US 3,959,140 AGranted

Filter especially intended for filtering natural water for the irrigation of cultivated fields

OwnerBertrand Leon Legrasinventor

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Abstract

The invention relates to an improved cleansable filter intended for filtering natural water for the irrigation of cultivated fields. The filter comprises a cylindrical body, a filtering element mounted inside said body and defining in the interior two concentric chambers, one communicating with the exterior through a drainage valve, and also through one of two lateral openings in the body. The other annular chamber encloses the first chamber and communicates with the exterior through the other lateral opening. The filter also comprises a brush mounted coaxially in said first chamber, said brush being rotatable manually or automatically from the exterior of the filter, and removing all foreign bodies from the inner wall of said first chamber. The liquid to be filtered enters the annular chamber through a lateral opening, passes into the first cylindrical chamber and through the filtering elements from the interior to the exterior, and leaves by the second lateral opening. The brush may be actuated manually by a crank-handle, the foreign matter being evacuated by opening the drainage valve. Alternatively, the brush may be driven by a device responsive to the pressure differences between the two chambers, the drainage valve being automatically opened at the same time. The filter and its constituent parts are designed so as to withstand pressures of the order of 10 bars without tearing or deformation.

A cleansable filter for filtering out of a liquid solid impurities, comprising

a. a body communicating with the exterior through two lateral openings and a drainage opening, the lateral openings including an inlet opening for entry of the liquid to be filtered and an outlet opening for discharge of the filtered liquid, the drainage opening being located at the lower end of the body and at the opposite end of the body from the inlet opening, and means for keeping the drainage opening temporarily closed;
b. a filter element mounted inside the body and defining in the interior of the body two concentric chambers, the first of the chambers communicating with the exterior through the temporarily closed drainage opening and through one of the lateral openings, the second of the chambers having an annular form and surrounding the first chamber and communicating with the exterior through the other lateral opening;
c. a brush located within the first chamber and actuatable from the exterior, and bristles on the brush adapted to sweep the internal wall of the filter element;
d. the liquid to be filtered passing into the filter through the inlet opening communicating with the cylindrical chamber and leaving the filter through the outlet opening communicating with the annular chamber, after having passed through the filter element from the interior toward the exterior;
e. the filter element being composed of three concentric cylindrical parts fitted one into the other, including
i. an innermost part comprising a mesh of stainless steel having pores at least one of whose sides measures at least 40 microns;
ii. an outermost part comprising a sheet of stainless steel having pores at least one of whose sides measures at least 6 millimeters;
and
iii. an intermediate part located between the said innermost and outermost parts and comprising a sheet of stainless material having pores at least one side of which measures at least five tenths of a millimeter;
iv. the said three parts being produced from substantially rectangular metal sheet and mesh, previously cut out on the flat and then rolled to the shape of a cylindrical sleeve, the lips of the mesh and the sheet being assembled by assembly means.

7 more elements

Abstract

Claims11