Enhancing productivity
Enhancing productivity

Enhancing productivity

Use of synthetic bearing lubricant helps increase oil drain interval by more than 2.5 times, thereby resulting in savings of over $27,677/kiln.

India is the second largest producer of cement in the world after China. However due to unfavourable demand-supply scenario, the industry is reeling under the pressure of rising input costs. Today, manufacturers are under tremendous pressure due to reducing profit margins and increased competition.

To combat the continual increase in input costs, and minimise production cost, we need to optimise operations. Cement plants are 'hot beds' for equipment problems, as they continuously perform under harsh conditions. A typical process of manufacture consists of three stages:
  • Grinding a mixture of limestone and clay or shale to make a fine "rawmix"
  • Heating the rawmix to temperature up to 1,450°C in a cement kiln
  • Grinding the resulting clinker to make cement

    In the second stage, the rawmix is fed into the kiln and gradually heated by contact with the hot gases from combustion of the kiln fuel. Successive chemical reactions take place as the temperature of the rawmix rises. The objective of kiln operation is to make clinker at the maximum rate that the size of kiln will allow, while meeting environmental standards at the lowest possible operating cost. This creates challenges, which in turn necessitates a careful selection of lubricants as an integral part of the modern processing techniques in cement plants.

    High operating temperatures
    Rajashree Cement (RC), a unit of Grasim Industries Ltd, is an ISO 14001 certified company, and one of the largest cement manufacturing units in India with a gross clinker production capacity of 4.0 MTPA. Catering to the residential and commercial segment of the construction industry, the company manufactures white and grey cement, and operates a opencast mine using state-of-the-art technology and was the winner of the National Award for 'Quality Excellence In Indian Cement Industry' by National Council For Cement and Building Materials, for the year 2000-01. At its facility, Rajashree Cement employs three production lines with integrated cement lines and individual kilns of 166 TPH capacity. The support rollers here were typically lubricated by a mineral oil of ISO VG 460 with the bearings running at very high temperatures (78-85°C). Such high temperatures led to frequent tripping of motors. Due to contamination and oxidation that usually occurs at high temperatures, the lube oils required annual replacement. This combination of factors affected the productivity of the plant.

    Faced with the recurring problem of tripping of motors, which in turn affected productivity, the company approached the Field Engineers at Mobil™¢ Industrial Lubricants, who had worked closely with other leading cement producers, to seek expert advice on best-in-class lubrication and maintenance practices for operating kilns.

    Typically, a seamless and uninterrupted operation of the kiln will require stable oils, with demonstrated ability to maintain an appropriate level of thickness at high operating temperatures. Following a thorough analysis of the situation, the Mobil technical experts, recommended that Rajashree Cement use to the new Mobil Industrial Lubricant product - the Mobil SHC™¢ 639, a polyalphaolefins based fully synthetic bearing lubricant that demonstrated improved viscometrics at varying high temperatures

    Improving productivity and reliability
    Rajashree Cements was already a customer of ExxonMobil™¢. They had experienced the benefits of using Planned Engineering Service (PES), under which they used Mobil SHC 639 in one of their PA fans (thermal power plant). The oil exhibited excellent oxidation resistance that occurs at high temperatures and its low traction co-efficient helps save energy and reduce operating temperature. Mobil SHC 639 was the ideal solution for the current problem of operating with high temperature and load from the kiln, thereby ensuring enhanced reliability and reduction in tripping of the machine.

    Developed through extensive research and development, and in-service field testing, the application of Mobil SHC 639 helped to reduce the bearing temperature of the kiln by 10°C, and maintained an appropriate level of viscosity at high operating temperature.

    Though switching to Mobil SHC involved a higher cost outlay for Rajashree Cement, the premium paid was negligible when compared to a 2.5 times increase in the oil drain interval and overall reduction in the tripping of the machinery. This improved productivity led to recovery of the overall cost in no time as the extended oil change also enabled the company to achieve considerable savings through improved productivity and reliability of the kiln. Though Rajashree Cement had been using the ISO VG 460 mineral oil for many years, the significant results provided by Mobil SHC 639 drove the company to take full advantage of the benefits obtained from the newly deployed synthetic oil.

    Following the successful completion of the change, Rajashree Cement team member said, "The change has been seamless. The Mobil Industrial Lubricant product not only enhances the productivity levels of the machine, but also provides increased productivity and higher cost efficiency."

    Mobil SHC 639 reduces costs, maximises productivity
    For Rajashree Cement, the results from the new Mobil SHC 639 were outstanding, and the company saw its machine efficiency double. In addition, the durability of Mobil SHC 639 delivered increased equipment availability, enabling the Rajashree Cement to maximise its productivity, and save more than S$30,000/kiln annually by reducing the number of oil changes, and creating less waste oil. The company has been using Mobil SHC 639 since Q4 2008 and there has been no incident of kiln tripping, oil drain, contamination or oxidation, etc. The composite benefits achieved by using Mobil SHC 639 are as follows:
  • Improved productivity and reliability of Kiln
  • The bearing temperature reduced by 10°C
  • Oil drain interval increased by more than 2.5 times
  • Speaking on MIL's success in providing a solution to Rajashree Cement requirements, Shankar Karnik, General Manager - Industrial, ExxonMobil Lubricants Private Limited, said, "Mobil Industrial Lubricants has partnered with all the leading companies across sectors, and has a long tradition of providing innovative solutions to all its customers after understanding the core issue. The results delivered by Mobil SHC 639 for Rajashree Cement are perfect examples of how ExxonMobil's technology leadership and exceptional application expertise can deliver significant financial value and help companies increase their productivity."

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