GB920401A - Improvements in air cooled heat exchangers - Google Patents

Abstract

920,401. Air cooled heat exchangers. HAPPEL G.m.b.H., [trading as GEA LUFTKUHLERGESELLSCHAFT HAPPEL G.m.b.H., K.G.]. Aug. 18, 1961, No. 29917/61. Class 64(3). In an air-cooled heat exchanger comprising at least two tubular heat exchange units 1, 1a inclined to each other in a gable formation and supported above ground level on a rigid framework of girders and a fan 4 positioned below the heat exchanger units to provide an upward flow of cooling air, the driving parts of the fan are situated on the pressure side of the fan blades and the fan is mounted on girders disposed with their greatest cross-sectional dimensions upright. In Figs. 1 and 3, a plurality of condenser sub-units 1, 1a are arranged either side of a steam distributer pipe 2 and each sub-unit is connected to the distributer pipe via a distributer chamber 7. A condensate collection chamber 8 at the bottom of each sub unit is connected to the condensate collection pipes 3, 3a and to the air suction pipes 11, 11a. The heat exchange sub-units 1, 1a are fastened on to the sub-unit bearers 12, 12a joined at the apex of the gable by a cross piece 13, and nesting at their lower ends on tubular longitudinal bearers 14, 14a mounted on the vertical supports 15, 15a. The bearers 14, 14a are connected by cross members 16 which project laterally beyond the bearers 14, 14a and in conjunction with the longitudinal members 18, 18a arranged in parallel with the bearers 14, 14a, serve for mounting access platforms 19, 19a and handrails 24. Similarly mounted access platforms are provided at the ends of the installation. The fan-mounting girders comprise two horizontally spaced parallel trapezoidal lattice frames 26 braced by vertical struts 26c and connected by horizontal struts 26d. The frames 26 are mounted on to longitudinal bearers 27 welded to the bearers 12, 12a. The fan-driving motor 5 disposed offset from the shaft of the fan is mounted between the frame 26 in the central span. The circle of rotation of the fan 4 is bounded by a cylindrical duct 29 which is widened out at either end by conical sections 29a, 29b to approximate to a Venturi. A protective grill 30 is flanged on to the bottom conical section 29f by a collar 31. An annular pipe 32 fixed to the collar carries equispaced inwardly directed spraying nozzles 34 for humidifying the suction air. In a modification, Fig. 10, the motor and fan are mounted between a pair of rectangular lattice frames 36 which form a longitudinal bridge down the centre of the heat exchanger and are mounted on the cross members 16. A walkable platform is provided between these lattice frames. The hub of the fan 4 has a streamline cowling 4a. The cylindrical air ducting extends to the level of the horizontal cross members 16 and is connected thereto. A protective grating 38 is fastened to the bottom of the conical portion 29b of the air duct. An annular pipe 39 surrounds this conical section and horizontal pipes 40 extending into the air duct are provided with nozzles 41 directed upwardly to the fan axis. The supporting framework of the heat exchanger is strengthened by cross bracings.