JPH0481674B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is a float valve that uses the difference in specific gravity between gas and liquid to open and close the valve port with a float, and automatically discharges one fluid from an airtight mixing system. Regarding.

The above float valve is a steam trap that automatically discharges condensate generated in a steam piping system, an air trap that automatically discharges condensed water generated in a compressed air piping system, and an air trap that automatically discharges air mixed in a water piping system. This is an air vent etc. that discharges the air.

The gas with lower specific gravity is located above the liquid with higher specific gravity, and moves up and down according to changes in the quantitative ratio between the liquid level and the gas. The float floats on the liquid surface due to the balance between the buoyant force acting on it and its own weight, and moves up and down with the liquid surface. Float valves take advantage of these natural laws. Gas and liquid are separated in a valve chamber, a valve port is placed at the top or bottom of the valve chamber, and the valve port is opened by the vertical movement of a float housed in the valve chamber. It opens and closes to selectively and automatically discharge one fluid.

<Prior Art> Conventionally, there is a float type trap, for example, as a float valve. This opens the valve port at the bottom of the valve chamber,
This valve port is opened and closed directly on the surface of a float placed freely within the valve chamber to discharge condensate that accumulates at the bottom of the valve chamber. This trap opens and closes one valve port with one float, which has a limit on the area of the valve port and is not suitable for discharging a large amount of condensate.

Patent No. 118910 has a trap that solves this problem. The first valve opening is opened at a lower position in the valve chamber, the second valve opening is opened at a higher position than the first valve opening, and the valve is placed inside the valve chamber and rises and falls according to the liquid level in the valve chamber. A valve body is provided that directly opens and closes the first valve port and opens and closes the second valve port on the surface of the float, one end of which is connected to the valve body to operate the valve body, and the other end extends above the float. It consists of a lever that is provided so that the float comes into contact with it after opening the valve port.

<Problem to be solved by the present invention> However, in the trap described above, when the amount of condensate discharged is small or medium, the float discharges the condensate only by opening and closing the first valve port, while the second valve The port is always closed in a gas atmosphere, and the second valve port and the valve body cannot perform a water-sealing function, leading to fluid leakage. If this is a trap for steam, the valve seat forming the valve port and the corresponding float are made of metal, so the sealing performance will be even worse. In the trap described above, a coil spring is provided to close the valve body that opens and closes the second valve port in order to prevent leakage, and there is a drawback that the number of parts increases. In other words, the float of the trap operates to open the second valve port, but has no involvement in closing the second valve port.

Furthermore, since the float itself is not guided by anything when it opens the first valve port, its sealing performance becomes unstable, leading to fluid leakage.

Therefore, a technical object of the present invention is to provide a float valve which is a mechanism having a sub-valve, has a simple structure, and has an excellent valve structure when both valve seats are closed.

<Means for Solving the Problems> The technical means of the present invention taken to solve the above-mentioned technical problems is to form an inlet and an outlet in a valve casing having a valve chamber, and to install a valve at a low position in the valve chamber. A first valve port and a second valve port that communicate with the chamber and the outlet are opened, and a float is housed in a free state in the valve chamber to directly open and close the first valve port by floating up and down according to the liquid level in the valve chamber, A lever equipped with a valve body for opening and closing the second valve port is pivotally connected in the valve chamber, and one end of the lever has a float attached to the first valve.
The lever is formed such that it comes into contact with the second valve port after opening the valve port and opens the second valve port, while the other end of the lever is configured such that the float is completely seated in the valve port when the first valve port is opened. It is formed as a float seat to guide the float.

<Effect> The operation of the above technical means is as follows.

The float accommodated in the valve chamber in a free state is vertically displaced along with the liquid level within the valve chamber. When the inflow flow rate is large, the float opens the first valve port and the second valve port via the lever to discharge the fluid. When the flow rate decreases and the liquid level drops, the float no longer engages with the lever, the second valve port closes, and only the first valve port opens and closes. When the liquid level drops and the float closes the first valve port, the second valve port is always below the liquid level and is sealed with water, so that the sealing performance is good and fluid leakage is prevented. Further, the float that has descended at this time is guided by coming into contact with the other end of the lever, and is completely seated in the first valve port to close it. On the other hand, since the weight of the float acts on the other end of the lever, the second valve opening can obtain a larger closing force.

<Example> An example showing a specific example of the above technical means will be described. (See Figures 1 and 2) This embodiment is applied to a closed float type steam trap. A lid 4 is fastened to the main body 2 with bolts (not shown) to form a valve casing having a valve chamber 6 therein. A gasket 8 is interposed between the main body 2 and the lid 4 to keep them airtight. An inlet 10 is formed in the upper part of the lid 4, and an outlet 12 is formed in the lower part.
The inlet 10 communicates with the upper part of the valve chamber 6, is connected to steam-using equipment (not shown), etc., and introduces condensate into the valve chamber 6. A first valve seat 16 having a first valve opening 14 is screwed to the lower part of the main body 2, and a second valve seat 20 having a second valve opening 18 to the lower part of the lid 4. The first valve port 14 communicates with the valve chamber 6 and the outlet 12 via a communication passage 22 formed in the lower part of the main body 2, and the second valve port 18
directly communicates the valve chamber 6 with the outlet 12 and leads the condensate in the valve chamber 6 to the outlet 12. The inlet 10 and the outlet 12 open horizontally and each form an internal thread for piping. Gaskets 16a, 20a maintain airtightness between each valve seat 16, 20 and the corresponding member.

A hollow spherical float 24 made of a thin stainless steel plate is accommodated in the valve chamber 6 in a free state. float 2
4 floats on the condensate accumulated in the valve chamber 6 and rises and falls with the liquid level.

A lever attachment member (not shown) is attached to the lid 4 with a pin, and the lever 28 is attached to the lever attachment member with a pin 30. Therefore, the lever 28 is connected to the pin 3
It can rotate using 0 as the fulcrum. Lever 28 is pin 3
0 as a fulcrum, an arm portion 28a is formed at the upper part, and a float seat 28b is formed at the lower part. The arm portion 28a of the lever 28 extends diagonally above the float 24 at an angle α from the vertical line. Float seat 28b at the bottom of the lever 28 Valve body 32 that opens and closes the second valve port 18
Attach. Float seat 2 at the bottom of the lever 28
8b is the central axis 1 of the first valve port 14 on the bottom surface of the valve chamber 6.
4a and the central axis 1 of the first valve port 14.
Two stripes are formed on a cylindrical surface having a radius having the same length as the radius of the float 24, with 4a being coaxial.

The second valve seat 20 is installed at a position lower than the liquid level at which the float 24 completely closes the first valve port 14 in contact with the valve seat 16 and the float seat 28b when the liquid level in the valve chamber 6 decreases. Reference number 34 is a rib that guides the float 24 in the vertical direction, and is formed at two locations in total, one on the front side of the page, and a slight gap is formed between it and the float 24. Further, a rib 35 is formed on the opposite wall in the valve chamber 6 facing the lever 28a.

Attach the bimetal 36 to the lid 4 with screws 38. The bimetal 36 is approximately U-shaped and expands when the temperature is low, exerting a force that pushes up the lever 28b to open the second valve port 18, and contracts when the temperature is high, causing the lever 2 to open.
It returns to a shape that does not involve 8b.

The operation of the steam trap is as follows. The inlet 10 is connected to a location where condensate is generated, such as steam-using equipment. Condensate and steam flow into the valve chamber 6, where the condensate is separated from the lower part and the steam is collected at the upper part. When the amount of condensate flowing in is small, the floating of the float 24 is also small and only the first valve port 14 is opened and closed, and the condensate flows out to the outlet 12 through the first valve port 14 and the communication path 22. When the amount of water condensed into the valve chamber 6 increases, the float 24 rises as the liquid level rises, and comes into contact with the arm portion 28a of the lever 28 and the rib 35 on the opposite wall. When the liquid level further rises, the buoyancy of the float acts as a wedge force on the arm portion 28.
It acts on a. This wedge force causes the lever 28
rotates in the valve opening direction (clockwise in FIG. 1), and the valve body 32 opens the second valve port 18. The condensate in the valve chamber 6 is discharged from the first valve port 14 and at the same time
It is discharged from the valve port 18 to the outlet 12.

When the liquid level drops due to discharge, the float 24 also descends, and as the float descends, the lever 28 rotates in the valve-closing direction (counterclockwise in FIG. 1) and closes the valve body 32.
closes the second valve port 18 and stops the condensate from flowing out from the second valve port 18. At this time, the valve body 32 is closed by the force due to the pressure difference between the primary pressure in the valve chamber 6 and the secondary pressure at the outlet 12.

If the liquid level in the valve chamber further decreases, the float 24
is lowered to open the first valve port 1 as shown in FIG.
4 is also closed to completely stop the flow of condensate. At this time, the float seat 28b of the lever 28 is parallel to the central axis of the first valve port, is coaxial with the central axis of the first valve port, and is located on a cylindrical surface having a radius of the same small length as the float. Since the float 24 is formed in a strip, the lowered float 24 contacts the float seat 28b and at the same time seats on the first valve seat 16, completely closing the first valve port 14. Furthermore, at this time, since the weight of the float 24 acts on the float seat 28b, the force causes the valve body 32 to move to the second position.
It acts as a force that presses the valve port 18, increasing the valve closing force.

Further, as shown in FIG.
Since the valve port 18 is located at a position lower than the liquid level 40 when the float 24 completely closes the first valve port 14, it is constantly submerged in water and its water sealing action protects the valve body 32 and the second valve seat 20. This improves the sealing performance and prevents leakage of condensate and steam.

<Effects of the invention> The present invention produces the following unique effects.

Since a sub-valve is used, the amount of condensate discharged is increased, and since the second valve port is always submerged in water, its water-sealing effect greatly improves the sealing performance between the valve body and the valve seat. Furthermore, since the lever and the float seat are shared, the sealing performance of both the first valve port and the second valve port can be improved.

Further, unlike the conventional method, a coil spring for closing the second valve port is not required, and the structure is simple and the number of parts is reduced.

In addition, the condensate discharged from the first valve port causes the second
Since the pressure on the secondary side of the valve port increases, the pressure difference acting on the second valve port becomes smaller. Therefore, the second valve port can be opened and closed with a small operating force, or the valve port can be designed to be larger accordingly, so that the discharge flow rate can be further increased.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a sealed float type steam trap according to an embodiment of the float valve of the present invention, and FIG. 2 is a partial plan sectional view of the first valve seat portion of FIG. 1. 2...Main body, 4...Lid, 6...Valve chamber, 10...
Inlet, 12... Outlet, 14... First valve port, 18...
...Second valve port, 24...Float, 28...Lever, 28a...Arm portion, 28b...Float seat.

Claims (1)

[Claims] 1 An inlet and an outlet are formed in a valve casing having a valve chamber, and a first
A valve that opens a valve port and a second valve port, and houses a float in a free state in the valve chamber that floats up and down according to the liquid level in the valve chamber to directly open and close the first valve port, and opens and closes the second valve port. A lever with a body attached thereto is pivotally coupled within the valve chamber, and one end of the lever is formed so as to abut after the float opens the first valve port to open the second valve port, while the other end of the lever is configured to contact the float to open the second valve port. The end of the float valve is formed as a float seat for guiding the float so that it is completely seated on the valve opening when the first valve opening is closed.