JP2001263588A - Thermally-actuated steam trap - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermally-actuated steam trap capable of quickly discharging a large mount of low pressure condensate. SOLUTION: A casing is formed by fastening covers 4, 5 to a main body 3 having an inlet 1 and an outlet 2. A valve chamber 6 is formed between the main body 3 and the cover 4, and a valve seat storing chamber 7 is formed between the main body 3 and the cover 5. The valve chamber 6 and the valve seat storing chamber 7 are communicated through an opening 10 having a large passing area. In the valve seat storing chamber 7, a valve seat 15 provided with a valve hole 13 communicating the valve chamber 6 and an outflow passage 12 is arranged so as to move forward and backward. An inlet chamber 16 communicating from the inlet 4 through a communicating passage 9 is formed on the back surface of the valve seat 15, a first thermally-actuating element 17 is disposed in the inlet chamber 16. The first thermally-actuating element 17 is made of a coil-shaped shape-memory alloy, and shrinks at low temperature period to increase the passing area of the opening 10 by the valve seat 5, and throttles the passing area of the opening 10 by the valve seat 15 at high temperature period. The throttled passing area of the opening 10 is formed in a size that slightly leaves condensate generated at high temperature period without discharging. A second thermally-actuating element 19 is disposed in the valve chamber 6. The second thermally-actuating element 19 opens/closes the valve hole 13 at high temperature period when the valve seat 15 throttles the passing area of the opening 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-responsive steam trap which automatically discharges condensate generated in various steam-using equipment and steam piping by opening and closing a valve hole using a heat-responsive element. In particular, it relates to one having a large condensate discharge capacity.

[0002]

2. Description of the Related Art A thermally responsive steam trap using a thermally responsive element is disclosed, for example, in Japanese Patent Application Laid-Open No. 7-253194. As understood from the publication, a valve chamber is formed in a casing having an inlet and an outlet, a valve seat having a valve hole communicating the valve chamber and the outlet is provided, and a thermally responsive element that opens and closes the valve hole is provided by a valve. An orifice is provided in a communication passage that is disposed indoors and communicates with an inlet and an outlet.

[0003]

The above-mentioned conventional thermo-responsive steam trap has a condensate discharge capacity by normally opening an orifice connecting an inlet and an outlet separately from a valve hole opened and closed by a thermo-responsive element. However, since the passage area of the orifice is constant, it takes time to discharge the condensate, especially when a large amount of low-temperature drain is generated, such as during initial startup of the piping system. There was a problem to say.

Accordingly, it is an object of the present invention to provide a thermo-responsive steam trap capable of quickly discharging a large amount of low-temperature condensate.

[0005]

Means for Solving the Problems In order to solve the above technical problems, the technical means of the present invention is to form a valve chamber in a casing having an inlet and an outlet, and to communicate the valve chamber with the outlet. An opening with a large passage area is provided, and a valve seat provided with a valve hole communicating the valve chamber and the outlet is disposed so as to be displaceable facing the opening, and the passage area of the opening is lowered at a low temperature in response to the fluid temperature on the inlet side. A heat-responsive steam trap characterized in that a first heat-responsive element is connected to a valve seat so as to be enlarged and squeezed at a high temperature, and a second heat-responsive element for opening and closing a valve hole is disposed in a valve chamber.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In a heat-responsive steam trap according to the present invention, when a fluid temperature at an inlet side is low, a valve seat passes through an opening by a first temperature-responsive member responsive to a fluid temperature at an inlet side. The area is enlarged. Thereby, a large amount of low-temperature condensate is quickly discharged from the opening having a large passage area.
When the fluid temperature on the inlet side is high, the valve seat narrows the passage area of the opening. The passage area of the narrowed opening is such that the condensate generated at high temperature cannot be discharged completely. And the 2nd thermoresponsive element arranged in a valve room opens and closes a valve hole by the heat sensing effect. As described above, when the temperature is low, the condensate is discharged from the opening having a large passage area, so that a large amount of low-temperature condensate can be quickly discharged.

[0007]

An embodiment showing a specific example of the above technical means will be described (see FIG. 1). Lids 4 and 5 are fastened to a main body 3 having an inlet 1 and an outlet 2 to form a casing.
A valve chamber 6 is formed between the main body 3 and the lid 5, and a valve seat housing chamber 7 is formed between the main body 3 and the lid 5. The inlet 1 and the valve chamber 6 communicate with each other through an inlet passage 8,
The inlet 1 and the valve seat accommodating chamber 7 communicate with each other through a communication passage 9, the valve chamber 6 and the valve seat accommodating chamber 7 communicate with each other through an opening 10 having a large passage area, and the valve seat accommodating chamber 7 and the outlet 2 flow out. It communicates through the passage 12.

A valve seat 15 provided with a valve hole 13 for communicating the valve chamber 6 with the outflow passage 12 is disposed in the valve seat accommodating chamber 7 so as to be able to advance and retreat. An inlet chamber 16 communicating with the inlet 4 via the communication passage 9 is formed on the back surface of the valve seat 15, and the first heat responsive element 17 is disposed in the inlet chamber 16. The first thermal response element 17 is a coil-shaped shape memory alloy, and both sides thereof are connected to the valve seat 15 and the lid 5, respectively, and contracts at a low temperature to displace the valve seat 15 toward the lid 5 so that the valve seat 5 is displaced. The passage area of the opening 10 is increased, and the passage area of the opening 10 is narrowed by the valve seat 15 extending at a high temperature to displace the valve seat 15 toward the lid 5. The passage area of the squeezed opening 10 is formed to a size such that the condensed water generated at a high temperature cannot be completely discharged.

A second thermally responsive element 19 is arranged in the valve chamber 6. The second thermoresponsive element 19 includes an upper wall member 20 and an upper wall member 2.
A diaphragm 22 forming an internal space 21 between the diaphragm 22
An expansion medium 23 sealed in the internal space 21, a valve member 24 fixed to the diaphragm 22, a lower wall member 25 fixed with the outer peripheral edge of the diaphragm 22 sandwiched between the upper wall member 20, and an upper wall member 20 is constituted by a spring 26 for urging downward. The expansion medium 23 is formed of water, a liquid having a boiling point lower than that of water, or a mixture thereof.

The second thermal response element 19 has a valve seat 15 with an opening 10
The valve hole 13 is opened and closed at a high temperature with a narrow passage area. The valve chamber 6 is connected to the outlet passage 1 through the opening 10 having a large passage area at a low temperature.
2, and communicates with the outlet 2 via the outlet passage 12 from the opening 10 and the opened valve hole 13 having a narrow passage area at high temperature.

The operation of the thermally responsive steam trap of the above embodiment is as follows. When the fluid temperature on the inlet 1 side is low, the first heat responsive element 17 contracts to displace the valve seat 15 toward the lid 5, and the valve seat 15 increases the passage area of the opening 10. Thereby, a large amount of low-temperature condensate is quickly discharged from the opening 10 having a large passage area to the outlet 2.

When the fluid temperature on the inlet 1 side is high,
The first thermally responsive element 17 extends to displace the valve seat 15 toward the valve chamber 6, and the valve seat 15 narrows the passage area of the opening 10.
The passage area of the narrowed opening 10 is large enough not to completely discharge condensate generated at high pressure. And the second
The thermoresponsive element 19 closes the valve hole 13 when the temperature inside the valve chamber 3 increases due to its heat-sensitive action, and opens the valve hole 13 when the temperature decreases. Thereby, the condensate is discharged to the outlet 2 from the opening 10 having a narrow passage area and the opened valve hole 13. As described above, when the temperature is low, the condensate is discharged from the opening 10 having a large passage area, so that a large amount of low-temperature condensate can be discharged quickly.

[0013]

As described above, according to the present invention, when the fluid temperature on the inlet side is low, the valve seat increases the passage area of the opening by the first thermal response element which responds to the fluid temperature on the inlet side. Therefore, an excellent effect that a large amount of low-temperature condensate can be quickly discharged from an opening having a large passage area is obtained.

[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 Inlet 2 Outlet 3 Main body 4 Lid 5 Lid 6 Valve room 7 Valve seat accommodating room 8 Inlet passage 9 Communication passage 10 Opening 12 Outflow passage 13 Valve hole 15 Valve seat 16 Inlet chamber 17 1st thermal response element 19 2nd thermal response element

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] April 12, 2000 (2004.1.
2)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG.

Claims (1)

[Claims] A valve seat is formed in a casing having an inlet and an outlet, an opening having a large passage area communicating the valve chamber and the outlet is provided, and a valve seat having a valve hole communicating the valve chamber and the outlet is opened. The first heat-responsive element is connected to the valve seat so as to increase the passage area of the opening at a low temperature and reduce the temperature at a high temperature in response to the fluid temperature on the inlet side and open and close the valve hole in response to the fluid temperature on the inlet side. A heat-responsive steam trap, wherein the second heat-responsive element is disposed in the valve chamber.