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

In this paper, the firing of ceramic ware in tunnel kilns is analysed with the help of a mathematical process model. As an example, the firing of horizontally stacked roof tiles is simulated. In addition to the energy balance, the influence of design, operating and setting parameters on the firing curve is shown. Based on these results, concepts for the further development of the tunnel kiln process are presented in a second part entitled “Simulation of the firing of ceramic ware – Part 2: Roadmap for CO2-free production by 2050”.

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 average about 2 300 kJ per kg of fired ware [1]. This energy is usually supplied to the process in the form of natural gas. In relation to this, the evaporation of the initial water content (mixing water) determines the theoretical minimum energy demand (»1).

If the average water content is assumed to be 20 % by mass, the minimum energy demand for drying is 625 kJ per kg of fired ware. The sintering...

Related articles:

Issue 4/2020 Dr.-Ing. Tino Redemann, Prof. Dr.-Ing. Eckehard Specht

Simulation of the firing of ceramic ware Part 2: Roadmap for CO2-free brick production by 2050

1 Introduction Firing bricks in the tunnel kiln is a high-temperature process and therefore energy-intensive. The energy costs make up a significant part of the production costs. It is to be expected...

more
Issue 7/2015 Keller AG Ziegeleien, Paradies brickworks, Schlatt, Switzerland; Peter Krieg1, David Hartmann2

Optimizing kiln run quality with tailored flue gas flow

1 Introduction In brick production, the firing curve is determined in part by the type of raw material employed. This has been the subject of numerous investigations, the facts of which are surely...

more
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...

more
Issue 6/2020 Eckard Rimpel, Anne Giese, Tim Nowakowski, Tim Schneider, Markus Martl, Christian Siefke, Florian Scherer, Tobias Bem

Improving energy efficiency with the use of hot cooling air in a new combustion concept

1 Starting situation and background In the clay brick and tile industry, modern tunnel kilns achieve the process control necessary to handle high capacities and obtain consistent product qualities...

more
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...

more