JP2003286967A - High-pressure extrapure water manufacturing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture high-pressure extrapure water while restricting quantity of particulates in such a range as to cause no trouble in cleaning silicon substrates and glass substrates. <P>SOLUTION: This device is provided with a pressure transmitting part to transmit pressure of liquid pressurized by a high pressure pump to extrapure water refined in an extrapure water refining device, a suction side check valve provided in an extrapure water feed tube to feed extrapure water into the pressure transmitting part, and a discharge side check valve provided in high pressure extrapure water discharge piping to discharge extrapure water pressurized in the pressure transmitting part. As the discharge side check valve 52a or 52b, the one comprising a valve element 16 to get in surface-contact with a valve seat 14 is used, and at least either of the valve element 16 and the valve seat 14 is composed of high polymer material. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for producing high-pressure ultrapure water used for producing high-pressure ultrapure water used for processing and cleaning semiconductor substrates and glass substrates.

[0002]

2. Description of the Related Art Recently, there has been proposed a technique for removing (cleaning) contaminated fine particles, metal or the like adhering to the surface of a silicon wafer or the like by utilizing a high-speed shearing flow of high-pressure ultrapure water. For such cleaning, ultrapure water (pressurized ultrapure water) pressurized to a pressure that cannot be applied by an ordinary rotary pump, for example, 1 MPa.
Is used.

Here, ultrapure water is purified by removing dissolved gas, bacteria, fine particles, ions and the like in water using a module such as a reverse osmosis membrane, a degassing membrane, an ultraviolet lamp, a filter and an ion exchange resin. It Therefore, when trying to produce high-pressure ultrapure water with a generally widely used ultrapure water purification device, there is a problem in the pressure resistance of these modules, and it is quite difficult to directly produce high-pressure ultrapure water. is there.

Therefore, the pressure of tap water pressurized to a predetermined pressure by the high-pressure pump is transmitted to the ultrapure water through the flexible bellows arranged inside the pressure vessel to pressurize the ultrapure water. Has been proposed to produce high-pressure ultrapure water at a desired pressure. The production apparatus for producing such high-pressure ultrapure water is provided with various pipes for circulating the ultrapure water before and after pressurization, and at a predetermined position inside the pipe, a reverse flow that prevents the reverse flow of the ultrapure water is provided. A stop valve is arranged. And, in order to withstand the pressure of high-pressure ultrapure water, members such as these pressure transmitting parts, pipes, and check valves that come into contact with high-pressure ultrapure water are generally made of metal such as stainless steel. ing.

FIG. 9 shows a conventional general structure of a check valve installed in the middle of this kind of piping. The check valve 10 is installed in the middle of the piping and It has a cylindrical valve block 12 forming a part. A valve seat 14 is fixed inside the valve block 12, and a valve body 16 that opens and closes the flow path by contacting and separating from the valve seat 14 is disposed on the upstream side in the flow direction of the valve seat 14. There is. This valve body 1
6 has a plurality of flow holes 18a, is integrally connected to the valve seat 14 side end of the valve rod 20 which is guided by the guide 18 fixed to the valve block 12, and is movable in the axial direction. 1
A valve spring 22 that urges the valve element 16 toward the valve seat 14 is arranged between the guide 6 and the guide 18. Furthermore, the valve seat 1
The arc-shaped abutting portion 14a is provided on the surface of the No. 4 facing the valve body 16,
The hemispherical contact portion 1 is provided on the surface of the valve body 16 facing the valve seat 14.
6a are provided respectively.

As a result, when the pressure on the upstream side of the check valve 10 inside the pipe in which the check valve 10 is mounted becomes higher and the elastic force of the valve spring 22 is overcome, the elastic force of the valve spring 22 is resisted. Release the contact of the valve element 16 with the valve seat 14 to open the flow path, and otherwise, the elastic force of the valve spring 22 presses the valve element 16 toward the valve seat 14 to bring them into contact with each other. , 16a are circularly in line contact to close the flow path. Here, the valve seat 14 and the guide 18 are, for example, SUS.
Made of 304, the valve element 16 and the valve rod 20 are made of, for example, SUS3.
The valve spring 22 is made of 16 and its spring constant is set to, for example, 1.0 kgf / cm.

[0007]

However, as in the conventional example, a high-pressure ultrapure water producing apparatus is used in which a member that comes into contact with high-pressure ultrapure water is made of metal such as stainless steel in consideration of pressure resistance. When high-pressure ultrapure water is produced, the amount of fine particles contained in the high-pressure ultrapure water is generally the same as the amount of fine particles contained in the high-pressure ultrapure water (generally , The number of fine particles with a diameter of 0.1 μm or less is 1
It was found that the number of cells increased about 1000 times (about 1 in ml). Then, when high pressure ultrapure water containing such a large amount of fine particles is used to wash, for example, a silicon wafer with an ultrahigh speed shear flow, the fine particles contained in the high pressure ultrapure water adhere to the surface of the silicon wafer and are washed. Will be an obstacle.

Here, when high-pressure ultrapure water was manufactured by inserting the check valve having the structure shown in FIG. 9 in the pipe of the high-pressure ultrapure water manufacturing apparatus, it is thought that the high pressure ultrapure water is due to the flow of water in the seal portion. There were traces of erosion (destruction) in the guide, which were thought to be due to the valve rod sliding with the opening and closing of the check valve.

The present invention has been made in view of the above, and it is possible to manufacture high-pressure ultrapure water in which the amount of fine particles in a liquid is suppressed within a range that does not hinder cleaning of a silicon substrate or a glass substrate. It is an object of the present invention to provide a high-pressure ultrapure water production system as described above.

[0010]

According to a first aspect of the present invention, there is provided a pressure transmission section for transmitting the pressure of a liquid pressurized by a high pressure pump to ultrapure water purified by an ultrapure water purification apparatus,
A suction-side check valve interposed in the ultrapure water supply pipe for supplying ultrapure water into the pressure transmission unit, and a high-pressure ultrapure water discharge pipe for discharging the ultrapure water pressurized by the pressure transmission unit. An intervening discharge side check valve is used, and as the discharge side check valve, a valve body in which the valve body makes surface contact with a valve seat is used, and at least one of the valve body and the valve seat is made of a polymer material. This is a high-pressure ultrapure water production system characterized by the above.

Since the check valve installed in the pipe repeats the opening / closing operation, if the seal portion composed of the valve seat and the valve body is made of metal and the contact area of the seal portion is small, the check valve is opened / closed every time. Metals collide with each other with a considerably high contact surface pressure and metal destruction occurs little by little, which causes contamination of fine particles.
As mentioned above, it is probable that erosion (destruction), which is thought to be due to the flow of water, was observed in the seal part. In particular, the check valve on the discharge side prevents the reverse flow of high-pressure ultrapure water.
The high-pressure ultrapure water acts directly, and this tendency becomes remarkable. Therefore, as the discharge side check valve, use one in which the valve body makes surface contact with the valve seat, and make the contact area of the seal part as large as possible.
The contact surface pressure of the seal part at the time of opening and closing is kept low, and at least one of the valve body and valve seat is made of a polymeric material to avoid collision between metals, thereby reducing particulate contamination due to metal destruction of ultrapure water. be able to.

According to a second aspect of the present invention, there is provided a pressure transmitting portion for transmitting the pressure of the liquid pressurized by the high pressure pump to the ultrapure water purified by the ultrapure water purifying device, and an ultrapure water inside the pressure transmitting portion. Suction-side check valve installed in the ultrapure water supply pipe for supplying pure water, and discharge-side check valve installed in the high-pressure ultrapure water discharge pipe for discharging the ultrapure water pressurized by the pressure transmission unit. With a stop valve,
As the suction side check valve, a valve body in which a valve body is in surface contact with a valve seat is used, and at least one of the valve body and the valve seat is made of a polymer material. Is.

As a result, even in the check valve on the suction side,
By making the contact area of the seal part as large as possible to suppress the contact surface pressure of the seal part at the time of opening and closing, and avoiding collision between metals, it is possible to prevent particulate contamination due to metal destruction of ultrapure water as much as possible. .

According to a third aspect of the present invention, a guide for sliding the valve rod of the discharge side check valve and / or the suction side check valve to guide the valve rod is provided. 3. The high pressure ultrapure water production system according to claim 1, wherein at least one of the valve rod and the guide is made of a polymer material.

If both the valve rod connected to the valve body of the check valve and the guide for sliding the valve rod and guiding the valve rod are made of metal,
Each time the check valve is opened and closed, the metals slide against each other, causing metal wear due to this sliding and causing particulate contamination.
As mentioned above, it is probable that sliding marks were seen on the guide.
Therefore, at least one of the valve rod and the guide is made of a polymeric material to avoid sliding between metals, so that it is possible to reduce particulate contamination due to metal wear of ultrapure water.

According to a fourth aspect of the present invention, a plurality of pressure transmitting portions for transmitting the pressure of the liquid pressurized by the high pressure pump to the ultrapure water purified by the ultrapure water purifying device, and the pressure transmitting portions. Intake side check valves respectively installed in the ultrapure water supply pipes for supplying ultrapure water into the parts, and high pressure ultrapure water discharge pipes for discharging the ultrapure water pressurized by the pressure transmission parts, respectively. And a suction side check valve and / or the discharge side provided on the other side of the pressure transmission section at the pressure of the ultrapure water discharged from one of the pressure transmission sections. A high-pressure ultrapure water production system characterized in that a check valve is closed.

As described above, by closing the suction side check valve and / or the discharge side check valve of the other pressure transmitting section with the pressure of the ultrapure water discharged from the one pressure transmitting section, the pressure acting as the discharge valve. It is possible to use a metal valve spring that does not use any metal, so that the surface of the metal valve spring is roughened or polished due to the flow of high-pressure ultrapure water, resulting in fine particle contamination. It is possible to eliminate the drawbacks such as the connection, which are associated with the use of the discharge valve using the metal valve spring, and reduce the contamination of the ultrapure water particles.

According to a fifth aspect of the invention, as the suction side check valve and / or the discharge side check valve, a valve body in which a valve body is in surface contact with a valve seat is used, and the valve body and the valve seat are also used. 5. The high pressure ultrapure water production system according to claim 4, wherein at least one of the above is made of a polymer material.

According to a sixth aspect of the present invention, there is provided a pressure transmitting portion for transmitting the pressure of the liquid pressurized by the high pressure pump to the ultrapure water purified by the ultrapure water purifying device, and an ultrapure water inside the pressure transmitting portion. Suction-side check valve installed in the ultrapure water supply pipe for supplying pure water, and discharge-side check valve installed in the high-pressure ultrapure water discharge pipe for discharging the ultrapure water pressurized by the pressure transmission unit. With a stop valve,
The polymer contacting portion of the pressure transmitting portion with the ultrapure water and the portion of the piping located downstream of the suction side check valve and upstream of the discharge side check valve with the ultrapure water are made of polymer. It is a high-pressure ultrapure water production system characterized by being made of a material.

If a metal is used in the pressure transmission device or in the ultrapure water pipe where the ultrapure water comes into contact, the surface of the metal is roughened or polished by the high-speed and high-speed flow of the ultrapure water. This phenomenon is particularly noticeable at the corners of the flow path where the flow is sharply bent. Therefore, by making the liquid contact portion with ultrapure water, in which this phenomenon is particularly noticeable, made of a polymer material, it is possible to reduce the contamination of fine particles of ultrapure water.

According to a seventh aspect of the present invention, the high pressure ultrapure water of the sixth aspect is characterized in that the liquid contact portion of the pipe located downstream of the discharge side check valve is made of a polymer material. It is a manufacturing device. As a result, by making the liquid contact portion with high-pressure and high-speed ultrapure water made of a polymer material, it is possible to reduce the contamination of ultrapure water with fine particles.

The invention according to claim 8 is characterized in that the polymer material is a fluororesin or polyetheretherketone, and the high pressure according to any one of claims 1, 2, 3, 5 and 6. It is an ultrapure water production system. As described above, by using the fluororesin having excellent wear resistance, it is possible to prevent fine particles from being mixed in the high-pressure ultrapure water.
Examples of the fluororesin include PVDF (polyvinylidene fluoride: polyvinylidene fluoride resin) and PT.
FE (polytetrafluoroethylene: tetrafluoroethylene resin) may be mentioned. PEEK (polyetheretherketone) has the same ability as PVDF and has good moldability, and thus can be used in place of the fluororesin.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the overall configuration of a high-pressure ultrapure water production system according to an embodiment of the present invention. This high-pressure ultrapure water production system includes two pressure transmission parts 30a, 3 having substantially the same configuration.
It has 0b. It should be noted that in the following description, each member constituting the one pressure transmitting portion 30a and the pressure transmitting portion 30a.
The various pipes connected to the above will be described by adding alphabets a to the numbers, and each member of the other pressure transmitting portion 30b constituting the one pressure transmitting portion 30a and the pressure transmitting portion 30a.
The same numbers are attached to the same members as the various pipes connected to, and the description thereof is partially omitted.

The pressure transmitting portion 30a has a pressure vessel 34a having a lid 32a, and the pressure vessel 34a is provided with, for example, a flexible bellows 36a made of PTFE, and ultrapure water inside the bellows 36a. Chamber 38a and bellows 36a
And a working fluid chamber 40a between the pressure vessel 34a and the pressure vessel 34a. Then, in the ultrapure water chamber 38a, an ultrapure water supply pipe 46a branched from an ultrapure water discharge pipe 44 connected to the ultrapure water purification device 42 to supply ultrapure water to the ultrapure water chamber 38a, A discharge pipe 48a for high-pressure ultrapure water that discharges the pressurized ultrapure water in the ultrapure water chamber 38a is connected to the ultrapure water supply pipe 46a.
An intake side check valve 50a is provided in the middle of the above, and a discharge side check valve 52a is provided in the middle of the high pressure ultrapure water discharge pipe 48a. In this example, the common pipe 54a that also serves as the ultrapure water supply pipe 46a and the high-pressure ultrapure water discharge pipe 48a is connected to the ultrapure water chamber 38a, but they are connected separately. Of course, you can do that.

The high-pressure ultrapure water discharge pipe 48a is connected to a single high-pressure ultrapure water supply pipe 56, and the high-pressure ultrapure water flowing through the high-pressure ultrapure water discharge pipe 48a is a high-pressure ultrapure water. The water is supplied from the water supply pipe 56 to the inside of the cleaning container 58 of the cleaning system.

On the other hand, the working fluid chamber 40a is supplied with a city water supply pipe 62a for supplying high-pressure city water into the working fluid chamber 40a through a high pressure pump 60 such as a plunger pump, and a discharge pump 64 such as a gear pump. City water discharge pipes 66a for discharging city water therein are connected to each other, and a suction drive valve 68a is provided in the middle of the city water supply pipe 62a, and a discharge drive valve 70a is provided in the middle of the city water discharge pipe 66a. It is equipped.

A control cylinder 72a is connected to the pressure vessel 34a, and a metal gauge rod 74a is connected to the bellows 36a which moves along the length of the control cylinder 72a as the bellows 36a expands and contracts. , And control cylinder 72a
At the predetermined positions along the length direction thereof, metal passage sensors 76a and 78a for position detection and metal passage sensors 80a and 82a for interlock are attached, respectively. In addition, the pressure vessel 34a has a degassing pipe 8 for degassing the ultrapure water chamber 38a and the working fluid chamber 40a.
3a, 84a and a pressure release pipe 86a for releasing the pressure in the working fluid chamber 40a are connected to each other.

Next, the operation of this high-pressure ultrapure water production system will be described with reference to FIGS. In addition, in each valve of the same figure, the open valve shows the valve closed state, and the valve with dots inside shows the valve opened state. , 84b and the pressure relief pipes 86a, 86b, respectively,
Open for a few seconds only immediately before high-pressure city water discharge.

First, as shown in FIG. 2 (a), only the city water discharge drive valves 70a and 70b are opened, and the discharge pump 64 is driven to drive the pressure vessels 34 of the pressure transmission portions 30a and 30b.
The city water in the working fluid chambers 40a, 40b in a, 34b is discharged. Then, both of the suction side check valves 50a and 50b on the pressure transmitting portions 30a and 30b side are opened, and the pressure transmitting portion 30
Ultrapure water chamber 38 in a bellows 36a, 36b of a, 30b
Ultrapure water is supplied into a and 38b.

Next, as shown in FIG. 2 (b), the city water discharge drive valves 70a and 70b are closed, and one pressure transmission portion 30 is closed.
The a-side high pressure city water suction drive valve 68a is opened to supply the high pressure city water pressurized by the high pressure pump 60 into the working fluid chamber 40a of the pressure vessel 34a. As a result, the pressure of the city water supplied into the working fluid chamber 40a is transmitted to the ultrapure water in the ultrapure water chamber 38a via the bellows 36a to pressurize the ultrapure water and apply the pressure in the bellows 36a. The pressurized ultrapure water is supplied to the cleaning system through the discharge side check valve 52a. At this time, the pressure transmitting portion 30a is activated by the pressurized ultrapure water.
Side suction side check valve 50a is closed to prevent backflow of ultrapure water, and the pressure transmission section 30b side suction side check valve 50b and discharge side check valve 52b are closed so that pressure transmission section 30b is It becomes inactive.

Then, as shown in FIG. 2 (c), the bellows 36a of the pressure transmitting portion 30a contracts, and the gauge rod 74a
When it is detected that the gas has deviated from the metal passage sensor 76a, the suction drive valve 68a on the pressure transmission portion 30a side is closed and the discharge drive valve 70a is opened, thereby discharging city water in the working fluid chamber 40a. . At this time, at the same time, the suction side check valve 50a is opened to supply ultrapure water into the ultrapure water chamber 38a in the bellows 36a. On the other hand, on the pressure transmitting portion 30b side, the high-pressure city water suction drive valve 68b is opened to supply the high-pressure city water pressurized by the high-pressure pump 60 into the working fluid chamber 40b of the pressure vessel 34b. Thus, the pressure of the city water supplied into the working fluid chamber 40b is transmitted to the ultrapure water in the ultrapure water chamber 38b via the bellows 36b to pressurize the ultrapure water, and pressurize in the bellows 36b. The obtained ultrapure water is supplied to the cleaning system through the discharge side check valve 52b. At this time, the pressurized ultrapure water causes the pressure transmitting portion 30b to
Side suction side check valve 50b is closed to prevent backflow of ultrapure water, and discharge side check valve 52a on the pressure transmitting portion 30a side is closed.

Next, as shown in FIG. 3A, when it is detected that the bellows 36a of the pressure transmitting portion 30a extends and the gauge rod 74a has passed the metal passage sensor 78a, the city water discharge drive valve 70a. Close. At the same time, the suction side check valve 50a is also closed, and the ultrapure water chamber 38 in the bellows 36a is closed.
The supply of ultrapure water into a is stopped. At this time, high-pressure ultrapure water is continuously supplied to the cleaning system on the pressure transmitting portion 30b side.

Then, as shown in FIG. 3B, the bellows 36b on the pressure transmitting portion 30b side is contracted, and the gauge rod 74 is
When it is detected that "b" has come off the metal passage sensor 76b, the high pressure city water suction drive valve 68b on the pressure transmitting portion 30b side is detected.
Is closed, the city water discharge drive valve 70b is opened, and city water in the working fluid chamber 40b is discharged. At this time, at the same time, the suction drive valve 68a on the side of the pressure transmitting portion 30b is opened to open the bellows 36a.
Ultrapure water is supplied into the ultrapure water chamber 38a therein, and in the same manner as described above, the ultrapure water pressurized in the bellows 36a is supplied to the cleaning system through the discharge side check valve 52a.

FIG. 4 shows the discharge side check valve 52a (52a).
The details of b) are shown. That is, the difference between the check valve 52a and the conventional general check valve shown in FIG.
The guide 18 is made of PVDF having excellent wear resistance and low frictional characteristics, and the valve spring 22 is set to have a spring constant of 0.5 kgf / cm. A notch-shaped tapered surface 14b is provided on a surface of the valve seat 14 facing the valve body 16 and a spire-shaped tapered surface 16b is provided on a surface of the valve body 16 facing the valve seat 14, so that the valve body 16 is a valve. When sitting on the seat 14, both 14,
16 is in a point of being in surface contact via the tapered surfaces 14b and 16b. Other configurations are almost the same as the conventional example shown in FIG.

That is, the conventional check valve 10 having the general structure shown in FIG. 9 is used as the discharge side check valve 52a (52b) of the high-pressure ultrapure water producing apparatus shown in FIG. As a result of production, it was found that the amount of fine particles contained in the high-pressure ultrapure water was increased to about 1,000 times the amount of fine particles contained in the normal pressure ultrapure water. Furthermore, when the check valve 10 after use was visually confirmed, erosion (destruction), which is considered to be caused by the flow of water in the seal portion, was caused by the valve rod sliding on the guide as the check valve opened and closed. The sliding traces that seemed to be each were seen. Further, it was found from the sliding trace of the valve rod 20 and the guide 18 that the opening / closing stroke of the valve was 2 mm or less.

Therefore, in this example, when the valve body 16 is seated on the valve seat 14, the two 14, 16 are tapered surfaces 14b, 16b.
The contact area of the seal portion is increased as much as possible by contacting the surface of the seal portion with each other so as to suppress the contact surface pressure of the seal portion at the time of opening and closing, and the valve seat 14 is made of a polymer material other than metal. The guide 18 is made of a polymer material other than metal, that is, PVDF, so as to avoid collision between metals, and the guide 18 is made of PVDF so as to avoid sliding between metals. It is possible to reduce particulate contamination of ultrapure water due to abrasion. Further, the valve spring 22 has a spring constant smaller than that of a conventional valve spring (1.0 kgf / cm).
By using the one set to 0.5 kgf / cm,
The opening and closing stroke of the valve can be increased so that the flow of water at the seal part can be slowed down to prevent eating. The spring constant of this valve spring is
You may use what was set to the smaller 0.25 kgf / cm.

Note that this example shows an example in which the check valve shown in FIG. 4 is used as the discharge side check valve 52a (52b) shown in FIG. This is especially true of the discharge side check valve 52a (52
b) prevents the backflow of ultrapure water that has become high pressure.
This is because the high-pressure ultrapure water acts directly on the metal, which easily causes metal destruction that causes particulate contamination. By using the check valve shown in FIG. 4 as the suction side check valve 50a (50b) shown in FIG. 1, this suction side check valve 50a (50b)
The generation of metal particles from the inside may be prevented.

Further, in this example, PV is a high molecular material other than metal, which is a kind of fluororesin having excellent wear resistance.
Although an example using DF is shown, PTFE, which is a kind of fluororesin, is used instead of PVDF,
PEEK having the same ability as PVDF and excellent moldability may be used. This also applies to each of the following examples.

5 and 6 show the discharge side check valve 52a (5
2b) and, if necessary, the suction side check valve 50a (5
Another example of the check valve suitable for use in 0b) will be shown. This check valve differs from the check valve shown in FIG. 4 in that the valve element 16 and the valve rod 20 are, for example, a metal mandrel 90 made of SUS304.
The surroundings of PVDF are integrally covered with PVDF coatings 92a and 92b, and the contact portions of the coatings 92a and 92b are P
The point is that a welding unit 94 made of TFE is integrally welded. Furthermore, according to this example, as the valve spring 22, a spring whose spring constant is set to 0.25 kgf / cm is used.

As described above, the valve body 16 and the valve rod 20 are not made of PVDF having excellent wear resistance and low frictional characteristics, and the valve seat 14 and the guide 18 are also made of PVDF. Opening and closing and sliding of the valve rod 20 with respect to the guide 18 are performed by contacting PVDFs with each other, whereby the number of fine particles existing in the produced high-pressure ultrapure water can be significantly reduced. Moreover, the metal mandrel 90 embedded inside
By reinforcing with, the valve body 16 and the valve rod 20 can be made to have sufficient strength.

FIG. 7 shows the discharge side check valve 52a (52b),
Furthermore, still another example of a check valve suitable for use in the suction side check valve 50a (50b) will be shown as needed. In this, all the liquid contact parts inside the check valve are made of PVDF.
That is, the check valve has a bottomed cylindrical shape made of, for example, SUS304, and has a suction port 100 at the center of the end faces facing each other.
It has a valve block 100 having a and a discharge port 100b. A valve seat 102 and a guide retainer 104 are attached to the inner peripheral surface of the valve block 100 so as to cover the entire inner peripheral surfaces including the inner peripheral surfaces of the suction port 100a and the discharge port 100b. A substantially flat plate-shaped guide 106 having a flow hole 106a is arranged so as to cross the inside of the valve block 100, and the peripheral portion thereof is sandwiched and fixed between the valve seat 102 and the guide retainer 104. Inside the valve block 100, a valve body 1 having a tapered surface 108a that opens and closes a flow path by contacting and separating from the tapered surface 102 of the valve seat 102.
08 is arranged, and the valve rod 110 integrally connected to the valve body 108 is guided by the guide 106 to move in the axial direction. The valve seat 102, the guide retainer 104, the guide 106, and the integrated valve body 108 and valve stem 110 are made of PVDF having excellent wear resistance.

This check valve is used, for example, as the discharge side check valve 52a (52b) shown in FIG. 1, and is opened and closed by pressurized ultrapure water. That is,
For example, when it is used as the discharge side check valve 52a on the pressure transmitting portion 30a side shown in FIG. 1, when pressurized ultrapure water is discharged from this pressure transmitting portion 30a, the valve is operated by the pressure of this ultrapure water. When the body 108 is lifted from the valve seat 102 to open the valve and the pressurized ultrapure water is discharged from the pressure transmitting portion 30b,
The valve body 108 is pressed against the valve seat 102 by the pressure of this ultrapure water to close the valve.

When a metal spring is used as the valve component, the surface of the spring is roughened or polished due to the flow of ultrapure water, and metal fine particles may be mixed in the high-pressure ultrapure water. By using a polymeric material such as PVDF for all parts of the valve parts that come in contact with ultrapure water without using metal springs,
It is possible to prevent the metal fine particles from mixing into the high-pressure ultrapure water.

FIG. 8 shows a main part of a high-pressure ultrapure water producing system according to another embodiment of the present invention. In this example, the suction side check valve 50a and the discharge side check valve 52b on the pressure transmission section 30a side shown in FIG.
A material made of a polymer such as VDF is used, and the flow path on the upstream side of the suction side check valve 50a and on the downstream side of the discharge side check valve 52a is in contact with ultrapure water (high pressure ultrapure water). The liquid portion is made entirely of a polymer material such as fluororesin.

That is, the suction side of the suction side check valve 50a is
The discharge side is connected to the connection block 112 via the PVDF bush 111, and the discharge side has ETFE lining portions 114a, 116a, 11 with ETFE lined on the inner wall surface of the flow path.
Three flow path forming blocks 114, 11 having 8a
It is connected to one end of the flow path constituted by 6,118. And three flow path forming blocks 114, 116, 118
A vertically branched flow path is formed at the other end of the flow path constituted by 1. The discharge-side check valve 52a is connected to the branched flow path, and the other flow path is provided with ETFE on the inner wall surface of the flow path. A block 120 having a lined ETFE lining portion 120a is connected, and the ultrapure water chamber 38a in the bellows 36a shown in FIG. 1 is connected to the flow path via the block 120. Further, the discharge side check valve 52a
The discharge side of is connected to the connection block 124 via the PVDF bush 122.

Although not shown, ETFE is also formed on the inner wall surface of the flow path that connects the block 120 and the ultrapure water chamber 38a in the bellows 36a and the surface of the lid 32a on the bellows 36a side.
Has been lined.

SUS3 is used for the conventional general ultrapure water flow path.
Although 16 pipes are used that have been treated with Gold EP (a surface treatment method in which the liquid contact part is electrolytically polished and then passivated), in this example, the ultra pure water liquid contact part inside the pressure transmission device is The SUS316L is changed to a fluororesin lining, which can significantly reduce the contamination of the high-pressure ultrapure water with fine particles.

Example 1 High-pressure ultrapure water was produced using the apparatus for producing high-pressure ultrapure water shown in FIG. 1, and the number of fine particles contained in the produced high-pressure ultrapure water was measured. That is, in this ultrapure water production system, the discharge side check valves 52a, 52a
As the b, the check valve shown in FIG. 4 is used, and further, ultrapure water supply pipes 46a, 46b located downstream of the suction side check valves 50a, 50b, which are the parts in contact with the high pressure ultrapure water, As the high-pressure ultrapure water discharge pipes 48a, 48b and the high-pressure ultrapure water supply pipe 56, pipes made of SUS316 material and treated with Gold-EP were used.

The number of the fine particles is measured by storing the high-pressure ultrapure water produced in the cleaning container 58 shown in FIG. 1 and the particle diameter contained in 1 cc of this ultrapure water is 0.10 to 0.15 μm.
m, 0.15 to less than 0.20 μm, 0.20 to 0.
Less than 30 μm and less than 0.30 to 0.50 μm, 0.5
It was carried out by counting the number of fine particles of 0 μm or more. This also applies to each of the following embodiments.

(Example 2) The high-pressure ultrapure water supply pipe 56 of the high-pressure ultrapure water apparatus used in Example 1 was changed from SUS316 pipe to PTFE pipe to produce high-pressure ultrapure water, and the produced high-pressure ultrapure water was produced. The number of fine particles contained in pure water was measured.

(Embodiment 3) As the valve spring 22 of the discharge side check valves 52a and 52b of the high-pressure ultrapure water system used in Embodiment 2, the spring constant is 0.50 kgf / cm to 0.25.
High-pressure ultrapure water was produced by using the one reduced to kgf / cm, and the number of fine particles contained in the produced high-pressure ultrapure water was measured.

(Embodiment 4) The discharge-side check valve 52 on one pressure transmitting portion 30a side of the high-pressure ultrapure water apparatus used in Embodiment 3
As a, the valve element 16 and the valve rod 20 shown in FIGS.
A high-pressure ultrapure water was produced using a check valve made of PVDF, and the number of fine particles contained in the high-pressure ultrapure water produced on the pressure transmitting portion 30a side was measured. It should be noted that when the check valve having the valve body 16 and the valve rod 20 made of PVDF as shown in FIGS. 5 and 6 is used as the discharge side check valve 52a on the other pressure transmitting portion 30b side, high pressure ultrapure water is obtained. It is considered that the number of fine particles contained in is further reduced.

(Embodiment 5) As the discharge-side check valves 52a and 52b of the high-pressure ultrapure water apparatus used in Embodiment 4, all the liquid contact parts with ultrapure water shown in FIG. High-pressure ultrapure water was produced using a stop valve, and the number of fine particles contained in the produced high-pressure ultrapure water was measured.

(Embodiment 6) The suction side check valves 50a and 50b and the discharge side check valves 52a and 52b of the high pressure ultrapure water system used in Example 5 are connected to ultrapure water as shown in FIG. A non-return valve in which all liquid parts are made of PVDF is used, and further, with the ultrapure water (high pressure ultrapure water) in the flow path on the upstream side of the suction side check valve 50a and the downstream side of the discharge side check valve 50b All wetted parts are ETFE
High-pressure ultrapure water was produced using the high-pressure ultrapure water production apparatus lined in FIG. 8 and the number of fine particles contained in the produced high-pressure ultrapure water was measured.

(Comparative Example) As the discharge side check valves 52a and 52b of the high-pressure ultrapure water system used in Example 1, high-pressure ultrapure water was manufactured by using the check valves shown in FIG. The number of fine particles contained in the high-pressure ultrapure water was measured.

The measurement results of Examples 1 to 6 and Comparative Example are shown in Table 1 below. It should be noted that the number of fine particles contained in ultrapure water at normal pressure is shown for reference.

[Table 1]

According to the first embodiment of Table 1, the check valve shown in FIG. 9 which has been widely used in the past is used for the suction side check valve of the high pressure ultrapure water producing system shown in FIG. When pure water is produced, as shown in a comparative example, in the produced high-pressure ultrapure water, there are thousands of times as many fine particles as the normal pressure ultrapure water. It can be seen that when high-pressure ultrapure water is manufactured using the check valve shown in FIG. 4, the number of fine particles present in this high-pressure ultrapure water can be significantly reduced.

According to the second embodiment, the high-pressure ultrapure water supply pipe 56 of the high-pressure ultrapure water system is changed from SUS316 pipe to PTFE pipe to produce high-pressure ultrapure water.
It can be seen that the improvement can be made for fine particles having a particle size of m or more.

According to the third embodiment, the discharge side check valves 52a, 5a
2b valve spring 22 has a spring constant of 0.50 kg
It can be seen that the number of fine particles in the ultrapure water can also be reduced by increasing the opening / closing stroke amount of the check valve by using the one reduced from f / cm to 0.25 kgf / cm.

According to the fourth embodiment, the discharge side check valves 52a, 5a
2b is a valve body 16 and a valve rod 2 shown in FIGS.
It can be seen that the number of fine particles in ultrapure water can be reduced by using a check valve in which 0 is made of PVDF.

According to the fifth embodiment, the discharge-side check valves 52a, 5a, 5
As 2b, all the parts in contact with the ultrapure water shown in FIG. 7 are PV.
It can be seen that the number of fine particles can be slightly reduced by using the check valve made of DF. From this measurement result, there was almost no improvement in the number of fine particles in the ultrapure water, because the Teflon bellows in the pressure transmission part was broken and replaced, so the fine particles eluted in the ultrapure water were saturated. It is thought that it is because they have not done it. Therefore, it is considered that this data should be treated as provisional.

According to the sixth embodiment, the high-pressure ultrapure water producing apparatus shown in FIG. 8 can produce high-pressure ultrapure water in which fine particles having a level almost equal to that of normal-pressure ultrapure water are produced. It turns out that water can be used for washing and the like.

[0063]

As described above, according to the present invention,
It is possible to manufacture high-pressure ultrapure water in which the number of fine particles contained in the liquid is reduced to several times to several tens of times or less that of the fine particles contained in normal pressure ultrapure water. It becomes possible to clean only with ultra pure water.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an outline of a high-pressure ultrapure water production system according to an embodiment of the present invention.

FIG. 2 is a diagram showing the first half of a flowchart for explaining the operation of the high-pressure ultrapure water production system shown in FIG.

FIG. 3 is a diagram showing the latter half of the flowchart for explaining the operation of the high-pressure ultrapure water production system shown in FIG. 1.

FIG. 4 is a vertical sectional front view showing the suction side check valve shown in FIG. 1.

FIG. 5 is a vertical cross-sectional front view showing another example of a check valve that is optimal for use in the suction side check valve shown in FIG.

6 is a cross-sectional view of the valve body and valve rod of FIG.

FIG. 7 is a vertical cross-sectional front view showing still another example of a check valve which is optimal for use in the suction side check valve shown in FIG. 1.

FIG. 8 is a main part schematic diagram showing a main part of a high-pressure ultrapure water production system according to another embodiment of the present invention.

FIG. 9 is a vertical cross-sectional front view showing a conventional general check valve.

[Explanation of symbols]

12, 100 Valve block 14, 102 Valve seat 14b, 102a Tapered surface 16, 108 Valve body 16b, 108a Tapered surface 18, 106 Guide 20, 110 Valve rod 22 Valve spring 30a, 30b Pressure transmission part 34a, 34b Pressure vessel 36a, 36b Bellows 38a, 38b Ultrapure water chambers 40a, 40b Working fluid chamber 42 Ultrapure water purification device 44 Ultrapure water discharge pipes 46a, 46b Ultrapure water supply pipes 48a, 48b High pressure ultrapure water discharge pipes 50a, 50b Intake side reverse Stop valve 52a, 52b Discharge side check valve 56 High-pressure ultrapure water supply pipe 58 Cleaning container 60 High-pressure pump 62a, 62b City water supply pipe 64 Discharge pump 66a, 66b City water discharge pipe 68a, 68b Intake drive valve 70a, 70b Discharge drive valves 74a, 74b Gauge rod 90 Metal core rods 92a, 92b Cover 94 Welding portion 104 Guide retainer 14,116,118,120 block 114a, 116a, 118a, 120a lining portion

Continued front page    (72) Inventor Mitsuhiko Shiragashi             11-1 Haneda Asahi-cho, Ota-ku, Tokyo Co., Ltd.             Inside the EBARA CORPORATION (72) Inventor Itsuki Takahata             11-1 Haneda Asahi-cho, Ota-ku, Tokyo Co., Ltd.             Inside the EBARA CORPORATION (72) Inventor Takayuki Saito             4-2-1 Honfujisawa, Fujisawa City, Kanagawa Prefecture             Inside the EBARA Research Institute (72) Inventor Yasushi Toma             4-2-1 Honfujisawa, Fujisawa City, Kanagawa Prefecture             Inside the EBARA Research Institute F term (reference) 3H071 AA01 CC41 DD12 DD13 DD14                       EE07

Claims (8)

[Claims] 1. Ultrapure water purified by an ultrapure water purification device,
A pressure transmission part for transmitting the pressure of the liquid pressurized by the high-pressure pump, a suction-side check valve interposed in the ultrapure water supply pipe for supplying ultrapure water into the pressure transmission part, and the pressure transmission part A high pressure ultrapure water discharge pipe for discharging pressurized ultrapure water is provided with a discharge side check valve, and the discharge side check valve whose valve body makes surface contact with the valve seat is used. At the same time, at least one of the valve body and the valve seat is made of a polymer material. 2. The ultrapure water purified by the ultrapure water purification device,
A pressure transmission part for transmitting the pressure of the liquid pressurized by the high-pressure pump, a suction-side check valve interposed in the ultrapure water supply pipe for supplying ultrapure water into the pressure transmission part, and the pressure transmission part A high-pressure ultrapure water discharge pipe for discharging pressurized ultrapure water is provided with a discharge-side check valve, and the suction-side check valve whose valve body makes surface contact with the valve seat is used. At the same time, at least one of the valve body and the valve seat is made of a polymer material. 3. At least one of the valve rod or the guide of a guide for guiding the valve rod by sliding with a valve rod connected to the valve body of the discharge side check valve and / or the suction side check valve. 3. The high-pressure ultrapure water production system according to claim 1 or 2, wherein is made of a polymer material. 4. The ultrapure water purified by the ultrapure water purification device,
A plurality of pressure transmission parts for transmitting the pressure of the liquid pressurized by a high-pressure pump; suction-side check valves respectively inserted in ultrapure water supply pipes for supplying ultrapure water into the pressure transmission parts; A high pressure ultrapure water discharge pipe for discharging the ultrapure water pressurized in each pressure transmission part is provided with a discharge-side check valve, and the ultrapure water discharged from one of the pressure transmission parts With pressure,
A high-pressure ultrapure water production system characterized in that the suction-side check valve and / or the discharge-side check valve provided on the other side of the pressure transmitting portion are closed. 5. The suction side check valve and / or the discharge side check valve, wherein a valve body is in surface contact with a valve seat, and at least one of the valve body and the valve seat is a polymer material. The high-pressure ultrapure water production system according to claim 4, characterized in that it is manufactured. 6. The ultrapure water purified by the ultrapure water purification device,
A pressure transmission part for transmitting the pressure of the liquid pressurized by the high-pressure pump, a suction-side check valve interposed in the ultrapure water supply pipe for supplying ultrapure water into the pressure transmission part, and the pressure transmission part A high pressure ultrapure water discharge pipe for discharging pressurized ultrapure water, and a discharge-side check valve interposed between the pressure transmission section and the ultrapure water; and a suction-side check valve. A high-pressure ultrapure water production system characterized in that a portion of the pipe located downstream of the valve and upstream of the discharge-side check valve in contact with ultrapure water is made of a polymer material. 7. The high pressure ultrapure water production system according to claim 6, wherein the liquid contact portion of the pipe located downstream of the discharge side check valve is made of a polymer material. 8. The high-pressure ultrapure water production system according to claim 1, wherein the polymer material is fluororesin or polyetheretherketone.