The filter system for filtering particulate material from a generally unidirectional
fluid stream comprising a first filter removably positioned in the fluid stream
and a second filter removably positioned in the fluid stream downstream of the
first filter. The first filter comprises a pre-filter and includes a layer of fluid-permeable
material having a plurality of spaced-apart openings extending completely therethrough.
The method of utilizing the fluid filter system of this invention is also disclosed
and comprises the steps of: (1) removably positioning a first filter in the fluid
stream; and (2) removably positioning a fluid-permeable second filter in the fluid
stream downstream of the first filter. The first filter may be removed from the
fluid when it becomes restrictive to air flow. The system may be operated so that
the air may be passed through the second filter until the second filter becomes
clogged or restrictive to air flow. The filters may be positioned in an air discharge
passageway associated with a paint spray booth or may be positioned in an air intake
passageway extending into a heating system, a ventilating system or an air conditioning system.
