GB742248A - Improvements relating to ovens and drying apparatus - Google Patents

Abstract

742,248. Bakers' ovens. WHITWORTHS HOLDINGS, Ltd., and STEINER, E. R. May 19, 1953 [May 29, 1952], No. 13652/52. Class 51 (2). [Also in Group XIII] The heating or cooling arrangement of a bakers' oven or of drying apparatus comprises a number of inlet ducts or channels of substantially rectangular cross-section and wedge-shaped in plan, the broader ends of the ducts or channels being open to admit heating or cooling gases, a number of outlet ducts or channels of substantially rectangular cross-section and wedgeshaped in plan, located alternately with the first mentioned ducts or channels with their narrow ends adjacent to the broader ends of the first mentioned ducts or channels, the broader ends of such outlet ducts or channels being open to allow escape of gases therefrom, the gases being allowed to flow in a turbulent manner from one duct or channel to an adjacent outlet duct or channel over one or both of the longitudinal edges of a partition between them. Fig. 1 shows a heating or cooling element assembled as above to form a rectangular duct having a diagonal baffle AFKJ extending for less than the full height of the duct, in order to create the turbulence in the gases passing through. A modified element, Fig. 2 (not shown), has the baffle spaced from both top and bottom of the duct. A bakers' oven, Fig. 3, comprises heating elements 2, 3 and 4 supplied with hot gases from a combustion chamber 7 by a fan 8 through a header 10 or an opening 5, the said gases being vented either from a header 11 or an opening 6, partly to a chimney 12, and partly back to the combustion chamber 7 through slots 16 controlled by a sleeve 15 actuated by a rod 17. In a rotary drier, Figs. 6 and 7, the charge material is dried on the outer surface of a rotary drum 22 spaced from a stationary, refractory-lined drum 20, which is formed with fins 21 extending towards but not touching the rotary drum 22, and forming therewith a series of heating elements according to the invention. Disposed inside the drum 20 is a combustion chamber 7 fired by a gas burner 17 and having a slotted sleeve 15 controlling recirculation ports as in the previous embodiment, a bulkhead 13, and a fan 8 driven by a motor 9. Hot gases from the combustion chamber are driven by the fan out of the left-hand side of the drum 20 into the heating elements, from which part passes through a perforated plate 32 into a flue 33, and part is re-circulated to the combustion chamber under control of the sleeve 15.