JPS59183192A - Intermittent water repellency regulator for temperature sensitive working steam trap - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Generally, a so-called steam trap is connected to a steam piping system to remove condensate generated by condensation of the steam.

Steam traps can be divided into various operating types to suit the conditions of condensate generation, but (in trace piping, that is, generally in the petrochemical industry etc., steam traps are buried in the heat insulating coating layer of oil pipelines, etc.). Bimetallic steam traps, which have excellent temperature sensitivity, are often used to remove condensate from steam piping that controls the heating of roadway fluids.

In other words, the amount of condensate generated in the trace piping is almost constant except for the initial stage of ventilation, and therefore the temperature gradient leading to the condensate temperature set by the bimetal is maintained, and the condensate is continuously generated under a stable valve opening of the steam trap. This is because the water discharge is maintained at a specific temperature, and the heating and washing of the oil pipeline by means of trace piping is maintained unchanged and properly.

However, such continuous drainage is difficult when the condensate discharge temperature is relatively low, but when operation under high temperature and high pressure is required, the high temperature and high pressure condensate that flows out of the valve port is violently re-evaporated, resulting in low temperature condensation. Since the flow velocity is extremely high compared to the above, this combined with the high temperature environment, which is disadvantageous in terms of the material of the valve and valve seat members, is extremely disadvantageous in terms of erosion and other durability of the steam trap.

In this regard, we conducted research and development aimed at regulating the operation of temperature-sensitive steam traps, of which the bimetal type described above is a typical example, at high temperatures and high pressures to control intermittent drainage. This means that the objective can be solved advantageously.

First, the prerequisite is that the valve holder is fixed to the valve holter, which is subjected to the action of the thermal expansion thrust acting in the opening/closing direction and the counterforce of the coil spring, so as to be relatively movable only in the direction of the reaction force of the spring. The object of this study is a temperature-sensitive steam trap that is installed opposite to a fixed valve port that selectively discharges water as the temperature of the condensate, which originates from the thermal expansion thrust, decreases.

In order to comply with the above regulations, it is recommended that this trap be provided with a one-way valve with a self-closing tendency that opens in response to the action of condensate pressure passing through the valve port on the downstream side of the fixed valve port. This is an essential requirement.

This one-way valve does not open even when the heat-sensitive valve is slightly opened, and allows wastewater to flow out only after the valve opening has expanded sufficiently, and as a result of the flow, a reverse reaction occurs. When the opening of the valve is reduced by the heat-sensitive operation of the valve, a pre-seating occurs just before the valve closes, regulating the drainage between the steam traps and preventing the high-speed flow of condensate at minute openings. This helps effectively avoid erosion.

Now, as an example, FIG. 1 illustrates a cross section of a bimetallic steam trap that controls intermittent drainage in a closed state.

In the figure, 1 is a body, 2 is an inlet, 3 is an outlet, 4 is a partition, 5 is a bonnet, 6 is a gasket, and 7 is a cap.

In this example, a hollow base member 8 is screwed and fixed to the partition wall 4 to communicate between the inlet and outlet 2 and 3, and a cylindrical valve seat 9 is further screwed into the base member 8 and a coil spring 10 surrounding it. is arranged to support a valve holder 11 that is movable up and down inside the valve seat 9.

The valve holder 11 has a hollow cylindrical shape with a flange, the flange 12 of which is used as a spring seat, and a number of holes 13 opened in a spider shape on the top surface, which are arranged on the sliding surface with the inner periphery of the cylindrical valve seat 9. A semicircular groove 14 is formed in the center hole 15, and an inward flange 1 is formed at the bottom of the central hole 15.
6 will be provided.

The inward facing flange 16 has a top flange engaged therewith and supports a conical valve 17 in the central hole 15;
A bushing 18 is engaged with the upper end of the central hole 15.

The bushing 18 supports the lower end of a thrust stem 20 that supports the bimetal column 19 in a skewered manner, and its upper end is held within the end opening of an adjustment screw 21 that passes airtight through the center of the top wall of the bonnet 5. The adjusting screw 21 is screwed into the cap screw sleeve 23 of the gland packing 22.

Furthermore, as shown in detail in Figure 2, the top tsuba of the valve 17 has a
It is preferable that the receiver is provided with a coil spring 24 between it and the bush 18, and a short iron 25 with a gap between it and the stem 20. Further, in the figure, 26 is a retaining ring for the bimetal column 19, and 27 is a washer that can be sandwiched between a pair of bimetals with their low expansion sides facing inward.

In the known configuration of the solid bimetallic steam trap described above, when starting ventilation into the steam piping system, the flat metal column 19 shown in FIG.
The repulsive force of the coil spring 10 acting on the valve holder 11 pushes up the valve holder 11, and as a result, the valve 17 is separated from the valve hole 28 of the valve seat 9, so that the air in the piping system under ventilation pressure, and then the initial stage of tracking this. The condensed water is removed from the valve hole 28, and the metal column 19 expands and deforms as shown in FIG. 1 due to the subsequent arrival of high-temperature condensate.
The valve holder 11 is pressed against the coil spring 10 through the coil spring 10 and pushed down, thus causing the valve 17 to close, and then the temperature of the condensate decreases due to heat radiation from the bonnet 5, and the thermal expansion thrust of the metal coum 19 decreases. As a result, the restoring force of the coil spring 10 causes the valve 17 to open and separate, causing condensate to be released again several times, but eventually the condensate temperature gradient in the steam piping system increases. As mentioned earlier, the reason why water continues to drain continuously under a certain opening degree of the valve 17 (determined by the temperature setting with the adjusting screw 21) after reaching a constant value is that the steam in the piping system is As already explained, when the pressure is high, there are problems associated with it.As an effective means to avoid this problem, as shown in FIG.
A second valve port 29 is provided at the second valve port 29, and a one-way valve 31 that opens under the action of the internal pressure of the condensate passage 30 that has passed through the valve hole 28 is disposed on the second valve port 29. The one-way valve 31 in this example has a stem 34 that loosely passes through a hollow free piston 33 which can be raised and lowered within the lower skirt portion 32 of the base member 8, and which faces the stem 34 to define the lift of the one-way valve 31. A weak coil spring 36 is built in between the stopper 35 screwed into the end of the lower skirt 32 and the hollow free piston 33, so that it has a self-closing tendency. 37 in the figure is a spider hole drilled in the stopper 35.

The one-way valve 31 closes the second valve port 29 by the biasing force of the coil spring 36 acting via the hollow free piston 33, and maintains this closure even when the valve element 17 is slightly opened.゛When the opening degree becomes sufficiently large, as soon as the one-way valve 31 opens due to the pressure of the condensate in the passage 30 passing through the valve hole 28 (static pressure and dynamic pressure), the condensate opens. The water pressure acts on the entire pressure receiving area of the hollow free piston 33 and pushes it down, and from the gap between the stem 34 of the one-way valve 31 and the hollow hole of the hollow free piston 33, which opens, the spider hole 37 The flow of wastewater is directed through.

Due to this condensate discharge, the temperature of the condensate arriving at the inlet 2 gradually increases, and as a result of the expansion of the bimetal column 19, the valve holder 11 pushes down the coil spring 10 as already mentioned, and the valve element 17 is then pressed against the valve seat 9. The approach passes through the valve hole 28. As the condensate flow begins to be restricted 1, the condensate pressure in passage 30 decreases and one-way valve 31
Due to its self-closing tendency, the second valve port 29 is closed before the valve hole 28 is closed by the valve element 17, and thus the valve element 17 closes the second valve port 29.
Since the valve closes slowly, erosion, which is a concern when the high-speed discharge flow continues under the minute opening, is avoided.

In the example shown in FIG. 2, the end face opening of the valve seat 9 downstream of the valve hole 28 is used as the second valve port 29, and the stem 34 is loosely attached to the end face opening of the valve seat 9 downstream of the valve hole 28. At t, a variant is shown in which the hollow free piston is omitted, so that the spring 36 acts, and in this case, in much the same way as already mentioned, the continuous drainage action through the valve hole 28 is interrupted in a timely manner; Intermittent drainage regulations will be achieved.

As described above, the continuous drainage operation of the temperature-sensitive steam trap can be regulated to intermittent operation that is more appropriate at high temperatures and high pressures, using a simple configuration that includes the addition of a one-way valve with a self-closing tendency. Can be done.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a bimetallic steam trap in a closed state, and FIG. 2 is a cross-sectional view showing the details of the internal structure of another example. 11... Valve holder 28... Fixed valve hole 29
... Second valve port 31 ... One-way valve Patent applicant name Miyawaki Steam Trap Manufacturing Co., Ltd. Figure 1 Figure 2

Claims (1)

[Claims] The valve element, which is relatively movable only in the direction of the reaction force of the spring, is fixed to the valve holder which is subjected to the action of the thermal expansion thrust acting in the valve closing direction and the reaction force of the coil spring opposing this. A temperature-sensitive steam trap is installed opposite to a fixed valve port that controls selective drainage as the temperature of the condensate derived from the expansion thrust decreases, and the valve port is installed on the downstream side of the fixed valve port. An intermittent drainage control device for a temperature-sensitive steam trap, further comprising a one-way valve with a self-closing tendency, which opens under the action of the condensate pressure passing therethrough.