GB669975A - Improvements in heaters for heating liquids in tanks, for heating ovens, and for like purposes - Google Patents

Abstract

669,975. Heaters for liquid baths, ovens, &c. SKINNER, A. J. Nov. 1, 1949 [May 5, 1947], No. 12032/47. Class 51 (i). [Also in Group XIII] A heater for liquids, ovens, &c., or for melting metals comprises a refractory tube 10 containing a gas burner 15 and surrounded by another tube 12, combustion taking place in the inner tube and the combustion gases flowing from that tube, in one form (Fig. 1), through an end opening or side openings into the annular space 13 between the two tubes, a deflector 11 or deflectors being provided on the outer or inner surface of theinner tube 10. In other forms, the combustion gases flow through an annular space between the outer tube 12 and a second inner refractory tube 10b, Fig. 3, or through an annular space or spaces between a further pair or pairs of tubes 10a, 26a and 10b, 26b, Fig. 10, and a baffle 11 or baffles are provided on the outer surface of the additional inner tube or tubes 10a, 10b. Alternatively, the combustion gases flow, as in Fig. 11, through the annular spaces between the first pair of tubes 10, 12 and between further pairs of tubes 12a and 24, 25. The baffle 11 may be helical and of constant pitch, or of increasing pitch in the direction of flow of the gases, as shown in Fig. 1. In Fig. 5, the refractory tube comprises a series of refractory rings 21 with projections 21a, 21b, 21c arranged spirally. The rings may have on their upper and lower surfaces complementary annular projections and recesses which may have inclined surfaces so that the distance apart of the rings can be varied by relative rotation. The rings may be threaded on to a refractory tube, or may be arranged so that hot gases can escape between them. Alternatively, the refractory tube may be perforated or made of porous material. In the forms shown in Figs. 10 and 11, the ends of the inner tubes 10a, 10b and 24, 25 are closed.