Blowdown Tanks:  Manage Temperature and Pressure

Boiler blowdown tanks are used to reduce the pressure and temperature of the blowdown from a boiler.  IN most states, it is unlawful to discharge blowdown directly into the sewer system.  They typically required boiler blowdown to be reduced to a temperature of 14 F at a maximum pressure of 5PSIG.

The pressurized design allows for heat recovery with the flas steam discharged to the deaerator, or low pressure steam header, and the effluent water passing through a heat exchanger, poisitioned upstream of the deaerator level control valve, to effect make up water tempering.

Blowdown from the boiler is received in the upper part of the blowdown tank.  Because the tank is vented, or connected to a low pressure header, approximately 30% of the blowdown flashes into steam and flows out the vent.  The saturated water that remains falls to the lower half of the tank and forces cold water from the bottom of the tank out the discharge.

Precision Boilers offers blowdown tanks in a variety of sizes.