Compressor

Application Overview

     A compressor is a mechanical device that takes in a medium and compresses it to a smaller volume. Compressors can either increase or decrease a given mass to a lower or higher pressure. A mechanical or electrical drive is typically connected to a pump that is used to compress the medium.

Compressors have many everyday uses, such as:

• Air conditioners, (car, home)
• Air pumps
• Home and industrial refrigeration
• High pressure car washes
• Hydraulic compressors for industrial machines
• Air compressors for industrial manufacturing

     Compressors are used by many industries that depend on the power of compressed gas or fluid to power manufacturing processes of all kinds.

There are several different compressor types:

• Rotary screw compressor
  Two helical rotors force gas into a chamber that decreases in size, thereby increasing the pressure of the gas. The screws in the rotary screw compressor can be lubricated with oil or non-lubricated. Oil-free compressors are used for gas that must remain clean and uncontaminated. Rotary screw compressors are typically sized from 30-200 horsepower.

• Reciprocating compressor
  One or more pistons are moved inside a cylinder to increase the gas pressure. This is similar to a combustion engine without the ignition of fuel. Just like a car, the pistons generate much heat so the reciprocating compressor is typically cooled by air or water. Multi-stage reciprocating compressors pass the compressed gas from one cylinder to another, increasing the pressure in each stage. Most industrial compressors are multi-stage, ranging from one to 500 or more horsepower.

• Centrifugal compressor
  Centrifugal compressors speed up and compress gas via a rotor with blades. Centrifugal force is used to force the air or gas to an outer chamber under higher pressure. Centrifugal compressors are designed to operate above 75-80% speed. Surging can occur below these speeds. This makes the centrifugal compressor ideal for continuous high duty operation.

Application Challenges

• Varied compressor I/O that must interface with the AC drive to control compressor functions.
• Reduce energy consumption
• Constant pressure regulation
• Constant torque load requirement
• Starting torque