JPH0132884B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an emergency automatic stop device for backflow and backfire of gas in gas equipment piping, and more specifically, the present invention relates to an emergency automatic stop device for backflow and backfire of gas in gas equipment piping, and more specifically, the present invention relates to an emergency automatic stop device for backflow and backfire of gas in gas equipment piping. The present invention relates to a stop device incorporating a filter unit that removes carbon, attenuates the shock waves of propagating backfires, and diffuses and extinguishes the backfires.

There have been various types of safety devices in the event of abnormal combustion in gas equipment that uses gases such as acetylene, hydrogen, methane, etc. for welding, fusing, thermal spraying, heating, etc. However, one such device, as disclosed in Japanese Patent Application No. 52-62300, is a device that functions for both gas backflow and backfire. The present invention relates to improvements to said device.

Conventionally, this device functions effectively against both gas backflow and flashback, but if abnormal combustion occurs repeatedly in the gas piping, carbon particles will adhere to the inside of the device, which is particularly harmful to the device. If even a small amount of carbon adheres to the inlet valve, which is an important component,
The disadvantage is that the valve becomes difficult to operate smoothly, making it difficult to sufficiently prevent gas backflow, which is the function of an inlet valve.

In order to solve the above-mentioned drawbacks, the present invention incorporates a filter into the device to remove carbon mixed into the device, and also adjusts the elastic force of each elastic body so that each valve can operate smoothly. use,
The system is designed to ensure that the inlet and outlet valves operate smoothly at all times, and the details are explained based on an example shown in a drawing. Figure 1 shows the entire equipment for gas welding, etc., equipped with this stop device. The explanatory drawing and Fig. 2 are diagrams of the gas collection piping system.As shown in the drawing, the stop device 3 is installed near the outlet of the gas cylinders 1, 1a, 1b or in the middle of the piping, and if combustion abnormality occurs in the blowpipe 2, etc., gas backflow occurs. - When flashback occurs, the stop device 3 automatically shuts off the gas line.

FIG. 3 is an explanatory internal cross-sectional view of this stopping device,
The main body case is the inlet side case 4 and the outlet side case 4a.
divided into two parts, screwed together to form a single body,
A gas flow path is provided through the interior, and the ends of the flow path are used as an inflow hole and an outflow hole, and threaded portions 5, 5a for connection with gas equipment piping are provided on the outer periphery of each end. The inlet valve 6, the outlet valve 6a, and the filter unit 7 are assembled, and the outlet side case 4a has a screw hole 8 for attaching a valve locking body, which will be described later.
A stopper hole 10 and a gas escape hole 11 are provided at the bottom 9 of the screw hole 8.

The inlet valve 6 opens the gas inlet hole 16 when gas pressure from the cylinders 1, 1a, etc. is applied to the inlet side A, causing gas backflow, etc.
In other words, when gas pressure is applied from outlet side B,
The gas inflow hole 16 is closed, and in the embodiment shown, a substantially cylindrical body with one end closed is inserted halfway into the inlet hole 12, and the gas inflow hole 16 is closed at the outer periphery. An annular closing member 13 such as a rubber O-ring is provided in one or two stages to provide sealing performance of the valve, and an annular closing member 13 is provided behind the inlet valve 6 to the extent that the inlet valve 6 can be opened by gas inflow pressure. An elastic body 14 made of a spring or the like having an elastic force
are placed in contact with each other. Note that the closing member 13 is provided to improve the sealing performance of the inlet valve 6 and to prevent gas leakage, and the closing member 13 does not necessarily have to be used. Further, when two O-rings are used side by side as shown in the figure, the sealing performance of the inlet valve 6 can be further improved compared to when one O-ring is used.

Normally, the outlet valve 6a is temporarily locked by a valve locking body 19 to keep the outlet hole 12a open, and gas freely passes through the outlet hole 12a, but gas may be under high pressure such as when flashback occurs. The temporarily locked state is released when the gas pressure of The outlet hole 12a is closed by the action of a bullet body 15, which is a spring or the like which is separate from the bullet body 14. In the example shown, the tip is formed into a tapered shape that can be closely contacted with the outlet hole 12a, and if necessary, a closing member 13a similar to the inlet valve 6 is attached to the tip, and the tip is closed. Gas outflow hole 1 at the rear of the
For example, a plurality of holes 6a are bored in a circumferential shape, and a cylindrical body 17 continuous with the tip part has an elastic body 15 such as a spring built therein, and a continuous or intermittent annular ring is formed on the outer periphery. A recessed portion 18 is provided around the periphery.

The valve locking body 19 has a function of temporarily locking the outlet valve 6a, and in the embodiment, the valve locking body case 22 is equipped with a stopper 21 that is pressed by an elastic body 20 such as a spring. Outlet side case 4a
Insert the inside of the case 22 into the screw hole 8 at the bottom of the screw hole 9.
The shaft 21a of the stopper 21 is inserted through the stopper hole 10, and the shaft 21a is fitted into the recess 18 of the outlet valve 6a. Furthermore, in the illustrated example, an opening 23 for blowing gas is formed in the upper part of the valve locking body case 22 in order to make the operation of the stopper 21 smoother, and a packing material 24 is formed on the opening 23.
An opening 28 in which a pusher 25 having a shape is placed and pressed by an elastic body 26 such as a spring.
A cap 27 is attached.

The filter unit 7 protects the inside of the device described above, in particular, prevents carbon from adhering to the inlet valve 6, maintains its smooth operation, and diffuses and extinguishes back flame. The unit 7 has a substantially cylindrical filter case 29 screwed into the outlet side case 4a, and a gas flow path is formed between the inside of the outlet valve 6a and the inside of the filter case 29. Cylindrical filters 30 having continuous through holes are fixed at intervals so as to cover the gas passage holes 32 bored in the main body of the filter case 29, which is a cylindrical body, and the wall of the filter 30 is arranged to cover the gas passage holes 32 formed in the main body of the filter case 29. It is arranged so that it crosses the road. Further, in the present invention, a cylindrical flow obstruction pipe 33 is loosely fitted between the case 29 and the filter 30 so as to be freely movable in the longitudinal direction. For this reason, gas flows through the passage hole 3 during backflow and flashback.
2 does not flow directly toward the filter 30 locally, but instead spreads to the left and right by the flow obstruction pipe 33 and flows into the entire filter 30, the gas flow path becomes a labyrinth, and the flow between this and the through hole of the filter 30. to prevent backflow and attenuate the shock wave during backfire,
Can spread and extinguish backfire flames. Due to the characteristics of this device, the filter 30 used is made of a heat-resistant and impact-resistant sintered alloy that can withstand backfire and shock waves generated, and is made of metal such as stainless steel, nickel, chrome, titanium, etc. Examples include sintered products. It is also effective to arrange a filter 31 inside the filter case 29 if necessary, and if a fibrous stainless steel material is used, it can particularly attenuate the shock wave of the backfire that has propagated, and also diffuse the backfire.・Effective in extinguishing inflammation.

The configuration of the stop device 3 is as described above. During normal operation, gas from the cylinders 1, 1a, etc. as gas supply sources is fed into the device 3 by pushing the inlet valve 6 with its gas pressure to open the gas inlet hole 16. , passes through the filter 30 and enters the gas passage hole 32 and the gas outlet hole 1.
6a and flows out through the open outlet hole 12a. On the other hand, if reverse flow occurs due to abnormal combustion, etc., that is, the gas pressure is lower than the inlet side A and the outlet side B
When the gas becomes high, the gas flows backward in the opposite direction to the aforementioned flow and flows from the outlet valve 6a toward the inlet valve 6. As a result of the pressure of the gas itself acting on the back of the inlet valve 6, the gas automatically The inflow hole 16 is closed. Further, even if some of the residual carbon in the gas piping gets mixed into the device 3 when the gas flows back into the device 3, it will not affect the inlet valve 6 because it will be removed by the filters 30 and 31.

In addition, when gas flashback occurs, there is generally a difference in the propagation speed of the shock wave caused by the flashback and the flashback flame, and the shock wave first reaches the open outlet hole 12a from the exit side B, and then exits. At the same time as it enters the outflow hole 16a of the valve 6a, it passes through the gas escape hole 11,
The shock wave acts on the lower surface of the stopper 21 in the valve locking body 19, pushing up the stopper 21 and closing the outlet valve 6.
As a result of releasing the locked state of a, the outlet valve 6a strongly closes the outlet hole 12a by the force of the elastic body 15, sealing high pressure backflow gas between the inlet valve 6 and the outlet valve 6a,
With each valve pressed outward from the inside, each hole is closed to block any subsequent flashback.

Also, before the stopper 21 operates, the gas outlet hole 16
Even if there is a flame that enters the device 3 through the filters 30 and 31, the flame is diffused and extinguished and the trace amount of carbon contained in the flame is removed. Therefore, the inlet valve 6 is always closed. Protected from carbon adhesion by filters 30 and 31,
Valve function does not deteriorate.

The stopper 21 activated by backfire can be reused by pushing the outlet valve 6a into the device 3 from the outlet side B with a shaft or the like, and engages with the recess 18 of the outlet valve 6a again. is case 4, 4a
It can be disassembled and cleaned periodically, and by replacing the filters 30 and 31, it can be used for a long period of time.

In addition, since the elastic bodies 14 and 15 are provided separately, and those with elastic force that can be adapted to the target gas pressure are selected and used, the operation of each inlet and outlet valve is quick and quick. It is reliable and allows gas to flow in or stop.

As described above, since the present invention has a cylindrical filter made of sintered metal mounted inside the main body case using a filter case, the filter is easy to install, and even if clogging occurs, it is easy to replace and clean the filter. Furthermore, by adopting this structure, flashback can be dispersed and passed through the entire wall of the filter in the thickness direction, resulting in a high flame extinguishing effect and a high shock wave damping effect.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and Fig. 1 is an overall explanatory diagram of equipment such as gas welding equipped with this stop device, Fig. 2 is a diagram of a gas collecting piping system, and Fig. 3 is a diagram of this stop device. It is an internal cross-sectional explanatory view of. 1, 1a, 1b; gas cylinder; 3; stop device;
6; inlet valve, 6a; outlet valve, 7; filter unit, 11; gas escape hole, 12; inlet hole, 12a;
Outlet hole, 13; Closing member, 14; Inlet valve bullet projector,
15; Exit valve projectile, 21; Stopper, 29;
Filter case, 30; Filter, 31; Fiber filter, 32; Gas passage hole, 33; Flow obstruction tube.

Claims (1)

[Claims] 1 A gas flow path is formed through the inside of the main body case, and the ends of the flow path are used as inflow holes and outflow holes. A cylindrical filter case made of sintered alloy is attached to the main body case, and has continuous through holes at intervals on the outside of the filter case main body, and has heat resistance and impact resistance that can withstand backfire and shock waves. The filter is fixed, the wall of the filter is arranged to cross the gas flow path, and a cylindrical flow obstruction tube is loosely fitted between the filter case body and the filter so as to be freely movable in the longitudinal direction. Gas backflow/backfire emergency automatic stop device.