JPS5941708A - Back-flow and back-fire prevention device for gas - Google Patents

Abstract

PURPOSE:To provide a positive closing in case of back-flow and back-fire by a method wherein a main body of a device comprising an inlet casing and an outlet casing combined to each other is provided with an opening only except the flow inlet and the flow outlet to form a closed system. CONSTITUTION:Under a normal flowing condition of gas, the gas flowed in at the flow inlet P presses a check valve 8 inwardly against a resilient force of a spring 14, flows to an inlet port from a passage hole 8' of the check valve 8, passes through a passage 3' of a filter case 3, passes through a flame diminishing filter 7, passes near the circumferential walls of the inlet casing 1 and the outlet casing and then flows out from the outlet port Q as shown by an arrow. In case of forming a back-fire, a flowing-in of a shock-wave preceeding to the back-fire into the main body of the device causes at first the shock-wave to act against a flange part 12b of a pressure accepting ring 12, the pressure accepting ring 12 is slid along a main body 11 of guide against a spring 16, and each of the balls 13 pressed inwardly against a small diameter part 12' of a cylindrical part 12a of the pressure accepting ring 12 is made free, a closing valve 9 biased by a spring pushes each of the balls 13 toward an outside of the open hole 11', slides toward the outlet port Q to close the outlet port.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a backflow and flashback cutoff device that is essential for gas, that is, it prevents the mere backflow of raw gas and also prevents the backflow flame from propagating through the sponge 1 when a flashback occurs. Regarding the device ff, which reliably prevents accidents such as accidents, the main feature is that the main body of the device, which consists of a combination of an inlet side case and an outlet side case, does not have any openings other than the inlet and outlet 11. It is a closed type without a backflow and backfire.
It is a matter of heat theory to ensure that the backflow raw gas and flashback fire are discharged outside the equipment, causing a secondary disaster υ).
The idea is to prevent convexity and steepness.

In this type of conventional backflow and flashback shielding device I'c, especially when the operation of a 1tlinor is performed,
ii At the same time as letting the sludge +- and -2 escape from the device, create a part that operates the λ rib r, and then close the sludge at Arai and reduce the impact pressure. There is also an iCL that discharges the backfire flame to the device ft/A, but these are not preferable due to the fear of secondary disasters as mentioned above.The present invention solves three problems. The device A was developed in the laboratory, and will be explained below based on the embodiment shown in the attached drawings.The proposed device A consists of a case 1 on the artificial side and a case 2 on the outlet side connected to each other by screws at the bottom of the tank. Inside is an anti-flame filter made of materials such as sintered metal.
A filter case 3 having four parts 4゜5 and a flange 6 is provided, a through hole 8' is provided in the cylinder at the inlet portion of the main body, and a non-return screw W:f is equipped with an O-ring 10.
8 is slidably fitted into the base, and is held elastically by a spring 14 provided between the flange of the check valve 8 and the four parts 4 of the filter case 76. - A cutoff valve 9 for blocking the outflow port and a guide body 11 for slidably fitting and holding the cutoff valve 9 are provided at the outflow port in the power wood body, and the guide body 11 is slidably fitted to the outside of the id body 11 and reversed. A pressure receiving ring 12 is provided which is actuated by impact pressure when a fire occurs to enable the shutoff valve 9 to move in the direction of closing the outlet. The guide body 11 is screwed and fixed into the recess 5 of the filter case 3, and an O-ring 1o is installed between the collar parts 9' and 9' in the cylinder body, and an annular recess ##9a is formed on the circumferential surface. The cutoff valve 9 is slidably fitted therein, and is always urged by a spring 15 in the direction of closing the outlet.

Then, a bow/I/16 having a diameter larger than the depth of the hole, that is, the thickness of the peripheral wall of the guide body 11, is fitted into the hole 11' of the guide body 11, and the pole An annular enclosure of the shutoff valve 9 is created by projecting into and out of the aperture 11'. #9a
The movement of this pawl is restricted by a ball contact portion formed inside the cylindrical portion 12a of the pressure receiving ring 12 described above. That is, the pressure receiving link 12 consists of a flange portion 12b and a cylindrical portion 12a, which are protruded perpendicularly to the direction of movement in order to receive counter pressure. At the same time, the spring 16 interposed between the filter case 6 and the filter case 6 is constantly biased in the direction of the outlet (-C), and the ball abutment part provided on the inner surface of the cylindrical part 12a. The small diameter portion 12' is the aperture 11 described above.
When touching each bow/l' 1.15 within ', the pole projects inwardly from the aperture 11' and enters the groove 93 of the shutoff valve 9.
The sliding of the pressure receiving ring 12 causes the small diameter E;
When the press-contact state of fL is released, each ball 16 opens the hole 11'.
It becomes possible to move and protrude outward, and the shutoff valve 9 is pulled by the spring 15. Since the pressure is f, this spring is 150
As the +Qli;fr valve ψ slides in the direction of closing the outlet due to its elasticity, each ball 16 is released from the engagement with the annular recess j+cutter 9a and is pressed against the circumferential surface of the shutoff valve 9. The large diameter portion 12 of the pressure receiving ring 120 protrudes outward from the opening 11'.
'It comes into contact with the inner surface and is prevented from protruding further.

That is, in the pressure receiving ring 12, during normal flow of the body, the small diameter portion 12' of the pole contact portion formed on the inner surface of the cylindrical portion 12a contacts each port Iv13 and engages and locks the ball and the interrupter f9. In this way, the spoon r9, which is biased toward the outlet by the spring, is held in the outlet open state.In addition, in an emergency, the pressure receiving ring 12 is released by the spring due to the impact wave when a backfire occurs. 16, the bow/I/16, which was being pressed by the small diameter portion 12', will move against the cylindrical portion 1 of the pressure receiving ring 12.
The ball 16 reaches the upper part 12' of the human body 2a, and thus each ball 16 can freely move outside the opening 11'. When each ball 16 is able to move outward, the shutoff valve 9, which is normally biased by the spring in the four parts 5, pushes the ball 16 outward and connects the ball with a ItJr.
The fitting of the valve 9 with the concave groove 9a 1-system locking easily removes h.
Due to the elasticity of the spring, the shutoff valve 9 immediately closes the outlet.

Therefore, in the present invention, the cylindrical portion 12a of the pressure receiving ring 12
The small diameter part 12' and the large diameter part 12'' of the ball abutting part formed on the inner surface are formed by forming the small diameter part 12' in a linear shape closely to the circumferential surface of the guide body 11, as shown in FIG. Either form a large diameter part 12' with continuous light spread as a 9-shaped slope 1 (19), or form a straight line HlX in both the small diameter part 12' and the large diameter part 12' as shown in FIG. A stepped portion 12'' may be recessed between the small diameter portion 12' and the large diameter portion 12'; It is preferable to make the large diameter portion 12'' sloped in the upward direction shown in Fig. 1, and in the case of the 14th case having a stepped portion 12'' as shown in Fig.
12' and the continuous portion with the small diameter f11-12' are rounded.

Therefore, as an example of f+lx of the present invention, as mentioned above, the check valve 8 and the shutoff valve 9 are not provided in the same tree X+A, but are each individually sealed. The anti-inflammatory filter 7 can be installed in the main body A, or the anti-inflammatory filter 7 can be installed separately from the check valve 8 and the shut-off valve 8.
``It is also iJ ability to do something like ``J!''
The ball 16 for performing the operation wind i+il of the j valve 9 is fitted and installed in the opening 11' (at this time, the ball 16 is inserted into the hole 11').
In order to prevent E from passing through the apertures 11' and falling into the guide body 11, each aperture 11' leaves a protruding edge 11'' on the inside as shown in Figure 4A. In addition, the pressure receiving ring 12
The flange portion 12b operates the pressure receiving ring 12 in response to the back pressure of the pond when a flashback occurs, so the outer diameter of the flange portion is set to be large or small in consideration of the degree of back pressure applied to the flange 12b. The ball 13 mentioned above is usually a steel ball, which is melted at a predetermined temperature. If the device is made of heat-soluble synthetic resin or the like, if the device of the present invention is heated to a certain temperature or higher for some reason, the Hataorai 9 will become the spring 1 due to the melting of the po/v16.
Outlet with elasticity of 5. Since the backflow and flashback are shut off, it is possible to cut off the supply of raw gas and prevent the risk of explosion due to high temperatures.

Next, the present invention: I! To explain one operation, under the normal flow condition of the gas body, the gas flowing through the inlet port P presses the check valve 8 inward against the elasticity of the spring 14, thereby closing the through hole of the check nozzle r8. 8' into the inflow port, passes through the vent 6' of the filter case 3, passes through the anti-inflammatory filter 7, passes through the artificial side case 71 and the vicinity of the outlet side case peripheral wall, and connects to the case peripheral wall and the pressure receiving ring as shown by the arrow in the figure. The gas flows out from the outlet Q through the gap between the outer edge of the flange portion 12b and the gap between the flange portion 12b of the flame retardant filter 7 and the filter case 6. It passes through the vent 6' into the fourth part 4, and the spring 14i provided in the recess 4
Since JP8 is closed, this backflow is prevented from flowing further back toward the inflow port P. On the other hand, when a flashback occurs, a shock wave that precedes the flashback flame flows into the main body of the device, and a shock wave first acts on the flange portion 12b of the pressure receiving ring 12, so that the pressure receiving ring 12 moves along the guide main body 11 and Rub against spring 16! cylindrical portion 1 of the pressure receiving ring 12
Each bow/I/16 which had been suppressed inward by the small percentage portion 12' of 2a is freed, and the shutoff valve 9 biased by the spring as described above releases each bow/l'13. hole 11
When pushed out toward the outside of the outlet 1', the murine 9 itself is pushed out in the direction of the outlet Q, thereby closing the outlet 1'. On the other hand, in order to restore the device body A to its original state after shutting off the backfire, remove the pipe connected to the outlet side case 2, insert the rod 18 from the outlet Q, and press the shutoff valve 9 against the spring 15. Then, the position where the shaped recess n9a and each ball 13 can be fitted again is reached, and at this time the pressure receiving ring 12 is pressed against the spring 16.
The small diameter portion 12' of the cylindrical portion 12a returns to the original position by pushing the ports, /I/16, etc. one inward key to close the shutoff valve 9 again as shown in FIG. This is to keep the outlet Q open. In the figure, reference numeral 17 indicates an O-ring attached to the connecting portion of the inlet side case 1 and the outlet side case 2.

According to the backflow and flashback blocking device of the present invention as described above, the backflow prevention and flashback blocking mechanism is configured such that the inlet side case 1 and the outlet side case 2 are opened once except for the gas inlet and the gas outlet.
It is installed inside the device main body A which is connected in a sealed manner with no gaps, to block backflow and flashback within the main body A, and to prevent backflow raw gas, shock waves and flashback flames from being discharged outside the device main body A. As a result, there is no risk of degrading the working environment due to raw gas discharged outside the device, backfire shock waves, or flames or causing secondary flame damage such as explosion, and the main body A is a sealed type. When flashback occurs, the pressure inside the core body increases due to the back pressure that has entered the main body until the shutoff valve 9 closes the outlet Q, and this internal pressure causes the shutoff valve 9 to close.
, the check valve 8 is pressed against the outflow port and the inflow port to close them, and together with the elasticity of the springs 14 and 15, this ensures the closure of the outflow port and the inflow port. By accommodating and installing all the parts in the mold body A, safety devices etc. are attached to the outside of the body as in the past (compared to the 114-piece construction, this not only has advantages in terms of assembly work and cost, but also reduces the cost of the entire device). It becomes possible to reduce the size and weight.

On the other hand, since the pressure receiving ring 12 receives reverse pressure on the entire surface of the flange portion 12b formed upright perpendicular to its operating direction, the response is quick and the sliding due to the receiving pressure is quick, thereby closing the outlet Q by the shutoff valve 9. This can be done immediately, and since the guide body 11 is screwed and fixed to the filter case 6, by adjusting the degree of screwing (depth), the shutoff valve 9 is biased in the direction of closing the outlet. By adjusting the elastic force of the spring 15 or by appropriately selecting and using the elasticity of the spring 15 itself, it is possible to adjust the closing force of the outlet Q by the cutoff valve 9. protrudes in the axial direction to close the outlet Q, so even if there is a slight error in the length direction in the formation position of the closing part Q' of the outlet, it is possible to absorb this and maintain a completely closed state. be.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view showing an embodiment of the present invention when gas is flowing normally, Fig. 2 is a longitudinal cross-sectional view when flashback occurs, and Fig. 3 is another example of the ball contact portion on the inner surface of the pressure receiving ring. A 15-minute vertical cross-sectional view showing the opening in the guide body.
It is an i-side view. A: Device main body, P: Inlet, Q: Outlet. 1: Inlet side case, 2: Outlet side case, 6: Filter case, 4.5: Recess, 6: Flange, 7: Anti-flame filter, 8: Check valve, ? = Shutoff valve, 10:0 ring, 11
Ni guide body, 12: Pressure receiving ring, 16: Pole, 14
．． 15.16: Spring, 17: 0 ring, 18: Rod. Figure 4-47-1

Claims (1)

[Scope of Claims] l) A guide body 11 having a plurality of openings 11' formed in a cylindrical part in a closed device main body in which only the gas inlet and outlet are open is used as the outlet. A cutoff valve 9 having an annular groove 9a formed on the circumferential surface and an O-ring 10 attached to one end is slidably fitted inside the cylinder of the guide body 11 with a spring. Always biased in the direction of closing the outlet,
In order to keep this shutoff valve 9 in the outlet open state, a ball/L/16 having a diameter larger than the depth of the hole is fitted into each hole 11' of the guide body 11, and each ball 16 is connected to the ball 16. The annular enclosure 4t9a of the shutoff valve 9 can be fitted and locked, and the guide body 11 has a flange portion 12 on the outer periphery that receives impact pressure during flashback.
A pressure receiving ring 12 consisting of a cylindrical portion 12a and a cylindrical portion 12a is slidably fitted on the outside and always urged toward the outlet by a spring, and each of the above-mentioned poles l'L/13...・
The guide main body 11 of each bow/L'13 and the small diameter portion 12' to be pressed and held in a state of engagement with the annular groove 9a.
A device for preventing backflow and flashback of a gas body, which is characterized by forming a bow contact portion in which large diameter portions 12″ are connected and formed to allow protrusion to the outside. 2) A device having a gas inflow port. A side case 1 and an outlet side case 2 having an outflow port are connected to form a closed device main body, and a flame-extinguishing filter and a filter case 3 are fixed in the device main body, and a cylindrical inflow port of the inlet side case is connected. A check valve 8 having a ventilation hole 8' and equipped with an O-ring 10 is slidably fitted therein, and is always urged in the direction of closing the inlet by a spring installed between it and the filter case 6. A guide body 11 having a plurality of grooves (t, 11', . . . Annular concave Ff
A cutoff valve 9 having a diameter of 9a and an O-ring 10 mounted at one end is slidably fitted therein, and is always biased by a spring in the direction of closing the outlet, thereby causing the cutoff valve 9 to open when the flow out [1 open]. In order to maintain the condition, a ball 16 having a diameter larger than the depth of the hole is fitted into each hole 11' of the guide body 11 to
16 and the annular recess 9a of the cutoff valve 9 can be fitted and locked,
Historically, a pressure receiving ring 12 consisting of a flange portion 12b and a C'tI-shaped portion 12a that receives impact pressure at the time of flashback is slidably fitted on the outer periphery of the guide body 11, and a spring is used to prevent the outflow [
1: The inner surface of the i-shaped portion 12a is surrounded by an annular enclosure 1+'IY 9a.
A ball abutting part formed by connecting a small diameter part 12' to be pressed and held in a fitted and latched state with a large diameter part 12' that enables each of the balls to protrude outside the guide body 11. A device for preventing backflow of gas and flashback, characterized in that it is formed by forming.