| 摘要 |
1,056,582. Tubular heat exchangers. E. I. DU FONT DE NEMOURS & CO. Aug. 10, 1965 [Aug. 12, 1964; Nov. 2, 1964 (2)], No. 34149/65. Heading F4S. A heat exchanger intended for use where one or other of the heat exchanging fluids is corrosive, comprises a casing 11 containing a tube bundle the tubes 21 of which are spaced apart by spirally wound tapes 25 (see Fig. 6, not shown) which also act as baffles to determine the pattern of fluid flow over the tubes (see Figs. 4, 7 and 9, not shown). The tubes and preferably also the tapes are made of a synthetic plastics material. The casing 11 is preferably of stainless steel. Several methods of positioning and bonding the tapes on to the tubes are described, the tapes being positioned according to the required fluid flow pattern. The tubes are preferably made of a fluorocarbon polymeric material. The tapes may also be made of polymeric materials but alternatively may be made from a cellulose, metal or textile material. The dimensions of the tapes are from # to ¢ inch wide and about 0À010 inch thick; and the tubes are from 0À08 to 0À25 inch outside diameter with a wall thickness from 5% to 15% of this diameter. In the heat exchanger shown the tube ends are gathered and bonded together into a honeycomb structure 22 which is encircled by a thin sheath 23 made of a material similar to the tubes. The sheath is bonded to the tubes and to a surrounding sleeve 24 which is made of a corrosion resistant alloy such as ceramic, phenolic or copolymeric fluorocarbon having a melting point higher than that of the tubes. |
