KilnCon 2023
TAPPI Virginia-Carolina, Gulf Coast and Southeastern Local Sections Present
KILNCON 2023
The Preeminent Event: Gathering experience and skill combined into workshops, technical sessions and social opportunities for anyone and everyone involved with Lime Kilns & Recaust
Thursday, December 14 and Friday, December 15, 2023
Great Wolf Lodge, Williamsburg, VA
Meeting Officers
Meeting and Session Chairman: Glenn Hanson, Metso – 717-578-9610
Local Arrangements: John DeJarnette, WestRock – 540-717-6214
Schedule of Events
Thursday, December 14
8:00am – 1:30pm Check-in and registration
8:00am – 5:00pm Technical Program/Workshop Sessions (Grand Oak Ballroom)
Part One
9:00am – Noon
Lime Kiln & Recaust – Process and Operations
“Turnin’ Burnin’ & Churnin’ – From Mud to Reburn & Green to White”
8:00am – 10:00am – Lime Kiln Process/Operations Workshop
Facilitator: Glenn Hanson, USA Pyro Technical Sales Support, Metso
Preliminary Description:
- The Lime Kiln Process
- Types of Kilns
- Combustion & Heat Transfer in the Lime Kiln
- Improving Lime Kiln Efficiency (Basic Optimization and Major Projects)
- Lime Kiln Quality Considerations and Related Process Concerns
- General Guidelines for Lime Kiln Operation
10:00am – 10:15am – Break
10:15am – Noon – Recaust Process/Operations Workshop
Facilitator: Jeff Butler, Mills Division—Center of Excellence, Manager Engineering Services, Graphic Packaging International
Preliminary Description: Any experienced chef will tell you the best quality ingredients and tools are necessary to make recipes work. To make good white liquor and have the least problems in recausticizing, it is essential to have clean green liquor, high quality reburned lime and good causticizing control. This presentation covers these topics and relates the importance of each step and the equipment involved in the recausticizing process. Included will be functional descriptions, current sizing standards and troubleshooting problems in recausticizing operations.
Noon – 1:00pm – Lunch (provided by your TAPPI Local Section Hosts)
Part Two
1:00m – 5:00pm
Lime Kiln Maintenance “As the Kiln Turns and Keeps Turning”
1:00pm – 2:15pm – Kiln Maintenance Workshop
Facilitator: Glen Cahala, Sales Engineer, A-C Equipment Services
Preliminary Description:
- Basic Lime Kiln Mechanical Design
- Kiln Shell, Tires/Riding Rings, Carrying/Support/Trunnion Rollers, Bearings, Thrust Mechanisms
- General Lime Kiln Inspections: Daily, Monthly Annually
- Ovality: What is It and Why is It Critical to Monitor
- Lime Kiln Drive Systems
- Open Discussion/Q&A on Lime Kiln Maintenance
2:15pm – 2:30pm – Break
2:30pm – 3:00pm – Kiln Alignment Workshop
Facilitator: Thom Zhang, PhD, PE, Principal Engineer, Optimus Solutions
Hot Kiln Alignments are a vital and critical set of services designed to analyze current kiln axis arrangement as well as other measurements that can offer insight into needed adjustments, repairs and/or parts replacement on rotary kilns. This presentation will cover the basics of hot kiln alignment surveys, different ways they are performed, and the additional measurements that can be taken to guide getting kilns into optimum mechanical operating condition.
3:00pm – 3:15pm – Break
3:15pm – 3:45pm – Kiln Alignment Workshop (cont)
Facilitator: Justin Bready (tentative), Project Manager, Kiln Technology Inc.
What should be expected in a Hot Kiln Alignment and what should you do with the information that you receive?
Facilitator: Andy Knouse, Field Service Alignment Specialist, Metso
How process and mechanical conditions affect lime recovery kiln thrust positions – a review of operations and mechanics for this phenomenon.
3:45pm – 4:00pm – Break
4:00pm – 4:45pm – Kiln Alignment Panel Discussion and Open Q&A
All four of the afternoon presenters will be available for the Q&A discussion.
5:00pm – 5:30pm – Local Section Planning Meeting
WE NEED VOLUNTEERS! Come help RESTART and ENERGIZE the Virginia-Carolina Local Section. Find out how this section operates, help plan the future, and find out where you might plug in! This is an open meeting and EVERYONE is welcome to attend.
6:00pm – 8:00pm – Social Reception
Oak Pre-Function Area, Great Wolf Lodge
All registered attendees are welcome! Come and enjoy snacks and refreshments and unwind with your fellow KilnConics.
Schedule of Events
Friday, December 15
8:00am – 1:30pm Check-in and Registration
8:00am – 5:00pm Technical Program/Workshop Sessions (Grand Oak Ballroom)
8:00am – 9:30am TECHNICAL SESSION 1
Rotary Kiln Support Systems: A Comprehensive Examination of the Rotational Support System for Rotary Kilns
Facilitator: Andrew Wisner, Director of Operations, NAK Kiln Services
Rotary Kiln Support Systems: A Comprehensive examination of the rotational support system for rotary kilns.
High Efficiency Cyclone System – A Mill Case Study
Presenter: Todd Lewick, Project Manager, Andritz
This mill case study describes a project where a high efficiency cyclone system was installed on a kiln. It is a follow up to a paper presented at a TAPPI PEERS Conference where the theoretical basis was presented for increasing kiln efficiency and capacity by installation of a properly designed high efficiency cyclone system to encourage kiln internal dust recycle. Mill operating data and operational experience is presented showing “real world” benefits obtained when a properly designed cyclone system is installed.
“Lime Kiln Dynamics; How to Increase Capacity and/or Efficiency”
Presenter: Tobin Alt, Vice President, Chemical Pulping Group, Kadant Black Clawson
9:30am – 9:45am – Break
9:45am – Noon TECHNICAL SESSION 2
Facilitator: Brooks Epting, Assistant Recovery Superintendent, WestRock
Pokin’, Chokin’, Shootin’ & Shutdowns – A Working Mill Solution
Presenter: Glenn Hanson, Pyro Technical Sales Support, Metso
This presentation reviews common causes, contributing factors and resolutions to kiln build-up. Often kiln internal buildup must be removed as it limits production and/or the excessive loading affects the kiln mechanical operation. A mill with chronic issues looked at similar areas and overall area processes to find root contributors and develop solutions. Presentation includes updates on their work which has continued to the point of near total elimination of kiln build-up issues and the associated operational problems and costs. Additional current issues facing the lime kiln/recaust area of the mill will also be presented and discussed.
Proactive Ring Removal at Resolute Forest Products (now New Indy Containerboard), Catawba, South Carolina Mill: A Case Study
Presenter (Tentative): Jim Conover, Director of Business Development, IA Bulk Materials
Ring formation occurs in the rotary kilns used by the pulp and paper industry to regenerate the lime. The presence of rings can restrict the movement of material through the kiln. Even if the root cause of ring formation is known, from a practical standpoint, it can be difficult to eliminate rings. In mills where ring formation is a recurring problem, mechanical ring removal systems should be considered. This presentation will present a current successful case study on the use of a CO2 system for ring mitigation.
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Reducing Downtime and Event Frequency of Lime Kiln I.D. Fan Scaling & Cleaning Through Fan Operation Evaluation and Upgrade with Increased Efficiency I.D. Fan Rotor Design
Presenter: Andrew Webster, Technical Sales, AirStream Systems Inc.
The heavy dust load passing through the I.D. fan represents a major problem for mills, as the dust sticks to the fan blades. Over time, this build-up accumulates and eventually a piece breaks off putting the rotor out of balance. Operators are forced to shut down the lime kiln to clean the fan. We’ve successfully solved severe build-up problems in many lime kiln applications with our high-efficiency rotor upgrade approach. In addition to solving build-up, these projects have been able to provide significant power savings. This presentation will review several actual case studies on lime kilns demonstrating the problems solved & benefits seen from I.D. fan retrofits.
Mill Study on Increasing Lime Kiln Efficiency
Presenter: John DeJarnette, Senior R&D Researcher, WestRock Corporation
Optimization of the lime kiln requires a review of the entire lime cycle. To increase the energy efficiency of the kiln, all auxiliary unit operations must function properly. It is also imperative that the lime and liquor in the system is of acceptable quality. We detail a kiln energy efficiency study performed at the WestRock Covington, VA mill. From a recausticizing standpoint, lime quality is much easier to control than liquor quality because liquor passes through many operations that are not under the lime kiln operator’s control. Recausticizing is a fairly closed cyclical process where lime is concerned, so saturation of impurities to the point of operational issues must be considered. To get a true picture of the cost of operating the lime cycle, all inputs must be considered. The four main inputs are power, (electrical and fuel), fresh lime, caustic and water. Process engineers can use this detailed troubleshooting approach to help optimize various parts of a mill.
Noon – 1:00pm – Lunch (provided by your TAPPI Local Section Hosts)
1:00pm – 2:30pm TECHNICAL SESSION 3
Modern Lime Kiln Burner Designs to Better Control Thermal Profile When Firing Natural Gas
Presenter: Martin Beddows, Product Manager, Burners Metso KFS Product Line
Many mills have switched from fuel oils and/or solid fuels to natural gas due to the dramatic decrease in pricing in recent years. Unfortunately, natural gas burns differently and with not as much radiant intensity resulting in reduced product quality control, decreased kiln production and exit gas volume and temperature constraints. Several burner companies have developed design modifications and changes to allow thermal profiles more similar to liquid fuels when firing natural gas. Additional benefits of these designs include NOx control and, in a mill case, reduced cooler plugging. This presentation will offer before and after mill lime kiln operational data showing the benefits and value of these new designs.
Alternative Fuel Firing to Reduce Carbon Emissions in Lime Kilns
Presenter: (Tentative)
Pressure across all industries around the world to reduce their carbon footprint through the use of alternative fuels. This presentation will review the various fuels in use and with potential to be used in the future to reduce carbon emissions from often the largest fossil fuel consumer in a kraft pulp mill.
Issues, Experience and Hope for the Future; Lime Kiln Operating Experiences with NCG Firing
Presenter: Jeff Butler, Mills Division-Center of Excellence, Manager Engineering Services, Graphic Packaging International
The Graphic Packaging Mill at West Monroe, Louisiana has had some negative issues occurring when firing NCGs. Some of these have been addressed, including burner adjustments and initial trials on operational changes such as operating with firing hood doors closed, which show positive promise. Following the initial presentation, we would look to facilitate a discussion on overall mill experiences to help us all find ways to improve operations and avoid costly production impairment and/or downtime.
2:30pm – 2:45pm – Break
2:45pm – 3:30pm TECHNICAL SESSION 4
Design and Performance of Chain Systems in Rotary Kilns Used to Regenerate Lime in the Pulp and Paper Industry
Presenter: Peter Gorog, Principle, Houghton Cascade Holdings, LLC
As with any heat exchanger, it is the heat transfer surface area that is the most important aspect of chain system design. Increasing the chain surface area always lowers the heat rate while at the same time increasing the gas temperature at the hot end of the chain section. In the end, it is a combination of the area, chain density and economics that determine the amount of chain that can be effectively hung in the kiln. This presentation will discuss how the fuel type, mud moisture, excess air, shell heat losses, and other operating parameters impact the optimum design of the chain system for a given kiln.
Optimizing the Water Balance – Recausticizing Area
Presenter: Tobin Alt, Vice President, Chemical Pulping Group, Kadant Black Clawson
Optimizing water balance throughout the kraft process is critical to avoid chemical losses and maximize washing. This presentation will cover common issues and concepts to optimize water usage to produce Lime Mud with the least chemical content.
3:30pm – 3:45pm – Break
3:45pm – 5:00pm TECHNICAL SESSION 5
Selection of Lime Kiln Refractories to Balance Cost and Efficiency
Presenter: Chris Macey, Market Manager, Resco Products
Kilns used to regenerate lime in the Kraft process are highly energy intensive. Due to the dramatic decline in the price of natural gas over the last decade, in combination with mounting pressures to increase production of existing assets, many mills are currently focusing more on increasing uptime and capacity as opposed to energy savings. This presentation provides recommendations to aid mill personnel in the design of optimized refractory linings for specific situations.
Refractory Brick Installation Guidelines for Increased Kiln Reliability
Presenter: Ryan McDonald, Application Specialist, Harbison-Walker International
The refractory brick lining in a lime recovery kiln is a critical element to overall kiln reliability and uptime. Refractory life is influenced by installation practices, kiln design and condition, refractory technology, and other operational factors. This presentation provides kiln owners and operators best practices to monitor installations, identify abnormal wear mechanisms, and troubleshoot potential refractory brick problems.
New and Improved Lime Kiln Refractory for Energy and Emissions Savings
Presenter: Kevin Regan, Director – New Mkt Development/Sr. Tech Sales Manager, Refratechnik
Refractory manufacturers have developed new lines of reduced thermal conductivity “ES” rotary kiln brick – which have a dual meaning of energy savings (lower kiln shell temps) as well as potential emissions savings (via reduced fuel consumption). Typical products include 60% High Alumina (Andalusite) brick which is the primary refractory quality used in lime kilns.