engineering shops and foundry in vizag steel plant ppt

[dhanabhagya]

Steel has always been the backbone of nation's economy.From an annual production of 13 million ton in 1900, global steel productionraised to 300 million ton in 1950 and to 842 million ton in 2000. Indiaproduces 30 million ton per annum from 9 major plants. The major steelplants contribute 19 million tones and the rest is contributed by secondarysector. Visakhapatnam Steel Plant is one of the 6 integrated steel plantscontributing 3.51 million ton of liquid steel per annum. It is the only steelplant in India accredited with ISO 9001, ISO 14001, and OHSAS 18001certificates for Quality environment and Safety aspects of the steel makingactivities. With the improvement in operating performance of major unitsand efficient maintenance and material handling system the plant has madea turn around and achieved net profit of 2100 crore rupees during thecurrent fiscal 2004-05. This project deals with the Design verification of critical Trunnionring of a process equipment LD Converter used for steel making process. TheLD converter is a steel shell lined with refractory material used for handlingthe molten steel at 1650° C. The vessel is suspended on a trunnion ring withfour numbers of tie rods and rotates at 0.1-1.0 RPM by means of four hungreducers and one special reducer with motors of 4 - 172KW DC. The trunnionring is box section with plates 140mm having forged end journals and theentire assembly weighs around 147 Tons carrying 1000 Tons of vessel withhot metal. The linear dimension of the trunnion ring will be around 14 Metersand the straightness of the surface should be 1 mm over 1000mm span.General norms of the life of the trunnion is around 1 0 Years but the it is tobe changed with the survey readings if the deformation exceeds the limit. Inconverter No.1, the survey readings depicted around 20mm deformation andis to be changed in a planned shutdown as the repair takes around 40 daysshutdown of the process equipment. Keeping this in mind a new trunnionring was imported from the Russia and is observed the changes in the design

compared to the existing trunnion in the hole sizes 0300 fTom 0180. It isnecessary to verify the design before implementation about the safety of thesystem.In this regard after visiting the site and collecting the necessarydimensions a 3Dimensional modeling using CATIA has been done for theexisting and modified design. Also the model has been imported to ANSYSand the von-mises stresses have been obtained by applying fixed supportconstraintand loading conditions and the stresses induced in the trunnion ring isaround 25.32 N/mm2 in the existing trunnion and 36.5 N/mm2 in themodified trunnion ring. With the material of ASTM-A36 of the trunnion, theexisting Factor of safety is reduced fTom 11 to 8 and as per the norms forthe structural the allowed factor of safety shall be above 5. Hence thedesign is safe for the operation. The data is presented with 3D model of objects, meshed images and von-misesstresses. The present analysis was done only in static case. This can befurtherextended to dynamics considering the rotation of the trunnion ring.