JP4666626B2 - Backfire back pressure prevention device - Google Patents

Description

  The present invention relates to a backfire back pressure prevention device for preventing damage to upstream equipment from a flame and explosion pressure even when a combustible fluid burns and explodes on the downstream side.

  When conducting tests with the possibility of fire and explosion in a closed test chamber, it is necessary to prevent damage to equipment located upstream from the combustion flame and explosion pressure during the explosion.

  Patent documents 1 to 3 have already been proposed as devices for protecting equipment from such a flame and explosion pressure.

  The apparatus of Patent Document 1 is an explosion load reduction valve that is attached to a closed chamber, for example, a crankcase of a combustion engine, and reduces the load at the time of an explosion. As shown in FIG. It consists of a valve seat 51 that can be inserted into the wall 53, a spring-loaded closing plate 54, and a flame barrier 59. When the pressure in the protected room rises, the closing plate 54 opens to release the pressure to the outside. The flame to be passed is extinguished by the flame barrier 59.

  The device of Patent Document 2 is a fluid on-off valve structure that prevents backflow and flow of fluid (gas) discharged from a compressor, for example, and as shown in FIG. A movable valve 64 is provided on one end side of the reduced diameter pipe portion 62 so as to be movable in the flow pipe, and the movable valve 64 is brought into contact with the reduced diameter pipe portion 62 at the time of backflow to prevent backflow of fluid. Is.

  As shown in FIG. 5, the dry backfire preventer of Patent Document 3 includes a check valve body 77 that opens in a fuel gas passage formed in a main body casing 71 with a normal flow pressure of fuel gas, A shut-off valve body 73 that operates in the event of a fire and shuts off the fuel gas passage is disposed, and a flame extinguishing tool 76 is disposed on the downstream side of the location where the shut-off valve body 73 is disposed.

Japanese Patent No. 3288663, “Explosion Load Reduction Valve” JP-A-8-21547, “Fluid Open / Close Valve Structure” Japanese Unexamined Patent Publication No. 2000-240899, “Dry-type backfire preventer”

  As described above, when a test with a possibility of fire and explosion is performed in a sealed test chamber, it is necessary to prevent damage to equipment located upstream from the combustion flame and the explosion pressure at the time of the explosion.

  However, the above-described device of Patent Document 1 needs to be attached to a closed chamber, for example, a test chamber for a combustion test. In this case, the pressure increase in the test chamber and the propagation of flame to the outside can be prevented, but there is a problem that the propagation of the flame and explosion pressure to the upstream equipment (for example, the air supply device) communicating with the test chamber cannot be prevented. .

  The device of Patent Document 2 is installed between the upstream device and the test room and can be operated by the explosion pressure at the time of explosion to prevent backflow. However, the backflow of flame until the flow path is completely closed.・ There was a problem that backfire could not be prevented.

  Furthermore, the dry backfire preventer of Patent Document 3 can be installed between the upstream equipment and the test room to prevent backfire of the flame during combustion and backflow due to the explosion pressure at the time of the explosion. There have been problems such as damage caused by exposure to pressure, large pressure loss during steady operation, complicated and large equipment, and limited installation space.

  The present invention has been developed to solve the above-described problems. That is, the object of the present invention is to protect the upstream equipment by preventing the backflow and backfire of the combustion flame to the upstream side and the propagation of the explosion pressure at the time of the explosion even if a fire and explosion occur on the downstream side. To provide a backfire back pressure prevention device that can be damaged by exposure to explosion pressure, has little pressure loss during steady operation, is simple and small in size, and has few installation space restrictions. is there.

In order to achieve the above object, according to the present invention, when the fuel burns and explodes on the downstream side, the backfire backpressure prevention device prevents the backflow / backfire of the flame and the propagation of the explosion pressure to the upstream side. Because
A hollow tube that communicates the upstream side and the downstream side, a closing plate that can be opened and closed at the outlet end of the hollow tube, and urging the closing plate to the downstream side during steady operation An urging means for holding, and a frame arrester installed by closing the flow path in the hollow tube,
There is provided a backfire back pressure prevention device characterized in that when the pressure at the time of explosion exceeds the urging force of the urging means, the closing plate is pressed against the opening end to close the opening.

  According to a preferred embodiment of the present invention, the frame arrester has a crimp ribbon type frame arrester element, and the frame arrester element has an opening having a flame extinguishing diameter or less.

The hollow tube has an axial center extending vertically from the upstream side to the downstream side,
The closing plate is a flat plate member capable of closing the upper end of the hollow tube,
The urging means is a compression spring sandwiched between a fixed portion in a hollow tube and a closing plate,
The biasing force of the compression spring is set to be the same as or slightly larger than the weight of the closing plate in the open position of the closing plate.

According to another preferred embodiment, the hollow tube has an axial center extending horizontally from the upstream side to the downstream side,
The closing plate is a flat member capable of closing the vertical opening end of the hollow tube,
The urging means is a compression spring sandwiched between a fixed portion in a hollow tube and a closing plate,
The biasing force of the compression spring is set to be the same as or slightly larger than the sliding resistance of the closing plate in the open position of the closing plate.

The closure plate has at least one through hole;
Furthermore, it is preferable that one end portion is fixed in the hollow tube through the through hole, and a guide rod having a presser capable of adjusting the height position of the closing plate larger than the through hole is provided at the other end portion.

  According to the configuration of the present invention, since the flame arrester is installed by closing the flow path in the hollow tube communicating with the upstream side and the downstream side, even when the fuel burns on the downstream side, the reverse flow / backfire of the flame Can be prevented by the flame extinguishing function of the flame arrestor.

  Also, when the pressure at the time of explosion exceeds the urging force of the urging means, the closing plate is pressed against the opening end to close the opening, so even if the fuel explodes downstream, by closing the opening, Propagation of explosion pressure can be prevented at the same time as the backflow and backfire of flame.

  Furthermore, since the closing plate is held in the open position during steady operation by the urging means, the pressure loss during steady operation can be reduced.

  Further, when the closing plate closes the opening, only a simple structure closing plate is exposed to the explosion pressure, so that there are few parts to be damaged.

Further, since the frame arrester is installed in the hollow tube and the closing plate is installed at the opening end on the outlet side of the hollow tube, the apparatus can be simplified and miniaturized, and the installation space can be almost eliminated.
In particular, since the integrated structure is relatively simple, if a frame arrester of a corresponding size is used, it can be installed in a wide range of piping.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

FIG. 1 is an overall configuration diagram of a backfire backpressure prevention device of the present invention. The backfire backpressure prevention device 10 of the present invention is a backfire backpressure prevention device that prevents backflow / backfire of flames and propagation of explosion pressure to the upstream side when fuel burns and explodes on the downstream side. .
In this figure, the backfire back pressure prevention device 10 of the present invention has a hollow tube 12, a closing plate 14, a guide rod 16, a biasing means 18 and a frame arrester 20.

The hollow tube 12 is fixed to a partition wall 11 (for example, a floor member of a combustion test chamber) that partitions the upstream side and the downstream side by a flange or the like, and communicates the upstream side and the downstream side through the inside. The upstream side is, for example, the upper part of the combustion test chamber, and the downstream side is, for example, under the floor of the combustion test chamber.
In this example, the hollow tube 12 has an axial center extending vertically from the upstream side to the downstream side, and has a horizontal opening end 12a at the upper end thereof.

The closing plate 14 is provided at the outlet side opening end 12a of the hollow tube 12 so as to be opened and closed.
In this example, the closing plate 14 is a flat plate-like member capable of closing the upper end of the hollow tube 12, and has a through hole 14a at the center thereof.

  The guide rod 16 has an intermediate portion 16b slightly narrower than the through hole 14a extending vertically through the through hole 14a, and its lower end portion 16a is fixed to the upper portion of the frame arrester in this example in the hollow tube, and is closed to the upper end portion larger than the through hole. There is a presser 16c that can adjust the height position of the plate.

With this configuration, the through hole 14a of the closing plate 14 is guided by the outer peripheral surface of the intermediate portion 16b of the guide rod 16 so as to be movable up and down, and the closing plate 14 is not moved above its raised position (open position) by the presser 16c. Can be locked.
In order to smoothly guide the vertical movement of the closing plate 14 at the intermediate portion 16b, a hollow cylindrical member (not shown) having an inner surface with the same diameter as the through hole 14a of the closing plate 14 is used as the through hole 14a of the closing plate 14. It may be fixed adjacent to.

The urging means 18 urges the closing plate 14 to the downstream side during steady operation and holds it in the open position.
In this example, the urging means 18 is a compression spring that is sandwiched between the fixing portion in the hollow tube 12 and the closing plate 14. The biasing force of the compression spring 18 is set to be the same as or slightly larger than the weight of the closing plate 14 in the open position of the closing plate 14. Note that the spring constant of the compression spring is preferably set as small as possible to reduce the necessary differential pressure at the closed position of the closing plate 14.
With the above-described configuration, when the pressure at the time of explosion exceeds the urging force of the urging means 18, the closing plate 14 is pressed against the opening end to close the opening.

The frame arrester 20 is installed in the hollow tube 12 with the flow path closed.
In this example, the frame arrester 20 includes a crimp ribbon type frame arrester element 20a. The frame arrester element 20a has an opening having a diameter equal to or smaller than the flame extinguishing diameter, and the entire amount of gas flowing through the hollow tube 12 passes through the opening.
The flame arrester element 20a is set to have a sufficiently small pressure loss during steady operation.

FIG. 2 is an explanatory view of the operation of the backfire back pressure prevention device of the present invention. In this figure, (A) shows a steady operation, and (B) shows an explosion.
With the configuration described above, during the steady operation of (A), the closing plate 14 is urged downstream by the urging means 18 and held in the open position. Therefore, the pressure loss of the fluid (for example, air) flowing from the upstream side to the downstream side is only the pressure loss due to the frame arrester 20 and is set sufficiently small.
In the explosion of (B), if an explosion occurs on the downstream side and the pressure on the downstream side rises during the explosion, this pressure exceeds the urging force of the urging means 18 (in this example, the force pushing the closing plate 14 upward). When this occurs, the closing plate 14 is pressed against the opening end of the hollow tube 12 by this pressure to close the opening, thereby preventing the explosion pressure from propagating from the downstream side to the upstream side.
In addition, when only a fire has occurred on the downstream side, there is a possibility that the flame flows into the hollow tube 12 with the closing plate 14 open, but the flame arrester element 20a is less than the extinguishing diameter. Since it has an opening, the flame cannot pass through this opening and is extinguished here.

Therefore, the backfire back pressure prevention device 10 of the present invention has a function of blocking the flow path because no abnormal pressure is applied to the upstream equipment when the abnormal pressure rises on the downstream side.
This device is installed inside an air supply opening such as a fire test room. The blocking method of the flow path is the same as that of a check valve, etc., and normally the valve body is pushed up by the force of the spring to secure the air flow path, but when the external pressure is applied, the valve body is pushed down to shut off the flow path .

The present invention is not limited to the above-described embodiments. For example, the hollow tube 12 is a horizontal tube whose axis extends horizontally from the upstream side to the downstream side, and the closing plate 14 is a vertical opening end of the hollow tube. The closing member may be a flat plate member, and the urging force of the urging means 18 may be set to be the same as or slightly larger than the sliding resistance of the closing plate in the open position of the closing plate.
Further, the axial center of the hollow tube 12 may be inclined, and the urging force of the urging means 18 may be set equal to or slightly larger than the sliding resistance of the closing plate at the opening position of the closing plate.

  According to the configuration of the present invention described above, the flame arrester 20 is installed in the hollow tube 12 communicating with the upstream side and the downstream side so as to close the flow path, so that even when the fuel burns on the downstream side, the flame Can be prevented by the flame extinguishing function of the flame arrestor 20.

  Further, when the pressure at the time of explosion exceeds the urging force of the urging means 18, the closing plate 14 is pressed against the opening end to close the opening, so that even when the fuel explodes downstream, the opening is closed. Thus, the propagation of explosion pressure can be prevented simultaneously with the backflow and backfire of the flame.

Furthermore, the urging means 18 holds the closing plate in the open position during steady operation, so that the pressure loss during steady operation can be reduced.
Further, when the closing plate 14 closes the opening, only the simple structure of the closing plate is exposed to the explosion pressure, so that there are few parts to be damaged.

  Further, since the frame arrester 20 is installed in the hollow tube 12 and the closing plate 14 is installed at the opening end on the outlet side of the hollow tube, the apparatus can be made simple and small, and there is almost no restriction on the installation space. Can do.

  In particular, since the integrated structure is relatively simple, if a frame arrester of a corresponding size is used, it can be installed in a wide range of piping.

  In addition, this invention is not limited to embodiment mentioned above, Of course, it can change variously in the range which does not deviate from the summary of this invention.

It is a whole block diagram of the backfire backpressure prevention apparatus of this invention. It is operation | movement explanatory drawing of the backfire backpressure prevention apparatus of this invention. 2 is a configuration diagram of an apparatus disclosed in Patent Document 1. FIG. It is a block diagram of the apparatus of patent document 2. FIG. It is a block diagram of the apparatus of patent document 3. FIG.

Explanation of symbols

10 Backfire back pressure prevention device, 11 Bulkhead,
12 hollow tube, 12a open end,
14 closing plate, 14a through hole,
16 guide rod, 16a lower end,
16b Intermediate part, 16c Presser foot,
18 Biasing means (compression spring),
20 flame arrestor,
20a Frame arrester element

Claims (5)

When a flammable fluid burns and explodes on the downstream side, it is a backfire backpressure prevention device that prevents the backflow / backfire and propagation of explosion pressure to the upstream side,
A hollow tube that communicates the upstream side and the downstream side, a closing plate that can be opened and closed at the outlet end of the hollow tube, and urging the closing plate to the downstream side during steady operation An urging means for holding, and a frame arrester installed by closing the flow path in the hollow tube,
A backfire back pressure prevention device, characterized in that when the pressure at the time of explosion exceeds the urging force of the urging means, the closing plate is pressed against the opening end to close the opening.   2. The backfire back pressure prevention device according to claim 1, wherein the frame arrester has a crimp ribbon type frame arrester element, and the frame arrester element has an opening having a diameter not larger than a flame extinguishing diameter. The hollow tube has an axial center extending vertically from the upstream side to the downstream side,
The closing plate is a flat plate member capable of closing the upper end of the hollow tube,
The urging means is a compression spring sandwiched between a fixed portion in a hollow tube and a closing plate,
2. The backfire back pressure prevention device according to claim 1, wherein an urging force of the compression spring is set to be equal to or slightly larger than a weight of the closing plate in an open position of the closing plate. The hollow tube has an axial center extending horizontally from the upstream side to the downstream side,
The closing plate is a flat member capable of closing the vertical opening end of the hollow tube,
The urging means is a compression spring sandwiched between a fixed portion in a hollow tube and a closing plate,
2. The backfire back pressure prevention device according to claim 1, wherein an urging force of the compression spring is set to be equal to or slightly larger than a sliding resistance of the closing plate in an open position of the closing plate. The closure plate has at least one through hole;
The guide rod having a presser that is fixed in the hollow tube through the through-hole and that can adjust the height position of the closing plate larger than the through-hole at the other end. Or the backfire back pressure prevention apparatus of 4.

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