HEAT EXCHANGER, METHOD OF MANUFACTURE OF FLAT COILS OF CONVECTIVE SURFACE OF HEAT EXCHANGER AND DEVICE FOR BENDING FINNED TUBES IN REALIZATION OF THIS METHOD Russian patent published in 2000 - IPC

FIELD: heat-power engineering. SUBSTANCE: method consists in making each bend of flat coils of heat exchanger on both sides from tops of bends with sections free from fins whose length is determined at preset relationship. Prior to making fins on straight tubes, positions of tops of expected bends and boundaries of sections free from fins are determined. In making the fins, ends sections of coils are left without fins for connecting them in the course of assembly and sections of preset length of both sides from top of each bend are provided; in other respects manufacture of flat coils includes no changes. Device for bending the finned tubes includes bending template additionally provided with insert made in form of part of section of circle whose radius is equal to radius of bending the load-bearing tube and central angle of sector is lesser than central angle of part of bend of load-bearing tube without fins by the amount no less than two magnitudes of helix angle of spiral fins on straight section of finned tube whose part of sector adjoining the central angle is removed; this part has form of isosceles triangle having height of 0.2 to 0.3 of bending radius of load-bearing tube. Thickness of insert ranges from one diameter of load-bearing tube to diameter of its fins; working groove of insert provided on cylindrical portion of lateral surface has width equal to diameter of loading-bearing tube and its depth is half of its width. EFFECT: modification of heat exchanger with convective heating surfaces in form coils. 4 cl, 4 dwg