Dr Aaron Huber has been closely associated with the North American glass industry for the past three decades, working for two of the industry’s leading players. A passion for research has featured throughout, with his early years at the Ford Motor Co’s Glass Division, followed by an ongoing 20 year career at the glass fibre producer Johns Manville.
As Senior Manager for Glass Melting at Johns Manville, he is responsible for technology innovation, furnace design, conducting furnace post mortems and the CFD modelling of processes. This includes monitoring and forecasting furnace campaign life, thereby affording adequate time to prepare for rebuilds. Historical knowledge gained from furnace campaign post mortems and production histories, along with CFD modelling tools, are employed to develop the best design for a location and business need.
Premium insulation specialist
Johns Manville is a Berkshire Hathaway company and leading supplier of premium quality products for building insulation, mechanical insulation, commercial roofing and roof insulation, as well as fibres and non-wovens for commercial, industrial and residential applications. E-glass, C-glass and several specialty glass compositions are produced.
Target markets include aerospace, automotive and transportation, air handling, appliance, HVAC, pipe and equipment, filtration, waterproofing, building, flooring, interiors and wind energy. In business since 1858, the Denver-based company has annual sales of more than $3 billion and holds leadership positions in all key markets served.
Forty two manufacturing facilities are operated in North America, Europe and China, more than a third of which are glass fibre manufacturing plants. According to Aaron Huber, every glass melting process is designed to meet or exceed business needs and regulatory requirements and depending on product and location, designs vary to meet specific objectives.
Passion for research
Aaron Huber’s father had been a professor at Purdue University and in his youth, Aaron enjoyed assisting with research projects and building customised equipment for agriculture research plots. This passion for research and building led him to pursue a degree in mechanical engineering. Although planning to attend Purdue University for a master’s degree focusing on composite materials, he was offered the opportunity to complete a master’s degree project at the USA National Science Foundation sponsored Advanced Combustion Engineering Research Center, located at Brigham Young University. Accepting the combustion research project provided exposure to computational fluid dynamics (CFD) and the thermal sciences, while designing and constructing a pilot reactor to conduct experiments.
Following this experience, his focus of attention switched from composite materials to heat and mass transfer and in 1993, earned a doctoral degree in mechanical engineering from Purdue University with Dr Raymond Viskanta. Dr Viskanta was one of the early developers of glass furnace modelling.
Aaron Huber’s main doctoral work was in the area of heat and mass transfer, with a focus on impingement heat transfer. To provide financial support in graduate school, in 1989 he also started working on glass manufacturing projects. This included spectral remote sensing of the temperature distribution in flat glass (infrared temperature sensors) and the tempering of glass, while also participating in reviews of CFD modelling work for the Ford Motor Co’s Glass Division. And on completion of his doctoral degree, this led to a position as a Technical Specialist in the Glass Division at Ford Motor Co.
At Ford, Aaron Huber worked on process design and development, the development and implementation of infrared sensors for process control and optimisation, advanced controls and computer modelling (CFD). “Ford Motor Co and my manager at the Glass Division encouraged publications and participation in conferences” he recalls, a philosophy that provided valuable exposure to the glass industry. “When the US Department of Energy decided to target the top energy-intensive industries with workshops and research funding, I was able to participate in the glass industry meetings.”
In 1995, he was invited to draft the USDoE Glass Technology Roadmap for the flat glass sector, which was subsequently combined with the other glass segments into the 1996 published roadmap Glass: A Clear Vision for a Bright Future. This work was the precursor to the formation of the Glass Manufacturing Industry Council (GMIC).
It was in 1999 that Ford Motor Co decided to close/sell off its Glass Division facilities. Via one of the glass industry contacts made through the USDoE-sponsored workshops (Foster Harding, Senior Scientist at Johns Manville), a technical position was offered at the Littleton Colorado Technical Center. Aaron Huber has been working at Johns Manville ever since.
His initial focus was on developing computer modelling capabilities and implementing advanced control for glass manufacturing processes in the Advanced Manufacturing group. This group evolved into the Process Research and Development group and then into the present-day Process Technology group. “I serve as Senior Manager for Glass Melting and have responsibility for new technology, furnace design and the CFD modelling of glass melting processes.”
According to Aaron Huber, seeing the results from developing and implementing infrared temperature scanners for advanced control on float and tempering lines was one of several highlights realised at Ford Glass. And implementing advanced supervisory controls and measuring the production improvements from 1999 to 2004
at Johns Manville was another.
“In addition, the opportunity to use CFD modelling as a tool to evaluate new furnace designs and potential improvements, implement and then measure the very large impact over the past 20 years of furnace operation at Johns Manville has been very rewarding.
“The opportunity to interact with other glass industry professionals has also been a highlight. Those contacts have delivered opportunities to hold technical exchanges with many different glass companies to expand our knowledge base beyond Johns Manville” Dr Huber adds.
“Being involved with the creation and operation of the GMIC over the past 25 years is another achievement. I continue to serve on the GMIC board of directors and served terms as Vice President in 2005 and President in 2006, besides leading the search committee from 2008 to 2010 to hire the current GMIC Executive Director, Robert Lipetz in October 2010.”
In addition, Aaron Huber has served as a member of the International Commission on Glass (ICG) TC15 (sensors and controls) and TC21 (modelling of glass furnaces) technical committees since his time at Ford Motor Co and currently serves as Chairman of the recently combined TC21 and TC15 committee, ‘Furnace Design and Operation’. He has published more than 25 papers, holds more than 25 patents and has written over 100 corporate archival reports. And in 2017, he was awarded the 7th GS Modelling Award for noteworthy contribution to the glass industry in the field of mathematical modelling.
Innovative technologies explored
The Johns Manville Glass Melting Group strives constantly to produce high quality materials that add value for its customers. This involves addressing furnace campaign life along with production and energy efficiency, while dealing with such constraints as space (footprint) or downstream limitations. Innovative technologies or designs are explored to continually improve with trials and CFD modelling.
CFD modelling is recognised as an important tool to evaluate the latest technologies and designs, as well as trouble shooting operational issues. It is used for a variety of applications including design and operational support of glass furnaces, glass forming and collection processes, as well as fibre glass mat production.
“Trials with burners or batch materials can be conducted but for many important factors, trials are impossible” says Aaron Huber. “Thus, CFD modelling is the most effective tool to evaluate the impact of a furnace design change, such as bubbler or electrode locations or furnace geometry. While it still takes expertise to use the tool properly, the use of CFD modelling has significantly improved glass production during the past quarter of a century.”
Carbon footprint reduction emphasis
The first complete glass furnace conversion to oxygen firing conducted by Johns Manville took place in 1989 and was rapidly implemented on other melters. In 1997, the company’s first oxygen/natural gas-fired forehearth was also commissioned.
In addition to combustion-fired melters, many all-electric furnaces are also operated by Johns Manville, continuous improvements having led to significant carbon footprint reductions over the past two decades. In May 2019, Aaron Huber presented a paper at the 15th International Seminar on Furnace Design, Operation and Process Simulation that provided a general overview of the impact of technology options on CO2 emissions. He believes there are several existing technology options that can enable the CO2 reductions required to achieve the 2030 EU requirements and development options to reach the 2050 EU requirements.
In the area of traditional glass melting technologies, Dr Huber hopes to see constant improvement in terms of campaign life, throughput, energy, emissions and cost over the next 20 years. “However, an obstacle for major breakthrough technologies is the lack of funding and support for development” he warns. “Most companies are reluctant to spend funds now for something that will not have a payback in less than two years. This limits possible large technology advances. But the 2030 and 2050 EU regulations on greenhouse gas emission reductions will be an additional driver for larger and more rapid technology improvements. Increased electric boost and reduced combustion input (whether hydrogen or natural gas) will be the trend.”
Building industry relationships
Aaron Huber recognises the benefits to his team and company of maintaining a close involvement with such organisations as GMIC and ICG, which provide valuable opportunities to develop relationships with others in the glass industry and expand the view beyond that of a single company.
“GMIC, for example, supports the industry by promoting the use of glass, representing the industry and providing opportunities for information exchange and interaction” he says. “GMIC membership is beneficial due to the opportunity to interact with other members of the glass industry, to obtain information and help direct promotion and improvement efforts. Hosting workshops, supporting the annual Conference on Glass Problems, disseminating information and exploring development opportunities are all valuable activities.” Furthermore, a broader approach to the GMIC’s strategic thinking is delivered via the involvement of technology suppliers, as well as glassmakers on its board of officers and trustees.
Among the organisation’s many successful innovations has been its preparation and publication of the Glass Manufacturing Industry Report, which provides important information to understand the industry and evaluate individual status. The GMIC also jointly organises the annual Conference on Glass Problems (GPC) together with Alfred University. “The GPC allows many from the North American glass industry the opportunity to see what is occurring globally and expand viewpoints” Dr Huber contends. “Without the GPC, there would be a large void for many of the technical people who are unable to attend global conferences outside North America and see what is occurring with other companies, while interacting with suppliers and observing available technologies and developments.”
Delivering furnace improvements
Similarly, Aaron Huber is a longstanding supporter of the International Commission on Glass and an advocate of its technical committees. “The ICG provides the global framework to exchange knowledge” he emphasises.
As mentioned earlier, Dr Huber has been Chairman of TC21 (Furnace Design and Operation) since 2016, its overriding objective being to promote improved glass furnace design and operation with sophisticated tools such as computer modelling, advanced sensors and intelligent controls. This is achieved by hosting conference sessions and meetings that allow for presentations and discussions about innovative furnace and control concepts to improve energy efficiency and increase glass quality, as well as technical approaches.
Round robin tests (RRTs) represent another valuable tool and currently, TC21 is conducting RRT number 6 phase 1, computer modeling of a small cold top electric melter. This initiative allows committee members to model and discuss issues, while accurately predicting the performance of this selected simplified glass furnace. Following the initial work, possible design and operation improvements will be discussed and evaluated.
Aaron Huber’s personal, long-term commitment to advancing the research and development of glass melting technology matches the aspirations of like-minded individuals within such organisations as GMIC and ICG, while delivering critical improvements on behalf of Johns Manville. “The more glass industry manufacturers, suppliers and researchers participate, the better the glass industry will be able to address future challenges and continue to improve” he concludes.