Conference Presentations – Ceramics, Metals, Powders

Modeling Heat Transfer and Reaction Energy of Tungsten Carburization in a Pusher Furnace
PowderMet – 2018
The production of tungsten carbide in a pusher style carburization furnace is known to proceed via an exothermic reaction between the tungsten metal and carbon powders.  That reaction has a significant impact on the time-temperature history experienced by the powder mixture.  An exothermic reaction was indeed observed during recent experimental studies of the temperature distribution in an industrial scale quantity of mix-milled powder. The exothermic reaction initiated at a temperature where it could progress rapidly throughout the bed.  The reaction onset initiation temperature decreased with powder size.  An FEA simulation was performed to estimate the effect of the exothermic reaction. Since the software did not have the capability for modeling chemical reactions, the reaction energy was applied as ‘body heat’ beginning at the reaction initiation temperature. The model was validated for the batch mode test and then extended to real carburization configurations. This presentation outlines the model and the data obtained. Download Now.

Microwave Technology for Processing of Metals
Powdermet – 2017
It is generally accepted that microwave energy can provide volumetric heating and therefore be used for energy efficient, rapid thermochemical processing. It is also widely believed that microwave equipment is not suitable for processing metals. However, proper design of equipment, taking into account the material properties, their form factor, and changes in properties during thermal processing, can enable advantageous utilization of microwave energy. Proper equipment design can help regulate the energy input and ensure that it is delivered in the appropriate locations. This presentation discusses ideas for equipment and process design heating applications including, processing of hard metals and other similar materials, indirect heating of metals with microwaves, and production of metal powders from precursors. Download Now.

Modeling Heat Transfer in a W+C Powder Bed in a Pusher Furnace
Plansee Seminar – 2017
Written in conjunction with Global Tungsten & Powders for a presentation at the Plansee Seminar, this paper discusses the nature of the WC produced in pusher furnaces and how it is influenced by numerous variables. A model was created to assist in the design of W carburization furnaces with the objective of obtaining uniform heating of the powder bed, and was applied to real carburization furnace configurations. Download Paper Now.

Plenary Session Panel: Forecasting Key Ceramic Markets to Understand Industry Trends
Ceramics Expo – 2017
With the global advanced ceramic market estimated by some research reports to reach $134.58 billion by 2024, discussion of the drivers and limitations in scale up for thermal processing is critical for success. Harper sat on a panel at the third edition of the annual Conference @ Ceramics Expo providing an update on the status and forecast of key ceramic markets driving this growth, such as ceramic matrix composites, ceramic coatings, and other ceramics applications. Download Now.

Holistic Design of Thermochemical Processing for Ceramic Production
Ceramics Expo – 2016
In order to be able to manufacture the advanced ceramic and glass containing products that fulfill the numerous applications in the telecommunication, transportation, medical, and energy industries, equipment is needed that can withstand the extremely high temperatures that are demanded during the production of these items. This presentation covers innovation in process equipment and technology and how it is helping the ceramics manufacturing industry to lower costs, increase productivity and assure quality. Download Now.

Moving from Batch to Continuous Production – Challenges and Risk Mitigation for High Temperature Ceramics Processing
Ceramics Expo – 2015
This technical presentation discusses the design of high temperature thermal processes from batch to continuous scale in ceramics production, focused on reduced operating costs and increased productivity. Topics include managing risk and common stumbling blocks, material flowability, bed depth, off-gassing, retention times, and cross contamination, including case studies and technical examples. Download Now.

Analysis of the Heating of Proppants in a Pusher Furnace
MS&T – 2014
When processing powders in Pusher furnaces, understanding of heating profile and product temperature uniformity is imperative. In many cases, thermal properties of the materials are not well known as a function of temperature. This information is required for product uniformity analysis. This presentation presents results of time – temperature – uniformity predictions for different geometries and particle sizes. Download Now.

Modeling Very High Temperature, Dense Cloud, Free-Fall Heating for Particles with Wide Particle Size Distributions
MS&T – October 2013
This technical presentation discusses a modeling tool to properly size vertical free-fall reactors for the desired target production rate. The model considers heavy particles (acceleration), semi-opaque clouds (efficiency vs. efficacy), collisions between particles in different size (or shape) families (in case sticking is anticipated), and temperature dependent properties of the gases and solids (to account for phase changes). Download Paper Now. Download Presentation Now.

 

Conference Presentations – Carbon Fiber

Manufacturing of Carbon Fiber from Pitch
Carbon Fiber NOW 2021
The continued demand for low weight carbon fiber composites in automotive and aerospace applications is continuing to drive the carbon fiber industry towards developing good quality low cost carbon fiber to compete with traditional metal alloys such as aluminum. The majority of carbon fiber currently produced uses polyacrylonitrile (PAN) and other co-monomers as the precursor. One major disadvantage of using PAN precursors is the OPEX is high due to the energy intensive reaction kinetics of the precursor during the stabilization processing step. Combine this with the fact that the carbon fiber yield using PAN is 50% or less and standard PAN based precursors and processing are not advantageous to producing a low cost carbon fiber. Download Now.

Distinguishing Features of a Carbonization Line Designed for Heavy Tows
GOCarbonFibre – 2017
A number of applications for heavy tows are forecasting to have growth in demand,  including ground and marine transportation, wind energy, and infrastructure. Expanded heavy tow capacity and lowering costs will be critical factors in achieving the more optimistic forecasts. This technical presentation discusses a thermal model of light and heavy tows in an Oxidation Oven, and highlights how the difference between light and heavy tows guides the equipment design and operation. Download Now.

Progressive Production Techniques for Industrial Carbon Fiber
JEC World (Paris) – 2017
Manufacturers face the challenge to continuously advance state-of-the-art Carbon Fiber processing to support market advancement. This technical presentation discusses 3 progressive techniques to address this challenge, including utilizing high performance computer modeling, microwave heating, and advanced on-line measurement systems in Carbon Fiber production systems. Download Now.

How Will Carbon Fiber Manufacturing Quadruple to Meet Market Demands?
Composites World Carbon Fiber – 2016
The Carbon Fiber industry must begin considering now how 10,000 ton per year lines for PAN precursor can be achieved to ensure increased capacity for projected future automotive demand at a lower cost. This presentation will demonstrate some of the possible plant configurations for key variables such as towband width, filament count, thermal residence times and operability. The risks associated with making such a massive jump from today’s 2,500 ton per year lines are also examined in this analysis. Download Now.

The Future of High Capacity Carbon Fiber Production
JEC World (Paris) – 2016
Carbon fiber applications for ground transportation exert market pressure towards increased capacity and lower cost. Today large capacity carbonization lines for PAN precursor are in the range of 1500 – 2500 tons per year. Much larger lines promise both investment and operating cost advantages due to the economies of scale. They also reduce the number of new lines and associated lead time required for adding large amounts of capacity. This presentation focuses on 10,000 ton per year lines for PAN precursor, analyzing feasibility, opportunities and risks. Download Now.

Global Expansion in Carbon Fiber Manufacturing: Strategic Considerations for Energy Utilization
CompositesWorld Carbon Fiber – 2015
The emergence of low cost natural gas in various parts of the world has spurred deeper discussion around energy utilization for Carbon Fiber thermal conversion, being a highly energy-sensitive process. This presentation considers the importance of planning for the right energy source in the design of manufacturing plants in various regions, addressing implications on the cost of producing Carbon Fiber and design of thermal processing equipment. Download Now.

Novel Oxidation Oven Technology for the Next Generation of Carbon Fiber Manufacturing
GOCarbonFibre – 2015
This presentation discusses how insights from advanced Oven CFD modeling can guide designs offering improvements to efficiency and safety, how utilities for Ovens, as the highest energy consumer in the manufacturing process, can be optimized for flexibility and performance, and how modular designs can offer improvements to typically long lead time installations. Download Now.

Thermo, Chemical, Process Model of Non-Textile Reinforcing Fiber
SAMPE – 2015
One of the formats used for making advanced reinforcing fibers including non-PAN based carbon fiber has the precursor as a non-woven mat. Harper’s model can be used to analyze the heating of nonwoven mats of arbitrary reinforcing fiber precursor (generally polymeric) fibers, using radiation, convection, gas-phase conduction and process thermodynamics to predict the thermal and chemical profiles over time. Examples are discussed showing the use of the model to provide commercially interesting results, such as allowable bed depths, relationship between parameters and process time (equipment size / capacity). Download Now.

Carbon Fiber Manufacturing – Designing Research Systems for Scale Up
Carbon Fiber & Composites Workshop – 2015
Success in commercial production begins with thoughtful decisions made during the design of the research and piloting scale carbon fiber process systems. This methodology helps ensure research program goals are considered along with the need to output relevant data and minimize the number of future process and design tweaks. Download Now.

Maximizing the Competitive Benefits of Low Cost Natural Gas in the Manufacturing of Carbon Fiber
JEC Europe – 2015
Current energy trends shifting towards increased natural gas utilization can result in performance and economic advantages under certain conditions when considered in the design of a Carbon Fiber manufacturing plant. This presentation will discuss innovations to allow for a shift to gas-fired units and hybrid gas / electric designs with improved control and thermal uniformity, as well as a focus on reduction of utilities consumed in the thermal conversion process. Download Now.

Enabling Optimization and Growth of Carbon Fiber Production Through Computational Fluid Dynamics (CFD) Modeling Analysis
JEC Europe – March 2014
Carbon Fiber producers are challenged to balance product quality, economics, and safety as the industry grows rapidly due to increased demand. All three of these areas are critical to a stable and sustainable supply of product to meet the expanding requirements of end use markets. To help support this, Harper’s presentation at JEC Europe reported the results of Computational Fluid Dynamics (CFD) modeling to simulate the operation of ovens, LT, and HT furnaces in a Carbon Fiber production line. The results reveal important aspects that Carbon Fiber producers must consider in the physical dimensions, operating techniques, and design features of their production line that are highly impactful to product quality, economics, and safety. Download Now.

How Mass Automotive Use Will Affect the Carbon Footprint of Carbon Fiber Production Facilities
GOCarbon Fibre – October 2013
As carbon fiber production rates grow to accommodate demand from expanded aerospace usage and new automotive applications, safety and environmental considerations must become a more strategic element of capacity expansion plans in order to mitigate scale up risk and meet demanding schedules.  Harper International’s carbon fiber expert Dr. Bill Stry presented on several critical safety and environmental factors in this context, in order to assist the industry with knowledge that will benefit its’ continued growth. Download Now.

Critical Oxidation Oven Designs to Enable Research System Goals
Carbon Fiber R&D Workshop – July 2013
Harper discusses the various generations of Oxidation Ovens that can help research programs accelerate and achieve program goals, designed from the inside out to meet objectives of speed in lieu capacity/output, precision in data retrieval, efficiency in usage of minimal precursor to garner maximum results, and flexibility in handling multiple precursor formats. Download Now.

Industry Trends in High Modulus Fiber and UHT Technology
Carbon Fiber R&D Workshop – July 2013
This presentation discusses the chemistry and innate challenges of high modulus fiber, leading into the unique thermal technology used to produce this fiber. UHT systems which are required to operate at temperatures up to 3000° necessitate inventive designs for the materials of construction, sealing technology, and atmosphere control. Download Now.

Key Parameters for Consideration in the Development of a Carbon Fiber Research Line
SAMPE – May 2013
In this paper, Harper reviews process technology advancements in research scale systems to enable flexibility, control and management of the development of alternative carbon fiber precursors. We also cover key design considerations and technology solutions to facilitate most innovative areas of carbon fiber research today, such as fractional tow sizes, carbon nanotube containing carbon fibers, lignin, polyethylene and more. Download Now.

Processing Advancements Within Reach for Achieving Significant Reductions in Carbon Fiber Cost of Manufacturing
JEC Europe – March 2013
Harper discusses a different approach to rethinking carbon fiber production unit operations to support reduced environmental losses, reduced purge barriers and reconfiguration to meet achievable targets for future growth. Download Now.

 

Conference Presentations – Nuclear

Thermal Process Technology for Nuclear Application-20379
Waste Management Symposium – March 2020
ANSTO’s Synroc technology has been developed to provide a safe, secure matrix for the immobilization and final disposal of radioactive wasted. Synroc technology will be used to manage radioactive wastes from the production of the radioisotope Molybdenum-99 (Mo-99). This paper shall outline various stages of the process development with the specific reference to the thermal treatment technology of calcination. Calcination is a key step in the Synroc process [1-2]. The rotary thermal processing system includes: an advanced heating element design for increased robustness and ease of remote operation and maintenance, an enhanced modular design of components for ease of remote maintenance in a hot cell and in compliance with hot cell radioactive environment requirements for safety, reliability and maintainability. Download Now.