BMM Ispat is a Rs 2,000-crore company, part of the renowned BMM Group. The plant at Danapur, Hospet, Karnataka is a true blue steel plant manufacturing high-quality steel products. As part of a new brownfield project, the company is planning to expand the existing capacity, for which ElectroMech is supplying 13 cranes in the first phase. This facility is being constructed to expand the product range and to include a semi-automatic process, which will increase production. BMM Ispat approached ElectroMech during the summer of 2012 and after a thorough evaluation of a proposal, placed an order for 13 cranes to be used at various stages of their manufacturing process. Through a detailed understanding of their workflow and several interactions between both the teams, cranes of most efficient design, effectively matching the application requirements were selected.

Steel melting shop: The first area is called the steel melting shop, which handles all the operations from the melting of raw material to forming of billets of desired shape and size. Here the metal is processed in the molten form and handled by ladles. The formed billets are to be rotated in 90? and are to be transferred on the idle rollers to take them to two different storage locations.

Furnace and rolling mills: The second phase of the entire process consists of furnace and rolling mills and includes handling of long metal billets of an average length of 12 m each. The process is initiated by passing the billets on to idle rollers installed besides the furnace. The rolling facility is spread over 200 m length and the preheated billets are passed through various horizontal and vertical rolling mills to give them the desired shape. The dies of the presses are required to be changed frequently to suit the particular product to be rolled, which includes rolled angles, TMT bars, metal rods and I-beams.

Quenching and cooling: The fourth and final phase includes the dispatch of the finished products. The dispatch yard is spread over 380 m long and 50 m wide area. This consists of parking bays for trucks and a railway track for loading on railway carriages. The dispatch area has to store and handle long rods and beams. Rotating crabs are used to control the angle of long metal bars and other similar components in the dispatch bay.

The processes and challenges: BMM Ispat?s plant is spread over a vast area of 50 acre (approx 200,000sq m) and the entire manufacturing process is divided into four stages. BMM Ispat was looking for a competent partner who could understand the challenges and design a complete material handling system to integrate the various processes. The objective was to ensure safe, quick and precise handling and appropriate manoeuvring during loading at the dispatch bay.

Solutions: ElectroMech responded to BMM Ispat?s challenge with some unique ideas. Detailed analysis, design iterations and trials resulted in an integrated solution that has proved to be foolproof, achieving the intended task swiftly. A total of 13 cranes were designed to handle the material through various processes right from the steel melting shop to the placement of bars and rods on railway carriages. In the steel melting shop (SMS) where billets are formed, four cranes with rotating trolleys assist in the manufacturing and storage of the billets. Two cranes of 20 MT each covering a span of 32.8 m and another two 20 MT cranes with 27.2 m span cover the manufacturing and storage of the billets before they are sent for further processing. Since these cranes are part of a process and in constant use, these are designed for Class 4 duty. The ambient temperature in the steel melting shop is approximately 60oC, requiring all the components of the crane to be able to withstand such high temperatures. Hence, a slewing wheel type of arrangement was selected to be able to work in this area. An air-conditioned cabin is also provided for the operator.

Furnace and rolling mills: The furnace is served by a 10 MT crane with 22 m span, which also has a rigorous initial application of installing the furnace and rollers. Once the installation of the furnace is completed, the crane will be used for replacing the rollers and for regular maintenance applications. Once the billets are transferred to the furnace for heat treatment purpose, they pass through idle rollers where they are re-heated. Two cranes serve this area; one crane of capacity 25/5 MT with 28 m span and another of 20/5 MT capacity and 34 m span. Since the dies have to be changed depending on the product to be manufactured, the 25/5 MT crane is in constant use. All these cranes are designed for Class 3 duty. Quenching and cooling: Rolling is followed by the quenching and cooling of rolled items. The material to be handled in this stage is in the form of bundles and the same continues till the dispatch of the final product. Here, two 15 MT, 28 m span, Class 3, double girder cranes are installed to assist the installation of the machinery during plant set u stage and later on will be used to handle the material being processed at this bay.

In the steel melting shop (SMS) where billets are formed, four cranes with rotating trolleys assist in the manufacturing and storage of the billets. Two cranes of 20 MT each covering a span of 32.8 m and another two 20 MT cranes with 27.2 m span cover the manufacturing and storage of the billets before they are sent for further processing. Since these cranes are part of a process and in constant use, these are designed for class 4 duty. The ambient temperature in the steel melting shop is approximately 60oC, requiring all the components of the crane to be able to withstand such high temperatures. Hence, a slewing wheel type of arrangement was selected to be able to work in this area. An air-conditioned cabin is also provided for the operator.

Dispatch
Once the processing of the material is complete, it moves towards the dispatch bay. The dispatch bay is 380 m in length and is entirely covered by three 12.5 MT, 34 m span, Class 3 duty cranes. Like in the case of the steel melting shop cranes, these cranes also have 360?rotating crabs, however, the mechanism used here is a slewing bearing. This mechanism was narrowed down upon after many discussions between the design team of ElectroMech and BMM team.

There were two types of rotating mechanisms that were finalised. One that operates with the help of gears and the other by using rails and wheels. The first one is used for continuous operations and hence the maintenance had to be kept to the lowest possible. The latter crane was operated under normal working conditions hence easy accessibility and simple mechanisms had to be provided. Since the dispatch bay is in continuous operation, the cranes installed here are used rigorously for loading of finished components. The other two cranes will be used to load and unload materials onto dispatch vehicles into the respective parking areas. The client team and ElectroMech team worked closely to develop a suitable system and commission it in the stipulated time span. BMM Ispat management appreciated the efforts and complimented ElectroMech team for its customer-centric approach.