GB538798A - Improvements in or relating to cooling apparatus - Google Patents

Abstract

538,798. Refrigerating; tubular apparatus. STEVENS, A. H. (Pfaudler Co.). Feb. 12, 1940, No. 2684. [Classes 29 and 64 (iii) ] A refrigerating evaporator comprises a tubular or other conduit of uniform external size fitted with internal baffles providing a refrigerant passage increasing towards the outlet end, the refrigerant being circulated at high speed and with a whirling motion produced by the baffles. The evaporator may be of the type immersed in liquid in a vat 12, Fig. 3, or of the type in which milk &c. is allowed to spread over the surfaces of an upright bank of tubes, Fig. 9. The immersion type. comprises a group of U-tubes connected at one end to a header 20 of elliptical shape and detachably mounted so as to be removable through-an end manhole (not shown), the U preferably being formed by welding together bent ends of straight tubes to form a point offering small resistance to axial flow of the vat liquid circulated by an impeller 70. The header is supported by the inlet and outlet pipes 55, 56 welded to an inner plate 58. positioned by a divided external plate 59 and bolts, and the ends of the tubes are connected by rods 50 and supported from the side of the vat by a post 51 of narrow section in the direction of length of the tubes to permit of expansion. The tubes are connected to the header in the manner shown in the developed view, Fig. 7, so that their cut-away ends form baffles to provide sinuous flow. , The internal baffles comprise cores 81 and spiral wire 85 of increasing pitch for the first few tubes, the cores if desired being of diminishing size, and helical wires or spirally twisted strips for further tubes. Byepass openings 93, 95 &c. may be formed in the ends of the tubes inside the header to alter the flow. and may be uniform size or of different sizes. In the surface milk cooler, Fig. 9, the refrigerant may be admitted at 140 near the top and rise to the top tube and then be led by a conduit 145 to a lower tube and flow downwards to the outlet 148. The inlet valve 155 may be controlled by a thermal element 156 on the outlet conduit.