초록 ▼

An improved method is disclosed for cleaning a flow of gaseous fluid, such as room air, from particles present in the fluid, the gaseous fluid being ionized, and using a conductive grid placed across and upstream of the filter for protecting the filter from being charged by free ions. An air purifie

An improved method is disclosed for cleaning a flow of gaseous fluid, such as room air, from particles present in the fluid, the gaseous fluid being ionized, and using a conductive grid placed across and upstream of the filter for protecting the filter from being charged by free ions. An air purifier filter cartridge using the ion-intercepting grid of the invention is also disclosed. The grid may be connected to or electrically insulated from the ionizer ground potential, with equal effect.

대표청구항 ▼

1. In a device for removing particles from a flow of gaseous fluid, the device comprising,one of a continuously positive and a continuously negative high voltage source exposed within the flow of the gaseous fluid;a filter spaced apart from said high voltage source, said filter comprising a fine fil

1. In a device for removing particles from a flow of gaseous fluid, the device comprising,one of a continuously positive and a continuously negative high voltage source exposed within the flow of the gaseous fluid;a filter spaced apart from said high voltage source, said filter comprising a fine filter medium comprising fibers of untreated polypropylene, each fiber having a diameter on the order of approximately one micron and the average spacing between the fibers in the filter being about five to fifteen times the filter diameter, and said fibers being easily polarized when subjected to an electric charge; andsaid filter having no charging means other than said particles contacting said filter in said flow,the improvement wherein the device further comprises:an electrically-conductive, gas- and particle-pervious screen or grid extending across said fluid flow in the space between the high voltage source and the filter,whereby to improve the efficiency of the filter in removing said particles from said fluid flow by removing free ions from the fluid flow. 2. The improved device as defined in claim 1, wherein said fluid flow past said high voltage source has a velocity between 2 and 10 cm per second. 3. The improved device as defined in claim 1, wherein said high voltage source comprises a corona discharge means. 4. The improved device as defined in claim 1, wherein said high voltage source comprises a carbon fiber brush. 5. The improved device as defined in claim 1, wherein said grid or mesh is electrically grounded. 6. The improved device as defined in claim 1, wherein said grid or mesh is electrically isolated. 7. An improved method for cleaning a flow of gaseous fluid of particles present in said fluid, comprising the steps of:providing a high voltage source of continuous polarity for providing ions into said flow;setting a fine filter medium displaced from said source, said fine filter medium being comprised of electrically non-conductive fibers comprising untreated polypropylene, each fiber having a diameter on the order of approximately one micron and an average spacing among them of five to fifteen times the fiber diameter;setting an electrically-conductive grid substantially entirely across said flow between the voltage source and the filter medium, the grid being permeable to said flow and said particles;passing said fluid past said high voltage source, thereby charging said particles either positively or negatively without alternating between positive and negative charges;passing said charged particles through said grid and then through said filter medium, thereby removing free ions from the fluid onto the grid and avoiding effectively polarizing said fibers into a positive side and a negative side thereof without any net change in polarity of said fibers during said cleaning of said fluid; andadhering said charged particles to an oppositely-charged side of said fibers, said fibers being charged solely by said particles. 8. The improved method as defined in claim 7, wherein said grid is electrically grounded, for passing charges from said free ions to the ground. 9. The improved method as defined in claim 7, wherein said grid is electrically isolated. 10. An improved filter cartridge for an ionizing room air purifier which creates an air flow through the purifier, the cartridge comprising:an electrically nonconductive, fibrous filter media having two opposed faces, the fibrous filter media being comprised of untreated polypropylene fibers having average diameters on the order of about one micron, and the spacing among the fibers being five to fifteen times the fiber diameters;a container enclosing said media except at a path for said air flow through said media, from one face to the other; andan electrically conductive grid placed against one face of the filter media and held there by said container for use during filtering operation,whereby the grid may be placed in the flow to intercept ions not affixed to partic les in the air flow, to reduce charging of the filter media by such ions. 11. The improved filter cartridge of claim 10, wherein the cartridge includes means electrically connecting the grid to an electrical ground in the purifier. 12. The improved filter cartridge of claim 10, wherein the cartridge includes means electrically insulating the grid from any electrical ground in the purifier.