JPS6210569Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is designed to prevent backfire propagation of flammable gases in the event of backfire by intervening in the supply path of equipment or piping for supplying flammable gases such as acetylene, ethylene, propane gas, city gas, etc. The present invention relates to a dry flashback preventer having a mechanism for blocking and cutting off the supply of flammable gas.

Conventionally, various types of flashback preventers for preventing backfire propagation of flammable gas have been proposed. However,
Conventional dry flashback preventers use a flame extinguisher to extinguish the flames when a flashback occurs, and the rapid pressure rise caused by the explosive pressure closes the shutoff valve and stops the gas supply.

However, in this case, when resetting the dry flashback after the shutoff valve is activated, it is necessary to disassemble the flashback preventer itself or remove the gas outlet hose and the like.

Further, a gas outlet hole is formed in the lower part of the flashback preventer main body, a communication port with the flame extinguishing chamber is provided in a state perpendicular to the gas outlet hole, and a flashback escape port is formed in a straight line with the gas outlet hole. A safety valve is placed at the backfire relief port, and a cutoff valve is provided at the communication port, and the reset rod that opens the communication port resists the spring that biases the cutoff valve to close, and the safety valve holds the cutoff valve in the open state. Some proposals have also been made to keep it in place.

However, in this case, during forward flow, the gas flows into the outer periphery of the flame extinguisher inside the flashback preventer and flows out from the inside of the flame extinguisher to the gas outlet hole. There was a problem in that the check valve provided was located outside the flame extinguisher, making the flashback preventer larger.

The present invention was proposed in view of these points, and includes a flashback prevention chamber formed inside the main body of the flashback prevention device, a valve chamber formed on one side of the center of the flashback prevention chamber, and a valve chamber formed on one side of the center of the flashback prevention chamber. A gas inlet hole is made in the outer end wall of the chamber, a gas communication hole is made in the inner end wall of the chamber, and a gas outlet hole is made in the peripheral wall of the flashback prevention chamber. communicates with the gas outlet hole through the chamber,
A flame extinguishing cylinder is installed in the flashback prevention chamber to extinguish backfire, and a check valve element and a shutoff valve element are installed back-to-back in the valve chamber at an appropriate distance from each other. A closing force is applied to the inlet hole, a closing force is applied to the shutoff valve body to the gas communication hole by a shutoff valve spring, and a sliding support hole is installed in the end wall on the opposite side of the valve chamber in the central space inside the flame extinguishing tube of the flashback prevention chamber. , insert the reset rod into the sliding support hole so that it can freely slide in the direction of distance from the valve chamber, insert a click stop device between the reset rod and the sliding support hole, and click the reset rod. The top device is configured to be able to switch between a reset position that approaches the valve chamber and a cutoff position that moves away from the valve chamber, and when the reset rod is advanced to the reset position, the inner end surface of the reset rod is moved by the position holding force of the click stop device. presses and holds the shutoff valve body in the valve open position against the shutoff valve spring, and the outer end surface of the reset rod retracts to a position where it does not protrude outside the sliding support hole, and the reset rod retreats to the shutoff position. In this state,
The present invention is characterized in that the inner end surface of the reset rod no longer pushes the shutoff valve element to the open position, and the outer end surface of the reset rod advances to a position protruding outside the sliding support hole.

Hereinafter, embodiments of the present invention will be described based on the drawings.

Figure 1 shows the dry flashback preventer during forward flow (normal state)
Figure 2 is a vertical cross-sectional view when a flashback occurs, and this dry type flashback preventer has a cylindrical flashback preventer main body 1 with one end open, and gas is led out to a peripheral wall 2 of the flashback preventer main body 1. A gas outlet pipe connecting portion 4 with a hole 3 formed therethrough is provided in a protruding manner, and a cylindrical flame extinguisher 5 made of a porous material such as sintered metal and a cylindrical shielding plate 6 are installed inside the flashback preventer main body 1. are arranged inside and outside, and a flame extinguisher holder 7 is fitted and fixed to the open end of the flashback preventer main body 1 to form a flashback prevention chamber 8 within the flashback preventer main body 1.

The flame extinguisher holder 7 is formed into a bottomed cylindrical shape with a flange whose central portion protrudes into the interior of the flame extinguisher. 5 is formed to sandwich the flame extinguisher holder 7, and a gas introduction pipe connecting portion 11 having a gas introduction hole 10 transparently formed in the opening 9 of the flame extinguisher holder 7 is fitted and fixed therein.
A valve chamber 12 is formed therein. A gas communication hole 13 is formed in the center of the inner end wall of the flame extinguisher holder 7 to communicate the valve chamber 12 and the flashback prevention chamber 8 . Inside the valve chamber 12, a check valve element 14 and a shutoff valve element 15 are housed back-to-back with an appropriate distance between them.

The leg portion 14a of the check valve body 14 is fitted into the valve chamber side passage portion of the gas introduction hole 10 so as to be able to slide forward and backward, and the check valve body 14 has a cavity formed inside the leg portion 14a. 14b and the valve chamber 12 are formed to communicate with each other through a through hole 14c opened in the peripheral side wall of the leg portion.

The leg portion 15a of the cutoff valve body 15 is fitted into the gas communication hole 13 so as to be slidable forward and backward.
The valve chamber 12 and the flashback prevention chamber 8 are connected to the cavity 15b formed inside the valve chamber 12 and the through hole 15c that opens in the leg circumferential side wall.
It is communicated with.

The cutoff valve body 15 is biased in the valve closing direction in which the through hole 15c enters into the gas communication hole 13 by a cutoff valve spring 16 interposed between the inner end surface of the gas introduction pipe connecting portion 11 and the check valve. The body 14 is biased in the valve closing direction by a check valve spring 17 interposed between the body 14 and the outer end surface of the cutoff valve body 15 so that the through hole 14c enters the gas introduction hole 10.

A reset rod holder 19 is fixed to the end wall 18 of the flashback preventer main body 1 in a penetrating manner, and a reset rod 20 is fitted into the reset rod holder 19 so as to be slidable forward and backward. A click stop device 23 consisting of a ball 21 and a spring 22 is attached to a portion near the outer end of the reset rod 20. By fitting the ball 21 of the top device 23, the reset rod 20 can be moved to a reset position where its outer end does not protrude from the outer end surface of the reset rod holder 19, and where its outer end does not protrude from the outer end surface of the reset rod holder 19. It is configured to maintain its posture with the protruding cutoff position.

When the reset rod 20 is in the reset position, the inner end surface of the reset rod 20 is in contact with the shutoff valve 15.
The valve chamber 12 and the flashback prevention chamber 8 are maintained in communication by pressing the leg portion 15a against the shutoff valve spring 16. Reference numeral 26 denotes a reset lever biasing spring that biases the reset lever 20 toward the cutoff position.

In the dry flashback device configured as described above, under normal conditions, the check valve 14 is pushed open by the gas pressure flowing in from the gas introduction hole 10, and the gas passes through the valve chamber 12, the flashback prevention chamber 8, and the flame extinguisher 5. The gas flows out from the gas outlet hole 3.

When a flashback occurs, the backflowing flame is extinguished by the flame extinguisher 5 when it flows in from the gas outlet hole 3, and the check valve body 14 is actuated by the explosion pressure flowing into the flashback prevention chamber 8. , immediately after reset rod 2
0 from the reset position to the cutoff position, and the cutoff valve body 15 is operated to cut off communication between the valve chamber 12 and the flashback prevention chamber 8.

Note that this flashback preventer operates not only when a flashback occurs, but also when abnormal pressure is generated within the flashback preventer, the pressure causes the shutoff valve body 15 to operate and cut off the gas supply.

As described in detail in the embodiments above, the dry flashback device of the present invention allows the gas to flow from the inside of the flame extinguisher to the outside during forward flow, and to one side of the inside of the flame extinguisher inside the flashback prevention chamber. Since a valve chamber is formed and a check valve element and a shutoff valve element are arranged back-to-back within the valve chamber, the flashback preventer can be made compact.

In addition, the shutoff valve body is biased to close the gas communication hole that communicates the valve chamber and the flashback prevention chamber, and the reset rod is inserted into the sliding support hole provided through the wall facing the gas communication hole of the flashback prevention chamber. is inserted so that it can slide in and out, and the reset lever is positioned at a reset position where the inner end surface of the reset lever opens the shutoff valve body against the shutoff valve spring, and at a shutoff position where the inner end surface of the reset lever is separated from the shutoff valve body. Since it is configured so that it can be held, in the event of a flashback or an abnormal pressure rise within the flashback preventer, the reset rod will protrude from the sliding support hole, making it easy to confirm the occurrence of an abnormality from the outside, and also prevent the reset rod from occurring. By pushing in the rod, the flashback preventer can be reset without disassembling it.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, with FIG. 1 being a vertical sectional view in a normal use state, and FIG. 2 being a vertical sectional view in the event of an abnormality. 1...Flashback preventer body, 3...Gas outlet hole, 5
...Flame extinguishing tube, 8...Flashback prevention chamber, 10...Gas introduction hole, 12...Valve chamber, 13...Gas communication hole, 14
... Check valve body, 15 ... Shutoff valve body, 16 ... Shutoff valve spring, 17 ... Check valve spring, 20 ... Reset rod, 23 ... Click stop device, 24 ... Sliding support hole .

Claims (1)

[Claims for Utility Model Registration] A flashback prevention chamber 8 is formed inside the main body 1 of the flashback prevention device, and a valve chamber 12 is formed on one side of the center of the flashback prevention chamber 8.
A gas introduction hole 10 is formed in the outer end wall of the valve chamber 12.
, a gas communication hole 13 is formed in the inner end wall thereof, a gas outlet hole 3 is formed in the peripheral wall of the flashback prevention chamber 8, and the gas introduction hole 10 is connected to the valve chamber 12, gas communication hole 13, and
A flame extinguishing cylinder 5 is provided in the flashback prevention chamber 8 to communicate with the gas outlet hole 3 through the flashback prevention chamber 8 to extinguish the flashback, and a check valve body 14 and a cutoff valve body 15 are disposed in the valve chamber 8. are placed back to back at an appropriate distance from each other, and the check valve body 1
4 to the gas introduction hole 10 with a check valve spring 17, and the shutoff valve body 15 to the gas communication hole 13 with a shutoff valve spring 16 to close and press the shutoff valve body 15 to the gas communication hole 13. A sliding support hole 2 is provided in the end wall opposite to the valve chamber 12 in the
4, the reset rod 20 is inserted into the sliding support hole 24 so as to be slidable in the direction of distance from the valve chamber 12, and the click stop device 23 is interposed between the reset rod 20 and the sliding support hole 24. The reset lever 20 is configured to be able to be switched between a reset position approaching the valve chamber 12 and a shutoff position moving away from the valve chamber 12 by means of a click stop device 23. Due to the position holding force of the top device 23, the inner end surface of the reset rod 20 presses and holds the shutoff valve body 15 in the valve open position against the shutoff valve spring 16, and the outer end surface of the reset rod 20 moves out of the sliding support hole 23. When the reset rod 20 is retracted to the shutoff position, the inner end surface of the reset rod 20 no longer pushes the shutoff valve body 15 to the open position, and the outer end surface of the reset rod 20 slides. A dry flashback preventer characterized in that it is configured to be in a state where it extends to a position protruding outside the support hole 24.