Abstract: In a method of making finned tubes as components of air-cooled systems or condensers, a sheet metal strip of aluminum is first shaped into a waved finned structure with plural fins in parallel relationship and arched ends for connecting the fins, thereby defining crests on opposite ends of the finned structure. A fluxing agent of cesium-aluminum tetrafluoride is applied in lines onto the crests on at least one of the ends of the finned structure. The finned structure is then placed upon a broad side of a flat steel tube coated with a zinc/aluminum alloy. The finned structure and the flat tube are subsequently joined in a brazing furnace in the presence of an inert gas at a temperature between 370° C. and 470° C. to produce a unitary structure which is then allowed to cool down at room temperature.

Abstract: In a method of making finned tubes as components of air-cooled systems or condensers, a sheet metal strip of aluminum is first shaped into a waved finned structure with plural fins in parallel relationship and arched ends for connecting the fins, thereby defining crests on opposite ends of the finned structure. A fluxing agent of cesium-aluminum tetrafluoride is applied in lines onto the crests on at least one of the ends of the finned structure. The finned structure is then placed upon a broad side of a flat steel tube coated with a zinc/aluminum alloy. The finned structure and the flat tube are subsequently joined in a brazing furnace in the presence of an inert gas at a temperature between 370° C. and 470° C. to produce a unitary structure which is then allowed to cool down at room temperature.

Abstract: In a method for joining a steel tube with an aluminum rib, a zinc-aluminum alloy layer, having an aluminum content of 0.5% by wt. to 20% by wt., is applied to the surface of the steel tube or the aluminum rib, and then a fluxing agent in the form of cesium-aluminum tetrafluoride is applied between the steel tube and the aluminum rib at room temperature before or during the mechanical contact of the aluminum rib with the steel tube. The steel tube provided with the aluminum rib is then heated to a soldering temperature of between 370° C. and 470° C. and subjected to room temperature to cool down.

Abstract: In a method for joining a steel tube with an aluminum rib, a zinc-aluminum alloy layer, having an aluminum content of 0.5% by wt. to 20% by wt., is applied to the surface of the steel tube or the aluminum rib, and then a fluxing agent in the form of cesium-aluminum tetrafluoride is applied between the steel tube and the aluminum rib at room temperature before or during the mechanical contact of the aluminum rib with the steel tube. The steel tube provided with the aluminum rib is then heated to a soldering temperature of between 370° C. and 470° C. and subjected to room temperature to cool down.

Abstract: In a heat exchanger with confronting partition walls (50) separating two fluids, extended surface for heat transfer enhancement is provided by extended surface packets (42), each comprising a multiplicity of fins (44), made integral with a common base plate (56) and a common top plate (62); packets (42) being attached to adjacent walls (50) through junction layers (68) formed by a bonding process. The partition walls (50) are typically constituted by the flat walls of oblong cross section tubes (34). In a preferred embodiment, for low temperature applications such as an air-cooled steam condenser for electric power generation plants, tubes (34) are made of steel, extended surface packets (42) are made of aluminum by extrusion, and bonding is by an organic structural adhesive.

Abstract: A cross flow heat exchanger for heat exchange between two fluids. The heat exchanger is of the type having a stack of spaced, parallel rectangular plates; a frame enclosing the plates and having generally rectangular end walls parallel to the plates and corner posts extending between corners of the end walls; and corner supports extending between the end walls and sealingly engaging respective aligned plate corners. The heat exchanger is characterized by including a plurality of leaf springs, each having a plurality of nested but individually resilient leaves elongated parallel to the corner posts and having a generally arcuate transverse cross-section providing spaced surfaces bearing respectively against a corner post and a corner support to resiliently seal the corner post to the corner support.

Abstract: A heat exchanger plate block is comprised of a stack of consecutive, spaced, parallel rectangular plates mounted within an enclosing frame. The frame has end walls parallel to the plates and corner posts extending between and joining corners of the end walls. Resilient spacers are included between the plates to render the stack of plates elastically compressible as a unit in a direction normal to the planes of the plates. Resilient corner spacers are provided to space corners of the plates from adjacent corner posts to accommodate growth of the plates due to thermal expansion in their planes. The plates of the plate stack hence float within resilient fixtures which accommodate thermal expansion parallel to and normal to the planes of the plates.

Abstract: A thin sheet heat exchanger is provided which facilitates the transfer of heat between two flowing streams of gas. The heat exchanger is formed of a packing of rectangular heat exchange plates positioned by the method of the present invention separately and parallelly to one another. The packing realizes a crossflow channel pattern for the two gas streams. The heat exchange plates which compose the bulk of the heat exchanger are, by the method of the present invention, folded at two opposite sides. The plates are stacked as prescribed by the method of this invention, and seamweld (or equivalent) sealed along the folded sides of each pair of consecutive plates, thus forming individual gas channels. Also by the method of the present invention gasket sealing surfaces and flange mounting surfaces are realized by the said folds of the said heat exchange plates.

Abstract: A fuel tank is provided for the automotive transport of a cryogenic liquid fuel which in the course of transport is being consumed by an engine or the like. The fuel tank consists essentially of two containers, one for the cryogenic fuel and the other for a secondary cryogenic liquid which is used to cool the fuel during storage when no fuel is being consumed. By the method of the invention the build up of fuel vapor pressure during storage is avoided and the vapor pressure maintained at a predetermined level. The fuel tank described herein was two distinct modes of operation, namely, the fuel storage mode and the fuel supply mode. In the fuel storage mode the cryogenic fuel is being stored for later use while the secondary fluid is being used as a heat sink for the heat absorbed by the tank from the environment.