JPH0536151Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention relates to a control valve that is attached to steam-using equipment or steam piping and maintains the steam pressure and temperature on the secondary side at a desired value, especially when the valve is repeatedly activated and deactivated. This invention relates to a steam control valve suitable for batch processing.

Control valves normally control the flow rate with the gap between the valve seat and the valve body narrowed considerably, and if the opening area changes, the flow rate value also changes.

BACKGROUND ART As an example of a conventional steam control valve, one shown in FIG. 3 has been used. This is entrance 10
A valve seat 12 and a valve body 13 are arranged between the outlet 11 and the outlet 11,
The opening area of the valve port 14 is adjusted by vertically operating an operating rod 15 connected to the valve body 13 from outside the valve, thereby controlling the amount of steam supplied to the outlet 11 side.

The opening area is precisely adjusted by the conical surface portion 16 at the bottom of the valve body 13.

Problems to be solved by the present invention There are two ways to use a control valve whose opening area has been adjusted: continuous processing, in which steam is constantly supplied, and batch processing, in which steam is repeatedly supplied and stopped.In the case of batch processing, the control valve is controlled each time. Since adjusting the opening degree of the valve is complicated or the adjustment value may deviate, supply and stop are usually performed using a separately provided on/off valve, and the opening degree of the control valve is kept constant. In the case of batch processing, if the opening degree of the control valve is adjusted in a narrowed state, it will take time for the low-temperature condensate and air that has accumulated until then to flow down when the next steam is supplied, and the steam-using equipment will start up. There was a problem that caused a delay in uploading.

The technical problem of this invention is to allow low-temperature condensate and air to quickly flow down in a steam control valve so as to avoid delays in starting up steam-using equipment, and to provide steam that has normal control characteristics when supplying steam. The goal is to obtain a control valve for use.

Means for Solving the Problems The technical means of the present invention taken to solve the above technical problems is to arrange a valve seat and a valve body between the inlet and the outlet, and operate the valve body from the outside of the valve with an operating rod. In a control valve that obtains desired flow characteristics by adjusting the distance between the valve body and the valve seat by operating the control valve, the operating rod is fixed to the sub-valve, and the main valve has the desired flow characteristics in the sub-valve. A temperature-responsive member is placed between the main valve and the auxiliary valve so that the main valve enters the auxiliary valve when the temperature is low, and the main valve protrudes from the inside of the auxiliary valve toward the valve seat when the temperature is high. .

Effect The operation of the above technical means is as follows.

Since the operating rod is fixed to the sub-valve, the position of the sub-valve relative to the valve seat remains constant unless the operating rod is operated to change the opening degree of the control valve. When low-temperature drain or air flows into the control valve, the temperature-responsive member moves the main valve into the sub-valve, and the valve opening becomes large between the sub-valve and the valve seat. When high-temperature steam flows in, the temperature-responsive member causes the main valve to protrude from the sub-valve to exhibit desired flow characteristics.

Effects of the invention When low-temperature fluid flows in, the opening of the control valve increases, and when high-temperature fluid flows in, the main valve with the desired flow rate control characteristics protrudes. It is possible to obtain a steam control valve that allows the accumulated low-temperature condensate and air to quickly flow down during the next use of steam, thereby eliminating any delay in startup, and that also has normal control characteristics when steam flows in.

Embodiment An embodiment illustrating a specific example of the above technical means will be described (see FIGS. 1 to 3).

The overall configuration of the control valve is the same as the third example shown in the conventional example.
It is the same as the figure, the same members are given the same reference numerals, and detailed explanation of the control valve will be omitted.

Fig. 1 shows the state at high temperature, and Fig. 2 shows the state at low temperature.
are formed into one. The sub-valve 1 is formed in a substantially cylindrical shape with its lower end open. Further, a plurality of through holes 20, 21, 22 are provided on the side surface of the sub-valve 1 all around the circumference. The sub valve 1 has an approximately inverted triangular cross section and a conical surface 16 on the lower surface.
A main valve 2 having a main valve 2 is disposed. A stepped portion 3 is provided on the upper surface of the main valve 2, and a coil-shaped bimetal 4 as a temperature responsive member is disposed between the stepped portion 3 and the auxiliary valve 1. As the temperature responsive member, shape memory alloys other than bimetals, thermowaxes, bellows, etc. can also be used. Bimetal 4 expands at high temperatures (first
Condition shown in the figure) The main valve 2 is made to protrude from the sub-valve 1,
At low temperatures, the main valve 2 contracts (the state shown in Figure 2).
is placed in the sub-valve 1. A flange portion 5 is provided on the upper side surface of the main valve 2, and a coil spring 6 is disposed between the flange portion 5 and the lower end step portion 7 of the sub-valve 1 to bias the main valve 2 in the direction of the operating rod 15. Reference number 12 is a valve seat.

When the steam supply is stopped and low-temperature drain or air is generated, the bimetal 4 contracts (the state shown in Fig. 2) and reduces the distance (section B) between the main valve 2 and the valve seat 12, that is, the opening area. Make it large and allow low temperature drain and air to flow down quickly. When high-temperature steam flows in after the low-temperature fluid has flowed down, the bimetal 4 expands (the state shown in Figure 1), the main valve 2 protrudes, and the distance from the valve seat 12 (section A) is narrowed, reducing the once adjusted flow rate. control.

In this embodiment, the shape of the main valve is conical, but other shapes of conventionally used control valve bodies, such as a linear valve body or an equal percentage valve body, may be used.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the main parts of the embodiment of the steam control valve of the present invention showing the state at high temperatures, Fig. 2 is a sectional view of the main parts showing the state of the present embodiment at low temperatures, and Fig. 3 is a sectional view of a conventional control valve. 1...Sub-valve, 2...Main valve, 4...Bimetal,
5...Brim portion, 6...Coil spring, 10...Inlet, 11...Outlet, 12...Valve seat, 15...Operation rod, 16...Conical surface.

Claims (1)

[Scope of utility model registration request] A control valve in which a valve seat and a valve body are arranged between an inlet and an outlet, and the valve body is operated from outside the valve using an operating rod to adjust the distance between the valve body and the valve seat to obtain desired flow characteristics. In this method, the operating rod is fixed to a sub-valve, and a main valve having desired flow characteristics is fitted into the sub-valve, so that the main valve enters the sub-valve when the temperature is low, and the main valve moves from the sub-valve to the valve seat when the temperature is high. A steam control valve characterized in that a temperature-responsive member is disposed between a main valve and a sub-valve so as to protrude to the side.