Blowers A blower is a rotary, positive displacement type of machine used to move gas and air and is used in a variety of methods. Rotary blowers and positive displacement blowers are just two of several types that are available. Gardner Denver offers a wide range of blowers such as regenerative, reciprocating, rotary lobe and centrifugal blowers. They are available in single or multistage versions. All Gardner Denver blowers, as different in size, performance or technology as they might be, offer reliable service for our customers' applications