JP2004190823A - Thermally-actuated steam trap - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermally actuated steam trap capable of preventing a leak of the expansion medium from a temperature control mechanical element even if a diaphragm member is broken. <P>SOLUTION: A cover member 5 is fitted to a main body 1 formed with an inlet 2 and an outlet 3 to form a valve chamber 4 having the inlet 2 and the outlet 3 to be opened inward. A valve seat member 7 formed with a lead-out passage 6 for communicating the valve chamber 4 with the outlet 3 is joined by screws. The temperature control mechanical element 8 is formed of an upper wall member 10, the diaphragm member 13 for sealing the expansion medium 14 between the upper wall member 10, a valve member 15 fixed to the diaphragm member 13 to open/close a valve hole 16 by separating/seating from/on the valve seat member 7, a lower wall member 16 for pinching the peripheral edge of the diaphragm member 13 for fixation between the upper wall member 10, a piston member 17, of which outer peripheral wall air-tightly slides on the inner peripheral wall of the lower wall member 16 and of which inner peripheral wall air-tightly slides on the outer peripheral wall of the valve member 15, and a seal space 12 formed between the diaphragm member 13 and the piston member 17. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a steam trap for automatically discharging condensate generated in various steam-using devices and steam pipes, and more particularly, to a steam trap using a temperature control element including a medium that is heated, expanded, cooled, and contracted. The present invention relates to a heat-responsive steam trap that discharges a fluid having a temperature lower than the outside of the system.
[0002]
[Prior art]
[Patent Document 1]
Japanese Patent No. 3355388 discloses a thermally responsive steam trap using a temperature control element. As understood from the publication, an inlet, a valve chamber, and an outlet are formed in a valve casing, a valve seat member having an outlet path is disposed between the valve chamber and the outlet, and two upper and lower wall members, A temperature control element comprising a diaphragm member having an outer peripheral edge fixed between members, an expansion medium sealed between the upper wall member and the diaphragm member, and a valve member connected to the diaphragm member is disposed in the valve chamber. The valve member is driven by the displacement of the diaphragm member due to the expansion and contraction of the expansion medium to open and close the outlet path. The expansion medium is formed of a mixture of water and an alcohol, such as propanol, which has a lower boiling point than water.
[0003]
When a high-temperature fluid having a predetermined temperature or more flows into the valve chamber, the expansion medium expands and displaces the diaphragm member toward the valve seat member against the fluid pressure on the inlet side. As a result, the valve member closes the lead-out path and prevents discharge of steam. When a low-temperature fluid having a predetermined temperature or less flows, the expansion medium contracts and displaces the diaphragm member in the valve opening direction by the fluid pressure on the inlet side. As a result, the valve member opens the lead-out path and discharges condensate and air out of the system.
[0004]
[Problems to be solved by the invention]
In the above-mentioned prior art, when the diaphragm member is damaged, the expansion medium leaks from the temperature control element. Therefore, when used in the fields of food and medicine, there is a problem that leads to a serious accident. Accordingly, it is an object of the present invention to provide a thermally responsive steam trap in which the expansion medium does not leak from the temperature control element even if the diaphragm member is broken.
[0005]
[Means for Solving the Problems]
The technical means of the present invention taken to solve the above technical problem is that an inlet, a valve chamber, and an outlet are formed in a valve casing, and a valve seat member having an outlet path is disposed between the valve chamber and the outlet. The upper and lower wall members, a diaphragm member having an outer peripheral edge fixed between the two wall members, an expansion medium sealed between the upper wall member and the diaphragm member, and a valve member connected to the diaphragm member. A temperature control element is arranged in a valve chamber, and a valve member is driven by displacement of a diaphragm member due to expansion and contraction of an expansion medium to open and close a lead-out path, wherein an outer peripheral wall is an inner wall of a lower wall member and an inner wall is a valve. A thermally responsive steam trap is characterized in that a closed space is formed between the diaphragm member and the piston member by providing a piston member that hermetically slides the outer peripheral wall of the member.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
The thermally responsive steam trap of the present invention is provided with a piston member whose outer peripheral wall slides on the inner peripheral wall of the lower wall member in an airtight manner on the outer peripheral wall of the valve member, and hermetically seals between the diaphragm member and the piston member. It forms a space. Therefore, when the diaphragm member is damaged, the expansion medium does not flow into the closed space and leak from the temperature control element.
[0007]
【Example】
An embodiment showing a specific example of the above technical means will be described (see FIG. 1). An inlet 2 and an outlet 3 are formed on the main body 1 on the same axis, and a valve chamber 4 communicating with the inlet 2 and the outlet 3 is formed by a lid member 5 screwed to the main body 1. A valve seat member 7 having a lead-out passage 6 communicating the valve chamber 4 and the outlet 3 is screw-connected to an opening end of the outlet 3 on the valve chamber 4 side.
[0008]
A temperature control element 8 is arranged above the valve seat member 7. The temperature control element 8 includes an upper wall member 10 having an inlet 9, a plug member 11 for sealing the inlet 9, a diaphragm member 13 for sealing an expansion medium 14 between the upper wall member 10, and a diaphragm member. A valve member 15 fixed to and attached to the valve seat member 7 and detachably seated on the valve seat member 7 to open and close the outlet passage 6; a lower wall member 16 fixed to the outer peripheral edge of the diaphragm member 13 with the upper wall member 10 interposed therebetween; The wall is formed of a piston member 17 whose inner wall wall slides on the outer peripheral wall of the valve member 15 in an airtight manner on the inner peripheral wall of the lower wall member 16, and a sealed space 12 between the diaphragm member 13 and the piston member 17. The expansion medium 14 is formed of a mixture of alcohol and water, such as propanol, which has a lower boiling point than water.
[0009]
The temperature control element 8 is housed in a bottomed cylindrical mounting member 18 fixed between the main body 1 and the valve seat member 7, and has one end fixed to the lid member 5 and the other end connected to the temperature control device. The lower surface of the lower wall member 16 is held in contact with the step portion 20 of the mounting member 18 by the urging force of the coil spring 19 fixed to the element 8. The coil spring 18 is formed such that the coil diameter at one end is larger than the inner diameter of the lid member 5 and is fixed by fitting one end to the inner wall of the lid member 5, and the coil diameter at the other end is smaller than the diameter of the plug member 11. Then, the other end is fixed by being fitted into the plug member 11. The mounting member 18 has a fluid passage hole 21 in the bottom wall and three fluid passage windows 22 in the peripheral wall.
[0010]
The operation in this embodiment is as follows.
At the time of startup, the temperature in the valve chamber 4 is low, the expansion medium 14 contracts, the fluid pressure on the inlet side displaces the piston member 17 and the diaphragm member 13 upward, and the valve member 15 separates from the valve seat member 7. The outlet path 6 is opened. As a result, low-temperature condensate and air flowing in from the inlet 2 are discharged from the outlet 6 to the outlet 3. When the temperature of the fluid flowing from the inlet 2 rises due to the discharge of the low-temperature fluid, and the inside of the valve chamber 4 becomes a predetermined temperature or more, the expansion medium 14 expands, and the piston member 17 and the diaphragm member 13 resist the fluid pressure on the inlet side. Is displaced downward, and the valve member 15 is seated on the valve seat member 7 to close the outlet passage 6. This prevents leakage of steam. When the temperature inside the valve chamber 4 becomes lower than a predetermined temperature due to heat radiation, the expansion medium 14 contracts, the piston member 17 and the diaphragm member 13 are displaced upward by the fluid pressure on the inlet side, and the valve member 15 separates from the valve seat member 7. Then, the outlet path 6 is opened.
[0011]
When the diaphragm member 13 is broken, the expansion medium 14 does not flow into the closed space 12 and leak from the temperature control element 8.
[0012]
【The invention's effect】
As described above, the present invention provides a closed space between the diaphragm member and the piston member by providing a piston member having an outer peripheral wall sliding on the inner peripheral wall of the lower wall member on the inner peripheral wall of the valve member in an airtight manner. By forming, the excellent effect that the expansion medium does not leak from the temperature control element even if the diaphragm member is broken 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 Main body 2 Inlet 3 Outlet 4 Valve room 5 Lid member 6 Outlet 7 Valve seat member 8 Temperature control element 10 Upper wall member 13 Diaphragm member 14 Expansion medium 15 Valve member 16 Lower wall member 17 Piston member 18 Mounting member

Claims (1)

An inlet, a valve chamber, and an outlet are formed in the valve casing, a valve seat member having an outlet passage is disposed between the valve chamber and the outlet, and the outer peripheral edge is fixed between the upper and lower two wall members and both wall members. A temperature control element including a diaphragm member, an expansion medium sealed between the upper wall member and the diaphragm member, and a valve member connected to the diaphragm member is disposed in the valve chamber, and the diaphragm member is expanded and contracted by expansion and contraction of the expansion medium. A piston member, in which an outer peripheral wall slides on an inner peripheral wall of a lower wall member in an airtight manner on an outer peripheral wall of a valve member, wherein a diaphragm member and a piston are provided. A thermally responsive steam trap, wherein a closed space is formed between the steam trap and the member.

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