SHELL AND TUBE HEAT EXCHANGER Russian patent published in 2022 - IPC F28D7/12 B01J19/00 C01C1/04 F28D21/00 

FIELD: heat engineering.

SUBSTANCE: claim describes a shell and tube apparatus (1) including: an external casing (2), a first tube bundle (3) and a second tube bundle (4) extending coaxially with each other; a first internal casing (5) and a second internal casing (6); wherein the first internal casing surrounds the first tube bundle and is located between said two tube bundles; the second internal casing surrounds the second tube bundle and is located in the space between the second tube bundle and the external casing (2); the first tube bundle (3) works as a steam generator; the second tube bundle (4) works as a preheating apparatus; the coaxial inner casings (5, 6) form a passage for the counterflow of the hot fluid passing in the inter-tube space.

EFFECT: reduced complexity of the heat recovery section including a preheating apparatus and a steam generator, providing at the same time the same flexibility as with two separate apparatuses.

15 cl, 11 dwg