Abstract: An apparatus for the synthesis of ammonia having at least two synthesis reactors in series in which two high temperature heat sink tube bundles are combined in a single shell which is close coupled to the inlet and outlet of a reactor, the second tube bundle being disposed in an interior portion of the exchanger shell inside of the first tube bundle, the first tube bundle being connected for flow from its tubes to the reactor inlet, the second tube bundle being connected for flow to its tubes from the reactor outlet.

Abstract: Apparatus is disclosed for synthesizing ammonia from an ammonia feed gas passing to an ammonia synthesis converter from a heat exchanger. The synthesis converter is close coupled through a channel to a heat exchanger and a conduit extends through the channel and is adapted to be connected to the tube side of the heat exchanger.

Abstract: A combined heat exchanger particularly suited for ammonia converter reactor effluent is described. The combined exchanger includes a first exchanger and a high temperature heat sink, such as a steam superheater, within a single exchanger shell. In a preferred embodiment, gas leaving the ammonia converter is conveyed into a single pass tube bundle which comprises the feed-effluent exchanger section and then passes through a tubesheet which separates the feed effluent exchanger section from the steam superheater section, passing over a U-tube bundle which comprises the steam superheater section in the other part of the shell. Means are provided for protecting the shell in the steam superheater section adjacent the tubesheet.