Heat exchanger with stack of dimpled plates - has sealed engagement of backwardly folded edge flanges

摘要

A heat exchanger has a stack of parallel metal or plastic plates with integrally formed spacer projections on one or both faces which in contact with adjacent plates define intermediate flow spaces. At least every second plate has lateral flanges bent back in the same direction and engaging similar flanges on an adjacent plate to form alternating fluid passages at an angle, pref. 90 deg., to each other. The bent back flanges lie against spacer projections of reduced height. A method is also claimed, wherein plates made from strip are given projecting dimples on one side and their edges are then flanged in forming dies before stacking, with an intermediate sealing medium. The stack corners are held by profiled angle bars. Used for air-heating or cooling units, of simple and quick construction. Adequate edge sealing is provided without welding or adhesives. The projections help provide turbulent flow to improve heat transfer.