7. MILL OPPORTUNITIES, PROBLEMS AND SOLUTIONS
7.1 MILL OPPORTUNITIES
Jim Oei, Western Pulp
1. Started chip thickness screening (CTS) in January and saw benefits in reduction of solids to Recovery, pulp strength and chemicals usage.
2. Optimizing Eop peroxide charge 70:30 split at present. 70% to inlet of Eop
reactor. 30% after Eop reactor.
3. Finished doing PINCH energy study with SP1.
4. Modified interlock to Eop M/C pump.
Marcel Gauthier, Weyerhaeuser
- 02 delignification start up next summer.
- Installed Diamondback chip bin.
- Double felt on pulp machine success.
- Problems getting rate in digesting. Resolved mid September.
- R-8 acid tank failed by-passed, no filters.
Gavin Baxter, Tembec-Skookumchuck
- Started up of a wood waste boiler in December, 2000 which enabled us to
shut down our natural gas fired boiler.
- Started up a 45 MW turbine in July. Now exporting power to the grid.
- Work on digester to increase washing and reduce Kappa variability.
- Recertified in ISO 14000 in April, 2001.
Ralph Lunn, Celgar Pulp
- New record production of 1,507 tons/day.
- New Fiberline Process Engineer.
- Blowline P.D. from Gold River (size 60) is being installed, also in blowline
position. Sandwell assisting with justification and modelling.
- Foxboro Delta V installed on our # 1 pulp machine, all of the mill now DCS
controlled.
- Torn titanium perf. plate on saltcake filter twice in past year. Looking into modification to design.
- Tear in aeration basin discovered about 2 weeks ago. Currently in process of
making an alternate treatment system (cooling pond becoming A.B., spill ponds
becoming a cooling pond).
- Project to use sesqui-sulphate in Bleach Plant almost complete.
page 2
Alain Bergeron, Kruger Wayagmack
- Dosage of chemical product to prevent scaling in digester heaters. Washing
frequency before: each 10 days. After dosage: none since 4 months.
Murray Walters, Harmac P & T
- Digester debottlenecking successful.
- Pulp MC Fourdrinier upgrade complete.
- Cl02 plant DCS conversion.
- H type flakt dryer rebuild.
- BSW realignment to allow 3rd line of 02 delignification.
Doug Robinson, Howe Sound Pulp & Paper
- Top felted 3rd press on pulp machine October 2000.
- Sand filters for R-8 hot water (replaces strainers).
Calvin Hastings, AMEC
- H.A. Simons has now become part of AMEC, a large U.K. based engineering and
construction company. The Simons name will no longer be used after 2001.
Michel Aucoin, Fjord Cell Inc.
- Sesqui to Evaporators successful.
- pH measurement in Eop stage is continuous.
- Trouble with Cl02 analysers at Do stage.
- Replace hot water in bleach washer to recirculate our bleach filtrate. We save
about 4,000 m3/day.
- Mud filter on continuous washing system.
Gerry Ferweda, Norske Canada
- On "A" bleach line at Crofton converted from 6 stage bleach plant to a 5 stage
DEopDepD with pre-washer. New MC Do stage also commissioned.
Don McCabe, Irving Pulp & Paper
- Continue to improve MBB performance, 15 20% below compliance.
- Sewering precipitator dust to MBB.
- Using new digester software.
- Pursuing 14000
- Environmental award received from government ministers.
page 3
Jean Bouchard, Paprican
- Paprican got a patent (US) on formaldehyde addition in Do.
- Very positive results from a member mill trial last September.
Mike Beattie, Weyerhaeuser, Dryden
- Mill recently completed upgrade to # 2 fine paper machine and construction of
Weyerhaeuser Learning Centre. Focus for the next 2 years will be construction
of the new Recovery Boiler.
- The main Fiberline Project for 2001 is the Sulphuric Acid project which will
modify acid addition/pH control on the Bleach Plant Do Stage.
7.2 MILL PROBLEMS AND SOLUTIONS
Rae Cunnington, Sandwell
Q. Has anyone recently installed a Tristar seal tank in their Bleach Plant?
A. No one at present.
Marcel Gauthier, Weyerhaeuser
Q. Cl02 tile tanks brick and mortar are failing. Does anyone know what
could be the cause? What procedure is used to get tank ready for
inspection?
A. Remove brick lining and inspect. Retile. 1000 gals with 100,000 gals. of water.
Rinse with hot water, flush and rinse.
Ralph Lunn, Celgar Pulp
Q. Anyone using spent acid in Bleach Plant? Specifically, sodiumsesqui
sulphate from SVP line or R-8. Issues? Problems?
A. Weyerhaeuser G.P. use on D1. No problems.
Tembec, Skookumchuck no problems.
HSPP Use on Do no problems.
Hinton Used to use it on Do.
Papers a couple of good papers out. One by Pat Bryant of EKA and another
by Tina Larson of Weyerhaeuser, Grande Prairie.
page 4
Ralph Lunn, Celgar Pulp (Contd)
Q. Who has experienced sheet delamination? How is it dealt with?
A. Terrace Bay experienced this.
Problems can be a result of press loading (Dave Theriault, Pope & Talbot).
Crofton may have seen this; unsure.
Alain Bergeron, Kruger Wayagamack
Q. Alkali analyser what is the best analyser? Kaeverner Metso, others?
A. Metso no people have it.
Kaeverner cell problem since installation 14 months. Ralph Lunn.
Use conductivity to control slaker.
Murray Walters, Harmac P & T
Q. Methanol Spill Response Plan?
A. Dilution, then transfer/disposal.
Dispersion/plume analysis has not been considered anywhere in North America.
Not considered a "significant hazard" on catastrophic failure.
Q. Who has microwave consistency transmitters?
A. Dryden does on Do feed, works good.
Espanola does.
BTG is selling lots.
Q. What are typical S02 Application Rates?
A. Woodfiber = 2 Kg/tonne,
Irving = 4 lbs./ton, Celgar = 0.4 Kg/tonne
Q. What caustic concentration are mills using in their Bleach Plant?
A. 5 to 20%.
Doug Robinson, Owe Sound Pulp and Paper
Q. Installing Cl02 heat exchanger (using Eo filtrate). Is anyone running a plate
and frame heater in Cl02 service?
A. Don McCabe, Irving Pulp & Paper use plate and frame with Cl02 (hot water
for heating). No problems really! Leaks may occur occasionally.
Committee survey was completed on this.
page 5
Stan Heimburger, Heimburger and Company
Q. Can H202 be used to efficiently destroy Cl02 in a Bleach Plant scrubber
stack? What are keys to control?
A. Domtar, Cornwall Ross Anderson will send info (check minutes from
Miramichi minutes). Mark Whalley may have info on H202 as scrubbing agent.
RX is slow!
Try metabisulfite or sulphite. Expensive though!
NCASI has publication on scrubbing mediums and chemistry. Murray Walters
will send info.
Michel Aucoin, Fjord Cell Inc.
Q. Im learning that the average discharge of BOD from foul condensate is
about 7 to 10 Kg/ton. Our mill is at about that, but we got problems of
odour. Our mill is in a 65,000 people city. What is the most efficient
way to reduce BOD and sulphur compounds from foul condensate?
A. We can dump H202 or 02 into the condensate. Also, we can split clean and
foul condensate. We can use ultrafiltration unit, stripper, reverse osmosis or a Bioreactor to treat it.
Q. Who is measuring or ever tried to measure Cl02 residual into D1 washers
vat?
A. LaTuque do that, but have a very short D1 retention time.
Q. Who is sending foul condensate directly to secondary treatment?
A. Pope and Talbot, Halsey do that without any pH adjustments Dave Theriault.
Groveton do that from Kris Kanters.
Gerry Ferweda, Norske Canada
Q. Cl02 Spill Containment Crofton proposal, 6 floors. Large berm / small
surface area (containment). Low dust-bagged / blanks of thiosulphate
(neutralisation), titanium line (prevention), mineral oil/sawdust (vapour
suppression). What are other mills doing?
A. Foam at Tembec, Skookumchuck.
6 high wall and above require gas testing in US (OSHA).
Contact E.B. Eddy.
Murray Walters to release/compile survey results.
page 6
Gerry Ferweda, Norske Canada (Contd)
Q. What do mills do to recover bed/energy from Bleach Plant effluent?
A. Boiler feedwater preheating.
Generator warm water for brown stock washing.
Heat exchanger on internal filtrate streams (concept).
Q. What do other mills do for pigeon control?
A. Don McCabe, Irving speakers with ferret music. Hung up owls. Pigeons will
migrate to other areas. Large nets. Spikes in roosting locations. Fiberglass
spikes.
Paprican had lab shutdown 8 months from pigeon droppings by ventilation
inlets.
Three people very sick 2 had to resign because of sensitivities.
Contact Dr. David Bird McGill University MacDonald Campus.
Q. What do other mills do for pH control?
A. Laurier extension filtrate sampler for pH use either air or water for back flush.
Mike Schofield, Hercules
Q. Sodium imbalance due to switch for NaOH to OWL in 02 delignification?
A. Skookumchuck no problems when switching.
Intercon no problem with switching.
Comment verify OWL charge on pulp re-verify calculations on Kg/TE basis.
Recalculate actual NaOH on EA charge not NaOH basis.
Dave Willis, FMC
Q. Is H202 residual test strip specific to peroxide?
A. Caren Caffrey. No need to use titanium oxalate or titanium sulphate, a
comparitor to distinguish whether the "oxidant" is H202.
Don McCabe, Irving Pulp & Paper
Q. Who has Cl02 meters on Bleachery stacks?
A. OPTEC very simple and works well. Howe Sound just started. Halsey uses
AMATEK. Gerry Ferweda EIT series 4000.
page 7
Don McCabe, Irving Pulp & Paper (Contd)
Q. Have to replace a vent scrubber close to condemnation. NB has no
regulations for Cl02 emissions. What are (if any) regulations for Cl02
stacks in concentration or rate?
A. Skookumchuck 39 ppm. Ralph Lunn 10 Kg/day. Murray 100 150 ppm.
Cold water scrubbing 150 ppm reasonable design.
Q. For the mills who use wire to wrap their bales what is the gauge and
tensile strength used?
A. 13 ½ gauge Murray.
Mike Beattie, Weyerhaeuser, Dryden
Q. What is the "tightest" screen slot that mills are using on their screen
baskets?
A. .008" seems to be about as "tight" as most mills have gone. Some mills have
tried .006", but have gone back to .008".
Gavin Baxter, Tembec-Skookumchuck
Q. What are mills using for D1 and D2 pH control ?
A. most mills are using NaOH. There are a few using
acid. Need special precautions to implement. Section in old bleaching
book on pH control.
Problems & Opportunities PAPTAC Bleach Committee Meeting Fall 2001.doc