Inertia filter

Claim 2

A filter assembly adapted to filter all fluid entering it and to operate at fluid velocities of at least 20 ft./sec. comprising, in combination, a housing having a head portion including an inlet and an outlet, a bowl portion; a plurality of filter plates disposed in the bowl; the filter plates having two filtering surfaces and an open flow passage therebetween communicating with the outlet; a filter plate support in the bowl supporting and positioning the filter plates in the bowl in a manner such that all fluid entering the bowl passes through the filter plates in order to reach the outlet; and a plurality of flow injectors in communication with the inlet in the head and adapted to constrain and direct fluid flow from the inlet to the filter plates at an impingement angle thereto of less than 30* and a velocity head loss across the orifice of at least 2 psi at a fluid velocity of at least 20 ft./sec., to provide an inertial flow component adjacent to and essentially parallel to and along the filter surfaces at a velocity that is at least ten times the velocity of flow through the filter plates, whereby contaminant particles are retained in the fluid flowing along the surface and lodging of the particles on the surface of the filter plates is inhibited.

Claim 3

A filter assembly in accordance with claim 1, in which the flow injector comprises a constricted passage in the support plate leading to the filter plates.

Claim 4

A filter assembly in accordance with claim 2, in which the constricted passage defines a nozzle.

Claim 5

A filter assembly in accordance with claim 1, in which the flow injector is at the inner end of an inlet passage in the support plate.

Claim 6

A filter assembly in accordance with claim 1, in which the filter plates are made of wire mesh.

Claim 7

A filter assembly in accordance with claim 1, including a sump in the bowl for receiving and collecting contaminant particles.

Claim 8

A filter assembly in accordance with claim 6, in which the sump, filters, and the bowl define a closed space on the upstream side of the filters, open only to the inlet, and on the downstream side of the filters open only to the outlet.

Claim 9

A filter assembly in accordance with claim 1, including a sump in the housing positioned beneath the filter elements for collecting and retaining contaminant particles swept along and from the filter.

Claim 10

A filter assembly in accordance with claim 1, in which the filter element comprises a plurality of parallel plate-like filters, each being formed in a closed configuration having an open central flow space, a spacer member positioned within the flow space of each filter so as to keep the central flow space open for flow; the support plate comprises upper and lower end plates supporting said plurality of plate-like filters in a spaced apart parallel relationship, and holding the filters together as a unit, said upper end plate engaging the housing so as to permit communication with the outlet only through the plate-like filter elements; and a plurality of orifices formed in the upper end plate and positioned between the plate-like filters, each orifice defining a passage for constraining flow and directing fluid flow from the inlet to the plate-like filters to maintain an inertial parallel flow component along the inlet surface of each filter.

Claim 11

A filter assembly in accordance with claim 9, in which the upper end plate has an annular wall positioned against the housing so as to seal thereagainst and direct all flow from the inlet within the wall, said orifices being positioned with the annulus defined by the wall so as to receive all flow from the inlet.

Claim 12

A filter assembly in accordance with claim 9, in which the bowl has a sump for collecting and receiving contaminant particles.

Claim 13

A filter assembly adapted to filter all fluid entering it and to operate at fluid velocities of at least 20 ft./sec., comprising, in combination, a housing having a head portion including an inlet and an outlet; a bowl portion; and at least two generally cylindrical filters concentrically disposed in the bowl with the inlet communicating with the interior of the intermost filter and via the interior of the innermost filter with the exterior of the outermost filter, which is spaced apart and distinct from said interior, and an annular filtrate flow passage between the filters communicating with the outlet, such that fluid passing through the assembly from the inlet to the outlet passes along the inner surface of the innermost filter element; and an annular flow passage adapted to constrain and direct fluid flow from the inlet at an angle of less than 30* only to the interior of the innermost filter elements filter surface, and maintain an inertial flow component adjacent to and essentially parallel to the filter surface and therealong at a velocity that is at least tent times the velocity of flow through the filter whereby the contaminant particles are retained in the fluid flowing along the surface and the lodging of particles on the surface of the filter is inhibited, and such fluid that does not pass through the innermost element reaches and passes along and through the outer surface of the outermost filter element.

Claim 14

A filter assembly adapted to filter all fluid entering it and to operate at fluid velocities of at least 20 ft./sec., comprising, in combination, a housing having a head portion including an inlet and an outlet; a bowl portion; and at least two generally cylindrical filters concentrically disposed in the bowl with the inlet communicating with the interior of the intermost filter and via the interior of the innermost filter with the exterior of the outermost filter, which is spaced apart and distinct from said interior, and an annular filtrate flow passage between the filters communicating with the outlet, such that fluid passing through the assembly from the inlet to the outlet passes along the inner surface of the innermost filter element; and an annular flow passage adapted to constrain and direct fluid flow from the inlet at an angle of less than 30* only to the interior of the innermost filter elements filter surface, and maintain an inertial flow component adjacent to and essentially parallel to the filter surface and therealong at a velocity that is at least tent times the velocity of flow through the filter whereby the contaminant particles are retained in the fluid flowing along the surface and the lodging of particles on the surface of the filter is inhibited, and such fluid that does not pass through the innermost element reaches and passes along and through the outer surface of the outermost filter element.

Claim 15

A filter assembly in accordance with claim 12 comprising three filters, of which two are arranged in series and are concentrically disposed in the housing within the third filter, with the annular filtrate flow passage therebetween.

Claim 16

A filter assembly in accordance with claim 12, in which the outermost filter element is of the depth type.

Claim 17

A filter assembly in accordance with claim 12 including a sump in the bowl for receiving and collecting contaminant particles.