Blowdown Heat Recovery Units

no image View Working Principle

The Blowdown Heat Recovery System  comprises of:
- Blowdown Flash Vessel with accessories
- SS Heat Exchanger with accessories
- Flash Steam Distributor
- Single Orifice Float Trap at water outlet of Flash Vessel
- Thermostat and Circulation Pump for Soft Water

Comes as a skid mounted package
Steam boilers need to be blown down to control the level of total dissolved solids (TDS) in the boiler water. This is best achieved by using a TDS control system which will open a valve to allow boiler water to discharge when the TDS level rises above a pre-set limit. Relatively low TDS feedwater then replaces the discharged boiler water.
Upto 80% of the heat in this discharged boiler water can be recovered with a properly designed heat recovery system.

How the system works :

Flash steam is released from the hot blowdown water when the pressure drops after the TDS blowdown control valve. This mixture of flash steam and blowdown water is allowed to separate in the flash vessel. The design of the vessel ensures that flow velocities are low to promote good separation. The dry flash steam is then introduced, at low pressure, into the feedwater storage tank through the steam distributor or the flash condensing deaerator head. A float trap fitted to the outlet of the flash vessel drains the residual blowdown water.

From the trap, the residual blowdown water which is still hot at this point, is allowed to pass into the heat exchanger where it gives up its heat to the circulating cold make-up water. The cooled blowdown water then flows safely to drain. To conserve energy, the circulating pump is activated by a thermostat mounted on the blowdown water inlet to the heat exchanger. It will therefore only run when blowdown water is flowing.

User benefits :
• Can recover upto 80% of the heat from blowdown
• Reduces expensive treated make-up water by recovering flash steam
• Rapid pay-back time from complete system package
• Flash vessel designed and constructed to BS 5500 Category 3 for enhanced safety
• Stainless steel heat exchanger plates can be removed for examination without disturbing pipework
• Reduces temperature of blowdown water for safer disposal

Blowdown Heat Recovery System ensures zero wastage of heat from blowdown operation and results in saving of fuel in the boiler firing. The BHRS is designed to the specific blowdown and feedwater parameters varying on plant to plant basis. For customized design and solutions please call our helpline number (at top) or send us an enquiry.

Technical Documents