Blowing machines of VDN and DN type are produced in right and left rotation. With right rotation, the impeller rotates clockwise, when looking at the wheel from the side of the electric motor, with left rotation, counterclockwise. The snail of the VDN and DN machines is made with a turn angle from 0 ° to 270 ° every 15 °, while the ribs of the snail that interfere with the installation are cut.
Centrifugal blowers of VDN type are designed to move air and non-explosive non-aggressive gas-air mixtures with temperatures from 30 ° C to + 200 ° C, dust content up to 0.1 g / m³, free of sticky, fibrous and abrasive inclusions.
VDN and DN type blowing machines are designed to move aggressive non-explosive mixtures that do not cause accelerated corrosion of stainless steel (corrosion rate is not higher than 0.1 mm per year). The abrasiveness of the dust contained in the transported medium and its tendency to adhere should not exceed that of flue gas ash.