Heater for fluids

A method of fabricating a heat exchanger, comprising the steps of:

• (a) making a plurality of apertures in a pair of corrosion-resistant metal plates;
• (b) swaging flanges in said metal plates surrounding said apertures, said step of swaging including the steps of successively placing each of said metal plates between a pair of mating dies and urging said dies together to form said flanges through a flowing of the metal of said metal plate;
• (c) inserting a first end of each of said tubes into a corresponding said flanged aperture in a first of said pair of plates;
• (d) inserting a second end of each of said tubes into a corresponding said flanged aperture in a second of said pair of plates;
• and
• (e) sealingly installing headers on either side of said assembly resulting from steps (a) through (c) to form a heat exchanger.

A corrosion resistant heat exchanger, comprising:

• (a) a pair of spaced, parallel, stainless-steel tubesheets with a plurality of corrosion-resistant tubes running therebetween and sealingly received within mating apertures in each of said tubesheets;
• (b) a plastic front header;
• and
• (c) a plastic rear header, said front header and said rear header sealingly attached to a corresponding one of said tubesheets, one of said headers having an inlet and one of said headers having an outlet for fluid, said mating apertures having forged flanges for increasing the area of contact between said tubesheets and said tubes, said tubes being internally expanded in said apertures.

A fluid heater comprising:

• (a) a metal housing;
• (b) a burner unit disposed in a bottom portion of said housing for burning combustible fuel;
• (c) a freestanding box-shaped combustion chamber having an open top and bottom disposed within said housing where combustible fuel is burned, said combustion chamber including four refractory panels and a metal framework, which is adjustable in at least one dimension, for holding said refractory panels in position relative to each other to form said combustion chamber and for urging said refractory panels into engagement with one another such that each panel sealingly engages an adjacent panel proximate longitudinal peripheral edges thereof to prevent the escape of heat and combustion products from said combustion chamber, said framework being adjustable via slotted holes that are elongated in the direction of adjustability, said holes receiving fasteners for retaining said refractory panels in their positions relative to each other, said fasteners being positioned in said elongated holes in selected positions associated with a given framework dimension and tightened to maintain them in said positions;
• and
• (d) a heat exchanger disposed substantially within said housing over said open top of said combustion chamber, said open bottom receiving heat from said burner unit generated from burning combustible fuel, said heat exchanger absorbing and conducting heat to a fluid to be heated.

A fluid heater comprising:

• (a) a metal housing;
• (b) a burner unit disposed in a bottom portion of said housing for burning combustible fuel;
• (c) a freestanding box-shaped combustion chamber having an open top and bottom disposed within said housing where combustible fuel is burned, said combustion chamber including four refractory panels and a metal framework, which is adjustable in at least one dimension, for holding said refractory panels in position relative to each other to form said combustion chamber and for urging said refractory panels into engagement with one another;
• and
• (d) a heat exchanger disposed substantially within said housing over said combustion chamber, said open bottom receiving heat from said burner unit and said open top accommodating said heat exchanger thereover such that said heat exchanger absorbs heat generated from burning combustible fuel and conducts heat to a fluid to be heated, said refractory panels including a pair of matched side panels of substantially equal dimensions, each extending from a bottom reference plane upwards to a first and second upper edge, respectively, a front panel extending from a first lower edge positioned above said first lower reference plane to a third upper edge extending above said first and second upper edges of said side panels, and a back panel extending from said bottom reference plane to a fourth upper edge extending to a height approximating that of said third upper edge, at least a portion of said burner unit being accommodated into said combustion chamber through a space between said first lower edge and said bottom reference plane, said space being further delimited by said side panels and said back panel, said heat exchanger being received between said front and rear panels and including a pair of spaced, parallel endplates with a plurality of tubes running therebetween and sealingly received within mating apertures in each of said endplates, a front header and a rear header removably attached to said endplates distal to said tubes for forming a circuitous conduit through said heat exchanger, said endplates straddling said side panels with said tubes contacting said first upper edge and said second upper edge, and said framework including a pair of sideframe members, each of which supports a corresponding one of said side panels and includes a ledge for supporting a corresponding one of said endplates.

A fluid heater comprising:

• (a) a metal housing;
• (b) a burner unit disposed in a bottom portion of said housing for burning combustible fuel;
• (c) a freestanding box-shaped combustion chamber having an open top and bottom disposed within said housing where combustible fuel is burned, said combustion chamber including four refractory panels and a metal framework, which is adjustable in at least one dimension, for holding said refractory panels in position relative to each other to form said combustion chamber and for urging said refractory panels into engagement with one another;
• and
• (d) a heat exchanger disposed substantially within said housing over said combustion chamber, said open bottom receiving heat from said burner unit and said open top accommodating said heat exchanger thereover such that said heat exchanger absorbs heat generated from burning combustible fuel and conducts heat to a fluid to be heated, said refractory panels including a pair of matched side panels of substantially equal dimensions, each extending from a bottom reference plane upwards to a first and second upper edge, respectively, a front panel extending from a first lower edge positioned above said first lower reference plane to a third upper edge extending above said first and second upper edges of said side panels, and a back panel extending from said bottom reference plane to a fourth upper edge extending to a height approximating that of said third upper edge, at least a portion of said burner unit being accommodated into said combustion chamber through a space between said first lower edge and said bottom reference plane, said space being further delimited by said side panels and said back panel, said heat exchanger being received between said front and rear panels and including a pair of spaced, parallel endplates with a plurality of tubes running therebetween and sealingly received within mating apertures in each of said endplates, a front header and a rear header removably attached to said endplates distal to said tubes for forming a circuitous conduit through said heat exchanger, said front header receiving a plastic baffle plate in an interior hollow thereof for directing fluid flows through said heat exchanger, said plastic baffle plate having an elongated member from which a tailpiece extends in a first direction at approximately 90 degrees, said elongated member having at least one tine extending therefrom in the direction opposite to the tailpiece at 90 degrees to said elongated member, said tailpiece dividing said front header into an input portion and an output portion, said tine partitioning said front header into a plurality of chambers for directing a flow of said fluid to be heated through said tubes in circuitous fashion.

A fluid heater comprising:

• (a) a metal housing;
• (b) a burner unit disposed in a bottom portion of said housing for burning combustible fuel, said burner unit being mounted in cantilever fashion to said metal housing;
• (c) a combustion chamber disposed within said housing where combustible fuel is burned;
• (d) a heat exchanger disposed substantially within said housing over said combustion chamber, said heat exchanger absorbing heat generated from burning said combustible fuel and conducting heat to a fluid to be heated.

A fluid heater comprising:

• (a) a metal housing;
• (b) a burner unit disposed in a bottom portion of said housing for burning combustible fuel;
• (c) a combustion chamber disposed within said housing where combustible fuel is burned;
• and
• (d) a heat exchanger disposed substantially within said housing over said combustion chamber, said heat exchanger absorbing heat generated from burning combustible fuel and conducting heat to a fluid to be heated, said heat exchanger including a pair of spaced, parallel endplates with a plurality of tubes running therebetween and sealingly received within mating apertures in each of said endplates, a front header and a rear header removably attached to said endplates distal to said tubes, said front header having an inlet orifice and an outlet orifice for receiving and discharging, respectively, fluid to be heated, said front header being composed of plastic.

A fluid heater comprising:

• (a) a metal housing;
• (b) a burner unit disposed in a bottom portion of said housing for burning combustible fuel;
• (c) a combustion chamber disposed within said housing where combustible fuel is burned;
• and
• (d) a heat exchanger disposed substantially within said housing over said combustion chamber, said heat exchanger absorbing heat generated from burning combustible fuel and conducting heat to a fluid to be heated, said heat exchanger including a pair of spaced, parallel endplates with a plurality of tubes running therebetween and sealingly received within mating apertures in each of said endplates, a front header and a rear header removably attached to said endplates distal to said tubes, said front header having an inlet orifice and an outlet orifice for receiving and discharging, respectively, fluid to be heated, said front header being composed of plastic and including a plastic baffle plate therein for directing fluid flows through said heat exchanger, said plastic baffle plate having an elongated member from which a tailpiece extends in a first direction at approximately 90 degrees, said elongated member having at least one tine extending in the direction opposite to the tailpiece at 90 degrees, said tailpiece dividing said front header into an input portion and an output portion, said tine partitioning said front header into a plurality of chambers for directing a flow of said fluid to be heated through said tubes in circuitous fashion.