Waveguides for long-distance energy transport in microwave heating

ABSTRACT

Performance of waveguides for long-distance energy transport in microwave heating was evaluated by comparing the microwave propagation characteristics, including maximum transmitted power P_trans, attenuation constant α and percentage of power loss p_loss proposed in this study, of commercially available rectangular waveguides (WRs) constructed of various metals (Ag, Cu, Ag, Al and Fe) for microwave heating at 0.915 and 2.45 GHz with those of different types of circular waveguides, namely circular waveguides with the same cut-off frequency as rectangular waveguides (denoted by WCFs), circular waveguides with the size equal to rectangular waveguide (denoted by WCDs), and circular waveguides with the same circumference as rectangular waveguides (denoted by WCCs). It is demonstrated that WCFs exhibit the highest values of maximum P_trans together with lowest α and p_loss due to their characteristics of microwave field configuration. Circular waveguides (e.g. WCF1150) made of Cu or Al with large dimensions operating at 0.915 GHz are suitable for microwave heating through long-distance microwave energy transport over the distance compared to traditional rectangular waveguides, with up to ∼50% reduction of power loss. Optimal waveguides for long-distance uses can be obtained by assessing microwave propagation characteristics together with manufacturing cost, depending on specific applications.

KEYWORDS:

• Microwave heating
• long-distance energy transport
• waveguide
• transmitted power
• attenuation constant
• power loss
• cut-off frequency

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number 51504297]; Shenghua Lieying Program of Central South University [grant number 502035001]; Innovation-Driven Program of Central South University [grant number 2016CXS021]; Science and Technology Major Project of Gansu Province, China [grant number 1602FKDC007]; Fundamental Research Funds for the Central Universities of Central South University [grant number 2016zzts464].

Notes on contributors

Zhiwei Peng

Zhiwei Peng was born in Changsha, Hunan, China, in 1983. He received the BE degree in mineral processing engineering and the MS degree in ferrous metallurgy from Central South University, Changsha, Hunan, China, in 2005 and 2008, respectively, and the PhD degree in materials science and engineering from Michigan Technological University, Houghton, MI, USA, in 2012. He is currently an associate professor with the School of Minerals Processing and Bioengineering, Central South University. His research interests include theory and application of microwave heating, electromagnetic compatibility, resources recycling, and synthesis of functional materials.

Xiaolong Lin

Xiaolong Lin was born in Jingzhou, Hubei, China, in 1992. He received the BE degree in mineral processing engineering from Wuhan Institute of Technology in 2015. He is currently a masterstudent in the School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan, China. His research interests include use of microwave energy in pyrometallurgy, waste management, and materials synthesis.

Jiann-Yang Hwang

Jiann-Yang Hwang was born in Taipei, Taiwan, in 1952. He received the BS degree in earth sciences from National Cheng Kung University, Tainan, Taiwan, in 1974, the MS degree in geosciences-mineralogy and economic geology and the PhD degree in multidisciplinary program from Purdue University, Lafayette, IN, USA, in 1980 and 1982, respectively. He is currently a professor with the Department of Materials Science and Engineering, Michigan Technological University, Houghton, MI, USA. His research interests include microwaves, separation technologies, pyrometallurgy, hydrogen storages, ceramics, recycling, water treatment, environmental protection, biomaterials, and energy and fuels.

Matthew Andriese

Matthew Andriese was born in Lansing, MI, USA, in 1984. He received the BS and MS degrees in materials science and engineering from Michigan Technological University, Houghton, MI, USA, in 2008 and 2012, respectively, where he is currently pursuing the PhD degree in materials science and engineering. His research interests include mineral processing, extractive metallurgy, and microwave heating.

Yuanbo Zhang

Yuanbo Zhang was born in Dawu, Hubei, China, in 1976. He received the BE degree in mineral processing engineering and the PhD degree inferrous metallurgy from Central South University, Changsha, Hunan, China, in 2000 and 2006, respectively. He is currently a professor with the School of Minerals Processing and Bioengineering, Central South University. His research interests include resource conservation, agglomeration, pyrometallurgy, and environmental protection.

Guanghui Li

Guanghui Li was born in Yiyang, Hunan, China, in 1972. He received the BE and MS degrees in minerals engineering from Central South University of Technology (now Central South University), Changsha, Hunan, China, in 1996 and 1999, respectively, and the PhD degree in minerals engineering from Central South University in 2002. He is currently a professor with the School of Minerals Processing and Bioengineering, Central South University. His research interests include mineral processing, agglomeration, process metallurgy, and pollution control and prevention.

Tao Jiang

Tao Jiang was born in Suixi, Anhui, China, in 1963. He received the BE degree in nonferrous metallurgy from Central South Institute of Mining and Metallurgy (now Central South University), Changsha, Hunan, China, in 1983, the MS and PhD degrees in minerals engineering from Central South University of Technology (now Central South University) in 1986 and 1990, respectively. He is currently thedean of the School of Minerals Processing and Bioengineering, Central South University. His research interests include agglomeration, extractive metallurgy, and mineral processing.