Quincy Compressor QSI Series Instruction Manual

Also see for QSI 1000: Instruction manual Instruction manual

Contents

Quincy Compressor QSI Series Instruction Manual Manual pdf 13 page image

Section II - DescriptionQuincy Compressor-QSI® 7Air FlowWith the compressor operating, a partial vacuum isproduced at the compressor inlet. Air entering via thecompressor air filter flows through the air inlet valve intothe rotor housing where it is compressed, then dischargedinto the air/fluid reservoir. Compressed air passesthrough the complete system then through a minimumpressure check valve to the service connection.Cooling SystemFluid CoolersFluid coolers may use either air or water as a coolingmedium. The following descriptions point out the majordifferences between the two types of coolers.Air-cooled Fluid CoolersThe air-cooled fluid cooler and aftercooler are of thefinned aluminum tube, one piece design. Ambient air isforced through the fins by a motor driven fan, cooling thefluid and air in the tubes. To maintain proper compressoroperation, the ambient air temperature should not exceedthe temperatures listed in Appendix B - Technical Data.The cooler fins must be kept clean at all times. Fluidleaving the receiver passes through a thermal mixingvalve before traveling on to the cooler. The purpose ofthe thermal valve is to maintain a minimum fluiddischarge temperature at the compressor ofapproximately 180°F.Water-cooled Fluid CoolersWater-cooled fluid coolers are of the shell and tubedesign. Fluid passes through the shell transferring itsheat to the water flowing through the tubes. Fluidleaving the cooler does not pass through a thermalmixing valve as in an air-cooled unit, but goes directly tothe fluid filter and the compressor. Fluid dischargetemperature at the compressor is maintained by a watertemperature regulating valve located in the dischargewater line. The water temperature regulating valve uses aprobe to sense fluid temperature and opens and closes,governing water flow through the cooler.AftercoolersAftercoolers reduce the amount of water in the dischargeair. They are used to lower the temperature of thedischarge air thereby condensing water vapor from thecompressed air. This allows most of the contained waterto be trapped and expelled from the unit, reducing waterrelated problems downstream.Air-cooled aftercoolers are part of the air-cooled fluidcooler. Cooling air from the fan is blown through theaftercooler and the fluid cooler.Water-cooled aftercoolers are placed in series with thefluid cooler. Incoming water is first directed through theaftercooler and then on to the fluid cooler.A combination moisture separator and water trap isprovided for collecting and expelling water to thecustomer’s drain.