FansCentrifugal blowersBlowersPositive Displacement 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


Centrifugal Technology is a constant pressure variable flow aerodynamic compression of air or gas where flow is proportional to power consumption. The centrifugal technology achieves a pressure rise by adding kinetic-energy/velocity to a continuous flow of air through the rotor or impeller. This kinetic energy is then converted to an increase in static pressure by slowing the flow through a diffuser. This technology is used in many different blower and compressor products such as; centrifugal compressors and fans as well as centrifugal multistage blowers to name a few.

Oil Free

Oil-free and oil-less technology are used in a variety of applications across the globe. Hospitals, pharmaceuticals, the food industry, among many others depend on Gardner Denver to provide the cleanest, oil-free air for their systems and processes.

In a lubricated machine oil is used to seal, lubricate and cool, however this then leaves high oil content in the compressed air that has to be removed. Oil free compressor, or oil less compressors, use an alternative medium such as water to seal, lubricate and cool, or compression takes place in multiple stages, the compressor then delivers the highest quality air without the need for separation and filtration. The types of technologies used in oil free compressors include, Water Injected compressors, two stage dry screws, single or two stage oil free pistons or centrifugal compressors.

Gardner Denver offers a wide variety of oil-free and oil-less technologies including a two stage dry screw capable of pressures over 150 psig and a water injected single screw compression element that provides a system package 100% free of oil, completely eliminating the possibility of oil contaminating the system. This technology makes Gardner Denver an industry leader in providing oil free compressed air. In an oil-free machine, the air is compressed entirely through the action of the screws, without the assistance of an oil seal. They usually have lower maximum discharge pressure capability as a result. However, multi-stage oil-free machines, the air is compressed by several sets of screws. Oil-free machines are used in applications where entrained oil carry-over is not acceptable.

Positive Displacement

Positive displacement compressors take advantage of positive displacement technology; which causes movement by trapping a fixed amount of air then forcing (displacing) that trapped volume into the discharge pipe. Positive displacement technology can be further classified according to the mechanism used to move air.


Radial fans, also known as radial blowers or radial compressors, are a reliable, compact and safe technology for vacuum and pressure. They come as single- stage and multi-stage versions. Typical applications include packaging and paper handling.

Operating principle: as the impeller rotates, the air in the blade chamber of the impeller is centrifugally moved outward and exits at the edge of the impeller. This creates negative pressure at the hub of the impeller causing air to be sucked in. The incoming air is deflected from an axial into a radial direction as it enters the blade chambers. Due to the high speed of the impeller, the air flows outward into the spiral housing. At this point the velocity is reduced and part of the energy is transformed into compression energy. The air then exits through the outlet of the blower.

Side Channel

Side channel blowers / side channel pumps can be used as vacuum pumps or compressors and are a highly efficient dry running technology for numerous applications. These contact free machines are virtually maintenance-free and can operate up to 40,000 hours without being serviced. Noise levels are extremely low which makes them a favorite for noise-sensitive applications.

The impellers are mounted directly on the motor shaft for contact free compression. Maximum operational reliability, even at high differential pressures, is ensured by the arrangement of the bearings outside the compression chamber. The gas is taken in through the inlet. As it enters the side channel, the rotating impeller imparts velocity to the gas in the direction of rotation. Centrifugal force in the impeller blades accelerates the gas outward and the pressure increases. Every rotation adds kinetic energy, resulting in further increase of pressure along the side channel. The side channel narrows at the rotor, sweeping the gas off the impeller blades and discharging it through the outlet silencer where it exits the pump.