MARCHELUZZO: Drying of Heavy Clay Ceramics
The term drying means removing most of the water present inside the brick by controlling the temperature and humidity of the drying environment. This phase has a variable duration that depends mainly on the procent of water present in the mixture and on the size of the pieces. There are several types of drying systems but all of them base their operating principle on the relationship that is created between the amount of air introduced into the drying environment and the thermal energy it contains. The drying processes, over the years, have undergone an evolution given above all by the ability to be able to dry, in the shortest possible time, large quantities of materials, often at the expense of an optimal treatment of the material.
In the research and development offices of MARCHELUZZO S.p.A./IT the drying theme has always been and continues to be an aspect of the process where the characteristics of the raw materials, the quality of the final product and above all the energy aspect share a single goal, to be able to make available of its customers all the most suitable technology for the treatment of their products. Over the last few years, the various types of bricks, such as masonry blocks and roofing tiles, have undergone dimensional and geometric changes that often do not find positive feedback on traditional systems originally designed for materials other than the current ones. MARCHELUZZO S.p.A. in this sense, tried to develop the right skills internally to be able to give the most appropriate answers to an evolving market that is trying, despite the difficulties, to give greater efficiency and modernity of operation within its own realities.
The best-known dryers are undoubtedly the semi-continuous and static chambers. These machines have always based their operation on the management, more or less correct, of variable quantities of hot air introduced into the tunnels and subsequent internal ventilation designed to pass the hot air through the material placed on the appropriate supports. The combination of these activities through a correct scientific approach has shown the possibility of being able to optimize the amount of air used but above all of being able to convey it through the material in a more appropriate way, ensuring greater efficiency and less stress for the products.
In recent years, MARCHELUZZO S.p.A. has promoted new projects by addressing innovations on the internal ventilation system that have allowed a significant reduction in cycles and also a reduction in the energy used, see perforated wall ventilation, pass-through ventilation type DT and cone ventilation. The DT dryers are the result of an approach to the drying process that takes into account the creation of the right operating conditions for each trolley through optimal management of lateral flow ventilation of the air speed and energy introduced into that area. No less important is the management of the recovery air arriving from the tunnel kilns, the last one can be introduced inside the tunnels dryers without however creating a counter-current flow that would unbalance the transverse flows given by the thrust of the tunnels by special ventilating machines. Through modern equipment and systems for checking the behaviour of the brick in the drying phase, it is possible to understand in a visualized way the behaviour of the air on the material, the contribution of energy and then evaluate the effective homogeneous heating capacity of the piece.