On the preparation of energy balances for brick and tile-making plants (Part 1)

»1 Beam balance [1] in the balance state, with both sides carrying the same weight

»2 Tunnel kiln with a charge of standing roof tiles and an indicated balance envelope

»3 True specific heat capacities of solids and gases as functions of temperature [2-4]

»4 Sankey diagram for the energy balance of a dryer used in the production of backing bricks (with the specific heat flows expressed in kJ/kg, specific to evaporated water)

»5 Sankey diagram for the energy balance of a kiln used in the production of backing bricks (with the specific heat flows expressed in kJ/kg, specific to fired heavy clay products)

This tripartite article describes the basic theory and practice of preparing energy and mass balances for dryers and kilns in the brick and tile industry. The criteria to be met by the requisite test instruments are described, as are the available software solutions for use in generating energy balances. Special attention is devoted to methods applied for checking the plausibility of such balances. Parts 2 and 3 will appear in the next upcoming issues of Zi Brick and Tile Industry International.

1 Introduction

The energy consumption of a given facility is always of interest and, when energy resources are limited or expensive, often the objective of intensive investigation. The efficiency of dryers and kilns is evaluated on the basis of energy balances. Energy balances enable statements concerning:

› energy conservation potentials

› comparison of the energy efficiency of different operating conditions

› the technical and financial assessment of newbuild projects (insulation of dryer walls, refractory superstructures for kiln cars)

Similar to double-entry bookkeeping, the...

Issue 11/2012

On the preparation of energy balances for brick and tile-making plants (Part 1)

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On the preparation of energy balances for brick and tile-making plants (Part 3)

Combined kiln-dryer heating systems with thermochemical heat storage

On the preparation of energy balances for brick and tile-making plants (Part 2)

Optimizing the energy efficiency of a tunnel kiln by decoupling the kiln/dryer heat cycle

Combined heat and power generation in the brick and tile industry – savings potentials through innovative dryer heating

ZI 09/2012