BENEFITS OF USING FLOW SCANNER IN THE COOKING PROCESS

Transcription

1 BENEFITS OF USING FLOW SCANNER IN THE COOKING PROCESS WOOD PROCESSING TECHNOLOGY SEMINAR, ARCACHON 26 APRIL 2018 HARVEY WASHBROOK, MANTEX

2 CHAPTER OVERVIEW FLOW SCANNER BENEFITS OVERVIEW WOOD YARD 06 MAINTENANCE 07 PAPER MACHINE 03 PRE-STEAMING 08 AMOUNTS 04 DIGESTER 05 RECOVERY CYCLE 2 / ANDRITZ WOOD PROCESSING SEMINAR / FLOW SCANNER BENEFITS APRIL 2018 / COPYRIGHT ANDRITZ

3 BENEFITS OF USING FLOW SCANNER Fiberline benefits FIBERLINE Washing & Bleaching Cooking Pulp Drying Digester Yield, Kappa stability Wood chip mixing REC.Bo Bleaching Paper machine Recovery cycle Production Woodyard Evaporation WLP & Recaustisizing 3 / ANDRITZ WOOD PROCESSING SEMINAR / FLOW SCANNER BENEFITS APRIL 2018 / COPYRIGHT ANDRITZ

4 BENEFITS OF USING FLOW SCANNER 1. Wood Yard FEED-BACK chip control - from two chip piles Under constant production level: By mixing chips from two (or more) different piles Can help maintain constant bone dry content Or Can help maintain constant moisture Sawmill + own chipped 4 / ANDRITZ WOOD PROCESSING SEMINAR / FLOW SCANNER BENEFITS APRIL 2018 / COPYRIGHT ANDRITZ

5 2. Pre-Steaming according to chip moisture. Poor pre-steaming Good pre-steaming Full of air, the chips float With the air properly removed, water enters the pores and the chips sink 5 / ANDRITZ WOOD PROCESSING SEMINAR / FLOW SCANNER BENEFITS APRIL 2018 / COPYRIGHT ANDRITZ

6 Pre-steaming chip moisture Poor pre-steaming Good pre-steaming Wherever there is air inside the chips, the cooking liquor will not be able to penetrate! 6 / ANDRITZ WOOD PROCESSING SEMINAR / FLOW SCANNER BENEFITS APRIL 2018 / COPYRIGHT ANDRITZ

7 4. Digester - Recipe for making pulp out of wood chips Time Temperature HEAT Chips from Woodyard MR. LIGNIN & Co. running to EVAP Chemicals from WLP 7 / ANDRITZ WOOD PROCESSING SEMINAR / FLOW SCANNER BENEFITS APRIL 2018 / COPYRIGHT ANDRITZ

8 Digester - Control strategy Normal way of controlling is to use FEED-BACK control principle. Doing corrections after measuring. Delay time in digester, Raw material changes before adjustments Uncertain cause and effect By using FEED-FORWARD control you will be one step ahead, predicting. Easier to optimize your process. Immediate cause and effect information Pulp Engineered Services Division / Technology Cross Training XT: Digester Systems, 8 th of November / ANDRITZ WOOD PROCESSING SEMINAR / FLOW SCANNER BENEFITS APRIL 2018 / COPYRIGHT ANDRITZ

9 Digester - Production control (continuous) Volume metric flow of chips Stable/ unstable Screw displacement + Rotor volume + Filling degree - Yield - Chip bulk density - Chip moisture - Rotation speed + PRODUCTION RATE Flow Scanner delivers exact chip consumption From wood yard to digester 9 / ANDRITZ WOOD PROCESSING SEMINAR / FLOW SCANNER BENEFITS APRIL 2018 / COPYRIGHT ANDRITZ

10 Digester - Usage for cooking control locations Scanner Dry mass flow, kg/s Moisture, % Object detection Production, adt/d Yield, % White Liquor Alkali charge Moisture % L/W ratio Object detection Removal of junk material / ANDRITZ WOOD PROCESSING SEMINAR / FLOW SCANNER BENEFITS APRIL 2018 / COPYRIGHT ANDRITZ

11 Digester - DRY CONTENT changes Changes over 1 day Hardwood pulp mill, 1000t/d, Yield 56% Bone Dry mass Flow 75,000 Kg/h Target EA charge 15.3% Typical BONE DRY variation 2-10% per day Consider 3% decrease of material. Bone Dry content now 72,000 Kg/h EA charge = EA amount/dry content EA charge goes to Overcharge of approx. 0,47% Yield = - 0,25% Hardwood, -0,1% Softwood This situation occurs 40% of production = 350 extra tons pulp in the blow tank / year. Reduced production by tons/year 12 / ANDRITZ WOOD PROCESSING SEMINAR / FLOW SCANNER BENEFITS APRIL 2018 / COPYRIGHT ANDRITZ

12 Digester chip moisture changes Liquor-to-Wood L/W-ratio 4,0 3,9 3,8 3,7 3,6 3,5 3,4 3,3 Softwood kappa 30 Production 1200 adt/d Yield 46,5% EA charge 20% on wood 20% EA strength 120 g/l (NaOH) Prodution days 354 /year Influence of chip moisture on L/W ratio L/W-ratio 3,5 in feeding Batch Packing degree Batch & continuous Effects EA charge Evaporation Gas Phase Continuous: Effects chip column weight = cooking Speed = Kappa. Steam consumption 3,2 3,1 3, Chip Moisture [%] Solution Stabilize with EA charge adjustment and black liquor amounts L/W ratio digester 13 / ANDRITZ WOOD PROCESSING SEMINAR / FLOW SCANNER BENEFITS APRIL 2018 / COPYRIGHT ANDRITZ

13 Digester - Chip moisture changes Typical short term variations in moisture 48% - 55% common short term range 3-5% over few days (Europe) Kappa variation of 4-5 units Larger changes occur Continuous variation in moisture Moisture increase: = undercook 3 Kappa Moisture decrease: = overcook 2 Kappa Impact of chip moisture on kappa - softwood - Models developed by 3 rd party based on mill data and Pulping System Modelling Program, University of Washington, USA If correct for lower moisture only (40% of production) Regulate BL and WL for constant L2W ratio 1 Kappa = 0,5% Hardwood, 0.15% Softwood 1000ADt/d = extra 1400 Adt/y HW or 500 Adt/y SW 14 / ANDRITZ WOOD PROCESSING SEMINAR / FLOW SCANNER BENEFITS APRIL 2018 / COPYRIGHT ANDRITZ

14 Digester control Dry Mass and moisture variations Low Kappa data Low dry mass Low moisture Improvement gives higher Kappa High Kappa data High dry mass High moisture If uncorrected keeps high yields Only correct when so high would cause further fiberline losses. Consequence average Kappa increase improved yields without further costs. 16 / ANDRITZ WOOD PROCESSING SEMINAR / FLOW SCANNER BENEFITS APRIL 2018 / COPYRIGHT ANDRITZ

15 5. Recovery cycle - White Liquor savings K from overcharge results in much greater EA with resulting loss of yield and stress on recovery cycle. Non-linear relationship Kappa Undercharge Overcharge Target Kappa Over charge and under charge do NOT cancel each other out Extra WL requires more energy to Lime Kiln Cooking liquor (%) 17 / ANDRITZ WOOD PROCESSING SEMINAR / FLOW SCANNER BENEFITS APRIL 2018 / COPYRIGHT ANDRITZ

16 Recovery cycle - White liquor savings Savings in white liquor which can be converted to more production Available production increase in blow line /year Softwood kappa 30 Production 1200 adt/d Yield 46,5% EA charge 20% on wood EA strength 120 g/l (NaOH) Production days 354 /year Overcharging of 0,1% EA overcharge saving 30% of the year. EA reduction 0.1% = 1500 tons/year % of production days with overcharging WL [% av 354 days] Overcharging of WL 0,5% EA Overcharging of WL 1,0% EA 18 / ANDRITZ WOOD PROCESSING SEMINAR / FLOW SCANNER BENEFITS APRIL 2018 / COPYRIGHT ANDRITZ

17 Digester control - Cooking model improvement Known material properties inside the digester - Dynamic yield calculations = better process knowledge. Christoph Storz, Technology director, Schweighofer Fiber Greater knowledge means better cooking model design Better model implementation for best cooking design. 19 / ANDRITZ WOOD PROCESSING SEMINAR / FLOW SCANNER BENEFITS APRIL 2018 / COPYRIGHT ANDRITZ

18 Foreign Objects detection (manual removal) High pressure feeder Chip conditioning segments High pressure feeder breakdown Downtime: 51 hours Production loss: 1788 adt Rebuild cost: EUR Rule of thumb? 1000t/d pulp mill. 1 day stop = $500,000 loss of production 21 / ANDRITZ WOOD PROCESSING SEMINAR / FLOW SCANNER BENEFITS APRIL 2018 / COPYRIGHT ANDRITZ

19 7. PAPER MACHINE Higher strength Faster water drainage Stable viscosity Increase paper machine speed Reduce fibre consumption, maintain strength 22 / ANDRITZ WOOD PROCESSING SEMINAR / FLOW SCANNER BENEFITS APRIL 2018 / COPYRIGHT ANDRITZ

20 8. AMOUNTS As observed or calculated for pulp mills using FLOW SCANNER White Liquor savings, increased yields, energy savings (3% reduction - $200k $1M/year) (based on reported monthly savings at mill in Poland) Increase 1 target Kappa. (Hardwood = 0.7% yield = 2100 tons = >$750k) (Eucalyptus mill calculation). Target kappa increase at softwood pulp mill. Reduced bottlenecks 15 days/year where recovery cycle limits production 0,5-1% ( more tons = $500k-$1M) - Using Andritz formula. Others (less stops, improved pulp quality)? Reduced virgin fibre at paper machine? (3% = additional $1M)? 23 / ANDRITZ WOOD PROCESSING SEMINAR / FLOW SCANNER BENEFITS APRIL 2018 / COPYRIGHT ANDRITZ

21 LEGAL DISCLAIMER ANDRITZ AG 2018 This presentation contains valuable, proprietary property belonging to ANDRITZ AG or its affiliates ( the ANDRITZ GROUP ), and no licenses or other intellectual property rights are granted herein, nor shall the contents of this presentation form part of any sales contracts which may be concluded between the ANDRITZ GROUP companies and purchasers of any equipment and/or systems referenced herein. Please be aware that the ANDRITZ GROUP actively and aggressively enforces its intellectual property rights to the fullest extent of applicable law. Any information contained herein (other than publically available information) shall not be disclosed or reproduced, in whole or in part, electronically or in hard copy, to third parties. No information contained herein shall be used in any way either commercially or for any purpose other than internal viewing, reading, or evaluation of its contents by recipient and the ANDRITZ GROUP disclaims all liability arising from recipient s use or reliance upon such information. Title in and to all intellectual property rights embodied in this presentation, and all information contained therein, is and shall remain with the ANDRITZ GROUP. None of the information contained herein shall be construed as legal, tax, or investment advice, and private counsel, accountants, or other professional advisers should be consulted and relied upon for any such advice. All copyrightable text and graphics, the selection, arrangement, and presentation of all materials, and the overall design of this presentation are ANDRITZ GROUP All rights reserved. No part of this information or materials may be reproduced, retransmitted, displayed, distributed, or modified without the prior written approval of Owner. All trademarks and other names, logos, and icons identifying Owner s goods and services are proprietary marks belonging to the ANDRITZ GROUP. If recipient is in doubt whether permission is needed for any type of use of the contents of this presentation, please contact the ANDRITZ GROUP at welcome@andritz.com. 24 / ANDRITZ WOOD PROCESSING SEMINAR / FLOW SCANNER BENEFITS APRIL 2018 / COPYRIGHT ANDRITZ