A blower refers to a fan with an outlet pressure of 30-200kPa under design conditions. Based on different structures and working principles, blowers are generally divided into positive displacement blowers and turbomachinery blowers.

Positive displacement blowers compress and transport gas by changing the gas volume, with roots blowers and screw blowers being common types. Turbomachinery blowers compress and transport gas through rotating blades, mainly including two major categories: centrifugal blowers and axial flow blowers.

Currently, the most widely used types are roots blowers and centrifugal blowers, which are mainly applied in various fields such as the cement industry, sewage treatment industry, medical industry, power industry, and aquaculture.

A centrifugal blower is generally composed of an impeller, volute, motor, frequency converter, bearings, control system, and cabinet, among which the impeller, motor, and bearings are the core components. Compared with roots blowers, centrifugal blowers have a wider range of options in terms of pressure rise and flow parameters, and feature high efficiency, low noise, and stable operation. Their application scope covers traditional heavy industry fields such as petrochemical engineering, metal smelting, thermal power generation, and cement manufacturing, as well as new environmental protection fields such as sewage treatment, waste heat recovery, and desulfurization and denitrification. Centrifugal blowers mainly include traditional single-stage centrifugal blowers, multi-stage centrifugal blowers, as well as air-bearing centrifugal blowers and magnetic-bearing centrifugal blowers that represent the advanced technological direction of the industry.

Traditional single-stage and multi-stage centrifugal blowers have complex structures, high failure rates, heavy post-maintenance workloads, and are prone to leakage of lubricating oil and grease, causing pollution to the environment and compressed air.

Magnetic-bearing centrifugal blowers adopt magnetic bearing technology, eliminating the need for the complex gearbox and oil-lubricated bearings that are essential for traditional blowers. This achieves oil-free lubrication and no mechanical maintenance, effectively reducing the user's post-maintenance costs. The control system of magnetic bearings is relatively complex, and the product has high technical content and a long service life.

Air bearings use air as a lubricant. Air, as a lubricant, has the characteristic of low viscosity and is chemically more stable than liquids over a wide temperature range. Air bearings do not require spindle sealing, and eliminate the equipment needed for storing, heating, cooling, injecting, and extracting liquid lubricants. This simplifies the bearing structure, reduces bearing costs, and offers advantages such as reduced vibration, lower noise, and keeping the compressed medium free from contamination. In recent years, air bearings have been widely used in the blower industry. Air-bearing centrifugal blowers use air bearings, direct-drive technology, high-efficiency impellers, and high-speed motors, resulting in no additional friction, almost no vibration, no need for special installation foundations, and simple and flexible installation and arrangement.

Of course, compared with traditional centrifugal blowers, air-bearing centrifugal blowers and magnetic-bearing centrifugal blowers at the current stage both have the characteristics of high purchase prices and high maintenance and repair costs. In addition, further in-depth research is needed in terms of performance reliability and application in segmented fields.