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Title On the Dominant Factors of the Heat Transfer Phenomena in Industrial Furnaces
Creator Miwa, Masataka; Aoki, Shuichi; Nakamura, Yasuhisa
Publisher Digitized by J. Willard Marriott Library, University of Utah
Date 1998
Spatial Coverage presented at Maui, Hawaii
Abstract The aim of this investigation is to find dominant factors in unsteady heat transfer phenomena during transient heating process in two types of industrial furnace though experiments and numerical simulations. Experiments were carried out using a directly gas-fired batch furnace with a circulating fan whose maximum temperarute was 773 K and heat input was 27 kW, and a indirectly fired furnace with radiant tubes of 1173 K and 26 kW. In the case of the transient heating process of the directly gas-fired furnace, an increase in the circulating rate of the atmosphere promotes uniformity in the atmospheric temperature in the furnace, but causes a drop in the efficiency of the furnace. This is because an increase in the heat transfer rate on the thermal insulating wall surface promotes heat losses through the furnace walls. In the case of the indirectly gas-fired furnace, because the convective heat transfer rate is rather low and the radiative heat transfer plays a major role in the energy transfer in the furnace, the temperature dependencies of the physical properties of the insulating material work as major factord domaining the heat transfer in the furnace. Numerical simulations using a commercial CFD code FLUENT/UNS were also carried out on indirectly gas-fired furnece adopting the dominant factors revealed from the experiments.
Type Text
Format application/pdf
Language eng
Rights This material may be protected by copyright. Permission required for use in any form. For further information please contact the American Flame Research Committee.
Conversion Specifications Original scanned with Canon EOS-1Ds Mark II, 16.7 megapixel digital camera and saved as 400 ppi uncompressed TIFF, 16 bit depth.
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ARK ark:/87278/s6ft8pm6
Setname uu_afrc
ID 11433
Reference URL https://collections.lib.utah.edu/ark:/87278/s6ft8pm6

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Title Page 10
Format application/pdf
OCR Text Table 1 Masses of furnace elements (directly gas-fired furnace) Furnace element muffle inner wall (SUS310) circulating fan thermal insulator* Mass (kg) 14.5 41.1 11.2 142.0 Furnace element roller outer wall (S45C) fan axis Work Mass (kg) 13.4 68.7 1.84 0.98 *:This value indicats sum of masses of Rock Wool and Ceramic Wool. Table 3 Work Reynolds number (directly gas-fired furnace) Fan speed r.p.m. 906 1086 1260 1480 Atmos. temp. (K) 288 423 573 673 773 288 423 573 673 773 288 423 573 673 773 288 423 573 673 773 Pressure diff. *l AP (Pa) 184.84 126.46 93.05 79.14 68.71 265.79 181.66 133.68 113.66 98.66 357.31 244.73 178.98 152.84 132.99 460.36 314.95 231.81 196.99 171.68 Work Reynolds num. Re*2 4237 3240 2567 2331 2096 4995 3889 3086 2785 2513 5794 4512 3574 3240 2930 6579 5114 4061 3680 3320 *1, This value indicats pressure difference produced by the circulating fan. *2, Re = Ul/v, U: area avelage velocity, I: length scale of the work (0.05m), v. kinematic viscosity of atmosphere.
Setname uu_afrc
ID 11426
Reference URL https://collections.lib.utah.edu/ark:/87278/s6ft8pm6/11426