MAERZ OFENBAU AG

The Maerz hybrid kiln for variable
lime reactivity

All Maerz

1 Rectangular Maerz PFR kiln for high reactive lime (left) and Maerz HPS kiln for medium and low reactive lime (right)

2 SEM analyses of lime samples burnt at 1050, 1450 and 1850°C (from left to right)

3 Cross-section through a Maerz hybrid kiln

4 Gas temperature and calcination curve in the Maerz hybrid kiln

5 Adjustable lime reactivity

6 CFD-DEM simulation of the degree of calcination in the Maerz hybrid kiln

7 Gas temperature in the crossover channel of the Maerz hybrid kiln

8 Comparison of heat consumption and CO₂emissions

At the International Lime Association’s General Assembly and Information Exchange Forum in October 2019 in Buenos Aires/Argentina, Maerz Ofenbau AG introduced a new kiln type permitting the production of lime with variable reactivity by combining the thermal efficiency of the parallel flow regenerative process with the features of a counterflow kiln.

1 Introduction

The development of modern lime kilns to date has been focusing on the optimisation of the specific heat consumption as well as on the flexibility to use a wide variety of fuels. Little attention was paid to the flexibility of producing lime with variable reactivity. Hence, the kilns were either optimised to produce high reactive lime with the Parallel Flow Regenerative (PFR) lime kiln, originally invented by Maerz Ofenbau AG, as being one of the most commonly built kiln types throughout the world, or to produce medium or low reactive lime, with mainly single shaft kilns based on...