Axial flow compressor

An axial flow compressor is a type of compressor that operates on the principle of rotating blades to compress the fluid. It is commonly used in gas turbine engines to compress air before it enters the combustion chamber.

Roots blower

A Roots blower, also known as a positive displacement blower, is a type of compressor that operates by trapping air between two meshing lobes and then pushing it towards the outlet. It is commonly used for applications that require high flow rates at low pressure differentials.

Vane blower

A vane blower, also known as a rotary vane compressor, is a type of positive displacement compressor that uses rotating vanes inside a cylindrical chamber to compress the air. It is commonly used for applications that require moderate flow rates and pressures.

Reciprocating compressor

A reciprocating compressor is a type of positive displacement compressor that uses a piston and cylinder arrangement to compress the air. It operates by drawing air into the cylinder, compressing it, and then discharging it. Reciprocating compressors are commonly used in applications that require high pressures.

Non-positive displacement compressor

A non-positive displacement compressor is a type of compressor that does not trap and compress a specific volume of air. Instead, it operates by continuously forcing air through the compressor at a high velocity. The pressure increase in a non-positive displacement compressor is achieved through the conversion of kinetic energy into pressure energy.

Explanation

Among the given options, the axial flow compressor is the only non-positive displacement compressor. Axial flow compressors operate by continuously forcing air through a series of rotating blades at a high velocity. The blades accelerate the air, increasing its kinetic energy, and then convert it into pressure energy as it passes through the compressor stages. This type of compressor is commonly used in gas turbine engines due to its ability to handle large volumes of air at high speeds.

The other options, such as the Roots blower, vane blower, and reciprocating compressor, are all positive displacement compressors. They operate by trapping and compressing a specific volume of air before discharging it. Positive displacement compressors are generally used in applications that require a higher degree of compression and pressure control.