GB940465A - Resistance-heated electric oven or kiln - Google Patents

Abstract

940,465. Mounting electric heating resistances in ovens or kilns. H. J. M. JERU. Oct. 20, 1961 [Oct. 27, 1960], No. 37729/61. Heading H5H. In an electric oven or kiln comprising heating resistances constituted by thin metal strips which form at least a part of the inner walls of the oven or kiln and support an outer thermally insulating lining, the resistances are supported by suspension means attached to an outer framework, the said means producing longitudinal tensioning of the resistances and allowing them to expand when heated. As shown in Fig. 1, heating elements in the form of parallel metal strips 1 are arranged transversely of the oven so as to form a vault 2 and side walls 3, 4. The strips are attached to a framework 7 by means of ties 6 and support a layer of thermal insulation 9 which may be constituted by comminuted refractory bricks covered with comminuted rock. Additional support for the strips is provided by an air inlet sheath 17, details of which are illustrated in Fig. 9 (not shown). The ties 6 are attached at their inner ends to stainless steel T-shaped members 10 (Fig. 4), the lateral arms 11, 12 of which support adjacent strips 1 with the aid of insulating tubes or rollers 13 and insulating washers 15, 16. Compensation for expansion of the strips is provided by springs 8 mounted on the members 10. Three alternative means for attaching the strips 1 to a supporting framework are described and illustrated in Figs. 5, 8, 10 (not shown). In a second example shown in Fig. 7, an oven is constituted by heating elements in the form of metal strips 70 mounted side by side on carrier bars 71 which are supported at their ends by ties 74, the upper ties incorporating springs 75 to produce tension in the strips. In a third example (Fig. 3, not shown), a kiln is constructed in a somewhat similar manner to the oven shown in Fig. 1, and differs mainly in the arrangement of the supporting framework. Means are also described and illustrated in Figs. 6a, 6b (not shown) for reinforcing the insulating material 9 (Fig. 1) by means of metal strips provided with projecting points which engage with the insulating material, pressure being applied to the strips by means of springs.