One, the working principle of temperature reducing pressure reducing valve
Pressure P1 compressed air, input from the left end of the valve port 10 throttling, the pressure drop for P2 output. the size of P2 can be adjusted by the regulator spring 2, 3. Clockwise rotation of the knob 1, compression springs 2, 3 and diaphragm 5 so that the spool 8 down, increase the opening of the valve port 10 so that the P2 increase. If the knob 1 is rotated counterclockwise, the opening of the valve port 10 decreases, and P2 decreases accordingly.
If P1 instantly rise, P2 will rise, so that the diaphragm gas chamber 6 pressure increases in the diaphragm 5 on the corresponding increase in thrust, this thrust destroys the original balance of forces, so that the diaphragm 5 upward movement, a small portion of the gas flow through the overflow holes 12, the exhaust holes 11 discharged. At the same time in the diaphragm upward, due to the role of the reset spring 9, so that the spool 8 also move upward, shut down the inlet valve port 10, throttling effect increases, so that the output pressure drops until the new balance is reached, the output pressure is basically back to the original value. If the input pressure drops instantaneously, the output pressure also drops, the diaphragm 5 moves down, the spool 8 moves down, the inlet valve port 10 opens, the throttling effect decreases, so that the output pressure is also basically back to the original value. Counterclockwise rotation of the knob 1, so that the adjusting spring 2, 3 relaxation, the gas acting on the diaphragm 5 thrust is greater than the force of the regulating spring, the diaphragm upward curvature, rely on the role of the reset spring to close the
Inlet valve port 10. and then rotate the knob 1, the inlet valve spool 8 and the tip of the overflow valve seat 4 will be disengaged, the diaphragm air chamber 6 compressed air through the overflow holes 12, the exhaust holes 11, so the valve is in the no Output state.
When the output pressure of the pressure reducing valve is higher or larger diameter, with the regulator spring directly regulator, the spring stiffness must be too large, the flow rate changes, the output pressure fluctuations, the valve structure will also increase the size. In order to overcome these shortcomings, pilot operated pressure reducing valves can be used. Pilot-operated pressure reducing valve working principle and direct-acting basically the same. The regulating gas used in pilot operated pressure reducing valves is supplied by a small direct-acting pressure reducing valve. If a small direct-acting pressure reducing valve is installed inside the valve body, it is called an internal pilot-operated pressure reducing valve; if a small direct-acting pressure reducing valve is installed outside the main valve body, it is called an external pilot-operated pressure reducing valve. Compared with the direct-acting type pressure reducing valve, the valve adds a nozzle baffle amplification link consisting of a nozzle 4, a baffle fixed throttling orifice 9, and an air chamber B. The nozzle baffle amplifies the pressure reducing valve. When the distance between the nozzle and the baffle plate occurs a small change, it will make the pressure in the chamber B root obvious changes, thus causing the diaphragm 10 has a large displacement, to control the spool 6 up and down movement, so that the inlet valve port 8 open or close the small, improve the spool control of the sensitivity of the valve, that is, to improve the accuracy of the stabilized pressure.
The constant value is a high-precision pressure reducing valve, mainly used for pressure constant value. At present, there are two pressure specifications of the fixed value: its gas source pressure were 0.14MPa and 0.35MPa, the output pressure range of 0-0.1MPa and 0 a 0.25MPa. The output pressure fluctuation is not greater than 1% of the maximum output pressure, commonly used in the need to supply accurate gas source pressure and signal pressure of the occasions, such as pneumatic experimental equipment, pneumatic Pneumatic automatic devices.
Because of the fixed value of the use of output pressure feedback and the amplification of the nozzle baffle control of the main valve, so that it can respond to small pressure changes, so that the output pressure is adjusted in a timely manner to maintain the basic stability of the export pressure, that is, the fixed value of the pressure stabilizer accuracy is high.
Second, the basic performance of the temperature reducing valve
(1) regulating range: it refers to the regulator output pressure P2 adjustable range, in this range requires to achieve the specified accuracy. Regulating range is mainly related to the stiffness of the regulator spring.
(2) pressure characteristics: it refers to the flow rate g for a fixed value, due to input pressure fluctuations caused by output pressure fluctuations in the characteristics. The smaller the output pressure fluctuation, the better the characteristics of the pressure reducing valve. Output pressure must be lower than the input pressure - a fixed value to basically do not change with the input pressure changes.
(3) flow characteristics: it refers to the input pressure - fixed time, the output pressure with the output flow rate g changes and changes in persistence. When the flow rate g changes, the smaller the change in output pressure, the better. Generally the lower the output pressure, it is with the change in output flow rate fluctuation is smaller.
Three, the selection of temperature-reducing pressure reducing valve
Selected according to the use of the requirements of the type of pressure reducing valve and regulating accuracy, and then according to the required maximum output flow rate selection of its diameter. Decide to valve the pressure of the gas source, should be greater than the maximum output pressure 0.1MPa. Pressure reducing valve is generally installed in the water filter, oil mist or before the value of the device, and pay attention not to its inlet and outlet reversed; the valve should be used to relax the knob, so as to avoid frequent deformation of the diaphragm under pressure and affect its performance.
The installation and maintenance of the temperature reducing pressure reducing valve should pay attention to the following matters:
1, in order to operate and maintain the convenience of the valve is generally installed in the horizontal pipeline upright.
2, the installation should be careful to make the pipeline medium flow direction and the direction of the arrow shown on the valve rest.
3, in order to prevent the pressure after the valve overpressure, should be no less than 4M from the valve outlet to install a pressure reducing valve.
Four, temperature reducing pressure reducing valve technical parameters:
1, nominal pressure: 1.0MPa, 1.6MPa, 2.5MPa
2, shell test pressure: P = 1.5PN
3, sealing test pressure: P = 1.1PN
4, outlet pressure: PN1.0MPa regulating valve 0.09~0.8MPa
4, the outlet pressure: PN1.0MPa, 0.09~0.8MPa. 0.8MPa
PN1.6MPa regulating valve 0.10~1.2MPa
PN2.5MPa regulating valve 0.15~1.6MPa
5.Applicable medium: water
6.Applicable temperature: 0℃～80℃
Description of temperature reduction and pressure reduction devices
One, product overview
The new generation of temperature and pressure reducing device is optimized and designed by our company based on decades of design and manufacturing experience, summarizing the traditional domestic technology and absorbing the advanced foreign technology.
This device is mainly used in the heating system, can be sent to the power station or industrial boiler as well as thermal power plants and other places to reduce the pressure and temperature of the steam to the user's steam parameters.
Temperature and pressure reduction devices are divided into temperature and pressure reduction devices, temperature reduction devices and pressure reduction devices according to needs. According to the high and low steam parameters can be divided into medium temperature and medium pressure, high pressure and high temperature and high pressure temperature and pressure reduction device.
Second, product applications
1, cogeneration heat network centralized heat supply.
2, power stations or industrial boilers and thermal power plants.
3, heat exchange station or heat exchanger steam inlet.
4, lithium bromide refrigeration unit steam power inlet.
5, petrochemical, textile, paper, pharmaceutical, food and other production process equipment power and heat.
Three, structure and performance
The device consists of a control system, decompression system, water spraying and temperature reduction system and safety protection system. Its features are as follows:
1, control system: the main controller adopts the original imported high-precision multi-function digital controller, with powerful functional components, friendly man-machine interface and fast and accurate PID control loop, to achieve intelligent unattended, flexible adjustment of the parameter settings, and can be extended according to user requirements.
2. Pressure Reducing Device: The process of steam decompression is realized by the throttling of pressure reducing valve and throttling orifice plate, and the number of pressure reducing stages is determined by the difference of steam pressure after new steam decompression. The pressure adjustment of the pressure reducing valve is accomplished by a large actuator electric actuator, which operates smoothly and has a long service life. According to the requirements of the secondary steam setting value, the secondary positive gas pressure can be kept stable regardless of the fluctuation of the primary steam pressure.
3, temperature reduction device: the use of aerodynamic technology specially designed to reduce the temperature of the water atomization device, the use of the fluid's own power to reduce the power consumption of the equipment, reduce the temperature of the water that is crushed into a mist of water droplets and steam mixed with the rapid and complete evaporation, thereby reducing the temperature of the steam to achieve the role of the role. Atomization effect is good, (atomized particle diameter ≤ 500um) can effectively avoid cavitation and flash steam, adjustable than high.
Four, performance characteristics:
1, compact structure, the use of flange butt, easy installation and maintenance.
3, low noise (≤ 75dB), lower than the relevant national standard requirements.
4, flexible operation, according to the different requirements of any set parameters.
5, powerful functions, and can be extended according to user requirements.
6, high control accuracy, smooth operation, sensitive regulation, can effectively remove the static difference effect.
7, according to the user's production process requirements, temperature reduction and humidification. (Special design is required)