JPS6233476B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a disk-type steam trap for discharging condensate generated in a steam system of a steam-using device or the like.

In disc-type steam traps, which is particularly noticeable when used in high-temperature, high-pressure steam systems, leakage occurs even when the valve disc is in a seated state, resulting in contact with the inner ring seating surface and the inner ring seat of the valve disc. There is a problem with circular radial erosion marks in some areas.

This is thought to be due to a thin layer of water interposed between the valve disk and the inner and outer ring seating surfaces. That is,
Immediately after the valve is closed, a thin layer of water forms between the valve disc and the inner and outer ring seating surfaces, and the valve disc is thought to be floating about 0.001 to 0.01mm above the inner and outer ring seating surfaces. There is. However, the pressure difference between the injection hole and the annular groove (with which the discharge hole communicates), which is separated by the inner ring seat, is much greater than the pressure difference between the variable pressure chamber, which is separated by the outer ring seat, and the annular groove (with which the discharge hole communicates). Although the water layer between the valve disk and the outer ring seating surface is maintained, the water layer between the valve disk and the inner ring surface is pushed out, and steam leaks through this small gap.

The present invention aims to solve the above-mentioned problems, and the technical means taken for this purpose is to install a disc-shaped valve disk that sits on and off from a valve seat surface consisting of an inner ring valve seat and an outer ring valve seat, behind the disk-shaped valve disk. In a valve that automatically opens and closes by controlling pressure changes in the variable pressure chamber, an annular narrow groove is formed on the inner valve seat surface, and a small hole communicating between the narrow groove and the variable pressure chamber is formed between the inner and outer rings. It is formed at the lower part of the valve seat surface, and the valve disk does not have a through hole passing through it.

The operation of the above technical means is as follows.

The annular narrow groove provided on the inner ring valve seat passes under the inner and outer ring valve seats and communicates with the variable pressure chamber through a small hole, so steam that attempts to leak from between the valve disk and the inner ring valve seat is absorbed by the narrow groove. The pressure is reduced and a portion of the water becomes condensed.
Therefore, since water is supplied between the valve disk and the inner ring valve seat, a thin layer of water is formed and maintained not only between the valve disk and the outer ring valve seat but also between the inner ring valve seat.
No leakage occurs.

The illustrated embodiment will be described below.

In Fig. 1, 1 is the main body, 2 and 3 are an inlet passage and an outlet passage formed in the main body 1, respectively, 4 is an inner lid screwed onto the upper part of the main body 1, and 5 is an inner lid on the upper part of the main body 1. An outer lid is screwed to cover 4, and 6 is a heat-insulating space between the outer lid 5 and the inner lid 4. 7 is a variable pressure chamber airtightly formed between the main body 1 and the inner cover 4; 8 is an inner ring seat that forms the opening end of the jet hole 9 that opens from the inlet passage 2 to the variable pressure chamber 7; 10 is an inner ring seat. An outer ring seat 11 is formed concentrically with the outer ring seat 8, and an annular groove 11 is formed between the inner and outer ring seats 8 and 10 and communicates with the outlet passage 3 through a discharge hole 12. In addition, the inner and outer ring bearing surfaces 8,
10 is machined to have the same plane with high precision by polishing or the like. Reference numeral 13 denotes a valve disk disposed in a free state within the variable pressure chamber 7, and its lower surface corresponding to the inner and outer ring seats 8 and 10 is finished flat with high precision. and,
An annular space 20 communicating with the variable pressure chamber 7 is formed between the outer periphery of the outer ring seat 10 and the inner cover 4. Annular space 2
0 is deeper than the annular groove 11 and is located at the lowest position of the variable pressure chamber 7.

FIG. 2 is a sectional view taken along the line A-A in FIG. 1, showing the planar shape of the inner and outer ring seats 8 and 10. In the figure, reference numeral 14 denotes a small hole that communicates the thin groove 14 provided in an annular shape on the surface of the inner ring seat 8 with the annular space 20 in the lower part of the variable pressure chamber 7.
In addition, Fig. 3 shows the inner and outer ring seats 8 and 10 in Fig. 1.
and a partially enlarged view of the valve disk 13 section.

With the above configuration, in the closed state where the valve disk 13 is seated on the inner and outer ring seats 8 and 10, a thin layer of water is formed not only on the valve disk 13 and the outer ring seat 10 but also on the valve disk 13 and the inner ring seat 8. It is also formed and maintained between the surfaces. That is, the inside of the annular narrow groove 14 communicates with the variable pressure chamber 7 side, and the steam that is about to leak from between the valve disk 13 and the inner ring seat 10 is depressurized in the narrow groove 14 and a part of it becomes condensed. Since water is supplied to the gap between the valve disk 13 and the inner ring seat 10 as shown in FIG. 3A, a water film is maintained and water sealed. Further, the steam on the side of the ejection hole 9 is supplied from between the valve disk 13 and the inner ring seat 8 into the variable pressure chamber 7 through the narrow groove 14 and the small hole 15, and the pressure within the variable pressure chamber 7 is maintained at high pressure. The valve remains firmly closed. Further, when there is condensate on the side of the ejection port 9, the valve is opened by a pressure drop in the variable pressure chamber 7, as in the conventional case.

In addition, the annular thin groove 14 acts as a labeling groove, increasing the passage resistance and increasing the annular groove 11 and the discharge hole 1.
This acts to prevent steam leakage to the 2nd side.

Furthermore, the annular narrow groove 14 acts to suppress the passage speed of condensate when the valve disk 13 is separated from the inner and outer ring seats 8, 10, and this type of groove 14 acts to suppress the passage speed of condensate when the valve disk 13 is separated from the inner and outer ring seats 8, 10. The strength of the valve disk 13 can also be increased by omitting or making the resistance groove shallower.

As described above, according to the present invention, steam leakage can be prevented when the valve disk is seated, and corrosion of the valve disk and inner ring seat can also be prevented.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a disk type steam trap according to an embodiment, FIG. 2 is a cross-sectional view taken along the line A--A in FIG. 1, and FIG. 3 is a partially enlarged view of only the valve portion in FIG. 1. 1 is the main body, 2 is an inlet passage, 3 is an outlet passage, 4 is an inner lid, 6 is a heat insulation chamber, 7 is a pressure transformation chamber, 8 is an inner ring seat,
9 is a jet hole, 10 is an outer ring seat, 11 is an annular groove, 12
is a discharge hole, 13 is a valve disk, 14 is a narrow groove, 15
is a pore, and 20 is an annular space.

Claims (1)

[Claims] 1. A disk-shaped valve disk that sits on and off from the valve seat surface consisting of an inner ring valve seat and an outer ring valve seat, and opens and closes the valve by automatically controlling it by pressure changes in a variable pressure chamber formed behind it. An annular narrow groove is formed on the inner ring valve seat surface, a small hole communicating between the narrow groove and the variable pressure chamber is formed at the lower part of the inner and outer ring valve seat surfaces, and a through hole is formed in the valve disk to pass through it. A disc-type steam trap that does not work.