In most blow tank systems the air supply to the blow tank is split into two streams.One air stream pressurizes the blow tank and may also fluidize or aerate the material in the blow tank. This air stream serves to discharge the material from the blow tank.The other air stream is fed directly into the discharge line just downstream of the blow tank. This is generally referred to as supplementary air and it provides the necessary control over the material flow in the conveying line.