JP2731000B2 - steam trap - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a steam trap operated by a working medium enclosed in a sealed chamber defined in a capsule by a diaphragm.

[Conventional technology]

FIG. 4 shows an example of the configuration of a conventional steam trap of this type. In the figure, reference numeral 21 denotes a valve box having an inlet 21a and an outlet 21b, 22 denotes a lid attached to the valve box 21, 23 denotes a gasket, and 24 denotes a gasket. Is a trap chamber, 25 is a capsule configured to open and close a valve seat opening described later, 26 is a valve seat body screwed to the valve box 21 and formed with a valve seat opening 26a, 27, 27 ' Is a capsule that is welded along the periphery with a diaphragm described later
25 shells. The capsule 25 is moved to the trap chamber 24 by the engagement of the claws 27'a of the shell 27 'with the engagement grooves 26b of the valve seat 26.
It is fixed inside. 28 is a corrugated diaphragm sandwiched and fixed between the peripheral portions of the shells 27 and 27 ', 29 is a valve body fixed to the center of the diaphragm 28, 30
Is a sealed chamber defined by a shell 27 and a diaphragm 28, in which a working medium composed of a volatile chemical is sealed, and 31 is a reinforcing plate welded to the valve body 29 together with the diaphragm 28. .

In such a steam trap, the inlet 21a of the valve box 21
When the condensate flowing in from the reservoir 25 accumulates around the capsule 25, the temperature of the sealed chamber 30 decreases and the vapor pressure of the working medium decreases, and as a result, the diaphragm 28 is pressed toward the shell 27 side by the pressure of the condensate, The valve body 29 is separated from the valve seat body 26 to open the valve seat opening 26a, and the condensate is discharged from the outlet 21b through the valve seat opening 26a. Also, if high-temperature condensate or steam flows into the trap chamber 24, the working medium whose vapor pressure has increased expands, contrary to the above case, and presses the diaphragm 28 toward the shell 27 ', and as a result, The valve body 29 is in close contact with the valve seat body 26 and closes the valve seat opening 26a, thereby preventing leakage of water vapor from the trap chamber 24.

On the other hand, FIG. 5 shows another configuration example of a conventional steam trap. In this apparatus, an upper diaphragm 34 having a reinforcing plate 32 and a spherical valve body 33 fixed at a central portion, and a shell body
The lower diaphragm 35, the inner peripheral edge of which is welded along the opening 27 ', is welded to each other at the outer peripheral edge, and the entire capsule 25 is made up of a valve seat body by a holder 36 having a large number of holes 36a. Supported on 26. And sealed room 30
Is the upper diaphragm 34 and the lower diaphragm 35 and the shell 27,2
7 ', in which the same working medium as in the example shown in FIG. 4 is enclosed.

In the steam trap of the configuration example shown in FIG. 5, when the vapor pressure of the working medium is reduced, the pressure of the condensate flowing between the upper and lower diaphragms 34 and 35 through the hole 36a of the holder 36 causes the upper diaphragm 34 to move. When the spherical valve element 33 fixed to the opening of the valve seat 26a and the vapor pressure of the working medium rises,
The upper and lower diaphragms 34, 35 are crushed so as to be in close contact with each other, and the spherical valve body 33 closes the valve seat opening 26a, and thus the sealed chamber 30 by the condensate or steam in the trap chamber 24. The valve seat 26
It opens and closes a.

[Problems to be solved by the invention]

However, in a device using this type of steam trap, high-temperature steam and low-temperature condensate may be mixed, and at that time, a kind of pressure impact called a so-called steam hammer occurs, and the diaphragm acts due to this impact. There was a problem of damage. For example, in the case of the example shown in FIG. 4, the portion of the diaphragm 28 shown in particular, when intense pressure caused by steam hammer is transmitted to the surroundings of the capsule 25 code P ₁ is longer shell 27 and the reinforcing plate
At 31 it can't be sustained and will be damaged due to excessive stress on it. On the other hand, in the case of the example shown in Fig. 5, for pressure impulse steam hammer to expand press between upper and lower diaphragms 34 and 35, easily vicinity of their welded joints P ₂ is made to explode, further, portion indicated by symbol P ₃ also was easy to reach the breakage not completely support the shell 27 and the reinforcing plate 32.

Further, when the steam trap device is in a high temperature state, if the lid 22 is removed for disassembly, inspection, etc., the pressure in the trap chamber 24 drops rapidly, but in this case, the vapor pressure of the working medium is high. Since the pressure is maintained as it is, the pressure difference between the inside and the outside of the sealed chamber 30 is significantly increased, and in particular, the diaphragm 28 and the upper diaphragm 34 indicated by the reference numeral P4 in FIGS. ₄ and 5 are damaged.

In view of such circumstances, an object of the present invention is to provide a steam trap that prevents damage to a diaphragm even when a pressure impact or the like occurs due to a steam hammer, and that can always guarantee safe operation.

[Means for solving the problem]

The steam trap device according to the present invention stretches a pair of upper and lower diaphragms fixed along their peripheral portions between shells having an opening in the center, and forms a sealed chamber defined by the upper and lower diaphragms. It has a disk-shaped capsule in which the working medium is sealed, and a valve seat fixed to the lower diaphragm is provided with a valve seat fixed on the lower side of the capsule, which is supported via a diaphragm holder fixed to the upper diaphragm. Although it opens and closes, an annular reinforcing plate is attached along the outer periphery of the diaphragm holder and the valve body.

Further, a capsule holder capable of elastically supporting the diaphragm holder directly or via a capsule cover is provided.

(Operation)

According to the present invention, when the working medium in the sealed chamber expands, the upper and lower diaphragms are supported by the capsule shell and the reinforcing plate in contact with each other, whereby the upper and lower diaphragms are almost evenly supported as a whole, and are locally localized. No excessive stress is applied to the substrate.

Also, due to the elasticity of the capsule holder, the capsule can move against the elasticity of the capsule holder until the upper and lower diaphragms come into contact with the shell due to the expansion of the working medium, thereby reducing the impact on the upper and lower diaphragms. it can.

〔Example〕

Hereinafter, a first embodiment of the steam trap device according to the present invention will be described with reference to FIG. First, in the figure, the entrance
A lid 2 is mounted via a gasket 3 on a valve box 1 having an outlet 1a and an outlet 1b so that a capsule 5 opens and closes a valve seat opening 6a of a valve seat body 6. FIG. The right and left halves indicate the closed state and the open state of the valve seat opening 6a. And further in the figure, 7,7 'opening 7a in the central portion of each, 7a' shell of the capsule 5 which allowed to fixation is being formed a vertical diaphragm, which will be described later along their periphery by welding W _1, 8, Reference numeral 9 denotes a wavy upper diaphragm and a lower diaphragm stretched between the shells 7 and 7 ', and reference numeral 10 denotes a welding W along an outer peripheral portion of the opening 7a of the shell 7 so as to be disposed substantially at the center of the opening 7a. diaphragm holder for fixing onto the diaphragm 8 by _2, the valve body to stick to the lower diaphragm 9 by welding W ₃ along its outer periphery as 11 is disposed on the upper side of the aligned and the valve seat opening 6a in the diaphragm holder 10 ,
12, 12 'is to the diaphragm holder 10 together with the upper diaphragm 8 by welding W _2, and welding W ₃ to the valve body 11 with the bottom diaphragm 9 by the respective fixed, the opening 7a and the clearance and opening 7a between diaphragm holder 10' and the valve An annular reinforcing plate 13 is fixed to the diaphragm holder 10 so as to close the gap between the bodies 11, and is elastically deformable to hold the capsule 5 by engaging with the engaging hole 2a formed in the lid 2 and at the same time. Capsule holder. And upper and lower diaphragm
A sealed chamber 14 is defined between 8, 9 in which the working medium is enclosed.

Since the steam trap according to the present invention is configured as described above, the working medium in the sealed chamber 14 expands and contracts due to the temperature change caused by the condensed water or the steam in the trap chamber 4, and the valve seat 11 is formed by the valve body 11. The opening and closing of the port 6a is performed. If the above-mentioned steam hammer occurs during the operation, the pressure impact acts on the upper and lower diaphragms 8 and 9 so that they are crushed as shown in FIG. It is. In this case, the upper and lower diaphragms 8, 9 are in close contact with each other, so that no excessive stress is applied to the upper and lower diaphragms 8, 9 and there is no risk of breakage.

On the other hand, when the vapor pressure of the working medium in the sealed chamber 14 is high, when a blow valve (not shown) on the inlet 1a side is rapidly opened to condense water or release steam, the working medium expands and the upper and lower diaphragms 8 expand. , 9 are separated from each other (valve-closed state), but are equally supported by the inner surfaces of the shells 7, 7 ', so that no excessive stress is generated. In this case, especially when the pressure difference between the inside and outside of the sealed chamber 14 is large, the diaphragm holder 10 moves upward against the elasticity of the capsule holder 13, whereby the reinforcing plates 12, 12 ′ move the shells 7, 7 ′. The diaphragms 8, 9 are pressed against the shells 7, 7 'in such a state, so that the diaphragms 8, 9 are pressed against the shells 7, 7'. No excessive force acts on the diaphragms 8,9.

By providing the reinforcing plates 12 and 12 'in this manner, excessive stress is not locally generated in the diaphragms 8 and 9, so that not only can the breakage be prevented, but also the service life is prolonged and the safety operation during the operation is improved. Is guaranteed. by the way,
In the opening / closing operation of the valve seat 6a by the valve body 11, the vertical movement amount of the valve body 11 is equally shared by the movement amounts of the upper and lower diaphragms 8, 9, so that the movement amounts of the upper diaphragm 8 and the lower diaphragm 9 are conventionally Since only half of the case of the steam trap device shown in the example (see FIG. 4) is required, and the stress generated according to the operation amount is small, the life of the diaphragms 8 and 9 is also prolonged in this respect.

FIG. 2 shows a second embodiment of the steam trap according to the present invention. In this example, at least three resiliently deformable capsule holders 16 and a strain net 17 are caulked around the outer periphery of the capsule cover 15 fixed to the diaphragm holder 10, and one end of each capsule holder 16 is attached to the lid 2. The whole capsule 5 is held in the trap chamber 4 by being held by the formed step portion 2b and fitting the convex portion 17a of the strain net 17 into the concave portion 6b formed in the valve seat body 6.

Also in the case of the second embodiment, when the upper and lower diaphragms 8, 9 are operated by expansion and contraction of the working medium in the sealed chamber 14, the upper and lower diaphragms 8, 12 'are supported by the reinforcing plates 12, 12' so that the upper and lower diaphragms 8, 12 'are supported. The occurrence of excessive stress is prevented as in the case of the first embodiment. In particular, when the working medium expands rapidly, the capsule holder 16 is appropriately elastically deformed by the capsule cover 15 pushed up by the diaphragm holder 10, whereby the upper and lower diaphragms 8, 9 are shell bodies 7, 7. ′ Until the capsule 5 comes into close contact, and the upper and lower diaphragms 8 and 9 are uniformly and entirely supported. The capsule holder 16 may be supported by a guide projection 2c formed on the lid 2 as shown in FIG. 3, and may be a coil spring 16 'configured to press the capsule cover 15 with an appropriate force. An elastic member such as a leaf spring may be used instead of the coil spring 16 '.

The upper and lower diaphragms 8 and 9 in each of the above embodiments may be flat in addition to the wavy shape, or each of the upper and lower diaphragms 8 and 9 may be configured by two or more thin diaphragms. . Furthermore, capsule holder
13 and 16 may be held not by the lid 2 but by a support member provided on the valve box 1 side.

〔The invention's effect〕

As described above, the steam trap of the present invention has excellent durability against a steam hammer and an abnormally high pressure difference.
Since the stress generated in the diaphragm during normal operation can be reduced, it is possible to use a thin diaphragm,
As a result, not only the operation sensitivity of the trap is improved, but also there are advantages such as ensuring accurate and smooth operation and long life.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a first embodiment of a steam trap according to the present invention, FIG. 2 is a longitudinal sectional view of a second embodiment of the steam trap according to the present invention, and FIG. 3 is a modification of the second embodiment. FIGS. 4 and 5 are longitudinal sectional views showing a configuration example of a conventional steam trap. 1 ... valve box, 2 ... lid, 5 ... capsule, 6 ... valve seat, 7, 7 '... shell, 8 ... upper diaphragm, 9 ... lower diaphragm, 10 ... diaphragm holder, 11… Valve, 12,12 ′… Reinforcing plate, 13,16 …… Capsule holder,
14 ... sealed room, 15 ... capsule cover.

Claims (2)

(57) [Claims] 1. A pair of upper and lower diaphragms fixed along a peripheral edge of a shell having an opening at a central portion are stretched, and a working medium is sealed in a sealed chamber defined by the upper and lower diaphragms. A disc-shaped capsule is provided, and a valve seat disposed below the capsule, which is supported via a diaphragm holder fixed to the upper diaphragm, is opened and closed by a valve disc fixed to the lower diaphragm. An annular reinforcing plate is attached along the outer periphery of the diaphragm holder and the valve body, so that when the working medium expands, the upper and lower diaphragms are contacted and supported by the capsule shell and the reinforcing plate. A steam trap, characterized in that: 2. A capsule holder capable of supporting the diaphragm holder directly or elastically via a capsule cover is provided, and when the working medium expands, the upper and lower diaphragms come into contact with the shell. The steam trap according to claim 1, wherein the capsule is movable against the elasticity of the capsule holder.