JP4115821B2 - Thermally responsive steam trap - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a steam trap that automatically discharges condensate generated in various steam-using devices and steam pipes, and in particular, by using a temperature control element including a medium that is heated, expanded, cooled, and contracted. The present invention relates to a thermally responsive steam trap that discharges a fluid having a temperature below the system.
[0002]
[Prior art]
[Patent Document 1]
Japanese Patent No. 3355388 A thermally responsive steam trap using a temperature control element is disclosed in, for example, Japanese Patent No. 3355388. As understood from the publication, the valve casing forms an inlet, a valve chamber, and an outlet, a valve seat member having a lead-out path is disposed between the valve chamber and the outlet, two upper and lower wall members, and both walls A temperature control element comprising a diaphragm member having an outer peripheral edge fixed between the 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 lead-out path. The expansion medium is formed from a mixture of an alcohol such as propanol having a boiling point lower than that of water and 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 outlet passage to prevent the steam from being discharged. When a low-temperature fluid having a predetermined temperature or less flows in, the expansion medium contracts and the diaphragm member is displaced in the valve opening direction by the fluid pressure on the inlet side. As a result, the valve member opens the outlet passage and discharges condensate and air out of the system.
[0004]
[Problems to be solved by the invention]
In the above prior art, if the diaphragm member is damaged, the expansion medium leaks from the temperature control element. Therefore, when used in fields such as food and medical care, there is a problem that leads to a serious accident. Therefore, the technical problem of the present invention is 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 damaged.
[0005]
[Means for Solving the Problems]
The technical means of the present invention taken in order to solve the above technical problem is that a valve casing forms an inlet, a valve chamber, and an outlet, and a valve seat member having a lead-out path is disposed between the valve chamber and the outlet. And an upper and lower wall members, a diaphragm member having an outer peripheral edge fixed between both wall members, an expansion medium sealed between the upper wall member and the diaphragm member, and a valve member connected to the diaphragm member. The temperature control element is arranged in the valve chamber, and the outlet member is opened and closed by driving the valve member by the displacement of the diaphragm member due to expansion and contraction of the expansion medium. The outer peripheral wall is the inner peripheral wall of the lower wall member, and the inner wall wall is the valve. The heat-responsive steam trap is characterized in that a piston member that airtightly slides on the outer peripheral wall of the member is provided to form a sealed space between the diaphragm member and the piston member.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
The thermally responsive steam trap of the present invention is provided with a piston member in which the outer peripheral wall slides airtightly on the inner peripheral wall of the lower wall member, and the inner wall wall seals between the diaphragm member and the piston member. A space is formed. Therefore, when the diaphragm member is damaged, the expansion medium does not flow into the sealed 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 same axis on the main body 1, 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 in which a lead-out passage 6 for communicating the valve chamber 4 and the outlet 3 is formed is screwed to the opening end of the outlet 3 on the valve chamber 4 side.
[0008]
A temperature control element 8 is disposed 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 that seals the inlet 9, a diaphragm member 13 that seals an expansion medium 14 between the upper wall member 10, and a diaphragm member 13, a valve member 15 that is fixedly attached to the valve seat member 7 and opens and closes the outlet path 6, a lower wall member 16 that is fixed with the outer peripheral edge of the diaphragm member 13 sandwiched between the upper wall member 10, and an outer periphery The wall is formed by a piston member 17 that airtightly slides on the inner peripheral wall of the lower wall member 16 and the inner wall wall on the outer peripheral wall of the valve member 15, 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 an alcohol such as propanol having a boiling point lower than that of water and water.
[0009]
The temperature control element 8 is accommodated in a bottomed cylindrical mounting member 18 fixed between the main body 1 and the valve seat member 7, one end is fixed to the lid member 5, and the other end is a temperature controller. 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, is fixed by fitting one end into 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. The other end is fixed by fitting into the plug member 11. The attachment 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 starting, the temperature in the valve chamber 4 is low, 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 is separated from the valve seat member 7. The lead-out path 6 is opened. As a result, low-temperature condensate or air flowing in from the inlet 2 is discharged from the outlet path 6 to the outlet 3. When the temperature of the fluid flowing in from the inlet 2 rises due to the discharge of the low-temperature fluid and the inside of the valve chamber 4 reaches 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, the valve member 15 is seated on the valve seat member 7 and the outlet path 6 is closed. This prevents steam leakage. When the inside of the valve chamber 4 falls below 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 is separated from the valve seat member 7. Thus, the outlet path 6 is opened.
[0011]
When the diaphragm member 13 is damaged, the expansion medium 14 does not flow into the sealed space 12 and leak from the temperature control element 8.
[0012]
【The invention's effect】
As described above, the present invention provides a piston member in which the outer peripheral wall slides airtightly on the inner peripheral wall of the lower wall member and the inner wall wall airtightly slides on the outer peripheral wall of the valve member, thereby providing a sealed space between the diaphragm member and the piston member. By forming, an excellent effect is obtained that the expansion medium does not leak from the temperature control element even if the diaphragm member is damaged.
[Brief description of the drawings]
FIG. 1 is a cross-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 chamber 5 Lid member 6 Outlet path 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 Attachment member

Claims (1)

The valve casing forms an inlet, a valve chamber, and an outlet. A valve seat member having a lead-out path is disposed between the valve chamber and the outlet, and the outer peripheral edge is fixed between the upper and lower wall members and the both wall members. A temperature control element comprising 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 formed by expansion and contraction of the expansion medium. A valve member is driven by displacement to open and close the lead-out path. A diaphragm member and a piston are provided by providing a piston member in which the outer peripheral wall slides airtightly on the inner peripheral wall of the lower wall member and the inner wall wall airtightly slides on the outer peripheral wall of the valve member. A thermally responsive steam trap, characterized in that a sealed space is formed between the members.

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