Screw Compressors and Industrial Ammonia Refrigeration

If you are thinking about replacing or upgrading your current industrial ammonia refrigeration equipment, you have several important choices to make. For example, what size and type of compressors should you go with? Most businesses use either screw or reciprocating compressors and here is information to help you make an informed decision.

Reciprocating Compressors

A reciprocating compressor is similar to an internal combustion engine. A piston (with a seal attached) moves up and down inside a cylinder. The piston rod connects to a crankshaft (driven by a motor) which allows the up and down motion. As the piston comes down, it sucks refrigerant into the cylinder through an intake port. When the piston rises, it compresses the refrigerant and forces it out of the exhaust port.

Screw Compressors

A screw compressor works on the principle of a positive displacement machine. Two spiral rotors (resembling screw threads) turn side by side. As the rotors turn the spiral teeth mesh. This forms chambers inside the rotors which trap gas or liquid, compress it, and move it along like a screw conveyor. The compressor pulls refrigerant in through an intake opening and pushes it out of an outtake opening. Both reciprocating and screw compressors work well in industrial ammonia refrigeration systems. However, screw compressors offer several benefits.

Energy Savings

Screw compressors offer greater efficiency for large refrigeration systems. However, they are not as efficient as reciprocating compressors in smaller applications. Screw compressors are most efficient when running at full load. If your system requires compressors running at partial load, reciprocating compressors are the cost-effective option.

Wear and Tear

Screw compressors in large industrial ammonia refrigeration systems have fewer moving parts than reciprocating compressors. There are fewer parts to wear out, so you’ll get longer service with fewer maintenance concerns. This can save a lot of money over the years.