Secret Losses in Dedusting Systems - Optimisation of Ducts & Routing Pays Off!
Secret Losses in Dedusting Systems - Optimisation of Ducts & Routing Pays Off! BY VOLKER KNOTH *1 CARSTEN PFUNDSTEIN *2 SYNOPSIS: Reduction of energy consumption is an actual task for all industries in general, and for energy consumption intensive steel plants in particular. The melting process through the EAF route con-sumes high amounts of electrical energy but also other resources such as natural gas, coke, etc. Heavy efforts were done in the past and are on their way today to reduce the consumption of en-ergy, both by applying new technologies and increasing of efficiency of existing operational in-stallations. The focus here was laid on the EAF itself and maybe the ladle furnaces. Reductions of 10 – 20 kWh/t were celebrated but achieved by significant investments on the equipment side. The target was mainly reduction of operational costs. Today one focus is still on operational costs, but sometimes availability of electrical energy, re-duction of the “carbon foot print” of a product or other environmental aspects have become even more important. Few steel plants were aware of the fact, that there are other significant consum-ers of energy which were not in the limelight of interest, although they contribute significantly to total energy consumption and consequently to operational costs of a steel plant. One of the major energy consumers of an EAF operation is the dedusting system. The specific consumption of energy at the dedusting system for steel production can reach from as low as 20 kWh/t up to as high as 80 kWh/t. In many cases the dedusting system is either much older than the furnace equipment and/or in a bad shape and/or not optimised in terms of efficiency. BSE has been developing tools and strategies to investigate, address and identify weak points of a dedusting system in terms of efficiency and energy consumption. Furthermore, BSE designs and implements optimisation measures to improve the efficiency of a system. Three possible routes can be taken: increase of flow rate at the same energy consumption level OR reduction of energy consumption at the same flow rate OR a combination of both. The choice depends on the individual situation and requirements of the steel plant. Out of the grand total of details and sources of losses this presentation covers aspects of duct de-sign and duct routing layout as an example for optimisation potential in dedusting systems. Cost savings of up to 50 % and efficiency increase of more than 100 % are feasible respectively were achieved. 2011 ESCO Seminar