Water Heater System Having Venturi Draw System

Abstract

A water heater system comprises a water tank, a burner plenum, a flue, and a dilution air blower system. The dilution air blower system comprises a blower, a dilution air passageway, and a venturi system. Air from the blower is forced through the dilution air passageway and discharged toward the venturi system. When the dilution air blower system is attached to the water heater system, air discharged from the dilution air discharge passage via the blower passes through a converging region, throat region, diverging region and exit passage of the venturi system and draws combustion products through the flue and out the venturi system.

What is claimed is: 
     
         1 . A water heater system comprising a water tank, a burner plenum adjacent the water tank, a fuel burner within the burner plenum, a flue, a blower adapted and configured to blow air, a dilution air passageway, and a venturi system, the fuel burner being configured and adapted to combust fuel to produce hot combustion products, the flue having an upstream end and a downstream end, the upstream end of the flue being in fluid communication with the burner plenum, the flue being configured for passage of combustion products from the burner plenum through the water tank and toward the downstream end of the flue, the venturi system including a converging region, a throat region downstream of the converging region, a diverging region downstream of the converging region, and an exit passage downstream of the converging region, the dilution air passageway having a dilution air intake passage and a dilution air discharge passage, the dilution air passageway being in fluid communication with the blower, the blower and dilution air passageway being adapted and configured such that air from the blower is blown through the dilution air passageway and discharged via the dilution air discharge passage, the dilution air passageway being positioned relative to the converging region of the venturi system and configured such that air discharged from the dilution air discharge passage is directed downstream toward the converging region of the venturi system, the water heater system being adapted and configured such that air discharged from the dilution air discharge passage via the blower passes through the converging region, throat region, diverging region and exit passage of the venturi system and draws combustion products through the flue such that such combustion products pass through the converging region, throat region, diverging region, and exit passage of the venturi system, whereby air entering the converging region of the venturi system via the dilution air passageway and combustion products entering the converging region of the venturi system via the flue are discharged together via the exit passage of the venturi system. 
     
     
         2 . A water heater system as set forth in  claim 1  wherein the water heater system is configured such that the air and combustion products discharged from the exit passage of the venturi system have a temperature of less than 175° F. during operation of the water heater. 
     
     
         3 . A water heater system as set forth in  claim 1  wherein the water heater system is configured to cause the blower to force air through the dilution air passageway at a flow rate of between about 25 cubic feet per minute and about 50 cubic feet per minute during operation of the water heater system. 
     
     
         4 . A water heater system as set forth in  claim 3  wherein the water heater system is configured to cause air to be discharged from the dilution air discharge passage of the dilution air passageway at a velocity of between about 150 feet/second to about 220 feet/second. 
     
     
         5 . A water heater system as set forth in  claim 3  wherein the venturi system is configured to produce a pressure differential of more than about 2.5 inches of water and less than about 5 inches of water between the exit passage of the venturi system and the downstream end of the flue during operation of the water heater system. 
     
     
         6 . A water heater system as set forth in  claim 3  wherein the venturi system is configured to produce a pressure differential of at least 2.5 inches of water between the exit passage of the venturi system and the downstream end of the flue during operation of the water heater system. 
     
     
         7 . A water heater system as set forth in  claim 6  wherein the dilution air discharge passage of the dilution air passageway has a cross-sectional area and the throat region of the venturi system has a cross section area, the cross-sectional area of the dilution air discharge passage being less than the cross-sectional area of the throat region. 
     
     
         8 . A water heater system as set forth in  claim 6  wherein the cross-sectional area of the dilution air discharge passage is less than about 75% of the cross-sectional area of the throat region. 
     
     
         9 . A water heater system as set forth in  claim 1  wherein the water heater system is adapted and configured such that at least a portion of the venturi system is positioned directly above the flue when the water heater system is operational. 
     
     
         10 . A water heater system as set forth in  claim 1  wherein the downstream end of the flue is adapted for discharging combustion products generally along a longitudinal flue axis, and wherein the exit passage of the venturi system is aligned with the longitudinal flue axis. 
     
     
         11 . A water heater system as set forth in  claim 10  wherein the dilution air passageway is configured to discharge air from the blower out the dilution air discharge passage along the longitudinal flue axis and upstream of the converging region of the venturi system. 
     
     
         12 . A water heater system as set forth in  claim 11  wherein the dilution air passageway comprises a conduit having a generally straight lateral portion adapted for directing air from the blower along a path that is generally perpendicular to the longitudinal flue axis. 
     
     
         13 . A water heater system as set forth in  claim 11  wherein the throat region of the venturi system is aligned with the longitudinal flue axis. 
     
     
         14 . A dilution air blower system adapted and configure to be used with a water heater system, the water heater system comprising a water tank, a burner plenum adjacent the water tank, a fuel burner within the burner plenum, and a flue, the fuel burner being configured and adapted to combust fuel to produce hot combustion products, the flue having an upstream end and a downstream end, the upstream end of the flue being in fluid communication with the burner plenum, the flue being configured for passage of combustion products from the burner plenum through the water tank and toward the downstream end of the flue to thereby heat water within the tank, the dilution air blower system comprising:
 a blower adapted and configured to blow air;   a dilution air passageway;   a venturi system;   the venturi system including a converging region, a throat region downstream of the converging region, a diverging region downstream of the converging region, and an exit passage downstream of the converging region, the dilution air passageway having a dilution air intake passage and a dilution air discharge passage, the dilution air passageway being adapted and configured to be in fluid communication with the blower, the blower and dilution air passageway being adapted and configured such that air from the blower is blown through the dilution air passageway and discharged via the dilution air discharge passage, the dilution air passageway being positioned relative to the converging region of the venturi system and configured such that air discharged from the dilution air discharge passage is directed downstream toward the converging region of the venturi system, the venturi system further including a combustion products intake passage upstream of and in fluid communication with the converging region, the combustion products intake passage of the venturi system being adapted and configured to be in fluid communication with the downstream end of the flue of the water heater system, the dilution air blower system being adapted and configured such that when the dilution air blower system is attached to the water heater system air discharged from the dilution air discharge passage via the blower passes through the converging region, throat region, diverging region and exit passage of the venturi system and draws combustion products through the flue such that such combustion products pass through the converging region, throat region, diverging region, and exit passage of the venturi system, whereby air entering the converging region of the venturi system via the dilution air passageway and combustion products entering the converging region of the venturi system via the flue are discharged together via the exit passage of the venturi system.   
     
     
         15 . A dilution air blower system as set forth in  claim 14  wherein the venturi system is configured to produce a pressure differential of more than about 2.5 inches of water and less than about 5 inches of water between the exit passage of the venturi system and the downstream end of the flue during operation of the water heater system. 
     
     
         16 . A dilution air blower system as set forth in  claim 14  wherein the venturi system is configured to produce a pressure differential of at least 2.5 inches of water between the exit passage of the venturi system and the downstream end of the flue during operation of the water heater system. 
     
     
         17 . A dilution air blower system as set forth in  claim 14  wherein the dilution air discharge passage of the dilution air passageway has a cross-sectional area and the throat region of the venturi system has a cross section area, the cross-sectional area of the dilution air discharge passage being less than the cross-sectional area of the throat region. 
     
     
         18 . A dilution air blower system as set forth in  claim 14  wherein the cross-sectional area of the dilution air discharge passage is less than about 75% of the cross-sectional area of the throat region. 
     
     
         19 . A dilution air blower system as set forth in  claim 14  wherein the water heater system is configured to cause air to be discharged from the dilution air discharge passage of the dilution air passageway at a velocity of between about 150 feet/second to about 220 feet/second.