Preliminary Internal document – not for external distribution!
© 2018 C.C. JEN
SEN A/S ǀ Ver. 001 ǀ May 2018
Application & Selection Catalogue
Pulp & Paper
Oil Maintenance
2
Table of Contents Paper & Pulp – The Application ...............................................................................................................................................................1
Key Decisions Figures for CJCTM filters: ................................................................................................................................................1
Pulp & Paper Questions .......................................................................................................................................................................1
Vital Machines .....................................................................................................................................................................................1
Paper & Pulp – CJCTM Filter Applications .................................................................................................................................................2
Principle Drawing Harvesting ..............................................................................................................................................................2
Principle Drawing Pulp & Paper Mill ....................................................................................................................................................2
Harvesting ...............................................................................................................................................................................................3
Log Handling Equipment .........................................................................................................................................................................4
Pulp Mill ...................................................................................................................................................................................................5
Paper Mill – Wire .....................................................................................................................................................................................6
Paper Mill – Press, Dryer, and Calenders .................................................................................................................................................7
Finishing ..................................................................................................................................................................................................8
Water Treatment .....................................................................................................................................................................................9
Filter Selection .......................................................................................................................................................................................10
Filter Selection: HDU – Hydraulic...........................................................................................................................................................11
Filter Selection: HDU – Gear ..................................................................................................................................................................12
Filter Selection: PTU – Hydraulic ...........................................................................................................................................................13
Filter Selection: PTU – Hydraulic/Lube ..................................................................................................................................................14
Desorber Selection ................................................................................................................................................................................15
Paper & Pulp References .......................................................................................................................................................................16
Bearings and Bearings Houses from PM 6 & 7, Norway ....................................................................................................................16
Paper Mill Lubricating System, Norway .............................................................................................................................................17
Paper Mill Lubrication System, Canada .............................................................................................................................................18
Hydraulic Power Pack, Debutter, Sawmill, Ireland ............................................................................................................................19
Super Clalender, Hydraulic Oil, Sweden ............................................................................................................................................20
Appendix #1 : The Application and Questions .......................................................................................................................................21
Appendix #2 : Wood and Chips..............................................................................................................................................................22
Appendix #3 : Pulp .................................................................................................................................................................................23
Appendix #4 : The Paper Machine .........................................................................................................................................................25
Appendix #5 : Paper Finishing and handling ..........................................................................................................................................29
Appendix #6 : Water treatment ............................................................................................................................................................31
1
Paper & Pulp – The Application
The paper making process is a multistage process of harvesting, wood chip and pulp manufacturing, and paper making that are exposed to a variety of conditions. There are hundreds of oil systems, which most can benefit from getting a CJCTM filter fitted.
The two latter stages consist of a Pulp Mill and Paper Mill (Paper Making Machine) are the two most ideal candidates for CJCTM filters. The Mills utilize mass production and all downtime is very expensive. It is therefore recommended to utilize CJCTM filters to drastically reduce all oil‐related downtime. It is estimated that 80% of all problems and water in oil systems are caused by contamination of particles and fitting a CJCTM filter can remove about 40 % of all downtime. (Rough estimates).
Furthermore, pulp mills and paper mills work with heat, steam and water, which increase the possibility of water ingression through condensation or leakage. Water is a huge problem for any oil system and can drastically reduce the longevity of oil and oil system components. The heat can also generate problems with vanish and sludge.
The harvesting stage functions differently and consists of heavy mobile machinery that are exposed to the environment such as temperature changes, dust and water, which easily can find their way into the system. Although these machines do not have high operating hours they are still prone to wear. When in use, it is vital that the machines operate at the highest efficiency and contamination of the hydraulic system can slow productivity with up to 20 % before it is noticed, which corelates to about 1 day every week of lost efficiency. Clean oil will increase reliability, shorten maintenance intervals, decrease maintenance costs, and remove jerky, erratic operation.
Important** Pulp mills and paper mills can have their own power plants but in this CJCTM application catalogue the focus is only on pulp & paper manufacturing. For power plant information, please see the CJCTM application catalogue for power generation.
Key Decisions Figures for CJCTM filters:
To dimension CJC Oil Filters there are five important factors to investigate:
Environment Risk of water Ingression Varnish issues
Pulp & Paper Questions
Which oil system do you spend the most time on?
How do you do oil maintenance today?
How many unscheduled stops did you have last year and what where the costs involved?
How often do you change critical components and have you calculated the total cost of a component change?
What does it mean to you to increase reliability and up‐time?
Vital Machines
Paper Machine
Refiner/Grinder
Digester
Super Calender See Appendix #1 for more information.
2
Gear, Bearing & Hydraulic Filtration
Gear & Bearing Filtration
Debarker
Gear & Bearing Filtration
Gear & Hydraulic Filtration
Gear & Bearing Filtration
Central Lube System
Gear, Bearing & Hydraulic Filtration
Operation: Δ 2000 hours per year
Selling points: Reduce Maintenance cost and Increase Reliability
Operation: 24/7
Selling points: Reduce downtime and maintenance cost
Paper & Pulp – CJCTM Filter Applications
Principle Drawing Harvesting
Principle Drawing Pulp & Paper Mill
Harvester Forwarder
Motor Lube & Hydraulic Filtration
3
Harvesting
Harvesting is a general term used to describe the felling/cutting of trees and preparing them for transport to the mills. It includes both thinning and clear‐cutting operations. The harvesting process includes a variety of trucks, such as the Harvester and the Forwarder. They all have hydraulic systems, may include gears and engines, which can benefit from CJC filtration. All vehicles utilize biodegradable oils due to legislations.
The Problem
Harvesting equipment is exposed to the outdoor environment on daily basis when in operation. This means they are exposed to temperature changes, dust and water that easily can find its way into oil systems. Furthermore, this equipment is left overnight and the work locations.
Environmental conditions
Dust, water, temperature
The Consequences
Lost productivity (slow hydraulics)
Loss of reliability
Increased maintenance costs
The Solution
Due to the equipment being left in remote areas an on‐board solution is required. It is important to keep hydraulic oil system cleanliness at ISO 16/14/11 and moisture at max 300 ppm. This can be achieved with a hydraulic filter, either HDU HDU 15/12, HDU 15/25, or HDU 27/27. Gear and engine oil can also benefit from a CJC filter. Often, a HDU 15/25 is installed directly on the mobile equipment. For a more detailed overview of filters for mobile machines, see the Mining catalogue.
The vital parameters influencing the filter selection are oil system volume, water ingression, oil temperature, oil viscosity, and filter size. Filter selection can be found on 11 and onwards.
4
Log Handling Equipment
In the process of creating wood chips needed for pulp manufacturing different log handling equipment is utilized. This includes a debarker, a chipper, and a grinder/refiner. Furthermore, a large conveyor belt may be used and each stretch may have several gearboxes, and a large hydraulic lift for trucks may be utilized, if the wood chips come from a more remote location, to unload the cargo.
The Problem
Most likely, the mentioned log handling equipment will be installed outdoor greatly increasing the contamination of the oil systems via temperature changes, dust and water. Aspects such as poor breathers, worn wiper seals and so forth greatly increase contamination.
Contamination from particles
Dust, especially from wood chips
Water condensation
The Consequences
Dirty and wet oil reduces equipment efficiency and result in short service life for the oil. Hard particles and varnish will cause servo and proportional valve to stick, resulting in unscheduled stopping of equipment. Contamination often cause up to 20 % loss of efficiency in the hydraulic systems where the oil cleanliness is often above ISO 22/20/16 and moisture above 1000 ppm. Each of these machines have gear and hydraulic oil systems that can benefit from CJC filtration.
Short lifetime of oil and components
Unscheduled downtime
Loss of efficiency (about 20%)
*Debarker often utilizes grease. Only if an oil system is utilized, then CJCTM filter can be fitted.
The Solution
By doing oil maintenance on the above machinery there will be savings within maintenance due to a prolonged lifetime of oil and components, and increase to productivity and a reduction of downtime. The installation of a HDU system will both remove the particles, varnish and water contents from the oil. Check filter selection guide. The selection parameters depend on the oil system volume, oil viscosity and ambient temperature (oC).
The refiner gear utilizes lube oil that can benefit from CJC filtration as it gets wet and dirty. This can be solved by a HDU with 20 – 50 % circulation ratio or PTU2 27/27 mobile cart depending on water ingression.
The vital parameters influencing the filter selection are dirt ingression, oil system volume, oil temperature, and oil viscosity. Filter selection can be found on 11 and onwards.
See Appendix #2 for more information.
5
Pulp Mill
A pulp mill consists of a long line of different machinery that works with converting wood chips or waste paper into different types of pulp. The machinery that may benefit from CJC filtration are; the digester, pulp thickener, refiner, pulper, deinking machine and slab press. There may also be other machinery, unique to the pulp mill, with oil systems that benefit from filtration.
The Problem
The pulp mill is located in an indoor but wet environment. This causes a larger water ingression rate and contamination of the oil systems within the pulp mill. Furthermore, particles from wear and the manufacturing of pulp can also enter the oil systems. Some machines, such as the slab press may operate with high temperature oil causing varnish to form.
Water contamination
Varnish contamination
Particle contamination
Pulp, wear, dust
The Consequences
High concentrations of water within oil greatly reduce the lifespan of the oil in the system and increase wear on components.
Shorter lifespan on oil and components
Increased downtime
Frequent change of critical components and oil
The Solution
The solution varies a bit from machine to machine but in general the solution would have to solve water ingression and dirt contamination. Most have a gearbox that can benefit from CJC filtration. The digester has at least two gearboxes, agitator and worm gear type. Other machinery may have similar gearboxes.
Agitator Gearbox – Continuous CJC offline filtration – HDU 15/25, BG 15/25, 45 l/h flow
Worm type Gearbox – Part time CJC offline filtration – HDU 27/27, B 27/27, 90 l/h flow, mobile cart
The slab press and other machines with constant high temperature oil would benefit greatly from the VRU 27/108 for a 3,000 – 5,000 liter hydraulic oil system.
The vital parameters influencing the filter selection or oil system volume, water ingression, oil temperature, and oil viscosity. Filter selection can be found on 11 and onwards.
Digester
See Appendix #3 for more information.
6
Paper Mill – Wire
The paper mill consist of a paper making machine, which is the most expensive, complex and critical machine in the paper mill. The largest of such setups, the Metso PM12 from Sweden, runs at 2,000 m/min and produces 420,000 tons of paper each year. The wet section reduces the water content of the paper from around 95 – 90 % to 50 %. This is done using wire system, where water is drained through the wire. Uptime and continuous paper manufacturing is a must and paper mills can therefore benefit from CJC filtration greatly. This page only considers the initial wire section of the paper machine, although the main lube system may be utilized for other components as well.
The Problem
Usually the paper machine has a main central lube system that consists of 5,000 – 30,000 l oil, typically ISO VG 220 – 460. The hydraulic oil is mostly ISO VG 46 and consists of around 1,000 – 3,000 l. The pulp consists of a lot of water and there is a large water ingression in both lube, gear and hydraulic oil on the wet end of the paper machine. The water in the main lube systems creates emulsions with water.
Large water contamination
Possible varnish issues
Particle contamination
Wear from machines, dust
The Consequences
The very high concentrations of water within the lube, gear and hydraulic oil greatly reduces the lifespan of the oil in the system and increase wear on components.
Frequent change of oil and critical components
Increased downtime
Shorter lifespan on oil and components
The Solution
Main lube system
As the ISO VG 220 – 460 oil in the main lube system creates emulsions with the water a PTU cannot be utilized. A HDU with a BLA insert and a Desorber according to the oil system volume is recommended with a 10 – 15 % circulation ratio for the HDU
Hydraulics system
Most likely a PTU can be utilized on the hydraulic system otherwise a similar system as mentioned above. PTU 27/108 with a 15 % circulation ratio. If the system contains large varnish issues VRU may be needed. Always make a demulsibility test if there is water in the system, to verify that the PTU will work.
The vital parameters influencing the filter selection or oil system volume, water ingression, oil temperature, and oil viscosity. Filter selection can be found on 11 and onwards.
See Appendix #4 for more information.
7
Paper Mill – Press, Dryer, and Calenders
The press‐, dryer section, and calender stack are the following steps after wire section. The paper enters with around 50 % moisture and is reduced to 10 %. Often the same main lube system, as mentioned on the previous page, is utilized for each section. As can be seen in the provided picture, the paper mill consists of many rollers that utilize expensive spherical roller bearings costing around 6,000 – 8,000 euros each (two per roller). After the paper machine, the paper is put through the super calender that consists of many rollers with a large hydraulic system of about 10,000 – 20,000 l of oil. Since the super calenders bend under the constant pressure they utilize hydraulic controlled rolls. A typical system can have up to 76 hydraulic pistons.
The Problem
There is a large water ingression on the hydraulic and lube systems causing damage to the components and oil systems. Varnish can also be an issue in these large oil systems. Furthermore, rollers that are put on stock with the expensive bearings still contain water, which will result in corrosion.
Large water contamination
Possible varnish issues
Water contaminated bearings on stock
The Consequences
The large water contamination issues to the oil systems greatly increase wear on components and oil and the bearings put on stock with water increase corrosion and can reduce the lifespan of the bearings with up to 50 %.
Shorter lifespan of critical components (bearings with up to 50 %)
Unscheduled downtime
Loss of hydraulic system efficiency
The Solution
The sections may have their own lube oil and hydraulic oil systems that require a HDU with BLA insert and a desorber for the lube oil and a PTU filter for the hydraulic oil. The hydraulic oil system for the super calender can be solved with a HDU, often HDU 27/108, depending on the oil system volume. A 15% circulation ratio is recommended for the HDU a VRU may be needed if the system has large varnish issues. Rollers/Calenders can be cleaned before being put on stock with the Tonning Trolley.
The critical factors affecting filter selection are oil system volume, oil temperature (varnish issues), oil viscosity, and water ingression. Filter selection can be found on 11 and onwards.
See Appendix #4 for more information.
8
Finishing
When the paper has gone through the super calender it is reeled onto rolls and then coated at the coater depending on the application of the paper and lastly cut into the desired size before packaging. The reeler, slitter, coater and handling system all have oil systems that can benefit from CJC filtration.
The Problem
These machines are all subjected to oil contamination from varnish or particles.
Particle contamination
Dust, wear
Varnish contamination
The Consequences
These problems reduce efficiency and increase maintenance costs along with causing downtime.
Reduce efficiency of hydraulics
Increase maintenance costs
More frequent downtime
The Solution
The oil systems are not as large on these machines and for the hydraulics oil system a HDU B 27/27 with 150 l/h oil flow and for the lube oil system a HDU B 27/81 with heater if temperatures are not at about 55 oC are recommended. The hydraulics system can have a small HDU 15/25 CJC filter with a slightly lower flow and an oil temperature at around 55 oC. Some oil systems may be combined and or larger machines are in place, which would change the required CJC filter.
The critical factors concerning CJC filter selection are oil viscosity, oil temperature and oil system volume. Filter selection can be found on 11 and onwards.
See Appendix #5 for more information.
9
Water Treatment
The pulp and paper mill utilize a lot of water and produces a lot of effluent water. The water needs to be treated so it can be reused or can run off to river/lakes. The water is treated in large pools containing bacteria and is run by an agitator. If the agitator breaks down a loss of bacteria will follow, which will decrease the amount of water that can come through the water treatment facility and influence the manufacturing rate of the pulp or paper mill.
The Problem
The agitator is driven by an electric motor connected to a gear box. It is located outdoor and exposed to dust and water that wear on the oil and gear. The gear can also develop lots of heat under the heavy load, which degrades the oil at a quick rate.
‐ Outdoor installation ‐ Dust and water contamination ‐ Hot oil, increase degradation rate
The Consequence
The gears lifespan is greatly reduced and needs to be changed frequently.
‐ Decreased lifespan ‐ Frequent gear change ‐ Loss of reliability
The Solution
Each agitator has an oil system volume of about 50 – 200 l with ISO VG 150 – 320 gear oil. For each agitator a HDU 15/25, 45 l/h, with BG inserts are recommended as cheap safety.
The critical factors concerning CJC filter selection are oil viscosity, oil temperature and oil system volume. Filter selection can be found on 11 and onwards.
See Appendix #6 for more information.
10
Filter Selection
To select a CJCTM filter solution the following parameters must be known to provide the best fitted solution:
Oil System Volume, L
Oil Viscosity
Ambient and Oil Operation Temperature, oC
Water Ingression
For larger systems, a demulsibility test is recommended.
Environment
Varnish Issues
From this information a suitable insert can be selected and a suitable CJCTM filtration system can be selected.
HDU
PTU
VRU
Desorber
Insert Type
Insert ID (type and size) K‐value (10‐6)
B B 15/12 75
B 15/25 49
B BG
B 27/27 11
BG 15/12 50
BG 15/25 25
BLA(T) BLA 15/25 22
BLA & BLAT 27/27 9
The pressure drop, ∆ , must not exceed 0.3 bar and can be calculated using the following formula
∆∗ 10 ∗ ∗
Q : Flow rate (l/h)
n : number of inserts
v : Viscosity
For larger unique system the application specialist must be contacted.
11
Filter Selection: HDU – Hydraulic
*The filters are multi‐voltage and can be delivered with a different voltage supply.
12
Filter Selection: HDU – Gear
Will be added as soon as technical support has complete creating the require product numbers.
13
Filter Selection: PTU – Hydraulic
Constant water ingression and oil doesn’t create emulsions with water.
Check demulsibility:
Max 20 min, max 4 ml emulsions, eg. 38/38/4 (20 min)
*The filters are multi‐voltage and can be delivered with a different voltage supply.
A different flow rate and or oil viscosity can change the parameters of selection.
14
Filter Selection: PTU – Hydraulic/Lube
Check demulsibility, max 20 minutes 38/38/4.
Lube oil with constant water ingression.
* The filters are multi‐voltage and can be delivered with a different voltage supply.
A different flow rate and or oil viscosity can change the parameters of selection.
For oil types significantly lower than ISO VG 150, like hydraulic oil systems, follow the PTU selection guide to select an appropriate PTU separator solution.
15
Desorber Selection
Oil with emulsions or higher than ISO VG 150.
16
Paper & Pulp References
Bearings and Bearings Houses from PM 6 & 7, Norway
Norske Skog Union, Skien, Norway
The Problem
Oil analysis indicated a very high water concentration that caused corrosion and wear on the bearings deceasing their lifespan with up to 50 %.
The Solution
Protect bearing against corrosion by adding a clean and dry oil film. Maintenance Manager, Torfinn Tonning, working at Noske Skog Paper, helped with the development – hence the Tonning Trolley.
The PTU with two electrical pre‐heater are placed on top of a rather low tank containing 70 liters. All necessary equipment is mounted on the tank with panel for controlling heaters and start/stop of the pump.
The Result
Condensation and water was removed from the bearings and bearing houses and now they have dry oil and a protective membrane on the bearings before storage.
When water is removed from bearings it will reduce corrosion damages in both bearing house and rollers. This will increase bearing life time.
Case # N/A
Paper & Pulp
17
Paper & Pulp References
Paper Mill Lubricating System, Norway
Norske Skogindustrier ASA, Saugbrugsforeningen, Halden, Norway
______________________________________________________
Comments
Maintenance Manager Per‐Erik Halvorsen:
“The results proves that the CJC Desorber we have purchased is an extremely efficient water removing device. We also have experienced that the desorber is very easy to operate and to maintain. After running‐in it requires no adjustments and almost no surveillance. It is remarkable how much water it is able to remove.
CJCTM Desorber D38 GP‐EHIT
The System
Central lubricating system for PM 4 paper machine. The tank contains about 13,000 litres of Mobil DTE BB Oil PM mineral oil. The tank consists of 3 chambers (return, settling and suction). Oil temperature 60oC. A centrifuge used to be installed on the lubricating system, but it could not keep up.
The Problem
A high water content was detected over a long period of time on PM 4 at Norske Skogindustrier ASA. Large water drops were to be found under the top of the tank. The oil was discolored and cloudy, and the water content was as high as 3.1 % (31,000 ppm).
The situation become even more serious, when rust in both bearings and bearing housings was found during a maintenance stoppage. Bearings also seized due to rust formation. Several bearings and bearing housings had to be replaced during the stoppage.
The Solution
For water removal a CJC Desorber type D38 GP‐EH1T with a 1400 l/h circulation pump was installed. The desorber draws the oil from the return chamber and delivers the treated oil back to the suction chamber.
The Result
The desorber has taken out an average amount of 0.5 l of water per hour since it was installed. All visible water drops under the top of the tank have disappeared and the oil have regained its original color and is clear.
ASIN5014‐UK
Paper & Pulp
18
The System
Machine: Paper machine bowser lube system
Oil type: 12,000 liters of Chevron CLARITY 220 ISO VG220
The Problem
Poor oil quality led to a reduction in the bearing life expectancy. Initial ISO code was 22/21/18 (2/5/15 μm). Target cleanliness level was set at 19/16/13. Water ingress was also a problem, though they already had a vacuum dehydrator installed to help dry the oil.
The Solution
A CJCTM Fine Filter HDU 2*27/108 GP‐EPT was selected to bring the oil down to the target cleanliness level. This unit was fitted with a GP‐33‐4 pump at flow of 3,200 liters/hour. We chose a CJCTM Filter Insert BLA 27/27 for its ability to handle excessive water concentration.
The Result
The sample results show a dramatic improve‐ment in the first three months; particle levels dropped to 18/17/14 as the oil quality improved. The subsequent months show a more gradual improvement, highlighting CJC’s ability to actually clean the inside surfaces of the lube oil system (valves, hoses, etc.) by circulating clean oil. The most recent laboratory results indicated an ISO code of 16/14/11, roughly 1/100th of the initial particle count.
Paper & Pulp References
Paper Mill Lubrication System, Canada
CJCTM Fine Filter HDU 2*27/108 GP
ASIN5062‐UK
Paper & Pulp
19
The System
Hydraulic power pack for the debutter system. A debutter (a butt end reducer) shaves off the flare on a log to leave it parallel and therefore easily cut. The hydraulic power unit drives all the movements of this process.
Oil Type: GEM 46 Volume: 600 L
The Problem
Sticking servo valves, that had to be cleaned every week, gave a lot of maintenance work on this power pack. The particle level was high, mainly due to the harsh environment. The system further suffered from a high level of varnish/resin that caused the valves to stick.
The Solution
Due to the contamination level, a CJCTM Fine Filter HDU 27/27 P, using a CJCTM Filter Insert B 27/27 was installed.
The Result
After installation of the CJC™ Fine Filter HDU 27/27, the results were reduced from ISO Code 21/20/17 to ISO Code15/14/9 meaning a reduction on 2 μm count from just under 2,000,000 to 21,000 e.g. a reduction factor of almost under 100 ‐ making cleaning of the servo valve unnecessary.
Paper & Pulp References
Hydraulic Power Pack, Debutter, Sawmill, Ireland
BALCAS Timber Ltd. Largest sawmill plant in Ireland
ASIN5112‐UK
Paper & Pulp
20
The System
Hydraulic system. Top roll for super calender. Oil Volume: 3000 L Oil Type: Synthetic oil Shell Delima SW 320
The Problem
The oil was heavily oxidized due to hot oil in the system, normal temperature in the range 80‐90°C. The valves controlling the bowls were sticking, causing down time, and had to be renovated at regular intervals. The acidity level of the oil (TAN) was 0.62, alarmingly high. In comparison, new oil has a TAN of 0.3.
The Solution
CJCTM Fine Filter HDU 27/54 P. Pump flow 600 L/h. CJCTM Filter Inserts 2 x BLA 27/27.
The Result
The inserts retained very large quantities of oil degradation products from the oil (see photos of the inserts to the right) and the acidity level (TAN) was reduced to 0.51 and stabilized at an acceptable level.
Paper & Pulp References
Super Clalender, Hydraulic Oil, Sweden
ASIN5106‐UK
Paper & Pulp
21
Appendix #1 : The Application and Questions
Although paper making techniques have been refined in the last 20 years, the basic concept is still the same. You take paper pulp and pass it through multiple rolls to squeeze out the liquid and then dry it to produce paper. May sound easy, but a modern paper mill is divided into several sections, and often has its own power plant. There are hundreds of oil systems, which most can benefit from getting a CJC filter fitted.
Pulp is refined and mixed in water with other additives to make a pulp slurry. The head‐box of the paper machine (Fourdrinier machine) distributes the slurry onto a moving continuous screen, water drains from the slurry (by gravity or under vacuum), the wet paper sheet goes through presses and dries, and finally rolls into large rolls. The outcome often weighs several tons.
Questions to ask
S Situation questions
Which equipment is the most important one(s) in the plant?
Which oil system do you spend most time on?
What kind of oil maintenance do you do today?
P Problem questions
Do you have limits on oil sample results (cleanliness, metal in ppm etc.)
Which spare parts/components are most expensive?
How many unscheduled stops did you have last year and what where the cost involved?
What do you do when you find varnish or water in the oil systems?
I Implications/ Consequences
What implications does oil change have on operation or production?
What is the cost of lost production?
How much time does the service people spend on” fire‐fighting tasks”?
Do you guarantee delivery time to your customers which you cannot keep if the productions stop (e.g. day‐to‐day delivery)?
N Need pay‐off Customer benefits
If I could reduce your maintenance cost by 60% ‐ what would that mean?
What does it mean to you to increase reliability and up‐time?
What would it mean to you if the service people could spend time on maintenance instead of fixing break‐downs?
Wod log handling equipment (mobile machines, see CJC Mining Cat.)
De‐barking of wood logs (bearing and gears)
Chippers and Cutters (gearbox)
Gearboxes and chip conveyor belts
Hydraulic lift for trucks, dumping wood chips
Chip feeder system (worm gear)
Digester agitator gearbox
Refiners/Defibrators/Jordan
Lube & Hydraulics Wet section
Lube & Hydraulics Drying Section incl. super calenders
Reelers & Rewinders
Wash and dewater presses
Slab and bale presses
Handling systems
Slitters
Gearboxes on agitators (aeration, water treatment)
Gas and/or steam turbine (see CJC Power Cat.)
Boiler feed pumps for steam generation (see CJC Power Cat.
22
Appendix #2 : Wood and Chips
Log handling equipment
Different types of trucks and cranes are used for moving the wood logs. They all have hydraulic systems, and may include gears and engines, which can benefit from CJC filtration.
The problem
Outdoor installation means they are exposed to the environment such as temperature changes, dust and water, which very easy find its way into the oil systems through poor breathers, worn wiper seals on hydraulic cylinder rods, shaft seals, tank openings etc.
Dirty and wet oil reduces equipment efficiency and result in short service life for the oil. Hard particles and varnish will cause servo and proportional valve to stick, resulting in unscheduled stopping of equipment. Particles will furthermore wear on pumps, which loose efficiency ‐ often 20% ‐ costing vast of energy and slow reactions of the hydraulic systems. ISO codes for cleanliness is often above ISO 22/20/16 and water above 1,000 ppm.
In order to keep these hydraulic systems reliable, it is important to keep the oil varnish free, the cleanliness at ISO 16/14/11 and moisture at max 300 ppm.
Chippers
To cut the wood into smaller chips ad Chipper is used. Often the design employs a steel disk with knives mounted upon it as the chipping mechanism. In this design, reversible hydraulically powered wheels draw the material from the hopper towards the disk, which is mounted on a perpendicular angle to the incoming material. As the disk spins, the knives cut the material into chips. They are thrown out the chute by flanges on the drum.
This design produces chips of much uniform shape and size. Most chippers currently used by commercial tree care companies are of this type. Disk‐style chippers usually have a material diameter capacity of 150 to 600 mm.
Other Style of chippers
Much larger machines for wood processing exist. "Whole tree chippers" and "Recyclers," which can typically handle material diameters of 0.5 to 2m, may employ drums, disks, or a combination of both. The largest machines used in wood processing, often called "Grinders," may handle a material diameter of 2.5m or greater, and used hardened hammers to tear wood rather than cut it. These machines usually have 500 to 1.000 KW motors on them.
Conveyor belt gearboxes
If the chipper is close to the paper plant the chips are transported to the next step in the process by means of conveyor belts, operated by electric motors and gearboxes.Each stretch of conveyor belts may have several gearboxes.
Solution: Often a HDU 15/25 or HDU27/27 are used
Hydraulic lifts for trucks
If the chipper is located far from the paper plant, the chips are loaded into truck and transported to the plant. Upon arrival the whole truck with chip containers is lifted and angled up to 45 degrees to dump the chips. This large hydraulic lifting system contains thousand liters of oil
Often ISO VG 46 from 500 to several 1,000 L hydraulic oil.
Solution: HDU 27/108 with 4xB‐inserts and 900‐1,000 l/h flow
23
Appendix #3 : Pulp
Digester
Digesting is the process of removing lignin and other unwanted wood components from the cellulose fibers, which will be used to make paper. Lignin is the "glue" which holds the wood together; it rapidly decomposes and discolors paper if it is left in the pulp ‐ as in newspapers, which are usually made from groundwood pulp with little or no chemical treatment. One of the solutions is a "kraft" mill, where the lignin is removed by the action of sodium hydroxide ("caustic soda") and sodium sulfate under heat and pressure. The chips are fed into the top of a digester and mixed with the cooking chemicals, which are called "white liquor" at this point. As the chips and liquor move down through the digester, the lignin and other components are dissolved, and the cellulose fibers are released as pulp. At the bottom of the digester, the pulp is rinsed, and the spent chemicals (now known as "black liquor") are separated and recycled or burned at the paper mill as an energy source.
At this point, the "brownstock" pulp is free of lignin, but is too dark to use for most grades of paper. The next step is therefore to bleach the pulp by treating it with chlorine, chlorine dioxide, ozone, peroxide, or any of several other treatments. A typical mill uses multiple stages of bleaching, often with different treatments in each step, to produce a bright white pulp. Chlorine bleaching generally provides the best performance with the least damage to the fibers, but concerns about dioxins and other byproducts have led the industry to move towards more environmentally friendly alternatives.As an additional information, the cellulose fibers used for CJC filters inserts are not bleached, since this destroy the strength of the cellulose.
The digestor incorporates at least two gearboxes. An agitator gearbox and a gearbox of the worm gear type for feeding chips into the digester. The agitator gearbox is cleaned best by installing a continuous CJC offline filtration,
Solution: HDU 15/25, BG15/25 insert, 45 l/h flow
The worm gear may only have 20 liters of ISO VG460 oil, so a mobile CJC filter cart is the best solution. Cleaning the oil and system often takes 2‐3 weeks, since they are so contaminated (ISO 26/25/24), have water, and lots of varnish due to the high temperature close to the steaming vessel.
Solution: HDU 27/27 mobile cart with B27/27 insert and 90 l/h flow
Refiners and defibrators
The soft “digested” chips are led to a refiner also called a defibrator, which is equipped with two rotating disks that face each other. Radial grooves are cut into the surfaces of the disks, which are driven by powerful electric motors (2,000‐4,000 kW). The chips are passed between the disks and disaggregated (ground). This is to reduce the size of the cellulose fibers and part of the process of converting wood into paper. The ground cellulose are usually fibers up to 6 mm in length and approx. 1/10 mm in width.
Digester agitator gearbox
Refiner types. See bearings on cut‐thru
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Jordan refiner
To further refine the cellulose into pulp, a Jordan is used. This breaks and de‐lump the cellulose, so the fibres can be dispersed evenly in the slurry/pulp.
The Jordan refiner consists of a conical plug which fits into a matching conical shell. The outside of the plug and the inner surface of the shell are fitted with knives or bars. The plug is pushed into the shell to the point where the knives or bars facing each other are almost touching. When fibrous stock in solution enters the shell, usually at its smaller end, the knives or bars of the rotating plug and stationary shell macerate the fibrous material and help reduce it further.
The Jordan Refiner help to brush up little hairs or fibrals on the fiber, causing the fibers to absorb large amounts of water and become more flexible and pliable. This process separates the fibers without cutting them, and result in small fiber sizes that would pass through a screen.
The lube oil in the refiner/Jordan will get wet and dirty. ISO VG 150 up to ISO VG 1000 Solution: HDU is used with 20‐50% circulation ratio or PTU2 27/27 mobile cart
Sunds Refiner with mobile PTU cart
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Appendix #4 : The Paper Machine
The paper machine is the most expensive, complex and critical machine in the paper plant. The world's largest paper machine, the Metso PM12 installed at Kvarnsveden, Sweden, is 300 meters long, 70 meters wide and 30 meters high. It has a calender width of 11.3 meters (37 ft.) and a machine speed of 2,000 meter per minute (120 km/t). The PM12 produces 420,000 tons of paper per year, and utilises 15,000 control elements handling 75,000 control signals and operates six shifts with only 9 operators per shift. The PM12 paper machine is considered to be as technically advanced as a modern jet aeroplane.
In a paper machine the “wire” is a continuous screen, where the pulp stock is sprayed onto, when the wire moves like an endless belt. Pulp stock is a slurry mixture of water and wood fibres (cellulose).
The purpose of the wire is to dry the pulp stock, so water is drained and sucked out though the wire, consisting of a porous screen/membrane, in the early days made by woven wires, hence the name.
On the wire the pulp stock dries from app. 3% solids to app. 7% solids when leaving the wire.
The drawing below shows the “head box” spraying pulp stock onto “the wire”.
Today paper machine manufactures have improved the traditionally “wire” to include two wires pressed against each other ‐ “Twin wire formers”.
Instead of putting the pulp stock onto a single horizontal wire, the stock flows from the head box through a slit between two (downward) vertically moving wires. These two wires form a nip in between them (a fine clearance). At this nip, suction is applied to one wire so that the web (or "sheet") adheres to that wire. That wire then moves forward to the press section of the paper machine. This innovation enable paper machines to move at much higher speeds and to yield better sheet formation.
The PM wet end will get water into lube/gear oil. The main lube system consists of 5,000 ‐ 30,000 L oil, typical ISO VG 220 ‐ 460 of PM oil. Since PM oils create emulsions with water a CJC PTU cannot be used
Solution: HDU with BLA and D30 or D40 is used. 10‐15% circulation ratio for HDU. Desorber according to oil volume.
Hydraulic system on wet end is mostly ISO VG 46 and contains from 1,000 ‐ 3,000 liter. Most often we can utilize PTU. Circulation ratio of 15% of oil volume per hour ‐ max 800 L/h per PTU27/108.
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Paper drying
When the paper sheet enters the drying section of the paper machine, it contains about 50% of water. The paper must be dried to less than 10% of water for a final product. The most common drying sections include steam cylinders and air dryers. Infrared dryers are most commonly used on coating lines.
Drying occurs in three phases or zones (heating phase, constant rate zone and falling rate zone). In the heating phase the sheet enters at about 38°C and is brought up to about 80°C. Generally, the first 5 cylinders are considered as the heating phase. In the constant rate zone, heat is added at about the same rate that evaporation is removing the heat. Most of the water is removed in the constant rate zone. The falling rate zone is the most difficult as it must remove the last 10% or so of moisture without causing problems related to un‐even or over‐drying.
Dryer Types
Steam Cylinders
Steam cylinders are 1,2 to 1,6 metres in diameter and slightly longer than the width of the paper sheet. A typical paper machine has 40 to over 100 steam cylinders, depending on the line speed (normally about 1500 and up to 2000 metres per minute); the faster the line speed, the longer the drying section. Paper machines are as long as a football field and 3 to 5 stories tall.
Air Dryers
Air dryers are direct fired or use steam‐to‐air heat exchangers to produce a hot air stream that is forced over the surface of the paper. Hoods or caps are used to contain and direct the air flow. Air dryers tend to be used on lighter weights of paper, such as tissues, and to supplement the drying of steam cylinders.
A yankee dryer is a specific kind of dryer used most commonly for tissue and toweling manufacturing that combines a large steam cylinder and an air hood.
The flakt pulp dryer is also a special kind of air dryer that is used to dry market pulp (Pulp that is made in one location and sold for final paper manufacturing at another location). A flakt dryer is constructed in decks that the pulp serpentines through as hot air is blasted through it by a series of jets.
Super calenders
The calendering process is one of the final processes before eventually given a surface treatment with a coating.
Most paper machines utilise 6 to 10 high‐precision Super calender rolls (SYM‐CD by Metso) with narrow zone profiling to produce paper with a higher gloss and smoother surface. CD stands for Cross Direction and the CD‐roll is a device that corrects the cross directional errors on the paper web. Each super calender contains up to 76 hydraulic pistons placed inside each roll to exert forces at each load zone to maintain a controlled profile across the complete width of the roll. These forces are hydrostatically counterbalanced on the opposite side of the roll. The force exerted by each piston is controlled by a Moog Servo valve and the pressure in the counterbalance zones with Servo‐Proportional Valves. In addition, four Moog Servo valves control the hydrostatic bearings located at either end of each roll.
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The calendering gives the paper its surface which is different depending on the final use i.e. news paper, glossy magazines etc.
Oil systems in the dryer section.
In the drying section there are two main oil systems.
1. A lubricating system for the bearings and for the internally gears in the rolls.
2. A hydraulic system to controlled profile across the width of the roll and additionally hydraulic components including super calenders
A paper machine is producing paper 24 hours a day and it is therefore important that the machinery is able to work without breakdown. Breakdowns generated from components in the different oil systems. The constantly increasing demands by larger, faster machines, higher steam temperatures and more accurate paper thickness/finish, will add to the challenge on the lubricant and lubrication delivery system.
Lube oil for roll‐neck bearings and internal gears
The rolls in the drying section of the paper machines are normally driven by an electric motor over a gear internally in the roll. A few paper machines don’t have gear between the rolls and the electric motor, but are driven directly by the motor. The gears internally in the rolls are lubricated from the main lube oil system. Oil volume: The main lube system normally contains 3,000 to 10,000 liters of oil.
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Bearings
Previously grease was used in the bearings of the rolls on the drying section of a paper machine. Today the rolls are lubricated with oil from a main lube oil system. By using a main lubricating system, the generated heat from the steam in the rolls, can be transported away by a flow of clean oil and thereby reduce the wear in the bearings.
The bearings are expensive spherical roller bearings costing 6,000‐8,000 EUR each (two per roll).
If the rolls are put on stock with wet oil in the bearings, they will corrode and more than 50% of the life will be lost. A Tonning Troley, PTU27/27 on tank, can be sued to dry the oil in the bearings before storage.
Hydraulic oil system
The hydraulic system for the super calenders contain hundreds of sensitive valves, cylinders etc., which can easily seize by particles, water or varnish. The largest hydraulic systems incorporate up to 600 valves in the drying section.
Oil volume is normally 10.000 to 20.000 liters of oil.
Solution: 15% circulation ratio of oil per hour for HDU often HDU27/108 or VRU if the system has large varnish issues.
The mentioned oil systems are only the main oils systems of the drying section. Depending of the machinery type and producer the oil systems will vary and include more systems.
Yankee press
In the manufacturing of tissue paper or paper towels one large dryer cylinder, known as a Yankee dryer, is employed. Yankee dryers vary in size from 5 ‐ 8 meters in diameter depending on the size of the paper machine. The paper sheet passes around a pressure roll, which presses the sheet against the Yankee dryer roll, so the sheet adheres to the dryer surface. As the sheet rotates around, it is eventually scraped off by a metal blade known as a crepe blade or “doctor”.
The drying operation is a short and intensive process and the Yankee dryer must perform well in all its functions. For conventional dry crepe machines, the system consists of a Yankee dryer and associated high velocity, high temperature impingement hood. It is a complex mechanical structure, exposed to steam pressure, and there are extremely high demands on safety and operational reliability.
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Appendix #5 : Paper Finishing and handling
Reelers and roll rewinders
For easy storage and handling, the finished paper is most often wound onto large rolls when coming off the last dryer of the paper machine. This is referred to as a “winder”. Rewinders rewind the roll off the original winder. Because it is difficult to retain perfect consistency of thickness and grain when the sheet is being wound on directly off the machine onto the first winder, rewinding the sheet can help even out stretches and crooked sheets and other imperfections.
It is very important that the paper is wound tight on the roll to prevent slippage of layers and the resultant crepe wrinkles and uneven gloss.
Some paper machines incorporate “multi station winders”, which wind more rolls at the time for higher speed. Up to 500 l of gear/hydraulic oil. Solution: CJC HDU 27/54?
Slab and bale presses
These presses are designed to press pulp into large dry slabs or bales, which can be shipped to customers without the need to transport water.
The slab pressure uses large hydraulic systems to farce the cellulose into the “mold”.
The hydraulic oil is stressed by fast cycle time, often less than 15 seconds, plus the oil is contaminated with dust, wear particles and water. This combined with hot spots of high temperatures will degrade the oil, create varnish, which reduce availability and accuracy of the press (servo valves and hydraulic motors).
CJC filters uses different types of cellulose for filter production, where the raw material come in large slabs, which we dissolve in water to produce CJC filter inserts.
Oil volume: 3,000 ‐ 5,000 L hydraulic ISO VG 46‐58
Solution: For systems with constant high oil temperature a VRU 27/108 is the best CJC product
On systems with alternating temperatures, a HDU 27/108 with B‐inserts can do a fine job.
Case Sunds slab press, BC Canada
Oil volume: 4,500 L ISO VG 68
VRU trial period of 3 months on the hydraulic oil. After only 3 weeks the oil improved significantly
Particle reduction using the VRU during 3 weeks see particle count per ml.
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87% reduction of 4‐micron size particles 88% reduction of 6‐micron size particles
The conclusion based on the results
No oil chance was needed (4.500 L x 5 USD = 22,500 USD), no downtime and less wear on components.
On top of this the paper mill reduced their consumption of inline filters for the press during the 3‐month test period, which means from 117 to 54 per year, each filter costing 400 USD ‐ equal to 25,000 USD for filter saving alone. That alone paid for the VRU, so the client bought it and ordered two VRU more!
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Appendix #6 : Water treatment
The effluent water coming from the Paper plant need to be treated. Large pools containing bacteria is breaking down the effluent, so it can run off to rivers/lakes. If the agitator’s stops it means the bacteria will die and new ones can take up to one year to reproduce ‐ during this time the paper plant will need to run less speed/output.
The agitator is driven by an electric motor connected to a gear box. Outdoor exposure to dust and water wear on the oil and gear. The gear can develop lots of heat under heavy load, which degrade the oil fast.
Oil volume: 50 ‐ 200 L of ISO VG 150 ‐ 320 gear oil
Solution: HDU 15/25 with BG insert and 45 l/h flow on each agitator gear is a cheap safety.