On Wed, 29 Mar 2006 00:03:52 -0600, () wrote:

Can you support that statement?

Any standard industrial handbook of safety electrostatics. I'd suggest
Luttgens & Wilson's "Electrostatic Hazards" for readability, although
it's expensive and light on some tables of hard figures that you need to
do real work.

At any rate, in an industrial
setting the greater volume of air and dust being moved would have
the potential to create a more powerful static discharge.

"Discharges" are categorised into different causes, of which "sparks"
are only one.

The non-spark discharges occur around insulators and it's a relatively
easy matter to calculate their maximum energy. Put simply, the fact that
it's an insulator allows charge to build up, but it also limits the area
that can contribute to the discharge when it happens. Maximum energy is
a function of the materials, not the dust flow.

Sparks are discharges between conductors. These are rarer, as only an
insulated conductor builds up charge. However the whole conductor can
contribute, so there's no intrinsic limit on the discharge energy.
However we just don't build dust collectors this way.