Powerex manufactures two different scroll compressor systems: an open oilless scroll compressor and an enclosed oilless scroll compressor. Powerex was the first company to package NFPA 99 compliant scroll compressor systems. Today, Powerex designs and manufactures a complete line of NFPA 99 compliant scroll compressor systems. Along with manufacturing air compressors, they build many of the major components, such as UL control panels, desiccant dryers, dew point monitors and internally lined air receivers in-house.
Powerex's innovative Open Scroll Technology is completely oilless, extremely quiet, energy efficient and requires little maintenance. Mounting the open scroll compressor on the tank itself maximizes available floor space and allows for easy access to the compressors for maintenance. Poweres offers several models of their STS Simplex and STD Duplex line of open oilless scroll compressors.
Click Here to see the complete line of Powerex Open Oilless Scroll Compressors.
The sound enclosure cabinets of Powerex’s Enclosed Scroll Compressor Systems decrease noise levels even further, allowing the compressor system to be installed right at the point of use. The small footprint also helps maximize available floor space. The rotary design has few moving parts making it reliable and easier to maintain. The self-lubricating tip seals, and absence of a gearbox means the pump is truly 100% oil free. Powerex offers several models of their SES Simplex and SED-SEO Multiplex line of enclosed oilless scroll compressors.
Click Here to see the complete line of Powerex Enclosed Oilless Scroll Compressors.
In addition to offering complete oilless scroll compressor systems, Powerex scroll compressor bare pumps are available in a range of horsepowers.
Click Here to see the Powerex Scroll Compressor Bare Pumps available through mdi.
Benefits of a Powerex Scroll Compressor:
A scroll compressor, also known as a spiral compressor, is a device for compressing air or refrigerant. It consists of a very simple design since it only has 1 moving part. The compressor is made of of two spiral shaped elements. One is stationary and the other moves in eccentric circles. This causes the air or gas to be trapped between the two spiral elements at the suction side and then transported to the center of the spiral, compressing the air or gas. Since there are so little moving part and there is no oil and the compressed air it produces is oil-free. Scroll compressor systems are used for multiple industrial manufacturing processes. A scroll compressor operating in reverse is known as a scroll expander, and can be used to generate mechanical work from the expansion of a fluid, compressed air or gas. The compression process occurs over approximately 2 to 2½ rotations of the crankshaft, in comparison to one rotation for rotary compressors, and one-half rotation for reciprocating air compressors. The scroll pump discharge and suction processes occur for a full rotation, compared to less than a half-rotation for the reciprocating suction process, and less than a quarter-rotation for the reciprocating discharge process.
Reciprocating compressor have multiple cylinders (usually anywhere from two to six), while scroll compressors only have one compression element. The presence of multiple cylinders in reciprocating compressors reduces suction and discharge pulsations. The more steady flow yields lower gas pulsations, lower sound and lower vibration of attached piping, while having no influence on the compressor operating efficiency.
Scroll compressors are known for operating more smoothly, quietly, and reliably than conventional compressors in some applications. Unlike piston compressors, the orbiting scroll’s mass can be perfectly counterbalanced, with simple masses, to minimize vibration. The scroll’s gas processes are more continuous. Additionally, a lack of dead space in the scroll compression process gives an increased volumetric efficiency. Since there are only a few moving parts there is no need for oil, and maintenance is very simple.
Scroll compressors never have a suction valve, but depending on the application it may or may not have a discharge valve. The use of a dynamic discharge valve is more widely used in high pressure ratio applications, typical of refrigeration. Normally, an air-conditioning scroll does not incorporate a dynamic discharge valve. The use of a dynamic discharge valve increases scroll compressor efficiency over a wide range of operating conditions, especially when the operating pressure ratio is well above the built-in pressure ratio of the compressors. If the compressor is designed to operate near a single operating point, then the scroll compressor can actually increase efficiency around this point if there is no dynamic discharge valve incorporated.
The equal entropy efficiency of scroll compressors is slightly higher than that of a typical reciprocating compressor when the compressor is designed to operate near one selected rating point. Scroll compressors are more efficient in this case because they do not incorporate a dynamic discharge valve that introduces added throttling losses. In comparison to the reciprocating compressor at higher pressure ratio operation the efficiency of a scroll compressor that does not have a discharge valve begins to decrease. This is because of under-compression losses that occur at high pressure ratio operation of the positive displacement compressors that do not incorporate a dynamic discharge valve. The scroll compression process is almost 100% volumetrically productive in pumping the trapped air. The suction process creates its own volume, independent from the compression and discharge processes further inside. Because it is not practical for the piston to touch the head or valve plate, reciprocating compressors by comparison leave a small amount of compressed gas in the cylinder. That remaining gas from the last compression cycle then occupies space intended for suction air. The reduced quantity (i.e. volumetric efficiency) depends on the suction and discharge pressures with greater reductions occurring at higher ratios of discharge to suction pressures.
Scroll compressors have fewer moving parts than reciprocating compressors which improve reliability. Scroll compressors have 70 percent fewer moving parts than conventional reciprocating compressors.
Since scroll compressors are very compact and smooth running, they do not require spring suspension.
Powerex Scroll Compressor Systems are available in the following HP:
Léon Creux designed the first scroll compressor and patented the design in 1905 in France and the U.S. He invented the compressor as a rotary steam engine concept, but a working prototype was never constructed due to the fact that the metal casting technology of the period was not sufficiently advanced enough since a scroll compressor demands very tight tolerances to function effectively. The first feasible scroll compressors appeared on the market after World War II, when higher-precision machine tools enabled their construction.