Flexible gas-fired heat exchanger system

Abstract

A compact, highly flexible and efficient, multi-positionable, multi-dimensional and multi-stage gas-fired heat exchanger system as described. The system is connectable in a forced air duct regardless of the angular position and size of the duct. The heat exchanger comprises one or more heat transfer tubes which are shaped and dimensioned as dictated by the customized use of the heat exchanger. The tubes are secured to a support panel as well as the gas burner associated with each of the inlet openings of the tubes. A position orientable gas valve is secured to a gas distribution manifold. A turbulator may be associated with at least some of the tubes to cause turbulence in the hot combustion flow in each of the tubes to modify the efficiency in heat transfer along one or more sections of the tubes by directing hot combustion gas along an inner circumferential wall of the tubes. The outlet of the tubes connect to a collector which has an exhaust fan which is position orientable to suit the installation of the heat exchanger in the duct.

1 . A compact, highly flexible and efficient, multi-positionable and multi-dimensional gas-fired heat exchanger system for use in a forced air duct, said heat exchanger comprising one or more heat transfer tubes, each said tube having a shape and dimension dictated by a predetermined customized use of said heat exchanger, said tubes being secured to a support panel, a gas burner mounted on said support panel and disposed for directing a flame at an inlet opening of an associated one of said heat transfer tubes, a gas distribution manifold for supplying gas to said burners, a position orientable gas valve secured to said manifold and connectable to a gas supply line, said gas valve being disposed horizontal regardless of the angular position of said system when secured to a duct, said tubes each having an outlet connected to combustion product position orientable exhaust means secured to said support panel, and control means to control the operation of said burners dependent on heat requirements.  
     
     
         2 . A heat exchanger system as claimed in  claim 1  wherein there is further provided gas flow turbulence inducing means associated with at least some of said tubes to cause turbulence in a hot combustion flue-gas flow in each said tubes to modify the efficiency in heat transfer along one or more sections of said tubes by directing hot combination flue-gas along an inner circumferential wall of said tubes.  
     
     
         3 . A heat exchanger system as claimed in  claim 2  wherein said support panel is provided with attachment means to secure same in a hole formed in a ventilation duct regardless of the angle of disposition of said duct.  
     
     
         4 . A heat exchanger system as claimed in  claim 2  wherein said gas flow turbulence inducing means is comprised by an elongated rectangular flat plate having a plurality of deflection sections, said deflection sections having corner angled sections extending to opposed sides of said flat plate to form deflection sections of octagonal contour, said deflection sections being disposed at an angle with respect to one another to form a twisted turbulator to force said combustion gas flow away from the center of said tubes to an inner surface thereof.  
     
     
         5 . A heat exchanger system as claimed in  claim 4  wherein said twisted turbulator is positioned in an outlet section of said tubes.  
     
     
         6 . A heat exchanger system as claimed in  claim 4  wherein said deflection sections are of different sizes along elongated sections of said plate, said twisted turbulator being severable into a desired length.  
     
     
         7 . A heat exchanger system as claimed in  claim 4  wherein said deflection sections are disposed at predetermined equidistantly spaced angles with respect to a longitudinal central axis of said turbulator whereby these sections extend all about said central axis, larger ones of said deflection sections having a transverse maximum length for frictional engagement with said inner surface of said tubes.  
     
     
         8 . A heat exchanger system as claimed in  claim 6  wherein said tubes are U-shaped tubes, therebeing disposed a further twisted turbulator in a forward section of said tubes spaced from said inlet opening of said tubes in an area where there is no flame when the associated burner is operative.  
     
     
         9 . A heat exchanger system as claimed in  claim 1  wherein there is further provided an air/gas turbular plate having one or more orifices each said orifices being dimensioned to fit about a respective one of said inlet opening of said one or more tubes, each said one or more orifices having inwardly extending deflector flanges disposed side-by-side thereabout to increase turbulence at said inlet openings where said flame is injected to diminish the laminar secondary air flow and to maximize thermal exchange with said tubes.  
     
     
         10 . A heat exchanger system as claimed in  claim 1  wherein said position orientable exhaust means comprises a collection housing for receiving combustion gas from said outlet of said one or more tubes and an exhaust fan secured to an outlet port of said collection housing, said exhaust fan having an adjustable shroud with an exhaust whereby said exhaust port can be oriented at a desired angle for connection to a flue regardless of the angular position of said support panel and consequently said collection housing.  
     
     
         11 . A heat exchanger system as claimed in  claim 1  wherein said heat exchanger is a multi-stage heat exchanger having a plurality of said one or more heat transfer tubes, said tubes being dimensioned in accordance with a desired diameter, length and shape dependent on a desired heat generating capacity and the dimension of a space in said duct where said heat exchanger is to be secured.  
     
     
         12 . A heat exchanger system as claimed in  claim 11  wherein said control means is a control circuit having a plurality of control connections for controlling the operation of a solenoid valve secured to each said burner associated with each said heat transfer tubes, thermostatic controls feeding command signals to said control circuit whereby said control circuit will operate said burners independently to control air temperature dependent on said command signal.  
     
     
         13 . A heat exchanger system as claimed in  claim 12 , wherein said burners are venturi type burners have a predetermined heat rate of 17.5K BTU/h, 23.5K BTU/h, 30K BTU/h and 50K BTU/h.  
     
     
         14 . A heat exchanger system as claimed in  claim 12 , wherein said heat transfer tubes are connected in a stack, each tube having said inlet and outlet end thereof secured to said support panel whereby said tubes extend in a horizontal plane and parallel to one another with respect to said support panel, a burner support bracket to support said burners in alignment and spaced a predetermined distance from said inlet end of each said tubes, said inlet ends being aligned with one another along a vertical axis of said support panel, said gas distribution manifold being comprised of a vertical pipe to which said solenoid valves are connected, said support panel being accessible exteriorly of said air duct.  
     
     
         15 . A heat exchanger system as claimed in  claim 14 , wherein a thermal insulating sheet is secured to an outer surface of said support panel to protect said panel from hot flames of said burners.  
     
     
         16 . A heat exchanger system as claimed in  claim 14 , wherein said heat exchanger is secured in a support frame comprising a bottom and top wall secured to a bottom and top edge of said support panel, and a rear wall secured between rear edges of said top and bottom walls; said rear wall, top and bottom walls having predetermined dimensions and flange means to secure same in said air duct to orient said tubes for heat exchange with air flow in said duct when a blower pushes air through said duct for heating convected air.  
     
     
         17 . A heat exchanger system as claimed in  claim 16 , wherein said top and bottom walls are provided with air deflecting flanges projecting in said air flow to cause air turbulence in said convected area of said heat transfer tubes to improve heat transfer between said tubes and said convected air.  
     
     
         18 . A heat exchanger system as claimed in  claim 16 , wherein said rear wall is provided with a vertical tube support flange to support a far end section of said heat transfer tubes to maintain them in spaced parallel relationship.  
     
     
         19 . A heat exchanger system as claimed in  claim 14 , wherein there is further provided heat exchange clamps having a plurality of projecting flanges, said heat exchange clamps being secured to at least some of said tubes along an inlet section thereof where said tubes are at a higher temperature for additional heat exchange with convected air displaced in said duct.  
     
     
         20 . A heat exchanger system as claimed in  claim 1 , wherein said heat transfer tubes are one of U-shape, W-shape, square-shape, or other suitable shape for heat exchange with convected air displaced in said duct.  
     
     
         21 . A heat exchanger system as claimed in  claim 12 , wherein said position orientable gas valve is a single or two stage or full modulated valve; said burners being operated independently by control of said solenoids; said position orientable gas valve, when a two stage valve, permitting the control of the temperature of said heat exchange in the range of from about 5% to 100% of the maximum thermal heat exchange capacity of said heat exchanger.  
     
     
         22 . A heat exchanger system as claimed in  claim 11 , wherein there is further provided a computer software to calculate specific physical parameters for the construction of said heat exchanger dependent on input information relating to (1) the dimension of said duct where said heat exchanger is required to be installed, (ii) the volume of air to be heated, (iii) the static pressure of the forced air system, (iv) the temperature of air convected upstream of said heat exchanger and (v) the desired temperature downstream of said heat exchanger; said physical parameters including the configuration of said heat transfer tubes, the quantity of said tubes, the diameter and length of said tubes and the thermal capacity of said burners.  
     
     
         23 . A heat exchanger system as claimed in  claim 1 , wherein said heat exchanger is mounted in a protective housing having an intake means, a gas line entry port, electric wiring connections and exhaust ports to permit said heat exchanger to be oriented in a duct at any desired position.  
     
     
         24 . A heat exchanger system as claimed in  claim 14 , wherein a component mounting plate assembly is secured to said support panel and extends outwardly on a vertical axis spaced from said burners and manifold for housing associated hardware and to make them accessible on said support panel to provide ease of maintenance, repair and modification to said heat exchanger system.