Brian Gaff (Sofa) explained :
I do remember we had a clean air room at one place I worked and most of the
dust was removed by a surface at high voltage which was continuously swept
into some kind of receptacle, and the filters seemed to last a long time, but
then this was a very large room and we are talking three industrial sized
units here.

Leeds University had a high voltage / plenum system for their
refectory, back in the 1960's.