RU2535523C1 - Gas pressure control valve - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: plunger is provided as a control valve with the effective area of the plunger being equal to the area of a throttling seat, in order to improve operation precision of the valve operated in the wide flow rate range. The plunger is coupled with a setting spring and a damper by a locking ring that provides for improved reliability of interaction of movable control valve parts at abrupt change of input pressure and at vibration loads. The plunger is fitted by a channel I communicating the cavity of controlled pressure E with the sealing cavity K to reduce the deformation of sealing rings. The damper set inside the setting spring beyond the gas flow does not create gas flow disturbances at the inlet to the control valve.

EFFECT: higher stability and precision of control valve operation in wide range of gas flow rates.

1 dwg

Description

The invention relates to automatic devices for regulating gas pressure and can be used in power engineering.

A gas pressure reducer is known (see USSR author's certificate No. 855525 of 08/15/81, G05D 16/10), comprising a pressure reducing valve with a seat, a piston rod and a sensing element in the form of a piston connected by a spring to the adjusting screw.

In the indicated reducer, the presence of unbalanced force from the variable inlet pressure acting on the valve, at high gas flow rates, reduces the accuracy of maintaining the controlled pressure, and the organization of throttling of the gas flow inside the sensing element limits the possibility of reducing the dimensions of the structure. In addition, the design does not provide for a regulated damper to eliminate self-oscillations, the possibility of which is due to the presence of a reducing valve. Such a gearbox does not have high reliability, because one of the movable seals is under full inlet pressure.

Also known is a gas pressure reducer adopted as a prototype of the invention, comprising a spring-loaded valve, a sensing element in the form of a piston and, on the side of the inlet cavity, a pneumatic damper for eliminating self-oscillations (see USSR author's certificate No. 678466 of 05.08.79, G05D 16/10 ) Such a damper must have a high damping margin for efficient operation in conditions of variable gas inlet pressures. In addition, it introduces its own perturbation into the gas flow, which worsens the flow conditions around the pressure reducing valve.

The limitation of the use of this gearbox also includes the presence of an unbalanced variable force from the inlet pressure acting on the valve, which reduces the accuracy of the gearbox with a high gas flow rate. The necessary accuracy is achieved by increasing the area of the sensitive element, dimensions and weight of the structure.

The present invention is aimed at improving the stability, stability and accuracy of gearboxes operating in a wide range of gas flow rates.

To do this, in the proposed gearbox as a reducing valve, the plunger itself is made directly, the effective area of which is equal to the area of the saddle. The plunger is connected to the master spring and damper by means of a locking ring, which allows the plunger to be moved together with the spring. A channel is made in the plunger, which communicates a controlled pressure cavity with a collector of the plunger sealing cavity, which allows to reduce the pressure drop across each seal. The damper, made in the form of a friction pair "collet-holder", is installed inside the master spring, outside the gas stream.

The attached drawing shows a diagram of the proposed gearbox.

The gearbox contains the following basic elements:

- housing 1 with tips A and B for the supply and removal of gas;

- reducing plunger 2, the output end In which perceives the action of the control pressure;

- adjusting pressure adjuster in the form of a power master spring 3;

- a mechanical damper in the form of a friction pair “fluoroplastic collet 4 - ferrule 5” provides dynamic stability of the moving system during operation;

- a plate 6 with a sealed sleeve 7, based on the retaining ring 8, provide a continuous connection of the plunger 2 with the master spring 3;

- adjusting screw 9;

- O-rings 10, 11.

The cavity K between the sealing rings 10 and 11 is connected by a channel And in the plunger with a cavity of adjustable pressure E.

When the gearbox is operating, high-pressure gas enters the gearbox tip A, passes into the cavity G, from where it passes through the throttling gap formed between the edge of the seat D and the conical surface Ж of the plunger 2, into the cavity E, where it acts on the sensing element - the plunger 2 and is discharged to to the consumer through the tip B.

The pressure in the cavity E is a controlled pressure and is automatically maintained equal to the setting pressure, which is determined by the tightening force of the spring 3 using screw 9.

When the adjustable pressure does not match the pressure of the gear setting on the plunger 2, forces arise that move it, changing the area of the throttle slit of the gear in the right direction. In this case, the adjustable pressure also changes in the direction of decreasing the mismatch with the setting pressure.

In the proposed gearbox, the movable system is unloaded from the action of the variable unbalanced force of the inlet pressure due to the equality of the effective area of the sensitive element - the plunger and the area of the throttle seat, which allows to increase the accuracy of the gearboxes operating in a wide range of flow rates.

The joint movement of the plunger with the set spring and damper increases the reliability of the gearbox during gas flow disturbances and vibration loads, and the communication of the adjustable pressure cavity with the collector of the sealing cavity of the plunger reduces the pressure drop across each sealing ring, which increases the reliability of the gearbox at high inlet pressures.

The damper installed inside the driving spring outside the gas flow does not create disturbances in the gas flow at the inlet to the gear during operation.

Claims (1)

A gas pressure reducer comprising a housing with inlet and outlet cavities, a pressure reducing valve with a seat, a rod, a plunger-type sensitive element coupled by means of a control spring with an adjusting screw, and a damper, characterized in that the plunger itself is made as a pressure reducing valve, effective area which is equal to the area of the throttle seat, the plunger is connected to the master spring and damper using a locking ring, and a channel is made in the plunger that communicates a controlled pressure cavity with a the trajectory of the plunger sealing the cavity; a damper is installed inside the master spring, made in the form of a friction pair "collet-holder".