7 MILL OPPORTUNITIES, PROBLEMS AND SOLUTIONS
7.1 MILL OPPORTUNITIES
Guy Normandeau, DMI Peace River:
- Using evaporator condensate in the Bleach Plant. Result saved
$ 1,000,000/year of off-grade due to scale.
- Diamond rolls for chip screening.
- D, Eop, D, D, converting to 3 stage Bleach Plant in 2002 to use D1 stage as
an open wash stage, 18 Kg/t Õ 5 Kg/t.
- Down flow low solids on digester.
- On-line dirt scanner on the pulp machine.
Jim Collins, MPI:
- Have set several monthly and weekly production records this year.
- Now at 667 day LTA, 1,250,000 hours Safest Mill in Canada 2000.
- Kappa analyser added on blowline and into Bleach Plant Eop next.
- Inventory shut in March (2 weeks).
- W-55 (D2) washer drum replacement in process.
- Starting up FS200 fibre length analyser.
- Pulp machine upgrades new style steam coil about 2% AD increase.
- Trialling newest generation of enzymes.
- Trialled EKA conditions on R-8 for 5 6 weeks. Back to R-8 conditions.
- Continuing work on ISO 14001 registration.
Murray Walters, Pope & Talbot Harmac, BC:
- Installed/retrofitted bottom steaming to twin feed system Kamyr digester.
- Daken steam coils in Flakt "L" dryer.
- New drainage/vacuum table elements on pulp machine.
- Started DCS conversion of largest pulp machine (Delta V).
F. Munro, Domtar Espanola:
- Softwood Do stage converted from low consistency to medium consistency.
Commissioning delayed due to washer worm gear drive failure.
- Softwood oxygen reactor taken out of service due to stress corrosion cracking
initiated under fibreglass insulation.
- Replacing old Canron D2 washer vat with 254 SMO vat.
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David Flater, Norske Skog Canada Crofton, BC:
- # 2 Machine double-felted, 1st / 3rd process, partial DCS conversion (Delta V),
all foil table.
- Hog fuel Power Boiler precipitator rebuild, purchasing bark presses.
- K line brown stock washing new 13 1/2 x 20 Corrudek IV (was 11 ½" dia.)
- Cl02 storages, relined 88 vintage FRP storages.
Erik Tremblay, Metso Automation:
- Our new name is Metso Automation. It replaces Neles Automation. The PQM
analyser formerly with Sunds is now with Kajaani family.
Jim Hopmans, Sterling Pulp Chemicals:
- As of January, 2001, and from year 2000 (March), completed commissioning of
10 new or upgraded Cl02 plants in U.S. and Japan.
- Agreement reached with Northeast U.S. mill to install internet-based
supervisory control of their Cl02 plant.
- 2 recent plant awards India and China.
Lou Legall, Kimberly Clark Inc.:
- Implementing a new safety process (Safety and Loss Control Management)
September.
- Major shutdown items chemical at steam mixers in Eop, D1,
- 2 new pre-retention tubes (D1, D2), softwood chip thickness screening upgrade,
new drive on the pulp machine.
- Feasibility study for 2nd turbine generator. Have work completed on oxygen bleaching. Ready for appropriation preparation.
Eric Yee, Weyerhaeuser - Prince Albert, Saskatchewan:
- Prince Albert replaced 20 year old FRP Cl02 absorption tower to Ti-S3 with
sightglass on each tray.
- Since December, 2000, separated acid stream and enzymes stream. There is an increase in chemical savings. It seems acid deactivated enzymes.
- In the process of designing a new Eop storages feeding system.
- Using a newer model of Iogen enzymes EB. Can be 5oC higher.
Jeff Bennett, Canfor Prince George, BC:
- Paper machine speed up in progress, about 1/3 of way to goal.
- Production curtailed by about 10% in 1st and 2nd quarters of 2001.
- 2000 Shutdown delay 6 months to April 2001 (18 months from last shutdown).
- Installed new Mitsubishi headbox on paper machine, new economiser tubes
on # 2 Recovery Boiler. Installed 100 ft. of insulating brick inside refractory
of lime kiln, new falling film evaporator on-line in March, commissioned 165#
steam line between PG mill and Intercon mill.
- Recertified as ISO 9001 and ISO 14000 in March.
- Major capital program plans to reduce natural gas used for process steam
generation.
Dave Thiereault, Pope & Talbot:
- Start up of new R-8 generator in October.
- Converted Bleach Plant to DEop DoDP.
- Installed three new vacuum washers, 11.5 x 23 ft. Corrudek IV.
- Started up white liquor disc filter and new slaker/causticizers.
- Condensate hard piped to ASBs.
- Started up new turbotak scrubber.
Norm Liebergott:
- Controlling 02 or 00 stages for strength preservation.
- Add MgS04.
- Decrease temperature by 15oF before blowing.
- Do not add all the steam and oxygen in one mixer.
- For double 02 stages, a chelating stage before the 00 stage will prevent
strength loss.
Robert Jude, Pall Canada Limited:
- Recently started with Pall (14 months).
- Promote finer filtration (20 micron absolute) for filtering H2S04, NaCl03,
Ch30H and water.
- Presently working with Weyco Dryden on filtration of water for chlorate unloading
and acid.
Laurier Morissette, BTG Americas:
- New name BTG - Division of Spectris Technologies to BTG Americas Inc.
- Acquire Muetek specialised in wet end chemistry measurement and control,
and brown stock washing measurement.
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Ralph MacDonald, Alpac:
- Proceeding with digester downflow low solids.
- Added an additional flatbox on pulp machine.
- Investigating press upgrades.
- Energy conservation.
- Received ISO 14000 certification April 2001.
Stuart Scott, UPM Kymmene Miramichi:
- New company from Finland major restructuring.
- Replaced W-45 on spring shutdown.
- Started up pressurised screening system on Christmas 2000 shutdown.
- Pursuing ECF, doing longer runs.
- Looking at a pressurised 02 stage.
- Have been and will be taking more downtime for inventory adjustments
and market conditions.
Jean Bouchard Paprican:
- Changes in Management:
- New Research VP Dave MacDonald
- New Business VP Pierre Bourdages
- New Administration VP Hiring now.
Rodger Bernar Marsulex:
- Success with our outsourced FGD environmental services. Announced
15 year deals with BP Amoco Whiting, Santee Cooper and Syncrude.
- Western division acquired Westaims Chemical division December, 2000.
- Eastern division is being acquired by an Income Trust called Chemtrade
Logistics. Transaction expected by July, 2001.
Don McCabe, Irving Pulp & Paper Saint John, NB:
- New commissioned MBB (partial treatment 2 hours) now in compliance.
- Upgraded software digester DCS.
- New steam mixer, 02 mixer and TSP Eop stage.
- Continuous decoat system on precoat.
- Replaced tile in D2 repulper with duplex steel.
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Michael Aucoin, Fjordell Inc.:
- Optimisation phase of the start up of the mill. We got problem with
environmental compliance, confident to resolve it a the present shutdown.
- We are trying to find a better way to operate and control the mill.
7.2 MILL PROBLEMS AND SOLUTIONS
Guy Normandeau, DMI Peace River
Q. R-8 Saltcake use in Bleach Plant?
A. Eastern Paper currently uses in Do stages.
Leaf River currently uses saltcake.
Grande Prairie had corrosion problems when they tried it.
Q. High temperature Do stage?
A. Help for HexA removal.
Some papers out on high temperature Cl02.
Jim Collins MPI:
Q. Is anyone still using Pulmac Fiber Analyzer?
A. Irving, Crofton, Halsey
Marathon sheet former failed in process of putting out tester going to FS 200
analyser.
Q. Is there any work chloride removal for Bleach Plant effluent? Paprican
still working on?
A. Project on this is underway. Lab work underway. Project in Prince George
on recycle filtrate. Jean Bouchard Paprican can report on at future meeting.
Q. Within 2 week period after mill start in March, something clobbered our Do
Kajaani probe. Basically bend probes over 90o had to cut probe out each
time. Hi shear mixer checked out OK.
A. Generally opinion was pulp dewatered to form solid mass. Started up and
hit probes.
Rae Cunnington Sandwell:
Q. What have mills done to overcome nuisance ruptures of rupture discs on
Eop stages?
A. Crofton dont develop vacuum inside tower it weakens Rupture Disk so it blows at lower pressure.
Harmac follow installation instructions that come with rupture disks especially
torquing.
Provide DCS stop position on valve for S/D or program DCS to put valve w/open
when pump starts.
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Rae Cunnington Sandwell (Contd)
Q. What are filtrate recycle schemes for first two washers for mills that use
papricycle?
A. Prince Albert Do stage all Eop, P/C stage all hot water.
Terrace Bay Do stage hot water then Eop, P/C Stage hot water then
bleach white water.
Harmac Do stage all papricycle, P/C stage all hot water.
Murray Walters, Pope & Talbot Harmac, BC:
Q. Have any mills installed "sophisticated" wire cleaning showers on drum
washers?
A. None have. PG Pulp has started cycling their "drilled pipe" showers on a timer
to cut water usage.
Q. Have any mills considered/seen the GMS Kappa analyser from Thompson
Equipment?
A. No.
Q. Any mills using pressure screens instead of centrifugal cleaners for final
pulp cleaning?
A. E.B. Eddy does on slush feed to PMc. Irving has one screen acting as a barrier screen for 1 customer.
Q. Any mills have recently designed S02 absorption system?
A. Normally done in static mixer now, i.e., St. Anne Nackawic Pulp, PG Pulp
have in service.
Q. "Ratholing" in unbleached HD storage tank does anyone know a solution
to this problem?
A. Good dilution control is important. General consensus is that a much higher
zone is only solution, though not easy to achieve.
Q. Has anybody played with opening and closing any of the multiple nozzles
on a steam mixer?
A. No.
F. Munro, Domtar Espanola:
Q. Has anyone found a correlation between softwood pulp viscosity and pulp
machine runnability?
A. LaTuque found a correlation between viscosity long fibre and runnability.
Crestbrook noticed a correlation but could not prove anything.
F. Munro, Domtar Espanola (Contd)
Q. What slot size are mills running on slotted screens?
A. UPM Kymmene 0.008" slots.
Crofton 0.018" slots, 7 slots per inch, 0.008" slots, 7 slots per inch, 0.008" slots
Dryden 0.008" slots, 0.006" slots wedge wire.
Halsey 0.008" slots, continuous slot baskets.
David Flater, Norske Skog Canada Crofton, BC:
Q. Who has high methanol concentration to R-8 generator?
A. Bowater, Thunder Bay.
Lou Legall, Kimberly Clark Inc:
Q. Success with Advanced Control Systems in the Bleachery, i.e., enhanced
Kappa factor control benefits ($, quality improvement)?
A. Many successes References at Prince George, Lebel-Sur-Quevillion
Q. White liquor usage in the Bleachery to replace NaOH?
A. Skookumchuk use white liquor (partially oxidised) in their Eop. Committee
being formed to review white liquor use in the Bleachery.
Burton Branch Neill & Gunter:
Q. Ep Stage anyone adding MgS04 to this stage for viscosity protection?
A. 15% MgS04 is minimum needed.
Gord Homer has info on and recent presentation at Tappi Bleaching
Committee re use of MgS04. Will send a copy.
Eric Yee, Weyerhaeuser Prince Albert, Saskatchewan:
Q. Oxygen sparger at Eop stage premature crack. Pulp pluggage with
fibre. High pressure purge before installation world-wide.
Gord Homer has procedure to clean 02 sparger.
A. Kajaani not going to support Cl02 analyser. What mill has plan to this
problem.
Michael Aucoin, Fjordell Inc.:
Q. pH probe at the Eop stage?
A. Filtrex Pnet H202 residual (ORP). To est. this important. Conductive.
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Michael Aucoin, Fjordell Inc. (Contd)
Q. Does anyone use injection of H2S04 or sesquisulphate to the brown stock
washer?
A. C02 to improve drainage.
H2S04 watch for TRS (H2S), watch for lignin precipitation.
Gerry Pageau good paper PacWest few years ago.
Miramichi try on a spare evaps the product who can decrease the
viscosity of strong black liquor. It permits to increase the solids.
Tim Gilliss, St. Anne Nackawic, NB:
Q. Where are mills measuring pH on Do for ECF grades?
A. Shortly after Cl02 addition less than 3.0 pH target.
End of Cl2 tower in or near vat.
Before Cl02 addition target 2.5. More difficult to control pH after Cl02 addition.
Thurso 1 minute after Cl02 addition.
Q. Are any mills having success with a Cl02 tail gas analyser on their
Bleach Plant scrubber?
A. Espanola Brian Gartley to forward info.
Procal.
Amotech expensive.
Jeff Bennett, Canfor Prince George, BC:
Q. H202 control strategies on Eop and/or Ep stages. Currently use %
applied on both locations and can do Kajaani on Ep not totally
acceptable control when on Kajaani waste chemical when on % on
stock. What are mills using for sensors or strategies?
A. % on stock biased with upstream test entries.
BTG has a peroxide analyser.
Post Do kappa analyser feed forward control.
Compensate for production rate changes, grade changes.
Q. Alternatives to formaldehyde as indicator in liquor. A-B-C tests in Recaust
area/Digester area. Concerns about formaldehyde as a carcinogen
A. Scan method auto titrator.
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Jeff Bennett, Canfor Prince George, BC (Contd)
Q. Reversion prevention on short sequence bleaching (D Eop) going to
pulp machine. Come out pH 10+ from Eop washer. Pulp machine at
5 pH
A. Borohydride or S02 wash after Eop stage. Contact Jim Oei, Squamish.
Dave Thireault, Pope & Talbot:
Q. Do sulphuric acid addition point is to Cl02 solution. Heat caused Teflon
to melt at injection nozzle.
A. Should not add conc. sulphuric to Cl02 solution due to potential chlorate
formation. Might try diluting to 5% ahead of addition point, or separate addition
points.
Prince Albert had problem with stock flow control when added sulphuric
upstream.
Q. What is the typical difference seen between the Bleach Plant brightness
and the final brightness out of the dryer?
A. Marathon 1.2 points down, Irving 1.2 points down, Espanola 0.5 points down,
SW, 1.0 HW, Alpac 0.5 down, Terrace Bay 1.3 points up, Cariboo sees increase.
Lack of coolers tend to decrease brightness out of dryer, residual chemical
tends to increase brightness. Colour bodies in mill water can have major
impact depending on time of year.
Robert Jude, Pall Canada Limited:
Q. At Powell River, having an issue of cracking of the flanges on housing for
combined sodium chlorate and methanol. Is this a metallurgical problem?
A. Denis Owen the problem on the housing can also be the result of:
a) High temperature (80oC).
b) Control of concentrations of chemical.
c) Possible issues of poor welding penetration and high carbon welding rod.
d) Crystallisation of chlorate at weld imperfections helps to propagate the
cracking at weak weld points.
Ralph MacDonald, Alpac:
Q. AOX variation on Softwood. Does anyone have insight into AOX variation
other than Cl02 use and/or washing?
A. The mill raw water may contain AOX, can be more noticeable if "bogs" empty into
source water.
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Ralph MacDonald, Alpac (Contd)
A. Check wood supply.
Use of oil products in the wood delivery system.
Check NCASI literature.
Q. Acid/Cl02 addition and downstream pH control. How are mills controlling
pH and Cl02 addition?
A. Review location of pH probes. Most successful with pH probe after H2S04
prior to Cl02 addition.
Others with single pH measurement employ cascaded feedback control of
both H2S04 and Cl02.
Recycle of Do and Eop filtrates. PA Papricycle since 1992. Eop to Do shower.
Kamloops use Papricycle.
Stuart Scott, UPM Kymmene Miramichi, NB:
Q. Does anyone know anything about portable chillers?
A. Irvings Don McCabe to send information.
Bowater Kirsten Maki to send information.
Q. Need information on hardwood blends of chips to Kamyr digester.
A. Better opacity, better yield, St. Anne Norm Liebergott use it.
Q. Problem with residual probe on T-30 inlet. Very common problem for
probes.
A. BTG no known solution. Kajaani pH related. Marathon.
Q. Problem with chiller plugging with alum based material from water
treatment. Have brass tubes. Any chemical available to remove this
so it doesnt have to be cleaned mechanically?
A. Dennis Owen there is a mechanical way of doing it on a continuous basis.
Robert Jude use a sand based filter.
Dave Ryan, Irving Pulp & Paper Saint John, NB:
Q. How many mills use H202 in Bleached High Density? Is there any
viscosity loss depending on retention time?
A. On lab tests loss of 1 point. Crofton didnt test for viscosity loss as the
pulp is used on paper machine.
Q. Bird filter operation when using a doctor board. Has there been any effect
on wire life (SVP-HP)?
A. Need to refer to other people who have them in the industry.
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Jean Bouchard Paprican:
Q. Are mills experiencing corrosion problems in the headbox on the pulp
machine as a result of changing antichlor strategy from S02 in the D2
stage?
A. Nobody except Bowater, Thunder Bay has experienced corrosion. Pope
and Talbot (Halsey) are concerned and will check it at the next shutdown.
pH swing can be a problem without the use of antichlor.
Ted Tunstall, Pacifica Papers Powell River, BC:
Q. If anyone has experienced problems with MC standpipe dilution control
valves during start up> If so, what have you found helpful in resolving
this?
A. Depending on type of MC pump, the supplier provides a recommended
logic. There are dilution multiplier at bottom and dilution that can be
adjusted depending upon deviation from setpoint. Also, level is
fluctuating non-linearly first 50% is valve opening than it is pump
speed from 50 100%. Try 0 60 valve AO-100 pump.
A. Place them on manual.
Don McCabe, Irving Pulp & Paper Saint John, NB:
Q. How do mills automate their antichlor?
A. DMI residual probe on the discharge of D2. Try pH control. Murray Walters flow control.
Q. Who has an Eo stage above 100oC?
A. Kemira - Mills that do, have to for special reasons.
ANONYMOUS QUESTION
Q. Who is looking at Crofton style 02 stage ?
A. Harmac, KC Terrace Bay, 7 mills in North America