Boiler Blowdown Tanks

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.

Blowdown Tanks
Dimensional Data

Components


Model Numbers, Ratings, and Dimensions

Model Number* Tank Volume Tank Size Design Press Drain (NPT) (in) Shipping Weight (lbs)
(gal) (cu.ft.) Dia (in) HT** (in)
BD-1636 30 4 16 36 50 2 320
BD-1648 40 5 16 48 50 2 380
BD-1660 50 7 16 60 50 2 450
BD2042 50 7 20 42 50 2 430
BD2060 75 10 20 60 50 2 540
BD-2078 100 13 20 78 50 2 660
BD-2454 100 13 24 54 50 2 590
BD-2468 125 17 24 68 50 2 700
BD-2482 150 20 24 82 50 2 810
BD-3062 175 23 30 62 50 2 800
BD-3070 200 27 30 70 50 2 870
BD-3086 250 33 30 86 50 2 1030
BD-3674 300 40 36 74 50 2 1090
BD-3686 350 47 36 86 50 2 1230
BD-3698 400 53 36 98 50 2 1370
BD-4282 450 60 42 82 50 2 1550
BD-4290 500 67 42 90 50 2 1660
BD-4298 550 73 42 98 50 2 1770
BD-4884 600 80 48 84 50 2 1800
BD-4898 700 93 48 98 50 2 2020
BD-4804 750 100 48 104 50 2 2120
BD-5490 800 107 54 90 50 2 2140
BD-5400 900 120 54 100 50 2 2320
BD-5410 1000 133 54 110 50 2 2500
BD-6092 1000 133 60 92 50 2 2470
BD-6000 1100 147 60 100 50 2 2630
BD-6008 1200 160 60 108 50 2 2780

*Other sizes and design pressures are available upon request.  **For total height, add 12″ for legs and
6″ for vent nozzle.

 

 Blowdown Tanks

Specification

Note:  items shown in parenthesis () are options.

Blowdown Tank shall be Model __________ as manufactured by Precision Boilers.  The pressure vessel shall be designed for 50 PSI and shall meet the applicable requirements for ASME Section VIII, U-stamped, and National Board Registered.  The manufacturer shall provide the owner with a copy of the Manufacturer’s Data Report.  The Tank shall have ______ gallon capacity (total volume), _____ (NPT) (FLG) tangential inlet with wear plate, and properly siz
ed (per National Board recommendations) vent, outlet and outlet restricting orifice.  The tank outer surface shall be painted with one coat of industrial grade red oxide primer.

Specifications subject to change without notice.

 Blowdown Tanks (pdf)