Improved tobacco smoke filters, particularly cigarette filters, are prepared from a web of synthetic polymeric fibers having applied to at least one surface thereof a film-forming derivative of cellulose. Continuous processes and apparatus for the production of the web and filter are also described.

This disclosure pertains to a filter apparatus utilizing a helically wound spring element adapted with a cap closing one end thereof. The other end of the spring is fed with the liquid or gas which is to be filtered. The spring may be permanently magnetized, or when electrically energized, be an electromagnet which magnetically constrains particles possessing magnetic properties within the chamber formed by the capped spring. The core of the spring may contain permanent magnets therein. The spri...

A self-supporting filter consisting of a plurality of fibre flakes distributed as fibre cells throughout a matrix. The matrix is preferably made of a porous material. The fibre flakes are agglomerations of short fibres. The filter is made by mixing fibre flakes and a binder, compressing the mixture in a mould and hardening the binder by a dry process to produce the matrix.

Disclosed herein is an improvement in a filter of the type having a plurality of filtering plates vertically spaced at fixed intervals to interpose filtering spaces therebetween and as many scrapers laid outwardly from the axis of the stack of filtering plates and inserted one each into the filtering spaces, i.e. between the adjacent filtering plates, the improvement which includes giving each filtering plate a perfectly circular periphery so as to avoid formation of any protuberance from the ci...

An upwash, upflow, graded sand filter has a reusable imperforate diaphragm on the top of the graded filter media and an inlet for pressurized fluid above the diaphragm for inflating the diaphragm against the media during filter stage. The filter housing is flared upwardly and outwardly at selected portions to reduce the velocity of upflowing liquid during wash stage for improved grading of the filter media. A natural foraminous layer may be self-grading at the top of the filter media, allowing a...

A rotary filtering apparatus having improved filtrate flow conducting means.

A filter for gaseous fluids comprises a housing having an inlet and an outlet for the gaseous fluid and containing a filter material which is disposed in at least two compartments arranged in series within the housing, with the face of each compartment opposite an adjacent compartment being at least in part defined by a permeable wall, and the facing permeable walls of two adjacent compartments being separated by an empty space.

A filter consisting of two endless belts of filter material pressed together.

A water faucet filter unit with means for selectively directing impure water either through a replaceable filter cartridge or bypassing the cartridge, directly out a dispenser opening of the filter unit.

Described herein is a porous filter mat comprising glass fibers and a quaternary ammonium silicate binder. Optionally, the mat contains asbestos or micro-glass fibers which reduce the porosity of the mat to the level required for the particular filtration. Filter elements made from the mat have good structural integrity even at high temperatures. The filter mat is used to remove particulates from the exhaust of an internal combustion engine.