Heat recovery apparatus and an improved heat recovery method

A heat recovery apparatus and flue gas recovery and/or recirculation and/or induced draft apparatus for boilers, or the like, comprising a heat recovery member and a flue gas recovery member secured to said heat recovery member and communicating therewith;

• said heat recovery member comprising a heat recovery housing having a first side member and a second side member, a pair of end members connected to said first side member and said second side member, a top and a bottom connected to said first side member and said second side member;
• said first side member having an aperture;
• a combustion gas inlet cone secured around said aperture of said first side member;
• a flue gas recovery housing comprising a fan shrouding means to convey a combustion gas secured to said first side member;
• a fan means disposed within said fan shrouding means and inside said combustion gas inlet cone to circulate a combustion gas;
• a motor coupled to said fan means to turn said fan means such that it may convey a combustion gas exiting said heat recovery member;
• a diverter means secured to one of the said end members to adjustably divert a determined quantity of said combustion gas to a flue gas recirculation duct;
• a flue gas recirculation duct means to convey a portion of a flue gas to a burner;
• a flue gas outlet duct member interconnected between said pair of end members and above said fan means and said diverter means;
• a flue gas damper member interposed in said flue gas outlet duct member having a flue gas damper shaft member attached thereto with said flue gas damper shaft member coupled to a flue gas damper lever member for pivotally operating the flue gas damper member to regulate the flue gas flow rate;
• and a flue gas damper actuator attached to the first side member and pivotally coupled to a flue gas damper lever member.

A process for recovering heat from hot combustion gases flowing through a combustion gas inlet in a bottom of a heat recovery housing additionally having a first pair of side walls including a flue gas exit in one of the side walls, a pair of end walls, a top, and a plurality of interconnected water conduit tubes provided with a roof and a cold water inlet in communication with one of said end walls to receive cold water and a hot water exit in communication with one of said end walls to dispense warm or hot water and circuitously passing through said heat recovery housing, and additionally recirculating back to a burner a portion of warm or hot combustion gases flowing from the flue gas exit of the heat recovery housing through a flue gas recovery and recirculation and induced draft housing comprising a second bottom, an arcuate end member, a generally upright cylindrical gas flue, a generally horizontal cylindrical recirculated gas flue, a fan, and a diverter member, said process comprising the steps of:

• (a) providing a heat recovery housing;
• (b) installing a first condensate drain in one of said first pair of side walls of said heat recovery housing;
• (c) securing an inlet cone member around the flue gas exit of the heat recovery housing;
• (d) providing a flue gas recovery and recirculation and induced draft apparatus;
• (e) disposing a second condensate drain in said second bottom;
• (f) securing a generally L-shaped condensate trap member above the condensate drain of step (e) to the second bottom;
• (g) securing a lip member to said diverter member for locking the diverter member into a secure position;
• (h) adjusting the diverter for regulating the amount of combustion gas that is to be recirculated;
• (i) rotating said fan for drawing the combustion gases through the flue gas recovery and recirculation and induced draft housing;
• (j) passing a first portion of combustion gas above the diverter member and through the generally upright cylindrical gas flue;
• (k) passing a second portion of combustion gas below the diverter member;
• (l) passing the second portion of combustion gas of step (k) through the generally horizontal recirculated gas flue;
• (m) passing the combustion gas of step (l) through a recirculating duct to burner.