SUCTION VALVE

Abstract

A suction valve be placed in a pipe line and intended for flow material, by means of which the flow can be closed, regulated and back flow prevented, whereby the suction valve comprises a movable a locking means (3) placed in a valve house (1) and for it a counter face in the valve house and said locking means (3) can be moved by means of the pressure of the flow material by forming locking means (3) to be as piston parts or cylinder parts in the working cylinder The pressure of flow material necessary for moving locking means (3) is led into said locking means through an outlet valve (8,9, 10), which outlet valve is fitted inside the locking means (3).

Description

The invention relates to a suction valve to be placed in a pipe line and intended for flow material, by means of which the flow can be closed, regulated and back flow prevented, whereby the suction valve comprises a movable locking means placed in the valve house and for it a counter face in the valve house and said locking means can be moved by means of the pressure of the flow material by forming the locking means to be as piston parts or cylinder parts in the working cylinder. The valve is especially suited as a suction valve for screw and rotor compressors, which causes quite a small loss of flow and can be regulated and which closes as needed. By closing the suction valve the back flow from the compressor is prevented when the compressor stops.

Previously known is, among others, a suction valve from U.S. Pat. No. 6,695,007, where the flow of medium keeps the valve open. When the flow reduces, or for instance, while the suction effect of the compressor lessens, the spring in the valve pulls the closing means against the seat surface and closes the valve. In such a spring-return valve a little more pressure loss always builds up, because, by means of the flow, the valve-closing means is kept open. Pressure loss builds up even if the spring would be as to its counter force quite week. When rather big compressors are working almost day and night, so already the slight deterioration of the operating efficiency, because of their suction valve, becomes a remarkable expense in the production of compressed air. In addition, it is difficult to regulate a suction valve returning by spring force into intermediate position near the closing state in order to achieve the relief state of compressor. Thus the relief must be done in closing the valve, while the compressor is working, which takes place either in adding the spring back factor or otherwise moving the closing means against the closing surface.

In order to improve the presented disadvantages and to achieve by compressor use, as to its flow loss a very small suction valve, a new suction valve intended for flow material is developed, which can be placed in a pipe line and the closing means of which can be moved by means of the pressure of the flow material in forming the closing means to be as a piston or a cylinder part in a working cylinder which operates by means of the pressure of the flow material. The above presented invention is characterized in that necessary pressure of the flow material is led into said closing means through the outlet valve fitted inside the closing means.

The advantage of the invention is that the keeping of the valve open it does not cause any flow loss in the valve. The valve remains open both due to its mass by means of force of gravity and by means of the compressor's suction pressure, said pressure is allowed to impact in a cylinder space formed by closing means into a direction pulling the closing means into open position. The compressor must only one time suck the negative pressure through the outlet valve into said space, and afterwards no loss on keeping the valve open takes place. Control of the outlet valve fitted inside the closing means of the suction valve takes place with the pressure of medium led to it. Closing and opening of the suction valve is steered to take place by pressurized available medium. Thus control takes place in spite of the compressor running. When the closing valve is as to its inlet opening installed upwards, the closing means facilitates by means of its own mass the opening of the suction valve. The closing means can also be regulated to any intermediate place between close and open positions. By means of the outlet valve motions from closed state to open state of the closing means can be made quite fast, when the pressure of medium that presses the closing means to the closed position discharges fast through the outlet valve to the suction tube of the compressor. The suction valve causes very little pressure loss to the flow passing it, since it is possible to make the formatting of the income and exit sides very streamlined.

In the following the invention is disclosed with reference to the enclosed drawing, where

FIG. 1 shows a section view from the side of the valve open according to the invention.

FIG. 2 shows the valve in closed position,

FIG. 3 the valve connection diagrammatically.

FIG. 1 shows a suction valve, the outer casing of which is formed of two joined parts 1a and 1b, which can be attached to each other with bolts through holes 6. Connected to other part 1b, by means of wings 2 led across the circular flow channel, the fixed circular sleeve-like portion 4 of the closing means is fixed, the outer surface of which is fitted to work as a sliding surface together with part 3. Parts 3 and 4 are like a cylinder and a piston, which move in regard to each other. Part 3 is furnished with packing 11 and nestles in closing situation against the counter surface of part 1a, while packing 11 is compressing closing. A wing 2, which connects portion 4 to part 1b is a little thicker, whereby it is possible to lead through it a channel 5 from the outside into the part 4.

The outlet valve is fixed inside sleeve-like part 4 by threaded coupling 12. The outlet valve has a tap hole 7, which leads directly to the suction space of the compressor. Furthermore, it comprises in the cylindrical frame 8 of the valve moving a closing flange 10, which is of flexible material, as polyurethane. To the frame 8 a supporting flange 9 is connected. The closing flange 10 closes tap hole 7, if the pressure behind the closing flange 10, led along channel 5 and further along 13, is greater than the pressure in the tap hole 7. The pressure of the tap hole 7 dominates also inside closing means 3 and part 4 in the cylinder space. In the state described in the FIG. 1 no pressure is led through the channel 5 to the outlet valve. For instance, channel 5 can also be joined to same pressure with the compressor suction side, in other words to a chamber into which the tap hole 7 discharges. The closing means 3 stays in the state shown by FIG. 1 and does not try get closed. Thus the flow losses caused by the closing means are minimized.

The situation of FIG. 2 can be reached both on compressor stopping and working. For instance, from the compressor's pressure side control pressure is led behind the closing flange 10 of the outlet valve, whereby it moves to close the tap hole 7. The material of closing flange 10 gives in, so that pressure can get, by the way of the flexing outer edge of flange 10, into the cylinder space to circulate inside the closing means 3, and the pressure pushes the closing means 3 to closed position. Now the compressor runs relieved or it is stopped. The pressure cannot get discharged backward off the compressor.

If wanted to get the suction valve open, it happens very fast, since the control pressure of channel 5 is led out, which is a very small amount of air. Then in the cylinder space the pressure from the inside of the closing means 3 is at once able to push closing flange 10 of the closing means 3 a little to the left, whereby the pressure from the inside of the closing means 3 quickly discharges through the tap hole 7 into the suction space of the starting compressor and the closing flange 10 remains in the position shown by FIG. 1. Inside the closing means 3 negative pressure sucked by the compressor arises and the closing means 3 move quickly to open-position and the flow can pass the valve. So the running of the compressor or its starting accelerates the opening of valve. Further, the opening of valve is especially accelerated by the position of the suction valve, if it is according to the FIGS. 1 and 2, whereby the closing means 3 moves downward to open-position, assisted by force of gravity.

It is also possible to get for the closing means 3 adjusted intermediate positions in the position of the quick outlet valve according to FIG. 2 by leading through channel 5 only a regulated amount of medium into the space formed between the closing means 3 and the part 4.

FIG. 3 shows the main diagram of the valve. Valve 14 is a suction valve, comprising in FIGS. 1 and 2 parts 1a and 3. Valve 15 is an outlet valve comprising in FIGS. 1 and 2 parts 8, 9 and 10. Valve 16 is a control valve, by means of the opening of which the pressure is led to the outlet valve 15 and this causes that the suction valve 14 closes in spite of the running of compressor 12. The control pressure runs through the outlet valve into the closing means 3 and lifts up the closing means and the suction valve closes. When the pressure control of the valve 16 is removed, the low pressure or suction in the suction line 13 leading to the compressor, removes pressure from the inside of the closing means 3, and it gets down, which situation is the open position of the suction valve. The pressure line starting from compressor 12 has the reference number 17. The inlet opening of the suction valve in the diagram shown in FIG. 3 is described by the reference number 14. From compressor 13 pressure line 17 control pressure can be taken to the valve 16. It is also possible to take control pressure from some other outside pressure source.

Claims

1. A suction valve to be placed in a pipe line and intended for flow material, by means of which the flow can be closed, regulated and back flow prevented, whereby the suction valve comprises movable locking means (3) placed in a valve house (1) and for it a counter face in the valve house and said locking means (3) can be moved by means of the pressure of the flow material by forming locking means (3) to be as piston parts or cylinder parts in the working cylinder, characterized in that the pressure of flow material, necessary for moving locking means (3), is led into said locking means through an outlet valve (8, 9, 10), which outlet valve is fitted inside the locking means (3).

2. A suction valve according to claim 1, characterized in that by selected assembly position of the valve, force of gravity is utilized easing and accelerating the opening of the valve.

3. A suction valve according to claim 1, characterized in that the pressure of the steering flow material, led to the outlet valve, is fitted to close an outlet tap hole (7), for instance by means of closing flap (10) that moves by means of pressure, so that the closing means (3) would move into closing state by means of said flow material.

4. A suction valve according to claim 1, characterized in that reduction of the flow material pressure led to the outlet valve is fitted to open the tap hole (7) of outlet valve (8),(9),(10) for fast opening of the closing means (3).

5. A suction valve according to claim 1, characterized in that the tap hole of the outlet valve (8),(9),(10) is fitted to get open into the subsequent pipe line of the suction valve seen from the flow direction.

6. A suction valve according to claim 1, characterized in that the closing means (3) is a moving cylinder, which is fitted to move in regard to sleeve-like piston (4).

7. A suction valve according to claim 1, characterized in that the outlet valve (8),(9), (10) is fitted inside the sleeve-like piston (4).