Why do steam pipes need pressure reducing valves for pressure reduction?
When steam is being transported from a boiler at high pressure to the point of use of each piece of equipment, it is often controlled by pressure reduction.
Why does steam need to be depressurised? The main reasons are as follows:
1, Boilers usually produce high pressure steam, which reduces the size of the boiler, reduces the occurrence of wet steam and improves the dryness of the steam for long distance transport.
2, caused by changes in the density of steam, high pressure when the density of steam, the same diameter pipeline can be transported to high-pressure steam than low-pressure steam, the use of high-pressure steam transmission will reduce the size of the pipeline, saving costs.
3, the use of steam will be condensation, reduced pressure steam to reduce the pressure of condensate, to avoid the loss of condensate discharge flash steam, condensate discharge in low pressure energy loss is small.
4, due to the temperature and pressure of saturated steam is the corresponding, in the sterilization process and paper dryer surface temperature control will be installed pressure reducing valve to control the pressure, so as to control the temperature of the process equipment.
5, process equipment have their own design pressure, when the supply of steam pressure exceeds the needs of the process system will require pressure reduction, when some systems are used to generate low-pressure flash steam with high-pressure condensate, to achieve energy-saving purposes. When the flash steam generated is insufficient, it needs to be supplemented by pressure reducing valves to generate low pressure steam.
6, can reduce the steam load of the boiler, because at low pressure the enthalpy of steam is higher. 2.5MPa at enthalpy value of 1839kJ/kg, 1.0MPa at enthalpy value of 2014kJ/kg. therefore, low pressure steam is more suitable for equipment use.