The periodic blowdown tank is to separate the secondary steam and waste hot water from the periodic drain water through decompression and expansion. The secondary steam is discharged into the atmosphere or used as a heat source, and the waste hot water is generally discharged into the groundwater system through the sewage cooling pool.
The continuous blowdown tank is connected with the continuous drain outlet of the boiler, which is used to reduce the pressure and expand the capacity of the continuous drain water from the boiler, and then discharge. The secondary steam is introduced out by a special pipe, and generally enters the deaerator. The waste hot water is automatically discharged through the float level valve or overflow control valve, and generally enters the periodic blowdown tank. The heat energy can be recycled. The continuous blowdown volume is adjusted automatically with the change of boiler feed water load to maintain a relatively stable blowdown rate. The secondary steam and waste hot water can be used as heat sources to recover some of the heat lost by continuous blowdown in the boiler and improve boiler efficiency.