JPH0781689B2 - Pressure reducing valve for steam - Google Patents

Description

Description: INDUSTRIAL APPLICABILITY The present invention is attached to a steam pipe and controls the flow rate of steam flowing from the primary side to the secondary side to set the steam pressure on the secondary side to a predetermined value lower than that on the primary side. In particular, the present invention relates to a pressure reducing valve for steam that improves the quality of secondary pressure reducing steam, that is, the dryness of steam.

In order to use steam-using equipment such as heat exchangers efficiently, the steam to be supplied is preferably saturated steam with 100% dryness or superheated steam, but in reality, even if steam that is close to saturation is generated in the boiler, it is sent. It becomes wet steam that contains condensed water due to heat dissipation during the period.

In addition, the generated condensate causes a water hammer, which damages pipes and connecting devices and causes corrosion.

Conventional technology Condensate generated when high-pressure steam generated in a boiler is sent to the destination of use, is removed to the outside of the system with a steam separator or steam trap in the middle of the piping, or a pressure reducing valve in front of the equipment is used to achieve an appropriate pressure. It was dealt with by reducing the pressure.

When the pressure reducing valve operates, part of the high-temperature high-pressure condensate contained in the steam on the primary side re-evaporates in the low-pressure region on the secondary side, so some condensate is automatically processed. It was

Problems to be Solved by the Invention Even if a steam-water separator for normal steam can separate condensed water in the form of droplets, it is difficult to separate condensed water in the form of mist, and saturated steam There is a problem that can not be.

Further, not all of the condensate can be re-evaporated depending on the amount of condensate even if it is re-evaporated by the depressurizing action. Furthermore, when the pressure reducing ratio of the pressure reducing valve is small, the re-evaporation rate is so small that part of the condensate cannot be re-evaporated and remains as it is.
It cannot be saturated steam.

Therefore, a technical problem of the present invention is to reliably convert wet steam containing condensate into saturated steam or slightly superheated steam by a pressure reducing valve in order to increase production efficiency of steam-using equipment.

Means for Solving the Problems Technical means of the present invention taken to solve the above problems are:
The steam on the inlet side of the pressure reducing valve is introduced into the vortex tube through the introduction hole, separated into high temperature steam and low temperature steam by the vortex tube, and the high temperature steam is communicated with the inlet side or the outlet side of the pressure reducing valve. By exchanging heat with the passing steam, the passing steam can be converted into saturated temperature steam or superheated temperature steam.

The vortex tube is conventionally well-known as described in, for example, Japanese Utility Model Publication No. 45-4196, and a vortex flow is generated in the cylindrical tube by blowing a compressed gas at a high speed in the tangential direction of the cylindrical tube and the vortex The airflow separates into a low-temperature airflow and a high-temperature airflow while swirling. Steam as compressed gas from the inlet side of the pressure reducing valve enters the vortex tube from the introduction hole and is separated into high temperature steam and low temperature steam.
The steam separated by the vortex flow and becoming hotter than the inlet side,
Exchange heat with passing steam at the inlet or outlet of the pressure reducing valve,
The passing steam is converted into saturated temperature steam or superheated temperature steam.

The low-temperature steam separated by the vortex tube may be released to the atmosphere, or may be used separately at a place where the low-temperature steam is used.

EFFECTS OF THE INVENTION Due to the high-temperature steam separated by the vortex tube, the steam that has passed through the pressure reducing valve is reliably saturated steam or superheated steam, and the production efficiency of steam-using equipment can be increased.

Further, by combining the pressure reducing valve and the vortex tube, the wet vapor can be more surely made into saturated vapor or superheated vapor by the pressure reducing action of the pressure reducing valve and the temperature raising action of the vortex tube.

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

The steam pressure reducing valve of this embodiment includes a pressure reducing valve portion 1, a steam separator 2 and a drain valve portion 3. The main body 10 forms an inlet 12, a valve opening 14, and an outlet 16. The inlet is connected to a hot steam source on the primary side.

The main valve body 18 is arranged at the inlet side end of the valve seat 15 forming the valve opening 14 while being elastically biased by the coil spring 9. The piston 20 is slidably arranged in the cylinder 22, and the piston rod 17 is connected to the main valve body 18.
Abut the central protrusion of. The lower surface of the piston (20) and the piston rod (17) are connected by a substantially hemispherical surface, and an escape hole (33) is provided in the piston (20). A primary pressure passage that connects the inlet 12 and the upper space of the piston 20, that is, the piston chamber 8 via a communication passage 32.
The pilot valve 26 is arranged in the valve 24 with the coil spring 31 urging the valve closed. The space below the diaphragm 28 communicates with the outlet 16 through the secondary pressure passage 34. The head end surface of the valve rod 36 of the pilot valve 26 abuts the central lower surface of the diaphragm 28.

A coil spring 40 for pressure setting is brought into contact with the upper surface of the diaphragm 28 via the spring seat 7. The adjustment screw 44 is screwed and attached to the main body 10. Turn the adjusting screw 44 left and right,
The elastic force that pushes down the diaphragm 28 of the pressure setting spring 40 changes. With the elastic force of the pressure setting spring 40 as a reference value, the diaphragm 28 bends according to the secondary pressure acting on the lower surface of the diaphragm 28, and the valve rod 36 is displaced to open / close the pilot valve 26. As a result, the primary side fluid pressure is introduced into the piston chamber 8, the piston 20 is driven, the main valve body 18 is displaced, and the fluid at the inlet 12 flows through the valve opening 14 to the outlet 16.
When the fluid pressure on the secondary side drops, the valve port 14 opens, and when it rises, it automatically closes.

A cylindrical partition member 46 is attached below the valve opening 14, and an annular space 48 is formed between the partition wall member 46 and the main body 10 that surrounds the partition wall member 46, the upper portion of which communicates with the inlet 12 through the cone-shaped screen 50, and the lower portion of the drain valve. It communicates with the upper part of the chamber 52. Further, the upper part of the drainage valve chamber 52 communicates with the valve port 14 through the central opening 6 of the partition member 46. A swirl vane 54, which is an inclined wall, is arranged in the annular space 48.

The wet steam containing the condensate from the inlet 12 is swirled by the swirling vanes 54 when the valve port 14 opens and passes through the annular space 48. The large-mass droplet is swung outward and hits the inner wall of the surrounding body to flow down to the drainage valve chamber 52, and the light steam swirls in the central portion, goes from the central opening 6 of the partition member 46 to the valve opening 14, and exits. Run down to 16.

A vortex tube 61 having an introduction hole 60 is arranged at the lower end of the partition member 46. The vortex tube 61 is the second
As shown in FIGS. 3 and 4, a steam introducing hole 60 is formed in a lower portion having a cylindrical portion 70 having a substantially cylindrical cross section, and a plurality of introducing grooves 62 (see FIG. 3) are formed in communication with the introducing hole 60. The low temperature steam extraction passage 63 is provided at the lower end, and the high temperature steam extraction passage 64 is provided at the upper end. The wet steam containing mist-like water swirled by the swirl vanes 54 enters the vortex tube 61 from the steam introduction hole 60, and is swirled further in the cylindrical portion 70 to be separated into high-temperature steam and low-temperature steam. . High-temperature steam is located inside the cylindrical portion 70 of the vortex tube 61, and the wet steam passing through the inside of the partition member 46 via the cylindrical portion 70 is heated to become saturated steam or superheated steam. The heat-exchanged high-temperature steam reaches the valve port 14 through the high-temperature steam extraction passage 64. The low-temperature steam is located in the center of the cylindrical portion 70, and the drainage valve chamber 52 below is provided via a cooling pipe 71 (see FIG. 1) communicating with the low-temperature steam extraction passage 63 of the vortex tube 61.
Be led to.

A drain valve port 58 communicating with a drain port 56 is formed at the bottom of the drain valve chamber 52. It is covered with a float cover 62 to accommodate the spherical valve float 80 in a free state. The cooling pipe 71 from the vortex tube 61 is coiled and arranged on the outer circumference of the float cover 62 to cool the high-temperature condensate accumulated in the drain valve chamber 52.

The valve float 80 floats down along with the water level in the drainage valve chamber 52 to open and close the drainage valve port 58, and automatically removes the condensed water accumulated in the drainage valve chamber 52. In this case, the condensate in the drain valve chamber 52 is cooled by the cooling pipe 71.
Since it is cooled by, it is less likely to be re-evaporated even if it is discharged from the drain port 56, that is, the re-evaporated steam in a steamy state is less likely to be generated, therefore,
It is not mistaken for the steam to leak from the drain valve port 58, and the adverse effect of the re-evaporated steam on the surrounding environment is eliminated.

When the wet steam containing the mist-like residual condensate passes through the inside of the partition member 46, it becomes saturated steam or superheated steam due to the high temperature steam from the vortex tube 61, so that the production efficiency of steam-using equipment can be kept high. You can

In this embodiment, one vortex tube 61 is shown, but a plurality of vortex tubes 61 may be provided depending on the required dry steam or superheated steam.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of a pressure reducing valve for steam according to the present invention.
1 is a sectional view of the vortex tube in FIG. 1, and FIG. 3 is a sectional view taken along the line AA 'in FIG. 1: Decompression valve part, 2: Steam separator part 3: Drain valve part, 12: Inlet 14: Valve port, 16: Outlet 20: Piston, 26: Pilot valve 28: Diaphragm, 46: Partition member 54: Swirling blade , 60: Introduction hole 61: Vortex tube 63: Low temperature steam extraction passage 64: High temperature steam extraction passage 70: Cylindrical part, 80: Valve float

Claims (1)

[Claims] 1. A steam on the inlet side of a pressure reducing valve is introduced into a vortex tube through an introduction hole, separated into high temperature steam and low temperature steam by the vortex tube, and the high temperature steam is communicated to the inlet side or the outlet side of the pressure reducing valve. A steam pressure reducing valve that converts the passing steam into saturated temperature steam or superheated temperature steam by exchanging heat with the passing steam of the pressure reducing valve.