Browse Prior Art Database

Paper Making Equipment Control

IP.com Disclosure Number: IPCOM000090647D
Original Publication Date: 1969-Jun-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 40K

Publishing Venue

IBM

Related People

Sullivan, PR: AUTHOR

Abstract

In this paper making machine, wire 10 moves over rollers 12 and on which a mixture of water and fiber or headstock 18 is deposited 16 from head box 14. The water and some fiber drains away leaving paper 20 at the end of wire 10. The drainage or silo stock 26 is fed back via 34 and combined at 36 with new main stock 42, having a high fiber concentration. The combined stock is pumped by 46 to headbox 14. Computer 54 is employed to determine and control the consistency of headbox stock 18. Measurements of the weight of the paper being produced W 27, main stock flow MF 50, main stock consistency MC 52, and combined headbox stock flow rate HF 56 are made and supplied to computer 54.

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Paper Making Equipment Control

In this paper making machine, wire 10 moves over rollers 12 and on which a mixture of water and fiber or headstock 18 is deposited 16 from head box 14. The water and some fiber drains away leaving paper 20 at the end of wire 10. The drainage or silo stock 26 is fed back via 34 and combined at 36 with new main stock 42, having a high fiber concentration. The combined stock is pumped by 46 to headbox 14. Computer 54 is employed to determine and control the consistency of headbox stock 18. Measurements of the weight of the paper being produced W 27, main stock flow MF 50, main stock consistency MC 52, and combined headbox stock flow rate HF 56 are made and supplied to computer 54. The latter determines headbox stock consistency HC by simultaneous solution of fiber balance equation (HF x HC) = (MF x MC) + (SF x SC) and empirical retention equation SC = HC(1-alpha)e/-gamma/(W). SF is the silo stock flow, SC equals silo stock consistency, alpha is the initial retention constant for a particular wire indicating the difficulty of water staying on the wire and gamma equals wire constant defining the loss or drainage characteristic for the particular fiber on the wire.

The computer, via digital-to-analog converter DAC, then sets control valve 40 to establish the main stock flow rate and thus controls the weight 27 of the paper 20 in accordance with the desired weight supplied as an input from input 55.

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