JP3373234B2 - Filtration vessel with pipe fitting - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filtering device used in a semiconductor manufacturing process and the like, and a container and a pipe joint used therein.

[0002]

2. Description of the Related Art The filtering device of the present invention is preferably used particularly in a semiconductor manufacturing process. However, in semiconductor manufacturing, in order to improve the yield, there are severe conditions against dust generation of the filtering device itself. Is imposed. Therefore, it is desired to improve the pipe joint, the container, the material of the filter cartridge, etc., which constitutes the filtration device, and the processing accuracy.
Various problems remain with the joints.

That is, a small gap, that is, a fluid retention portion is likely to be formed in a joint having many joints, and when a fluid containing chemicals is flowed, the liquid accumulates in the fluid and deteriorates to generate dust. There is a problem in that the dust adheres to the product and reduces the yield.

Therefore, various improvements and improvements have been made to the pipe joints from the past, but none of them could sufficiently satisfy the above-mentioned conditions required in the semiconductor industry. For example, the most commonly used conventional method is to wrap fluorocarbon resin sealing tape to completely seal the connection port of the container and the fitting body, or to use a ferrule to increase the adhesion between the fitting body and the pipe. As described above, there has been a problem that the liquid permeates into the gaps formed in the seal portions and deteriorates to become dust, which has a harmful effect on semiconductor manufacturing.

Also, a method of using an O-ring at the joint between the joint and the container to complete the seal is often used. However, the liquid still penetrates into the gap formed around the O-ring, which causes the same problem as described above. Will occur. Furthermore, there is also a method of directly connecting the pipes to the container by welding etc. to reduce the joints and the gaps, but it is not possible to change the pipes and various types of containers are required according to the process. There is a problem that it costs too much.

[0006] In addition, there have been devised such that the container and the joint body are integrated by integral molding or processing, the joint body alone is welded to allow the pipes to be freely attached and detached, or the seal portions are provided at two or more places. However, all of them are costly methods, and they are not satisfactory in terms of strength and liquid retention.

[0007]

DISCLOSURE OF THE INVENTION The present invention relates to a filtration device used in semiconductor manufacturing or the like, in which a conventional pipe joint having a risk of itself becoming a source of dust is improved, and a filtration container incorporating the same is provided. It is an object of the present invention to provide a filtration device that contributes to the improvement of the semiconductor manufacturing yield by the development.

[0008]

Therefore, the present inventor has conducted research on the structures of the pipe joint and the joint of the container, and as a result,
In order to make the structure as simple as possible with as few joints as possible, the joint structure is incorporated into the container structure, and the distance from the liquid flow in the pipeline to the seal closing curve is shortened and the number of sealing points is reduced to only the primary seal. It was confirmed that the above-mentioned problems could be solved by minimizing the liquid pool and further devising the structure, and completed the present invention.

That is, the present invention is a container for storing a filter.
For a filtration device that consists of
This is a container with a built-in pipe joint,
Tighten the container to the lid or bottom, and to the upper half of the side.
The screw thread that engages with the nut is engraved, and the bottom part
A stepped flat surface is provided for face sealing
The fluid inlet and outlet and the exhaust outlet if necessary
Be sure that the piping with flare is
Have a widened end and the tightening nut is
The upper half of the outer surface of has a tetrahedral shape, and
Is engraved with threads that are screwed into the inlet and outlet and outlet of the container.
It has a cylindrical part that penetrates the pipe and its inner surface.
A cylindrical part that penetrates the end of the expanded pipe
The above-mentioned container and piping are connected with the tightening nut.
To It is done by screwing it into the screw hole of the container of
The edge of the step inside the tightening nut is the end of the pipe.
Bites into the expanded portion of the pipe, and the force is
By transmitting to the contact surface and the contact surface of the bush and the container.
The filtration container with pipe joint and the
And a filtration device using the same and a pipe joint used therefor
It is something that provides a hand.

The filter device of the present invention mainly comprises a filter cartridge, a container, a pipe, a tightening nut, and a bush to be inserted into the pipe. Of these, the filter cartridge is preferably a plastic, for example, a filter cartridge composed of a fluororesin membrane filter and a plastic support member. For example, those commercially available from Japan Millipore Limited are used.

The container is for sealing and fixing both the inlet of the fluid to be filtered, the outlet of the filtered fluid, a lid provided with an exhaust port for venting if necessary, a pot for accommodating the filter cartridge fitted therein and a pot. And a lid member. The pot, the external lid portion, and the lid member of this container are preferably made of metal such as stainless steel, and the inner surface of the pot and the interior of the lid are preferably made of plastic such as fluorine resin, styrene resin, and olefin resin. Tetrafluoroethylene (PTFE), or a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether (PF
A) is particularly preferred. In addition, the structure of the container will be described in detail with reference to the drawings in an embodiment described later together with the joint.

The pipe joint is composed of a pipe having a flared bush press-fitted at the end and a diameter enlarged at the end, and a tightening nut, and is made of a plastic such as a fluororesin, a polyolefin resin, or a polystyrene resin. ing. The details of the structure will be described in detail in Examples.

The fluid to be filtered using the filter of the present invention is not particularly limited, but suitable target liquids include pure water used in the semiconductor manufacturing process, solutions in which chemicals are dissolved, organic solvents and the like.

[0014]

In order to achieve the object of the present invention, a special joint which realizes a good connection between the filter container and the pipe is required. That is, it is strong, has a perfect seal, does not leak under various temperature and pressure conditions, is easy to combine and separate, can be used repeatedly, and has no liquid pool that causes dust. A joint (structure) is necessary.

Therefore, in the present invention, a joint having a structure in which a part of the joint structure is incorporated in the lid portion of the container is adopted in order to reduce the joint portion as much as possible to enhance the strength, the ease of joint separation and the easy workability. did. That is, a structure in which a pipe is fixed by directly providing a screw hole in the fluid inlet / outlet and the exhaust port of the container lid and screwing a tightening nut into the screw hole is adopted. For this reason, the protruding portion of the joint to the outside of the container is reduced, the risk of breakage is reduced, and the strength is also improved.
In addition, a parallel cylindrical portion into which the end of the bush is inserted is provided in the hole of the container lid, and the contact surface between the bush and the container lid is kept vertical to prevent bias of force and tightening nut. Prevents malfunctions when tightening the screw part of and the screw part of the container lid. Further, at the time of normal connection, a slight gap is formed in the lower end direction of the tightening nut so that the tightening nut can be further tightened.

Next, regarding the seal mechanism for preventing leakage and liquid pool generation, the seal of the present invention uses only the primary seal in order to minimize the liquid pool, and the secondary and tertiary high order seals are not provided. I chose The specific seal is a face seal (B in FIG. 1) at the abutting portion provided at the joint between the bush and the fluid inlet / outlet of the container lid, and an edge seal (A in FIG. 1) at the contact portion between the pipe and the bush. ). In these seals, when a tightening nut is screwed into the connecting portion of the container, the edge portion on the inner surface of the nut bites into the outer surface of the pipe (A in FIG. 1), and the force is applied to the contact surface between the pipe and the bush and Is transmitted to the contact surface of the bush end surface of the container and the abutting portion of the container coupling portion, and both surfaces are tightly sealed.

In the above-mentioned edge seal, since the pipe end has a flared bush (Fig. 5 ) press-fitted to expand the pipe diameter, the edge on the inner surface of the tightening nut bites into it and becomes strong. It is pressed to complete the seal.
At the same time, the pipe is prevented from coming off. Further, in the face seal of the present invention, the distance from the seal closed curve, which is the boundary between the liquid-contacting portion and the non-liquid-contacting portion, to the fluid in the pipe is the shortest, so that liquid pooling is prevented.

Next, the flow of fluid in the filtration device of the present invention will be described. The fluid flows into the container from an inflow port provided in the container lid through a pipe connected by a joint. The fluid that has filled the container fills the gap between the inner wall of the container and the filter cartridge, then enters the filter cartridge, and is filtered by the filter membrane. The filtered fluid collects in the channel provided in the center of the filter cartridge and flows out from the outlet pipe connected by the joint to the external pipe. When the gases entrained in the fluid are accumulated in the container, they vent from the exhaust port to the outside.

[0019]

Embodiments Next, the structures of a filtering device, a container used therein, and a pipe joint will be described with reference to the drawings. Figure 1
FIG. 3 is a cross-sectional view showing the structure of a pipe joint used in the present invention.
In the figure, 1 is a container in which the joint is connected and a filter cartridge is housed, 1-1 is its inner surface, 1-2
Indicates the outer surface. Reference numeral 2 is a pipe, and a bush 4 is press-fitted into the end of the pipe 4 by using a jig that has been developed separately. By inserting this bush, the diameter of the end portion is enlarged. Its form is as shown in FIG. Further, the bushing has the shape of as shown in FIG.

Reference numeral 3 is a tightening nut, and FIG. 7 is a perspective view thereof. A screw thread is provided on the lower half of the outer surface of the nut so that the nut can be screwed into the container connecting portion. Further, about the upper half thereof is formed into a substantially tetrahedral shape so that the additional tightening can be easily performed. The inner surface of the nut is formed in a cylindrical shape having two stages, that is, a cylindrical portion through which the pipe can freely pass and a cylindrical portion through which a bush is inserted and which is enlarged can loosely penetrate. The stepped portion acts on the edge seal A in FIG.

Next, the manner of connecting the above-mentioned container and pipe joints will be described. As shown in FIG. 1, the joint portions provided at the fluid inlet and outlet of the container are threaded so that the outer periphery can be screwed with the tightening nut. And a tapered pipe fitting portion 1-4 that fits with the enlarged pipe end,
And a parallel cylindrical bush fitting portion 1 that fits with the bush
-5 and.

A tightening nut, which is inserted through a pipe having a bush press-fitted at its end, is screwed into the container connecting portion. By tightening the nut, the edge of the stepped portion on the inner surface of the nut bites into the outer surface of the enlarged pipe (A), and its force is applied to the contact surface between the pipe and the bush, and further to the contact surface between the bush end surface and the container (B). The container and the pipe are firmly connected to each other by being transmitted, and a seal is made. That is, the seal is completely completed by the edge seal between the edge of the stepped portion on the inner surface of the tightening nut of FIG. 1A and the enlarged piping portion and the surface seal between the container of B and the end surface of the bush.

FIG. 2 is a sectional view showing an example of the container. In the figure, 1-6 is a container lid part, 1-7 is a container pot part, 5-1.
Is a disk filter cartridge, 1-8 is an inlet,
1-9 is an outflow port and 1-10 is an exhaust port. Note that FIG.
In the container, the lid and the pot are fixed to each other by the bolts on the flange portion. For example, as shown in FIG. 3, a method using a detachable metal band-shaped fastener is used as a method for fixing the two. Can be taken. Note that 1- in FIG.
Reference numerals 6 to 1-10 have the same meanings as in FIG. 2, and reference numeral 1-11 is a crank band (closing device).

The filter cartridge is a disc filter cartridge (5-1) in which 10 to 20 discs each having a fluororesin membrane filter supported by a plastic support member are stacked and an outflow hole is provided in the center, or a pleat as shown in FIG. Filter cartridge (5-2)
Alternatively, a hollow fiber cartridge or the like is used.

[0025]

EFFECTS OF THE INVENTION The filtration device of the present invention has a simple structure in which the pipe joint incorporated in the container, which is the main part, has fewer joints than the conventional joints, and almost no liquid pool can be formed, and a seal is provided. It has the effect of being completely done. In addition, the pipe connection operation is convenient because it is only necessary to tighten the tightening nut and retighten it if necessary, and there are few mistaken operations and the effect that it can be used repeatedly, and it is easy and economical to process. There is also an effect that the joint portion is compact and has high strength against external force.

[Brief description of drawings]

FIG. 1 is a sectional view showing the structure of a pipe joint incorporated in a container used in the present invention.

FIG. 2 is a sectional view showing an example of a container accommodating the filter cartridge of the present invention.

FIG. 3 is a cross-sectional view showing another example of the container.

FIG. 4 is a plan view showing an example of a clamp band.

FIG. 5 is a perspective view of a bush.

FIG. 6 is a partial plan view of a pipe in which a flared bush is press-fitted into an end portion.

FIG. 7 is a perspective view of a tightening nut.

[Explanation of symbols]

1 container 1-1 Inner surface of container 1-2 Container outer surface 1-3 Container screw part 1-4 Tapered expansion pipe fitting part of container 1-5 Container bushing fitting part (parallel cylindrical part) 1-6 Container lid part 1-7 Container pot part 1-8 Inlet 1-9 Outlet 1-10 Exhaust port 1-11 Clamp band (closure tool) 2 piping 3 Tightening nut 3-1 Tightening nut screw part 4 bush 5-1 Disc filter cartridge 5-2 Pleated filter cartridge A Edge seal B side seal

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Claims (7)

(57) [Claims] 1. A container for storing a filter, a pipe, and a tightening nut.
Built-in pipe joint for filtration equipment consisting of
A container, The filter storage container has a lid or bottom
A screw thread that engages with the tightening nut is engraved on the upper half of the side surface.
And the bottom surface of the bush is face-sealed.
Fluid inlets and outlets with stepped planes for
And that an exhaust port is provided if necessary, The pipe has a flared bush press-fitted to expand the diameter of the end.
Having The upper half of the outer surface of the tightening nut has a tetrahedral shape.
In addition, the lower part of the container has an inflow port and an exhaust port of the container.
Threads to be screwed are engraved, and the inner surface of the thread penetrates the pipe.
Cylinder to be installed and a cylinder to penetrate the end of the expanded pipe under it
That the parts are provided in steps, To connect the above-mentioned container and piping, use the tightening nut In a container
It is made by screwing it into the screw hole, and sealing is done by the tightening nut.
Expansion on the edge of the inner surface of the pipe where the stepped edge is at the end of the pipe
Bites into the pipe, and the force is applied to the contact surface between the pipe and bush and the bush.
It is done by transmitting to the contact surface of the container
thing, A filtration container with a pipe joint characterized by: 2. The filtration container with a pipe joint according to claim 1, wherein the material of the portion in contact with the fluid is resin. 3. The filtration container with a pipe joint according to claim 2, wherein the resin is a fluororesin. 4. A filtration device for semiconductor manufacturing, wherein a filter cartridge is housed in the filtration container with a pipe joint according to claim 1. 5. The filtration device according to claim 4, wherein the filter cartridge is a stack of disk filters in which a resin membrane filter is supported by a plastic support, or a pleated filter or hollow fiber filter cartridge. 6. A tightening method wherein a screw thread for directly screwing into a container is provided on a substantially lower half of an outer surface, and a tetrahedron shape for tightening is formed on the screw thread, and a stepped cylindrical shape having an edge on an inner surface is provided. A pipe joint to be incorporated in a container for a filtering device, which comprises a nut with a flare and a pipe having a diameter-increased end portion into which a bush with a flare is pressed. 7. The pipe joint according to claim 6, wherein the material is a fluororesin.