JPH0464800A - Fluid supply and feed pipe body - Google Patents

Abstract

PURPOSE:To prevent fluid from staying and keep a predetermined quantity of flow constantly by connecting the forward end of an inner pipe on the downstream side of fluid supply and feed with a fluid outflow passage, and providing a fluid outflow side aperture part in part of the upstream side in the fluid supply and feed direction. CONSTITUTION:A pipe body 10 is composed of a small diameter inner pipe 11 forming a gas introducing passage 11a and an outer pipe 12 forming a gas outflow passage 12a. The passages 11a, 12a formed by the inner and outer pipe 11, 12 are connected with each other at a forward end part 11b on the downstream side of the inner pipe 11 in the gas supply and feed direction, gas introduced into the inner pipe 11 flows into the gas outflow passage 12a on the outer pipe 12 side thorough the forward end part 11b to flow in it to the upstream side inversely to the gas supply and feed direction, and it flows out through an outflow passage 16a in an outflow pipe 16 connected with a gas outflow side aperture part 15 to be extended from the part facing a passage end part. Fluid can thus be sent keeping a predetermined flow constantly without staying.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for disposing a gas in a piping system for gas supply, etc., in a flow path where gas accumulation is likely to occur, so that gas constantly flows within the flow path. The present invention relates to a fluid feeding pipe that can maintain the purity of gas by maintaining the same condition.

[Conventional technology]

For example, it is well known that in order to maintain the purity of the gas fed through the piping in a piping system for gas supply, it is better to eliminate dead space in the flow path of the piping. However, when looking at various gas supply piping systems from a structural perspective, it is often unavoidable to create dead spaces as described above.

In other words, when it comes to the main piping that forms the main passage for supplying gas in the gas supply piping system, in consideration of future piping expansion etc. from the perspective of piping equipment, it is necessary to As shown in FIG. 6, it is desired that a branch pipe 2 for connecting an additional pipe be attached in advance with the distal end thereof closed. In such a piping structure, gas flows sequentially in the main passage in the main piping 1 along the feeding direction, but in the branch pipe 2 for connecting the extension piping mentioned above, the gas flows through the branch passage from the branch part to the blockage part. The inside of the branch passage is a dead space when viewed from the main passage, and it is unavoidable for gas to accumulate in this branch passage.

In addition, for example, in a gas supply system that selectively supplies a small amount of gas from the main piping 1 side to the equipment 3 on the usage side, as shown in FIG. It is common practice to provide a variable minute flow rate adjustment valve 4 or the like for minutely controlling the amount of gas supplied at the inflow part to the device 3. When the valve 4 is in a closed state or the controlled flow rate is small, gas accumulates in this part, and the part becomes a dead space and a path.

[Problem to be solved by the invention]

By the way, in a gas supply system having a dead space portion as described above, there is
In a device having a branch pipe 2 whose tip end is closed, the existence of a dead-end passage within the branch pipe 2 may prevent atmospheric components contained in the passage within the pipe 2 during piping or the portion of the pipe 2. The resulting degassed components flow into the main passage within the main pipe 1, resulting in the disadvantage that even if highly purified gas is supplied, the gas will not be purified for any length of time.

In addition, even in a gas supply system using a variable minute flow rate adjustment valve 4 like the latter, gas accumulation occurs immediately before the valve 4, so when opening the valve 4 to allow a minute flow rate to flow, There is a possibility that the purity of the gas may be impaired, which is a problem in practical use.

Furthermore, in this latter gas supply system, in order to purify the gas to be supplied, the entire gas piping system is evacuated several times, and the gas is filled up to just before the valve 4. However, this gas purification method has the following two drawbacks.

In other words, one of them requires the contradictory act of flowing unpurified gas into a piping system filled with ultra-high vacuum or ultra-high purity gas in order to purify the gas. This has the disadvantage that it may cause contamination.

Another problem is that although clean gas can be supplied immediately after purification, as time passes, the purity of the gas decreases due to degassing from the piping.

In particular, in the gas supply system mentioned above, the generation of moisture from the main pipe 1 is unavoidable to some extent, and in gas supply systems where moisture is a problem, the influence is large, and it is important to avoid such malfunctions. It is hoped that some kind of countermeasure will be taken to eradicate it.

Of course, the problems in this type of fluid supply system may also occur with fluids other than gas, and it is desirable to take some kind of countermeasures in consideration of these points.

[Means to solve the problem]

In order to meet such demands, the fluid feeding pipe according to the present invention has a double pipe structure consisting of an inner pipe for introducing fluid and an outer pipe for fluid outflow that forms a fluid outflow passage outside the inner pipe. The downstream end of the inner pipe in the fluid feeding direction is communicated with the fluid outflow passage formed by the outer pipe, and a fluid outflow side opening is provided in a part of the fluid outflow passage on the upstream side in the fluid feeding direction. It was designed to be provided.

[Effect]

According to the present invention, the fluid introduction passage and the fluid outflow passage are constituted by a double pipe structure including an inner pipe and an outer pipe, and the portion facing the distal end of the inner pipe on the downstream side in the fluid feeding direction is Due to the existence of the fluid outflow passage on the outer tube side that communicates with the inner tube side in this part, it is possible to always circulate the fluid at the required flow rate without stagnation, which has solved the problem of conventional methods. Dead space problems caused by fluid accumulation are eliminated, and as a result, high-purity fluid can be appropriately and reliably fed throughout the fluid delivery system.

〔Example〕

Hereinafter, the present invention will be explained in detail using embodiments shown in the drawings.

FIG. 1 is a conceptual diagram showing an embodiment of a fluid supply pipe according to the present invention. In this embodiment, the present invention is applied to a gas supply system using gas as the supply fluid. Explain the case.

In the figure, what is designated as a whole by the reference numeral 10 is a gas supply pipe body with a double pipe structure that characterizes the present invention, and this pipe body 1
0 is a gas introduction passage 11a that introduces gas from a supply source.
It is composed of a small-diameter inner tube 11 that forms a small diameter inner tube 11, and an outer tube 12 that is fitted on the outside of the inner tube 11 and forms a gas outflow passage 12a on the outside of the inner tube 11. Here, the inner tube 1
The upstream portion in the gas feeding direction in 1 is connected to the inner wall portion of the pipe 14 that has the same diameter as the outer pipe 12 at the enlarged diameter portion 13 and forms a communication passage 14a that communicates with the main passage on the main pipe side. As a result, this portion of the gas outflow passage 12a formed by the outer tube 12 is formed as a terminal portion. The passages 11a and 12a formed by these inner and outer tubes 11 and 12 are in communication with each other at the downstream end portion (llb) of the inner tube 11 in the gas feeding direction.
The gas introduced into the passage 1 flows into the gas outlet passage 12a on the outer tube 12 side via the tip portion 11b, and flows into the passage 1.
2a, the gas flows toward the upstream side in the opposite direction to the gas feeding direction, and is formed by opening into the outer tube 12 facing the end portion of the passage partitioned by the enlarged diameter portion 13 upstream of the inner tube 11. The gas is configured to flow out from the outflow side opening 15, which is located in the air, through an outflow passage 16a in an outflow side piping 16 connected to this part.

Here, the diameter dimensions, length dimensions, etc. of the inner and outer tubes 11 and 12 described above can be freely set as appropriate depending on the conditions of gas flow and gas accumulation in the gas supply system where the tube body 10 is attached. That's a good thing.

The tube body 10 having such a double tube structure according to the present invention,
Fig. 2 shows a case where the application is applied to the branch pipe 2 section for connecting an extension pipe branched from the main pipe 1. By attaching such a pipe body 10, the inside of the branch pipe 2, which has been a problem in the past, can be solved. It becomes possible to eliminate gas accumulation in the dead-end passage and eliminate dead space with respect to the main pipe 1. That is, by attaching the pipe body 10 described above, the branch pipe 2
It is possible to constantly flow a small amount of gas inside the pipe, and as a result, high-purity gas is sequentially fed through the main passage inside the main pipe J.
It becomes possible to supply it to the necessary parts.

Here, in the figure, 17 is a flange portion that connects the tube body 10 to the tip of the branch tube 2, 18 is a flange portion that connects the tube body 10 to the tip of the branch tube 2, and 18 is the tip portion of the tube body 10 on the downstream side in the gas feeding direction of the inner tube 11, and the passage 12a on the outer tube 12 side.
a lid body that is closed with a slight gap in communication with the body, 1
Reference numeral 9 denotes a flow meter installed in the middle of the outflow side pipe 16 through which gas flows out from the gas outflow passage 12, and is connected to the above-mentioned pipe body 10.
The flow meter 19 monitors the amount of gas flowing out by attaching the gas flow meter 19, and is configured to adjust the amount to the required amount. In this case, the amount of gas flowing out by attaching the pipe body 10 according to the present invention can be adjusted by adjusting the diameters of the inner and outer pipes 11, 12, or by adjusting the flow I meter 19. It is adjustable. Note that the gas flowing out through the above-mentioned outflow pipe 16 may be handled by connecting the downstream side to a drain and exhausting it, or by connecting the downstream side of the gas to a drain, or by using the main pipe 1
It goes without saying that it may also be connected to a gas supply source or the like for reflux.

Furthermore, in the above-described configuration, by removing the pipe body 10, it is possible to freely add a new line using the branch pipe 2.

The change in oxygen concentration in nitrogen gas over time in the case where the pipe body 10 of the double pipe structure according to the present invention is attached to the branch pipe 2 for connecting the extension pipe and in the case where the pipe body 10 is a dead-end passage as in the conventional case is compared with the main pipe. Figure 3 shows the results measured downstream of 1. In the conventional case, as is clear from the characteristic indicated by a in the figure, the oxygen concentration decreased slightly over time, and the level is 100PPb, whereas in the case of the present invention, as is clear from the characteristics already shown in the figure, it changes at a level of 1/100 ppd, and the pipe body with the double pipe structure according to the present invention It will be easily understood that by using No. 10, the concentration of impurities in the gas can be suppressed.

FIG. 4 shows that in a gas supply system equipped with a variable minute flow rate adjustment valve 4, when the valve 4 is closed or the flow rate is controlled to an extremely minute level, a gas accumulation occurs immediately before the valve 4. In order to solve the problem of unavoidable contamination of impurities due to degassing from the piping, a pipe body 10 with a double pipe structure, which characterizes the present invention, is provided immediately before the valve 4. It shows the case.

Here, such gas accumulation at valve 4 is actually
E Since this occurs in the inlet side passage facing the valve seat in the valve body, only the tip portion 11b of the inner tube 1 in the tube body 10 according to the present invention is not shown, but it is located in the valve seat in the valve body. A passage 12a formed by the outer tube 12 connected to the outside of the body
It is preferable to use it as a part of the gas flow and create a gas flow similar to the above-mentioned embodiment.

According to such a configuration, it is possible to constantly generate a gas flow in the area in front of the valve seat where gas has conventionally accumulated, and this allows degassing from the piping to be carried away by the gas flow. It is possible to drain it out. Therefore, high-purity gas always flows in just before the valve 4, so that when the valve 4 is opened to supply a minute amount of gas, high-purity gas can always be supplied to the equipment being used. It is something. In particular, in a gas supply system having such a variable minute flow rate adjustment valve 4,
By exposing the tip of the inner tube 11 of the tube body 10 having a double tube structure until just before the valve seat of the valve 4, fresh and highly purified gas can always flow through the seat. Even in a feeding system for distributing a minute amount of gas, the required high purity gas can be appropriately and reliably supplied.

Here, FIG. 5 shows the characteristics when oxygen gas is flowed in an ultra-high vacuum in the case of the present invention using the tube body 10 with such a double tube structure and in the case of a conventional example. There is.

To explain this simply, in this characteristic diagram, the vertical axis is partial pressure and the horizontal axis is time, and this characteristic simultaneously shows oxygen (02), which is the target of the gas flow, and moisture (H2O), which is an impurity. . In the figure, C is the opening time of the valve 4, and d is the oxygen I
The amount of water when flowing at a Torr is the amount of water when the same amount of oxygen is flowing in the conventional case.Before flowing the oxygen gas, Even in high vacuum, trace amounts of oxygen and moisture exist as shown in the figure.

In the conventional method, along with the flow of oxygen, water also flows to 1
It will be easily understood that in contrast to the case where the amount of water increases by more than 0 times, in the case where the present invention is adopted, oxygen gas can be flowed without increasing the amount of water at all.

Therefore, the pipe body 1 having the double pipe structure with the above configuration
According to 0, the gas introduction passage 11a and the gas outflow passage 12
a has a double pipe structure with inner and outer pipes 11 and 12, and the part facing the tip 11b on the downstream side in the gas supply direction of the inner pipe 11 is called the inner pipe 11 side at this part. Due to the existence of the gas outflow passage 12a on the communicating outer tube 12 side, it is possible to always circulate the gas at the required flow rate without causing it to stagnate, thereby eliminating the dead space caused by gas accumulation, which was a problem in the past. eliminate problems,
As a result, high-purity fluid can be appropriately and reliably fed throughout the gas feeding system.

Note that the present invention is not limited to the structure of the embodiment described above, and the shape, structure, etc. of each part of the tube body 10 of the double-pipe structure may be modified and changed as appropriate, and the application points may also be the same as those described above. It goes without saying that the invention is not limited to the examples.

For example, in the embodiment described above, if it is desired to keep a small amount of gas flowing, it is sufficient to reduce the diameter of the inner pipe 11 on the gas introduction side so that only a small amount of gas can flow. In this case, there is no need to provide the valve 4 to throttle the gas amount in the embodiment shown in FIG. Furthermore, in the embodiment shown in FIG. 4, the downstream side of the outflow pipe 16 is connected to the gas supply side via a purification section having various purification materials, so that the gas is refluxed and reused. It may be configured.

〔Effect of the invention〕

As explained above, the fluid feeding pipe according to the present invention has a double pipe structure consisting of an inner pipe for introducing fluid and an outer pipe for fluid outflow that forms a fluid outflow passage outside the inner pipe. The downstream end of the inner tube in the fluid feeding direction is communicated with the fluid outflow passage formed by the outer tube, and a fluid outflow side opening is provided in a part of the fluid outflow passage on the upstream side in the fluid feeding direction. Despite the simple and inexpensive configuration,
The fluid is retained in the part of the inner pipe for fluid introduction facing the downstream end in the fluid feeding direction by the presence of a fluid outflow passage on the outer pipe side that communicates with the inner pipe side at this part. This allows the gas to be distributed at the required flow rate at all times, thereby preventing problems such as impurities entering the gas and impairing its purity, and ensuring that high-purity gas is always supplied. It has excellent effects.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a fluid supply pipe body according to the present invention, FIG. 2 is a schematic configuration diagram when the present invention is applied to a branch pipe section for connecting an extension pipe, and FIG. 3 is a characteristic diagram showing the time change of the oxygen concentration, and FIG. 4 is a schematic configuration diagram when the present invention is installed in the flow path immediately before the variable minute flow rate adjustment valve.
Fig. 5 is a characteristic diagram showing the temporal changes in oxygen partial pressure and moisture partial pressure when oxygen gas is flowing, and Figs. 6 and 7 are schematic diagrams of a gas supply system to explain the conventional structure. . 1... Main piping, 2... Branch pipe, 4... Variable minute flow rate adjustment valve, 10... Pipe body with double pipe structure, 11... Inner pipe, lla... ...Gas introduction passage, 12...Outer tube, 12a...Gas outflow passage, 1
5...Gas outflow side opening, 16...Gas outflow side piping. Patent applicant Nippon Telegraph and Telephone Corporation

Claims (1)

[Claims] It has a double pipe structure consisting of an inner pipe for introducing fluid and an outer pipe for fluid outflow forming a fluid outflow passage outside the inner pipe, and the downstream end of the inner pipe in the fluid feeding direction is connected to the outer pipe. What is claimed is: 1. A fluid feeding pipe body, characterized in that it communicates with a fluid outflow passage formed by a pipe and is provided with a fluid outflow side opening in a part of the upstream side of the fluid outflow passage in the fluid feeding direction.