Energy efficiency considerations in the Indian foundry industry

The iron foundry industry in India comprises of units that are largely under the small scale sector. The foundry units are typically located in clusters, with the cluster size varying from 100 units to around 400 units. This paper details the findings of the energy efficiency study carried out for the foundry cluster located at Agra, Uttar Pradesh. A cluster approach was followed in the study, as there are certain commonalities in different units within a cluster like technology level, operating practices, product type, trade practices, etc. which makes the outcome of the study more useful in terms of wider applicability. There are 200 registered small scale foundry units in the cluster. The metal melting furnace (cupola) employed by the industry suffers from gross inefficiency. The coke feed rate of the furnaces (amount of coke required to melt one tonne of iron-an index of furnace efficiency) varies from 1:3 to 1:5, which is much higher than the achievable figure. Energy audits were undertaken in representative units in the cluster with a view to assess the energy use efficiency of these units. Detailed mass and energy balance of the furnaces were carried out to identify areas of energy wastages and possible energy saving options applicable for the melting furnaces. Based on the energy audits, a set of energy conservation measures were identified with a high rate of return and fairly attractive payback periods. It was concluded that by improving the furnace operating practices and by simple cost effective retrofit measures, it is possible to bring down the coke consumption in the furnaces by 25-35%.