31 0 6MB
Center for Wood Sciences
CASWoodͲBased Panels Module1:Process Technology
Particle generation Prof.Dr.JoergB.Ressel September7Ͳ 12,2015– Biel,CH
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
Wood-Based Panels
Content
Particle Generation • Particle generation • Particle generation – conversion paths • Log debarking – drum and ring debarker • Flake generation for PB • Crusher – pre-breaker • Drum chipper • Impact hammer shredder • Impact hammer mill • Knife ring flaker • Drum flaker • Hammer mill • Prallfiner – impact mill – sieve ring mill • Waste wod processing
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
• Strand generation for OSB • Long log ring flaker • Knife ring flaker • Fibre generation for MDF • Defibration process steps • Refiner and refiner plates • Refiner – additional equipment
Wood-Based Panels
Particle generation
Raw materials (summarised) Logs – round wood Æ forests (industrial wood Æ timber harvest) Forest residues Æ forest management actions (thinnings), small diameter logs, large branches … Residual wood Æ by-products from primary wood processing …
Round Wood
Slabs, sidings, off-cuts Chips (Æ chipper-canter lines), shavings Sawdust Peeler cores Veneer residues
Reclaimed wood – waste wood Æwithout chemical pre-treatment, packaging materials, demolition wood Agricultural residues / annual plants … seasonally harvested ! Æ cereal straw, bagasse, rice husks … plantation residues Æ rubber wood, palms Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
Sawmill Residues
Straw
Industrial Wood
Reclaimed Wood
Wood-Based Panels
Particle generation
Conversion of raw materials Æ Particle generation Depending on the raw materials used particle generation is done stepwise; often interrupted by screening and cleaning steps. Screening Æ output fractions are: Fines fine particles … dust Æ energy generation Accepts Overs
Chips
convenient particles Æ panel production oversized particles Æ chopped up again
Impurities removed particles (metals, soil, sand, stones, knots ...) to avoid any damage to processing equipment and panel milling machinery Storage bunkers and bins ensure continuous material supply. Material transport occurs by suitable conveying and feeding systems particle generation by …
(Maier 03/2005)
MRZ knife ring flaker MSZ beating flaker MPF prallfiner (mill type) MPM impact mill
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
Impurities (removed)
Strands (from logs)
Flakes MRZ
Beaten flakes MSZ
Fine flakes MPF/MPM
Wood-Based Panels
Particle generation
Conversion paths to achieve suitable particles for typical WBPs Specific particles, e.g., for OSB, PB and MDF, and different raw materials require customized process technologies to achieve an optimal result. The chart shows some alternative conversion paths without intermediate screening, grading, storage and further disintegration of particle fractions. Round wood, long logs
Chips Slabs, off-cuts (Sawmill by-products) (Sawmill residues)
Round wood, short logs ...
Reclaimed wood Waste wood Crusher (Prebraker)
Debarking
Cut to length
Direct flaker (KRF)
Drum flaker
Process technology
Product Output
Impact mill
OSBStrands
PB flakes
PB flakes
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
Chips
Debarking Drum chipper (OSB)
Drum chipper
Wood Preparation Raw material - Input
Round wood, logs
Sawdust (Sawmill residues)
OSB chips
Knife ring flaker
Prallfiner
Impact mill
Strand flaker
PB flakes
PB flakes
PB flakes
OSBStrands
Drum chipper
Chips
Refiner
MDF Fibres
Wood-Based Panels
Particle generation
Conversion paths to achieve suitable particles for typical WBPs Specific particles (Æ flakes) for Particle Board
Round wood, long logs
Chips Slabs, off-cuts (Sawmill by-products) (Sawmill residues)
Round wood, short logs ...
Reclaimed wood Waste wood Crusher (Prebraker)
Debarking
Cut to length
Drum chipper
Drum flaker
Raw material - Input Process technology
Product Output
Impact mill
PB flakes
PB flakes
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
Sawdust (Sawmill residues)
Chips
Knife ring flaker
Prallfiner
Impact mill
PB flakes
PB flakes
PB flakes
Wood-Based Panels
Particle generation
Conversion paths to achieve suitable particles for typical WBPs Specific particles (Æ strands) for Oriented Strand Board
Round wood, long logs
Round wood, short logs ...
Slabs, off-cuts (Sawmill residues)
Reclaimed wood Waste wood
Debarking
Cut to length
Raw material - Input
Direct flaker (KRF)
OSB chips
Strand flaker
Process technology
Product Output
Drum chipper (OSB)
OSBStrands
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
OSBStrands
Wood-Based Panels
Particle generation
Conversion paths to achieve suitable particles for typical WBPs Specific particles (Æ fibers) for Medium Density Fibreboard (MDF … HDF)
Chips (Sawmill by-products
Round wood, logs
Debarking Drum chipper
Raw material - Input Process technology
Product Output
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
Sawdust (Sawmill residues)
Chips
Refiner
MDF Fibres
Wood-Based Panels Conversion of raw materials
Particle generation i.e. the raw material recipe
Production step preferably starts with … A more or less constant blend of raw material sorts, particularly related to different wood species to ensure uniform panel properties at the end of the overall process. Debarking, only required for high quality, bright surface layers; for core layer particles rough debarking during timber harvesting is sufficient; most bark particles will be removed later during various screening steps preferably after the particle drying. Raw material cleaning (wet or dry log or chip cleaning, dust/sand/soil removal). Metal detection and removal of contaminated pieces and contaminants.
Particle dimensions (… the required pre-product of this production step) The first flaking process determines particle length and thickness; particle thickness - unlike length and width of a particle - cannot be changed anymore in following process steps! Î Particle slenderness: length to width ratio (Ɛ/w-ratio) Î Particle size and shape (geometry) influence resin consumption, mat densification behaviour, and panel properties, e.g., thickness swelling, MOE, MOR … Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
Wood-Based Panels
Particle generation
Log debarking Round wood or logs are either debarked separately or as a bunch of individual stems. Debarkingofabundleoflogs
Debarkingofindividuallogs
Simultaneously,continuouslyor batchwise Drum debarker
o
Ring debarker
Rotary or cradle debarker
o
Flail debarker 1
o
Rosserhead debarker 2
Mobile debarker 3 1 2 3
Debarking by means of rotating chains Debarking by means of rotating cutter head Debarking machinery installed on a mobile platform
1, 2
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
… without any importance for WBP industry
Wood-Based Panels
Particle generation
Rotary debarker Æ dry multiple stem debarking Fixed tub (trough) assembly containing pairͲwise openings in the bottom with rotors equipͲped with debarking plates; rotating plates cause the logs to spin and to hit each other
http://www.fujikogyo.co.jp/HP-English/king/barker/ crosssection20080327.jpg / 23.08.2011
Debarker is installed at a declined angle, enͲsuring continuous log movement towards the discharge end during debarking
Rotor Debarking plate Slit Fixed drum Rotor
Fuji Kogyo 2005
(http://www.fujikogyo.co.jp/HP-English/king/barker/crosssection20080327.jpg / 12.08.2015)
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
Movement of logs [ ] Rolling – rotating of each log on its own axis [ ] Rocking – bouncing up and down of each log [ ] Rotating – rotation of the entire batch of logs
Wood-Based Panels
Particle generation
Rotary debarker SAVICO, QC/CAN Debarking depends on
Wood specie + age, Log shape, Log dimensions, Operating temperat., Bark retention, Accept. fibre loss
three rotors ! (http://www.savico.com/en/debarker.html / 12.08.2015)
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
12 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Rotary debarker FUJI Kingside Debarker Outfeed Æ cleaning belt Æ chipper
(http://iem.ca/images/forestry-projects/upm_blandin_project.jpg / 12.08.2015)
http://www.fujikogyo.co.jp/HPEnglish/king/barker/kingbarker.html / 12.08.2015)
Debarking tools, shape depending on wood species / bark type; mounted on the rotor
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
13 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Drum debarker Stationary plant with rotating drum, feeding devices and adjustable discharge gate Drum dimensions: length 6…60 m, diameter 3…4.5 m; (Æ recommended ratio log length / drum diameter is < 0.7) Debarking capacity up to 350 m3 h-1 ÅÆ rotary debarker 5…30 m3 h-1 Continuous or batch-wise feed-in of logs Processing either tumbling mode or parallel mode (log length > drum diameter) Low wood losses (log breakage and “brooming” of log ends) Achievable cleanliness 1 % remaining bark Additional equipment: o Particular infeed system, including optional de-icing station ahead (infeed conveyor) o Bark separation section integrated in outfeed conveyor Parallel mode o Integrated process control Tumbling mode
Metso panelboard 2005 Andritz 2002
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
14 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Drum debarker Bark removal slots Drive unit Debarking drum Housing
Pallmann PDD Technical data Drum diameter Drum length Log length Capacity
3–5 m 12 – 32 mm 1–8 m 40 – 350 m³ h-1 Discharge gate
Fulghum Drum Debarker [0:13 m]
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
Pallmann 2011
Bark removal conveyor 15 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Ring debarker Debarking of single logs by passing trough a rotating ring, equipped with curved, scraping-tipped tools. Tools are pressed against the fed logs by particular devices (springs, rubber bands, hydraulic, pneumatic pressure elements). Special tools available for particular debarking challenges, e.g., stringybark, thick, fibrous bark Æ Eucalyptus ssp.
Principles of ring debarking / debarking knife (Fronius 1989)
Rotation speed is 90…450 min-1, feeding speed is 20…60 m min-1. Ring debarkers are equipped with either one single debarking ring or as tandem debarker carrying two successive rings.
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
Debarking ring and pressure elements Æ variable pressure air seal, bellow and air cell (Nicholson 2004) 16 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Ring debarker
VK Air Seal Debarker (Valon Kone 2015 – 2:30 min)
Formax™ replaceable debar-ker tool arms and tips
VK5000HD-Combi-2R VK tool for stringybark logs
(http://www.valonkone.com/media/images/2R%20new.jpg / 12.08.2015)
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
17 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Particle generation for different Wood-Based panels Flake generation for particleboard – PB Waste wood processing – residual wood treatment
(ĺ Slide 19) (ĺ Slide 47)
Strand generation for oriented strand board - OSB
(ĺ Slide 50)
Fibre generation for medium density fibreboard - MDF
(ĺ Slide 54)
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
18 2015Ͳ08Ͳ05
Wood-Based Panels Flake generation
Particle generation
crusher
Flow chart example for raw material processing to generate flakes for particle board production
Impact hammer mill
Stepwise processing Different raw materials Logs (long, short) Slabs, offcuts, chips from Waste wood
\ sawmill
Screening
Maier 03/2005
Overs / rejects breakdown Fines / dust ĺ heat generation Impurities / contaminants Intermediate storage Adapted conveying/feeding systems Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
19 2015Ͳ08Ͳ05
Wood-Based Panels
Flake generation Exemplary flow chart for raw material processing to generate flakes for particleboard production Prof.Dr.JoergB.Ressel Maier 03/2005 www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
Wood-Based Panels
Particle generation
Crusher / Shredder / Pre-braker Slowly rotating crushing rotor, equipped with particular teeth to disintegrate wood residues, waste wood (Æ pallets, packaging materials, etc.), generating coarse, prebroken raw material, requiring less volume and easier handling and transport. After removal of contaminats (metals, plastics …) the precrushed material is further processed, e.g. in a beater mill.
http://www.holzmatic.com/wpcontent/uploads/2008/12/shredd er.jpg
Large feeding hopper for bulky materials Hydraulic drive protection from overload Discharge sizing grid for pre-crushed material Horizontal grinder
(http://media.westsalem.com/machines/titan-grinder-f1-img1.jpg / 12/08/2015)
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
Maier 08/2015
21 2015Ͳ08Ͳ05
Wood-Based Panels Grinder – vertical / horizontal feed
Particle generation (WSM, West Salem Machinery, OR)
Horizontal feed grinder
Vertical feed grinder
(http://media.westsalem.com/landing/mulch-grinders-shredders-screens.v3.jpg / 12/08/2015)
(http://westsalem.com/wpcontent/uploads/2014/05/titan-grinder-ill.jpg / 12/08/2015)
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
(http://media.westsalem.com/machin es/vertical-grinder-f1-img1.jpg / 12/08/2015)
22 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Impact crusher – Impact shredder
2 or 4-rotor shredder for windscreens, wood, plastics ... http://www.prall-tec.de/cms/upload/bildergalerie/PTG4.bmp / 26.08.2011
http://www.prall-tec.de/cms/upload/bilder/Schredder_zhne.jpg / 26.08.2011
Flake generation
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
23 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Drum chipper
Knife
… used to produce high quality chips from long and short logs, slabs, edgings, thinnings, veneer waste or board trims. Chips are easy to handle, storage is without difficulties and chips allow precise metering into fiberizers and flakers.
Wedge clamping Infeed rollers
A belt or vibratory conveyor delivers the material to the chipper. Draw-in rollers with coarse gripping serration assure certain and continuous feeding. The fed material is chopped inside the case by means of a very robust rotor into quality chips and dis-charged via a heavy breaker screen.
High throughput capacity Applicable for very different feed materials High chip quality Robust, easy maintenance, trouble-free continuous operation Low operating costs Fully hydraulic opening of the housing cover, stator knife carrier, knife clamping, lifting and damping of the swing Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
Screen
Stator knife Pallmann 2015
Pallmann drum chipper - complete system (2013)
Discharge example
24 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Drum chipper Rotor brake and turning device Screen Electro-hydraulic quick-change attachment, heavy duty screen basket for accommodation of the screen plates (wear resistant Hardox steel)
Feed rollers special teeth (surface hardened; high wear resistance. Hydraulic / pneumatic cylinders to regulate the pressure of the upper feed rollers and to open the upper feed rollers for maintenance and easy cleaning Chain drive of the feed rollers
Counter knife / anvil (stator knife) Electro-hydraulic assisted changing of counter knife / anvil http://www.fordaq.com/www/news/2007/Bruks_Kloeckner_Trommelhacker.jpg / 25.08.2011
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
25 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Drum chipper
Vecoplan 2011
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
Flake generation 26 2015Ͳ08Ͳ05
Wood-Based Panels
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
27 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Disk chipper …
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
28 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Disk chipper Used for chipping logs – high quality chips (Æ fiberboard, pulp) Disc chipper consists in a heavy rotating disc (Diameter 1… 3 m) with 4 or more knives. Particle thickness is determined by the angle between in-feed spout and chipping disc
Conventional horizontally fed disk chipper
HHQTM disk chipper
(Andritz 2010)
(Andritz 2010; Bruks 2011)
Disk chipper with chute (Bruks 2011)
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
29 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Disk chipper …
United States Patent 6976516 http://www.freepatentsonline.com/6848486-0-large.jpg / 8/25/2011
United States Patent 6976516 http://www.freepatentsonline.com/6976516-0large.jpg / 8/25/2011
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
30 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Disk chipper Gravity feed chipper …
Metso Paper, Inc. 2010
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
31 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Disk chipper Horizontal feed chipper …
Metso Paper, Inc. 2010
MDF fiber generation Metso Paper, Inc. 2010
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
Flake generation
32 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Impact hammer shredder … converting pre-crushed waste wood particles into raw material for reutilization in panel production or energy generation. Also contaminated materials can be fed into the shredder. Foreign matter, travelling in the feed stock, is separated and automatically discharged. Material is vertically feed from above into the shredder. Heavy rotating hammers hit in an upward action against the feed material and throw it against the inside of the housing top above the rotor where it is pre-broken by impact. The wood pieces are split along the grain, metal contaminants enclosed into the wood are set free in the special feed chute because of their different ballistic curve. The final preparation is effected by stationary breaker and comb bars. The openings of the heavy grid defines the (http://www.pallmann.eu/language/upload/bilderleiste/PHP S3.JPG / 13.08.2015) finished product size. High throughput capacity at low specific energy consumption Impact Hammer Mill PHPS (Pallmann 2015) Separation and removal of foreign matter Insensitive against contaminants and feed fluctuations Flake generation Easy maintenance and access to the rotor Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
33 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Impact hammer mill … particularly used for processing waste wood, e.g., pallets, crates, boxes, scrap wood, wood residues, bushes, branches, industrial waste wood. The process outcome is valuable raw material for the panel industry or for energy generation. A vibro-feeder or an apron conveyor hauls the material towards the machine mouth. Bulky feed material is hydraulically continuously guided towards the rotor, equipped with free-swinging tools, i.e. hammers, steel strips, where it is shredded stepwise by iterated impacts. Material discharge goes downwards through a heavy screen-cage, determining the particle size.
Very high throughput capacity Insensitive against foreign matter Homogeneous final product Vibration free operation Hammers easy to change Low operating cost Low maintenance
Impact Hammer Mill PHPH Grizzly (Pallmann 2015)
Pallmann 2004
Flake generation
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
(http://www.pallmann.eu/language/uploa d/bilderleiste/agrizzly.jpg / 13.08.2015)
http://www.pallmann.eu/language/upload /bilderleiste/Grizzly1.jpg / 13.08.2015)
34 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Knife ring flaker … production of high quality flat flakes from chips, veneer residues, purchased flakes and coarse material of any kind, i.e., also low priced wood assortments can be processed with the knife ring flaker.
Chips
A quick rotating impeller leads the chips to the knives of the counter-rotating knife ring. This principle of counter-rotation from the impeller and the knife ring guarantees a troubleand obstruction-free operation of the machine even with very wet material, a uniform wear of exchangeable knives and counter knives and therewith an excellent flake quality.
Excellent flake quality High throughput rates Quick, economic knife change Economical prize for the performance No clogging at high moisture content Efficient wear protection Maier / Dieffenbacher MRZ (Maier 2011 – 6:06 min)
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
Pallmann 2011
Flakes 35 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Knife ring flaker
Maier 2011
Vibro-feeder Metal separator Heavy particle separator Contaminant separator Controlled air-flow
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
36 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Knife ring flaker Cutting process
Pallmann 2011
(1) (2) (3) (4)
Wear plate Beater plate Wear shoe Knife
(5) (6) (7) (8)
Wear segment Impeller Knife carrier ring Knife carrier
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
Additional information Globus Knife Ring Flaker for particleboard production https://www.youtube.com/watch?v=tEBaPiLrz5w [10:17 m] / 8/14/2015
37 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Knife ring flaker Ring assembly
50 knife konfiguration increases production capacity
Holder assembly
Adjustable knife settings for fine mircrometer knife adjustments that can be made in the ring assembly
Precise fit for conventional knife ring flakers
4-bolt ring attachment allows for quick and easy base assembly removal
3-bolt spring clamping for quick and easy knife release and clamping
Dovetail locking assembly increases strength of system, decreasing the chance of parts releasing during operation
(http://www.keyknife.com/features/images/details/ringslicer_left2.jpg / 28.08.2011)
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
38 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Knife ring flaker Flaker components: vibrating feeder, metal separator (removal of ferrous contaminants), wind selector ( removal of heavy pollutants) and the flaker itself. High capacities Æ KRFs arranged in series. High performance and excellent flake quality requires quick knife ring exchange facilities and particular sharpening and setting equipment
Chips, sawdust Magnetic drum
Vibrating feeder Ferrous contaminants
Wind selector
Knife ring flaker
Heavy Contaminants
Flakes Pal 2005
Drum flaker Pallmann 2011
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
Flake generation 39 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Drum flaker … designed for high production capacities of flat flakes from round wood cut to length ( 2 m). Feed in logs are pushed against the rotating drum by suitable clamping devices. Flake length is determined by a particular knife design (Æ double comb knife); the flakes are crushed to width parallel to grain in the knife pockets.
Double comb knife Clamping strip
Knife fixing plate
Two types of constructions are in use: Drum flaker with stationary rotating drum; continuous flaking of cut to length logs. Wear plate
Drum flaker with rotating drum moving forth and back; discontinuous flaking of random length round wood
Knife Knife fixing plate Clamping strip Drum body
Counter knife
Bridges Flake pockets
Deppe, Ernst 2000; Figs. 3.1-22, 26, 29, 30
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
40 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Drum flaker – Processing steps 1. Feeding the raw material (logs, slabs …) into the processing area 2. Vertical and horizontal adjustment of the raw material by automatic clamping 3. Drawing or scoring cut parallel to grain
Knife types Æ … determine flake length 1. Scarifying knife
2. Comb knife
3. Slitting knife
4. Full knife
c
d e
Hombak 2011
4. Cutterblock and clamping system move back to start position Æ discontinuous process
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
f
41 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Drum flaker
Cross conveyor
Longitudinal conveyor Hombak 2011
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
Flake generation
Particle generation
Hammer mill – Beating Flaker … used for production of core layer and surface layer material for particleboard from waste wood chips, core waste wood particles and annual plants, dry or wet.
Maier MSZ 2015
Wood-Based Panels
The material is feed in vertically from above. A gravity separator separates heavy contaminants from the infeed material. Flat steel beaters (steel strips) rotating with high speed split the feed material mostly parallel to the grain. The openings of the installed screens determines the particle size. Stationary refining elements integrated into the mill assist the size reduction. Particle discharge can be effected either pneumatically or mechanically with an additional secondary suction. High throughput capacity Uniform material preparation at low specific energy consumption High versatility and easy adaptation to various feed materials Maximum utilization of all wear parts Dual operation direction increases economic efficiency Robust and easy to maintain High availability Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
Pallmann PHMS 2011
43 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Prallfiner – Impact mill – Sieve ring mill
Maier MPM 2015
… are used for generating fine particles. Wood particles are thrown against a grinding path by rotating impeller blades and split up mainly along the fibre length. Subsequently particles have to pass a stationary or counter-rotating screen ring; grinding path patterns, screen perforations and shape determine the final particle size of these versatile disintegrating machines.
Sieve Ring Mill MPS
Impact Mill MPM
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
Prallfiner MPF
Maier MPF 2015
44 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Prallfiner 1Vibrationconveyor 2Metalseparator(Magnet) 3Infeed(vibro chute) 4Rotor 5Grindingtrack 6Distributiondisc 7Suctionpipe 8ByͲpass
[4] [5]
[5]
[5]
Flake generation
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
Maier MPF 2015
45 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Waste wood processing – residual wood Two stage recycling plant – dry process
(1) (2) (3) (4) (5) (6) (7) (8) (9)
Crushing – pre-braking Separation of ferrous material Sorting Second disintegrating stage Separation of ferrous material Screening Separation of heavy contaminants Sifting of light particles Separation of non-ferrous material
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
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Wood-Based Panels
Particle generation
Waste wood processing – residual wood Two stage recycling plant – dry process
1. Stage waste wood recycling crushing - cleaning - screening
Urban waste wood (PAL 2003 – 4:30 min)
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
(1) (2) (3) (4) (5) (6) (7) (8) (9)
Crushing – pre-braking Separation of ferrous material Sorting Second disintegrating stage Separation of ferrous material Screening Separation of heavy contaminants Sifting of light particles Separation of non-ferrous material
2. Stage waste wood recycling beating - cleaning - screening
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Wood-Based Panels
Particle generation
Waste wood processing – residual wood
Bunkers for separated and cleaned residual wood fractions
Containers for re-moved materials (plastics, non-ferrous metals, …)
Deppe, Ernst 2000, Fig. 2-1.37
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.
Infeed belt Belt conveyor Drum screen Transport belt Flat screen Transport belt 0/24 Transport belt 0/24 Metal separator Transport belt 0724 Belt for fuel material Separation belt 24/80
12. 13. 14. 15. 16. 17. 18. 19. 20. 21.
Separation belt 80/150 Separation belt 150L Collecting funnels Transport belt 24/80 Transport belt 150L Transport belt 80/150 Wind screen 80/150 Wind screen 24/80 Control panel Transport belt
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Wood-Based Panels
Particle generation
Decomposition of UF-bonded and laminated particleboard Semy-dry two stage chemo-thermo-mechanical batch process, annual capacity of one decomposition unit up to 20.000 t/a of particles in three shifts
Vacuum pump
Recycled furniture, production residues, rejects
Heat Crusher infeed
Pre-crusher (breaking up)
t = 1…10 min
Pre-impregnation (possibly after vacuum treatment)
Impregnation liquid (caustic soda solution, urea, water)
Slowly rotating pre-braker
Discharge condensate and surplus Impregnation liquid
Heat-treatment t § 20 min T = 110 ºC (chemical-hydrolytic process) Water, urea and additives
Screening
Wood particles
Coating and edge banding materials
Reaction bin (insulated) including quick closing lid and discharge device
Particleboard
Refiner MDF
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
Moving floor Stoker discharge Bin for preparation and storage of the impregnation liquid
Particles (to dryer and screen)
Coarse wood particles, metal parts, plastic and coating materials
Drum screen
Pilot plant for processing urea bonded particleboard – used furniture and production residues (WKI 1996) Particle recovery process from urea bonded particleboard (according to Michanickl and Boehme, WKI 1996) 49 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Strand generation for OSB – Long log (knife) ring flaker … particular knife ring flaker for producing precise strands with specific length, width and thickness from either fixed length logs or random length logs. The long log ring flaker is mostly used for flake generation for Oriented Strand Board. Pallmann 2011
The logs are batchwise fed into the flaking chamber with an integrated water injection system. Particular vertical swords hold down the logs during the cutting stroke. A closing gate hydraulically clamps the log bundle at the flaking chamber and closes the flaking chamber during the final cutting stroke. The wood is cut parallel to grain; this cutting action results in rectangular flakes with smooth surfaces and a minimum of fines. OSB strand generation
Pallmann 2011
(Siempelkamp 2013 – 1:45 min)
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
50 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Strand generation for OSB – Long log (knife) ring flaker
Pallmann 2008
Pallmann 2008
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
51 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Strand generation for OSB – Disc strander … cuts tree length or batch fed logs into strands for OSB production. The clamping system secures the logs in place while the strander, which is carriage mounted, extends into the cutting chamber. Discmounted knives strand the wood within the cutting chamber and the carriage returns automatically to repeat the sequence. The knives on the strander extend to the outer edge of the precision ground disc, allowing the disc to advance through the batch of logs during stranding while maintaining consistent strand thickness..
Disc Strander
Kadant Carmanah 2015
(Kadant Carmanah 2015 – 0:20 min)
Disc Strander for long logs Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
… for short logs – Block Strander 52 2015Ͳ08Ͳ05
Wood-Based Panels
Particle generation
Strand generation for OSB – Knife ring flaker Two-step process for strand generation developed by Maier (2002) Raw Green wood (logs, thinnings, tree tops), sawmill residues materials (slabs, offcuts) and residual wood Step 1
Step 2
Drum chipper HRL/OSB ĺ chipping raw material into OSB chips; chip dimensions have to meet the requirements for desired strand length.
1
Knife ring flaker MSF ĺ converting OSB chips into strands.
Quantity of surface and core layer strands and the content of fine material obtained hardly differ from the respective quantities obtained from conventional strand production. The two-step process supports inexpensive plant concepts with an increased flake capacity of existing plants, to install medium-size plants at lower investment expenditure, or to produce novel board types from recycling wood. Fines are usable for particle board production or as fuel.
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
2
Drum chipper HRL/ OSB (Maier 2011)
Knife ring flaker MSF (Maier 2011)
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Wood-Based Panels
Fibre generation
Fibre generation for MDF … based on a two step process. Initially cleaned wood (washing, debarking of logs) is converted into chips or are purchased, e.g., as sawmill by-product. In the second wet process step the chips are converted into fibres by means of a refiner; also sawdust can be processed in the refiner (requires particular grinding plates).
Chipping and storage
Chip preparation and fibre production Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
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Wood-Based Panels
Fibre generation
Chip generation Chips purchased either as raw material from sawmills (Æ particular quality requirements) or directly made from green wood (logs, sawmill residues) by means of a drum chipper or a disc chipper (the latter is the most common chipper in pulp mills). Cleanliness of chips, uniformity of chip size and clear cut surfaces are very important for even conversion into fibres in the following pressurized defibration process. Disc chipper types (Andritz 2002)
Chip storage • Open air storage or storage in suitable metal/concrete bins/silos • Material losses due to thermal degradation and/or fungi attack
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
55 2015Ͳ08Ͳ05
Wood-Based Panels
Fibre generation
Defibration process Steam flow Material flow
Chip bin (preheating)
8…19 bar abs. Digester
Refiner (grinding chamber) Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
H. Roll (2008)
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Wood-Based Panels
Fibre generation
Defibration process Energy consumption – reference values Steam – Refining Process Nominalvalues 500– 850kg/tfibre Practical values 250– 450kg/tfibre
ChipBin (target chips at outfeed 60°C)
35%… љwith discharge limitations Æ steam digester, Æ energy consumption fibre dryer ј јif chips are frozen (inpractice +50…60%; designvalue approx. +100%)
Digester
60%
Grinding Chamber
4%(depend.onȴpDig.ͲRef.,Blow valve opening
Others
1%(max.200…250kg/h)
Mechanical Energy (Elektricity)– Refining Proces Softwood (Spruce)
80– 170kWh/tfiber o.d.
Hardwood (Beech)
90– 150kWh/tfiber o.d.
Sawdust 100%
250– 400kWh/tfiber o.d.
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
H. Roll (2008)
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Wood-Based Panels
Fibre generation
Defibration Process steps 1. Screening of chips (uniform chip size and shape, removal of over-sized chips and contaminants) 2. Chip conditioning by means of a moistening screw 3. Double mixing screw to feed chips into the pre-steaming bin. Pre-steaming reduces the temperature difference to the affiliated cook-ing process. The forming condensate in the pre-steaming bin can easily squeezed out in the plug screw feeder and chips have to be only heated up in the digester from pre-steaming to cooking tem-perature. Condensate reduction in the chips also significantly saves energy in the fibre drying process. 4. To prevent from steam blow-out from the digester (temperature and pressure drop) a blow back valve is located opposite the plug screw feeder to close the digester infeed opening if necessary. 5. The digester is used to heat up and cook the chips. Retention time – an important parameter to fibre quality - is determined by flow rate and digester level indicated by a radioactive level mea-suring device. Digester discharge is accomplished by particular discharge unit underneath the digester on customers indications on wood species, bulk density and chip moisture content. Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
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Wood-Based Panels
Fibre generation
Defibration process steps (cont.) Before chips enter the refiner they have to pass a ribbon feeder, which operates at constant speed and feeds the material continuously into the refiner. At the same time it allows steam, generated in the refiner to flow back into the digester trough the steam equalization line. 6. Typically the refiner is designed as single disc pressurized refiner with a rotating and a sta-tionary plate holder. The rotor is adjustable in horizontal direction to the stator which is mounted stationary onto the door. While at lower throughputs the plate gap will be electromechanically adjusted the large refiners use a most precise and reliable hydraulic plate gap adjustment. By adjusting the rotor against the stator the power consumption of the refiner main drive motor can be increased or decreased, which allows adjusting the specific energy to the refining process, considering different raw materials and the required end products. To increase the refiner speed, e.g., for processing sawdust, an additional high speed gear is built in. (Andritz 2005)
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
59 2015Ͳ08Ͳ05
Wood-Based Panels
Fibre generation
Chip washing process Chips
Chip washing is essential for producing board with low mineral content.
Increasing use of purchased chips, e.g. from sawmills, results in an everincreasing need for chip washing. Existing impurities, as metal parts, stones and sand, must be removed Closed water before the chips enter the process. circuit
(Æ CleanMax System) Metso 2010
Waste water processing
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
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Wood-Based Panels
Fibre generation Chip treatment and refining
Blow back valve
Metso 2010 Metso 2010
FeedMax Æ screw feeder upgrade provides uniform feeding, optimized dewatering and reduced energy consumption
Metso 2010
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
Metso 2010
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Wood-Based Panels Refiner unit
Fibre generation Top view
Side view
Metso 2011
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
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Wood-Based Panels
Fibre generation
Refiner unit
Pallmann 2015 Æ http://www.pfalz-express.de/wp-content/uploads/2013/02/Pallmann-Refiner.jpg / 17/08/2015
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
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Wood-Based Panels
Fibre generation
Refiner unit
Single-Disc refiner
EVO-series Defibrator™
Metso 2011
Energy saving EVO helical discharge.
Andritz 2011
Traditional radial discharge. Metso 2006
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
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Wood-Based Panels
Fibre generation
VALMET Evolution Defibrator Series (former METSO - EVO-series Defibrator™) Development objectives Æ reduced energy consumption and better fibre quality by improved furnish flow into and through the refiner by particular high-speed screw feeder, efficient dewatering ĺ reduced mc in pre-heater, less steam demand, less mc at dryer inlet new infeed geometry in coarse breaker bar section of the segment area and improved centre plate design, low-energy unidirectional refiner segments,
Metso panelboard 2006
Metso 2010
helical discharge – instead former radial discharge - combined with blow valve. Specific energy saving approx. 25 … 50 kWh/ton softwood fibres, i.e., approx. 10 % for all fibre qualities compared with the M54 Defibrator. Additional reduction of specific steam consumption by 25…45 % Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
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Wood-Based Panels
Fibre generation
Refiner and refiner plates
Refiner plate details (Durametal Corp. / Andritz 2004)
Refiner … main machine for chip conversion into fibres. Softened chips are feed in the central area of the pressurized defibration zone between particularly designed refiner plates mounted on the stator and rotor respectively. Refiner plates consist of replaceable segments with a special bar and groove pattern. Pattern design (mostly depending on wood species) and adjustable distance between the two discs determine for refiner energy consumption and fibre quality. Additional refiner characteristics are: Mechanical sealing Hydrodynamic axial bearing Radial roller bearing Electromechanical disc adjustment Disc diameter: 44”, 50”, 56”, 64”, 70”, 74” Throughput: 10…65 to.d./h Power supply main drive: § 5…20 MW
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
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Wood-Based Panels
Fibre generation
Refiner plates … design reduced energy consumption + increases fibre quality 58°
Inconsistant cutting angle
30°
Constant cutting angle of 30°
(http://www.andritz.com/service-pprefinerplatesandfillings-mdf-spiral-en.pdf / 17.08.2015)
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
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Wood-Based Panels
Fibre generation
Refiner – additional equipment Blow valve - directly attached to the discharge opening of the refiner and actuated by means of a pneumatic actuator and electro-pneumatic positioner as well as a manual remote station. The purpose is to gradually adjust the opening to the blow line to allow the actual fibre steam mixture being safely discharged from the refiner.
Andritz 2004
Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
Three way fibre diverter valve is used when different raw materials (chips, sawdust …) are processed in the refiner to meet the required velocities for the glue injection by using different piping diameters. The fibre diverter valve is a rotating diverter driven by two pneumatic cylinders attached to a base frame.
Start-up cyclone guarantees a safely start-up of the system. After checking the fibre quality at the starting cyclone and rechecking if all characteristic values have levelled off and remain constant the valve is switched to production.
Andritz 2004
Andritz 2004
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Wood-Based Panels
Overview / Intro Prof.Dr.JoergB.Ressel www.biologie.uniͲhamburg.de/zentrumͲholzwirtschaft.html
69 2015Ͳ08Ͳ05