Air heater

Claim 2

A heat exchange shell capable of use in a furnace comprising: a. a substantially horizontal combustion chamber adapted to receive a relatively long burner and having a relatively long and narrow opening along its top for the passage of products of combustion; b. a heat exchange section integral with the combustion chamber formed of walls extending upwardly from the combustion chamber''s opening, the walls defining a passage which is in gas communication with the combustion chamber''s opening and which presents a relatively long and narrow bounding periphery to products of combustion ascending therethrough; c. a substantially horizontal collector duct integral with and above the heat exchange section having an outlet at one end and a relatively long and narrow inlet in gas communication with the heat exchange section''s passage; and d. a substantially horizontal, elongated baffle in the collector duct, the baffle extending lengthwise along the collector duct inlet and disposed substantially centrally with reference thereto, the baffle including a pair of elongated gas-diverting members diverging upwardly into the collector duct, and an elongated gas-flow-dividing fin below the gas-diverting members, the gas-diverting members and the fin being operable to effect uniform flow of ascending products of combustion in the heat exchange section along its length and into the collector duct and to divert ascending products of combustion along the interior walls of the coLlector duct.

Claim 3

The heat exchange shell claimed in claim 1 wherein each of the gas-diverting members is substantially flat.

Claim 4

The heat exchange shell claimed in claim 2 wherein the gas-flowing-dividing fin is substantially flat.

Claim 5

The heat exchange shell claimed in claim 1 wherein the gas-flow-dividing fin extends into the top of the heat exchange section.

Claim 6

The heat exchange shell claimed in claim 1 including a plurality of spaced-apart tabs extending laterally outwardly from the gas-diverting members and abutting against the interior walls of the collector duct to provide longitudinal support means for the baffle means, whereby the baffle means is spaced away from the interior walls of the duct to allow passage of the products of combustion along its length into the duct.

Claim 7

The heat exchange shell claimed in claim 1 including an indexing tab extending laterally from the front of each gas-diverting member exterior of the collector duct outlet, the tabs being secured to the front of the heat exchange shell to provide rigid support means for the baffle means.

Claim 8

A heat exchange shell for use in a furnace comprising; a. a combustion chamber which, in depth is long relative to its width, has an opening extending substantially the length of the combustion chamber for the discharge of products of combustion, and is adapted to receive a long and narrow burner; b. a heat exchanger section extending above and from the combustion chamber and having a long and narrow passage in communication with the opening in the combustion chamber, the passage being defined by serpentine walls each of which has at least two convolutions in mating relationship with the convolutions of the outer wall, the depth of the convolutions and the width of the passage being such that a plane extending the height of the passage and disposed in the passage is not intercepted by the walls, the walls being joined together along their front and rear edges by seams which follows the convolutions; c. a collector duct for receiving products of combustion from the heat exchange passage, the collector duct having a long and narrow inlet in communication with the upper end of the heat exchange passage and an outlet for the discharge of products of combustion from the shell; and d. baffle means in the collector duct extending substantially the length of the collector duct''s inlet for diverting products of combustion along the walls of the collector duct.

Claim 9

A heat exchange shell for use in a furnace comprising; a. a combustion chamber which, in depth is long relative to its width, has an opening extending substantially the length of the combustion chamber for the discharge of products of combustion, and is adapted to receive a long and narrow burner; b. a heat exchanger section extending above and from the combustion chamber and having a long and narrow passage in communication with the opening in the combustion chamber, the passage being defined by serpentine walls each of which has at least two convolutions in mating relationship with the convolutions of the outer wall, the depth of the convolutions and the width of the passage being such that a plane extending the height of the passage and disposed in the passage is not intercepted by the walls, the walls being joined together along their front and rear edges by seams which follows the convolutions; c. a collector duct for receiving products of combustion from the heat exchange passage, the collector duct having a long and narrow inlet in communication with the upper end of the heat exchange passage and an outlet for the discharge of products of combustion from the shell; and d. baffle means in the collector duct extending substantially the length of the collector duct''s inlet for diverting products of combustion along the walls of the collector duct.

Claim 10

The heat exchange shell claimed in claim 7 wherein where the serpentine walls meet the combustion chamber the curvature of one of the walls is such that it sees the combustion chamber and this wall is bowed outwardly sufficiently to avoid substantial contact with products of combustion passing through the opening in the combustion chamber by preventing such wall from moving inwardly into the path of such products of combustion because of the heating of the heat exchange section.

Claim 11

The heat exchange shell claimed in claim 8 wherein the walls of the heat exchange section are gradually tapered toward one another so that the serpentine heat exchange section passage gradually decreases in cross-sectioned area toward the collector duct.

Claim 12

The heat exchange shell claimed in claim 8 wherein the shell is fabricated from sheet metal complementary half-shells each having a peripheral rim secured to the peripheral rim of the other to provide a unitary structure with a seam spanning its entire outer periphery.

Claim 13

A hot air furnace comprising: a. a casing; b. a plurality of side by side heat exchange shells in the casing, each heat exchange shell including: i. a substantially horizontal combustion chamber having a relatively long and narrow opening along its top; ii. a heat exchange section integral with the combustion chamber formed of spaced apart serpentine walls extending upwardly from the combustion chamber''s opening, each of the spaced apart walls having at least two convolutions in mating relaTionship with the convolutions of the other wall to define a long and narrow serpentine heat exchange passage which is in gas communication with the combustion chamber''s opening for substantially the entire extent of such opening, the depth of the convolutions and the width of the passage being such that a plane extending the height of the passage and disposed in the passage is not intercepted by the walls, the walls being joined together along their front and rear edges by seams which follow the curvature of the convolutions; iii. a substantially horizontal collector duct integral with and above the heat exchange section having an outlet at one end and a relatively long and narrow inlet in gas communication with the heat exchange section''s passage; and iv. substantially horizontal, elongated baffle means extending lengthwise along the collector duct inlet and disposed substantially centrally with reference thereto to effect uniform flow of ascending products of combustion in the heat exchange section and into the collector duct, the baffle means having means to divert ascending products of combustion along the interior walls of the collector duct; c. burner means in each combustion chamber; d. blower means for directing air over the heat exchange shell''s outer surfaces; and e. vertical expansions for each of the heat exchange shells between the collector ducts and the casing.

Claim 14

A hot air furnace comprising: a. a casing; b. a plurality of side by side heat exchange shells in the casing, each heat exchange shell including: i. a substantially horizontal combustion chamber having a relatively long and narrow opening along its top; ii. a heat exchange section integral with the combustion chamber formed of spaced apart serpentine walls extending upwardly from the combustion chamber''s opening, each of the spaced apart walls having at least two convolutions in mating relaTionship with the convolutions of the other wall to define a long and narrow serpentine heat exchange passage which is in gas communication with the combustion chamber''s opening for substantially the entire extent of such opening, the depth of the convolutions and the width of the passage being such that a plane extending the height of the passage and disposed in the passage is not intercepted by the walls, the walls being joined together along their front and rear edges by seams which follow the curvature of the convolutions; iii. a substantially horizontal collector duct integral with and above the heat exchange section having an outlet at one end and a relatively long and narrow inlet in gas communication with the heat exchange section''s passage; and iv. substantially horizontal, elongated baffle means extending lengthwise along the collector duct inlet and disposed substantially centrally with reference thereto to effect uniform flow of ascending products of combustion in the heat exchange section and into the collector duct, the baffle means having means to divert ascending products of combustion along the interior walls of the collector duct; c. burner means in each combustion chamber; d. blower means for directing air over the heat exchange shell''s outer surfaces; and e. vertical expansions for each of the heat exchange shells between the collector ducts and the casing.

Claim 15

The furnace claimed in claim 11 wherein: a. the casing includes a substantially vertical faceplate mounted transverse to the casing''s sidewalls inwardly of the front of the furnace; b. the collector duct outlet and combustion chamber of each heat exchange shell extend forward of their heat exchange section toward the front of the furnace with the extension of the combustion chamber opening in a substantially vertical plane; and c. each heat exchange shell is vertically mounted in and rearwardly of the faceplate, with the combustion chamber and collector duct extensions projecting through the plate toward the front of the furnace.

Claim 16

The furnace claimed in claim 12 wherein the expansion means includes: a. a floating collar plate in which is disposed the collector duct extensions; b. insulation means between the collar plate and the faceplate; and c. fastener means securing the collar plate and the the faceplate together such that relative vertical movement between the secured members is possible.

Claim 17

The furnace claimed in claim 11 including air-diverting means on the interior wall of the casing facing an adjacent one of the heat exchange shells and positioned to force upwardly ascending air close to the exterior surface of the heat exchange section of such heat exchange shell at least where such exterior surface is relatively far from the casing interior wall.

Claim 18

The furnace claimed in claim 11 wherein each of the shells has one of the walls of the heat exchange section adjacent the combustion chamber which faces the combustion chamber and which is bowed outwardly sufficiently to prevent such wall from moving into the path of products of combustion when the heat exchange section is heated and to thereby avoid substantial contact with products of combustion passing from the combustion chamber.

Claim 19

The furnace claimed in claim 15 wherein each of the shells is fabricated from half shells of sheet metal with each half shell having a peripheral rim secured to the peripheral rim of its complementary half shell to provide a unitary structure with a seam around its entire outer periphery.

Claim 20

The furnace claimed in claim 11 wherein each of the heat exchange shell''s baffle means includes a pair of elongated gas-diverting members diverging upwardly from a line of meeting of such members proximate the collector duct inlet in the middle of such inlet, and a flow-dividing fin depending from the gas-diverting members into the heat exchange passage to divide the flow from such passage substantially equally past the gas-diverting members and along the walls of the collector duct.