JPH0429220Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is a dry backfire method that uses flammable gas and oxygen to extinguish flashback flames caused by flashbacks in the supply lines of equipment that welds, melts, etc. metals. It concerns fire arresters.

[Conventional technology]

Conventional flashback preventers of this type extinguish the flashback flame using a flame extinguisher installed in the flame extinguishing chamber when a flashback occurs.
The flame extinguisher is made of sintered stainless steel powder, or it is made of a thin metal plate with many thin grooves etched on its surface that extend from the center toward the outer periphery and are open on the outer circumferential surface. was.

[Problem that the invention attempts to solve]

However, in the case of sintered metal, it is not only difficult to ensure a constant flow rate of gas due to the inconsistency and fluctuation of the passage interval area, but also the inconvenience of not being able to produce long cylindrical shapes, and the difficulty of passing a small volume of gas. Since the pressure drop is large, the anti-inflammatory effect is poor, and there are problems in that it is difficult to manufacture uniform products and the finished product is poor.

In addition, in the case of the latter thin metal plate, it is necessary to make the gas passage distance long, so the pressure resistance of the gas flow becomes large, the flame extinguishing effect is not improved, and the manufacturing process is time-consuming and maintenance and inspection is costly. There was a problem that required a lot of time.

This invention solves these problems,
To provide a dry type flashback preventer which allows a large amount of gas to pass through, has a small pressure drop, and is capable of effectively extinguishing flames generated when explosive combustion occurs in gas piping.

[Means for solving problems]

In order to achieve the above object, the dry flashback preventer of the present invention is a cylindrical body in which a large number of flame extinguishing plates 1 made of foamed metal with ventilation holes 2 in the center are laminated and crimped together. A flame extinguishing plate 3 is housed in a flame extinguishing chamber 7 between an inlet 5 and an outlet 6 of the preventer main body 4.

[Effect]

When gas flow is normal, flammable gas enters through the inlet 5, pushes open the check valve 8, enters the flame-extinguishing chamber 7, and flows between the inner peripheral surface of the preventer body 4 and the outer peripheral end surface of the cylindrical flame-extinguishing plate 3. The air flows out from the space formed in the space through the flat air bubbles 3a of each flame extinguishing plate 1, through the ventilation hole 2 in the center, and into the outlet 6.

In the case of backflow, the check valve 8 is closed by the backflow pressure to prevent the gas from flowing back toward the inlet 5 side.
When the pressure of the gas flowing back further increases, the internal pressure rises and exceeds a predetermined pressure, the safety valve 16 is pushed up toward and away from the valve seat 17a, and the internal gas is instantly released from the discharge port 19 to the outside.

If a backfire occurs next, the pressure inside the pipe will rise to several times the initial pressure due to an internal explosion in the pipe, and the flame will propagate back into the flame extinguishing chamber 7, but the backflow pressure will cause the check valve 8 to close. Move down and close. The flame is compressed from the central ventilation hole 2 of the cylindrical flame extinguishing plate 3 and passes through the bubble 3a which has been deformed into a flat shape, while effectively exhibiting an endothermic effect and instantly extinguishes the flame. Further, as in the case of backflow, the internal pressure rises, operating the safety valve 16 and releasing the internal gas from the discharge port 19. Rapid closing valve 15 due to acceleration at that time
When the spindle 15a is lifted, the quick-closing valve 15 comes into close contact with the lower valve seat 17b, and the flow of the supply gas from the gas inlet 5 to the gas outlet 6 is automatically closed.

〔Example〕

Hereinafter, referring to the drawings showing the embodiments of the present invention, reference numeral 1 is a foamed metal flame extinguishing plate made of nickel, nickel chromium, etc. with rounded square parts, and approximately 0.3 mm thick on the entire surface. It has air bubbles 1a, and there is a circular ventilation hole 2 in the center of the flame extinguishing plate 1.
has been drilled. Dozens of these flame-extinguishing plates 1 are laminated and compressed into one piece so that the thickness becomes 1/2 to 1/5,
It is formed into a cylindrical polymeric flame extinguishing plate 3 having a predetermined height. The bubbles 1a of each flame extinguishing plate 1 are compressed and changed into flat bubbles 3a. This cylindrical polymeric flame-extinguishing plate 3
is housed in a flame-extinguishing chamber 7 between an inlet 5 and an outlet 6 of the preventer main body 4. 8 is gas inlet 5
A check valve 9 for opening and closing is an annular pedestal on which a cylindrical polymeric flame extinguishing plate 3 is placed, and a recess 10 into which the shaft of the check valve 8 fits is provided in the center of the back surface, and a gas outlet 9a is provided on both side walls. It is received by a short cylindrical body 11 screwed onto the lower end of the preventer main body 4. 12 is a cylindrical body screwed onto the upper end of the preventer main body 4; 13 is a lid body screwed onto the top of the cylindrical body, and a vent hole 13a is bored in the center thereof. Numeral 14 is a valve seat to which the quick-closing valve 15 is joined, and 16 is a safety valve, in which a spindle 15a of the quick-closing valve 15 is inserted and fitted into a communication hole 16a in the center, so that they are integrated. Reference numeral 17 denotes an inwardly protruding wall surface provided on one side, and its inward tip portions are formed at the upper seat 17a and the lower seat 17b. 18 is a connecting pipe, and 19 is a gas discharge port.

An example of the use of the present invention configured in this way is that it is interposed in a supply path of a device or piping for supplying flammable gas, and during normal use, gas entering from the inlet 5 is passed through the check valve 8. is pushed up, enters the flame-extinguishing chamber 7, passes through the flat air bubbles 3a of each flame-extinguishing plate 1, and reaches the inlet 5 from the ventilation hole 2. Also,
When a flashback occurs due to an explosion inside the pipe, the check valve 8 is closed by the gas pressure, and the flashback flame absorbs heat while passing through the flat bubbles 3a of the cylindrical polymeric flame extinguishing plate 3, and is depressurized and extinguished. ing. At the same time, the safety valve 16 is activated to release gas from the discharge port 19, and the spindle 15a of the quick-closing valve 15 is lifted up and closed against the valve seat 17b, thereby stopping the gas supply.

〔effect〕

In the present invention, a cylindrical flame extinguishing plate 3 made by laminating and laminating a large number of flame extinguishing plates 1 made of foamed metal with ventilation holes 2 bored in the center is attached to the inlet 5 of the main body 4 of the preventer.
Since this relates to a flashback preventer housed in a flame-extinguishing chamber 7 between an outflow port 6 and a flame-extinguishing plate 1, the flame-extinguishing plate 1 is made of foamed metal, and the bubbles 1a are compressed into a flat shape 3a, and the polymerized flame-extinguishing plate 3 Since it is formed into a cylindrical body, the amount of gas passing through is large and the pressure resistance to flow is reduced. Therefore, in the case of flashback, the flame can be extinguished instantly by effectively absorbing heat.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a perspective view of a flame-extinguishing plate, FIG. 2 is a vertical sectional view thereof, FIG. The figure is a simplified partial enlarged view of the compressed flame extinguishing plate, FIG. 5 is a vertical cross-sectional view in a normal state, and FIG. 6 is a simplified vertical cross-sectional view in an abnormal state. DESCRIPTION OF SYMBOLS 1... Flame-extinguishing plate, 2... Ventilation hole, 3... Cylindrical flame-extinguishing plate, 4... Preventer body 4, 5... Inflow port, 6...
...outlet, 7...extinguishing chamber.

Claims (1)

[Scope of utility model registration request] A cylindrical flame extinguishing plate 3 made by laminating a large number of flame extinguishing plates 1 made of foamed metal with ventilation holes 2 in the center and crimping them together is inserted between the inlet 5 and the outlet 6 of the preventer main body 4. A dry flashback preventer housed in a flame extinguishing chamber 7.