Stefan Falkner, Karl Ponweiser

Modelling, simulation and validation of brick drying in a laboratory chamber dryer

This article describes the development of an open, easily expandable drying library for use in investigating the drying behaviour of clay bricks in a chamber dryer. The proposed modelling approaches and resultant mathematical formulations were implemented in the modelling language Modelica and validated as a specific application on the basis of measured data from drying tests performed in a laboratory container. All key properties and processes were reproduced with sufficient accuracy. Multi-domain simulations, such as optimization tasks in connection with plant management or performance studies, are easily accomplished by combining elements of the drying library with other user-defined or standard libraries.

1 Introduction

Convective drying is a very energy intensive process, because the latent evaporation enthalpy required for removing the entire moisture content must be supplied. Also, convective dryers exhibit notoriously low efficiency, often below 50% [1].

However, the use of dryers is on the increase, due not least to the market appearance of numerous new drying-relevant appurtenances. In 2016, the industry accounted for approx. 30% of Austria’s end-use energy consumption. It counts among the main sources of climate-relevant emissions, since only 50%  of the overall industrial energy...

Related articles:

Issue 8/2015

Use of heat pumps in brick drying

For a brickworks with a production rate of 400 tonnes per day fired ware, the mixing water content of around 20 mass% necessary for pressing means that every day around 80 t water must be expelled...

Issue 11/2012

Waste heat utilization and integrated energy supply in brick and tile factories

When, as a result of increasing energy prices, the costs incurred for the energy-intensive process steps of drying and firing rise, measures for energy saving and the economically efficient use of...

Issue 11/2013

Utilizing recovered air in the chamber dryer – possibilities and limitations

Compared to continuous dryers, chamber dryers have the energy drawback that the drying air supplied is not fully saturated when it is discharged from the process. Already very early on, dryer designs...

Issue 8/2016

Hybrid dryer

TCKI has developed a new drying process for chamber dryers (hybrid dryers) that can reduce the specific annual energy consumption for drying from approx. 4?000 to roughly 3?000?kJ/?kg water. It...

Issue 6/2017

Effective dryer control based on material-specific moisture content – Part 1: Material data

Drying green products is easily the most energy-intensive process step in clay brick and tile production. For the purpose of process control, it is interesting to know the distribution of moisture in...