HEAT EXCHANGER AND METHOD OF HEAT EXCHANGE Russian patent published in 2001 - IPC

FIELD: heat exchangers. SUBSTANCE: heat exchanger has zone for delivery of process fluid and zone for discharge of this fluid which are separated from heat exchange zone by means of boundary units such as tube sheets or collector tubes. Many heat-exchange process fluid tubes tub through heat-exchange zone from one of boundary units; it is slidably engageable with sealing tubes at other boundary unit; sealing tubes are secured to other boundary unit. Provision is made for construction in one tube for forming low-pressure area downward from restriction in way of flow followed by expansion area and one or several passages through wall of this tube for connection of low- pressure area with external side of inner tube. Passages are located inside overllaping area of sealing tube and heat-exchange tube to ensure flow of leakage from heat-exchange zone to low- pressure area through overlapping area and passages. Proposed method includes processing of process fluid, viz.: delivery of process fluid to process fluid delivery zone, passing the process fluid from delivery zone through many heat-exchange tubes running through heat-exchange zone, subjecting the process fluid to heat exchange with heat-transfer agent in heat-exchange zone, passing the process fluid from heat-exchange tubes to process fluid discharge zone separated from heat-exchange zone by second boundary unit. Process fluid flowing from discharge zone is subjected to special treatment and resulting fluid is passed through heat- exchange zone as heat-transfer agent; heat-exchange tubes are secured to one of boundary units. EFFECT: increased thermal expansion between tubes and tube sheet. 10 cl, 6 dwg