The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 20, 2000
Filed:
Jul. 12, 1999
Kirk A Schneider, Eden Prairie, MN (US);
Henry J Drasner, III, Edina, MN (US);
Allan L Liebrenz, Excelsior, MN (US);
Katsushi Isogawa, Rosemount, MN (US);
Stanley Bucknam Miller, III, Eden Prairie, MN (US);
Paul Lawrence Kojetin, Rosemount, MN (US);
Cynthia D Bellefeuille, Eden Prairie, MN (US);
Andrew J Dallas, Apple Valley, MN (US);
Suzan K Nunnink, Delano, MN (US);
Donaldson Company, Inc., Minneapolis, MN (US);
Abstract
A filter is provided which includes an organic vapor adsorbing layer, a first particulate removal layer, and a second particulate removal layer. The organic vapor adsorbing layer includes porous adsorbent beads which allow air or gas to flow therethrough with little resistance and provide increased surface area by virtue of the pores. The particulate removal layer can be made from an electrostatic and/or polytetraflouroethylene. The filter can have a figure of merit greater than about 10 and a capacity for permanently adsorbing organic vapors, wherein the figure of merit is calculated based upon a fractional efficiency determined for particles having a size of 0.3 .mu.m in an air flow having a velocity of 10.5 ft./min and for Frazier permeability at 0.5 inches H.sub.2 O.