The AirTek shop assembled collecting plate is designed for maximum structural integrity and rapping efficiency. The collecting plate is constructed of roll-formed segments (modules) which are secured with welds between the vertical modules. Upper support and lower guide tubular stiffeners are attached to the modules. The tubular edge prevents arcing that may occur where the discharge electrodes pass through collecting zones at the top and bottom of the collecting plate. These members also maintain straightness and provide structural rigidity for the collecting plate which is important for proper alignment. The upper stiffener serves an additional purpose which is to transmit the rapping energy for direct plate rapping as described below. Collecting plates can be provided in 16 or 18 gauge thicknesses, carbon steel, and other material for special applications.