While selecting scroll compressors we generally consider two main factors, they are: Selection Criterion of Scroll Compressors Scroll compressor mainly used in HVAC services and refrigeration are in vertical in orientation in which the scroll sets are at the upper part of motor shaft. The structure f the scroll compressor are completely hermetic which means it is enclosed in the shell of the compressor and the shell of the compressor are cylindrical welded steel shell. These compressors are also used for simplifying the design of piping because they do not need external connection for the purpose of primary coolant. Quite operation and small size of the scroll compressor enable the unit for building in high power density computers. This also results in small free volume but it reduces its liquid handling efficiency. This results into small shell enclosures and reduced cost. Therefore they do not need spring suspension. Scroll compressor run smoothly and they have an added advantage of compact size. Thus they were successful in obtaining a result in which they discovered that the design in which scroll compressors were involved achieved higher energy efficiency in operation and also had better reliability. In 2006 Stoelting, manufacturers of equipment’s used in food services changed their design of a machine of soft serve ice cream from reciprocating compressor to scroll compressor. The manufacturers of Copeland scroll compressors, Emerson climate technologies stated that scroll compressors have 70 percent less moving parts as compared to various reciprocating compressors. This eventually results in increasing the reliability of a scroll compressor. In any scroll compressor there are very less moving parts as compared to reciprocating type compressors. Therefore desired discharge pressure is obtained with the motion of scrolls of the compressors. When the gas moves in small internal pockets continuously then both its pressure and temperature starts to rise. At that place compressed gas is discharged. In outer part of scroll, the gas is sucked by the pocket and after that it is moved to the Centre of scroll. When the scroll rotates, the gas pockets are generated in between two scrolls. The rotating scroll is connected with the crankshaft of the compressor. The first spiral rotates in a well defined path by the mating attached scroll. The scroll compressor has two spirals or scrolls in which one of them is moving while the other is attached or fixed with the body of the compressor. Scroll compressors are generally more efficient as compared to other compressors. When a scroll compressor is operated in reverse then it is known as a scroll expander and it has the ability to produce mechanical work. Huge air conditioning systems, residential central heat pumps and some automotive air conditioning use scroll compressor in place of other reciprocating, rotary and wobble plate compressors. This type of compressors are known as wear in at the place of wear out but the other parts like Oldham ring of the scroll compressor can wear out. In some scroll compressors, pressurised discharge gases are used for pushing both the scrolls together which completely reduce the requirement of tip seals and also enhance the sealing with use. Once they are worn out, they are replaced with new ones. These spiral – shaped seals can also help in lowering down friction. Leaks in the axial gaps can be prevented with the help of tip seals of spiral – shaped which is placed in the groove made on the tips in both spirals. The relative motion should be same as in case when one is orbiting. Another method used for the generation of compression motion is co – rotation of the scrolls in a motion which is synchronous with offset Centre of rotation. Orbital motion can be provided by an eccentric shaft but the scroll should not be rotated. Generally, one scroll of the scroll compressor is fixed and the other scroll orbits eccentrically having no rotation, leading to trapping and compressing or pumping the fluids in between scrolls. In a scroll compressors there are two inter-leaving scrolls which are used for pumping, compressing or pressurising the fluids like gases and liquid. Scroll compressors are used as automobile supercharger in which it is called as scroll type supercharger, in air conditioning and as vacuum pump. Scroll compressor is defined as a device which is used for compressing the refrigerant or air. Scroll Compressor: Definition, Working, Applications, Advantages, Disadvantages, Selection Criteria & Reliability :- Scroll compressors are also known as scroll pump, spiral compressor and scroll vacuum pump. Scroll Compressor What is a Scroll Compressor?
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