Ed,  suction can indeed be created by flow across an orifice.  It is
called the venturi effect and was used to measure air speed of old time
aircraft.

In industry, a common appliance was a compressed air line fitted with
a venturi and suction pipe which acted as a vacuum cleaner.  It could
also be used to suck powder or granules from a bin up the suction pipe
and into a machine.

However, it was very wasteful of compressed air and in these days of
environmental and economic responsibility, the compressed air venturi
has been pretty much replaced by an electric industrial vacuum cleaner
and other material feed conveyors.

Colin MacKinnon