Abstract: A method of connecting a pipe to a pressure conveying element, especially a pipe plate, a pressure container, and a collector, according to which the pressure conveying element is within the region of its intended connection with the pipe provided with lips. After the pipe provided on its inside and outside with a lip has been introduced into the pressure conveying element, the pipe is at its outer lip connected to the lip of the element by a complete through weld. Subsequently a centering bushing is introduced into the pipe and is clamped therein so that the outer surface of the centering bushing together with the inner surface of a bore in the conveying element--which bore is substantially coaxially arranged with regard to the pipe--forms a flat annular trough, whereupon the space between the outside surface of the centering bushing and the inner surface of the trough is filled with welding material.

Abstract: A multi-start involute regenerator matrix disk and method for assembling the same, the matrix disk including a hub mandrel with a plurality of matrix elements, each preferably including a matrix strip and a separator strip, in series orientation, endwise abutment against the hub mandrel and mechanically secured to the hub mandrel by a pair of annular pinch rings pressed into the opposite side edges of the matrix elements with the pinch rings positioned to encircle the hub mandrel radially outward thereof whereby to effect wedging of portions of the matrix elements against the outer peripheral surface of the hub mandrel, the matrix elements spirally encircling the hub mandrel in an involute configuration and bonded together to form a rigid elastic matrix structure.

Abstract: An improved method of making a high heat transfer surface composed of metal mesh is described. The surface comprises multiple layers of wire mesh, stacked and laminated together by silver brazing. Advance in the state-of the-art is the novel manufacturing process designed to maximize heat transfer. Prior knowledge on manufacture of porous metal laminates has principally had as its purpose the filtration of particulate or control of hydraulic boundry-layer and made use of sintering techniques to solidify the elements. This invention optimizes the use of materials and process to accomplish maximum heat transfer.

Abstract: A method including the step of applying braze alloy in sheet-like form to a part made of a brazeable parent metal. Pressure is exerted to place the braze alloy in intimately contacting relation to the part. For a predetermined period of time, while the exerted pressure is maintained, heat is applied at a temperature value which is just below the melting point of the braze alloy. Diffusion bonding occurs and, in accordance with an optional practice of the invention, a catalyst may be introduced which at a temperature below the applied temperature liquifies and speeds up the diffusion process.

Abstract: A method for brazing nickel to aluminum in a vacuum and product produced thereby. The outer surface of the aluminum member to which the nickel member is to be brazed is precoated with a layer containing silicon and magnesium. The nickel and aluminum members are placed together in an oven at reduced pressures and heated to a temperature of approximately 593.degree.C cracking the oxide coating upon the aluminum sheet. The presence of magnesium and silicon in the surface of the aluminum sheets makes possible an excellent braze with a large filleted area. The process may be further adapted for brazing other metal components to aluminum by first precoating the component with nickel.

Abstract: A heat exchanger core includes a communicating set of metallic tubular elements, preferably aluminum, for carrying a primary fluid and a matrix of rounded metallic elements. The matrix elements are metallurgically bonded to one another and to the tubular elements. This arrangement of the matrix creates a multiplicity of communicating interstices which serve as passageways for the secondary fluid. The surface of the rounded elements constitutes the major area exposed to the secondary fluid flow. The rounded elements are metallurgically bonded by preferably a brazing technique. Relatively small particles of low melting temperature alloy, preferably aluminum, are dispersed throughout a stacked arrangement of relatively larger rounded elements, preferably of aluminum of a higher melting temperature. In one brazing method, an assembly of tubes, large rounded elements and smaller particles are brazed in a vacuum brazing oven. At the temperature of the oven, the smaller particles melt but the larger elements do not.

Abstract: Tubes of thermoplastic material having an elastic memory are assembled with radiating plates of a heat exchanger by:Longitudinally drawing the tubes at a first temperature in the neighborhood of the softening point of said material so as to reduce their transverse dimensions;Cooling said tubes to the ordinary temperature while maintaining the drawing force;Putting the tubes and the plates in their desired relative positions;Bringing the assembly to said first temperature so that the tubes can resume their initial transverse dimensions.

Abstract: Apparatus for affixing surface enlarging, transversally corrugated metal strips to elongate metal basic profiles which are advanced in the direction of their longitudinal axes whilst simultaneously being joined by a joining compound to the wave crests on one side of the corrugated metal strips. The apparatus provides a furnace for heating the basic profile to a temperature which exceeds the melting point of the joining compound, a device for advancing the metal strip longitudinally externally of the path of the basic profile while applying the joining compound to the crests and solidifying a suitable portion of the compound at respective crests by conducting heat away from the compound through the strip to material.

Abstract: A series of thin-walled, heat exchange tubes are soldered to return bends of similar materials so as to complete a flow path through the tube bundle by a process which comprises press-fitting the return bends to the tubes, preheating the return bends and portions of the tube adjacent the bends to a temperature, the average of which is approximately the soldering temperature, soaking the preheated portion in a liquid which will equalize the temperature of the various preheated portions, and ultrasonically soldering the return bends to the tubes.

Abstract: The process is characterized in that hot gas are blown at right angle with the front face of the parts to be brazed into the contiguous areas of an enclosure. The speed of the hot gas in a first area is regulated in order to ensure pre-heating, the speed in a second area is regulated in order to increase the temperature to the brazing temperature and the speed in a third area is regulated in order to ensure at least a partial cooling of the parts before they are withdrawn from the enclosure.