Heat exchanger incorporating nitriding-resistant material
AssigneeUhde GmbH
InventorsHans-Dieter Marsch, Hans-Gunther Briecke
Life of this patent
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Abstract
In a heat exchanger for heat transfer between ammonia converter effluent recycle gases and water, a plurality of U-shaped tubes have their inlet and outlet ends connected to a tubesheet which divides the interior of a shell into a pressure chamber and a heat exchange chamber containing the tubes. The pressure chamber is divided into an inlet chamber and an outlet chamber with the cooled recycle gases flowing into the outlet chamber and cooling the inlet chamber. The tubes are formed of ferritic steel and are welded to the tubesheet. A tubular cladding of nitriding-resistant material extends through the tubesheet at the inlets to the tubes and spaces the recycle gases from the tubes at the inlet ends.
Claims11
A heat exchanger for heat transfer such as between ammonia converter effluent recycle gas and water comprising a shell forming a closed space, a tubesheet secured within said shell and dividing the space therein into a pressure chamber on one side of said tubesheet and a heat exchange chamber on the other side of said tubesheet, a plurality of heat exchange tubes located within said heat exchange chamber and each of said tubes having an inlet end and an outlet end secured to said tubesheet for carrying a heat exchange medium through said heat exchange chamber, the inlet and outlet ends of said tubes are welded to said tubesheet and arranged to convey the heat exchange medium medium through said heat exchange chamber, wall means located within said pressure chamber and dividing said pressure chamber into an inlet chamber for flowing the heat exchange medium into the inlet ends of said tubes and an outlet chamber for receiving the cooled heat exchange medium from the outlet ends of said tubes with said outlet chamber at least partly enclosing said inlet chamber so that the cooled heat exchange medium cools said inlet chamber, said tubesheet having a pressure chamber side and a heat exchange chamber side and a plurality of tubesheet holes extending from the pressure chamber side to the heat exchange chamber side, said tubes are formed of ferritic steel, said tube sheet having the inlet end of said tube connected thereto for receiving the heat exchange medium from said inlet chamber, and a tubular cladding of nitriding-resistant material extending through said tubesheet holes into the inlet ends of said tubes from the pressure chamber side of said tubesheet to at least the heat exchange chamber side, said inlet chamber is spaced from the pressure chamber side of said tubesheet by a portion of said outlet chamber and said wall means forming said inlet chamber comprising a wall section spaced from said tubesheet and having holes therethrough aligned with said holes in said tubesheet.
Dependencies are inferred from the claim text.