Electrostatic dust filter

Claim 2

AN ELECTROSTATIC FILTER FOR COLLECTING ELCGRICALLY CHARGED PARTICLES IN A POROUS LAYER, SAID FILTER COMPRISING A POROUS FILT MEMBER HAVING A SURFACE EXTENDING ACROSS THE PATH OF MOVEMENT OF SAID PARTICLES, SAID FILTER MEMBER INCLUDING A GROUNDED METAL SUPPORT AND A FIBRIC FILTERING ELEMENT DISPOSED DIRECTLY ON SAID SUPPORT, MEANS FOR MAINTAINING A SUBSTANTIALLY CONSTANT, UNDIRECTIONAL ELECTRIC FIELD AT SAID SURFACE IN A DIRECT GENERALLY PERPENDICULAR TO THE SURFACE AND OF POLARITY TO DRIVE SAID PARTICLES TOWARD THE SURFACE, AND MEANS FOR MAINTAINING THE STRENGTH OF THE ELECTRIC FIELD SUCH THAT NO CORONA CAN OCCUR.

Claim 3

An electrostatic filter as defined in claim 1 and including a grounded metal support for said filter member, said means for maintaining an electric field comprising at least one metal plate extending substantially parallel to the surface of the filter member, and means for applying a high voltage to said plate.

Claim 4

An electrostatic filter for collecting electrically charged particles in a porous layer, said filter including at least one filtering means, said filtering means having a grounded electrically conducting support means and a filter element disposed on said support means, said filter element comprising a fabric capable of filtering and collecting said particles, duct means for directing a stream of gas carrying electrically charged particles to flow through said filtering means, means for maintaining a substantially constant, unidirectional electric field adjacent the surface of said filter element in a direction to drive said particles toward the filter element and means for maintaining the electric field of a strength such that no corona can occur.

Claim 5

An electrostatic filter for collecting electrically charged particles in a porous layer, said filter including at least one filtering means, said filtering means having a grounded electrically conducting support means and a filter element disposed on said support means, said filter element comprising a fabric capable of filtering and collecting said particles, duct means for directing a stream of gas carrying electrically charged particles to flow through said filtering means, means for maintaining a substantially constant, unidirectional electric field adjacent the surface of said filter element in a direction to drive said particles toward the filter element and means for maintaining the electric field of a strength such that no corona can occur.

Claim 6

An electrostatic filter as defined in claim 3 having means below said filtering means for receiving particles removed from the gas, and means separated from said particlereceiving means for discharging clean gas after passage through the filtering means.

Claim 7

An electrostatic filter as defined in claim 3 in which said stream of particle-carrying gas is directed upwardly through said filtering means, and means above the filtering means for discharging clean gas after passage through the filtering means.

Claim 8

An electrostatic filter as defined in claim 3 in which said filtering means includes a grounded metal support for said filter element, a metal plate extending substantially parallel to the surface of the filter element, and means for applying a high voltage to said plate.

Claim 9

An electrostatic filter as defined in claim 3 which includes a plurality of filtering means, each of the filtering means comprising a grounded metal support and a fabric filter element disposed to form the walls of a passageway, means for directing said gas to flow through said walls and passageways, metal plate means disposed substantially parallel to the surfaces of the filter elements, and means for applying a high voltage to each of said plate members.

Claim 10

An electrostatic filter as defined in claim 7 in which said passageways are generally rectangular in cross section, and said plate members are flat plates extending substantially parallel to the sides of the rectangles.

Claim 11

An electrostatic filter as defined in claim 7 in which said passageways are circular in cross section, and each of said plates is of tubular configuration disposed coaxially with one of the passageways.

Claim 12

An electrostatic filter as defined in claim 3 in which said duct means for directing gas includes means for electrically charging particles carried by the gas.

Claim 13

An electrostatic filter as defined in claim 10 in which said charging means includes a plurality of grounded plates extending in the direction of movement of said gas stream, a plurality of wires disposed between said plates and parallel thereto, and means for applying a high voltage to said wires to electrically charge the particles passing through the charging means.

Claim 14

An electrostatic filter as defined in claim 11 in which said duct means for directing gas from the charging means to the filtering means is generally in alignment with the charging means, and said grounded metal plates extend through said duct means.

Claim 15

An electrostatic filter as defined in claim 10 including a plurality of substantially pArallel, grounded electrically conductive plates in said charging means, said plates extending in the direction of gas flow and subdividing said duct into channels to prevent an excessive space charge effect.

Claim 16

An electrostatic filter as defined in claim 13 including a plurality of wires in said charging means disposed in the channels between said plates and parallel thereto, and means for applying a high voltage to said wires, the channels being of width not more than four times the spacing between the wires and said plates.