JPH0828787A - Thermally-actuated steam trap - Google Patents

Abstract

PURPOSE:To reduce the manufacturing cost of a thermally-actuated steam trap by using a temperature control machine element including medium to be expanded/shrunk according to temperature, providing a check valve opening between an inlet and a valve chamber, and integrating the check valve mechanism to open/close the check valve opening by a check valve part in a wall member, into the thermally-actuated stem trap. CONSTITUTION:When fluid temperature in a valve body 3 is low, an expansion medium 16 is in a shrunk condition, thus a diaphragm 15 is displaced on a wall member 12 side, and a valve member 17 is separated from a valve seat member 8 so as to fully open a lead-through passage 7. When the fluid temperature in a valve chamber 3 is raised by discharging low temperature fluid so that the expansion medium 16 is expanded, the diaphragm 15 is displaced on a fixed wall member 18 side, and the valve member 17 is seated on the valve seat member 8 so as to close the lead-through passage 7. When fluid pressure on an outlet side 5 is raised higher than an inlet 4 side during the foregoing process, a temperature control machine element 10 is displaced on a check valve opening 9 side against springs 19 by receiving the action of the fluid pressure on the outlet 5 side so that the wall member 12 closes the check valve opening 9 and fluid backflow is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field 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, it is heated and cooled by steam and condensate and expands according to its temperature. The present invention relates to a heat-actuated steam trap that discharges condensed water below a desired temperature to the outside of a system by using a temperature control element containing a contracting medium.

[0002]

2. Description of the Related Art The basic structure of a heat-actuated steam trap is known, for example, from Japanese Patent Publication No. 60-46318. As understood from the publication, the outer peripheral edge of the diaphragm is fixed between the upper and lower dish-shaped wall members, the expansion medium is enclosed in the internal space between the upper wall member and the diaphragm, and the valve member is connected to the diaphragm. The temperature control element is placed in the valve chamber that communicates with the inlet, and the expansion / contraction of the expansion medium is used to drive the valve member through the diaphragm, and thereby the discharge path that communicates the valve chamber with the outlet. The valve seat member having the above-mentioned structure allows the valve member to be seated on and off.

When a high temperature fluid having a temperature higher than a predetermined temperature flows into the valve chamber, the expansion medium expands to displace the diaphragm in the valve closing direction so that the valve member is seated on the valve seat member and the outlet passage is closed. This prevents the discharge of steam. When a low-temperature fluid below a predetermined temperature flows in, the expansion medium contracts, the fluid pressure in the valve chamber causes the diaphragm to be displaced in the valve opening direction, the valve member separates from the valve seat member, and the lead-out path is opened. . As a result, condensed water and air are discharged outside the system.

[0004]

However, in the heat-actuated steam trap of this type, when the fluid pressure on the outlet side becomes higher than that on the inlet side, the fluid on the outlet side flows backward and various vapors are generated. There was a problem of reaching the equipment used and reducing the thermal efficiency of the equipment using steam. In addition, when a shocking backflow occurs due to a water hammer at the outlet side, there is a problem that steam-using equipment is damaged.

Therefore, a technical problem of the present invention is to provide a heat-actuated steam trap having a backflow preventing function.

[0006]

Means for Solving the Problems The technical means of the present invention taken to solve the above-mentioned technical problems include a valve casing having an inlet, a valve chamber, and an outlet, and a space between the valve chamber and the outlet. The expansion passage is provided in the inner wall of the diaphragm and the outer peripheral edge of the diaphragm is fixed to the inner space for enclosing the expansion medium, and the diaphragm is provided with a temperature control element having a valve portion. In this way, the temperature control element is placed in the valve chamber, and in the thermally actuated steam wrap in which the valve portion opens and closes the outlet passage by the displacement of the diaphragm based on the expansion and contraction of the expansion medium, there is a outlet passage between the inlet and the valve chamber A check valve opening is provided in the coaxial direction, a spring for urging the temperature control element toward the outlet path is provided, and a check valve portion for opening and closing the check valve opening is provided on the wall member. is there.

[0007]

The operation of the above technical means is as follows.
When a high temperature fluid having a temperature equal to or higher than a predetermined temperature flows into the valve chamber from the inlet, the expansion medium expands, the diaphragm is displaced in the valve closing direction, and the valve portion closes the outlet passage. This prevents the discharge of steam. When a low-temperature fluid below a predetermined temperature flows in, the expansion medium contracts, the diaphragm is displaced in the valve opening direction, and the valve portion opens the discharge passage. As a result, condensed water and air are discharged outside the system.

When the fluid pressure on the outlet side becomes higher than that on the inlet side, the temperature control element is acted on by the fluid pressure on the outlet side to resist the spring and is displaced to the check valve mouth side, and the check valve portion is opened. Close the check valve port. This prevents backflow from the outlet side to the inlet side. Then, when the fluid pressure on the outlet side decreases and becomes lower than that on the inlet side, the temperature control element is displaced by the fluid pressure on the inlet side and the action of the spring, is displaced to the outlet path side, and the diaphragm of the diaphragm based on expansion and contraction of the expansion medium is The displacement causes the valve portion to open and close the outlet path.

[0009]

EXAMPLE An example showing a concrete example of the above technical means will be described (see FIG. 1). Upper casing 1 and lower casing 2
And are screwed together to form a valve casing having the valve chamber 3 therein. An inlet 4 is formed in the upper casing 1 and an outlet 5 is formed in the lower casing 2. The inlet 4 and the outlet 5 are formed coaxially. A valve seat member 8 having a lead-out passage 7 that connects the valve chamber 3 and the outlet 5 is screwed to the transverse wall 6 of the lower casing 2. A check valve port 9 is formed in the upper casing 1 to connect the inlet 4 and the valve chamber 3. The outlet path 7 and the check valve opening 9 are formed coaxially.

A temperature control element 10 is located above the valve seat member 8. The temperature control element 10 includes a wall member 12 having an inlet 11, a plug member 13 sealing the inlet 11, and a wall member 1.
A diaphragm 15 that forms a storage chamber 14 between the diaphragm 15 and
The expansion medium 16 sealed in the accommodation chamber 14 and the diaphragm 1
The valve member 17 fixed to the valve member 5 and the fixed wall member 18 fixed to the wall member 12 with the outer peripheral edge of the diaphragm 15 sandwiched therebetween. The valve member 17 is seated on and off the valve seat member 8 to form a valve portion that opens and closes the lead-out path 7. The upper surface of the wall member 12 forms a check valve portion that opens and closes the check valve opening 9. The expansion medium 16 is formed of water, a liquid having a boiling point lower than that of water, or a mixture thereof.

The temperature control element 10 includes a wall member 12 and an upper case.
A step of a plurality of ribs 20 is energized toward the lead-out path 7 by a coil-shaped spring 19 arranged between the sings 1, and the outer periphery of the lower surface of the fixed wall member 18 is formed on the inner periphery of the lower casing 2. Held against the department. The outer periphery of the temperature control element 10 is guided in the vertical direction by the rib 20.

When the temperature of the fluid flowing into the valve chamber 3 from the inlet 4 is low, the expansion medium 16 contracts, the diaphragm 15 is displaced toward the wall member 12 side, and the valve member 17 is closed, as shown in FIG. Separates from the valve seat member 8 and opens the lead-out path 7. When the temperature of the fluid flowing from the inlet 4 into the valve chamber 3 becomes high due to the discharge of the low temperature fluid, the expansion medium 16
Expands, the diaphragm 15 is displaced toward the fixed wall member 18, and the valve member 17 is seated on the valve seat member 8 to close the lead-out passage 7. When the temperature inside the valve chamber 3 decreases due to heat dissipation or the temperature of the fluid flowing from the inlet 4 into the valve chamber 3 decreases, the expansion medium 16 contracts and the diaphragm 15 is displaced toward the wall member 12 side. The valve member 17 is separated from the valve seat member 6 to open the lead-out passage 7, and the state shown in FIG. 1 is obtained.

When the fluid pressure on the outlet 5 side becomes higher than that on the inlet 4 side, the temperature control element 10 is displaced toward the check valve port 9 side against the spring 19 under the action of the fluid pressure on the outlet 5 side. The wall member 12 closes the check valve opening 9. This makes exit 5
Side to inlet 4 side backflow is prevented. Then, when the fluid pressure on the outlet 5 side decreases and becomes lower than that on the inlet 4 side, the temperature control element 10 is displaced by the fluid pressure on the inlet 4 side and the spring 19 and is displaced to the lead-out path 7 side to form the rib. The valve member 17 is held against the stepped portion 20 and the valve member 17 is seated on and off the valve seat member 8 by the displacement of the diaphragm 15 based on the expansion and contraction of the expansion medium 16 to open and close the lead-out path 7.

[0014]

The present invention produces the following unique effects. If a separate check valve is connected to the outlet side of the heat-actuated steam trap, the cost of the check valve is high and piping work is required. According to the present invention, since the check valve function is built in the heat-actuated steam trap, the cost is low and the labor of separately installing a check valve can be saved.

[Brief description of drawings]

FIG. 1 is a sectional view of a heat-actuated steam trap according to an embodiment of the present invention.

[Explanation of symbols]

 1 Upper case 2 Lower case 3 Valve chamber 4 Inlet 5 Outlet 7 Outlet path 9 Check valve port 10 Temperature control element 12 Wall member (check valve part) 15 Diaphragm 16 Expansion medium 17 Valve member (valve part) ) 19 springs

Claims (1)

[Claims] 1. A valve casing having an inlet, a valve chamber and an outlet, an outlet passage provided between the valve chamber and the outlet, and an inner space formed by fixing a wall member and an outer peripheral edge of a diaphragm. It is equipped with a temperature control element that encloses the medium and has a valve part on the diaphragm.The temperature control element is placed in the valve chamber with the diaphragm facing the outlet path, and the diaphragm is displaced by the expansion and contraction of the expansion medium. In the case where the valve portion opens and closes the outlet passage, a check valve opening coaxial with the outlet passage is provided between the inlet and the valve chamber, a spring for urging the temperature control element toward the outlet passage is provided, and the wall member is provided. A heat-actuated steam trap, which is provided with a check valve portion for opening and closing the check valve opening.