JPH018838Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a water seal type safety device in a flammable gas piping system.

Conventionally, when using flammable gases alone or mixed gases of combustible gases and combustion-supporting gases, etc., backfires and backfires accompanied by combustion that occur for some reason in gas pipes or in large-flow piping systems have been reported. In order to prevent back flames from propagating to the gas supply source and igniting them in the event of a gas explosion, it is regulated by law to install and use a water-sealing safety device in piping systems with large flow rates. .

However, the gas flow rate in the piping system is
Due to the large flow rate of m ³ /hr, bubbles form when passing through the water seal, resulting in a violent boiling state, and as a result, multiple bubbles coalesce inside the water seal to form a gas passage, and such gas If flashback occurs under the feeding conditions, the flashback flame may propagate to the gas supply source side through the gas passageway, and the water sealing function may not be achieved.Especially in the case of mixed gas, the combustion temperature is high and the explosion pressure is high. Because the gas is so large, there remains a risk that the back flame could ignite the gas supply source and cause a major explosion.

The present invention was made to solve the problems with conventional water-sealed safety devices.
This prevents the backflow of a single flammable gas or backfire from propagating to the gas supply source and igniting it, and also prevents the combustion temperature and explosion pressure from being high, such as in the case of a mixed gas of combustible gas and combustible gas. The purpose is to ensure that backfire can be extinguished even in the event of a major flare-up.

Hereinafter, details of the water seal type safety device for a flammable gas piping system of the present invention will be further explained based on the attached drawings.

The water seal type safety device installed in the piping system of the gas supply line connects a gas introduction pipe 2 to the lower part of a bottomed cylindrical body 1 with an upward opening, and a gas delivery pipe 3 to the upper part thereof. As shown in the figure, the lower part of the main body 1 and the gas inlet pipe 2 are filled with a liquid for preventing the propagation of flashback such as water or antifreeze to form a water seal part 4. Ru.

Further, a vertical standing part is provided at a suitable place of the gas introduction pipe 2, for example, by standing the main body 1 side vertically from the check valve 5,
A cylindrical body 6 whose inner diameter is larger than the inner diameter of the gas introduction pipe 2 and whose volume per unit length is larger than that of the gas introduction part 2, specifically, several times larger than the gas introduction part 2, is installed in the vertical upright part. Installed in an upright manner in an airtight manner,
A cylindrical flame extinguishing filter 8 is housed in the hollow portion 7 of the cylinder 6 with a space between its outer peripheral surface and the inner surface of the cylinder 6.

In the illustrated embodiment, the cylinder 6 has an upper end opening threadedly connected to a support member 9 that is continuous with the check valve 5, and a lower end wall 6' of the cylinder 6 having a diameter smaller than the inner diameter of the gas introduction pipe 2. A flow path 10 is formed, and the flow path 10
The gas introduction pipe 2 is screwed and connected to the gas introduction pipe 2 so that it is interposed in the middle of the gas introduction pipe 2, and a cylindrical anti-flame filter 8 is installed in the hollow part 7 of the cylindrical body 6. A supporting member 9 serving as a closing portion for the upper end of the flame-extinguishing filter 8 is fitted onto the ventilating tube 11, which has a number of vent holes 11' vertically provided below the center thereof, at intervals at intervals in the side wall thereof. A bolt 12 is screwed onto the lower end and clamped and fixed between the bolt head 12' and the support member 9, thereby closing the lower end of the flame-extinguishing filter 8 and simultaneously connecting the inside of the ventilation cylinder 11 and the gas supply source side of the gas introduction pipe 2. are connected in series.

Further, a space is provided between the lower end of the flame-extinguishing filter 8 and the inner lower end surface of the cylindrical body 6.

Then, the feed gas that has passed through the gas introduction pipe 2, the check valve 5, the support member 9, the vent pipe 11, and the vent hole 11' is transferred from the inside of the flame-extinguishing filter 8 to the outside cylindrical body 6 as shown by the arrow in the figure. The gas flows out into the hollow part 7 of the hollow part 7, and is fed from the hollow part 7 to the water seal part 4 via the flow path 10 and the gas introduction pipe 2 again.

In addition, 14 in the figure is a rupture plate that blocks the upper opening of the main body 1 made of a thin metal plate, etc., and a part of the lever 15 provided in conjunction with the check valve 5 is positioned above the rupture plate 14. The rupture plate 14 is destroyed by flashback pressure and shock waves generated when flashback occurs, and the check valve 5 is operated via the lever 15 to close the gas introduction pipe 2.

According to such a structure, even if the flashback flame propagates toward the gas introduction pipe 2 side through the gas passage created by the coalescence of the feed gas bubbles in the water seal section 4 when flashback occurs, the cylinder body 6 Since the inner diameter is larger than the inner diameter of the gas introduction pipe 2 and the volume is large, the speed of progress of the flashback is slowed and attenuated, and the flame extinguishing filter 8 in the cylinder body 6 directs the flashback flame to the gas supply source side. This makes it possible to reliably prevent the fire from spreading to other parts of the body and igniting it.

In addition, when flashback occurs, flashback pressure acts from above the water seal part 4 in the main body 1, so that
As the water level in the water seal section 4 in the water introduction pipe 2 rises, floating rust, dirt, etc. mixed with the liquid in the water seal section 4 enters the hollow section 7 of the cylinder body 6, causing fine particles to be removed from the flame-extinguishing filter 8. Although there are problems such as clogging of the holes, in the present invention, the inner diameter of the cylinder 6 is made larger than the inner diameter of the gas introduction pipe 2, and the flame-extinguishing filter 8 is placed in the upper part of the hollow part 7 of the cylinder. Since the water level in the water seal section 4 that has risen inside the gas introduction pipe 2 is
The inner diameter and volume of the cylindrical body 6 and the distance from the lower end of the quenching filter 8 to the cylindrical body 6 must be controlled in order to suppress the rising of the quenching filter 8 and to prevent the quenching filter 8 from submerging in water.
If the length to the internal lower end face is made as large as possible,
It becomes more effective.

Moreover, not only the inner diameter of the cylindrical body 6 can be made large, but also the inner diameter of the gas introduction pipe 2 from the cylindrical body 6 to the main body 1 can be made the same diameter as the inner diameter of the cylindrical body 6.

Here, when a flashback occurs, the flashback pressure and shock wave act on the flame-extinguishing filter 8 from the outer circumferential surface toward the inside in the opposite direction of the arrow shown in the figure, thereby reducing the shape strength of the cylindrical flame-extinguishing filter 8. It can be used effectively to eliminate the risk of damage, etc., and if rust, dirt, etc. in the water seal section 4 is
Even if they adhere to the cylinder body, the feed gas pressure during normal flow will cause them to fall off, and the clogging will be removed from the hollow part 7 of the cylinder body 6.
It is possible to solve the problem of the flame-extinguishing filter 8 being deposited inside the flame-extinguishing filter 8 and having to remove the flame-extinguishing filter 8 itself to remove it.

Furthermore, a cylindrical body 6 containing this flame-retardant filter 8 is provided.
As shown by the dashed line in the drawing, it is also possible to install the check valve 5 in the gas introduction pipe 2 at an appropriate location on the gas supply source side or in the gas delivery pipe 3, and the function of the flame-extinguishing filter 8 is to prevent backfire from occurring. In addition to reliably extinguishing flames and attenuating backfire pressure and shock waves, it is also necessary not to impede gas flow during normal gas supply, so we developed a structure with countless micropores uniformly. The material used is sintered metal, ceramics, synthetic resin, etc.

In the water seal type safety device for the flammable gas piping system of the present invention as described above, when a flashback occurs, the gas is introduced through the gas passageway due to the coalescence of the feed gas bubbles in the water seal section 4. Even when the flame enters the pipe 2 side, the flame extinguishing filter 8 inside the cylinder body 6 can reliably extinguish the flame and prevent the flame from igniting to the gas supply source side. Since the volume is made larger than the inner diameter, even if the water level in the water seal part 4 in the gas introduction pipe 2 rises due to flashback pressure when flashback occurs, it will not flow into the hollow part 7 of the cylinder body 6. Once that happens, the rate of water level rise will slow down.

In addition, since the flame-extinguishing filter 8 is provided within the cylindrical body 6 at a distance from the water seal portion 4,
There is no fear that the flame-extinguishing filter 8 will be submerged in water and that rust, dirt, etc. floating in the water seal section 4 will adhere to the micropores and cause clogging.

In addition, although it is a miniaturized device with a three-layer structure that includes a flame-extinguishing filter 8 in which a ventilation pipe 11 having a ventilation hole 11' is located inside the cylinder body 6,
Backfire that has entered beyond the water seal section 4 is attenuated once when it passes from the gas introduction pipe 2 through the cylindrical body 6 whose inner diameter is set large, and then passes through the fine holes of the flame extinguishing filter 8 and the vent pipe 11. It is damped again when reaching the gap between
Since it is attenuated when it reaches the inside of the vent pipe 11, the flashback that has entered the gas introduction pipe 2 beyond the water seal part 4 is surely attenuated, and the flashback is surely prevented from entering the gas supply source side. It can be prevented.

[Brief explanation of the drawing]

The drawing is a front view, partially in section, showing an embodiment of the water seal type safety device for a flammable gas piping system according to the present invention. 1: Main body, 2: Gas introduction pipe, 3: Gas delivery pipe,
4: Water seal part, 5: Check valve, 6: Cylindrical body, 7: Hollow part, 8: Antiflame filter, 9: Support member, 10:
Flow path, 11: Ventilation cylinder, 12: Bolt, 14: Destruction plate, 15: Lever.

Claims (1)

[Scope of utility model registration request] The upper opening of the main body 1 in the form of a bottomed cylinder with an upward opening is shielded by a destruction plate 14, and the gas delivery pipe 3 is connected to the upper part of the main body 1, and the gas introduction pipe 2 is connected to the lower part of the main body 1. The inlet pipe 2 is erected at a proper position in a vertical position, and a cylinder 6 having an inner diameter larger than the inner diameter of the gas inlet pipe 2 is interposed in the vertically standing part in an airtight manner. Inside the hollow part 7 is a ventilation cylinder 11 whose lower end is closed and a number of ventilation holes 11' are bored in the side wall with spaces between them and the inner surface. A cylindrical flame-extinguishing filter 8 having a uniform number of fine pores closed by the formed closing part is arranged such that its lower end is spaced apart from the inner lower end surface of the cylinder body 6 and its outer peripheral surface is spaced from the inside surface of the cylinder body 6. It is installed internally with an opening, and communicates and connects the inside of the ventilation cylinder 11 with the gas supply source side of the gas introduction pipe 2, and also allows liquid such as water to flow between the lower part of the main body 1 and the lower part of the gas introduction pipe 2 below the cylindrical body 6. A water seal type safety device for a combustible gas piping system, characterized in that a water seal part 4 is formed by sealing.