Patent ID: 8701748

Claim:
An outlet fitting for a double-pipe heat exchanger, said heat exchanger comprising a coolant tube and a process gas flow passage, said outlet fitting comprising an inlet portion, an outlet portion, and an inner element in the form of a low angle diffuser extending and expanding in cross-section between said inlet portion and said outlet portion, and a linear thermal expansion portion at the inlet portion consisting of a gap (A) between said inner element and said coolant tube to allow for thermal expansion of said coolant tube and said inner element when in the presence of heated process gas, said gap (A) effective to avoid both inner element contact with said coolant tube and formation of eddies, wherein said outlet fitting is configured to pass said process gas from said double-pipe heat exchanger to an outlet pipe, an outer element attached to said inner element at a first end of said outer element downstream of said coolant tube, said outer element further being rigidly attached to said coolant tube at a second end of said outer element.