RU2420681C1 - System for maintaining constant pressure in reservoir - Google Patents

Abstract

FIELD: machine building. ^ SUBSTANCE: system for maintaining constant pressure in reservoir consists of safety valve, of pump unit for filling reservoir with working medium, and of device of pneumatic setup of constant pressure in reservoir. The safety valve consists of a cylinder case. The case is assembled on a neck of the reservoir. Inside the case there is positioned an outlet valve with a shank end. The outlet valve is loaded with a tightening device. The device for pressure pneumatic setup is connected to the reservoir and to an above-the piston cavity by means of manipulators. The cavity is formed with the case of the safety valve and shank end of an inlet valve. The shank end corresponds to a piston and it seals the cavity. The system is equipped with a device unloading the outlet valve of its weight. The safety and the outlet valves are partially located in a chamber. The latter is assembled on the reservoir. ^ EFFECT: extended range of values of setup pressure in reservoir without additional adjustment of outlet valve operation; raised quality of maintaining constant pressure. ^ 5 cl, 1 dwg

Description

The invention relates to hydropneumatic automation systems and can be used to maintain constant pressure in reservoirs simulating the external environment when testing internal combustion engines, turbines, pulse devices in conditions of variable air or hydrostatic backpressure.

Known controlled safety valve for AS No. 528415 dated 09/15/1976, IPC F16K 17/02 with a spring-loaded shut-off element, discharge, control, damping and drain cavities, connected by channels in which chokes are installed, an adjustable pressure reducing valve and a controllable crane, and a damping cavity is connected in parallel with the choke with a drain cavity through a check valve with conductivity towards the drain cavity. When the controlled valve is opened, the drain cavity is unloaded from pressure, which ensures that the shut-off element operates in the mode of free bypass of the working fluid from the injection cavity into the drain cavity, as well as the inclusion of a damping cavity in the work, thereby reducing the discharge pressure drop.

The disadvantages of the analogue include the command (rather than automatic) activation of the safety valve and setting the latter only at a certain set pressure.

Known bypass valve for connection to the pressure line according to the patent of the Russian Federation No. 21393901 dated 07/27/1999, IPC F16K 17/06, designed to discharge part of the fluid flowing along the line when the fluid pressure exceeds the set pressure, and equipped with a spring-loaded shut-off element with the possibility of adjusting the opening opening valve.

The disadvantage of this bypass valve when installing it on the tank is the need for its long-term, requiring high professional training of the operator manual adjustment and adjustment at each targeted setting of the stationary working pressure in the tank.

The closest in technical essence to the claimed invention is the safety device for movable tanks adopted for the prototype according to the patent of the Russian Federation No. 2027095 of 01.20.1995, IPC F16K 17/02, including a housing with a valve seat and a cylindrical cup, which is coaxially mounted with the possibility of movement along the axis body spring-loaded exhaust valve with a shank associated with the cylindrical part of the glass. The discharge of the working fluid (product vapor in the tank) occurs when the load from the overpressure is exceeded by the setting force of the spring-pressing exhaust valve.

The disadvantages of the prototype are the adjustment of the valve to only one pressure value that exceeds the initial setting of the internal pressure in the tank and the need to reinstall the spring when changing the initial pressure setting in the tank in a wide range with a long and time-consuming adjustment of the sensitivity of the exhaust valve to exceed the set pressure.

The proposed system for maintaining a constant pressure in the tank solves the problem of significantly expanding the range of values of the set pressure in the tank with the exception of the need for additional adjustment of the exhaust valve and improving the quality of maintaining a constant pressure.

The essence of the invention lies in the fact that at any setting of the initial pressure in the tank, the exhaust valve is completely unloaded from external forces, and the force pressing it to the saddle is created by electromagnetic interference, which is removed at the time the equipment under test starts operating.

The technical result of the invention is achieved due to the fact that the system for maintaining constant pressure in the tank is equipped with a pump unit for filling the tank with a working medium, a pneumatic set point for the stationary pressure in the tank, connected via manipulators to the tank and to the over-piston cavity, which is formed by the valve body and the exhaust shank a valve made in the form of a piston, sealing this cavity, which is under pressure set point, and the device, unloading the exhaust valve from its weight, while the safety and exhaust valves are partially placed in the chamber mounted on the neck of the tank.

To increase the sensitivity of the operation of the exhaust valve, unloading from its weight is provided due to the installation of the device in the form of a support fixed in the neck of the reservoir with a threaded hole in the center and a spring, adjustable for installation effort.

The system for maintaining constant pressure in the tank 1 includes a safety valve 2, a cylindrical body 5 mounted on the neck 3 with a seat 4 using spacers, inside which the exhaust valve 6 with a shank made in the form of a piston 7 is over-piston, coaxially placed to move along the axis of the body a control cavity 8, supplemented by a cylinder 9 increasing its volume, a pressing device comprising a core 10, a coil 11, into the supply wire 12 of which a relay 13 is mounted, a pump unit 14 filling the tank 1 with a working fluid with a drain tank 15, a pneumatic device for setting the pressure in the tank 1 and the control cavity 8, consisting of a filling valve 16, a pressure gauge 17, an air pressure to hydrostatic converter 18 and manipulators 19 for connecting (disconnecting) the air to the control cavity 8 and 20 - to the tank 1, and the device for unloading the exhaust valve 6 from its weight, containing a support 21 (for example, a three-beam) fixed to the neck 3 with a threaded hole 22 in the center, an adjusting screw 23, plates ku 24 and a spring 25. A protrusion 26 is made on the body of the tank 1 for the formation of a damping cavity, and a chamber 27 is installed above the neck 3, in which an exhaust valve 6 and partially a safety valve 2 are placed, and the camera simultaneously acts as a barrier enclosing the service tank 1 personnel from direct exposure to discharged from the working fluid, which through the drain line 28 enters the drain tank 15 of the pump unit 14.

The system operates as follows. The spring 25 with the help of an adjusting screw 23 mounted on the thread in the hole 22 of the three-beam support 21 and the poppet 24 compensates for the weight of the exhaust valve 6 and possible inaccuracies in the manufacture of the piston 7 and its sealing with the pressure relief valve body with an area valve. The coil 11 is energized through the relay 13 and a force is applied to the seat 4 of the neck 3 of the exhaust valve 6, which prevents the valve from opening. When the pneumatic device is operating with the manipulator 20 open, air 1 is supplied to the reservoir 1 filled with the working fluid by means of the filling valve 16 to form an air cushion in the damping cavity 26. Then the manipulator 20 and the filling valve 16 are closed, and the air pressure transducer 18 into hydrostatic is half filled with working fluid. After that, with the manipulator 19 open, with the help of the filling valve 16 in the tank 1, the control cavity 8 and the cylinder 9, a set pressure corresponding to the conditions of the forthcoming operation is created. Before starting work by means of the manipulator 19, the connection between the control cavity 8, the cylinder 9 and the balloon transducer 18 is interrupted. The exhaust valve 6, due to the equality of the sealing areas of the piston 7 and the seat 4, is balanced by the same pressure from the side of the control cavity 8 and from the side of the tank 1. When the pressure in the tank 1 increases, the exhaust valve 6 opens, bleeding off the excess water, which is maintained inside the tank 1 constant pressure setpoint. Water discharged from the tank 1 is collected in the storage chamber 27, from where it is returned to the drain tank 15 through the drain line 28.

The system can operate by bleeding air from tank 1. To do this, with the manipulator 20 open, an air cushion is created in it under the set pressure.

Thus, by automatically unloading the exhaust valve 6 at any set pressure due to the equality of the sealing areas with the piston of the tail of the exhaust valve and the seat in the neck of the tank, a high sensitivity of the maintenance of the constant pressure system in the tank is achieved, the introduction of the compression device ensures greater safety of work, and the use of the device unloading from the weight of the exhaust valve makes it possible to further increase the accuracy of maintaining a constant value in the tank from its weight working pressure.

Claims (5)

1. A system for maintaining constant pressure in the tank, including a safety valve, consisting of a cylindrical body mounted on a tank neck made with a saddle, and an exhaust valve with a shank located inside this body and loaded with a pressing device, characterized in that the system for maintaining constant pressure in the tank is equipped with a pumping unit for filling the tank with a working medium, a pneumatic setpoint device for the stationary pressure in the tank connected to by means of manipulators to the reservoir and to the over-piston cavity formed by the body of the safety valve and the tail of the exhaust valve, made in the form of a piston sealing this cavity, the system is also equipped with a device that unloads the exhaust valve from its weight, while the safety and exhaust valves are partially placed in the chamber, mounted on the tank. 2. The system according to claim 1, characterized in that the device for pneumatic setting of the stationary pressure in the tank is made up of manipulators, a manometer and an air pressure to hydrostatic converter. 3. The system according to claim 1, characterized in that the pump unit for filling the reservoir with a working fluid is connected to a pneumatic device for setting the stationary pressure in the reservoir by means of a balloon transducer of air pressure to hydrostatic. 4. The system according to claim 1, characterized in that the device compressing the shank of the piston of the exhaust valve is made in the form of a core of a magnetic coil. 5. The system according to claim 1, characterized in that the device, which unloads the exhaust valve from its weight, is made in the form of a support fixed in the neck of the tank with a threaded hole in the center and a spring, adjustable by installation force.