Cement and Energy

A lathiyur plant of Madras Cements Ltd is among.the five best energy-efficient high tension (liT) industrial units of Tamil Nadu, adjudged in an Energy Efficiency competition jointly organised by the Confederation of Indian Industry - Southern Region (CII– SR) and the Tamil Nadu Electricity Board (TNEB). The award consisting of a Certificate of Merit along with Shield!frophy was presented at the conclusion of a unique one-day Seminar on Energy Conservation organised in Chennai on 2 September 1999. The winners for the award were selected from among the IS top energy efficient liT industrial units of Tamil Nadu, on the basis of their successful case studies, presented at the Seminar. These units in turn had earlier been selected by a Panel of Judges based on an initial questionnaire survey. The award scheme is part of the energy efficiency promotion drive launched by CII and TNEB among liT consumers of Tamil Nadu whose sanctioned demand exceeds 2000 KVA. ENERGY OPTIMISED CONVEYOR BELTS C ontiTech Transportbandsysteme, a German firm, has developed belts that in the installed state, use up to I0 per cent less energy and at the same time conserve natural resources. Laboratory tests even suggest savings of up to 30 per cent in the energy needed to move belts that naturally sag. The secret, according to ContiTech, is in the compound and fabric design and in the resistance offered by the belts. For conveyor lengths of ·more than 500 m, the rolling resistance overcoming the sag makes up 50-60 per cent of the total resistance to movement . Investigations show that different compounds for the bottom cover, the thickness of the cover, as well as the type and arrangement of the reinforcing materials, all play a crucial role in this. By varying these features, the resistance can be reduced by up to 40 per cent. Using the finite element method ContiTech calculate how a belt gets deformed at idlers. When doing this, the properties of the belt cover and design are taken into account. As expected, the main energy losses.occur in the belt layer that comes into contact with the idlers, but the overall belt design and the reinforcing plies have a significant influence. Courtesy: International Cement Review, July 1999 Results of this test were checked by the Independent Institute for Materials Handling Technology at the University of Hannover. The researchers compared the energy required to move sagging belts of the same design, but that had covers of different thicknesses. In different tests, ContiTech experts optimised the compound and the belts design. In the end they arrived at a theoretical reduction of approximately 35 per cent, compared to the basic tried and tested type - and that had itself been previously rated as good. measurements confirmed the calculations Practical for two experimental belts (ST2500 10+8T) with optimised cover, the rolling resistance of the sagging belt was about 35 per cent lower. The benefits of energy-optimised conveyor belts include a lower power requirement and a belt that does not need to be so strong. In practice, belts with a lower strength rating will give the same reliability- a more cost-effective overall solution. 10