Natural Gas Intermittent Kiln for the Ceramic Industry: A Transient Thermal Analysis

Ricardo S Gomez,Antonio G B Lima,Hortência L F Magalhães,Anastácia M M C N André,Túlio R N Porto,Gicelia Moreira,Ruth B F Melo

doi:10.3390/en12081568

Ricardo S Gomez, Antonio G B Lima + Show 5 more

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https://doi.org/10.3390/en12081568

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Abstract

Drying and firing of ceramic products are processes that require high energy consumption. Making these processes more efficient can improve product quality, reduce processing time and energy consumption, and promote economic and environmental gains. In this sense, this work aims to quantify heat transfer in an intermittent ceramic kiln during the heating and cooling stages, with and without thermal insulation. All mathematical formulation is based on the first law of thermodynamics. From the results, we conclude that the greatest heat loss occurs by radiation in the sidewalls of the equipment, and that a considerable amount of energy is required to heat the sidewalls, base, and ceiling of the kiln. Further, with the use of thermal insulation, it was concluded that a high reduction in the heat lost through the sidewalls was achieved, thus providing a global energy gain of approximately 35% and a reduction in the maximum external surface temperature from 249.34 to 79.47 °C when compared to the kiln without thermal insulation, reducing the risks of work accidents and thermal discomfort when in operation.

Highlights

Ceramic or ceramic material comprises all inorganic, non-metallic materials, generally obtained after heat treatment at elevated temperatures [1]
The wet part must be submitted to the drying stage, which consists of a thermodynamic process of heat transfer and moisture removal in the porous materials [1]
It is important that the ceramic parts are submitted to a suitable drying process to give them the necessary strength and consistency during the firing stage [8]

Summary

Introduction

Ceramic or ceramic material comprises all inorganic, non-metallic materials, generally obtained after heat treatment at elevated temperatures [1]. According to Brongniart [2], clay is the most widespread raw material on the Earth's surface, and is molded, it has various practical and artistic applications. These characteristics justify the fact that ceramics have appeared in different civilizations, at different periods and on all regions of the world, since the end of the Paleolithic period [3,4]. The wet part must be submitted to the drying stage, which consists of a thermodynamic process of heat transfer and moisture removal in the porous materials [1]. It is important that the ceramic parts are submitted to a suitable drying process to give them the necessary strength and consistency during the firing stage [8]

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