SHELL-AND-TUBE HEAT EXCHANGERS IN PROCESSES FOR THE DEHYDROGENATION OF С3-С5 HYDROCARBONS (VARIANTS)

The invention relates to a shell-and-tube counterflow heat exchanger for heating feedstock vapours in processes for the dehydrogenation of С3-С5 paraffin hydrocarbons using the heat of a contact gas exiting a dehydrogenation reactor, said heat exchanger comprising a vertical cylindrical shell (1), a heat exchange tube bundle (2) with an upper tube sheet (4) and a lower tube sheet (3), a connecting pipe (5) and a distributing chamber (6) for inputting contact gas into the upper portion of the tube side (2) of the heat exchanger (11), a collecting chamber (7) and a connecting pipe (8) for outputting cooled contact gas from the lower portion of the tube side, and also a connecting pipe (9) for inputting feedstock vapours into the shell side of the heat exchanger (11), which is divided into sections by transverse horizontal segment-type partitions (13), and a connecting pipe (10) for outputting heated feedstock vapours from the tube side of the heat exchanger. The heat exchanger is characterized in that the heat exchanger (11) comprises nozzles (12) for feeding a portion of the feedstock into the heat exchanger (11) in liquid form, said feedstock being fed into the shell side of the heat exchange tube bundle (2) and/or into the shell side of the heat exchange tube bundle (2) divided into sectors (17) that are delimited by the upper tube sheet (4) and the lower tube sheet (3) and by vertical channels (18) between the sectors (17). A variant of a shell-and-tube heat exchanger for cooling contact gas is also proposed. The technical result of the claimed invention is an increase in the productivity of plants for the dehydrogenation of С3-С5 hydrocarbons and a decrease in running costs. L'invention concerne un échangeur de chaleur à contre-courant à tubes et calandre servant à chauffer les vapeurs des matières premières pendant la déshydrogénation d'hydrocarbures paraffiniques C3-C5 par contact de gaz chaud se dégageant du réacteur de déshydrogénation qui contient une calandre cylindrique (1), un paquet de tubes échangeurs thermiques (2) avec des grilles de tubes supérieure (4) et inférieure (3), une tubulure (5) et une chambre de distribution (6) pour l'entrée du gaz de contact dans la partie supérieure de l'espace entre tubes (2) de l'échangeur de chaleur (11) ainsi qu'une chambre de collecte (7) et une tubulure (8) pour l'évacuation de gaz de contact refroidi depuis la partie inférieure de l'espace entre tube de même que des tubulures (9) pour l'introduction de