JPH0786398B2 - Combination of automatic control valve and steam trap with valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention is a combination of a steam trap that automatically discharges only condensate from a steam piping system and a flow path switching valve, and the flow path switching The present invention relates to a combination of a steam trap with a valve in which the valve is operated by driving means such as an actuator, and an automatic control valve.

<Prior art> In order to control the temperature or pressure to be controlled in a steam-using device to a desired value, an automatic control valve is generally placed on the primary side of the steam-using device to control the temperature or pressure of the control target. Is provided, and the automatic control valve is operated so that the temperature or pressure to be controlled reaches a set value according to a detection signal from the device and an instruction from the controller. Then, a steam trap is installed on the secondary side of the steam-using equipment to automatically discharge only the condensate after heat exchange.

<Problems to be Solved by the Present Invention> The steam trap is a kind of automatic valve that automatically discharges only the condensate generated after the steam has performed its work. The design is considerably smaller than the. This is because the specific volume of the condensate is very small compared to the specific volume of the steam, and also the leakage of the steam is prevented as much as possible. Therefore, when a large amount of condensate is generated, such as when the steam-using device is initially started up, there is a disadvantage that the condensate stays only with the small valve opening. As a countermeasure against this, a bypass flow path with a pipe having a relatively large diameter is provided in parallel with the steam trap, and the flow path is also manually switched to the bypass flow path at the start of operation or at the initial startup. However, in this case, it is necessary to operate a plurality of valves in order to switch each flow path, and a large installation space is required to provide a bypass flow path.

Therefore, the technology of a steam trap with a built-in valve function is disclosed in Japanese Utility Model Publication No. 50-21962. This is because the flow passage switching valve is formed integrally with the trap in the trap body, and the normal passage trap function, the bypass flow passage function, and the closing function are exhibited by manually operating the flow passage switching valve. Is something that can be done. By integrally forming the trap and the flow path switching valve, the bypass flow path function can be obtained by the manual operation of one flow path switching valve, and the installation space due to piping is prevented from increasing.

However, even in the case of this technique, there is still the complexity of having to manually operate the flow path switching valve element. That is,
When the automatic control is performed as described above to reduce the set temperature or pressure, or when a steam trap with a valve is attached to a steam-using device of a batch system that repeatedly operates and stops, the bypass flow path is switched every time it is operated. Therefore, the manual operation of the valve body is required. In particular, this operation becomes very complicated when the interval between actuation and deactivation is short or when the frequency of switching is high.

Moreover, although the automatic control operation is performed by the automatic control valve, the ability is not sufficiently fulfilled, and the control is assisted by the manual operation of the valve. Further, there is a problem that the steam-using device cannot be operated at the highest efficiency and the productivity cannot be maximized.

Therefore, a technical object of the present invention is to eliminate the need for manual operation of the flow path switching valve and to achieve the maximum efficiency of steam-using equipment by controlling it in combination with an automatic regulating valve.

<Means for Solving the Problems> The technical means of the present invention taken to solve the above technical problems is an automatic method for controlling the pressure or the temperature of the equipment to be controlled on the primary side of the steam-using equipment. A steam trap with a valve in which a control valve is arranged, a flow path switching valve and a steam trap are integrally formed on the secondary side of a steam-using device, and the flow path switching valve can be operated by valve body driving means such as an actuator. The steam trap with valve is arranged so that the flow path switching valve opens and closes in conjunction with the control of the automatic control valve.

<Operation> The valve integrally formed with the steam trap is operated by driving means such as an actuator, and manual operation of the valve body is not required at all. Further, the valve body driving means is automatically operated so as to open and close in conjunction with the automatic control valve provided on the primary side of the steam-using device.

<Example> An example showing a specific example of the above technical means will be described.
(See FIGS. 1 to 3) In the present embodiment, as shown in FIG. 2, the automatic control valve 40, the steam-using device 42, the steam trap 44 with a valve, the pressure sensor 29, and the automatic control valve 40 are controlled. It is a steam heating system consisting of controller 28, controller 28,
The automatic control valve 40, the pressure sensor 29, and the steam trap with valve 44 are connected by signal lines. Reference numeral 30 is a setting input device. And the control target according to the present embodiment is the pressure of the steam supplied to the steam using device, and as the automatic control valve 40,
An automatic setting pressure reducing valve is used in which the pressure adjusting means of the pressure reducing valve described later is operated by a driving means such as an actuator.

First, the automatic setting pressure reducing valve 40 used as the automatic adjusting valve will be described with reference to FIG. An inlet 2 and an outlet 3 are formed in the main body 1 and connected to the primary side pipe 4 and the secondary side pipe 5. Entrance 2
And outlet 3 communicate with each other through valve opening 6. A main valve 7 that opens and closes the valve opening 6 is brought into contact with the piston 8, and the introduction of pressure to the upper surface of the piston 8 is controlled by the pilot valve 9. The pilot valve 9 is composed of a pilot valve seat 10 and a pilot valve body 11,
The pilot valve body 11 is biased upward by a spring arranged below it. The pilot valve 9 is located between the primary passage 12 and a passage 13 communicating with the space above the piston 8, and is operated by a diaphragm 15 elastically biased by a pressure setting spring 14.

The lower end of the pressure setting spring 14 is in contact with the upper surface of the diaphragm 15 via a spring bearing. The space above the diaphragm 15 is a passage
16 communicates with the outside air, and the lower space communicates with the outlet 3 through a secondary pressure detection passage passage 17. Therefore, the diaphragm
When 15 is displaced downward, the pilot valve body 11 is pushed down, the fluid at the inlet 2 is introduced above the piston 8 through the passages 12 and 13, and the main valve 7 is pushed down by the piston 8 to open the valve port 6. , The fluid at the inlet 2 flows to the outlet 3. Also,
When the secondary side pressure rises and the diaphragm 15 is displaced upward, the pilot valve body 11 is pushed up by the spring and the passage 13 is closed, and the piston 8 has a force that pushes down the main valve. The valve opening 6 is closed by being pushed up.

The lower end of the adjusting screw 18 contacts the upper end of the pressure setting spring 14 via a spring receiving member, and the compression amount of the pressure setting spring 14 is adjusted by the forward / backward movement of the adjusting screw 18 to cause an elastic force acting on the diaphragm 15. Is adjusted.

The actuator part is connected to the adjusting screw 18. The actuator section is composed of a motor 19, a speed reducer 20, a tension meter 21, and electronic components (not shown) for driving the motor 19.

The output shaft 22 of the speed reducer 20 and the adjusting screw 18 are spline-coupled. This spline fitting portion is provided with rollers 23a, b on a roller shaft that penetrates the output shaft 22 in the radial direction, forms the upper portion of the adjusting screw 18 in a cylindrical shape, and forms a groove 24a, b in the axial direction on the cylindrical portion. It is formed and the rollers 23a, 23b are fitted in the grooves. Therefore, when the output shaft 22 rotates from side to side,
The grooves 23a, 23b mesh with the grooves 23a, 23b to transmit the rotation to the adjusting screw 18. The adjusting screw 18 is axially displaced by the screw connection with the nut 25, and the displacement is absorbed by sliding in the grooves 24a, 24b. Reference numbers 26 and 27 are thrust bearings.

There is a functional relationship between the value (screw position) indicating the position of the tip of the adjusting screw 18 from the reference position and the degree of compression of the pressure setting spring 14, and thus the set pressure. It is stored in the microcomputer in 28 and the set pressure is input from the setting input device 30 to calculate the screw position, and the microcomputer controls the motor 19 so that the adjusting screw 18 takes this screw position. Set the pressure reducing valve to the set pressure.

In order to control the adjusting screw 18 to take a predetermined screw position, a screw position detecting device for the potentiometer 21 is provided, and the motor 19 is operated until the output signal from this device reaches the calculated screw position value.
To rotate. As another method of controlling the screw position, it is possible to control the number of pulses to be supplied to the stepping motor by using a stepping motor whose number of rotations is known to rotate when one pulse is supplied.

When the secondary side pressure reaches the target pressure, the motor 19 is stopped and thereafter the pressure reducing valve itself performs pressure control, but in the case of performing control with higher accuracy, a pressure sensor for detecting the pressure to be controlled-
29 is provided, and when a deviation from the set pressure occurs, a correction signal is continuously sent from the controller 28 to the motor 19 to perform the correction operation.

Next, the steam trap with valve 44 will be described with reference to FIG.

The flow path switching valve 50 and the steam trap 51 are airtightly coupled with the bolt 53 via the upper lid 52 to form a steam trap with a valve.

The flow path switching valve 50 is formed by a switching valve body 55 having a through hole 54 and a valve seat member 56. An inflow port 58 and an outflow port 59 are formed in the main body 57. A trap valve chamber 60 is provided in the main body 57 in communication with the inflow port 58.
And a substantially cylindrical strainer 61 with pores at the top
Is attached via a strainer attachment member 63 by a snap ring 62. The inside of the cylindrical strainer 61 is a valve seat member.
The valve inflow passage 64 provided in 56 communicates with the switching valve body 55.
The switching valve body 55 and the outflow port 59 are connected by the valve outflow passage 65, and the valve inflow passage
The bypass flow passage is formed by 64, the switching valve body 55, and the valve outflow passage 65.

Inside the trap valve chamber 60, a hollow float valve 66 that floats and descends according to the level of the condensate that flows in is arranged in a free state, and a trap valve seat 67 is attached to the lower part so as to project into the valve chamber. The trap valve port 68 provided in the trap valve seat 67 communicates with the outflow port 59 via the rising passage 69. Reference numeral 70 is a conventionally used bimetal that pushes up the float 66 at low temperature (state shown in FIG. 1) and does not participate at high temperature.

The switching valve body 55 has a cock shape, and a through hole 54 is provided substantially coaxially with the valve inflow passage 64 and the valve outflow passage 65, and is engaged with an operation rod 71 penetrating the inside of the upper lid 52 at the upper portion. The upper end of the operating rod 71 is connected to an output shaft 73 of a motor 72 as a valve body driving means. In addition to the above motor, the valve body driving means may be, for example, an air actuator that operates with compressed air, a hydraulic actuator, or the like. It rotates in the center of the output shaft 73 together with the output shaft 73, and it is manually operated separately from the rotation of the motor 72.
Attach the operation handle 74 so that the can be rotated. For this, a part of the output shaft 73 is chamfered, and a fitting hole that matches the facing portion of the operation handle 74 is provided for mounting.
A deceleration mechanism (not shown) for generating a torque required to drive the valve body 55 to rotate is built in the motor 72. A cord 75 for connecting the motor 72 to a power source (not shown) and various control devices (not shown) for switching the operation is attached to the motor mount 76.

A sequencer, a programmable controller, or the like can be appropriately selected as the various control devices for switching the operation of the motor 72. In this embodiment, a signal from the controller 28 is transmitted to the control unit 77 via the code 75 to drive and control the motor 72. Reference numeral 78 is a cover that protects the motor 72 and the control unit 77.

A plurality of disc-shaped bimetals 79 as heat responsive members are arranged below the switching valve body 55. Bimetal 79 is the first at low temperatures
As shown in the figure, it bends and pushes the switching valve body 55 upward. The switching valve body 55 is provided on the upper side of the switching valve body 55 via the sliding plate 80.
A coil spring 81 for urging the lower part is arranged. A space between the switching valve body 55 and the upper lid 52 is kept airtight by a packing 82. reference number
83 is a holding member for holding the packing 82, and is also 84
Is a sleeve that supports the rotation of the operating rod 71.

In the above configuration, when the temperature of the fluid flowing in from the inflow port 58 is low, both the bimetals 70 and 79 are curved as shown in FIG. 1, and the bimetal 79 is curved to push up the switching valve body 55 and A gap 85 is formed between the seat member 56,
The inflow port 58 communicates with the outflow port 59 through the valve inflow path 64, the gap 85, and the valve outflow path 65 to form a bypass flow path, and the bimetal 70 is bent to push up the float valve 66 and push the trap valve opening 68. Opens to expel cryogenic fluid. When the fluid temperature rises, the bimetal 79 becomes flat, and the switching valve body 55 is brought into close contact with the valve seat member 56 by the coil spring 81 so that the gap 85 disappears and the bypass flow passage is closed, and the bimetal 70 also becomes flat and participates in the float valve 66. Function as a normal steam trap, that is,
When the condensate does not flow in, the float valve 66 rises to open the trap valve port 68, and when steam flows in, the buoyancy of the float valve 66 disappears and the trap valve port 68 closes. Performs the function of discharging.

In the present embodiment, a cock is used as the flow path switching valve, and a float type is shown as the steam trap, but the steam trap is not limited to these.For example, a ball valve or a butterfly valve as the switching valve, As the steam trap, a disc type, a bucket type, a thermo type or the like can be used.

This system will be further explained based on FIG. 2. When the pressure in the pressure sensor 29 is low and the temperature is low when the steam-using equipment starts up, the controller 28 opens the steam trap with valve 44 to open the steam trap. Is output, the motor 72 drives and the operating rod 71 rotates 90 degrees from the state shown in the figure. Then, the through hole 54 of the switching valve body 55 communicates with the valve inflow path 58 and the valve outflow path 59 to automatically form a bypass flow path, and the residual air and low-temperature condensate in the steam-using device 42 are forcibly discharged. It Further, in this case, foreign matters such as dust and scale accumulated inside the strainer 61 can be removed outside the device together with the fluid in the bypass flow passage. At this time, since the fluid is low in temperature, the bypass passage is further opened by the action of the bimetal 79 as described above to help discharge the fluid.

As another control method, when the set pressure of the steam-using device 42 is changed during steady operation, for example, when the set pressure is lowered, the pressure inside the device must be lowered early. At that time, in the computer in the controller 28, when changing the set pressure to a value lower than the current set pressure, a program is input so that the flow path switching valve 50 of the steam trap with valve opens. The set pressure can be approached faster.

Also, even if steam-using equipment performs batch operation, if one batch is completed, the flow path switching valve 50 of the steam trap with a valve can be opened so that the operation cycle can be accelerated by forced blow. You can

<Effects of the Invention> It is not necessary to manually operate the bypass valve or the flow path switching valve, and automatic control can be performed to obtain the maximum efficiency of the steam-using device.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an embodiment of a steam trap with a valve of the present invention, FIG. 2 is a system diagram of a steam using apparatus shown in the embodiment, and FIG. 3 is an automatic setting pressure reducing valve shown in FIG. FIG. 40: Automatic setting pressure reducing valve, 42: Steam-using device 44: Steam trap with valve 50: Flow path switching valve, 51: Steam trap 55: Switching valve body, 56: Valve seat member 58: Inlet port, 59: Outlet port 66 : Float valve

Claims (1)

[Claims] 1. An automatic control valve for controlling the pressure or temperature to be controlled by the device is arranged on the primary side of a steam-using device,
On the secondary side of the steam equipment, a flow path switching valve and a steam trap are integrally formed, and a steam trap with a valve is arranged so that the flow path switching valve can be operated by a valve body driving means such as an actuator. A combination of an automatic control valve and a steam trap with a valve, wherein the flow path switching valve of the trap is opened and closed in conjunction with the control of the automatic control valve.