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

Decoupling the kiln/dryer heat cycle by means of an upstream or downstream kiln tunnel is an inexpensive way to optimize the energy efficiency of a clay products plant. This not only improves its energy balance in general, but also maximizes its energy efficiency. Decoupling makes it possible to optimally employ the energy resources in accordance with their respective qualities while achieving maximum overall efficiency. With presently or soon to be available technology, energy expenditures can be reduced by as much as approx. 35 % within a relatively short time.

Medium-term savings of 50 % or more appear feasible. By way of a concrete example, and based on actual energy audits, this paper presents ways and means of dissolving an existing kiln/dryer heat cycle and describes how reducing the kiln‘s exhaust temperature can save substantial amounts of energy and attendant costs. Moreover, future perspectives are offered on the design of brickyards with essentially emission-neutral production capabilities.

Prof. Dr.-Ing. Christian Schäffer, Hochschule Koblenz,

Werkstofftechnik Glas und Keramik


Related articles:

Issue 2012-11

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 2014-08

Alternative waste heat recovery

Around the world, some 50% of all process energy is expelled unused as waste heat. It is therefore extremely important that ways be found to make better use of such off-heat from production processes....

Issue 2015-8

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 2018-6

New concept for improving heat transfer in tunnel kilns

Ceramic products have to be fired before they can be used, and tunnel kilns are well-suited for the job. To help optimize a kiln‘s energy efficiency, fans can be installed in the preheating and...

Issue 2018-6

Using funding opportunities with the help of the new KfW energy efficiency scheme “Waste Heat Utilization”

The utilization of waste heat has been established in the clay brick and tile industry for many years, it is common for the waste heat from the kiln to be used to dry green products. This involves...