Christophe Aubertot

Why use radically new kiln concepts – and how?

For quite a few years now, the US American company Direxa Engineering, LLC and its business partner in research and development, the French company Ceritherm, have been working on radically new ideas for continuous kilns for the ceramics industry. This article documents the status of their progress.

1 Introduction

In the ceramics industry, a tunnel kiln can be simply defined as a continuous furnace where products to be fired and the heating/cooling air travel in opposite directions, as schematized in »1.

Given the fact that 1 kg of air and 1 kg of clay/shale have about the same specific heat (0.24 and 0.22 kcal/kg/C respectively), one could conclude that a perfect tunnel kiln is where about 1 kg of air travelling one way will suffice to heat and cool 1 kg of product travelling in counter flow to the air.

In reality, this ratio in tunnel kilns varies from 2 to 4.5 kg/air per kg of fired...

Related articles:

Issue 09/2009

The role of the combined heat system in the brick plant

1 Introduction The combined heat system between the kiln and dryer was already used in individual cases at the beginning of the 20th century in large-volume dryers arranged above the annular kiln...

Issue 11/2009

New energy-saving tunnel kiln for Grasten Teglvaerk A/S

1 Introduction The Grasten Teglvaerk brickyard is owned by a venerable old Danish brick-making family who, for 8 generations now, have been producing some 30 varieties of high-quality facing bricks in...

Issue 05/2012

Firing technology for energy-rich raw materials

1 Project definition The sought-after characteristics of porous backing bricks, such as low body density and high heat insulation, are achieved for instance with the addition of porosity-enhancing...

Issue 1/2020 M.Sc. Tino Redemann, Prof. Dr.-Ing. Eckehard Specht

Simulation of the firing of ceramic ware Part 1: Understanding the firing process in tunnel kilns

1 Introduction The production of building ceramics such as clay pavers, facing and hollow bricks and roof tiles is an energy-intensive process. Drying and firing in industrial practice require on...

Issue 7/2015

Concept of a new low-energy tunnel kiln for energy saving and production efficiency

Direxa Engineering, LLC, an engineering company based in Colorado, USA, and specializing in heat treatment for various industries, and its R&D projects partners Ceritherm and Seipia, both French...