JPH0517440B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <<Industrial Application>> The present invention relates to a separation valve for discharging a liquid phase from a two-phase fluid under pressure, and more specifically to a separation valve for discharging a liquid phase from a two-phase fluid under pressure. a valve seat or valve seat ring having a port fixed to the drain passageway and communicating with the discharge passage; The present invention relates to a separation valve having a mating valve body and means for controlling opening of the valve body in response to a liquid phase water level in a chamber.

<<Prior art and its problems>> The present invention was developed in the process of operating a steam piping network for urban heating. The steam supply has a maximum temperature of approx.
It is carried out at 235° C. and an effective pressure of 21 to 5 bar, depending on the region of supply. If the amount of steam supplied is small or the pressure in the pipes increases rapidly, the steam will reach saturation and condensation will begin, but this condensate must be drained to keep the steam dry.

A water storage tank called a drain bottle is connected at the bottom to the separator and is placed at a low point in the piping network or at an intermediate point of a long, uniformly sloped piping.

The separator is usually a so-called closed float type separator, and has a valve communicating with a discharge passage in a chamber communicating with the drain bottle. This drain is typically a condensate return line. The valve is biased into a closed position by the pressure created in the chamber and opened by a float actuated via a lever. When the condensate reaches a predetermined level in the chamber, the float opens the valve and the condensate is discharged into the drain until the water level drops and the valve is closed.

This device typically has a thermostatic valve for venting noncondensable gases. When only condensate and steam are in the room, the cooling is offset by the steam condensate, so the room is kept at approximately the steam temperature. When noncondensables are present in the steam, the equilibrium temperature of the chamber is determined by the condensate temperature of the steam at the partial pressure in the chamber. The thermostatic valve remains open at lower temperatures until the noncondensables have been exhausted.

As for the condensate discharge valve, this valve operates under very harsh conditions. The valve is typically immersed in condensate at temperatures above 200° C., which consists of pure but highly corrosive water and may even be contaminated with ammonia. Also, since this valve discharges the emulsion of water and steam at high speed, some of the condensate is re-evaporated due to the condensate restriction at the valve port.
It is highly erosive. Furthermore, if the pressure in the pipe network drops when the amount of steam supplied is high, the condensate in the room will re-evaporate and the blocked valve will be exposed to dry, intense steam.

Sealed float isolation valves generally consist of a ball coupled to one end of a lever and a valve seat with an annular port into which the ball engages, the other end of the lever carrying a float; By providing a predetermined amount of play between the ball and the lever to which it is coupled, the ball can be accurately engaged with the port.

This valve must have a first-class seal in the closed position. In practice, one ton of steam costs between 60 and 100 French francs due to the necessary treatment of the feed water for the steam generator and the enthalpy of the steam (of the order of 2.79 gigajyules per ton). However, even the best separators currently on the market lose about 3 kg of steam per hour. This corresponds to approximately 7 c.c. per second at 10 bar, or 0.8 cc per second. This amount may not seem like much, but in one year, 26 tons of steam, or
The equivalent of 2,000 French francs would be lost. This amount is almost the same as the price of the separator.

It is very difficult to precisely analyze the causes of loss of sealing performance in separators operating at temperatures of about 200°C and pressures of up to about 20 bar. This is because it is difficult to observe during operation and because the valve is small. Regarding the latter, in order to make the entire separator a reasonable size, it is necessary to use a float of several hundred cc at the end of a lever of approximately 20 cm. In order to press the valve body against the port by operating the float under the pressure of the separation chamber, the opening diameter of the port should be set to 5.
mm or less, the movement distance of the valve body must be in millimeters.

The reason why conventional separators have relatively poor sealing performance is that the condensate during separation is discharged at high speed, so there is an impact between the valve body and the valve seat at the time of blockage, and the ball does not fit properly. This seems to be because it does not engage the center of the port. In particular, if the ball does not accurately engage the center of the port during closure, distortion will occur near the outer periphery of the port due to wear.

To explain the above in more detail, the conventional separator shown in FIG. 1 has a chamber 1 that communicates with a drain bottle (not shown) through an opening 2. The condensate discharged from the pressurized steam piping network is collected in this drain bottle and then flows into the lower part of the chamber 1.

The separator has a valve located below the water surface of the condensate 7,
This valve consists of a ball-shaped valve body 3a and a valve seat 3b. The ball valve 3a engages the valve seat 3b under the control of means responsive to the level of the condensate 7. This means has a float 5 disposed at the tip of a first lever arm 5a, while a ball valve 3a is disposed at the tip of a second lever arm 5b extending substantially at right angles to the first lever arm 5a. Ru.

At the end of the valves 3a and 3b, there is a conduit 4 that communicates with the discharge path.
is drilled. The discharge line is the return line of the steam supply network and returns the condensate to the steam generator.

In the upper part of the chamber 1 there is provided an outlet 6 for discharging noncondensables, which outlet 6 is usually equipped with a thermostatic valve. Since the steam fills the space above the condensate 7 and is in equilibrium with the condensate on the one hand and the supply pipe network on the other hand, it is necessarily very sensitive to the supply temperature. However, if non-condensables such as air enter the chamber 1 above the condensate 7 for some reason,
These tend to be cooled in contact with the walls. At that time, the thermostatic valve opens and the uncondensables are discharged, and the thermostatic valve is once again surrounded by steam.

When the water level of the condensate 7 reaches a predetermined value in the chamber 1, the hydrostatic pressure acting on the float 5 at the tip of the first lever arm 5a exceeds the pressure applied to the ball valve 3a at the tip of the second lever arm 5b. . Therefore,
Valves 3a, 3b are opened and the condensate is discharged into conduit 4 by the pressure in chamber 1.

What should be noted is that when the ball valve 3a retreats a considerable distance, the compression thrust difference between the front and rear of the ball valve 3a becomes small, and the hydrostatic pressure of the float 5 is limited to an amount equivalent to its weight. , tends to rise from the condensate 7. The difference in water level between the open and closed positions of the valve is considerable, and a relatively large amount of condensate is discharged in one operation. In the final stage when the valves 3a, 3b are closed, the pressure difference between the front and rear of the ball valve 3a increases, and the hydrostatic pressure of the float 5 does not affect this pressure difference. Therefore, the blockage becomes rough. Since the ball valve 3a must be located at the center of the port of the valve seat 3b, the impact of the closing operation causes eccentric wear on the opening edge of the valve seat.
The airtightness of the valve is impaired.

In order to automatically center the ball valve 3a on the valve seat 3b, the ball valve 3a must be guided with play in the lever arm 5b, i.e. the ball valve must necessarily be eccentrically guided on the valve seat. will be done.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to reduce the cost by approximately one-tenth that of conventional valves.
The object of the present invention is to provide a separation valve that requires less than 0.3 kg/h of steam loss.

<Means for Solving the Problems> In order to achieve the above object, the present invention provides a valve seat fixed to the wall of a chamber for accommodating a liquid phase and having a port communicating with a discharge passage, and a guide means. a valve body displaceable between a closed position and an open position along a passageway defined by the valve body and engaging the port in the closed position, and controlling opening of the valve body in response to a liquid phase water level in the chamber; means for discharging a liquid phase from a two-phase fluid under pressure, the guide means comprising a tubular sleeve coaxial with the port and projecting from the flat surface of the valve seat, and the valve body disposed within the sleeve. It has a slidable body and a truncated conical needle protruding from the center of a flat plate facing the flat surface of the valve seat. The annular space communicates with the chamber through a plurality of passages, the passages being inclined with respect to the flat surface of the valve seat, and the inner end of the passage communicating with the chamber through a plurality of passages. It is characterized by being opened at the outer periphery of the annular space in a state facing the plate.

With this configuration, the valve body can be reliably engaged with the center of the port by guiding the valve body along the inside of the sleeve of the valve seat. Furthermore, the conical shape of the needle reduces the impact when it engages and closes the port. Further, the force with which the needle moves during occlusion is attenuated by the arrangement of the annular space and the passage communicating it with the chamber. That is, condensate flows at a considerable speed along the valve seat surface, is deflected by the flat plate of the body, and then discharged along the needle. A dynamic pressure is thus created on the plate acting in the opposite direction to that pressure.

Furthermore, when the needle moves toward the valve seat and closes, dynamic pressure of condensate flowing out between the needle and the valve seat port acts, so that the needle can be more reliably engaged with the center of the port.

Preferably, the cam at the tip of the second arm of the float lever engages with the neck of the valve body with play so that the valve body can move relative to the valve body in the axial direction.

With this configuration, the valve body can be made relatively unaffected by the float, especially when displacement of the float causes rocking during valve opening/closing operations. Furthermore, the water level difference corresponding to the closed and open positions of the valve increases. Furthermore, when the valve is closed, movement of the valve body is not restricted until the needle is press-fitted into the opening by the action of the cam.

Preferably this play is between 0.1 and 0.8 mm.

In a preferred embodiment, this play is adjustable, in particular by screw means held in the extension of the first arm of the lever, which screw means press approximately axially against the center of the rear part of the valve body upon closure. do.

Other objects and advantages of the invention will become apparent from the following description of embodiments, taken in conjunction with the accompanying drawings.

<<Embodiment>> In the first embodiment of the present invention shown in FIGS. 2a and 2b, the valve 13 has a reciprocating valve body 13a and a valve seat 1.
Consists of 3b. In the flat surface 24 of the valve seat 13b,
A cylindrical port 21 with a tapered portion 23 that expands toward the valve body 13a is precisely formed. The valve seat expands behind the port 21 and becomes the feed pipe 22,
This feed tube 22 is formed in the center of the threaded insert 22a. As shown more clearly in FIG. 3a, the valve seat is fixed to the wall of the separation chamber by means of this threaded insert 22a.

The valve body 13a slides within a cylindrical sleeve 26 protruding from the flat surface 24. This sleeve 26 is divided longitudinally by slots 27.
A second lever arm 15b is housed in the slot 27 and slides about a laterally extending shaft 15c. A first lever arm extends perpendicularly to the second lever arm 15b, and a float 15 is disposed at the tip thereof (see FIG. 3a).

The valve body 13a has a body portion 30 that reciprocates within the sleeve 26. A plate 31 is formed at the tip of the body 30, and a truncated conical needle 32 protruding from the center of the plate 31 is connected to the valve seat port 2.
It is complementary to the taper portion 23 of No. 1.

The needle 32 is coated with a layer of stellite, and the tapered portion 23 is formed by grinding against the needle 32. The body 30 has a concave neck 33, which is surrounded on both sides by flat surfaces 34,35. As shown in FIG. 2a, the tip of the second lever arm is a round cam with a flat surface 34,
35, thereby causing the lever 15 to
The valve body 13a is adapted to be displaced within the sleeve as the valve body 15a swings about the shaft 15c.

The amount of rearward movement of the valve body 13a is limited by contact with a split ring 36 accommodated in a groove in the sleeve 26. When assembling the valve,
This ring 36 is placed in a predetermined position after the valve body 13a is inserted into the sleeve 26.

As shown in Figures 2a and 2b, between the rings
40 are the flat surface 24 of the valve seat, the inner wall of the sleeve 26, the front plate 31 of the body 30, and the needle 3.
2. This annular space 40 communicates with the separation chamber 10 via three passages (see FIG. 3a). The first passage 27b is an extension of the slot 27 to the flat surface 24 of the valve seat, and the end thereof forms a groove 27a having an arcuate cross section in the valve seat.
Two transverse passages 25', 25'' are bored perpendicularly to the axis of the sleeve 26. The axes of these passages are horizontally colinear and intersect the axis of the sleeve 26, and the valve seat is flat. These passages 25', 25'' extend slightly beyond the cylindrical inner surface of the sleeve 26 and terminate in a conical shape, with each cone having a tapered apex. Part 23
located opposite to the outside.

Between the exits of the passages 27b, 25', 25'' and the annular space =4
0 in this manner, the flow is made to enter the annular space 40 obliquely with respect to the radial direction, and flow in the direction of the plate 31 of the valve body 13a.

The description will now be made with reference to FIGS. 3a and 3b, in which only an outline of the structure of the valve 13 is shown, since the scale is larger than in FIG. 2. The separation chamber 10 has a pear shape and is attached to a flange stand 45. The flange stand 45 has a lateral flange 46,
47, which are connected to the discharge channel via the channel 14 and to the drain bottle via the channel 12, respectively.

In addition to the valve 13 operated by the float 15, a thermostatic valve 16 is mounted on the flange base 45. Similar to the conventional configuration of FIG.
0 and is normally immersed in condensate, while a thermostatic valve 16 is located in the upper part of the chamber 10 and discharges non-condensables via channel 14 to a discharge channel. It's becoming like that.

The configuration in which the opening operation of the valve 13 is controlled by the float 15 is almost the same as that shown in FIG. However, the opening amplitude is
b), the flow rate of condensate is restricted not only by the restriction between the needle 32 and the valve seat 13b, but also by the passages 27b, 25', 2 at the upstream point.
A similar limitation is imposed by the diaphragm of 5".

The flow caused by these passages enters obliquely as described above, so that the flow caused by the plate 31 and the needle 3
After being deflected by 2, it flows into port 21. The reaction resulting from this deflection counteracts the pressing force on the rear face of the barrel 30 resulting from the pressure in the chamber 10. Therefore, the blockage of valve 13 is not as severe as in the separator of FIG.

Furthermore, when the valve body 13a reciprocates within the sleeve 26, there is very little radial play, and the mutual alignment of the tapered portion 23 and the needle 32 is ensured by the above-described grinding. This is because this grinding is carried out guided in the same manner as when the valve is slid closed.

Furthermore, the radial reactions on the valve body 13a caused by the flows flowing in from the passages 25' and 25'' cancel each other out, while the vertical reactions caused by the flows flowing in from the passage 27b cancel each other out on the second lever arm 15b.
This corrects the tendency for the fitting of the valve body 13a to wobble, which is derived from the fact that the head of the valve body 13a acts on the neck portion 33 at a position spaced apart from the center of the surface 35.

All configurations of the valve according to the invention are thus such that the relative position of the valve body with respect to the valve seat is always reproduced identically when the valve is closed.

Tests of the prototype showed that the steam loss was lower than the expected limit of 0.3 kg/h at 20 bar and a saturation temperature of 215°C.

In the second embodiment of the invention shown in FIGS. 4 and 5, the second lever arm 15b engages with the neck 33 between the palm faces 34, 35 with considerable play to form a cam; is approximately half the distance that the valve body 13a reciprocates between the illustrated closed position and the fully open position where the body 30 abuts the elastic ring 36.

First lever arm 15a connected to the float
is a portion 1 extending downward beyond the axis of the valve body 13a.
It has 5d. This extension 15d has an internal threaded hole into which an adjusting screw 38 with a locking nut 39 is screwed. This screw hole is inserted into the valve body 13a when the needle 32 is in close contact with the valve seat.
It is coaxial with The front portion 38a of the screw 38 is rounded and abuts against the rear plate of the valve body 30.

As shown in FIG. 5, when the valve body 13a is in the closed position and the rear part of the second arm 15b is still in contact with the rear surface 35 of the neck part 33, the front part 38a of the screw and the valve body body are in contact with each other. There is play j in between. This play j is caused by the above-mentioned second arm 15b and neck portion 33.
This can be adjusted by rotating the screw 38.

In reality, the play j is the total reciprocating distance of the valve body 1 to 2
It is about 0.1 to 0.8 mm. Due to this play, in the closing operation, after the front part 38a of the screw 38 comes into contact with the rear surface 30 of the valve body, the second lever arm 15
b will engage the front surface 34 of the neck 33.
The valve body 13a is attached to the valve body body by a screw 38.
It is held in the closed position by the pressing force of.

The play j does not participate in the opening operation of the valve 13. This is because the float 15 engages the rear part of the second lever arm 15b (cam) with the rear surface 35 of the neck part 33 due to the buoyancy of the condensed water in the chamber 10, and pushes the valve body 13a against the pressure in the chamber 10. When opening, screw 38
This is because the front portion 38a is already reliably separated from the rear surface 30 of the valve body.

When the valve 13 begins to open, the condensate passes through the passageway to the front plate 31 of the valve body and the tapered needle 32.
Because the condensate flows into the valve seat port 21 after being deflected by the condensate, a reaction force is generated on the front plate 31 to offset a portion of the pressure of the condensate acting on the rear plate of the body 30. Therefore, the float 15 starts floating on the surface of the condensate again, while the second lever arm 1
5b moves the valve body 13a to the fully open position with less force through engagement with the rear surface 35 of the neck portion 33.

As the condensate flows out through the flow path 14, the float 15 descends in the chamber 10, but at this time, the valve body 13a is moved by the static pressure of the condensate acting on the rear plate of the body 30 and the condensate jet. Due to the interaction between the dynamic pressure acting on the front surface 31 and the tapered needle 32 and the restraining force of the second lever arm 15b acting on the rear surface 35 of the valve body neck 33, it moves forward and closes the valve.
In this state, even if the float 15 vibrates on the surface of the condensate, there is play between the neck 33 and the second lever arm 15b, so the valve seat 13 of the valve body 13a
Movement in direction b is unaffected.

Furthermore, if the pressure in the steam piping network decreases with the separator closed, at least a portion of the condensate in chamber 10 may evaporate and the water level may drop below the isolation valve. In general, it is more difficult to make valves and fittings gas-tight than liquid-tight. However, in the separator of this embodiment, when the water level of the condensate drops below the position of the valve 13, the weight of the float 15 applied to the tip of the first lever arm 15a causes the rear plate of the valve body 30 to axially Since the pressing force applied to the tip of the screw 38 increases, the airtightness between the needle 32 and the valve seat 13b can be completely maintained.

Although the present invention has been described above with reference to its preferred embodiments, the present invention is not limited thereto and can be modified in various ways.

In particular, in the above embodiments, the valve has been described with respect to a closed float type separator, but it can also be applied to a so-called open float type separator. This type of separator has a bell-shaped float with a small vent at the top.
The drain bottle communicates directly below the bell-shaped float. As long as steam enters from the lower part of the bell-shaped float, the float floats on the condensate and closes the valve under the action of the lever. If condensate flows in,
The float descends, allowing steam to escape through the vent, opening the valve. When the condensate stops flowing out, the steam rises again in the float and closes the valve.

The valve of the invention can also be used in water and oil separators, etc. in compressed air generators.

Furthermore, in the embodiments of FIGS. 4 and 5, it is also possible to replace the screw 38 with a non-adjustable member if precision machining is possible.

<<Effects of the Invention>> As described above, in the separator valve according to the present invention, a truncated conical needle is provided on the valve body that slides within the sleeve coaxial with the valve seat port, and the needle is used to control the port. Since it was made to open and close, when it is blocked,
It is possible to avoid the drawbacks of the conventional valve body, such as the valve body fitting off the center of the valve seat due to the swinging of the float, etc., and as a result, the valve wears out and loses its sealing performance.

Further, the valve body cooperates with the sleeve and the valve seat to define an annular space, which communicates with a chamber for accommodating a liquid phase via a plurality of passages, and the passages are connected to the valve seat. The inner end of the passage is opened at the outer periphery of the annular space, facing the plate of the valve body, so that condensate flows along the passage. After being deflected by the plate of the valve body, it is discharged along the needle. In this way, dynamic pressure is generated on the plate that acts in the opposite direction to that pressure, so the impact of the valve body when it is closed can be attenuated by the action of the inflowing condensate, further ensuring prevention of valve wear. It can be made into something.

Furthermore, when the needle moves toward the valve seat and closes, dynamic pressure of condensate flowing out between the needle and the valve seat port acts, so that the needle can be more reliably engaged with the center of the port.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of a conventional sealed float type separator, FIG. 2a is a vertical sectional view of a separation valve according to a first embodiment of the present invention, and FIG. 2b is a cross-sectional view of the separation valve taken in the horizontal direction. 3a is a longitudinal sectional view of a separator equipped with the separation valve, FIG. 3b is a partially cutaway plan view of the separator, and FIG. 4 is a separator equipped with the separation valve according to the second embodiment of the present invention. FIG. 5 is a longitudinal sectional view of the separation valve of FIG. 4. 10... Chamber, 13a... Valve body, 13b... Valve seat, 14... Discharge path, 15... Float, 15a
...First arm, 15b...Second arm, 15d
... extension part, 21 ... port, 24 ... flat surface,
25', 25''...passage (hole), 26...sleeve,
27... Slot, 27a, 27b... Passage (slot extension), 30... Body, 31... Plate, 32... Needle, 33... Neck, 38...
Screw, 40...between rings.

Claims (1)

[Scope of Claims] 1. A valve seat fixed to the wall of a chamber for containing a liquid phase and having a port communicating with a discharge passage, and a valve seat that is arranged in a closed position and an open position along a passage defined by a guide means. a two-phase fluid under pressure, comprising a valve body displaceable between and engaging the port in the closed position, and means for controlling opening of the valve body in response to a liquid phase level in the chamber. In an isolation valve for discharging a liquid phase from a valve, the guide means comprises a tubular sleeve coaxial with the port and projecting from a flat surface of the valve seat;
The valve body has a body slidable within the sleeve and a truncated conical needle protruding from the center of a flat plate facing the flat surface of the valve seat. The sleeve and the valve seat cooperate to define an annular space, the annular space communicating with the chamber via a plurality of passages, the passages being inclined with respect to the flat surface of the valve seat. A separation valve for discharging a liquid phase from a two-phase fluid, characterized in that the inner end of the passage is opened at the outer periphery of the annular gap while facing the plate of the valve body. . 2. The separation valve for discharging a liquid phase from a two-phase fluid according to claim 1, wherein the sleeve has a rear abutment member that limits the open position of the valve body. 3. said means responsive to the liquid phase level comprising a closed float disposed at the end of a first arm of a lever, said second arm being formed in said sleeve in a plane passing through its axis; Claim 1 further comprising a cam extending into a longitudinal slot and engaging an annular neck of said barrel.
Separation valve for discharging a liquid phase from a two-phase fluid as described in paragraphs. 4. The plurality of passages are arranged diametrically opposite an extension of the longitudinal slot so as to be tangential to the flat surface of the valve seat on an axis perpendicular to the plane of the slot. from the two-phase fluid according to claim 3, wherein the hole extends inward from the outside of the sleeve and terminates at a position slightly spaced apart from the port. Isolation valve for draining the liquid phase. 5. The cam forming the tip of the second arm,
The liquid phase from the two-phase fluid according to claim 3 is engaged with a neck formed in the body of the valve body while giving the valve body play in its axial direction. Isolation valve for discharging. 6. Separation valve for discharging a liquid phase from a two-phase fluid according to claim 5, characterized in that the play is 0.1 to 0.8 mm. 7. Separation valve for discharging liquid phase from a two-phase fluid according to claim 5, characterized in that the lever of the float has means for adjusting the play. 8. Said means for adjusting said play comprises a screw engaging an extension of said lever and disposed substantially on said axis of said valve body, one end of said screw being connected to said rear part of said valve body upon actuation. 8. A separation valve for discharging a liquid phase from a two-phase fluid according to claim 7, characterized in that it abuts approximately at the center of the valve. 9. A closed float separator, characterized in that the axis of the port is horizontal, and the position of the valve seat in the chamber is below the water level at which the float starts to operate and open the valve body. A separation valve for discharging a liquid phase from a two-phase fluid according to claim 3 for use in. 10. Separation valve for discharging a liquid phase from a two-phase fluid according to claim 1, characterized in that the needle is coated with stellite. 11. A separation valve for discharging a liquid phase from a two-phase fluid according to claim 1, characterized in that the needle and the port are fitted by grinding together.