MAXIMA Twin Lobe Roots BlowersÂ positive displacement compressors come in two models twin lobe. They are engineered and manufactured by capable and experienced personnel in a modern plant with the latest machines and also with the latest tooling. Production is controlled by close inspection, tests, and attention to the smallest detail. Reliable field service is maintained by factory trained personnel twin lobe compressors to range in capacity up to 50, 000 m3hr. The rotary positive displacement compressor twin lobe model has two figures eight impellers rotating in opposite directions and twine lobe model has three impellers in each shaft rotating in opposite direction. As each lobe of an impeller passes the compressor inlet, it traps a quantity of air equal to exactly one-fourth the displacement of the compressor. This entrapment occurs four times per revolution, moving the entrained air around the case to the compressor outlet. Ground helical timing gears accurately position the impellers in relation to each other, maintaining the minute clearances so vital to the high volumetric efficiency of the rotary positive compressor. Because the compressor operates with very close internal tolerances, a slight amount of air escapes past the operating clearances back to the suction side of the compressor. This leakage, defined as 'slip' is a predictable constant volume for any given compressor at any given pressure. For ease of calculation, this leakage is expressed in compressor rpm. A standard slip, based on handling air at the standard condition, has been established for each compressor size. For gases having a specific gravity other than 1.0, the slip will vary and this must be taken into consideration when calculating the total operating speed of the unit. The twin lobe compressor is built with the closest possible tolerances to give highest volumetric efficiency. Every twin lobe compressor is tested before shipment.