JPH02102994A - Bimetal steam trap - Google Patents

Abstract

PURPOSE:To change the discharge temperature of a fluid following the inlet pressure and to easily detach a valve and a valve seat to facilitate maintenance by installing a cover member in such a manner as to partition between the valve seat and the interior of a valve chest to form a pressure changing room between the valve seat and the cover member, and placing a flat plate valve element in the free state to be pressed to the whole of the valve seat. CONSTITUTION:Condensate inflow passages 58a, b, c, d are formed for communicating a valve seat surface 56 with a valve chest 52, and a condensate outflow passage 60 is formed for communicating the valve seat surface 56 with an outlet 48. An inverted cup-like cover member 66 is threaded and connected on the upper portion of the valve seat surface 56 to form a pressure changing chamber 68 in the interior, thereby partitioning off the atmosphere in the valve chest. Bimetals 80, 82 are expanded by a high temperature and displaced in the axial direction of a valve shaft 72 to overcome inlet pressure, so that a valve element 70 is pressed to the valve seat surface 56 to close a valve. If the temperature of condensate in the valve chest is lowered by radiation, the bimetals 80, 82 are contracted to decrease the valve closing force applied to the valve element 70, and inlet pressure from the condensate inflow passages 58a, b, c, d works to open the valve element 70.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a steam trap that automatically discharges condensate generated in steam-using equipment such as a heat exchanger or steam piping, and particularly relates to a steam trap that automatically discharges condensate generated in steam-using equipment such as a heat exchanger or steam piping. This invention relates to a bimetallic steam trap that opens and closes a valve body to discharge condensate at a desired temperature to the outside of the vessel.

<Prior Art> Conventionally, there is a bimetallic type as shown in FIGS. 4 and 5.

The one in FIG. 4 is a raised type valve, in which the valve shaft 6 of the valve body 8 passes through the inside of the valve port 4 of the valve seat member 2, and the valve body 8 is connected to the valve port 4.
It is located on the exit side of the The bimetal 10.12 is arranged between the upper end of the valve seat member 2 and the locking member 14 at the upper end of the valve stem 6.

When the bimetal 10.12 expands due to the high temperature condensate, the valve stem 6 is pulled up and the valve element 8 closes the valve opening of the valve seat member 2, thereby acting to stop the flow of fluid.

The one in Figure 5 is a valve pressing method, and the valve port 2 of the valve seat 20
A bias spring 28 is arranged between the locking member 26 of the valve body 24 and the valve seat member 20, and a bimetal spring 28 is placed between the locking member 26 and the valve chamber wall. 3
Set 0.32.

The bimetal 30, 32 expands due to the high temperature condensate, overcomes the bias spring 28, displaces the valve body 24, closes the valve port 22, and stops the flow of fluid. When the condensate temperature falls, the bimetals 30 and 32 contract, and the bias spring 28 acts to open the valve port 22.

<Problems to be Solved by the Invention> The bimetallic steam traps described above each have the following problems.

In the one in Figure 4, the valve body 8 and valve stem 6 are inserted from the outlet side of the valve seat member 2, and the bimetal 10.12 is attached to the upper part of the valve stem 6 that has passed through it, so when replacing the valve , and maintenance work such as cleaning the inside of the trap is complicated.

5 has a structure in which the primary side pressure acts on the valve body 24 in the valve closing direction, so there is a problem that the opening temperature of the valve decreases as the downstream side pressure increases.

Therefore, the technical object of the present invention is to provide a bimetallic steam trap in which the opening temperature of the valve changes to follow changes in the downstream pressure, and which is easy to disassemble and assemble for maintenance. That's it.

Means for solving the above problems> The technical means of the present invention taken to solve the above problems are as follows:
An inlet and an outlet are formed in a valve casing that forms a valve chamber, a valve seat member is disposed within the valve chamber, the valve seat member has a flat valve seat on its upper surface, and a condensate valve that communicates with the valve seat and the inside of the valve chamber. An inflow passage and a condensate outflow passage communicating between the valve seat and the outlet are formed, and a lid member is attached to separate the valve seat and the valve chamber to form a variable pressure chamber between the valve seat and various members. A flat plate-shaped valve body is placed in a free state so as to come into contact with the body, and a bimetal that undergoes cardiac displacement at high temperatures is placed between the valve body and the inner wall of the lid member.

When the fluid that flows in from the inlet and accumulates in the valve chamber and the fluid that flows into the variable pressure chamber from the condensate inflow passage of the valve seat member are hot, the bimetal expands and presses the valve body against the valve seat, causing the condensate to flow out. Stop leakage into aisles. When the temperature of the fluid in the valve chamber decreases due to heat radiation, the bimetal also contracts accordingly, and the force with which it is pressed against the valve body decreases. When the pressure on the valve body decreases, the primary side pressure in the valve chamber acts to push the valve body up, and the condensate inflow passage and the condensate outflow passage of the valve seat member communicate, and the low-temperature fluid flows out to the outlet side. do.

When high-temperature fluid flows into the valve chamber due to the flow of fluid, the bimetal expands again, overcomes the pressure on the downstream side, and presses the valve element against the valve seat, closing the valve. Repeat this process to discharge low-temperature condensate.

Therefore, the fluid discharge temperature changes to follow the population pressure. In other words, the valve body is displaced due to the balance between the force and the inlet pressure when the bimetal is pressed, so even if the inlet pressure increases, the temperature of the fluid increases accordingly, the bimetal also expands, and the force that presses the valve body increases. Because it will make you stronger.

<Example> An embodiment showing the physical means of the present invention will be described.

(See FIGS. 1 to 3) The upper body 42 and the lower body 46 are fastened together with bolts 50 to form a valve casing 40 having a valve chamber 52 therein. A gasket 51 is interposed between the cylinder bodies to maintain airtightness between them.

An opening 44 is formed in the upper part of the upper body 42 and an outlet 48 is formed in the lower part of the lower body 46. The inlet 44 communicates with the upper part of the valve chamber 52 and is connected to steam-using equipment (not shown), etc. to supply condensate to the valve chamber 5.
Introduced within 2. A valve seat member 5 is installed on the valve chamber 52 side of the lower body 46.
4 are screwed together and a gasket 55 is used to maintain airtightness between the two. The upper end surface of the valve seat member 54 forms a flat valve seat surface 56, and the condensate inflow passage 5 communicates the valve seat surface 56 with the valve chamber 52.
Ba, b, c, d (see Figure 3), and the valve seat surface 56
A condensate outflow passage 60 communicating with the outlet 48 is formed. The port 44 and the outlet 48 open coaxially, and each has a female thread for piping.

The valve seat surface 56 is a circular plane, and the inner valve seat J 6 a * b
*c, d and an outer annular valve seat 56e, an annular groove 62 is formed between the inner valve seat and the annular valve seat, and communication grooves 64a, b
, C, and d communicate with the condensate outflow passage 60.

An inverted cup-shaped lid member 66 is screwed to the upper part of the valve seat surface 56 to form a variable pressure chamber 68 inside, which is separated from the atmosphere inside the valve chamber 52. Reference number 57 is a screen.

A disc-shaped valve body 70 is placed in a free state in the variable pressure chamber 68 so as to come into contact with the entire valve seat surface 56. The diameter of the valve body 70 is formed to be slightly smaller than the inner diameter of the lid member 60.
A valve shaft 72 is provided at the center of the upper surface of the valve shaft, a leaf spring 78 and a disc-shaped bimetal 80, 82 are arranged to pass through the shaft, and a locking member 74 is attached to the upper end of the valve shaft 72. The outer peripheral edge of the disc spring 78 is brought into contact with the ceiling inner wall of the lid member 66.

The operation of the above steam trap is as follows. At low temperatures at the beginning of ventilation, such as when steam-using equipment starts up, condensate flows into the valve chamber 52 from the inlet 44, passes through the screen 57, and enters the condensate inflow passages 58a, b, C, and 58a provided in the valve seat member 54.
Go through d and head to the transformation room. At this time, the condensate is at a low temperature, so the bimetal is contracted, and the valve body is in a free state. Therefore, the valve body is raised by the pressure on the inlet side and its jet flow to open the valve, and low-temperature condensate is discharged to the condensate outflow passage 60. (Situation shown in Fig. 2) High-temperature condensate flows into the valve chamber 52 as low-temperature condensate is discharged, passes through the lid member 66, and flows through the condensate inlets 58a, b, and C.
, d and enters the transformer chamber 68 to warm the bimetal. The bimetal expands due to high heat and is displaced in the axial direction of the valve shaft 72, overcoming the inlet pressure and moving the valve body 70 toward the valve seat surface 5.
6 to close the valve. (The state shown in Fig. 1) Then, when the temperature of the condensate in the valve chamber 52 decreases due to heat radiation, the bimetal 80, 82 contracts again and the valve closing force to the valve body 70 decreases, and the condensate inflow passage 5+8a, The inlet pressures from b, c, and d act to open the valve body 70 again.

Repeat this process to discharge low-temperature condensate.

As mentioned above, the valve body 70 is opened by the valve seat member 1 due to the balance between the force caused by the U5 cloth of the bimetal 80 and 82 and the pressure on the primary side that is always acting in the valve opening direction of the valve body. Even if the inlet pressure rises and attempts to open the valve body, the temperature of the fluid also rises, so the expansion force of the bimetal increases and acts to close the valve body. Therefore, it is possible to discharge condensate at a temperature corresponding to changes in inlet pressure.

What is important here is the inlet pressure and the condensate inflow passages 58a, b.
The product of the total area of , c, and d (force that tries to open the valve body)
must be designed so that it is always larger than the product of the pressure in the variable pressure chamber and the condensate discharge passage 60 (valve closing force of the valve element excluding the valve closing force due to the bimetal). If the inlet pressure leaks into the variable pressure chamber while the valve body is closed (the state shown in FIG. 1), the valve closing force will be greater and there is a risk that the valve body will not open. Therefore, as shown in FIG. 3, an annular valve seat 56e is provided.
The fluid that is about to leak in the direction from the annular groove 62 to the communication groove 6
4a, b, c, d to the condensate discharge passage 60,
Prevent fluid from flowing into the variable pressure chamber.

<Effects of the Invention> Since the inlet pressure always acts in the valve opening direction, the valve opening temperature also increases as the inlet pressure increases, making it possible to use it as a steam trap.

In addition, the valve and valve seat are easy to remove, making maintenance easy, and maintenance can be performed by simply rubbing the valve body together, as with conventional disc-type traps.

If the valve is pulled up, the valve opening cannot be used effectively because of the valve stem, but in the case of the present invention, there is no valve stem and it is possible to discharge the body.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of an embodiment of the present invention, Fig. 2 is an enlarged sectional view of the valve seat portion, Fig. 3 is a plan view of the valve seat surface, and Figs. 4 and 5 are conventional bimetallic steam generators. FIG. 3 is a cross-sectional view of the main parts of the trap. 42: Upper body 44: Hero 46: Lower body 48: Outlet 52: Valve chamber 54: Valve seat members 58a, b, c
, d: Condensate inflow passage 60: Condensate outflow passage 68: Variation chamber

Claims (1)

[Claims] 1. An inlet and an outlet are formed in a valve casing that forms a valve chamber, a valve seat member is arranged within the valve chamber, the valve seat member has a flat valve seat on its upper surface, and the valve seat communicates with the inside of the valve chamber. A condensate inflow passage and a condensate outflow passage communicating with the valve seat and the outlet are formed, and a cover member is attached to separate the valve seat and the valve chamber to form a variable pressure chamber between the valve seat and the cover member. A bimetallic steam trap in which a flat plate-shaped valve body is placed in a free state so as to contact the entire seat, and a bimetal that expands and displaces at high temperature is placed between the valve body and the inner wall of the lid member.