Patent ID: 8540011

Claim:
A multiple shell pass shell-and-tube heat exchanger with helical baffles, comprising a shell body, an inlet for heat exchange tube bundles and an outlet for heat exchange tube bundles arranged at ends of the shell body, heat exchange tube bundles penetrating through the helical baffles and connected to two tube plates on each end of the shell body, wherein a first inner sleeve tube coaxially arranged in the shell body, a second inner sleeve tube arranged outside the first inner sleeve tube, an end of the second inner sleeve tube connected to one of the two tube plates, the first inner sleeve tube provided with a separating plate at an opposite end to an end at which the second inner sleeve tube is connected to said one of the two tube plates, whereby there forms an outer shell-pass between the shell body and the second inner sleeve tube, a middle shell-pass between the first inner sleeve tube and the second inner sleeve tube, as well as an inner shell-pass in an entire inside of the first inner sleeve tube; an outer shell-pass inlet tube and an inner shell-pass outlet tube provided to the shell body, whereby there forms a shell-pass flow passage outside said tube bundles, thus a multiple shell-pass is formed, wherein baffles in shell-passes other than the inner shell-pass are formed by splicing a plurality of helical baffles in such a transition manner that plate surfaces of individual baffles are continuous to each other along a helical direction, so baffles in shell-passes other than the inner shell-pass form a plurality of helical cycles and take the form of helical baffles with the plate surfaces thereof completely continuous so as to form complete continuous helical baffles, while the inner shell-pass is provided with a plurality of non-continuous baffles, wherein, said non-continuous baffles are in the form of non-continuously staggered fan-shaped helical baffles, which take a substantially helical form along a longitudinal axis of the heat exchanger, and are formed by staggering and at least partially overlapping a plurality of fan-shaped plates, the fan-shaped plates having holes serving to receive a heat exchange tube bundle therethrough.