JPH0539294Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field]

The present invention relates to a dry type backflow flashback preventer for preventing backflow flashback of flammable gas.

[Conventional technology]

When flammable gas and oxygen are mixed and combusted, there is always a risk of backfire. This backfire is
This occurs when the flow rate of the mixed gas ejected from the combustion port and the combustion speed are not balanced due to, for example, the state of residual gas in the hose at the start of the operation, insufficient valve opening, or the crater is blocked. If the explosion caused by backfire reaches the pipes or containers, it will cause a major accident. Most of these flashback accidents are caused by hoses bursting, including those on the oxygen side. Therefore, it is a good idea to install a backflow flashback preventer near the flashback source to minimize the risk of accidents. be. For this purpose, for example, when a fuser 5 as shown in FIG. 7 is provided, a dry backflow flashback preventer 1 has been proposed that is attached to the connection portion of the fuser 5 to the hose 6. As shown in FIG.
a cylindrical second body 11 that is threadedly connected to one end in the axial direction of the body 10; a ring-shaped flame-extinguishing filter 12 that is disposed inside the second body 11; It consists of a check valve 13 located on the inner peripheral side and in contact with the second body 11 under the force of a spring 14, and a body 18 disposed inside the body 10, and the combustible gas or oxygen is It enters the interior through the inlet provided on the main body 11 side, opens the check valve 13 against the spring 14, passes through the flame-extinguishing filter 12, and the outer circumferential surface of the flame-extinguishing filter 12 and the inner circumferential surface of the second body 11. A through hole 16 that reaches the gap between the two and then passes through the main body 10
, and exits to the outlet on the main body 10 side. When a backflow flashback occurs, the flame extinguishing filter 12 stops the backflow of flame, and the check valve 1
3 also prevents backflow of gas or oxygen.

[Problem that the idea aims to solve]

However, the conventional backflow flashback preventer 1 of this type is
In order to incorporate the flame-extinguishing filter 12 and the check valve 13 as described above, the second body 1 is provided in addition to the main body 10.
1, and the two must be combined, resulting in a large number of parts and the effort required for assembly. The present invention has been devised in view of these points, and its purpose is to provide a backflow flashback preventer that requires a small number of equipment and is easy to assemble.

[Means to solve the problem]

Therefore, the present invention has a cylindrical main body that has an inlet at one end and an outlet at the other end, and the inner diameter on the inlet side is smaller than the inner diameter on the outlet side.
This body consists of a filter holder, a flame-extinguishing filter, and a spring-loaded check valve inserted into the body from the outlet side of the body, and the check valve and the flame-extinguisher are placed between the inner wall of the body on the inlet side. The filter holder that positions the filter has a through hole that communicates the inlet side and the outlet side, and has a pressed part on the outlet side that is pressed by coming into contact with a device connected to the outlet of the main body. The flame-extinguishing filter is sandwiched and fixed between the filter holder and the main body, and is located in the flow path between the through hole and the inlet. [Function] According to the present invention, assembly can be carried out by simply inserting each member into the main body from the outlet side of the main body. Once the gas-using equipment is connected, the filter holder and the flame-extinguishing filter receive the pressure from the gas-using equipment, eliminating gaps between each part, so there are no problems in actual use. [Example] The present invention will be described in detail below based on the illustrated example. As shown in FIG. filter holder 15 and ring-shaped anti-inflammatory filter 1
2, and a check valve 13 which is biased by a spring 14. The main body 10 has an inlet at one end and an outlet at the other end, and has a male thread 10 on the outer peripheral surface of the inlet.
A has a female thread 10b formed on the inner peripheral surface of the outlet side, and the inner diameter of the outlet side is larger than the inner diameter of the inlet side, and a check valve 13 is attached to one end side. It is larger than the maximum diameter of the filter holder 15 and the flame-extinguishing filter 12. That is, the flame-extinguishing filter 12 and the filter holder 15 can be inserted into the main body 10 from its outlet side. and a filter presser 1 equipped with a check valve 13;
5 and the quenching filter 12 from the outlet side of the main body 1.
When inserted into the check valve 13, the check valve 13 is biased by the spring 14, and the O-ring 13a attached to its tip contacts the small diameter portion of the main body 10 on the inlet side, thereby closing the flow path. The flame-retardant filter 12 has one end surface attached to the main body 10 and the other end surface attached to the filter holder 15, respectively.
2b. Additionally, a filter presser 1 having a through hole 16 is provided.
An O-ring 17 is disposed between the outer peripheral portion of the main body 18 integrally formed on the other end side of the main body 10 and the inner peripheral surface of the main body 10 on the outlet side. Now, the backflow flashback preventer 1 formed in this way
In this case, the filter retainer 15 is simply inserted into the main body 10 and is temporarily prevented from coming off by the O-ring 17, but the backflow flashback preventer 1 is melted down as shown in FIG. 2, for example. When connected to the filter holder 5, the tail portion 50, which is threadedly connected to the female thread 10b of the main body 10, presses the O-ring 17 and the main body 18, so that the filter holder 15 with which the main body 18 is integrally formed presses the O-ring 17 and the main body 18. is pushed into the main body 10, and both end surfaces of the flame-extinguishing filter 12 are securely brought into contact with the inner surface of the main body 10 and the filter holder 15 via the gaskets 12a and 12b, respectively, to eliminate the gap between them. There is no problem in actual use. Incidentally, the male thread 10a and the female thread 10b are right-handed threads for oxygen use and left-hand threads for gas use. Further, other members are the same for both oxygen and gas use. Another embodiment is shown in FIG. This shows a case where the connection to the hose on the inflow port side is made through the plug 20, and the main body 10
The plug 20, which is formed separately from the main body 10, is inserted into the main body 10 from the outlet side of the main body 10, is positioned by contacting the inner surface of the small diameter part on the inlet side of the main body 10, and is further positioned at the outlet of the main body 10. The pressing force of the filter holder 15 obtained when the side is connected to gas-using equipment is applied to the plug 20 through the flame-extinguishing filter 12.
The flange portion of the plug 20 is pressed against the wall surface of the small diameter portion on the inlet side of the main body 10 to eliminate the gap between the plug 20 and the main body 10. The one shown in FIG. 4 is for oxygen use, and the only difference is that the outer diameter of the plug 20 is different and that the female thread 10b of the main body 10 is a right-hand thread or a left-hand thread. This is common to the one for gas shown in Figure 3. Here, the plug 20 is formed separately from the main body 10 so that the main body 10 can be used in common with other products, but the main body 1
Of course, the plug 20 and the plug 20 may be integrally formed. Figure 5 shows check valve 13
Here are some other examples of shapes. Now, after connecting a hose or the like to the inlet side and supplying oxygen or gas, as shown in FIG.
After passing through, it passes through the space between the flame-extinguishing filter 12 and the inner peripheral surface of the main body 10 and the through hole 16 formed in the filter holder 15, and exits to the outlet side. As shown in FIG. 6b, the check valve 13 is closed by the force of the spring 14, and the flame-extinguishing filter 12 prevents the flame from flowing back.

[Effect of the idea]

As described above, in this invention, by inserting the filter holder, flame-retardant filter, and check valve into the main body from the outlet side of the main body, and connecting the outlet side of the main body to gas-using equipment, gas can be used. Each of the above-mentioned members is positioned and fixed by the pressing force applied from the device side, and there is no need for the second main body etc. shown in the conventional example, and a small number of parts can be used. There is no need to perform time-consuming installation such as screwing and fixing each member arranged in the assembly, and the time and effort required for assembly can be significantly reduced.

[Brief explanation of drawings]

Fig. 1 is a cutaway side view of one embodiment of the present invention, Fig. 2 is a cutaway side view showing the same usage condition, Fig. 3 is a cutaway side view of another embodiment, and Fig. 4 is a cutaway side view of another embodiment. A broken side view, FIG. 5 is a broken side view of another example, FIGS. 6 a and b are schematic sectional views showing the operation of the above, FIG. 7 is a piping diagram showing the above in use, and FIG. 8 is a conventional example. , in which 1 is a backflow flashback preventer, 10 is a cutaway side view of
is the main body, 12 is the flame-retardant filter, 13 is the check valve,
14 is a spring, and 15 is a filter holder.

Claims (1)

[Scope of utility model registration request] A cylindrical body that has an inlet at one end and an outlet at the other end, and the inner diameter of the inlet side is smaller than the inner diameter of the outlet side, and is inserted into the body from the outlet side of the main body. The filter holder consists of a disposed filter holder, an extinguishing filter, and a spring-biased check valve. and a through hole that communicates with the outlet side, and a pressed part on the outlet side that comes into contact with and is pressed by a device connected to the outlet of the main body,
A backflow flashback preventer characterized in that a flame-extinguishing filter is clamped and fixed between a filter holder and a main body and is located in a flow path between the through hole and the inlet.