Creping
The crepe blade is the point at which the final sheet appearance is created. The geometry of the blade and its application are critical in establishing the best possible end product. Specifically designed for tissue applications, the crepe blade, along with the Yankee against which it operates, is the heart of the process.
The doctor holder uses a special pneumatic loading arrangement to load the blade against the Yankee cylinder and has a “flexible finger” type backing. The mechanical lock prevents collision of the holder with the cylinder when there is no blade in place. For certain applications and upon request, a stiff holder can be substituted.
Angle adjustment
The doctor assembly is adjustable for different applications and end product properties. The entire assembly can be rotated on the assembly journal by means of a jacking bolt that changes the position of the assembly relative to the loading cylinder stroke.
At a glance
Flexible holder ensures even application of the creping load.
Adjustable angular position allows flexibility for different products and properties.
Wrinkles & Piping in paper reels is an annoying problem. When the reel is used for any conversion, printing, lamination or anything, you get rejects and rejects. This presentation gives some thoughts on how can we minimize wrinkles and piping.
Creping
The crepe blade is the point at which the final sheet appearance is created. The geometry of the blade and its application are critical in establishing the best possible end product. Specifically designed for tissue applications, the crepe blade, along with the Yankee against which it operates, is the heart of the process.
The doctor holder uses a special pneumatic loading arrangement to load the blade against the Yankee cylinder and has a “flexible finger” type backing. The mechanical lock prevents collision of the holder with the cylinder when there is no blade in place. For certain applications and upon request, a stiff holder can be substituted.
Angle adjustment
The doctor assembly is adjustable for different applications and end product properties. The entire assembly can be rotated on the assembly journal by means of a jacking bolt that changes the position of the assembly relative to the loading cylinder stroke.
At a glance
Flexible holder ensures even application of the creping load.
Adjustable angular position allows flexibility for different products and properties.
Wrinkles & Piping in paper reels is an annoying problem. When the reel is used for any conversion, printing, lamination or anything, you get rejects and rejects. This presentation gives some thoughts on how can we minimize wrinkles and piping.
Drive Power and Torque in Paper Machine DryersKadant Inc.
basic parameter in the design of a paper machine dryer drive system, whether it has an open gear, enclosed gear, or felt drive, is the drive power requirement. Previous work on the drive power for paper machine dryers covered a 1.5 meter diameter cylinder. This paper presents the results for both 1.5 and 1.83 meter diameter cylinders with and without dryer bars.
Single-felt dryer sections are used to enhance the runnability of high-speed paper machines. In single-felt dryer sections, the web is supported by the dryer felt (i.e., fabric) in the draws between dryers. Fabric style, air handling equipment, and runnability devices are critical to efficient operation. Steam control in bottom single-felt dryers is also important.
Suggestive Improvements in Yankee Internal DesignDevesh Singhal
The object of this presentation is to indicate possible improvements by which condensate removal efficiency of yankee cylinder (MG cylinder, as commonly called in India) can be improved.
Drying training Equipment Operation and control Nelson Izaguirre
No manufactured product plays a more significant role in every area of human activity than
paper and paper products. Its importance in everyday life is obvious from its use in
recording, storage and dissemination of information. Virtually all writing and printing is
done on paper. It is the most widely used wrapping and packaging material, and is
important for structural applications. The uses and applications for pulp and paper
products are virtually limitless. Apart from the products and services that it provides, the
paper and pulp industry is one of the major manufacturing industries in the world
providing employment for vast number of people and contribute to national economy.
The paper making process is essentially a very large dewatering operation where a diluted
solution of pulp suspension with less than 0.5% fibre solid is used. The major sections of a
paper machine consist of: forming section, press section and dryer section. In the forming
section, the fibres present in the diluted pulp and water slurry form paper web through
drainage by gravity and applied suction below the forming fabric. In the press section
additional water in removed by mechanical pressure applied through the nips of a series of
presses or rotating rolls and the wet web is consolidated in this section. Most of the
remaining water is evaporated and inter-fibre binding developed as the paper contacts a
series of steam heated cylinder in the dryer section. Water removal from the wet web to the
final moisture level between 6% and 7% is a critical step of papermaking. Majority of the
functional properties of paper are developed in this section.
In spite of its key role in papermaking, large equipment size, and large capital and operating
costs, drying is arguably the least understood papermaking operation. Books on
papermaking technology generally devote fewer pages to drying than other papermaking
operations such as forming, pressing or calendaring. A similar situation is found in
papermaking courses, in which drying occupies a shorter time than the proportion of space
it takes in a paper machine. Furthermore, a large portion of that time is devoted to the
description of the equipment by its suppliers rather than to its operation by the
papermakers.
Crescentformer general process. tissue machine VoithNelson Izaguirre
CRESCENT FORMER
The Crescent Former is the culmination of technological improvements derived from our experience in the manufacturing of four machines since the 1960s (Plain Wire; Sloped Wire; Twin Wire C-Former; and Twin Wire S-Former). The first Crescent Former was invented in the 1970s by the multinational Kimberly Clark which held the patent until the Nineties.
Our technological innovations and more than 50 years of experience in the field of tissue ensure the highest levels of performance from the Recard Crescent Former.
Each Recard Crescent Former is designed to optimize the real operating speed of your production line. We have achieved performance of over 2000 meters per minute.
Paper dryers are occasionally shut down for periods of time ranging from a few hours to many months. It important that proper procedures be followed when shutting down dryers to be sure that the process is complete and appropriate for the duration of the shutdown.
Vibration Characteristics in Cantilever Stationary SyphonsKadant Inc.
Most high-speed paper machine dryers operate with stationary cantilever syphons and dryer bars. Modern cantilever stationary syphons are rigidly mounted to the dryer bearing housings and they provide a reliable system of support. Dryer bars provide for high rates of heat transfer with excellent heat transfer and profile uniformity.
Dryer Condensing Loads Following Sheet BreaksKadant Inc.
Tests were conducted at the Kadant Johnson Research Center in Three Rivers, Michigan USA to directly measure the rate of condensate evacuation from dryers with different control strategies in response to a sheet break and recovery.
DIY guidelines for optimization of wire vacuumDevesh Singhal
This presentation indicates how paper mills can collect data from their own machines and do the optimization to reduce energy consumption and get more dryness after the wire part.
Heat Transfer Performance with Dryer BarsKadant Inc.
Dryer bars are used in paper machine drying cylinders to increase the rate of heat transfer and uniformity of drying. This paper has outlined an introduction to the technology of dryer bar design and presents the factors to be considered to achieve optimum performance.
Drive Power and Torque in Paper Machine DryersKadant Inc.
basic parameter in the design of a paper machine dryer drive system, whether it has an open gear, enclosed gear, or felt drive, is the drive power requirement. Previous work on the drive power for paper machine dryers covered a 1.5 meter diameter cylinder. This paper presents the results for both 1.5 and 1.83 meter diameter cylinders with and without dryer bars.
Single-felt dryer sections are used to enhance the runnability of high-speed paper machines. In single-felt dryer sections, the web is supported by the dryer felt (i.e., fabric) in the draws between dryers. Fabric style, air handling equipment, and runnability devices are critical to efficient operation. Steam control in bottom single-felt dryers is also important.
Suggestive Improvements in Yankee Internal DesignDevesh Singhal
The object of this presentation is to indicate possible improvements by which condensate removal efficiency of yankee cylinder (MG cylinder, as commonly called in India) can be improved.
Drying training Equipment Operation and control Nelson Izaguirre
No manufactured product plays a more significant role in every area of human activity than
paper and paper products. Its importance in everyday life is obvious from its use in
recording, storage and dissemination of information. Virtually all writing and printing is
done on paper. It is the most widely used wrapping and packaging material, and is
important for structural applications. The uses and applications for pulp and paper
products are virtually limitless. Apart from the products and services that it provides, the
paper and pulp industry is one of the major manufacturing industries in the world
providing employment for vast number of people and contribute to national economy.
The paper making process is essentially a very large dewatering operation where a diluted
solution of pulp suspension with less than 0.5% fibre solid is used. The major sections of a
paper machine consist of: forming section, press section and dryer section. In the forming
section, the fibres present in the diluted pulp and water slurry form paper web through
drainage by gravity and applied suction below the forming fabric. In the press section
additional water in removed by mechanical pressure applied through the nips of a series of
presses or rotating rolls and the wet web is consolidated in this section. Most of the
remaining water is evaporated and inter-fibre binding developed as the paper contacts a
series of steam heated cylinder in the dryer section. Water removal from the wet web to the
final moisture level between 6% and 7% is a critical step of papermaking. Majority of the
functional properties of paper are developed in this section.
In spite of its key role in papermaking, large equipment size, and large capital and operating
costs, drying is arguably the least understood papermaking operation. Books on
papermaking technology generally devote fewer pages to drying than other papermaking
operations such as forming, pressing or calendaring. A similar situation is found in
papermaking courses, in which drying occupies a shorter time than the proportion of space
it takes in a paper machine. Furthermore, a large portion of that time is devoted to the
description of the equipment by its suppliers rather than to its operation by the
papermakers.
Crescentformer general process. tissue machine VoithNelson Izaguirre
CRESCENT FORMER
The Crescent Former is the culmination of technological improvements derived from our experience in the manufacturing of four machines since the 1960s (Plain Wire; Sloped Wire; Twin Wire C-Former; and Twin Wire S-Former). The first Crescent Former was invented in the 1970s by the multinational Kimberly Clark which held the patent until the Nineties.
Our technological innovations and more than 50 years of experience in the field of tissue ensure the highest levels of performance from the Recard Crescent Former.
Each Recard Crescent Former is designed to optimize the real operating speed of your production line. We have achieved performance of over 2000 meters per minute.
Paper dryers are occasionally shut down for periods of time ranging from a few hours to many months. It important that proper procedures be followed when shutting down dryers to be sure that the process is complete and appropriate for the duration of the shutdown.
Vibration Characteristics in Cantilever Stationary SyphonsKadant Inc.
Most high-speed paper machine dryers operate with stationary cantilever syphons and dryer bars. Modern cantilever stationary syphons are rigidly mounted to the dryer bearing housings and they provide a reliable system of support. Dryer bars provide for high rates of heat transfer with excellent heat transfer and profile uniformity.
Dryer Condensing Loads Following Sheet BreaksKadant Inc.
Tests were conducted at the Kadant Johnson Research Center in Three Rivers, Michigan USA to directly measure the rate of condensate evacuation from dryers with different control strategies in response to a sheet break and recovery.
DIY guidelines for optimization of wire vacuumDevesh Singhal
This presentation indicates how paper mills can collect data from their own machines and do the optimization to reduce energy consumption and get more dryness after the wire part.
Heat Transfer Performance with Dryer BarsKadant Inc.
Dryer bars are used in paper machine drying cylinders to increase the rate of heat transfer and uniformity of drying. This paper has outlined an introduction to the technology of dryer bar design and presents the factors to be considered to achieve optimum performance.
Dryer doctors have a number of purposes in a paper machine dryer section: sheet shedding, dryer surface cleaning, threading, and air handling and control. Paper dryer doctors are often overlooked in the papermaking process, but they need proper attention to maintain efficient dryer operation.
The concept of an improved dryer control system is to utilize modern control capabilities to provide supervisory control over the steam control and dryer drainage system.
Controlling Cavitation in Industrial Control ValvesCTi Controltech
Cavitation, in process control valves, refers to the formation of vapor spaces or bubbles within the valve cavity resulting from a rapid drop in pressure as liquid passes through the valve. When the bubbles transit to an area of higher pressure, the higher pressure causes the bubbles to implode, producing shockwaves which propagate through the liquid. These shockwaves can cause metal fatigue and excessive wear on the internals of the valve. The collapsing bubbles also make a discernible sound with accompanying vibration.
Flowserve provides an introduction to cavitation with velocity profile, pressure profile, effects of cavitation, flashing, sound, and other aspects covered. The theory behind controlling cavitation and various methods employed in the company's valve products is also included.
Cavitation Reduction in Industrial Process Control ValvesCTi Controltech
In many control valves, the pressure at the vena contracta
will drop below the vapor pressure of the liquid. When
this occurs, small bubbles of gas will form as the liquid
vaporizes. As the pressure then rises above the vapor
pressure again, these small bubbles collapse or implode
as the vapor turns back into liquid. The damage is inflicted
as the bubbles implode. The implosion of the vapor
bubbles is very energetic and forms jets of fluid which can
tear small pits into the metal. This is called cavitation.
Cavitation damage destroys both piping and control
valves, often resulting in catastrophic failure. It causes
valves to leak by eroding seat surfaces. It can drill holes
through pressure vessel walls. Even low levels of cavitation
will cause cumulative damage, steadily eroding parts
until the part is either repaired, or it fails.
This Slideshare explains valve cavitation and provides solutions to minimize or eliminate its effects.
Cavitation is a phenomenon that can occur in a liquid process whenever there is a drop in pressure. Cavitation should be avoided, since it produces destructive forces in the liquid that damage valves, pumps, and other equipment.
The primary function of a utility boiler is to convert water into steam to be used by a steam turbine/ generator in producing electricity. The boiler consists of a furnace, where air and fuel are combined and burned to produce combustion gases, and a feedwater tube system, the contents of which are heated by these gases.
Home Made Hydraulic Ram Pump - Part 1
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For more information, Please see websites below:
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Organic Edible Schoolyards & Gardening with Children =
http://scribd.com/doc/239851214 ~
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http://scribd.com/doc/239851079 ~
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Free School Gardening Art Posters =
http://scribd.com/doc/239851159 ~
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Increase Food Production with Companion Planting in your School Garden =
http://scribd.com/doc/239851159 ~
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Healthy Foods Dramatically Improves Student Academic Success =
http://scribd.com/doc/239851348 ~
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City Chickens for your Organic School Garden =
http://scribd.com/doc/239850440 ~
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Huerto Ecológico, Tecnologías Sostenibles, Agricultura Organica
http://scribd.com/doc/239850233
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Simple Square Foot Gardening for Schools - Teacher Guide =
http://scribd.com/doc/239851110 ~
Process Profiling: Investigation And Prediction Of Process Upsets With Advanc...Jim Cahill
2009 HART Plant of the Year Award winner Mitsubishi Chemical Corporation Uses HART Technology to Detect Abnormal Situations and Failures before they Affect the Process
http://hartcomm.org/protocol/realworld/realworld_success_mitsubishi09.html
In this day and age of automated computer control valve sizing, the logic and theories behind it are invisible. In his presentation, Al Holton of Allagash Valve & Controls will look at the basic principles that apply and how they affect the application and installation of a wide range of control valve types. He will also review the reasoning behind valve type selection.
Stack height often surprises me. Can we consider cutting short stacks of factories to reduce pollution, as the polluter would be faced to get into self compliance, willingly or unwillingly. Think.
Can we provide some space for viruses in our lives? A different thought, indicating what can be done to to live happily without a fear of virus and let it live its life.
Delhi-NCR air is becoming more and more polluted. We need to find a solution, that too very fast. The present concept note presents such a simple idea to solve the pollution problem.
When environment protection causes problemsDevesh Singhal
What happens when an industry starts treating effluent to achieve better and better than mandated norms? This is done by additional energy, capital cost and thus creates undesirable problems.
Voltage fluctuations and hence motor tripping is a serious problem particularly during rainy season. This presentation is just a small initiative to think and explore what can we do to reduce the problem.
Can our cooking create pollution?
While you prepare your delicious food, fumes containing particulate matter are added to atmosphere. Probably that is the reason that pollution index is generally found more in densely populated areas.
Have you faced problems of incorrect readings in displays, flickering of tubelights etc. Do you know, electrical pollution can be harmful for our lives also?
UiPath Test Automation using UiPath Test Suite series, part 4DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 4. In this session, we will cover Test Manager overview along with SAP heatmap.
The UiPath Test Manager overview with SAP heatmap webinar offers a concise yet comprehensive exploration of the role of a Test Manager within SAP environments, coupled with the utilization of heatmaps for effective testing strategies.
Participants will gain insights into the responsibilities, challenges, and best practices associated with test management in SAP projects. Additionally, the webinar delves into the significance of heatmaps as a visual aid for identifying testing priorities, areas of risk, and resource allocation within SAP landscapes. Through this session, attendees can expect to enhance their understanding of test management principles while learning practical approaches to optimize testing processes in SAP environments using heatmap visualization techniques
What will you get from this session?
1. Insights into SAP testing best practices
2. Heatmap utilization for testing
3. Optimization of testing processes
4. Demo
Topics covered:
Execution from the test manager
Orchestrator execution result
Defect reporting
SAP heatmap example with demo
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
Encryption in Microsoft 365 - ExpertsLive Netherlands 2024Albert Hoitingh
In this session I delve into the encryption technology used in Microsoft 365 and Microsoft Purview. Including the concepts of Customer Key and Double Key Encryption.
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
The Art of the Pitch: WordPress Relationships and SalesLaura Byrne
Clients don’t know what they don’t know. What web solutions are right for them? How does WordPress come into the picture? How do you make sure you understand scope and timeline? What do you do if sometime changes?
All these questions and more will be explored as we talk about matching clients’ needs with what your agency offers without pulling teeth or pulling your hair out. Practical tips, and strategies for successful relationship building that leads to closing the deal.
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
Kubernetes & AI - Beauty and the Beast !?! @KCD Istanbul 2024Tobias Schneck
As AI technology is pushing into IT I was wondering myself, as an “infrastructure container kubernetes guy”, how get this fancy AI technology get managed from an infrastructure operational view? Is it possible to apply our lovely cloud native principals as well? What benefit’s both technologies could bring to each other?
Let me take this questions and provide you a short journey through existing deployment models and use cases for AI software. On practical examples, we discuss what cloud/on-premise strategy we may need for applying it to our own infrastructure to get it to work from an enterprise perspective. I want to give an overview about infrastructure requirements and technologies, what could be beneficial or limiting your AI use cases in an enterprise environment. An interactive Demo will give you some insides, what approaches I got already working for real.
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Here’s what you’ll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
2. Problem:
How do you control basis weight?
Basis weight valve
Stock flow to fan pump
Machine chest consistency control
3. Problem:
What are modern techniques for basis
weight control?
Automatic machine chest consistency
control
Scanner controlling basis weight valve
Having a DCS/QCS system
4. Is it Really a Problem?
Maintaining correct basis weight is the
duty of machine operator.
If he is careless, we can have good
scanners, DCS/QCS systems.
Why should we waste our precious time
discussing such small things?
5. Yes!
Yes! It IS a genuine problem.
Please do spare a few minutes now.
6. Problem:
In fact, basis weight variation is a
common problem in all the mills.
Some mills manage to get the best
results out of their system.
Let us have a look at various points that
are the possible sources for poor basis
weight control.
7. Possible Sources for Poor
Control
Machine Chest
Centricleaner
Pressure Screen
Approach Flow Piping
Approach Flow Pumps
Head Box Manifold
Distributor-Rectifier Rolls
Electricity Supply System
8. Machine Chest
Machine chest consistency plays its own
role.
Too high a consistency results in fiber
flocculation as well as air entrapment in
pulp which creates a lot of problems in the
approach flow area.
In case consistency is too low, pulp fibers
tend to settle down resulting in changing in
SRBox consistency over a period of time.
9. Centricleaner
In the conventional centricleaners,
pulp enters from one side, it goes to
centricleaner bottles, and then leaves
through accept of these bottles.
Final accept is also at the same side.
This results in slow response of inlet
consistency change as shown in next
slide.
11. Pressure Screen
Similarly, pressure screen is also a
huge vessel resulting in a similar
response as that by centricleaner.
The only difference is that the outlet
consistency plot will look a little
smooth when compared to that with
plot of centricleaner.
12. Approach Flow Piping
Approach flow piping may create
problems if not properly designed.
For example, let us consider line from
S R Box to fan pump. An oversized
line results in too slow pulp speed
vertically downwards.
This results in plug flow where pulp
flows in form of a plug. (Remember:
pulp is not an ideal liquid)
13. Approach Flow Piping
During the plug flow, plug like structure is
developed in pipeline. These plugs are
intermittent in nature as a combination
separate plugs one after another.
When it happens, we get intermittent pulses
of consistency fluctuation after the fan
pump.
This results in basis weight fluctuation.
14. Approach Flow Piping
On the other hand, if the pulp velocity
is too high (i.e. pipeline is undersized),
pulp starts to show erratic behavior.
In such a case any change in basis
weight valve opening may not reflect
proportional change in stock flow and
hence basis weight.
15. Approach Flow Pumps
All the pumps used in approach flow
should be of low pulsation type.
Pressure pulses travel at a speed
much higher than that of pulp (almost
equal to the speed of sound) and
create fluctuation in basis weight.
16. Approach Flow Pumps
Pumps must be regularly checked for
gland leakage etc.
Leaking glands are often the easiest
entry point for entrained air.
This entrained air creates
unpredictable fluctuations in basis
weight.
17. Head Box Manifold
As discussed earlier, most of the
machine direction changes, be these
due to consistency change, or due to
any other reason, or the desired
change in basis weight valve, enter
the manifold where these are
converted to cross direction changes
as indicated in nest slide.
20. Manifold:
Octopus header can be used to avoid
CD profile fluctuations related
problems in place of taper manifold.
21. Distributor-Rectifier Rolls
Distributor rectifier rolls (commonly
known as holey rolls) could be a major
reason for basis weight fluctuation.
In most of the cases, the head box
manufacturer gives very good rolls,
but with time, some rolls get bend,
misaligned or due to journal wear out,
bearing related problems, the
problems start appearing.
22. Distributor-Rectifier Rolls
Time series analysis (plotting machine
direction basis weight at a single CD
position against time) is an effective
tool to predict holey roll related
problems.
23. Checking for Holey Roll Related
Problems:
For the same, at least three 2 minute MD
profiles are taken, one each at NDE, center
and DE.
Higher fluctuation amplitude at center
indicates bend holey roll.
Higher fluctuation amplitude at any end
indicates the possibility of bearing off-center
at that end.
After the problem has been identified and
rectified, it is recommended to verify the
results by repeating the measurements.
25. 35.50
35.30
A 45 second profile:
35.10
34.90
34.70
34.50
34.30
34.10
33.90
33.70
33.50
1
9 17 25 33 41 49 57 65 73 81 89 97 105 113 121 129 137 145 153 161 169 177 185 193
Such a profile can reveal a lot of
information.
The trend line (red color) indicates different
high basis weight pulses. These are
indicated by vertical lines in the plot. These
correlate to revolutions of holey roll.
There are minor pulses also in the graph,
which might be due to pulsations caused by
holes or something else.
26. Holey Roll:
Unfortunately, these run at much less speeds
say 10-15rpm, and may result in pulsations at
after 15-20m distance. The one minute MD
profile is often able to reveal if a particular holey
roll is bend or misaligned.
Single Position MD Prof ile
140.0
Possibily due to testing error .
135.0
Stable
130.0
Stable
Stable
125.0
16
9
11
8
16
6
11
5
16
3
11
2
16
0
9
1
7
6
6
1
4
6
3
1
1
6
1
120.0
27. Typical Inferences:
A bend/misaligned holey roll
To high holey roll speed
If the fluctuation is not of the same
magnitude after each holey roll
revolution, there is a possibility of
loose chain/ chain sprocket driving the
holey roll.
28. Typical Solution:
In one instance, while checking approximately
200 samples during the machine run of one
minute, the fluctuation in basis weight was
found to be within + 0.5gsm.
On the basis of the same, holey roll speed was
reduced from 22 rpm to 11 rpm.
The fluctuation immediately reduced to
+0.23gsm.
Well, in many cases, repair or replacement of
holey roll becomes a must to get good basis
weight control.
29. Electricity Supply System
Speed of approach flow equipments vary due to
voltage and frequency variations.
Servo voltage stabilizer is able to control voltage to a
maximum of ±2.5% only.
Frequency variations, (≈2%) remain uncontrolled.
Net effect: ±4.5% (i.e.fan pump speed may vary by
±75rpm if running at full speed of 1440 rpm)
One may very well understand the effect of such level
of uncontrollable speed variation of fan pump and
other approach flow equipments on basis weight.
30. Fan Pump Speed:
Installation of VFD will be helpful in
eliminating this problem.
So far, most of the VFD installations
are aimed towards energy
conservation, but in approach flow
area, the improved process control is
greatest advantage of VFD.
31. Entrained Air:
Creates disturbance! Irregularly.
Problem worsens if there are dead pockets.
Much more severe in improperly designed
pipings.
Often serious on light gsm paper, when the
speed is higher.
Analog (bourdon Tube) gauges do not reflect
pressure fluctuations.Digital pressure gauges
with large diameter transmitters do help.
Profile unstability Analysis
• A higher value at stock entry side indicates possibility of
entrained air.
• More joints from this side.
32. Let us now have a look at typical
basis weight profile…..
38. Now, may we ask?
Were the operators careless?
Was there so high a stock consistency
variation?
Or, there was something else
responsible for the problem?
39. Let us try something…
Out of the available 24 consequent
profiles, we take average at different
positions. Similarly, position wise
minimum and maximum values can
be found out.
The values are plotted as in next
figure.
41. 135.0
130.0
125.0
120.0
115.0
110.0
105.0
1
2
3
4
Min
5
Max
6
7
Avg.
In fact, such a stable averaged profile (Green)
suggests the absence of any CD problem in
machine. Typically, disturbed average profile
can also be due to various reasons such as
localized wire and felt choking, head box slice
unevenness, drying constraints etc.
All of such factors force machine operators to
disturb CD profile so that they are able to
maintain CD moisture profile in acceptable
range.
8
9
42. Another Profile Report
Let us study the another profile study,
consisting of 45 profiles.
All of these profiles were drawn from a
single roll.
These profiles are taken within 1
minute of production.
For simplicity, instead of giving a lot of
data, preliminary profile analysis is
presented in form of a graph.
44. Best & Worst CD Profiles
Profile Variation:
39
38
37
36
35
34
33
32
1
2
3
4
5
6
7
8
9
10 11 12
Here, we may see an interesting pattern.
Out of the 45 profiles taken from a single
roll, we may get CD variations of 2.0 and
4.0.
So, how much CD variation we are
getting is depending on our luck. Within
a span of one minute, we may get a
profile variation of 2.0 or 4.0 gsm.
45. Range of GSM Obtained at
Different Positions:
40
38
36
34
32
1
2
3
4
5
6
7
8
9
10 11 12
46. Range of GSM Obtained at
Different Positions:
40
38
36
34
32
1
2
3
4
5
6
7
8
9 10 11 12
Here again the situation is same.
As clear, there is a variation of 2 gsm at
any individual position.
Obviously, if the operators are drawing
sample at any instance, there is always a
possibility of 2gsm inaccuracy in
measurement, no matter however
accurate is the measuring system.
47. Average GSM as a Function
of Time
37
36.5
36
35.5
35
34.5
34
1
5
9 13 17 21 25 29 33 37 41 45
48. Average GSM as a Function
of Time (after modification)
45.4
45.3
45.2
45.1
45
44.9
44.8
44.7
44.6
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
49. Average GSM as a Function
of Time
37
36.5
36
35.5
35
34.5
34
1
5
9 13 17 21 25 29 33 37 41 45
Here we can see that the average gsm is
fluctuating significantly.
Suppose the desired basis weight is 36,
and operator is getting anything as
above, the problem appears should he
alter basis weight valve opening or
ignore the difference?
You decide!
50. What is so special in these
profiles?
Best & Worst CD Profiles
Range of GSM Obtained at Different Positions
39
38
37
36
35
34
33
32
40
38
36
34
32
1
2
3
4
5
6
7
8
9
10 11 12
Average GSM as a Function of Time
37
36.5
36
35.5
35
34.5
34
1
5
9 13 17 21 25 29 33 37 41 45
1
2
3
4
5
6
7
8
9
10 11 12
51. Time is Short….
All these profiles have been taken from a
SINGLE roll, one after another.
For a machine speed of 200mpm, and roll
diameter of nearly 1M, this can be said that
these profiles are one second apart from
each other.
Thus, 45 profile means nearly 45 seconds
of production.
If, basis weight can fluctuate between 34.0
to 36.5 within a short span of 45 seconds,
how can we expect to control the same?
52. Scanner Malfunctioning…
The most important aspect about such a
case is that the basis weight scanners
installed for DCS & QCS systems seem to
malfunction. You may take a sample which
could be 34.0gsm or 36.5gsm, and most
probably the DCS system would be
displaying some other basis weight on its
console.
In such a case, most papermakers will say
that the scanner is giving wrong results.
So, if you are not satisfied with your
scanner, please read ahead.
55. Scanner Malfunctioning…
Scanners work on a scientific principle of
radioactive rays penetration properties of
cellulose fibers.
A calibration problem may result in over or
under reporting of basis weight, and this can be
corrected easily.
But, in case there is a fluctuation in basis
weight as seen earlier, one may doubt that the
scanner is not functioning well.
56. Advantages of Such
Analysis:
It is possible to analyze different
reasons and their contribution to
existing basis weight variation
problem.
Common inferences that can be
drawn by such study are..
57. Typical Inferences:
A bend/misaligned holey roll
Entrained air in approach flow
systems
Inadequate inlet pressure at pressure
screen inlet
Centricleaner pit level and
consistency fluctuations
58. In House Troubleshooting:
Single position MD profiling has been
found a very good technique for such
problems.
The following slides indicate how you
may use this technique to solve basis
weight related problems in your plant.
59. Single Position MD Profiling:
Single position MD profiling is a technique,
in which data are obtained for basis weight
profile in machine direction, and plotted
against time.
Any specific pattern indicates the possible
source of the problem, which can be
considered for rectification.
Since, data are taken only for a small time
of paper manufactured, sometimes, it may
be required to repeat the same.
60. Single Position MD Profiling
Cutter
12 11 10 9
8
7
5
6 5
4
3 ….
Unwind
# A 2 minute profile can be used to reveal much information.
# For a longer duration, 10th or 20th alternate samples can
also be used.
61. Another Typical Single
Position MD Profile:
140.0
Possibily due to testing error.
135.0
Stable
130.0
Stable
Stable
125.0
120.0
1
18
35
52 69
86 103 120 137 154 171 188
62. Issues:
Different zones of relatively stable gsm
Single Position MD Profile
140.0
Possibily due to testing error.
135.0
130.0
Stable
Stable
Stable
125.0
1
16
31
46
61
76
91
106
121
136
151
166
181
196
120.0
• These zones exist for a small time duration of
say 30-50 seconds.
• Had the operator taken sample 30-50
seconds earlier or later, what gsm value he
would have observed?
• For a two minute MD plot (gsm range 122132 in the plot), to achieve 120 gsm, should
the operator reduce gsm by 2 or by 12?
Fluctuations within stable zones
• 127 to 132 gsm in first stable zone.
• What should the operator do when he checks
that the sample is of 127 gsm or 132 gsm?
Why does it happen?
63. A Typical Approach Flow:
Often, the conventional approach flow
system looks perfect, as below…
64. Seems a perfect system!
Ideally, if inlet consistency is fixed,
basis weight should remain fixed.
But, if the consistency is changing at
different points, basis weight
fluctuation cannot be controlled.
But, the inlet consistency to head box
keeps on changing.
65. Inlet Consistency Changes!
How?
Yes, it keeps on changing due to
various reasons e.g.
Pump speed variations due to voltage,
frequency etc.
Presence of entrained air through
pump glands etc.
Centricleaner pit level and consistency
variations
As a result, profile gets disturbed.
66. Effects:
In most of such cases DCS & QCS systems
malfunction as scanners do not seem to
sense correct basis weight.
Single Position MD Profile
140.0
Possibily due to testing error.
135.0
130.0
Stable
Stable
Stable
125.0
1
16
31
46
61
76
91
106
121
136
151
166
181
196
120.0
67. Reasons:
Fan Pump Pulsations:
RPM: 1500, vanes: 6, Speed: 200mpm
Pulse to pulse difference: 200/(1500*6)
i.e. 0.02 m
So, for such a case, on lower speeds, fan pump
pulsation can’t harm you; but if the speed itself
is fluctuating….?
Similarly, effect of other equipments e.g
pressure screen, holey rolls etc. can be
considered.
At higher machine speeds fan pump pulsations
create significant problems.
68. Typical Inferences:
A bend/misaligned holey roll
Entrained air in approach flow
systems
Inadequate inlet pressure at pressure
screen inlet
Centricleaner pit level and
consistency fluctuations
69. Typical Actions Taken:
Installation of a new closed
centricleaner
Installation of VFDs for all approach
flow pumps
Provision of air venting lines at
different piping locations
Correct alignment of holey roll.
70. Typical Results:
For a yankee machine(No consistency regulator, no DCS)Average basis weight for 24 hours varied
between 48.2-49.4gsm; Individual samples
between 47.4-50.2gsm
Average basis weight for 72 hours varied
between 54.7-57.0gsm; Individual samples
between 54.0-57.8gsm
Reduction in CD profile variation by more
than 50% after such studies were made and
suitable actions were taken.
71. Extra Benefits:
For a yankee machine(No consistency regulator, no DCS)Machine joints reduced to just 25-30% of
earlier
Increase in machine speed by 3-5%
72. How to begin?
If you are not satisfied with the basis
weight control you are having, just
follow the following steps-
73. Single Position MD Profile
Collect data on single position in machine
direction at drive end, non-drive end and at
centre.
Ensure that the data are being taken from
such a roll of paper that no process change
had been done prior to at least 10 minutes
before producing that roll. Also, the basis
weight control should be running in manual
control mode.
74. Plot a Graph
Make a graph plotting time at ‘X’ axis,
and basis weight at ‘Y’ axis. Such
study is known as Time Series
Analysis in mathematics.
Identify any repeated pattern. If hills
and valleys are repeated, compute
their frequency.
75. Analyze
Now, look at the equipment in the
machine the frequency of which
matches with the plot. This is going to
be your first enemy. Do the needful to
minimize the problem it is creating.
76. Correct
Take corrective action to solve the
problem identified. Once the problem
is solved the variations from such
section are reduced.
77. Repeat:
Having rectified the problem of earlier
identified culprit, repeat single position
MD profiling, and quite possibly you
may find another culprit.
Very soon, you would be observing a
better basis weight control.
78. Finally….
You will be getting better basis weight
control.
Please do not forget to share your experiences
with others. I’d really like to have your email
containing your achievements in my inbox.
79. Average GSM as a Function
of Time (after modification)
37
36.5
36
35.5
35
34.5
34
1
5
9 13 17 21 25 29 33 37 41 45
45.4
45.3
45.2
45.1
45
44.9
44.8
44.7
44.6
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