Mechanical Behavior of Positive Displacement Compressor System

Compressors are supreme movers of air and gas and process industries. Like pumps, the compressors increase pressure on a fluid and can transport the fluid through a pipe.

FREMONT, CA: In a positive displacement compressor system, a specific volume of gas is confined in a given space and then compressed by reducing this limited volume of space. The gas is expelled into the vessel system or discharge piping at this elevated pressure in a positive displacement compressor system. Even though positive displacement compressors come in a wide range of geometries and configurations, the most important process machines are helical screw rotating machines and piston compressors. This is because positive displacement machines work on different fluid parts simultaneously. As a result, their operating speed and mechanical behavior differ greatly from dynamic devices. Reciprocating compressors, screw compressors, and scroll compressors are examples of this type of compressor.

1) Rotary Compressor System

The rotary screw compressor is a positive displacement machine with three distinct working phases: compression, suction, and discharge. Two counter-rotating helical screws are arranged in a compressor casing, with the discharge nozzles and gas inlet at opposite ends. Rotary screw compressors can also compress process gases. These compressor systems are further classified as lobe, screw, liquid ring, scroll, and vane.

Rotary Lobe Compressor System - Rotary lobe compressor systems provide air in pneumatic conveying lines for solids or powder.

Screw Compressor System - A portable or stationary screw compressor system typically used for continuous operation in industrial and commercial applications.

Liquid Ring Compressor System: A vacuum pump can also function as a gas compressor. An induction motor typically powers the liquid-ring pumps.

Scroll Compressor System: A scroll pump and scroll vacuum pump, the compressor system compresses or pumps fluids such as gases and liquids using two interleaved spiral-like vanes. One advantage is that they run more quietly, smoothly, and consistently than other types of compressors.

The device could be a vacuum pump or a compressor with appropriate port connections.

2) Reciprocating Compressor System

The reciprocating or piston compressor system moves gas from one pressure level to another higher pressure level by driving a piston within a cylinder with a crankshaft. They can be mobile or stationary, multi-staged or single-staged, and powered by internal combustion engines or electric motors. Small reciprocating compressors power automotive applications, while larger reciprocating compressors are still used in large industrial applications. The reciprocating compressor system, like the rotary, is divided into the diaphragm, double-acting and single-acting compressor systems.

Diaphragm Compressor System: This is an alternative to the traditional reciprocating compressor. It is also known as a membrane compressor. These are commonly used for compressed natural gas, hydrogen, and other applications.

Double Acting Compressor System - The double-acting cylinder designs have two compressions, discharge areas and suction.

Single-Acting Cylinder System: Single-acting cylinder designs have a single compression, discharge, and suction area.