Temperature uniformity evaluation of a shuttle kiln for the sanitary ware industry using CFD

Abstract

Shuttle kilns are widely used in the sanitary ware industry. A key parameter to reduce energy consumption and increase their overall performance is temperature uniformity. Therefore, in this paper a systematic and statistical study of the effect of the position of burners and their interactions on the temperature uniformity of a shuttle kiln is performed. CFD simulations and a 4k factorial analysis were used to determine, quantitatively and qualitatively, the best burner configuration in hterms of kiln temperature uniformity. It was found that the proximity of the burners has a negative impact on the temperature distribution of the kiln. These proximities caused collisions of the burners streams which deflected the flow in the Y-axis direction. This may increase the outlet velocity of the combustion gases, diminishing the heat exchange between gases and the ceramic pieces, producing a heterogeneous distribution of temperature. The standard deviation varied from 2.29 to 3.78 depending of the configuration of the burners used. To avoid these negative effects, collisions between the streams of the burners should be avoided. Also, the distance between the furniture carts of the kiln could be varied to maximise the heat exchange inside. The results obtained are useful in the design of ceramic shuttle kilns, as it allows one to determine the quantitative and qualitative effect of the position of the burners at different sections of the kiln.

Keywords:

• Kiln temperature uniformity
• computational fluid dynamics
• burner configuration
• ceramic industry
• statistical analysis

Acknowledgements

The support provided by the Instituto Tecnológico de Estudios Superiores de Monterrey and Nutec Bickley for the development of this investigation is acknowledged and greatly appreciated. This research did not receive any specific grants from funding agencies in the public, commercial, or not-for-profit sectors.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Nomenclature

Ci	=	Coefficient i of the regression equation
Ci contribution %	=	Contribution of the term i, of the regression equation, to the SD of the kiln temperature
$C_{\mu }$	=	Turbulence model constant
$d_h$	=	Hydraulic diameter (m)
h	=	Convective heat transfer coefficient (W m−2 K−1)
k	=	Turbulent kinetic energy (m2 s−2)
l	=	Turbulent length scale (m)
$\overline{q}$	=	Convective heat flux (W m−2)
SD	=	Standard deviation
t	=	Time (s)
T	=	Temperature (K)
Tavg	=	Average temperature (K)
V	=	Velocity (m s−1)
Y	=	Calculated SD through the correlation equation

Greek symbols

ε

=

Viscous dissipation rate of turbulent kinetic energy (m2 s−3)

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This research is a product of Project 266632 ‘Laboratorio Binacional para la Gestión Inteligente de la Sustentabilidad Energética y la Formación Tecnológica’ [‘Bi-National Laboratory on Smart Sustainable Energy Management and Technology Training’], funded by the Consejo Nacional de Ciencia y Tecnología (Agreement: S0019-2014-01).