What is prds system?
PRDS: Pressure Reducing and DeSuperheating System. It is a combination of Control Valve for the pressure reduction purpose & atomizing nozzles, through which water is sprayed into steam for reducing the temperature.
What is the function of a desuperheater?
The primary function of a desuperheater is to lower the temperature of superheated steam or other vapors. This temperature reduction is accomplished as a result of the process vapor being brought into direct contact with another liquid such as water. The injected water is then evaporated.
How does a steam pressure reducing valve work?
Steam reducing pressure valves are valves that precise control the downstream pressure of steam and automatically adjust the amount of valve opening to allow the pressure to remain unchanged even when the flow rate fluctuates by pistons, springs or diaphragms.
How does desuperheater control the exit temperature from superheater?
When the desuperheater is operational, a measured amount of water is added to the superheated steam via a mixing arrangement within the desuperheater. As it enters the desuperheater, the cooling water evaporates by absorbing heat from the superheated steam. Consequently, the temperature of the steam is reduced.
What is an Attemperator in boiler?
Attemperator is a spray of water to reduce the steam temperature that is limited as per the operational requirements. An Attemporator spray reduces the steam temperature in the superheater zones of a boiler so as to maintain around 535-540 degree centigrade temperature at the inlet of the steam turbine.
What is a control valve used for?
What are Control Valves? Control valves are used in many processes to control flow, pressure, temperature or other variables. The type of valve used will depend on the size of the pipe, the overall pressure that the system operates, the flowing media, process conditions, and other factors.
What is the function of Attemperator in boiler?
Boiler attemperators are used to fine tune / control steam temperature from a boiler, as well as the steam temperature between boiler stages.
What is the difference between Attemperator and desuperheater?
is that desuperheater is a device that reduces the temperature of superheated steam, and recovers useful heat in the process while attemperator is a device that regulates the temperature (especially in a boiler) by passing hot or cold water through a coil of piping.
What is the function of pressure reducing valve?
Pressure reducing valves (PRV) lower the downstream pressure to match the setpoint, opening as the pressure falls and closing as it rises. These mechanical valves employ a spring against a diaphragm or piston as the control element which makes them simple and reliable in operation.
How does the reducing valve work?
It is often referred to as a pressure regulator. The valve simply uses spring pressure against a diaphragm to open the valve. When the outlet pressure drops below the set point of the valve, the spring pressure overcomes the outlet pressure and forces the valve stem downward, opening the valve.
What is the purpose of Attemperator?
What is ESD boiler?
The original External Superheater ‘D’ (ESD) type of boiler used a primary and secondary superheater located after the main generating tube bank . An attemperator located in the combustion air path was used to control the steam temperature.
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