Method for a fiber processing apparatus

• US 20020049564A1
• Filed: 11/27/2001
• Published: 04/25/2002
• Est. Priority Date: 01/25/1999
• Status: Active Grant

• Current Assignee: Dennis L. Konkol, Ola M. Johansson
• Original Assignee: Dennis L. Konkol, Ola M. Johansson
• Inventors: Konkol, Dennis L., Johansson, Ola M.
• Granted Patent: US 6,567,766 B2
• Time in Patent Office: Days
• US Class Current: 702/184
• CPC Class Codes: D21D 1/002 Control devices
• CPC Class Codes: D21G 9/0009 Paper-making control systems

Abstract

A system, software program, and method for monitoring performance of a fiber processing apparatus that preferably is a disk refiner or a filter screen that analyzes operating data pertaining to the operation of the apparatus to determine when a plate of the apparatus should be replaced before plate wear undesirably affects performance. Operating data over time is analyzed to determine whether it exhibits a trend characteristic of plate wear and, if so, a plate change recommendation is generated. In a preferred method, regression or piecewise linearization is utilized to determine a slope of the data and the slope is compared to a threshold. If above, below, or outside a certain value or window of the threshold, the recommendation is generated. To avoid fluctuations in performance not due to plate wear from affecting the determination, operating data over several hours of apparatus operation is analyzed. When a plate of an apparatus is changed, an inventory of the plates is updated. If the inventory requires replenishing, plates are ordered over a telecommunications link, such as by e-mail or FTP connection, with a remote supplier computer or system. New replacement plates can be entered into the inventory from information downloaded from a portable input device, such as a bar code scanner or the like.

Claims

1. In a computer system which monitors operation of a disk refiner or a filter screen, a method of estimating about when a plate of the disk refiner or filter screen that processes a fibrous slurry should be replaced comprising the following steps performed by the computer system:

a) receiving operating data pertaining to the operation of the disk refiner or the filter screen; and

b) analyzing a set of the operating data relating to a period of at least about two hours of operation to determine whether the plate of the disk refiner or the filter screen should be replaced.

2. A method of estimating about when a plate of a disk refiner or a filter screen should be replaced as recited in claim 1 wherein step b) comprises performing regression on the set of operating data to determine whether the plate of the disk refiner or the filter screen should be replaced.

3. A method of estimating about when a plate of a disk refiner or a filter screen should be replaced as recited in claim 2 wherein the regression performed comprises linear regression.

4. A method of estimating about when a plate of a disk refiner or filter screen should be replaced as recited in claim 3 wherein operating data relating to one of quality, tensile index, tear index, fiber length, shive content, freeness, bulk, fiber distribution, axial thrust load, specific energy, disk gap, dilution, amount of generated steam, vibration, and pressure differential pertaining to operation of the disk refiner is received in step a).

5. A method of estimating about when a plate of a disk refiner or filter screen should be replaced as recited in claim 3 wherein operating data relating to one of quality, tensile index, tear index, fiber length, shive content, freeness, bulk, fiber distribution, axial thrust load, specific energy, disk gap, dilution, amount of generated steam, vibration, and pressure differential pertaining to operation of the disk refiner is analyzed in step b).

6. A method of estimating about when a plate of a disk refiner should be replaced as recited in claim 3 wherein operating data relating to one of refiner motor power output, stock slurry flow, applied refiner plate force, refiner plate gap, dilution water flow, and consistency is received in step a).

7. A method of estimating about when a plate of a filter screen should be replaced as recited in claim 3 wherein operating data relating to one of stock slurry flow, pressure drop across the filter screen, consistency, and viscosity is received in step a).

8. A method of estimating about when a plate of a disk refiner or a filter screen should be replaced as recited in claim 1 wherein step b) comprises performing a piecewise linearization of the set of data.

9. A method of estimating about when a plate of a disk refiner should be replaced as recited in claim 1 wherein in step b) the set of the data comprises a set of data for a period of operation of the refiner of at least about one-hundred hours.

10. A method of estimating about when a plate of a disk refiner should be replaced as recited in claim 9 wherein in step b) linear regression is performed to determine a slope of a line fitted to the set of operating data versus time and a recommendation is made to change the plate of the disk refiner if the slope is negative in the direction of increasing time.

11. A method of estimating about when a plate of a disk refiner should be replaced as recited in claim 1 further comprising:

prior to step b) and about after when the plate is first installed on the refiner,

     1) threshold data is received over a period of time of refiner operation, and

     2) a threshold slope of a line fitted to the threshold data versus time is determined;

in step b) an operating slope of a line fitted to the set of operating data versus time is determined; and

a recommendation is made to change the plate of the disk refiner if the operating slope is not within about 10% of the threshold slope.

12. A method of estimating about when a plate of a disk refiner should be replaced as recited in claim 11 wherein the threshold data pertains to operation of the refiner for a period of time of at least about twenty-four hours after the plate is first installed.

13. A method of estimating about when a plate of a disk refiner should be replaced as recited in claim 1 further comprising:

prior to step b) and about after when the plate is first installed on the refiner,

     1) threshold data is received over a period of time of refiner operation, and

     2) a threshold slope of a line fitted to the threshold data versus time is determined;

in step b) an operating slope of a line fitted to the set of operating data versus time is determined; and

a recommendation is made to change the plate of the disk refiner if the operating slope is not within about 20% of the threshold slope.

14. A method of estimating about when a plate of a disk refiner should be replaced as recited in claim 1 further comprising:

prior to step b) determining a threshold slope pertaining to prior operation of the refiner with the plate installed; and

during step b) the steps comprising

     1) determining an operating slope of the set of operating data versus time and

     2) generating a recommendation to change the plate if the operating slope is not within about 10% of the threshold slope.

15. A method of estimating about when a plate of a disk refiner should be replaced as recited in claim 1 further comprising:

prior to step b) determining a threshold slope pertaining to prior operation of the refiner with the plate installed; and

during step b) the steps comprising

     1) determining an operating slope of the set of operating data versus time and

     2) generating a recommendation to change the plate if the operating slope is not within about 20% of the threshold slope.

16. A method of estimating about when a plate of a disk refiner should be replaced as recited in claim 15 wherein the set of operating data analyzed in step b) relates to a period of at least about fifty hours of refiner operation with the plate installed.

17. A method of estimating about when a plate of a disk refiner should be replaced as recited in claim 16 wherein the set of operating data analyzed in step b) relates to a period of at least about fifty hours of refiner operation with the plate installed.

18. A method of estimating about when a plate of a disk refiner should be replaced as recited in claim 17 wherein the set of operating data analyzed in step b) relates to a period of no more than about two hundred hours of refiner operation with the plate installed.

19. A method of estimating about when a plate of a filter screen should be replaced as recited in claim 1 wherein in step b) the set of the data comprises a set of data for a period of operation of the filter screen of at least about eight hours.

20. A method of estimating about when a plate of a filter screen should be replaced as recited in claim 19 wherein in step b) linear regression is performed to determine a slope of a line fitted to the set of operating data versus time and a recommendation is made to change a plate of the filter screen if the slope is negative in the direction of increasing time.

21. A method of estimating about when a plate of a filter screen should be replaced as recited in claim 1 further comprising:

prior to step b) and after the plate is first installed on the filter screen,

     1) threshold data is received over a period of time of filter screen operation, and

     2) a threshold slope of a line fitted to the threshold data versus time is determined;

in step b) an operating slope of a line fitted to the set of operating data versus time is determined; and

a recommendation is made to change the plate of the filter screen if the operating slope is not within about 10% of the threshold slope.

22. A method of estimating about when a plate of a filter screen should be replaced as recited in claim 21 wherein the threshold data is received over a period of time of at least about four hours of operation after the plate is first installed.

23. A method of estimating about when a plate of a filter screen should be replaced as recited in claim 1 further comprising:

prior to step b) determining a threshold slope pertaining to prior operation of the filter screen with the plate installed; and

during step b) determining an operating slope of the set of operating data versus time and generating a recommendation to change the plate if the operating slope is not within about 10% of the threshold slope.

24. A method of estimating about when a plate of a filter screen should be replaced as recited in claim 23 wherein the set of operating data analyzed in step b) relates to a period of no more than about ten hours of filter screen operation with the plate installed.

25. A method of estimating about when a plate of a filter screen should be replaced as recited in claim 23 wherein the set of operating data analyzed in step b) relates to a period of no more than about eight hours of filter screen operation with the plate installed.

26. A method of estimating about when a plate of a disk refiner or a filter screen should be replaced as recited in claim 1 wherein during or after step a) and before step b) the steps further comprising 1) storing at least some of the operating data, and 2) retrieving at least some of the stored operating data before performing step b).

27. A method of determining when a plate of a disk refiner or a filter screen should be replaced as recited in claim 26 wherein the computer system has a display and the recommendation is shown on the display.

28. A method of determining when a plate of a disk refiner or a filter screen should be replaced as recited in claim 1 further comprising:

1) storing an inventory of plates for a disk refiner or a filter screen;

2) updating the inventory; and

3) determining whether to order plates to add to the inventory.

29. A method of determining when a plate of a disk refiner or a filter screen should be replaced as recited in claim 28 wherein step 2) comprises:

i) scanning a tag of a plate containing information relating to identification of the plate wherein scanning is performed remotely of the computer system;

ii) storing the identification information;

iii) transferring the information relating to identification of the plate to the computer system; and

iv) adding the information relating to identification of the plate to the inventory.

30. A method of determining when a plate of a disk refiner or a filter screen should be replaced as recited in claim 29 wherein scanning is performed by a portable input device.

31. A method of determining when a plate of a disk refiner or a filter screen should be replaced as recited in claim 28 wherein if it is determined to order plates the following steps are performed:

i) linking with a supplier computer system that is located remote from the computer system; and

ii) submitting an order.

32. A method of determining when a plate of a disk refiner or a filter screen should be replaced as recited in claim 31 wherein during step i) linking is accomplished by a telecommunications link and during step ii) the order is submitted by e-mail.

33. A method of determining when a plate of a disk refiner or a filter screen should be replaced as recited in claim 31 wherein during step i) linking is accomplished by a telecommunications link and during step ii) the order is submitted by an FTP telecommunications link between the computer system and the supplier computer system.

34. A method of determining when a plate of a disk refiner or a filter screen should be replaced as recited in claim 28 wherein there are a plurality of the disk refiners or the filter screens and further comprising:

i) providing a record for each of the plurality of the disk refiners or the filter screens that stores each plate installed on each of the plurality of the disk refiners or the filter screens;

ii) updating the record for a particular one of the disk refiners or the filter screens when the plate is removed and a new plate is installed to reflect the plate removed and the new plate installed.

35. A method of determining when a plate of a disk refiner or a filter screen should be replaced as recited in claim 35 wherein during step 2) the inventory is updated to reflect the plate removed and the new plate installed and it is determined whether to determining whether to order a plate to add to the inventory in step 3).

36. A method of determining when a plate of a disk refiner or a filter screen should be replaced as recited in claim 35 wherein it is determined whether to order a plate to add to the inventory in step 3) after the record is updated in step ii).

37. In a computer system which monitors operation of a disk refiner or a filter screen having a plurality of pairs of sensors that sense data pertaining to the operation of the disk refiner or a filter screen, a method of determining when a plate of the disk refiner or filter screen that processes a fibrous slurry should be replaced comprising the following steps performed by the computer system:

a) monitoring the plurality of pairs of sensors to obtain operating data pertaining to the operation of the disk refiner or the filter screen;

b) storing at least some of the operating data;

c) retrieving at least some of the operating data;

d) determining a slope of a line fitted to a set of the operating data retrieved in step d); and

e) generating a recommendation to replace the plate if the slope is negative.

38. In a computer system which monitors operation of a disk refiner or a filter screen having a plurality of pairs of sensors that sense data pertaining to the operation of the disk refiner or a filter screen, a method of determining when a plate of the disk refiner or filter screen that processes a fibrous slurry should be replaced comprising the following steps performed by the computer system:

a) monitoring the plurality of pairs of sensors to obtain operating data pertaining to the operation of the disk refiner or the filter screen;

b) storing at least some of the operating data;

c) retrieving at least some of the operating data;

d) determining a slope of a line fitted to a set of the operating data retrieved in step d)

e) comparing the slope to a threshold slope indicative of normal operation; and

f) generating a recommendation to replace the plate if the slope is not within about 10% of the threshold slope.