Carry-over of raw material reactions in the preheating zone for energy utilization of carbon-containing body constituents

For firing high-thermal-insulation clay blocks, the raw materials must meet certain preconditions and the firing process fulfil certain requirements. These are necessary to make more efficient use of the raw materials enthalpy contained in the clay blocks owing to the addition of pore-forming agents. Associated with this is the release of combustion heat to save on the energy supplied by burners. It is significant how and how far the exothermal and endothermal reactions can be influenced based on design of the firing process and the atmospheric conditions to maximize efficiency for realization of the raw material enthalpy. In the process for firing bricks, facing bricks and roofing tiles, the carbon contained in the raw material is generally regarded as a nuisance. Its burn-off and associated formation of reduction cores often present a firing problem. One energy advantage of the raw material enthalpy requires that the formation of the body structure during the preheating process and the gas diffusion required for the expiration of reaction gases follow certain laws.

Dipl.-Ing. Michael Ruppik, Brick and Tile Research Institute Essen Regd.

x

Related articles:

Issue 2016-8

Influence of the atmosphere on the tunnel kiln process

In the making of clay bricks, the firing process is particularly important. It crucially influences the product quality as well as the costs of the overall process. To ensure a uniform transfer of...

more
Technical Paper

Causes and avoidance of damage on account of diffusion-dependent reactions in the preheating zone of tunnel kilns

1 Introduction The firing of heavy clay products is subject to a number of such limiting factors as expansion and contraction processes, endothermic and exothermic reactions and the conversion and...

more
Issue 2015-8

Raw material analyses and body development for innovative­ clay brick and tile products

In the talk, the development of a body for a clay roofing tile is described by way of example – from testing of the individual raw materials through selection of the suitable batch components to the...

more
Issue 2017-1

Unipor: New generation of “Unipor Silvacor” clay blocks

With the new generation of “Unipor Silvacor” clay blocks, the Unipor Group is presenting a sustainable building material solution that also improves living comfort. Like the Coriso clay block, the...

more

Unipor: New generation of “Unipor Silvacor” clay blocks

With the new generation of “Unipor Silvacor” clay blocks, the Unipor Group is presenting a sustainable building material solution that also improves living comfort. Like the Coriso clay block, the...

more