GB759380A - Improvements in air heating apparatus - Google Patents

Abstract

759,380. Air-heating stoves. BUREAU TECHNIQUE J. DENIS SOC. p.r.l. Nov. 12, 1953 [Nov. 12, 1952], No. 31385/53. Class 64(1). An air heater comprises a heat-exchanger 10, an adjacent heating chamber 9 which is larger in over-all crosssection than the heatexchanger, and an outer shell comprising two parts, an upper part 1 which fits closely around the upper part of the heat-exchanger 10 and a lower part 2 which has a larger cross-section than the part 1 and surrounds and is spaced from the chamber 9 and the lower part of the heatexchanger. In the form shown, the chamber 9 is a combustion chamber with an oil burner 15, and the heat-exchanger comprises four tubes of elongated cross-section. The combustion gases flow through the tubes to the outlet 14, and the air to be heated is forced by a fan 5 through the space between the chamber 9 and shell part 2 and through the spaces between the tubes to outlets 8. The tubes have internal and external fins 24. Near the ends of the tubes the external fins are oriented as shown to guide the air flow. The lower ends of the tubes may have refractory linings. In another form, four flanged finned parallel plates are assembled with their flanges in contact within a casing of rectangular crosssection to form two vertical hot-gas passages alternating with three air passages. The heating chamber and lower shell part are cylindrical and the air may be supplied tangentially to the space between them. Specification 744,963 is referred to.