A typical blower can look quite similar to an air compressor. However, these devices are fundamentally different.
Think of a blower as a fan that blasts large quantities of air continuously from one location to another, at faster speeds than a typical house fan. Used for heating, cooling, ventilating, and transporting, blowers produce lots of air in order to create additional airflow, but at a relatively low pressure compared with an air compressor.
By contrast, an air compressor squeezes more air into a smaller space at higher pressure intensity than an air blower. It actually makes the air denser. The purpose is to provide intense pressure to enable tools and applications to work with powerful force.
Screw compressors also enable you to obtain clean, dry air by incorporating dryers into the workgroup.
You can also get additional storage capacity with scroll compressors, which allow you to install smaller screw compressors in the tank.
You can also get a screw compressor to fit the size of your facility, saving you even more costs.
So how does a blower work? At the start, air gets sucked into the suction side of the device. The rotors and impellers rotate. The air then gets pressurized and released.
Depending on how they move the air, blowers can be classified as either positive displacement or centrifugal.
Centrifugal: Air enters the center of a spinning impeller and divides between the impeller's blades. As the impeller turns, it accelerates the air outwards using centrifugal force. In the surrounding blower housing, this high-velocity air diffuses and slows to create pressure. Because centrifugal machines operate with pressure and flow rate as dependent variables, centrifugal blowers operate best as base load machines or in applications with constant pressure.
Rotary Lobe Blowers : Rotary lobe blowers consist of two rotors spinning in opposite directions. The blower sucks in air, and the lobes spin the air around before pushing the air out. They produce a high volume of air but at low pressure. Although rotary lobe blowers require minimal maintenance, they let some air escape. As such, this is not the most energy-efficient option, especially when compared to screw blowers. Since they were invented in the 1800s, rotary lobe blower technology hasn't changed too much. The main advancements have been focused on noise reduction.
Rotary Screw Blowers: The rotary screw blower combines male and female rotors that rotate and decrease the available volume between them. This causes the air to compress. At the start of the compression cycle, the inlet air fills the flute space and becomes trapped. The air is then continually compressed as the male and female rotors rotate with each revolution until the air pushes through the discharged outlet. Compared with traditional lobe blowers, the internal compression of rotary screw blowers reduces energy consumption by 30 percent. By eliminating pulses caused by lobe technology, screw blower noise levels are typically three-to-five times quieter than conventional tri-lobe blowers.
Centrifugal Blowers: When an air stream passes through this blower’s rotating impellers, the speed and volume increase. Centrifugal blowers actually change the airflow’s direction. The air or gas enters the fan wheel, turns 90 degrees, and accelerates before exiting the blower.
Multistage Centrifugal Blower: Used for creating pressure, circulating air, and creating suction, this blower can handle high pressure and high flow rates. It is ideal for creating high pressure from small volumes of air. As such, the devices are well suited for all operations where a variable flow at constant pressure is a requirement. Performance characteristics of these blowers generate a variable flow and power at a constant speed. To generate more flow, the impeller diameters need to be increased; more impellers are required to create more pressure.
What Industries & Applications Are Blowers Used In؟
Food and Beverage: includes meat processing, poultry, dairy product manufacturing.
Wastewater Treatment: the wastewater is introduced to millions of bacteria in the aeration tank. The bacteria feed on the organic waste and break down the wastewater into harmless byproducts of carbon dioxide, nitrogen and water. Because the bacteria need oxygen to survive, large quantities of compressed air are blown into the aeration tanks to speed up the activated sludge process.
Pneumatic Conveying: used to move any dry bulk material, including powders, granular forms, chips and pellets
Mining: provides ventilation into coal mines; removes methane gas from underground coal mine basins in a process called methane gas extraction
Cement Manufacturing: blowers aerate the air cement silos, ensure that the raw material remains in motion, cool the mixture after leaving the kiln, and feeds oxygen to the fire