Scroll compressors are used in air conditioning and refrigeration systems to compress refrigerant gas for cooling. They consist of two spiral sections, one stationary and one that orbits in a circle, creating a compression effect. They have few moving parts and are durable, accepting liquid without damage. They can be mounted upright or on their side, resulting in less vibration and noise.
A scroll compressor is used in air conditioning and refrigeration systems to compress refrigerant gas for cooling. A slide system design has been around since the early 20th century, but precision machining techniques didn’t support commercial development until the 1920s. A snail consists of two spiral sections, one stationary and one that orbits in a circle, creating a compression effect necessary for refrigeration.
Refrigeration systems require a compressor to function properly, as the refrigerant gas must be compressed, then expanded to reduce the gas pressure. This pressure drop, combined with the transition of the refrigerant from liquid to vapor, lowers the temperature of the gas circulating within the metal coils and provides cooling. The low pressure gas then returns to the compressor and the cycle is repeated until the desired temperature is reached.
The scroll compressor design consists of two spiral or spiral parts, one welded into the compressor body and the other connected to an electric motor. When the motor starts, the moving snail makes an orbital motion, which could be described as the motion of a marble in a pan. The motion is circular, rather than a back and forth motion found in reciprocating compressors.
As the scroll orbits the stationary portion, pockets of refrigerant gas are trapped between the two portions of the scroll. The gas inlet of the scroll compressor is on the outside of the widest part of the scroll and the high pressure outlet is in the centre. The trapped gas moves around the coil, moving in a smaller and smaller area, which results in a higher pressure. When the gas reaches the center of the scroll unit, it is at the desired head pressure and exits the compressor.
A scroll compressor can be very durable, because there are few moving parts and the unit is not prone to some types of compressor damage. Reciprocating compressors that use pistons can be damaged if liquid refrigerant enters, because the liquid does not compress and can damage or even destroy a compressor. A scroll will accept liquid, because the movable sliding section is not locked against the stationary part and may move slightly if liquid enters it. The effect of liquid on a compressor is called “liquid knock” and a scroll compressor is a good choice if knocking is likely to occur.
Reciprocating compressors use pistons and cylinders, similar to an automobile engine, to compress the refrigerant gas. Pistons have rings that seal the cylinder walls and allow gas pressure to build. As the rings and cylinders wear, gas can bypass the pistons, resulting in compressor rundown and possible compressor failure. A scroll compressor is sealed by the two scroll elements sliding against each other and maintaining compression with less gas bypass. Compression efficiency can increase over time, as the sliding scroll polishes the compressor surfaces and improves sealing ability.
Most compressors need to be installed in a specific orientation, vertical for most reciprocating compressors or sideways for screw compressors. Since the late 20th century, manufacturers have had the choice of supplying scroll compressors which can be mounted upright or on their side, allowing for flexibility in the customer’s build. The orbital motion of the scrolls also results in less vibration, which can make them an advantage in applications where noise or vibration needs to be controlled.
Protect your devices with Threat Protection by NordVPN
