Method for pulp quality control and regulation

• US 5,076,890 A
• Filed: 02/27/1990
• Issued: 12/31/1991
• Est. Priority Date: 03/16/1989
• Status: Expired due to Fees

• Current Assignee: Dorr-Oliver Incorporated (Susanne Klatten, MBA)
• Original Assignee: Dorr-Oliver Incorporated (Susanne Klatten, MBA)
• Inventors: Balembois, Claude
• Primary Examiner(s): Fisher, Richard V.
• Assistant Examiner(s): Burns, Todd J.
• Application Number:
  US07/485,677
• Time in Patent Office: 672 Days
• Field of Search: 162/198, 162/258, 162/263, 162/DIG. 10, 162/DIG. 11, 73/61 R, 73/63, 417/900, 417/43, 417/12, 210/137, 210/96.1, 210/740
• US Class Current: 162/198
• CPC Class Codes: G05D 7/0635 by action on throttling means G05D7/0688, G05D7/0694 take precedence
• CPC Class Codes: Y10S 162/11 Wet end paper making variables

Abstract

The present invention relates to a method of qualitative and quantified monitoring of the instant local physical state of a substantially incompressible fluid material such as a liquid or pasty substance (for instance slurry or pulp) and a device for carrying out this method and the various applications and uses resulting from the working of the method and/or device for the automatic control of said physical state. The invention is also directed to the various equipment and systems provided with at least one such device.

Claims

1. A method for control of the consistency of a slurry or pulp fluid material proceeding from a sedimentation zone or thickener tank, comprising establishing a reference displacement time for a known volume of said fluid moving under a constant force or head load through a known distance, the displacement time being representative of a desired average state of consistency of said fluid volume, thereafter passing a known volume of said fluid under a constant head through said known distance, measuring the an actual displacement time of said volume of fluid consumed in moving through said known distance, calculating the difference between said reference displacement time and the measured actual displacement time, and adjusting the volume of moving fluid or the prior physical conditioning or elaboration of said fluid material to maintain or restore the desired average state of consistency.

2. The method of claim 1 wherein the reference displacement time and the actual displacement time, are the duration of the discharge stroke of a pump.

3. The method of claim 2 wherein the adjustment to maintain the desired average consistency of the fluid material is accomplished by changing the pumping speed or pumping cycle time.

4. The method of claim 1, 2 or 3 wherein computerized processing of the data is carried out with storage thereof and programming of operating steps to maintain or restore the desired average state of consistency.

5. A method for control of the consistency of a slurry or pulp fluid material proceeding from a sedimentation zone or thickener through a pipe line to a place of utilization or further treatment in an intermittently pulsed flow imparted by a reciprocating positive displacement volumetric pump in the pipe line having constant intake and discharge strokes and operating under a constant delivery head load, comprising operating the pump with a preset pumping cycle frequency to provide a predetermined output flow rate, determining a reference discharge time for the pump representative of a desired average state of fluid consistency, measuring an actual discharge time for the pump on each discharge stroke, comparing the measured actual discharge time with the reference discharge time to determine the corresponding time difference and adjusting the pumping cycle frequency governing the flow rate in the pipe line, or selectively varying the physical state in the sedimentation zone or thickener to alter the consistency of said fluid, until said time difference has been reduced sufficiently to restore the actual discharge time to correspondence with the reference discharge time and thereby reestablish the average state of fluid consistency in the pipe line.

6. A method according to claim 5, consisting in an automatic feedback control through computerized processing of stored data and programming of operating steps to maintain or restore the desired average state of consistency in said pipe line.