Dust collector

A filter apparatus comprising, in combination,

• a hopper,
• an exhaust chamber,
• a wall separating said hopper and said exhaust chamber, said wall including an opening,
• means for filtering contaminated air flowing through said opening from said hopper, said filtering means including a hollow filter assembly comprising filter medium and having upper and lower ends, said upper end of said filter assembly registering with said wall opening and said hopper being generally sealed from said exhaust chamber except through said wall opening and said filter medium of said filter assembly, and said filtering means further including an end plate generally parallel to said wall at said lower end of said filter assembly.
• means defining an inlet into said hopper for introducing contaminated air into said hopper so that said contaminated air is caused to flow to said exhaust chamber through said filter medium and airborne contaminants are accumulated on said filter medium,
• means for selectively directing reverse pulses of air into said wall opening from said exhaust chamber whereby said reverse air pulses enter said filter assembly and generate an increased air pressure in said filter assembly and airflow through said filter medium in the reverse of the direction of contaminated airflow to remove accumulated contaminants from said filter medium,
• and said air pulse direction means being spaced above said wall opening and constructed to accelerate the air emitted toward said wall opening such that said air pulses propagate toward said wall opening in a conse-shaped pattern with the base of the cone engaging said wall at said wall opening and surrounding said wall opening, such that said air pulses enter said wall opening at a speed of 150 to 250 feet per second, and such that said air pulses propagate downwardly into said filter assembly and impinge directly upon said end plate and do not impinge upon said filter medium.

A filter apparatus comprising, in combination,

• a hopper,
• an exhaust chamber,
• a wall separating said hopper and said exhaust chamber, said wall including an opening,
• means for filtering contaminated air flowing through said opening from said hopper, said filtering means including a hollow filter assembly comprising filter medium and having upper and lower ends, said upper end of said filter assembly registering with said wall opening and said hopper being generally sealed from said exhaust chamber except through said wall opening and said filter medium of said filter assembly, and said filtering means further including plate means generally parallel to said wall at said lower end of said filter assembly,
• means defining an inlet into said hopper for introducing contaminated air into said hopper so that said contaminated air is caused to flow to said exhaust chamber through said filter medium and airborne contaminants are accumulated on said filter medium,
• means for selectively directing reverse pulses of air into said wall opening from said exhaust chamber at a controlled rate of speed so that said reverse air pulses enter said filter assembly and generate an airflow through said filter medium in the reverse of the direction of contaminated airflow to remove accumulated contaminants from said filter medium,
• and said air pulse directing means being spaced above said wall opening and constructed to accelerate the air emitted toward said wall opening such that said air pulses propagate toward said wall opening in a cone-shaped pattern and so that, as a result of said speed being controlled, said air pulses enter said wall opening at preselected speed sufficient to cause said air pulses to propagate downwardly into said filter assembly without impinging on the inner walls thereof and said propagating air impinges directly upon said end plate after which said air proceeds to occupy said filter and produce the reversed airflow through said flow medium.