Method for filtering liquids containing particles in suspension

[54] METHOD FOR FILTERING LIQUIDS

CONTAINING PARTICLES IN SUSPENSION

[75] Inventor: Cannelo Onandia, Vizcaya, Spain

[73] Assignee: Ona Electro-Erosion, SA., Spain

[21] Appl. No.: 376,232
[22] Filed: Jan. 23,1995

Related U.S. Application Data

[60] Continuation-in-part of Ser. No. 81,555, Jun. 23, 1993, abandoned, which is a division of Ser. No. 891,214, May 29, 1992, abandoned.

[51] Int. CI.6 B01D 21/32

[52] U.S. CI 210/739; 73/61.65; 73/61.69;

210/94; 210/123; 210/143; 210/745; 210/800

[58] Field of Search 210/94, 97, 121,

210/123.143, 242.1, 513, 739, 745, 776, 800; 73/61.63, 61.65, 61.68, 61.69

[56] References Cited

U.S. PATENT DOCUMENTS

39,565 8/1863 Gray . 275,134 4/1883 Burton 210/242.1

1,272,850 7/1918 Robbins .

3,341,983 9/1967 Baldenhofer et al. .

3,456,798 7/1969 Urdanoff.

3^51,330 12/1970 Jemqvistetal 210/745

3,693,795 9/1972 Robinson et al. .

3,812,966 5/1974 Beach etal 73/61.4

3,869,903 3/1975 Beach etal 73/61.4

3,897,335 7/1975 Brandt.

4,100,872 7/1978 Matsuno et al 210/242.1

4,876,881 10/1989 Pope 210/96.1

5,106,494 4/1992 Norcross 210/123

5,421,995 6/1995 Norcross 210/242.1

Primary Examiner—Joseph W. Drodge
Attorney, Agent, or Firm—Lucas & Just

[57] ABSTRACT

An improved system for filtering liquids containing particles in suspension, comprising a valve system for distributing liquid, a filter and a settling tank, in which the particles suspended in the liquid can settle during various phases at decreasing rates of settling, characterised in that a device are provided for emptying the top part of the settling tank and accompanying the liquid descending in the tank, the operation of the device being delayed for at least a part of the time corresponding to the phase of maximum speed of sedimentation.

2 Claims, 3 Drawing Sheets