When a machine manufacturer was suddenly faced with an actuator height
restriction problem at one of its customers sites, it called upon its
supplier for a bit of lateral thinking
Solids processing equipment specialist, Aeromatic-Fielder was faced with
a bit of a challenge recently when it was called upon to simplify the
filter cleaning process for a pharmaceutical granulation unit in use at
one of its customer‘s sites. The filters, which prevent granules from
leaving the unit during drying, need to be cleaned for every new batch.
In the original system, a pneumatic cylinder was used to raise the
filters out of the process chamber and pass them by water jets, with
periodical complete removal for autoclaving. Hitherto, there was space
for this process but new constraints have restricted the available
lifting height to just 2,560mm. Given that the overall cylinder stroke
needed to raise the filters for water cleaning and lower them for removal
is 3,335mm, the problem becomes apparent.
At this point, Norgren was called in to help and the pneumatics
specialist decided that a telescopic design might provide the best
solution, and a novel telescopic cylinder was duly developed. The outer
cylinder strokes 1,135mm and operates during the water cleaning cycle.
The piston rod of the outer cylinder serves as the casing for the inner
cylinder, which has a stroke of 2,300mm and lowers the filter for
removal. Clean room conditions prohibit external air connections to the
front end of the cylinder for the inner cylinder return stroke, so all
pneumatic tubing and electrical cables are routed to the rear of the
assembly in a flexible cable train running between the inner and outer
cylinder barrels. These connections all terminate at one external point
for easy configuration.