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US 6,960,333 B2Granted
High performance heat exchangers
AssigneeRohm and Haas Company
InventorsPaul Joseph Blanda, Jr., Michael Stanley DeCourcy
Life of this patent
Estimating the term…
Abstract
Disclosed are means for improving the service-life of indirect tubesheet type heat exchangers used in chemical reactors, particularly those exposed to reducing, nitridizing and/or carburizing environments. Such means include the use of certain ferrules within the heat exchange tubes and/or weld types used in construction of these heat exchangers.
Claims11
A process for preparing hydrogen cyanide comprising the steps of:
- feeding reaction gas to a reactor, the reaction gas comprising hydrocarbon, ammonia and optionally an oxygen-containing gas;
- reacting the reaction gas in the presence of a catalyst to give product gas;
- cooling the product gas in a heat exchange apparatus comprising (a) a shell having an entry tubesheet and an exit tubesheet, each tubesheet having a plurality of holes, wherein the shell has at least one inlet and one outlet for heat exchange medium;
- (b) a plurality of tubes disposed within the shell wherein an entry end of each tube is affixed to the entry tubesheet and an exit end of each tube is affixed to the exit tubesheet such that an axis of the tube and an axis of an entry and exit tubesheet hole are coincident;
- and (c) a plurality of ferrules, each ferrule having an entry end and an exit end extending through an entry tubesheet hole into a tube wherein the exit end extends below the entry tubesheet, the ferrule comprising silicon nitride;
- and recovering hydrogen cyanide from the cooled product gas.
3 more elements
A process for cooling a reducing, carburizing or nitridizing gas;
- said process comprising cooling said gas in a heat exchange apparatus comprising (a) a shell having an entry tubesheet and an exit tubesheet, each tubesheet having a plurality of holes, wherein the shell has at least one inlet and one outlet for heat exchange medium;
- (b) a plurality of tubes disposed within the shell wherein an entry end of each tube is affixed to the entry tubesheet and an exit end of each tube is affixed to the exit tubesheet such that an axis of the tube and an axis of an entry and exit tubesheet hole are coincident;
- and (c) a plurality of ferrules, each ferrule having an entry end and an exit end extending through an entry tubesheet hole into a tube wherein the exit end extends below the entry tubesheet, the ferrule comprising silicon nitride.
Dependencies are inferred from the claim text.