Method of determining filter pluggage by measuring pressures

• US 5,320,760 A
• Filed: 12/07/1992
• Issued: 06/14/1994
• Est. Priority Date: 12/07/1992
• Status: Expired due to Fees

• Current Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Frisbie, Elizabeth L., Wojcik, Robert E., Freund, Kenneth S.
• Primary Examiner(s): Drodge, Joseph W.
• Application Number:
  US07/986,450
• Time in Patent Office: 554 Days
• Field of Search: 28/104, 28/105, 28/167, 137/14, 210/90, 210/97, 210/143, 210/741, 210/340, 210/341, 340/606, 340/607, 340/608, 364/509, 364/510, 364/551.01, 364/558
• US Class Current: 210/741
• CPC Class Codes: B01D 35/12 Devices for taking out of action one or more units of multi- unit filters, e.g. for regeneration
• CPC Class Codes: B01D 37/04 Controlling the filtration
• CPC Class Codes: B01D 37/046 by pressure measuring
• CPC Class Codes: Y10T 137/0396 Involving pressure control

Abstract

A method to determine differential filter pressure caused by filter pluggage in a high pressure liquid system operated by a computer-operated control valve without the need for a pressure sensor coupled to the filter by corerlating the percent the control valve is open with the differential pressure of the filter. A signal is provided when the percentage of time the control valve is open exceeds a predetermined time and the filter is replaced in response to the signal.

Claims

1. A method for determining a pressure drop across a filter located between a jet and a pressure control valve that is connected to a pressurized liquid manifold with the aid of a computer to calculate percent openness of the valve and determine when to replace the filter, said method comprising:

a) obtaining a data set of manifold pressure, jet pressure set point, and the correlation between percent open and a corresponding flow factor of the pressure control valve;

b) providing the computer with a data base that includes the data set obtained in step (a);

c) programming the computer to calculate percentage openness of the control valve according to the following relationship;

##EQU2## wherein K₁ and K₂ are constants based on valve manufacturer provided characteristic plot of openness of the valve and resulting flow factor, GPM=gallons per minute, manifold psi=manifold pressure, filter psi=pressure drop across the filter and jet psi jet set point pressure signaling when said % valve the openness exceeds a predetermined value; and

replacing said filter in response to said signaling.

2. The method of claim 1 wherein K₁ is 28.52 and K₂ is 26.55.