GB404328A - Improvements in tunnel kilns - Google Patents

Abstract

404,328. Tunnel kilns. HARROP CERAMIC SERVICE CO., 310, West Broad Street, Columbus, Ohio, U.S.A.-(Assignees of Hartford, F. M. ; and Brush, G. D. ; 310, West Broad Street, Columbus, Ohio, U.S.A.) May 6, 1932, No. 13089. Convention date, May 21, 1931. [Class 51 (ii).] In a tunnel kiln of the muffle type having longitudinally-extending combustion spaces 6 separated from the ware-containing portion 2 of the tunnel by heat-radiating plates 5, separately-fired combustion spaces or flues 13 are provided beneath the ware platforms 12 on the cars. The spaces 6 extend the length of the high temperature and preheating sections of the kiln and are fired by angularly directed burners 7, secondary air being admitted through ports 8 from the cooling-section C. Combustion products from the spaces 6, and air and gases from the tunnel proper are exhausted to a stack flue 9 under control of dampers 26a and 26 respectively. The ware platform 12 is supported by blocks 28 having bevelled ends facing burners 11, which deliver through ported blocks 16 forming the floors of the combustion spaces 6. These burners may be provided for the high temperature section only, or for both high temperature and preheating sections, and the products of combustion therefrom may pass into the tunnel through gaps between the platform and the tops of the blocks 16, or if these gaps are closed by sand seals formed as shown by depending ribs 19 and grooves 20, exhaust is effected through ported blocks 16<1> into the opposite combustion space. The plates 5 are supported in grooves 21 in the upper faces of the blocks 16 and are held loosely at their upper edges by projections 22, 23. The joints between adjacent plates are preferably unsealed, and deflecting surfaces 5b, Fig. 3, may be formed on their outer of the plates so that the stream of combustion products in the spaces 6 will tend to draw air and gases from the tunnel through the joints. The plates may be panelled, or may have corrugations running vertically, horizontally or at an inclination. Radiation over the height of the plates may be equalised by making them thicker towards the top, by coating them at the upper part with insulating material, by applying a graded coating, or by increasing the depth of horizontal corrugations towards the lower edges of the plates. A modification is described in which the roof of the tunnel proper is formed by an arch of heat radiating plates.