Boiler make-up water system
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For a low-pressure steam boiler with an operating pressure of 1.6 MPa and a capacity of 3 T/H, is it possible to use feed water that has not been deoxygenated? Is it acceptable if the pressure head of the water supply to the boiler is less than 0.02 MPa (the pressure of the water supplied by the boiler’s feed pump)?
In general, all steam boilers should be deoxygenated. Since the boiler is small, it is not necessary to use thermal deoxygenation methods; instead, normal-temperature filtration for deoxygenation or the addition of sulfite can be employed.
Of course, deoxygenation is necessary, because without it, oxygen corrosion can occur even in small boilers
Oxygen removal is required; the water supply pressure you mentioned should be based on the steam supply pressure! Its pressure must be higher than the steam supply pressure, and it must also overcome pipeline resistance!
As mentioned on the 3rd floor, steam boilers should all be deoxygenated. The make-up water head of the make-up water pump should be greater than or equal to the sum of 1.6 MPa and the pressure drop between the make-up water pump and the boiler outlet.
Small-tonnage boilers usually do not have deaeration devices; the outlet pressure of the boiler feed water pump must be sufficient, while the inlet pressure of the pump is not a concern.
According to the boiler room design specifications, the inlet pressure of the make-up water pump should be equal to the difference between the vaporization pressure of the liquid at the inlet of the feed water pump and the operating pressure of the water tank, plus the net positive suction head of the pump, as well as the pipeline resistance losses and a surplus of 3–5 KPa. Should the net positive suction head for the boiler feedwater pump be set at 2.1 meters? Could anyone with extensive experience in this area please help? I was temporarily assigned to work on the boiler room design.
As stipulated in the Safety Technical Inspection Regulations for Steam Boilers