JP4717248B2 - Disc type steam trap - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a disk-type steam trap that automatically discharges condensate generated in various steam-using devices and steam pipes by using a valve disk that opens and closes in response to a pressure change in a variable pressure chamber, that is, a thermodynamic steam chamber. In particular, the present invention relates to a high temperature and high pressure steam system (generally 16 kg / cm 2 in a steam trap, 220 ° C. or more).
[0002]
The basic configuration of the disc type steam trap is that a lid is fixed to a main body having an inlet and an outlet to form a variable pressure chamber inside, and an outlet hole is formed in the center of the variable pressure chamber so that the inlet and the variable pressure chamber communicate with each other. An annular groove that opens to the outer periphery of the ejection hole is provided, an inner ring valve seat is formed between the ejection hole and the annular groove, and an outer ring valve seat that is flush with the inner ring valve seat is formed on the outer periphery of the annular groove. , A discharge hole is provided in the annular groove, the transformation chamber communicates with the outlet, and a disk-shaped valve disk that is attached to and detached from the inner ring valve seat and the outer ring valve seat is disposed in the transformation chamber. It is controlled in a self-powered manner by pressure change and is seated on the inner ring valve seat and the outer ring valve seat, and the condensate is automatically discharged. When this disk-type steam trap is used in a high-temperature and high-pressure steam system, there is a problem that a slight gap is formed between the valve disk and the inner ring valve seat, and the steam leaks. This is because when the valve is closed, a high-temperature and high-pressure inlet-side pressure acts at the center of the bottom surface of the valve disk, and the pressure of the variable pressure chamber acts on the top surface of the valve disk, so that the valve disk curves upwardly, This is because a slight gap is formed between the outer ring valve seat and the inner ring valve seat.
[0003]
[Prior art]
Therefore, conventionally, a technique as disclosed in Japanese Patent Publication No. 59-7078 has been used. This is because the inner and outer ring valve seats are made of different metals so that the thermal expansion of the inner ring valve seats is greater than that of the outer ring valve seats, and the inner ring valve seats are made higher than the outer ring valve seats. Even when the valve disk is curved upwardly at the time of valve operation, the valve disk can be in close contact with the inner ring valve seat and the outer ring valve seat.
[0004]
[Problems to be solved by the invention]
In the conventional disc type steam trap, the valve disc can be kept in close contact with the inner ring valve seat and the outer ring valve seat immediately after the valve is closed, but the pressure between the outer ring valve seat and the valve disc is reduced as the pressure in the variable pressure chamber decreases. Since a slight gap is generated, there is a problem that the fluid in the variable pressure chamber is discharged to the outlet and the valve is opened relatively early. This is because the pressure drop in the variable pressure chamber, which is shut off from the inlet, is faster than the temperature drop in the injection hole communicating with the inlet, and the decrease in the degree of curvature of the valve disc is greater than the decrease in the degree of thermal expansion of the inner ring valve seat. In addition, although the valve disk is in close contact with the inner ring valve seat, a slight gap is formed between the valve disk and the outer ring valve seat. Therefore, the technical problem of the present invention is to provide a disc type steam trap which does not discharge the fluid in the variable pressure chamber until the valve disc is separated from the inner ring valve seat.
[0005]
[Means for Solving the Problems]
The technical means of the present invention devised to solve the above technical problem is that a lid is fixed to a main body having an inlet and an outlet to form a variable pressure chamber therein, and an ejection hole that opens at the center of the variable pressure chamber An annular groove that opens to the outer periphery of the ejection hole is provided, an inner ring valve seat is formed between the ejection hole and the annular groove, and an outer ring valve seat is formed around the outer circumference of the annular groove. Is formed with a discharge hole from the annular groove to communicate the variable pressure chamber and the outlet, and a disc-shaped valve disk that is attached to and detached from the inner ring valve seat and the outer ring valve seat is arranged in the variable pressure chamber. In comparison, the inner and outer ring valve seats are made of dissimilar metals so that the thermal expansion of the inner ring valve seat is increased, and a seal ring that slides on the outer circumferential wall of the annular groove is arranged in the annular groove. a spring as an elastic member for slightly protruded than the outer ring valve seat to an upper end of a bottom wall of the annular groove In which it provided between the lower surface of Ruringu.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, the inner and outer ring valve seats are formed of different metals so that the thermal expansion of the inner ring valve seat is larger than that of the outer ring valve seat, and the seal ring that slides the outer peripheral wall of the annular groove is disposed in the annular groove. A spring as an elastic member that slightly protrudes the upper end of the seal ring from the outer ring valve seat when the valve disk is opened is provided between the bottom wall of the annular groove and the lower surface of the seal ring . Therefore, immediately after the valve is closed, the valve disk is in close contact with the inner ring valve seat, the outer ring valve seat, and the seal ring against the biasing force of the spring as an elastic member. If a slight gap is created between the valve disc and the outer ring valve seat due to the pressure drop in the variable pressure chamber, the seal ring maintains close contact with the valve disc by the biasing force of the spring as an elastic member , and the fluid in the variable pressure chamber is discharged. do not do. Then, after the pressure in the variable pressure chamber is reduced to a predetermined valve opening pressure, the valve disc is separated from the inner ring valve seat and the seal ring and opened.
[0007]
【Example】
An embodiment showing a specific example of the above technical means will be described (see FIG. 1).
A lid 2 is screwed to the main body 1 to form a variable pressure chamber 3 therein. An inlet 4 and an outlet 5 are formed on the main body 1 on substantially the same axis. The main body 1 is provided with a jet hole 6 that opens at the center of the variable pressure chamber 3, and the inlet 4 and the variable pressure chamber 3 are communicated with each other through the jet hole 6. An annular groove 8 is provided on the outer periphery of the ejection hole 6, an annular inner ring valve seat 9 is formed between the ejection hole 6 and the annular groove 8, and an inner ring is formed concentrically with the inner ring valve seat 9 on the outer periphery of the annular groove 8. An annular outer ring valve seat 10 that is slightly lower than the valve seat 9 is formed. The outer ring valve seat 10 is formed integrally with the main body 1, and the inner ring valve seat 9 is formed of a metal having a higher thermal expansion coefficient than the outer ring valve seat 10 and is joined to the main body 1. The inner ring valve seat 9 may be integrally formed with the main body 1, and the outer ring valve seat 10 may be formed of a metal having a smaller coefficient of thermal expansion than the inner ring valve seat 9 and joined to the main body 1. Alternatively, the inner ring valve seat 9 and the outer ring valve seat 10 formed of a metal having a smaller thermal expansion coefficient than the inner ring valve seat 9 may be formed separately from the main body 1 and joined to the main body 1. The end of the annular groove 8 communicates with the outlet 5 through the discharge hole 7. A disc-shaped valve disk 11 that opens and closes to the inner ring valve seat 9 and the outer ring valve seat 10 to open and close is disposed in the variable pressure chamber 3 in a free state.
[0008]
A seal ring 12 that slides on the outer peripheral wall of the annular groove 8 is disposed in the annular groove 8, and the upper end of the seal ring 12 is opened between the bottom wall of the annular groove 8 and the lower surface of the seal ring 12 when the valve disk 11 is opened. A ring-shaped wave spring 13 is disposed as an elastic member that slightly protrudes from the outer ring valve seat 10. The seal ring 12 maintains close contact with the valve disk 11 by the biasing force of the wave spring 13 when a slight gap is generated between the valve disk 11 and the outer ring valve seat 10 due to a pressure drop in the variable pressure chamber.
[0009]
Next, the operation will be described. When steam does not stay in the variable pressure chamber 3, the valve disk 11 is separated from the inner and outer ring valve seats 9 and 10 due to the fluid pressure on the inlet 4 side acting on the valve disk 11 through the ejection holes 6, and the temperature is low. Condensate is discharged to the outlet 5 through the annular groove 8 and the discharge hole 7.
[0010]
When the condensate is discharged and steam flows into the variable pressure chamber 3, the pressure in the variable pressure chamber 3 rises, and high-speed steam flows down the bottom surface of the valve disk 11 to reduce the static pressure. The valve disk 11 is seated on the inner ring valve seat 9, the outer ring valve seat 10 and the seal ring 12 against the urging force of the wave spring 13 and is closed.
[0011]
When the steam in the variable pressure chamber 3 condenses due to heat dissipation or the like and the steam pressure decreases, the valve disk 11 creates a slight gap with the outer ring valve seat 10 as shown in FIG. However, the urging force of the wave spring 13 maintains close contact with the valve disk 11 and does not discharge the fluid in the variable pressure chamber 3. Then, after the pressure in the variable pressure chamber 3 is lowered to a predetermined valve opening pressure, the valve disk 11 is separated from the inner ring valve seat 9 and the seal ring 12 and opened. The above open / close valve cycle is repeated.
[0012]
【The invention's effect】
As described above, according to the present invention, even if a slight gap is generated between the valve disk and the outer ring valve seat, the seal ring maintains close contact with the valve disk and does not discharge the fluid in the variable pressure chamber. It is possible to prevent the valve from opening. Therefore, an excellent effect is obtained that frequent open / close valves can be prevented and the life can be extended.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an embodiment of a disc type steam trap of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Main body 2 Lid 3 Transformer chamber 4 Inlet 5 Outlet 6 Ejection hole 7 Ejection hole 8 Annular groove 9 Inner ring valve seat 10 Outer ring valve seat 11 Valve disk 12 Seal ring 13 Wave spring

Claims (1)

A lid is fixed to the main body having an inlet and an outlet to form a variable pressure chamber inside, and an injection hole that opens at the center of the variable pressure chamber is provided so that the inlet and the variable pressure chamber communicate with each other. A groove is provided to form an inner ring valve seat between the ejection hole and the annular groove, an outer ring valve seat is formed around the outer periphery of the annular groove, a discharge hole is provided from the annular groove, and the variable pressure chamber communicates with the outlet. A disc-shaped valve disc that is attached to and detached from the inner ring valve seat and the outer ring valve seat is disposed in the transformer chamber.The inner and outer ring valve seats are made of different metals so that the thermal expansion of the inner ring valve seat is larger than that of the outer ring valve seat. A seal ring that slides on the outer circumferential wall of the annular groove is arranged in the annular groove, and a spring as an elastic member that projects the upper end of the seal ring slightly from the outer ring valve seat when the valve disk is opened is annular. disc, characterized in that provided between the lower surface of the bottom wall and the seal ring groove Shikisu Mutorappu.

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