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PAPST's New High Pressure Blower Assembly

Papst's new high pressure air blower assembly is suitable for use by OEM's for applications such as smoke detection and air sampling systems as well as small bore cooling systems.

Originally developed for use in demanding medical environments such as the treatment of obstructive sleep apnea requiring air at a pressure of about 20 cm H2O, the blower's unique combination of high pressure, controllability and long life make it ideal for many other applications where air has to be forced at controlled pressure through restricted apertures as in smoke or air samplers, ducting etc. The complete assembly comprises a variation of the Papst 933 2711 100 brushless DC motor fitted with a specially designed backward curved impeller measuring 147mm across x 9mm deep. The aluminium impeller weighs only 140 grams and is fitted to the rotor of the motor with three locked screws; the whole assembly being balanced at the factory to within 3µm in each plane. The motor itself measures only 30.2mm x 38.5mm diameter. EMA can provide a complete application package using a Papst open or closed loop VARIOTRONIC drive card plus blower and the company is able to work with OEMs to develop customised solutions for individual applications. Performance in terms of air-flow and pressure is a function of the impeller and the particular application. Without a housing, the assembly runs from an open loop drive card connected to a 14.5 volt supply, with a speed of 5000 rpm and current of 1.55Amps. With the assembly mounted into a customer's blower housing, a current of 0.9A resulted in a speed of 7700 rpm using a 22.5 volt supply. The motor uses three-phase brushless (Hall effect commutation) technology and its external rotor design contributes to overall efficiency and speed stability. Brushless motors offer many advantages over other permanent magnet motors. With no carbon brushes, they provide a very long 20,000 hours guaranteed lifetime limited only by the Sintec® bearings (much longer lifetimes are commonly achieved) and electronic commutation resulting in lower noise, no contamination and wide speed range (typically 300 rpm to 7,700 rpm).