Low pressure drop deep electrically enhanced filter
First Claim
1. An electrically enhanced filtering apparatus, comprising:
- a layer of a porous filter medium folded into arms forming one or more pockets exhibiting a downstream side of said medium and with a base of said pocket open to an upstream side of said apparatus;
a first electrically conducting, perforated grid disposed over a first major exterior of said medium to cover said downstream side of each of said arms;
a second electrically conducting, perforated grid electrically separated from said first grid by said medium, disposed across a second major exterior of each of said arms on an upstream side of said medium; and
one or more electrodes separated from said upstream side of said medium, with said one or more electrodes spaced-apart from opposite corresponding ones of said arms while extending into at least one of said pockets and spaced-apart from said second grid.
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Accused Products
Abstract
A method and apparatus using deep pleated filters to provide efficient and safe electrically enhanced filtering (EEF), with ultra low pressure drop, higher efficiency of particulate removal and higher dirt holding capacity over the life of the filter. An EEF may be constructed with a housing, with or without an internal air moving device such as a fan, a deeply pleated filter, preferably a V-pack filter with sets of downstream ground electrodes and charge transfer electrodes borne by the exterior surface of the filter packs that form the filtering element. An ionizer assembly that ionizes the gas and charges particles entering the deeply pleated filter and also transfers a charge to the charge transfer electrodes on the filter pack. A plate seals the gasket on the filtering element against the ionizing assembly. A high electrical potential is applied to charging elements in the ionizer and, in some embodiments, a fan or motor assembly. The charge transfer electrodes enable the device to function with a high particle collection field between the charge transfer electrodes and the downstream grounded electrodes to safely and efficiently attain higher entrapment of the particles on the filter medium.
82 Citations
126 Claims
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1. An electrically enhanced filtering apparatus, comprising:
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a layer of a porous filter medium folded into arms forming one or more pockets exhibiting a downstream side of said medium and with a base of said pocket open to an upstream side of said apparatus; a first electrically conducting, perforated grid disposed over a first major exterior of said medium to cover said downstream side of each of said arms; a second electrically conducting, perforated grid electrically separated from said first grid by said medium, disposed across a second major exterior of each of said arms on an upstream side of said medium; and one or more electrodes separated from said upstream side of said medium, with said one or more electrodes spaced-apart from opposite corresponding ones of said arms while extending into at least one of said pockets and spaced-apart from said second grid. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 82, 83, 84, 92)
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25. An electrically enhanced filtering process, comprising:
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positioning across a flow of transient gaseous phase fluid, a porous filter medium and folded into one or more arms forming at least one pocket with each pocket closed at an apex on a downstream side of said arms and with a base of each pocket opening upstream sides of said arms to incidence of said flow; maintaining a first electrically conductive grid disposed along said downstream sides of said arms able to accommodate passage of the fluid from said medium; maintaining a second electrically conductive grid covering said upstream sides of said arms in a position spaced-apart from said first grid to accommodate said passage of the fluid, at a potential difference relative to said first grid; and locating one or more electrodes within said pocket at a location within the flow of the fluid, spaced-apart from said second grid, and disposed to transfer a charge onto said second grid. - View Dependent Claims (26, 27, 28, 29, 30, 94, 107)
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31. A filter for an electrically enhanced filtering apparatus, comprising:
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a layer of a porous filter medium folded into one or more arms forming a pocket with a terminus of said pocket located on a downstream side of said medium and with a base of said pocket open to an upstream side of said apparatus; a first electrically conducting grid disposed on an exterior of said medium to cover said downstream side of each of said arms and form an electrical connection with a common electrical conductor of said apparatus; and a second electrically conducting grid electrically separated from said first grid by at least said medium, disposed across the exterior of each of said arms within said pocket on an upstream side of said medium spaced-apart from other electrical conductors of said apparatus. - View Dependent Claims (32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 85, 95, 96)
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49. A filter for an electrically enhanced filtering apparatus, comprising:
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a layer of a porous filter mediumdisposed in a plurality of pleats within each of one or more of a plurality of arms, with said pleats undulating in succession, folded into said one or more arms forming a pocket with a terminus of said pocket located on a downstream side of said medium and with a base of said pocket open to an upstream side of said apparatus; an electrical conductor comprising a first electrically conducting grid disposed to cover pleats along said downstream side of each of said arms; and a second electrically conducting grid electrically separated from said first grid by said medium, disposed to extend across pleats along a second exterior of each of said arms on an upstream side of said medium and remain spaced-apart from other electrical conductors of said filter and said apparatus. - View Dependent Claims (50, 51, 52)
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53. An electrically enhanced filtering apparatus, comprising:
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a layer of a porous filter medium, folded into one or more arms forming a pocket with a terminus of said pocket located on a downstream side of said medium and with a base of said pocket open to an upstream side of said apparatus; a first electrically conducting, perforated grid disposed on an exterior of said medium to cover said downstream side of each of said arms; a second electrically conducting, perforated grid electrically separated from said first grid by said medium, disposed across the exterior of each of said arms on an upstream side of said medium; an electrode separated from said upstream side of said medium, with said electrode spaced-apart from opposite corresponding ones of said arms while extending through said pocket parallel to and spaced-apart from said second grid; and an electrical conductor spaced apart upstream from said electrode and said second electrically conducting grid, disposed to be maintained at a potential difference relative to said electrode. - View Dependent Claims (54, 55, 56)
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57. An electrically enhanced filtering apparatus, comprising:
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a layer of a porous filter medium disposed in a plurality of pleats undulating in succession and folded into one or more arms forming a pocket with a terminus of said pocket located on a downstream side of said medium and with a base of said pocket open to an upstream side of said apparatus; a first electrically conducting grid disposed on an exterior of said medium to cover said downstream side of each of said arms; a second electrically conducting grid separated from said first grid by said medium, disposed across the exterior of each of said arms on an upstream side of said medium; at least one electrode separated from said upstream side of said medium, with said electrode spaced-apart by a fixed distance from opposite corresponding ones of said arms while extending through said pocket parallel to and spaced-apart from said second grid; and an electrically conducting screen spaced apart upstream from said electrode and said second electrically conducting grid, disposed to be maintained at a reference potential difference relative to said first electrode. - View Dependent Claims (58, 59, 60)
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61. An electrically enhanced filtering process, comprising:
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positioning across a flow of transient gaseous phase fluid, a porous filter medium folded into one or more arms forming at least one pocket with a closed terminus on a downstream side of said medium and with a base of each said pocket opening upstream sides of said arms to incidence of said flow; maintaining a first electrically conductive grid disposed along said downstream side of said medium able to accommodate passage of the fluid through said medium; maintaining a second electrically conductive grid covering said upstream sides of said arms in a position spaced-apart from said first grid to accommodate said passage of the fluid, electrically separated from said first grid by said medium; maintaining a first potential difference between said second grid and said first grid by locating at least one electrode within said pocket at a location within the flow of the fluid, spaced-apart from and parallel to said second grid, and disposed to transfer a charge onto said second grid; and maintaining an electrically conducting screen spaced-apart upstream from said first electrode and said second electrically conductive grid, at a second potential difference relative to said first electrode. - View Dependent Claims (62, 63, 64, 65, 66, 86)
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67. An electrically enhanced filtering process, comprising:
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arranging a layer of a filter medium, into at least two folds to define a terminus between each pair of said folds on a downstream side of said layer when said layer is positioned across a flow of a gaseous phase fluid, and an open base on an upstream side of said layer opposite from each corresponding apex; disposing a first perforated, electrically conducting grid along exposed major surfaces of said folds on said downstream side of said layer; and positioning a second perforated, electrically conducting grid along exposed major surfaces of said upstream side of said layer, spaced-apart by said medium from said first grid and from other electrical conductors. - View Dependent Claims (68, 69, 70, 71)
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72. An electrically enhanced filtering process, comprising:
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arranging into at least two transversely oblique folds, a layer of a filter medium exhibiting first major exterior surfaces on an upstream side of said layer separated by a thickness of said layer from second major exterior surfaces on a downstream side of said layer to accommodate passage of gaseous phase fluids through said medium while trapping particles borne by the fluids; aligning a first electrically conducting grid with said folds along said second major exterior surfaces; and aligning a second electrically conducting grid maintained spaced-apart by said filter medium from other electrically conducting elements of said process, with said folds disposed along said first major exterior surfaces. - View Dependent Claims (73, 74, 75, 76)
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77. An ionizer for charging particles in an electrically enhanced ilter, comprising:
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a perforated screen of an electrically conducting material approximately defining a surface disposed across an opening to maintain a local reference potential;
an array of a plurality of spaced-apart electrically conducting electrodes extending across said opening with neighboring ones of said electrodes being separated and forming a plurality of gaps accommodating protrusion of alternate folds of a filter medium between said neighboring ones of said electrodes, while said electrodes lie between open bases and closed terminus of pockets formed by the folds while spaced physically apart from corresponding major surfaces of the filter medium; andan electrical insulator maintaining at least one of said electrodes spaced-apart from said surface. - View Dependent Claims (78, 79, 80, 81)
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87. An electrically enhanced filtering apparatus, comprising:
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a layer of a porous filter medium folded into arms forming one or more pockets with a terminus of said pocket located on a downstream side of said medium and with a base of said pocket open to an upstream side of said apparatus; a first electrically conducting, perforated grid disposed over a first major exterior of said medium to cover said downstream side of each of said arms; a second electrically conducting, perforated grid electrically separated from said first grid by said medium, disposed across a second major exterior of each of said arms on an upstream side of said medium; an electrode separated from said upstream side of said medium, with said electrode spaced-apart from opposite corresponding ones of said arms while extending through said pocket parallel to and spaced-apart from said second grid; and an electrically conducting screen extending across an inlet to said apparatus, establishing a first potential difference relative to said electrode, while a second potential difference occurs between said electrode and said second grid, and a third potential difference occurs between said second grid and said first grid. - View Dependent Claims (88)
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89. An electrically enhanced filter, comprising:
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a layer of a porous medium having a major first surface and a major second surface, folded into one or more pairs of arms each joined together at a terminus and defining a pocket included between pairs of said arms; an electrical conductor comprising a first electrically conducting grid extending across said arms of said first major surface; a second electrically conducting grid extending across said arms of said second major surface while maintained by said filter spaced-apart from other electrical conductors having an operational association with said filter; and at least one of said first grid and said second grid comprising a print of an electrically conducting material deposited upon a corresponding one of said major first surface and said major second surface.
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90. An electrically enhanced filtering apparatus, comprising:
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a layer of a porous filter medium, folded into arms forming one or more pockets with a terminus of said pocket located on a downstream side of said medium and with a base of said pocket open to an upstream side of said apparatus; a first electrically conducting grid coupled to a local reference potential and disposed over a first major exterior of said medium to cover said downstream side of each of said arms; a second electrically conducting grid electrically separated from said first grid by said medium, disposed across a second major exterior of each of said arms on an upstream side of said medium; an electrical resistance coupling said second grid to said local reference potential; and an electrode separated from said upstream side of said medium, with said electrode spaced-apart from opposite corresponding ones of said arms while extending through said pocket parallel to and spaced-apart from said second grid. - View Dependent Claims (91, 93)
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97. An electrically enhanced filtering apparatus, comprising:
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a layer of a porous filter medium folded into arms forming one or more pockets with a terminus of said pocket located on a downstream side of said medium and with a base of said pocket open to an upstream side of said apparatus, with said layer disposed in a plurality of undulating pleats within each of said arms; a first electrically conducting grid disposed at a local reference potential across a first major exterior of said medium to cover said downstream side of each of said arms; an electrode separated from an upstream side of said medium, with said electrode spaced-apart from opposite corresponding ones of said arms while extending through said pocket; a second electrically conducting grid electrically separated from said first grid by said medium, disposed across a second major exterior of each of said arms on an upstream side of said medium; and an electrically conducting screen disposed upstream of said electrode at said local reference potential and positioned to extend across an inlet to said apparatus and establish a first potential difference relative to said electrode, while a second potential difference occurs between said electrode and said second grid, and a third potential difference occurs between said second grid and said first grid. - View Dependent Claims (98)
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99. A filter for an electrically enhanced filtering apparatus, comprising:
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a layer of a porous filter medium folded into one or more arms to fit transversely across a passageway extending between upstream and downstream ports of the apparatus, with successive pairs of said arms alternately joined together to form a terminus and spaced-apart to form a pocket providing a base open to passage of effluent between the upstream and downstream ports; a first grid of an electrically conducting material conforming in shape to said medium to extend across each of said arms of said first major exterior surface; and a second, electrically conducting grid electrically disposed to extend in conforming shape across each of said arms of a second major exterior surface of said medium and remain in electrical separation from other electrical conductors operatively associated with said apparatus. - View Dependent Claims (100, 101, 102, 103, 104, 105, 106)
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108. A filter for an electrically enhanced filtering apparatus, comprising:
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a frame providing an inlet and an outlet; an electrical conductor comprising a first electrically conducting porous grid attached to said frame to extend across said inlet, with said first grid folded into one or more arms forming a pocket with a terminus of said pocket positioned within said outlet and with a base of said pocket positioned to open toward said inlet; and a replaceable media assembly removably insertably within said inlet, comprised of; a layer of a porous filter material folded into a geometric construct providing a downstream surface conforming in contour to said porous grid, receivable within said pocket to cover said arms of said first grid; and a second electrically conducting porous grid positioned in mating disposition with an upstream surface of said filter material in conformance with said contour to lie spaced-apart from other electrical conductors operatively associated with the apparatus. - View Dependent Claims (109, 110, 111, 112, 113)
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114. A filter for an electrically enhanced filtering apparatus, comprising:
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a frame providing an inlet and an outlet; a first electrically conducting porous grid attached to said frame to extend across said inlet, with said first grid folded into one or more arms forming a pocket with a terminus of said pocket positioned within said outlet and with a base of said pocket positioned to open toward said inlet; a replaceable layer of a porous filter material folded into a geometric construct providing an upstream surface exposed through said inlet and a downstream surface conforming in contour to said porous grid, removably receivable within said pocket to cover said arms; and a second electrically conducting porous grid removably insertable through said inlet and folded to conform to said contour of said upstream surface of said layer of filter material and cover said upstream surface of said filter material while remaining spaced-apart from electrical conductors operatively associated with the apparatus. - View Dependent Claims (115, 116, 117, 118)
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119. A filter for an electrically enhanced filtering apparatus, comprising:
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a replaceable media assembly, comprised of; a layer of a porous filter material folded into one or more arms forming at least one pocket with a terminus positionable toward a downstream side of the apparatus and a base of said pocket open toward an upstream side of the apparatus; a first electrically conducting porous grid disposed across said arms of said layer on a downstream surface of filter material; a frame accommodating removable insertion of said media assembly, with said first grid extending across a outlet of said frame; and a second electrically conducting grid formed into a geometric construct conforming in contour to an upstream surface of said filter medium to cover said arms within said pocket while spaced-apart from electrical conductors operatively associated with the apparatus. - View Dependent Claims (120, 121, 122, 123, 124)
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125. A filter for an electrically enhanced filtering apparatus, comprising:
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a layer of a porous filter medium disposed to form a fan-fold presenting a plurality of pockets open to an upstream side of the apparatus; a first electrically conducting grid conforming in shape to said pockets on a downstream side of said fan-fold and forming an electrical connection with a common electrical conductor of the apparatus; and a second electrically conducting grid conforming in shape to said pockets on an upstream side of said fan-fold, while remaining spaced-apart from other electrical conductors of the apparatus.
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126. A process of making a filter for an electrically enhanced filtering apparatus, comprising:
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disposing a layer of a porous filter medium to form a fan-fold presenting a plurality of pockets open to an upstream side of the apparatus; disposing a first electrically conducting grid conforming in shape to said pockets on a downstream side of said fan-fold to form an electrical connection with a common electrical conductor of the apparatus; and disposing a second electrically conducting grid conforming in shape to said pockets on an upstream side of said fan-fold, to remain spaced-apart from other electrical conductors of the apparatus.
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Specification