Natural gas is primarily compressed using two main types of compressors: reciprocating compressors and screw compressors.
Reciprocating Compressors
Reciprocating compressors utilize a piston within a cylinder to compress the gas. This is a positive displacement method. Here's a breakdown:
- Intake: Natural gas enters the compressor through an intake manifold and flows into the compression cylinder.
- Compression: A piston moves within the cylinder, reducing the volume and increasing the pressure of the gas. This is the core of the compression process.
- Discharge: Once the desired pressure is reached, the compressed gas is discharged from the cylinder at a higher pressure than it entered.
Reciprocating compressors are well-suited for applications requiring high pressure ratios and varying flow rates.
Screw Compressors
Screw compressors use rotating helical screws to compress the gas. As the screws turn, they trap pockets of gas and force them into a smaller volume, increasing the pressure.
- Rotor Engagement: Two intermeshing screws (rotors) rotate, drawing gas into the space between them.
- Volume Reduction: As the rotors continue to turn, the space between them decreases, compressing the trapped gas.
- Discharge: The compressed gas is then discharged through an outlet port.
Screw compressors are generally more reliable and require less maintenance than reciprocating compressors, particularly in applications with consistent flow rates. They are known for their smooth and continuous operation.
