Compressors and blowers are machines used to transport gasses, and change their fluid properties, especially the properties related to pressure. In many industrial applications, these devices can be found because air or some other gas is used as the working fluid, and it needs to be transported from one component to another and may need an increment in the pressure too.
Any HVAC system, turbine engine, or a system operating on a cycle using a gas as the working fluid uses compressors, such as turbine engines.
More about Compressor
Compressor is a device which increases the pressure of the air or other gas to a significantly higher level and transports it to another point by means of closed pipeline.
Depending on the movement of the fluid through the device the compressors are categorized into two classes as Positive displacement compressors and dynamic compressors. Positive displacement compressors have a mechanism to stop the fluid flowing back from the inlet while the pressurization and the fluid intake are intermittent. The dynamic compressors increase the pressure in successive stages of compression and the fluid flow remains continuous throughout the machine. Based on the direction of the flow, dynamic compressors are further divided into two classes as axial compressors and centrifugal compressors.
The mechanisms used to compress the gasses vary, but the general properties changed during the compression remain similar. The pressure of the gas increases and the temperature of the gas also increase along with the enthalpy. Gas compressors have a very high pressure ratio but deliver a relatively small volume of gas.
Compressors have numerous applications because, in systems, whenever a gas needed to be transported with high pressure, compressors are employed. In refrigeration and air-conditioning, in gas turbine engines, submarines, and in aircrafts compressors are used.
More about Blower
A fan is another mechanism to transport gases, but with relatively lower pressure to volume ratio; i.e. a fan delivers a large volume of gas with lesser increases in pressure.
A centrifugal fan with a higher pressure ratio than an average fan (output pressure / input pressure) is known as a blower. Blowers deliver a high volume transfer rate with a relatively greater pressure ratio to the ordinary fans but much less than the compressors. The pressure ratio of a fan is below 1.1 while blowers have a pressure ration of 1.1 to 1.2.
Centrifugal fans are used whenever the high volume needs to be transported with slight increment in pressure than a fan supplies. Automobile ventilation systems use a blower to draw large volumes of air to the air-conditioning system.
What is the difference between Compressor and Blower?
• Compressors deliver gas with a high pressure to volume ratio.
• Blowers deliver a larger volume of gas with lower pressure.