Heat exchanger for convection baking ovens

Claim 1

In an oven (1) for baking foods comprising an enclosed baking cabinet (2) for holding the foods, at least one door (3) for providing access to the baking cabinet, a plurality of burners (4) exterior to the baking cabinet (2) for combusting a fuel to hot combustion gases (5), a plurality of annular heat exchange tubes (6) exterior to the baking cabinet (2) for receiving in the annulus (7) of each tube (6) at an intake end (8) thereof the hot combustion gases (5) from the burners (4) so as to heat the heat exchange tubes (6) as the hot combustion gases (5) flow therethrough, a flue (9) in fluid communication with a discharge end (10) of each heat exchange tube (6) for conducting the combustion gases (5) out of the oven (1), and a blower device (11) for recirculating air from within the baking cabinet (2), over the heat exchange tubes (6) and back into the baking cabinet (2), the improvement comprising a first bracket (20) removably attached to the oven (1), a second bracket (21) attached to the oven (1) and spaced a distance from the first bracket (20), a plurality of annular heat exchange tubes (6) disposed between said brackets (20, 21) with the intake end (8) of each tube attached to the second bracket (21) and the discharge end (10) of each heat exchange tube (6) attached to the first bracket (20) so as to form a removable rack (25) of the heat exchange tubes (6), and each heat exchange tube forming a curved configuration such that the length of each heat exchange tube in the curved configuration is greater than a distance (X) between the brackets so that each heat exchange tube is independently free to expand and contract with heating and cooling of the heat exchange tubes without significant force being placed on the brackets and the tubes are curved such that the length of a curved configuration of each tube is less than the distance (X) between the brackets (20, 21).