Abstract: A reboiler in fluid communication with a fractionator column in an offshore low temperature process removing carbon dioxide from natural gas has a vessel volume. A carbon steel tubing bundle is disposed within the vessel volume. Each tube in the bundle has an outer surface with a porous granular metal layer deposited thereon. The granular metal layer comprises a pore size distribution which promotes bubble nucleation during vaporization of a nearly pure liquid carbon dioxide stream.

Abstract: A reboiler in fluid communication with a fractionator column in an offshore low temperature process removing carbon dioxide from natural gas has a vessel volume. A carbon steel tubing bundle is disposed within the vessel volume. Each tube in the bundle has an outer surface with a porous granular metal layer deposited thereon. The granular metal layer comprises a pore size distribution which promotes bubble nucleation during vaporization of a nearly pure liquid carbon dioxide stream.

Abstract: Disclosed is a heat exchanger comprising a boiling passage and cooling passage defined by opposite sides of metal walls. Layers of brazing material between the metal walls and a spacer member bond components of the heat exchanger together. It has been found that good quality brazed joints can be made by modifying the brazing thermal cycle to first employing a temperature of about 500° C. for an extended period of time and then elevating the temperature to about 590° to 600° C.

Abstract: Methods for manufacturing brazed aluminum heat exchangers involved in boiling and condensing, including a high performance nucleate boiling surface bonded with the walls of fin-less boiling passages. One method includes providing a first heat exchanger core subassembly including a first joinable end, at least one cooling and one boiling passage, and a first partial finless passage arranged at the joinable end. A second heat exchanger core subassembly is provided similar to the first including a second joinable end. The first and second heat exchanger core subassemblies are brazed. The first joinable end is affixed, preferably by welding, to the second joinable end and the first partial finless passage is affixed to a second partial finless passage to form a coupled finless passage, and thereby a heat exchanger core.

Abstract: Disclosed is a heat exchanger comprising a boiling passage and cooling passage defined by opposite sides of metal walls. Layers of brazing material between the metal walls and a spacer member bond components of the heat exchanger together. It has been found that good quality brazed joints can be made by modifying the brazing thermal cycle to first employing a temperature of about 500° C. for an extended period of time and then elevating the temperature to about 590° to 600° C.

Abstract: Disclosed is a heat exchanger comprising a boiling passage and cooling passage defined by opposite sides of metal walls. Layers of brazing material between the metal walls and a spacer member bond components of the heat exchanger together. An enhanced boiling layer (EBL) comprising metal particles bonded to each other and to a boiling side of the metal wall provides nucleate boiling pores to improve heat transfer. The EBL has a melting temperature that is higher than the melting temperature of the brazing material. Also disclosed is a process for assembling the heat exchanger.

Abstract: Disclosed is a heat exchanger comprising a boiling passage and cooling passage defined by opposite sides of metal walls. The heat exchanger is made with high strength alloys of aluminum that have improved creep resistance that maintain tensile strength and yield strength after use in this invention. Layers of brazing material between the metal walls and a spacer member bond components of the heat exchanger together. An enhanced boiling layer (EBL) comprising metal particles bonded to each other and to a boiling side of the metal wall provides nucleate boiling pores to improve heat transfer. The EBL has a melting temperature that is higher than the melting temperature of the brazing material. Also disclosed is a process for assembling the heat exchanger.

Abstract: Disclosed is a heat exchanger comprising a boiling passage and cooling passage defined by opposite sides of metal walls. Layers of brazing material between the metal walls and a spacer member bond components of the heat exchanger together. An enhanced boiling layer (EBL) comprising metal particles bonded to each other and to a boiling side of the metal wall provides nucleate boiling pores to improve heat transfer. The EBL has a melting temperature that is higher than the melting temperature of the brazing material. Also disclosed is a process for assembling the heat exchanger.

Abstract: Disclosed is a heat exchanger comprising a boiling passage and cooling passage defined by opposite sides of metal walls. Layers of brazing material between the metal walls and a spacer member bond components of the heat exchanger together. An enhanced boiling layer (EBL) comprising metal particles bonded to each other and to a boiling side of the metal wall provides nucleate boiling pores to improve heat transfer. The EBL has a melting temperature that is higher than the melting temperature of the brazing material. Also disclosed is a process for assembling the heat exchanger.

Abstract: Methods for manufacturing brazed aluminum heat exchangers involved in boiling and condensing, including a high performance nucleate boiling surface bonded with the walls of fin-less boiling passages. One method includes providing a first heat exchanger core subassembly including a first joinable end, at least one cooling and one boiling passage, and a first partial finless passage arranged at the joinable end. A second heat exchanger core subassembly is provided similar to the first including a second joinable end. The first and second heat exchanger core subassemblies are brazed. The first joinable end is affixed, preferably by welding, to the second joinable end and the first partial finless passage is affixed to a second partial finless passage to form a coupled finless passage, and thereby a heat exchanger core.

Abstract: A heat exchanger has a boiling passage and a cooling passage defined by opposite sides of metal walls. Layers of brazing material between the metal walls and a spacer member bond components of the heat exchanger together. An enhanced boiling layer (EBL) having metal particles bonded to each other and to a boiling side of the metal wall provides nucleate boiling pores to improve heat transfer. The EBL has a melting temperature that is higher than the melting temperature of the brazing material.

Abstract: The use of flow restrictors at the inlet of reactor cooling tubes significantly improves heat transfer and process performance in an acid catalyzed alkylation reaction process. Improved vaporization of the stream is achieved by equalizing the liquid distribution and the ratio of liquid and vapor entering each tube to overcome poor boiling film heat transfer. The invention relocates available pressure drop for equally subdividing the flow entering the heat exchanger into a plurality of heat exchanger inlet streams. Flow restrictors provide pressure drop at the inlets to each tube. This method and apparatus is particularly useful in contactors for the sulfuric acid catalyzed alkylation of olefinic and isoparaffinic hydrocarbons.

Abstract: A method and apparatus for indirectly heating a mixed phase stream by contact with a boiling surface located on the inside of the plurality of heat exchange tubes. Improved vaporization of the stream is achieved by equalizing the liquid distribution and the ratio of liquid and vapor entering each tube to overcome poor boiling film heat transfer. The invention uses a means for subdividing the flow entering the heat exchanger into a plurality of streams with each of the divided streams discharging directly into a heat exchange tube. The means for dividing the stream can include baffle arrangements or plugs providing pressure drop at the inlets to the tubes. This method and apparatus is particularly useful in contactors for the sulfuric acid catalyzed alkylation of hydrocarbons.

Abstract: A method and apparatus for indirectly heating a mixed phase stream by contact with a boiling surface located on the inside of the plurality of heat exchange tubes. Improved vaporization of the stream is achieved by equalizing the liquid distribution and the ratio of liquid and vapor entering each tube to overcome poor boiling film heat transfer. The invention uses a means for subdividing the flow entering the heat exchanger into a plurality of streams with each of the divided streams discharging directly into a heat exchange tube. The means for dividing the stream can include baffle arrangements or plugs providing pressure drop at the inlets to the tubes. This method and apparatus is particularly useful in contactors for the sulfuric acid catalyzed alkylation of hydrocarbons.

Abstract: A process for the reforming of hydrocarbons is improved by the use of an enhanced nucleate boiling surface in a selected portion of the feed effluent heat exchanger. In a vertical type heat exchanger where the reforming feedstream enters at a lower end of the heat exchanger and is at least partially vaporized in the heat exchanger by contact with a reforming effluent stream that enters an upper end of the heat exchanger and is at least partially condensed therein, an enhanced nucleate boiling surface is formed on the heat exchange surface that is in contact with the entering liquid phase portion of the stream feed. The enhanced nucleate boiling surface increases the amount of condensing that takes place on the opposite side of the heat exchange surface in a boiling-condensing zone.