Improvements in and connected with electrically heated boilers for heating tar and tar bitumen compounds

摘要

448,997. Automatic control systems. MOLYNEUX, J., 236, Station Road, Bamber Bridge, WILLIAMS, F., 21, Cannon Street, DEWHURST, H. H., Bank House, Pope Lane, Penwortham, HOON, F., Greengates, Hollinhurst Avenue, Penwortham, and MOLYNEUX, G. S., 236, Station Road, Bamber Bridge, all in Preston. June 29, 1935, No. 2006/36. Divided out of 447,789, [Group XI]. [Class 38 (iv)] Temperature.-A boiler for heating tar and like compounds is provided with main and auxiliary electric heating elements, the main elements being controlled thermostatically, a hand operated switch s for connecting the auxiliary elements to the main directly or through the thermostatic control, an indicating type fuse in the circuit of each element, and pilot lamps r, t for indicating when the main and auxiliary circuits are energized. The boiler is constructed as described in Specification 447,789, four with elements m in each duct K. The main switch p is provided with a coil B and a thermostat control g. A distribution board n carries the fuses E, F and the bus-bars G.