JPS6056956B2 - Float steam trap - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a float type steam trap, and particularly to a float type steam trap used in places where large back pressure acts and where this back pressure fluctuates, such as when recovering condensate. Regarding.

In a float type steam trap, the area of the valve hole that can be opened and closed varies depending on the pressure difference between the inlet side pressure and the pressure on the outlet side of the valve hole, that is, the back pressure.The larger the differential pressure, the larger the area of the valve hole that can be opened and closed. becomes smaller.

When installing this trap at a location where condensate collection is performed,
For operational safety, the valve hole area is set assuming a situation where no back pressure acts and the differential pressure between the valve and the inlet side is large, such as when starting a steam system. Therefore, although normally the differential pressure is small and the valve hole area is large and opening/closing is possible, the valve hole area is set to be small and the amount of discharge is small. In view of the above circumstances, the present invention maintains the differential pressure acting on the valve hole related to changes in the outlet side pressure, that is, the back pressure, to a small state below a predetermined value, opens and closes a large valve hole area, and generates a large amount of condensate. The aim is to create a float-type steam trap that can discharge . The technical means of the present invention taken to achieve the above object is to provide a condensate reservoir chamber whose inlet communicates with the outlet through a valve hole drilled in the valve seat, and a float disposed inside the condensate reservoir chamber. In a device that opens and closes a valve hole to discharge condensate by ascending and descending, a back pressure chamber is formed on the outlet side of the valve hole in continuity with the valve hole, and the outlet side opening of the back pressure chamber is throttled by a valve seat. A valve body is placed on the outlet side of the throttle valve seat, a piston with the same pressure receiving area as the throttle valve seat is connected to the valve body with a connecting rod, and the outlet side of the valve body and the side of the piston connected to the valve body are connected to the valve body. The other side of the piston closed with the plug that holds the valve seat is communicated with the inlet side or the condensate reservoir chamber through a pressure passage, and the valve body is closed using the elastic force of the bellows or other elastic means. It is biased in the valve opening direction.

The action is as follows. When the float is in the open state, the pressure on the inlet and outlet sides acts on the valve body and the piston, which have the same pressure receiving area, in opposite directions, so the valve body acts on the throttle valve due to the biasing force of the elastic means. away from the seat. When the float approaches the valve closing position, the amount of condensate flowing into the back pressure chamber from the valve hole decreases, so the pressure in the back pressure chamber decreases. When the pressure difference between the inlet side pressure and the back pressure chamber pressure reaches a pressure corresponding to the biasing force of the elastic means, the valve body seats on the throttle valve seat. When the float starts to open the valve, the float opens the valve hole using the differential pressure between the inlet side pressure acting on the area of the valve hole and the pressure inside the back pressure chamber. When the valve hole is opened, the pressure in the back pressure chamber increases, and the valve body moves away from the throttle valve seat against the inlet side pressure acting on the piston due to this pressure and the biasing force of the elastic means. Therefore, the valve body moves away from and seats on the throttle valve seat regardless of the outlet side pressure, and when seated, a pressure determined by the biasing force of the elastic means is created in the back pressure chamber.

The float opens and closes the valve hole based on the pressure difference between the back pressure chamber pressure and the inlet side pressure, so that the large valve hole can be opened and closed, and a large amount of condensate can be discharged. The present invention produces the following unique effects.

In the present invention, a member for adjusting the back pressure acting on a float such as a valve body is incorporated between the hole formed in the valve seat that communicates with the outlet and the plug, so the present invention is compact and the shape of the trap does not become large.

Next, the present invention will be explained in detail based on the embodiments shown in FIGS.

The trap housing is formed of a main body 1 and a lid 4 fixed to the main body 1 with bolts 3 through a gasket 2. The condensate reservoir chamber 5 is formed within the housing, an inlet 6 is opened at the upper part, and an outlet 7 is communicated with the lower part through an outlet passage 8 and a valve hole 9. The valve hole 9 is connected to the condensate reservoir chamber 5 side by a valve seat member 11 inserted into the lower part of the main body 1 via an O-ring 10. The opening end of the valve hole 9 on the reservoir chamber 5 side is limited by a valve seat 12 . The float 13 has a spherical shape and floats in the liquid in the condensate reservoir chamber 5, and directly opens and closes the valve hole 9 with its surface. 14 is a float seat that determines the lowering position of the float 13 and seats the float 13 on the valve seat 12.

A stepped portion is formed on the inner circumference of the valve seat member 11, and the inner circumferential end of this stepped portion becomes the throttle valve seat 15 against which the valve body of the back pressure regulating valve comes into contact. The back pressure chamber 16 is formed on the outlet side of the valve hole 9 in communication with the valve hole 9, and the outflow of fluid to the outlet side is regulated by the action of the back pressure regulating valve. The back pressure regulating valve 17 includes a valve body 18 corresponding to the throttle valve seat 15 from the outlet side, a pressure receiving part formed by a bellows 19, and a connecting rod 20 connecting the valve body 18 and the bellows 19.
The bellows 19 exerts an elastic force in a direction to move the valve body 18 away from the valve seat 15. The pressure receiving area of the valve body 18 and the pressure receiving area of the bellows 19 are formed to be the same. Bellows 1
A retaining plate 21 and a piston 22 are joined to both ends of the valve 9, and the retaining plate 21 is held between the valve seat member 11 and a plug 25 screwed into the valve seat member insertion opening 23 via a gasket 24. is connected to the connecting rod 20. Through hole 2
6 and the slit 27 provided in the holding plate 21 form a pressure guiding passage for introducing the inlet side pressure into the bellows outer circumferential chamber 28, and the back pressure regulating valve 17 adjusts the pressure in the outer circumferential chamber 28, the pressure in the back pressure chamber 16, and The back pressure chamber 16 is displaced due to the elastic force of the bellows 19.
The pressure is controlled as follows. Reference numeral 29 denotes an opening provided on the side of the valve seat member 11 to guide condensate to the outlet passage 8.

In addition, in the above configuration, the back pressure regulating valve 17 is connected to the float 1
Prior to closing the valve hole in step 3, the valve seats on the throttle valve seat 15 to cut off communication between the back pressure chamber 16 and the outlet side, thereby suppressing the pressure drop in the back pressure chamber 16 and maintaining the differential pressure below a predetermined level. However, if leakage occurs from the back pressure chamber 16 to the outlet side due to poor contact with the valve seat 15, etc., and the pressure inside the back pressure chamber 16 decreases significantly and the differential pressure cannot be maintained below a predetermined level, Alternatively, in case the volume of the back pressure chamber 16 is relatively large and the fluid (condensate and steam) in the back pressure chamber 16 condenses to cause a pressure drop and the differential pressure cannot be maintained below a predetermined level, the float 13 A configuration may be added in which a small amount of inlet fluid flows into the back pressure chamber 16 even when the valve hole 9 is closed. This configuration includes those in which the surface of the valve seat 12 is rough-finished or provided with slits, and those in which small holes are provided that communicate the back pressure chamber 16 with the inlet side. However, if the back pressure regulating valve 17 can completely cut off the communication between the back pressure chamber 16 and the outlet side, or if the pressure of the back pressure chamber 16 does not decrease when the valve is closed, the above configuration is unnecessary. The operation of the above embodiment will be explained.

When there is little or no inflow of condensate from the inlet 6, the float 13 descends and seats on the valve seat 12 as shown in FIG. At this time, the back pressure regulating valve 17 receives the inlet side pressure acting from the outer peripheral chamber 28, the pressure acting from the back pressure chamber 16, and the bellows 19.
The float 13 is seated on the throttle valve seat 15 before the valve hole is closed, cutting off communication between the back pressure chamber 16 and the outlet side, and reducing the inlet side pressure and the back pressure chamber. The pressure in the back pressure chamber 16 is controlled so that the pressure difference is below a predetermined value. Next, when the inflow of condensate from the inlet 6 increases, the float 13 floats up according to the liquid level in the condensate reservoir chamber 5 as shown in FIG. open. At this time, as mentioned above, the differential pressure is kept below a predetermined level, and this is not related to fluctuations in the outlet side pressure. The valve hole 9 can be opened and the discharge rate will be increased. Back pressure chamber 1 after opening the above valve
Since the pressure in the back pressure chamber 16 increases greatly and the differential pressure decreases, the valve body 18 of the back pressure regulating valve 17 is greatly retreated, and the condensate that has flowed into the back pressure chamber 16 flows to the outlet 7 without resistance. Next, entrance 6
When the inflow of condensate decreases or disappears, the liquid level in the condensate reservoir chamber 5 decreases as shown in FIG. 1, and the float 13 seats on the valve seat 12 and closes the valve hole 9. At this time, the back pressure control valve 17
In response to a decrease in the amount of condensate flowing into the back pressure chamber 16 from the valve hole 9, the amount of water flowing out from the back pressure chamber 16 to the outlet side is throttled.
The pressure drop in the float 6 is suppressed and the differential pressure acting on the valve hole 9 is kept below a predetermined level. Cut off communication to the exit side. The same action is repeated below. As described above, according to the present invention, the pressure in the back pressure chamber is adjusted by the action of the back pressure regulating valve so that the differential pressure between the inlet side and the outlet side of the valve hole is below a predetermined value,
The float can open and close the valve hole under a differential pressure below a specified level, and even when the differential pressure is large such as during startup, the float can open and close a large valve hole area, making it suitable for areas where back pressure fluctuates, such as areas where condensate recovery is performed. You can get a steam trap.

Further, although the above embodiments apply the present invention to a free float type steam trap, the present invention is not limited thereto, and can be applied to other float type steam traps, such as a lever float, a downward-facing or upward-facing bucket trap, etc. Even when applied to a float or the like, the same effects as described above can be achieved. In this embodiment, the pressure receiving part of the back pressure control valve is formed of a bellows, and the elastic force of the bellows itself is used to reduce the number of configurations. You may also use it.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a float type steam trap according to an embodiment of the present invention, and FIG. 2 is a sectional view showing the embodiment of FIG. 1 in another operating state. 5 is a condensate reservoir chamber, 6 is an inlet, 7 is an outlet, 9 is a valve hole, 11
1 is a valve seat member, 12 is a valve seat, 13 is a float, 16 is a back pressure chamber, and 17 is a back pressure regulating valve.

Claims (1)

[Claims] 1. A condensate reservoir chamber with an inlet communicating with the outlet through a valve hole drilled in the valve seat is provided, and condensate is discharged by opening and closing the valve hole by raising and lowering a float placed in the condensate reservoir chamber. , a back pressure chamber is formed on the outlet side of the valve hole in continuation with the valve hole, the outlet side opening of the back pressure chamber is formed by a throttle valve seat, a valve body is arranged on the outlet side of the throttle valve seat, and the throttle valve seat A piston with the same pressure receiving area as the valve seat is connected with a connecting rod, the outlet side of the valve body and the side of the piston connected to the valve body are communicated with the outlet, and the other side of the piston is closed with a plug that holds the valve seat. A float type steam trap in which the inlet side or condensate reservoir chamber is communicated through a pressure passage, and the valve body is biased in the valve opening direction using the elastic force of the bellows or other elastic means.