JPH0223595Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a rupture disc used for releasing excess pressure in various pressure devices, particularly in pressure storage tanks of tank containers and tank trucks.

[Conventional technology]

Rupture discs installed in storage tanks such as tank containers to release excess pressure generally have a dome-shaped rupture part, and are installed in the storage tank so that the pressure inside the storage tank is applied to the concave side of the rupture part. It will be done. Then, when the pressure exceeds the set bursting pressure,
The rupture portion is configured to rupture and release the pressure inside the storage tank to the outside.

The rupture disc is often used in conjunction with a safety valve, and in this case, the rupture disc is used as a means of protecting the safety valve. That is, the rupture disc is attached to the inlet side of the safety valve to prevent leakage of the stored substance from the safety valve, corrosion of the safety valve by the stored substance, and malfunction due to sticking of the safety valve caused by the viscosity of the stored substance.

Here, as shown in FIG. 5A, the conventional rupture disc 101 has a cutout groove 104 as a rupture line.
is formed, but this notch groove 10
4 was formed on the convex side, that is, the outer surface, of the rupture disc 101, and its outer ring was directly fixed to the periphery of the pressure opening.

[Problem that the invention attempts to solve]

The conventional rupture disc 101 shown in FIG. 5A is as follows:
When subjected to internal pressure (thick arrow), the notch groove 10
The convex surface on which the number 4 is formed receives a force (thin arrow) in the direction of extension, and the notched groove 104 advances inward. Therefore, the creep resistance is low and the internal pressure cannot be maintained, and the tensile strength decreases extremely over time and breaks early.
It cannot be used in locations subject to internal pressure above a certain level. In addition, it has the disadvantage that it cannot resist back pressure vacuum and collapses, so a vacuum support or the like is required.

In addition, since the outer ring is directly fixed to the periphery of the pressure opening, when it breaks, fragments may be torn off from the outer ring and scattered, damaging the seat of the safety valve or getting caught in the seat. There was a risk that the valve body of the safety valve would not be able to return to the closed state even after the pressure in the storage tank had decreased sufficiently.

[Purpose of invention]

This invention was developed to solve the above problems, and it ruptures accurately at the set bursting pressure, does not scatter fragments when it ruptures, and has the strength to withstand vacuum and back pressure on its own. The purpose is to provide rupture discs.

[Means for solving problems]

In order to solve the above-mentioned problems, the rupture disc of the present invention has a reinforcing seal ring closely covering the outer ring, and has a dome-shaped rupture part on the concave side where pressure is applied, and a rupture part when excessive pressure is generated. It is characterized in that a groove consisting of a concave groove is formed.

[Effect]

When internal pressure (thick arrow) is applied to the rupture disc of the present invention, as shown in FIG. 5B, the groove 4
is formed on the concave side, that is, the inner surface, so that the surface of the rupture disc receives a force in the direction of expansion, and at the same time the groove 4 receives a force in the direction of compression (thin arrow).
receive. Therefore, the creep resistance of the groove 4 is high and it is possible to maintain a constant normal internal pressure (85% of the set pressure), allowing continuous operation at normal operating pressure. Furthermore, the depth of the groove 4 does not change over time.

Furthermore, a reinforcing seal ring on the outer ring prevents fragments from scattering at the time of breakage.

〔Example〕

Examples of the present invention will be described below.

As shown in FIGS. 1 and 2, the rupture disc 1 of the embodiment is made of a thin plate of nickel, for example, and has a dome-shaped rupture part 2 and an outer ring part 3. As shown in FIG. 1, the concave side 2 which is the pressure receiving side of the rupture part 2
In a, notch grooves 4 consisting of four grooves are formed radially at 90° intervals. Although the cutout grooves 4 are formed by press working in this embodiment, they may be formed by, for example, cutting. Further, the shape and number of the notched grooves 4 can be variously determined depending on the set bursting pressure.

A reinforcing seal ring 7 consisting of both upper and lower ring members 5 and 6 is attached to the upper and lower surfaces 3a, 3b and the outer peripheral end surface 3c of the outer ring portion 3 of the rupture disc 1 so as to closely cover them. Further, the inner circumferential surface of the upper ring member 5 that is in contact with the upper surface 3a of the outer ring portion 3 has a rounded surface 8 around the entire lower corner.

Next, as shown in FIG. 3, the rupture disc 1 with the reinforcing seal ring 7 is inserted into the step 10 provided at the outlet 9 of the discharge nozzle through the packing P1, with the concave side 2a facing into the storage tank. and is fixed by a mounting flange 11.

The mounting flange 11 has a flange portion 13 for mounting protruding from the outer periphery of a cylindrical main body 12. The flange portion 13 is fixed to the storage tank side with bolts B, and is inserted into the stepped portion 10. Inserted main body 12
The lower end of the reinforcing seal ring 7 and the rupture disc 1 are pressed and fixed in an airtight manner. Also, mounting flange 1
A threaded portion 14 is formed on the inner circumferential surface of the upper end portion of the main body 12.

A valve seat 16 of a safety valve 15 is screwed into the threaded portion 14, and a disk-shaped valve body 17 is mounted on the seat surface of the valve seat 16, and two coils are interposed between the valve body 17 and the cover 18. They are pressed into airtight contact by springs S1 and S2. When a pressure exceeding the set blowing pressure due to the elasticity of the coil springs S1 and S2 is applied to the lower surface of the valve body 17, the valve body 17 floats upward and releases the excess pressure to the outside. It is configured.

Next, the operation of the configuration described above will be explained.

When the pressure inside the storage tank exceeds the set burst pressure, the rupture part 2 of the rupture disc 1 ruptures along the notch groove 4 toward the convex side (safety valve side), as shown in FIG. The opening is divided into four tongue-shaped pieces 19. Since the rupture part 2 opens along the pre-formed notch groove 4, complicated fragments are not generated when the rupture part 2 ruptures. In addition, since the lower corner of the inner peripheral surface of the upper ring member 5 is rounded,
The base of each tongue-like piece 19 that is turned upwards is not cut by the edge of the upper ring member 5 and scattered.

Then, pressure is applied to the lower surface of the valve body 17 of the safety valve 15, lifting the valve body 17 upward. The stored substance in the storage tank passes through the opening 20 of the rupture disc 1 and blows out from the gap between the valve body 17 and the valve seat 16, but as the pressure in the tank eventually decreases, the coil spring The valve body 17 is pressed against the valve seat 16 again by the elastic forces of S1 and S2, and the safety valve 15 returns to the closed state. At this time, if a fragment of the rupture disc 1 is caught on the seat surface of the safety valve 15, the safety valve 15 will not close, and the stored material will not stop blowing out even though the internal pressure has fallen below the set burst pressure. However, since the rupture disc 1 of this embodiment does not generate any fragments as described above, the safety valve 15 is reliably closed. Therefore, there is no needless release of stored substances, which is advantageous both economically and in terms of safety.

In addition, when manufacturing the rupture disc 1 of the embodiment, if the thickness of the material is set to a certain degree and the depth of the notch groove 4 is made deep, the overall strength is high but the set burst pressure value is small. It can be a board. Such a rupture disc does not require a reinforcing member such as a vacuum support, and can be used in places where back pressure is applied or where the back side is in a vacuum state.

[Effect of idea]

As explained above, according to the rupture disc of the present invention, the rupture disc ruptures accurately at the set rupture pressure, the depth of the groove 4 does not increase over time, and the rupture disc itself creates a vacuum pressure. It has the strength to withstand pressure and also has the advantage of not scattering fragments when it bursts.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention, FIG. 2 is a sectional view taken along the line - in FIG. FIG. 4 is a perspective view showing the rupture disc after rupture;
FIGS. 5A and 5B are cross-sectional views of essential parts illustrating the difference in function between the conventional rupture disc and the rupture disc of the present invention. 1... Rupture disk, 2... Rupture portion, 3a... Concave side, 4... Notch groove.

Claims (1)

[Scope of utility model registration request] A reinforcing seal ring is attached to closely cover the outer ring, and a groove is formed on the concave side of the dome-shaped rupture part where pressure is applied, which becomes the rupture part when excessive pressure is generated. Rupture disc.