GB497688A - Improvements in means for controlling the draught in furnace flues - Google Patents

Abstract

497,688. Controlling draught in furnace flues ; temperature - responsive actuating-elements. TRETHEWEY, W. B. July 20, 1937, No. 20058. [Class 51 (i)] [Also in Group XIII] In a draught regulator of the kind described in Specifications 432,471 and 432,472, [both in Group XIII], means are provided, operable at will, to effect an artificial cooling of the thermostat below its normal working temperature and thereby cause it to adjust the damper system so as to maintain an increased flue temperature. In one form shown in Fig. 2, a damper 15 which controls both the flue 10 and the air inlet 14 is actuated by the bimetallic coiled strip 11. When it is desired to increase the temperature of the flue above normal, a shield 22 is moved from a side tube 20 over the coil which is then exposed to atmospheric air entering through ports 21. In the arrangement shown in Fig. 5 the coil 11 actuates through links 23, 24, 26 the flue damper 25 and the air inlet damper 15 and is pivotally mounted in the wall of the flue by a rod 28 one end of which passes through the flue wall and is provided with an operating arm outside the flue. The coil may be swung to the right where it is only partly exposed to the flue gases and to air entering through the damper opening or further into a recess 32 where it is exposed to air entering at 35. In a further modification an air inlet damper is provided in the wall of the recess and is opened by the coil when it is swung into the reeess.