Pneumatic conveyor blowers operate continuously

The Shark range of dry-running, rotary lobe blowers from Rietschle (UK), is now an extended family. Thirteen models are available in both pressure and vacuum versions, with capacities ranging from 15m3/h to 8300m3/h. Suitable for pressure duties up to 1bar or vacuum to 0.5bar (abs), they deliver nearly constant, oil-free air or vacuum, at varying pressures.

The gearboxes of these large volume blowers are robustly constructed for continuous operation (up to 60,000 h, maintenance-free), in pneumatic conveying and in process applications ranging from aeration to gas stirring.

The triple lobe design hugely reduces flow and pressure pulsations: to the extent that resonance silencers are not required on the discharge side, even when several blowers are connected in parallel.

They are available either as bare shaft units, or as compact, skid-mounted assemblies complete with drive motor, non-return and safety valves, connecting compensator and silencers.

For indoor and external operation, the compact assembly can be enclosed in an acoustic box to reduce the operating noise level by a further 20 dB(A).

Dynamically balanced prior to assembly, the contra-rotating rotors are driven by helical toothed drive gears, for silent running and high load-carrying capacity.

The hardened gear teeth are ground and polished to minimise geometric errors, and to maintain fine operating tolerances between the lobes.

The rotor housing is free of any sealing or lubricating materials, and isolated from the oil-lubricated drive gears.

Thanks to the compact nature of the design, only limited foundations are needed, which reduces installation costs.

Servicing is minimal, and frequency control is available as an optional extra, both of which make for economies in operation: a relevant factor given the longevity of these units.