JP2000205492A - Thermally actuated steam trap - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermally actuated steam trap capable of quickly discharging a large amount of low temperature fluid at the time of starting and certainly closing a lead-out passage. SOLUTION: An inlet 4, a valve chest 3 and an outlet 5 are formed of an upper casing 1 and a lower casing 2. A temperature control element 10 is arranged in the valve chest 3. The temperature control element 10 is formed by sealing an expansion medium 16 in an inner space 14 formed by fastening outer peripheral edges of a wall member 12 and a diaphragm 15 and connecting a valve member 18 to the diaphragm 15. A shape memory alloy 21 on end of which is fixed on the valve member 18 and the other end of which is fixed on a valve member 8 is provided. The temperature control element 10 is separated from the valve seat member 8 by energizing the valve member 18 in the valve opening direction at low temperature by the shape memory alloy 21, and at high temperature, the temperature control element 10 is held at a constant position in the valve chest 3 and the valve member 18 is energized in the valve closing direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam trap for automatically discharging condensate generated in various steam-using equipment and steam pipes, and more particularly, to a temperature including a medium which is heated, expanded, cooled, and contracted. The present invention relates to a heat-responsive steam trap for discharging a fluid having a temperature lower than a desired temperature out of a system by using a control element.

[0002]

2. Description of the Related Art A thermally responsive steam trap using a temperature control element is disclosed, for example, in Japanese Patent Application Laid-Open No. 8-86397. As understood from the publication, an inlet, a valve chamber, and an outlet are formed by casing, an expansion medium is sealed in an internal space formed by fixing a wall member and an outer peripheral edge of the diaphragm, and a valve member is mounted on the diaphragm. A connected temperature control element is disposed in a valve chamber, and a valve member is driven by displacement of a diaphragm due to expansion and contraction of an expansion medium to open and close an outlet path formed at an opening end of a valve chamber at an outlet. .
The expansion medium is formed of water, a liquid having a lower boiling point than water, or a mixture thereof.

[0003]

When a high-temperature fluid having a temperature equal to or higher than a predetermined temperature flows into the valve chamber, the expansion medium expands and the pressure in the internal space increases, and the diaphragm opposes the fluid pressure on the inlet side. The valve member is displaced in the valve closing direction to close the lead-out path. This prevents the discharge of steam. When a low-temperature fluid of a predetermined temperature or less flows, the expansion medium contracts and the pressure in the internal space drops, and the diaphragm is displaced in the valve opening direction by the fluid pressure on the inlet side, and the valve member opens the outlet passage. . As a result, condensate and air are discharged out of the system.

[0004] However, such a thermo-responsive steam trap has a problem that it takes time to discharge a large amount of low-temperature fluid accumulated at the time of starting. This is because the expansion medium is contracted at the time of starting, the valve member is separated from the valve seat member and the outlet path is opened, but since the gap between the valve member and the valve seat member is narrow, a large amount of This is because it takes time to discharge the low-temperature fluid.

Further, when water, a liquid having a boiling point slightly lower than that of water, or a mixture thereof is used as the expansion medium, there has been a problem that the outlet path cannot be completely closed and steam leakage occurs. this is,
This is because the pressure in the internal space that rises due to the expansion of the expansion medium is equal to or slightly higher than the fluid pressure on the inlet side, and the valve closing force for closing the outlet path is weak. .

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a heat-responsive steam trap which can quickly discharge a large amount of low-temperature fluid at the time of starting and can reliably close an outlet passage.

[0007]

In order to solve the above technical problems, the technical means of the present invention is to form an inlet, a valve chamber, and an outlet by casing, and to form an outer peripheral edge of a wall member and a diaphragm. A temperature control element having a valve member connected to a diaphragm is arranged in a valve chamber, and the valve member is driven by displacement of the diaphragm due to expansion and contraction of the expansion medium, and an outlet is provided. Opening and closing a lead-out passage formed at the valve chamber side opening end of the temperature control element by urging the diaphragm or the valve member in the valve opening direction at a low temperature between the diaphragm or the valve member and the valve seat member or the casing. And a temperature responsive member for biasing the diaphragm or the valve member in the valve closing direction while maintaining the temperature control element in a fixed position in the valve chamber at a high temperature. In Mutorappu - thermally responsive type steel to symptoms.

[0008]

DETAILED DESCRIPTION OF THE INVENTION In a thermally responsive steam trap according to the present invention, a temperature responsive member disposed between a diaphragm or a valve member and a valve seat member or a casing attaches the diaphragm or the valve member in a valve opening direction at a low temperature. The temperature control element is moved away from the valve seat member to maintain the temperature control element at a fixed position in the valve chamber at the time of high temperature and to urge the diaphragm or the valve member in the valve closing direction. Therefore, at the time of startup in which the temperature inside the valve chamber is low, the temperature responsive member separates the temperature control element from the valve seat member, so that a sufficient discharge flow path can be secured between the valve member and the valve seat member, and a large amount of low temperature Fluid can be quickly drained. Also, when the temperature inside the valve room becomes high,
Since the temperature responsive member urges the diaphragm or the valve member in the valve closing direction, this urging force is applied as a force for closing the lead-out path, and the lead-out path can be reliably closed, thereby preventing steam leakage.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment showing a specific example of the above technical means will be described (see FIG. 1). Upper case 1 and lower case 2
Are screwed together to form a casing having a valve chamber 3 therein. The upper case 1 has an inlet 4 and the lower case 2 has an outlet 5. The inlet 4 and the outlet 5 are formed coaxially. A valve seat member 8 having an outlet 7 communicating the valve chamber 3 and the outlet 5 is screwed to the transverse wall 6 of the lower casing 2.

A temperature control element 10 is disposed above the valve seat member 8. The temperature control element 10 includes a wall member 12 having an inlet 11, a plug member 13 for sealing the inlet 11, and a diaphragm 15 forming an internal space 14 between the wall member 12.
And an expansion medium 16 sealed in the internal space 14, a valve member 18 fixed to the diaphragm 15 by welding (reference numeral 17), and an outer peripheral edge of the diaphragm 15 to the wall member 1.
2 and a lower wall member 20 fixed by welding (reference numeral 19). The expansion medium 16 includes water,
It is formed of a liquid having a lower boiling point than water, or a mixture thereof.

One end of a coil-shaped shape memory alloy 21 as a temperature responsive member is fixed to the valve member 18 and the other end is fixed to the valve seat member 8. One end of the shape memory alloy 21 may be fixed to the diaphragm 15. The other end is the lower casing 2
May be fixed. The shape memory alloy 21 contracts at a high temperature, and holds the lower surface outer periphery of the lower wall member 20 of the temperature control element 10 against the steps of the plurality of ribs 22 formed on the inner periphery of the lower casing 2. At the same time, the valve member 18 is urged in the valve closing direction (toward the valve seat member 8). Also, the shape memory alloy 21 extends at low temperatures, displacing the temperature control element 10 upward,
The outer periphery of the lower surface of the lower wall member 20 is separated from the steps of the plurality of ribs 22. Reference numeral 23 denotes a screen fixed between the upper case 1 and the lower case 2 for capturing foreign matter.

The operation of this embodiment is as follows. At the time of startup, the temperature in the valve chamber 3 is low, and the shape memory alloy 21 expands to displace the temperature control element 10 upward, and the lower wall member 20
Is separated from the stepped portions of the plurality of ribs 22.
The expansion medium 16 is contracted. Therefore, the valve member 1
A sufficient discharge flow path can be secured between the valve member 8 and the valve seat member 8, and a large amount of low-temperature fluid can be discharged quickly.

When the temperature of the fluid flowing into the valve chamber 3 increases due to the discharge of the low-temperature fluid, the shape memory alloy 2
1 is shrunk to hold the outer periphery of the lower surface of the lower wall member 20 of the temperature control element 10 against the steps of the plurality of ribs 22 formed on the inner periphery of the lower casing 2 and to hold the valve member 18. In the valve closing direction (toward the valve seat member 8). Then, when the temperature of the fluid flowing into the valve chamber 3 further increases, the expansion medium 16 expands. The valve member 18 is seated on the valve seat member 8 by the deformation force that urges the valve member 18 of the shape memory alloy 21 in the valve closing direction and the pressure in the internal space that rises due to the expansion of the expansion medium, and the outlet path 7 is closed. I do. This prevents vapor leakage. As described above, since the deformation force of the shape memory alloy 21 is applied as the valve closing force, the lead-out path 7 can be reliably closed.

When the fluid temperature in the valve chamber 3 decreases due to heat radiation or the like, the expansion medium 16 contracts, and the valve member 18 separates from the valve seat member 8 to open the outlet passage 7. Thereby, low-temperature condensate and air are discharged from the outlet 5.

[0015]

The present invention has the following specific effects. As described above, the present invention provides a method in which the temperature control element is separated from the valve seat member by pressing the diaphragm or the valve member in the valve opening direction at a low temperature between the diaphragm or the valve member and the valve seat member or the casing at the time of a low temperature, and at a high temperature. The temperature control element is held in a fixed position in the valve chamber, and a temperature responsive member that biases the diaphragm or valve member in the valve closing direction is provided. An excellent effect of being able to close is produced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a thermally responsive steam trap according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper casing 2 Lower casing 3 Valve room 4 Inlet 5 Outlet 7 Outgoing path 8 Valve seat member 10 Temperature control element 12 Wall member 14 Internal space 15 Diaphragm 16 Expansion medium 18 Valve member 21 Shape memory alloy

Claims (1)

[Claims] A temperature control wherein an inlet, a valve chamber, and an outlet are formed by casing, an expansion medium is sealed in an internal space formed by fixing a wall member and an outer peripheral edge of the diaphragm, and a valve member is connected to the diaphragm. A device in which a valve element is disposed in a valve chamber and a valve member is driven by displacement of a diaphragm due to expansion and contraction of an expansion medium to open and close an outlet path formed at an opening end of a valve chamber at an outlet. At a low temperature, the diaphragm or the valve member is urged in the valve opening direction to separate the temperature control element from the valve seat member between the members or the casing. Alternatively, a thermally responsive steam trap provided with a temperature responsive member for urging the valve member in a valve closing direction.