Grizzly G9958 - Manual (Page 15)

G9958 4 H.P. Dust Collector -13-
Material Selection
General
You have many choices regarding main line and
branch line duct material. In most commercial
workshops, the main line and branch lines are
usually metal duct. Flexible hose is then used to
connect each machine to the branch lines. In the
case of small home shops, flexible hose may be
used for both main line and branch line ducts.
Plastic duct is also a popular material for home
shops. Please be aware that there is a fire or
explosion hazard if plastic duct material is used
for dust collection without being grounded against
static electrical charge build-up. This topic will be
discussed later in the manual.
The Model G9958 can be operated as either a
stationary or a mobile unit. There are advantages
and disadvantages to both set-ups. The advan-
tage of the mobile system is eliminating the cost
of many ducts and fittings. On the other hand, the
stationary system is more versatile and conve-
nient.
The Model G9958 is designed to be a central dust
collector system. Locate the dust collector in an
out of the way location such as a corner or sepa-
rate room. The dust collector is capable of col-
lecting dust from up to four machines running
simultaneously. Because of the large suction
capacity of the Model G9958, great flexibility is
possible in the planning and designing of your
dust collection duct layout. Grizzly offers a com-
plete line of dust collection accessories for setting
up a stationary system. Additionally, Grizzly offers
a complete guide book entitled
Dust Collection
Basics.
Whatever system you choose, always make sure
there are no open flames or pilot lights in the
same room as the dust collector. There is a risk of
explosion if dust is dispursed into the air.
METAL DUCT
Metal duct comes in many varieties. Stove pipe,
heating/ventilation duct and duct made especially
for dust collection are all options. Advantages of
metal duct is its conductivity and that it does not
contribute to static electrical charge build-up.
However, static charges are still produced when
dust particles strike other dust particles as they
move through the duct. Since metal duct is a con-
ductor, it can be grounded quite easily to dissipate
any static electrical charges. However, metal duct
is generally more expensive than plastic duct and
it is not usually airtight unless specifically manu-
factured for dust collection. Specially manufac-
tured metal duct, on the other hand, is quite
expensive. Metal duct is also generally more diffi-
cult to cut and assemble.
FLEXIBLE HOSE
Flexible rubber hose, polyethylene, plastic flex-
hose and other flexible ribbed hose is generally
used for short runs, small shops and at rigid duct-
to-tool connections. There are many different
types of flex hose on the market today. These are
manufactured from materials such as polyethyl-
ene, PVC, cloth hose dipped in rubber and even
metal, including steel and aluminum.
There are also many kinds of pure plastic flexible
hose, such as non-perforated drainage type hose
and dryer vent hose. Drainage type hose, while
being economical, does not quite have the flexi-
bility required for dust collection. The inside of the
duct is also deeply corrugated and can increase
the static pressure loss by as much as 50% over
smooth wall duct. Dryer vent hose, while being
completely flexible, is non-resistant to abrasion
and has a tendency to collapse in a negative
pressure system.
If using flex-hose, you should choose one of the
many types that are designed specifically for the
movement of solid particles, i.e. dust, grains and
plastics. However, the cost of specifically
designed flexible duct can vary greatly. Grizzly
offers polyethylene hose which is well suited for
SECTION 5: DESIGNING THE SYSTEM