摘要:
A tubular exchanger for operations under conditions of heat and pressure comprising a set of tubes made of ferritic steel having the following composition:C .ltoreq. 0.010%,Cr 25 to 30%,Mo
摘要:
A tube-type vessel, such as a heat exchanger, has tubes that extend away from a tubesheet provided with holes which axially align with the tubes and open into the tube interiors. The diameter of each hole in the tubesheet is less than the outside diameter of the tube with which it aligns, but is greater than the inside diameter of the tube, thereby producing an offset between the inside surface of the tube and the surface of the hole. The tubes are attached to the tubesheet by welds, and each weld forms a fillet between exterior surface of its tube and the back face of the tubesheet and further forms a smooth beveled transition between the inside surface of the tube and the surface of the hole. The fillets eliminate the crevices that surround the tubes in conventional structures, and as a consequence no material will build up around the tubes and collapse them. To unite the tubes with the tubesheet, the latter at each hole is provided with a socket into which the end of a tube is fitted. The socket serves to precisely locate the tube with respect to the hole. Then the hole is welded autogenously to the tubesheet from within the hole. The weld completely penetrates the portion of the tube within the socket and further extends into the tubesheet, both radially beyond the circular side wall of the socket and axially beyond the base of the socket. In so doing, the fillet and smooth beveled transition are produced at the exterior and interior surfaces of the tube, respectively.
摘要:
A new and improved automotive heat exchanger and a method of assembling tubes in a header of a heat exchanger comprising, shaping the ends of non-circular cross section tubes into a substantially circular cross section, forming collared openings of substantially circular cross section in a header wall, inserting the tube ends into the openings, welding and bonding the tubes to the header wall.
摘要:
A heat exchanger core assembly having an improved tube-to-header joint construction wherein each individual tube end portion is preformed into a diamond-shaped configuration and each mating header plate is likewise preformed to include a plurality of diamond-shaped openings adaptable for receiving the corresponding diamond-shaped tube ends therethrough. Each tube member includes a body portion, a diamond-shaped end portion located at each opposite end thereof, and a gradual transition section which extends from each opposite end of the tube body portion to the respective diamond-shaped tube end portions. When mated together, each tube-to-header joint is bonded together such as by soldering or brazing. Each of the diamond-shaped openings in the mating header plates may also include an increased flange area extending at least partially therearound to improve the structural integrity and strength of the soldered or brazed joint between the tube end portions and the mating header plates.
摘要:
Assembly device of tubes of low carbon ferritic stainless steel having 17 to 18.5% by weight of chromium on a tube-plate of carbon steel. It includes a first overlay of low carbon austenitic stainless steel having 11.50 to 14% by weight of nickel and 22 to 25% by weight of chromium on the surface of the tube-plate opposite the plurality of tubes, a second overlay on the first of low carbon austenitic stainless steel having 10 to 12% by weight of nickel and 19 to 23% by weight of chromium extending beyond the upper level of the ends of the tubes, and weld beads with or without filling metal around these ends between these ends and the stainless steel of the second overlay.
摘要:
A passage is provided in a heat exchanger water compartment to permit expansion of a tube following its introduction into the bottom of the compartment. The heat exchanger is constructed so that a parameter K.sub.1 is in the range of 1.2 to 8. This parameter is equal to the length of the surface in contact between the tube and the passage multiplied by the ratio of the thickness of the bottom to the thickness of the tube wall, and the ratio of the tensile strength of the bottom material to the tensile strength of the tube material.
摘要:
Process for permanently fastening the end or ends of at least one rod, made at least partially of a thermoplastic material and having at least one continuous cavity, in at least one opening of a support plate. The opening surrounds at least one rod, with each rod - in order to be fastened - positioned in its designated opening in the support plate. Each rod cavity exhibits a hydraulic diameter which corresponds to at least 10% of the minimum outside cross-sectional dimension of the rod, and the rod walls may exhibit pores which take up a maximum of 20% of the wall volume. The rods are positioned with the support plate in such a manner that the ends are essentially arranged vertically upward and the support plate essentially horizontally, and, subsequently, sufficient heat is applied to the rod ends from above, so that the rod ends will soften at least to some extent and the outside walls of the rod ends will expand to such an extent that they touch the wall surfaces of the support plate openings and adhere or fuse to thereto. Also disclosed is a heat exchanger which may be formed by this process.
摘要:
Assembly of tubes in low carbon ferritic stainless steel having 17 to 18.5% by weight of chromium on a tube-plate of carbon steel. It includes at least one overlay of low carbon steel on the surface of the tube-plate opposite the plurality of tubes, of such thickness that the ends of the tubes are located at an intermediate level of the overlay, and weld beads between the ends of the tubes and the overlay.