HOW SCROLL COMPRESSOR WORKS

The scroll is a simple compression concept first patented in 1905. A scroll is an involute spiral which, when matched with a mating spiral scroll form as shown above, generates a series of crescent-shaped gas pockets between the two members. Scroll compressors work by moving one spiral element inside another stationary spiral to create a series of gas pockets that become smaller and increase the pressure of the gas. The largest openings are at the outside of the scroll where the gas enters on the suction side. As these gas pockets are closed off by the moving spiral they move towards the center of the spirals and become smaller and smaller. This increases the pressure on the gas until it reaches the center of the spiral and is discharged through a port near the center of the scroll. Both the suction process (outer portion of the scroll members) and the discharge process (inner portion) are continuous.

The moving scroll moves in an orbiting path within the stationary (fixed) scroll as it creates the series of gas pockets. During compression, several pockets are being compressed simultaneously, resulting in a very smooth process. By maintaining an even number (6 in a Copeland Scroll compressor) of balanced gas pockets on opposite sides, the compression forces inside the scroll work to balance each other and reduce vibration inside the compressor.

The scroll compressor design also provides more advantages vs. other compression technologies. By eliminating the use of a fixed cylinder and a piston or single sided compression mechanism, the compressor can use the scrolls to eliminate wasted space in the compression chamber and avoid recompression that you see in standard reciprocating compressors. This reduces energy wasted on compressing gas again and again during operation. The scroll compressor design also eliminates the need for suction and discharge reeds needed to control gas flow in single-sided compression processes like reciprocating and rotary compressors. These components are sensitive to problems in the refrigeration process like liquid and debris damage.

Copeland Scroll compressors are unlike other scroll compressors that use sealing devices and sensitive manufacturing processes to maintain the compression pockets. The scroll elements in a Copeland Scroll compressor are in contact only with each other and are designed to wear in to each other to eliminate imperfections that might cause leaks in other compressor designs. This allows Copeland scroll compressors to maintain their high levels of performance throughout their life.

In addition to this wear in process Copeland Scroll compressors also have design features to handle bigger problems inside the system. The scrolls are designed to separate temporarily if they encounter liquid or debris and pump the material out of the discharge before they come back into contact and resume compressing gas. This small amount of movement is designed in to allow the compressor to pass the material out of the gas pocket without damaging any of the surfaces and creating leaks or failures.