QLDG/QLDH – Steel Coils
The heat exchanger or steam coil is used to heat air for drying purposes with the heat energy supplied as steam. The profiled plate fin with zigzag tubes is designed to accomplish effective and economical heat transfer between the internal medium of steam and the drying air. The plate fin body of the heat exchanger consists of tubes of copper or copper-nickel that have been expanded mechanically against plate fins of aluminium. Each heat exchanger plate fin is in one piece, without slits or joints, to prevent dust particles and fibres from sticking to the plate body. The casing or frame is made of hot-dip galvanized steel sheet and is provided with lifting lugs in each corner and attachments for a mesh filter. The manifold pipes of the heat exchanger are exposed inside the frame to enable the removal of fibres. The manifold pipe on the entry side (steam) is made of steel and coated with a corrosion-protective paint. The manifold pipe on the exit side (condensate) is made of copper-nickel, and the condensate coupling is made of boiler steel coated with a corrosion-protective paint.