the permeate nozzle 25 instead of the backwash nozzle 26. In the backwashing process, the branch valve V5 is opened and the backwash valve V4 is closed. The permeate of the lower permeate storage tank 30 includes a backwashing pipe L4, a backwash pump 31, a branch pipe L5, a branch valve V5, a permeate transport pipe L3, and a permeate fluid nozzle 25. It is supplied to the filter part 20 via.

3) Washing 2 method (method of back washing and air washing at the same time)

The backwash valve V4 and the drain valve V6 are open, and the wastewater inlet valve V1, the wastewater outlet valve V2, the permeate valve V3, the branch valve V5, the cleanse valve V7, and With the air supply valve V8 closed, the backwash pump 31 is operated to pump the permeate of the permeate reservoir 30 into the backwashing tube L4, the backwash pump 31, the backwash valve V4, and the backwash nozzle. (26) is supplied to the filter part 20 sequentially.

At the same time, the air compressor 40 is operated and the air supply valve V8 is opened to supply air pressurized by the air compressor 40 to the air supply pipe L8, the air supply valve V8, the waste water recovery pipe L2, The outflow nozzle 24 is sequentially supplied to the filter unit 20 via the outflow nozzle 24.

The permeate supplied to the filter unit 20 backwashes the separator 22 in the reverse direction of the permeate flow direction in the filtration process by the pressure generated by the backwash pump 31, and the air compressor ( Compressed air supplied from 40 is to wash the separation membrane 22 in the reverse direction of the waste water flow direction.

That is, the solid material on the surface of the separator 22 is separated from the surface of the separator 22 in the vertical direction by the backwash of the permeate, and is also separated from the surface of the separator 22 in the parallel direction by washing with air.

As described above, when the permeate backwashing and the air washing are simultaneously performed, the solid material on the surface of the separator 22 is forced to be separated at the same time in the vertical and horizontal directions of the separator 22 so that the separator 22 can be efficiently removed in a short time. Solids can be removed.

The separated solid substance and the permeate are quickly discharged to the outside via the inlet nozzle 23, the drain pipe L6, the drain valve V6 by the compressed air, in particular the liquid at the bottom of the filter unit 20 Solids that may remain in the flow stagnation space are also removed by compressed air.

In the case of backwashing the permeate liquid, as described above in the backwashing step, the permeate liquid may be supplied through the permeate liquid nozzle 25 instead of the backwash nozzle 26.

4) Washing method 3 (air cleaning, cleaning and backwashing sequentially)

Drain valve (V6) is open, waste water inlet valve (V1), wastewater outlet valve (V2), permeate valve (V3), backwash valve (V4), branch valve (V5), washing valve (V7) and In the state in which the air supply valve V8 is closed, the air compressor 40 is operated and the air supply valve V8 is opened to supply air pressurized by the air compressor 40 to the air supply pipe L8 and the air supply valve ( V8), the wastewater recovery pipe L2, and the outflow nozzle 24 are sequentially supplied to the filter unit 20 via the wastewater collection pipe L2.

Compressed air supplied to the filter unit 20 cleans the separation membrane 22 in the reverse direction of the wastewater flow direction by the pressure generated by the air compressor 40.

Solid material separated by the compressed air is quickly discharged to the outside via the inlet nozzle 23, the drain pipe (L6), the drain valve (V6) in sequence with the compressed air, in particular the bottom of the filter unit 20 Solids that may remain in the liquid flow stagnation space are also removed by compressed air.

Next, in the open / closed state of the valves, the air compressor 40 is stopped and the air supply valve V8 is closed, the backwash pump 31 is operated, and the backwash valve V7 is opened to pressurize the backwash pump 31. The permeate of the stored reservoir 30 is passed to the filter unit 20 sequentially through a back washing tube L4, a washing tube L7, a washing valve V7, a wastewater return pipe L2, and an outlet nozzle 24. Supply.

The permeate supplied to the filter unit 20 washes the separation membrane 22 in the reverse direction of the wastewater flow direction by the pressure generated in the backwash pump 31.

The solid material separated by the permeate is discharged to the outside via the inlet nozzle 23, the drain pipe L6, and the drain valve V6 in sequence with the permeate.

Next, in the open / closed state of the valves, the cleansing valve V7 is closed and the backwash valve V4 is opened, so that the permeate of the permeate storage tank 30 is backwashed in the L4, the backwash pump 31, and the backwash valve ( V4) and the reverse nozzle 26 are sequentially supplied to the filter unit 20 via the reverse nozzles 26.

The permeate supplied to the filter unit 20 backwashes the separation membrane 22 in the reverse direction of the permeate flow direction in the filtration process by the pressure generated by the backwash pump 31. Solid material on the surface of the separator 22 is separated from the surface of the separator 22.

The separated solid material is discharged to the outside through the inlet nozzle 23, the drain pipe (L6), the drain valve (V6) sequentially with the permeate.

In the case of backwashing the permeate liquid, as described above in the backwashing step, the permeate liquid may be supplied through the permeate liquid nozzle 25 instead of the backwash nozzle 26.

In the wafer processing wastewater treatment apparatus of the present embodiment operated as described above, the most efficient method for cleaning the separator 22 was derived by measuring the flow rate of the permeate passing through the separator 22.

First, the flow rate of the permeate without washing the separation membrane 22 while performing the filtration process 1) is shown in Table 1 below.

At this time, the wastewater of the wastewater storage tank 10 is wafer cutting wastewater, two kinds of wastewater containing glycol components such as dipropylene glycol (DPG) and polyethylene glycol (PEG) and wastewater containing no glycol components. The hollow fiber type separator 22 was tested with two materials, polyacrylonitrile (PAN) and polysulfone (PS), respectively, and the membrane 22 area was 0.1 m 2, and operated. It was conditions of 0.8 kg / cm <2> of pressure, and 20 degreeC of operation temperature.

With glycol
Permeate Flow Rate (ml / min) of Wastewater Glycol Free
Permeate Flow Rate (ml / min) of Wastewater Separator material Polyacrylonitrile Polysulfone Polyacrylonitrile Polysulfone Driving time Immediately after operation 39 39 162 153 40 minutes 30.5 25 108 53 60 minutes 18 0 38 0 65 minutes 0 0 0 0

As can be seen in Table 1, if the hollow fiber type membrane is continuously operated without washing, the membrane is blocked by the solid material contained in the wastewater and the membrane cannot be operated regardless of the type of the wastewater and the material type of the membrane.

Next, the flow rate of the permeate of the separation membrane 22 was measured while alternately performing 1) the filtration process and 2) the washing method, and the results are shown in Tables 2, 2, and 3 below.

As a result of the measurement in Table 1, polyacrylonitrile (PAN) having a higher filtrate flow rate was used as the separator 22, and the backwashing time was performed for 30 seconds, and the operating conditions of the wastewater and the separator 22 were described in the table. Same as in 1.

With glycol
Permeate Flow Rate (ml / min) of Wastewater Glycol Free
Permeate Flow Rate (ml / min) of Wastewater Driving time Immediately after operation 39.0 162.0 40 minutes 30.5 129.0 Backwash 37.4 158.2 80 minutes 29.5 125.7 Backwash 36.2 153.1 120 minutes passed 28.2 119.3 Backwash 34.7 146.8 160 minutes elapsed 27.3 115.5 Backwash 33.2 140.4 200 minutes 25.9 109.6 Backwash 31.7 134.1

As shown in the results, if backwashing is performed at an interval of 40 minutes, the flow rate is recovered to some extent, but it can be seen that gradually decreases as time passes. Finally, the separation of the filter unit 20 and the separation membrane 22 are required. It can be seen.

Next, the flow rate of the permeate of the separator 22 was measured while alternately performing 1) the filtration process and 3) the washing 2 method.

The washing time was performed for 60 seconds at the same time backwashing and air washing, the operating conditions are the same as in Table 2.

With glycol
Permeate Flow Rate (ml / min) of Wastewater Glycol Free
Permeate Flow Rate (ml / min) of Wastewater Driving time Immediately after operation 39.0 162.0 40 minutes 30.5 129.0 Backwash + Air Wash 38.8 160.4 80 minutes 29.5 124.8 Backwash + Air Wash 38.1 159.3 120 minutes passed 28.6 121.0 Backwash + Air Wash 37.3 158.1 160 minutes elapsed 27.6 116.7 Backwash + Air Wash 36.6 156.4 200 minutes 27.1 114.6 Backwash + Air Wash 35.3 150.8 240 minutes elapsed 26.5 112.1 Backwash + Air Wash 35.0 149.5 280 minutes 26.2 110.8 Backwash + Air Wash 34.4 147.0 320 minutes passed 25.8 109.1 Backwash + Air Wash 34.7 148.2 360 minutes passed 25.4 107.4 Backwash + Air Wash 34.2 146.1 400 minutes 25.0 105.8 Backwash + Air Wash 34.0 145.3 440 minutes have elapsed 24.6 104.1 Backwash + Air Wash 33.7 144.0

Comparing the results of Table 3 with Table 2, it can be seen that the result of Table 3, which was simultaneously backwashed and air-washed, maintained the filtrate flow rate over time, compared to the results of Table 2, which performed only backwashing.

Next, the flow rate of the permeate of the separator 22 was measured while alternately performing 1) the filtration process and 4) the washing method.

The backwashing time was sequentially performed for 30 seconds each for air washing, washing and backwashing, and it took 90 seconds for one backwashing, and the operating conditions are the same as in Table 2 above.

With glycol
Permeate Flow Rate of Wastewater
(Ml / min) Glycol Free
Permeate Flow Rate of Wastewater
(Ml / min) Driving time Immediately after operation 39.0 162.0 40 minutes 30.5 129.0 Air cleaning → cleaning → backwash 38.7 160.5 80 minutes 29.4 124.4 Air cleaning → cleaning → backwash 38.4 159.8 120 minutes passed 29.0 122.7 Air cleaning → cleaning → backwash 38.2 159.4 160 minutes elapsed 28.4 120.1 Air cleaning → cleaning → backwash 38.0 158.8 200 minutes 27.6 116.7 Air cleaning → cleaning → backwash 38.0 158.7 240 minutes elapsed 27.0 114.2 Air cleaning → cleaning → backwash 37.9 158.4 280 minutes 26.5 112.1 Air cleaning → cleaning → backwash 37.7 158.0 320 minutes passed 26.3 111.2 Air cleaning → cleaning → backwash 37.4 157.9 360 minutes passed 25.8 109.1 Air cleaning → cleaning → backwash 37.2 157.4 400 minutes 25.4 107.4 Air cleaning → cleaning → backwash 36.8 155.7 440 minutes have elapsed 25.2 106.6 Air cleaning → cleaning → backwash 36.9 156.1

It can be seen that the results of Table 4, which sequentially perform air washing, cleaning, and backwashing, are much more effective for washing the membrane than the results of Table 2, which was only backwashing.

In addition, in comparison with the results of Table 3, in the flow rate recovery after washing, the three washing methods that sequentially perform air washing, washing and back washing are judged to be more effective than the washing two methods that simultaneously carry out back washing and air washing. As the backwashing time becomes longer, the flow rate before washing can be seen that both washing method 2 and washing method 3 are very effective for washing the separation membrane when Table 3 and Table 4 show no significant difference. .

In more detail, the flow rate immediately after washing is larger than the washing 3 method compared to the washing 2 method, and since the flow rates are similar to each other during operation, it is determined that the washing 3 method is more efficient in the flow rate integration, that is, the total amount of permeate.

Based on the above analysis results, the initial flow rates were 39.0 ml / min and 162.0 ml / min, respectively. After 200 minutes of operation, the flow rate of permeate was 31.7 ml / min. And 134.1 ml / min, washing 2 method (method of backwashing and air washing at the same time) is 35.3 ml / min and 150.8 ml / min, washing 3 method (method of air washing, washing and backwashing sequentially) is 38.0. Recovery rates as ml / min and 158.7 ml / min were 81% and 82%, 90% and 93%, 97% and 98%, respectively.

From the above results, the method of washing during operation of the hollow fiber membrane is performed by simultaneously performing the back washing and the air washing in the washing 2 method or the air washing, the washing and the back washing in the washing method 3, rather than the simple back washing in the washing method 1. It can be seen that it is an effective method.

As described above, the measurement has been described with respect to the apparatus and method for regenerating and cleaning the wafer cutting waste water, but the regeneration target is not only the wafer cutting waste water, but also the wafer with the cutting liquid after the wafer cutting process. It can be applied to cleaning waste water generated in the process of cleaning, and can be applied to solution waste containing solid material, thus contributing to preventing resource depletion, environmental protection and cost reduction.

10: wastewater storage tank, 11: wastewater transfer pump, 20: filter part, 21: body, 22: separator, 23: inlet nozzle, 24: outflow nozzle, 25: permeate nozzle, 26: backwash nozzle, 30: permeate storage tank , 31: backwash pump, 40: air compressor, 100: separator device,
L1: wastewater supply pipe, L2: wastewater recovery pipe, L3: permeate transfer pipe, L4: backwashing pipe, L5: branch pipe, L6: drainage pipe, L7: cleaning pipe, L8: air supply pipe,
V1: wastewater inlet valve, V2: wastewater outlet valve, V3: permeate valve, V4: backwash valve, V5: branch valve, V6: drain valve, V7: washing valve, V8: air supply valve

Claims (7)

Wastewater storage tank 10 for storing wastewater, the filter unit 20 for receiving the wastewater from the wastewater storage tank 10 and filtering using a built-in hollow fiber membrane, the wastewater of the filter unit 20 to the hollow fiber membrane A permeate storage tank (30) for storing the permeate filtered while being permeated, and an air compressor (40) for washing the filter unit (20);
The permeate transport tube L3 through which the permeate that has passed through the hollow fiber membrane of the filter part 20 is transferred to the permeate storage tank 30, and the permeate of the permeate storage tank 30 is the filter portion 20. Backwashing pipe (L4) supplied to) is connected to the circulation by the branch pipe (L5);
During the wastewater recovery pipe L2 in which the wastewater that does not penetrate the hollow fiber membrane of the filter unit 20 is transferred to the wastewater storage tank 10, the permeate of the permeate storage tank 30 is transferred to the filter unit 20. The fine pipe (L7) for supplying the hollow fiber membranes in the reverse direction of the wastewater flow direction and the air for supplying the pressurized air from the air compressor 40 to the hollow fiber membranes of the filter unit 20 in the reverse direction of the wastewater flow direction. Wafer processing wastewater treatment apparatus, characterized in that the supply pipe (L8) is connected. The method of claim 1, wherein the filter unit 20,
Tubular body 21 having an inner space;
A plurality of hollow fiber separation membranes 22 installed in the inner space of the body 21 to allow particulate matter of a small size in the wastewater to permeate;
An inlet nozzle 23 installed at a lower end of the body 21 to introduce wastewater from the wastewater storage tank 10;
An outflow nozzle 24 installed at an upper end of the body 21 to allow wastewater that has not passed through the separation membrane 22 to flow out;
A permeate nozzle (25) installed on the outer circumferential surface of the body (21) to discharge the permeate from the wastewater through the separation membrane (22); And
Wafer processing wastewater treatment apparatus is installed in the lower outer peripheral surface of the body 21 and comprises a backwash nozzle (26) for cleaning the separation membrane (22). The method according to claim 2,
The wastewater storage tank 10 has one end connected to the inlet nozzle 23 and the other end of the wastewater supply pipe L1 having the wastewater transfer pump 11 interposed therebetween to be circulated with the filter unit 20. Connected;
The wastewater inlet valve V1 is interposed between the inlet nozzle 23 and the transfer pump 11 of the wastewater supply pipe L1, and the inlet nozzle 23 and the wastewater inlet valve V1 of the wastewater supply pipe L1 are interposed. One end flows to the outside and the other end of the drain pipe L6 with the drain valve V6 interposed therebetween is connected;
The outflow nozzle 24 of the filter unit 20 has one end connected to the wastewater storage tank 10 and the other end of the wastewater return pipe L2 having the wastewater discharge valve V2 interposed therebetween so that the wastewater storage tank ( 10) circulating in circulation;
One end of the permeate fluid nozzle 25 of the filter unit 20 is connected to the permeate fluid storage tank 30, and the other end of the permeate fluid transfer pipe L3 having the permeate fluid valve V3 interposed therebetween is connected to the above. It is connected to the permeate storage tank 30 and circulating;
The backwash nozzle 26 of the filter unit 20 has one end connected to the permeate storage tank 30 and the other end of the backwash tube L4 having the backwash pump 31 interposed therebetween so that the permeate storage tank ( 30), and a backwash valve (V4) is interposed between the backwash nozzle (26) and the backwash pump (31) of the backwash pipe (L4);
One end is connected between the outflow nozzle 24 of the wastewater return pipe L2 and the wastewater outlet valve V2, and the other end thereof is connected between the backwash valve V4 and the backwash pump 31 of the backwashing pipe L4 to each other. A fine pipe (L7) connected to the circulation and interposed with a fine valve (V7);
One end is connected between the outflow nozzle 24 and the wastewater outlet valve V2 of the wastewater return pipe L2, and the other end is connected to the air compressor 40 so as to be circulated so that the air supply valve V8 is on the way. Wafer processing wastewater treatment apparatus, characterized in that the air supply pipe (L8) interposed. The method according to claim 3,
One end is connected between the backwash pump 31 of the backwashing pipe L4 and the backwash valve V4 and the other end is connected between the permeate fluid 25 and the permeate valve V3 of the permeate transfer pipe L3. Wafer processing wastewater treatment apparatus, characterized in that the branch pipe (L5) is further connected is connected to each other so as to flow through each other and the branch valve (V5) is interposed. The method according to claim 3 or 4,
Wafer processing wastewater treatment apparatus, characterized in that one end is connected to the permeate storage tank (30), the other end is connected to a washing pipe (L7) upstream of the washing valve (V7), and the pump is interposed. delete Wastewater storage tank for storing wastewater, Filter unit for receiving the wastewater of the wastewater storage tank and filtering using the built-in hollow fiber membrane, Permeate for storing the filtered permeate while the wastewater supplied to the filter unit penetrates the hollow fiber membrane In the method for operating a wafer processing wastewater treatment apparatus comprising a liquid reservoir and an air compressor for cleaning the filter portion,
Blocking wastewater supply to the filter unit and discharging wastewater inside the filter unit to the outside;
Discharging the air pressurized by the air compressor to the hollow fiber membrane of the filter unit in the reverse direction of the waste water flow direction and discharged to the outside;
Shutting off the air supply and discharging the permeate of the permeate reservoir to the hollow fiber membrane of the filter part in a reverse direction of the wastewater flow direction and then discharging the permeate to the outside;
And discharging the permeate supply and discharging the permeate of the permeate reservoir to the hollow fiber membrane of the filter part in a reverse direction in a flow direction through which the waste water permeates.

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