JPS61157914A - Pressure reducing valve with drain valve - Google Patents

Abstract

PURPOSE:To advance surfacing of a float and opening of a valve and to reduce the amount of stagnant water by positioning the opening of a separation camber of the vent hole of a float cover for covering the float in the low pressure area of the center of a swirling flow. CONSTITUTION:The hollow spherical float 58 made of a metallic thin plate and the float cover 59 which is made of castings and covers the float 58 are disposed in a gas separation chamber 7. The central upper part of the cover 59 is formed protrusively, and the vent hole 61 is drilled thereon. The upper opening of the vent hole 61 is positioned in the low pressure part of the senter of the swirling flow. Here, when the pressure of an outlet 18 is lower than a set value, a main valve port 30 is opened. Then a gas at an inlet 38 passes through a screen 55, and is swirled by the swirling vane 47 of a bulkhead member 46. A water droplet is flipped outside to collide with the inner wall of the main body 8 of a separator case, and flows down along the wall. The gas reaches the lower space of the main valve port 30 through the inner opening of the water drip 50 of the member 46. The stagnant water in the separation chamber 7 is automatically discharged to a drain hole 64 from a drain valve port 63 by the action of the float 58.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a pressure reducing valve used to reduce the pressure of steam produced in a boiler and send it to steam-using equipment.

Water vapor condenses when cooled. When air is compressed, water condenses. Therefore, condensed water is always present in water vapor and compressed air systems. If this condensed water flows into the pressure reducing valve mixed with gas, hunting may occur, wear of the valve portion may be accelerated, or the pressure on the downstream side may rise beyond the set value (shutoff pressure increase).

Prior Art Therefore, the applicant has developed a pressure reducing valve in which a swirling type steam separator is installed on the upstream side of valve 1, and an automatic drain valve is placed at the bottom of the separation chamber.The automatic drain valve is a float valve. Although the valve is made of rock, it is designed to prevent the float from malfunctioning due to swirling flow.
Cover the float with a float cover. A vent is drilled in the upper peripheral wall of the float cover such that water enters the interior through the opening at the bottom of the float cover such that the gas inside is forced out of the vent and displaced.

In this case, when the main valve port opens and swirl occurs, the water accumulated at the bottom of the separation chamber becomes a concave water surface due to the swirl, and the water surface at the outer periphery rises. For this reason, it was necessary to make the separation chamber sufficiently elongated so that the separated water would not be transported from the main valve port to the outlet side again.

Means for Solving the Problems The technical measures of the present invention taken to solve these inconveniences are as follows: a) A swirling steam-water separator on the upstream side of the main valve port and a float on the bottom of the separation chamber. In a pressure reducing valve equipped with a type automatic drain valve, O) The separate air conditioning opening of the vent hole in the float cover that covers the float is located in the low pressure area at the center of the swirling flow.

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

The pressure reducing action of the pressure reducing valve is the same as the conventional one. When the main valve port opens, fluid flows from the inlet toward the main valve port. Along the way, it is rotated by swirling blades, and water droplets in the gas are taken out to the outside and separated from the gas in the center.

The inside of the float cover is connected to the center of the swirling flow through the ventilation hole, so when swirling begins, the pressure becomes low and the water at the bottom of the separation chamber is sucked into the float cover. Therefore, the water level at the bottom of the separation chamber lowers during swirling.

The float floats up and down along with the water level inside the float cover, opens and closes the drain valve, and drains water on its own.

Effect of the invention The present invention produces the following unique effects.

With the above-mentioned conventional float cover, in which the ventilation holes are opened in the upper peripheral wall, the water level inside the float cover becomes lower than the outside when the float turns, which delays the floating of the float and the opening of the valve, resulting in a large amount of water remaining. are doing.

According to the present invention, water on the outside of the float cover is sucked into the inside of the float cover when turning, so the float floats up and the valve opens more quickly, and the amount of retained water decreases.

Example (see Figure 1) An example will be described without showing a specific example of the above technical means.

The casing of the pressure reducing valve consists of a spring case 2 which houses a pressure setting spring, a pulp case 4 in which a pilot valve is arranged, a main body 6 in which a main valve 5 is arranged, and a separator case forming a steam/water separation chamber 7. It consists of a main body 8 and a bottom cover 9, which are made of cast metal.

A diaphragm made of a thin metal plate is sandwiched between a spring case 2 and a valve case 4. The upper space of the diaphragm is connected to the outside air, and the lower space is connected to the outlet 18 described below through a passage 33.

An adjustment screw 20 is attached to the ceiling wall of the spring case 2, and is prevented from rotating with a lock nut 21.

The inner end of the adjusting screw 20 contacts the upper end of the pressure setting spring.

The body 6 is formed with an inlet 28 and an outlet 18. The inlet 28 and the outlet 18 are separated by a horizontal wall 29 and connected through a main valve port 30 provided in the wall 29. The main valve 5 is located below the main valve port 30, and its upper end is connected to a piston 31.

The pilot valve has a passage 32 leading to the inlet 28 and a piston 3.
It is located between the passages 33 leading to the upper space of 1.

The piston 31 is a cylinder 4 attached to the inner circumference of the main body 6.
2, with two annular grooves around the outside, and
A spring 44 is placed inside the piston ring 43 made by E and the histone ring 43.

The piston ring 43 is made of PTFE and has low sliding resistance, reducing wear. It is also biased against the inner peripheral surface of the cylinder 42 by a spring 44, so that the piston 31 and cylinder 42
The space can be almost completely sealed.

Further, the piston 31 is provided with an orifice 45 that connects its upper and lower surfaces, and a certain amount of fluid on the upper surface of the piston 31 is released from the orifice 45 to control the pressure.

A partition member 46 is arranged in the space below the main valve port 30. The partition member 46 has an almost cylindrical upper part and a double cylindrical lower part. At the upper end between the double cylindrical parts there is approximately 3
The swirling feathers 47 are formed with an inclination of 0 degrees. A guide shaft 49 for guiding the lower part of the main valve 5 is formed on the central axis of the inner cylindrical portion via three glues 748.

A drainer 50 is formed by expanding the lower end of the inner cylindrical portion. The outer periphery 51 at the upper end of the inner cylindrical portion is tapered. The partition member 46 is integrally formed of lost wax, and the lower end of the outer cylindrical shape is connected to the main body 8 of the separator case.
The tapered part 51 of the upper end is fitted into the protruding tapered surface of the horizontal mold 29 and fixed on the central axis.

A carbon ring is attached to the outer periphery of the part of the main valve 5 that slides inside the guide shaft 49 and fixed with a snap ring, and a collar 54 with a clean inner peripheral surface is interposed between it and the guide shaft 49. , reduce sliding resistance. Valve body 5 and piston 31
Since they are separate bodies and guided by a guide shaft 49 and a cylinder 42, they will not get caught even if they are tilted.

A conical screen 55 is arranged around the outer periphery of the partition member 46.

The main body 8 of the separator case is attached to the main body 6 via a gasket 56 made of PTFE. The main body 8 of the separator case has a widened bottom, and a bottom cover 9 is attached to the bottom with a gasket 57 made of PTFE, and an air/water separation chamber 7 is formed inside.
form. A hollow spherical float 58 made of a metal Vs slope and a float cover 59 made of cast metal to cover it are arranged in the separation chamber 7.

The float cover 59 has an inverted cup shape, and a first
In the figure, the legs 60 are extended to the front and the other side of the page, downward and outward, and the outer ends of the legs 60 are fixed by being sandwiched between the main body 8 and the bottom cover 9 of the separator case. float cover 59
The central upper part of the is formed to protrude upward, and there is a ventilation hole 61 there.
open it. The upper end opening of the vent hole 61 is located in a low pressure region at the center of the swirling flow.

The water accumulated in the separation chamber 7 enters inside from the lower part of the float cover 59, and the gas inside is sucked out through the vent hole 61 and replaced. Since the float cover 59 is made of cast metal, it is sturdy and will not be deformed or damaged by swirling flow or water hammer. Since the ventilation hole 61 is provided in the upper center, the swirling flow allows the central part (lower pressure, so gas is easily sucked out,
Air and water replacement efficiency improves. Furthermore, since the vent hole 61 portion protrudes upward, gas is more likely to come out.

The bottom cover 9 is provided with a float seat 62 for determining the lowering position of the float 58 and a drain valve port 63. A drain valve port 63 is opened and closed by a float 58 to automatically drain water accumulated in a separation chamber 7 from a drain port 64.

The operation of the second embodiment will be explained. The pressure reducing action is the same as that of a conventional pressure reducing valve, so a description thereof will be omitted.

When the pressure at the outlet 18 becomes lower than the set value, the main valve port 30
will be held. Then, the gas at the inlet 28 passes through the screen 55.
, and is rotated by the swirling wings 47 of the partition member 46. The water droplets are thrown out and impact the inner wall of the main body 8 of the separator case, along which they flow downward. The gas passes through the inner opening of the drainer 5o of the partition member 46 and reaches the space below the main valve port 30.

The water accumulated in the separation chamber 7 is drained from the drain valve 6 by the action of the float 58.
3 to the drain port 64 automatically.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a pressure reducing valve according to an embodiment of the present invention. 7: Air-water separation chamber 18: Outlet 28: Inlet 30: Main valve lo 47: Swirl vane 58: 5 floats: Float force bar 61: Ventilation hole 64: Drain port

Claims (1)

[Claims] 1.In the case where a swirl type steam-water separator is placed upstream of the main valve port and a float type automatic drain valve is placed at the bottom of the separation chamber,
A pressure reducing valve with a drain valve, in which the opening on the separation chamber side of the air hole in the float cover that covers the float is located in the low pressure area at the center of the swirling flow.