Method and system of recovering the heat wasted from the steam boilers continuous blow down to preheat the boiler combustion air

• Main Author: MOLDOVANU VLADIMIR
• Format: Patent
• Language: English
• Published: 02.12.2010
• Subjects: AIR SUPPLY; BLASTING; CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS,e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USERAPPLICATIONS; COMBUSTION APPARATUS; COMBUSTION PROCESSES; DRAUGHT-INDUCING; ENGINE PLANTS IN GENERAL; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; HEAT EXCHANGE IN GENERAL; HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS,IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT; HEATING; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGYGENERATION, TRANSMISSION OR DISTRIBUTION; STEAM ACCUMULATORS; STEAM ENGINE PLANTS; STEAM ENGINES; SUPPLYING NON-COMBUSTIBLE LIQUID OR GAS; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE; WEAPONS

Heat from continuous blow down from a steam boiler is used to preheat boiler combustion air. Blow down from the steam boiler is fed through a flash tank and a 3-way valve to a liquid heat exchanger to heat a circulating liquid. The hot circulating liquid is fed to a preheat coil to heat combustion air for a steam boiler. A 3-way valve located between the flash tank and heat exchanger controls the flow of blow down to the heat exchanger. A temperature sensor which monitors the temperature of the circulating liquid controls the 3-way valve and a circulating pump moves the liquid around a closed loop. Motorized or variable frequency drive damper control the flow of air to the preheat coil and to the combustion air blower of the steam boiler.