摘要:
868,348. Tubular heat exchangers. SVENSKA FLAKTFABRIKEN A. B. Oct. 6, 1959 [Jan. 28, 1959], No. 33834/59, Class 64(3) In a heat exchanger comprising a bank of pipe coils 2 arranged within a casing 1 through which air is caused to flow and wherein each coil consists of a number of tubes 3 interconnected in series by bends 4 located outside the casing, bleed pipes 8 interconnect certain of the bends 4 and this arrangement is said to prevent freezing up and consequent bursting of the tubes, when for example the air is being heated, by permitting the heating fluid to pass between relatively warm and cold zones of the tube bank. The pipes 8 may interconnect tube bends at the air entry end of the pipe or, as indicated at 8 1 may interconnect other tube bends in the bank. Each tube bend may consist of two tube parts interconnected by a member adapted also to receive the end of a pipe 8 or 8 1 .
摘要:
847,438. Valves. SVENSKA FLAKTFABRIKEN A.B. April 29, 1958 [April 30, 1957], No. 13573/58. Class 135. In a ventilating system the flow of air between ducts 2 and 5 is controlled by a channelshaped valve member 6 forming a movable wall portion of the duct 2 and operated by the static pressure of the air in that duct acting against loading springs 12 to vary the area of narrow flow passages 7. To avoid eddies in the flow and thus reduce noise in the normal working position, the length of each of the passages 7 is greater than five times their hydraulic diameter (defined as four times the cross sectional-area divided by the perimeter), and the Reynolds Number does not exceed 2,000 at the maximum speed of flow.