Abo Bibliothek: Guest

ISSN Online: 2377-424X

ISBN CD: 1-56700-226-9

ISBN Online: 1-56700-225-0

International Heat Transfer Conference 13
August, 13-18, 2006, Sydney, Australia

ANALYSIS OF THE PERFORMANCE OF A TUNNEL KILN USING NATURAL GAS

Get access (open in a dialog) DOI: 10.1615/IHTC13.p13.80
11 pages

Abstrakt

In this work, the flow and heat transfer of combustion gases inside a tunnel kiln are investigated numerically. This furnace, used for red ceramic fabrication, is a counter-flow kiln, and consists of three distinct zones: pre-heating, firing and cooling zones. The load enters the furnace at the preheating zone. Heat is transferred to the load from the combustion gases flowing counter-currently to the ware and coming from the firing zone. In the cooling zone, the product is cooled and exits the furnace. Usually, sawdust is used as a fuel in the tunnel kilns. However, the use of natural gas is becoming very attractive, because it may decrease the cost of energy consumption and reduces the pollutants emission. Therefore, natural gas is used in this work to evaluate its performance as fuel. The numerical solution was obtained by using a bi-dimensional simplified approach, solving the governing conservation equations via the finite volume method and using the Fluent software, with a non-uniform structured mesh. Due to high temperature levels, radiation heat transfer was considered, and the Discrete Transfer Radiation Model was used. The velocity, pressure and temperature fields inside the furnace were obtained and analyzed. A good agreement with experimental results was obtained, indicating that natural gas can be employed as fuel. The effects of permeability and load porosity on temperature fields were investigated and were considered negligible. The effects of inlet combustion gases temperature, and inlet excess air from the furnaces were also studied, and it was observed that they strongly affect the temperature field inside the kiln.