Method of determining values of operating parameters of a centrifuge

• US 5,736,054 A
• Filed: 02/01/1995
• Issued: 04/07/1998
• Est. Priority Date: 08/13/1993
• Status: Expired due to Fees

• Current Assignee: Mannesmann Demag Krauss-Maffei AG (Siemens AG)
• Original Assignee: Krauss Maffei AG (Siemens AG)
• Inventors: Feller, Johann, Hegnauer, Bruno
• Primary Examiner(s): Reifsnyder, David A.
• Application Number:
  US08/381,755
• Time in Patent Office: 1,161 Days
• Field of Search: 210/739, 210/746, 210/787, 210/144, 73/649, 73/650, 364/801, 494/10, 494/37
• US Class Current: 210/739
• CPC Class Codes: B04B 11/043 Load indication with or without control arrangements
• CPC Class Codes: G01F 23/22 by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water involving the use of floats G01F23/30

Abstract

An operating parameter of a centrifuge is determined by converting vibration of the machine frame of the centrifuge on rotation of the drum thereof to electrical signals having a frequency spectrum which is analyzed. Variations of the peak amplitudes and frequency locations on frequency analysis, e.g. by Fast Fourier Transmissions, is used to signal the parameter, e.g. a parameter representing the degrees of filling the centrifuge, termination of filtration, etc.

Claims

1. A method of determining an operating parameter of a centrifuge selected from a degree of solids filling and a degree of liquid filling, comprising the steps of:

(a) supplying a centrifuge with a suspension of solids in a liquid, and driving said centrifuge to discharge liquid of said suspension and collect said solids;

(b) detecting vibration of said centrifuge resulting from rotation of a centrifuge rotor and producing electrical signals of a frequency and amplitude representing said vibration and having a frequency spectrum characteristic of operation of said centrifuge, presence and absence of said suspension, and characteristics of said liquid and solids in said centrifuge;

(c) subjecting said electrical signals to a frequency spectrum analysis and isolating from said frequency spectrum by said analysis a certain selected frequency; and

(d) determining said parameter selected from a degree of solids filling and a degree of liquid filling by evaluating a change in amplitude of said certain selected frequencies over a time interval.

2. The method defined in claim 1 wherein the frequency spectrum analysis is a fast Fourier transform analysis.

3. The method as defined in claim 2 wherein an amplitude of said certain frequency is compared with an amplitude of a predetermined frequency.

4. The method defined in claim 2 wherein steps (b) and (c) are repeated and a change in amplitude of said certain selected frequency is detected for determining said parameter.