Cement, Energy and Environment July-Sep 2002

I . TECHNOLOGY UPGRADATION PROCESS & OPERATION i\llJLTIPLICATION AND DIVISION FOR EN(;Il\IEERS R. Farnish, U. K. In many plants around Europe, the requirement exists to obtain mu lti ple produc t stre ams from storage vessels. AIthough this may seem like a fairly simply achieved requirement, there are many ways in which product processes can be adversely affected as a direct result of th e tec hniqu e appli ed fo r obtaining additional material feeds. This article wi ll therefore examine some of the more frequently seen approaches and provide an insight into the "best practice" approaches that should be considered by plant operators and managers. Faced with a vesse l from which an additional product stream is requi red, th e re are severa l approaches that are commonly adopted, these be ing to spil t the product stream after it has passed through the existing outlet, simpl y add as may outlets as required to the vessel or to mechanically extract from the vessel. That additi onal product streams will be created is guara nteed - but what other prob lems wil l accompa ny these measures? In order to appreciate the natu re of the problems that may be generated it is useful for the reader to reacquaint themselves with the basic features ofcore tlow and mass flow. Courtesy: Powder handling processing, Vol. 1./. No. 1., Jm1-tlfar 02, Pp. 26-28 Fax: +./9 5323 969 796 J::ma11: ttp(£!!1ranstech-onli11e. com II 'eh: 11'11'11'./ratTSiec h-online.com I COi\IPARISON OF DIFFERENT FEEDING DEVICES FOR VERTICAL AND STEEPLY INCLINED CO~ \'EYING IN SCRE\V CO'IVERYORS F. Kess ler, J. Leitner and E. Lichtenecker, Austria Screw conveyors are not only used for hori zontal but .also for verti ca l and steepl y inc lined conveying of bu lk materials. The design of a screw conveyor is rather simple, nevertheless a number of relevant variables caused problems during the construction of this type of convey ing system . Today's powerful computers and the wider kn owledge base enabl e us to consider the intluence of important va riables, like, e.g., diameter, pitch and rotation speed of the screw, or the various properties of the bulk material, on calcul ating the volume fl ow and the power requirements of a vertical screw conveyor. For the practical use of such conveyors, it is also important to select the appropriate type offeeder. Vertical screw conveyors are often fed usi ng the entire screw circumference as intake (surround in take). With inc reasing intake length the load in the conveyor and, consequen tl y, th e vo lume of materi al to be conveyed, increases. Another way to increase the mass flow is utili zati on of con ica l transport sections (funnels) in the intake area. Feedin g can also be accomplished by using a second horizonta l sc rew .conveyor to directly convey the material to the intake area of th e vertical screw conveyor. In case the horizontal screw has the same shaft and screw diameter as the ve11ical screw, the hori zontal feed ing conveyor has to be operated at a lower speed than the verti cal or inclined conveyor. Courte:.y: Bulk Solids Handling, Vol. 22 (2002) No. 2. Mar .-Ap/.02, P 108. Fax: +./9 5323 969 - 96 Email: ttp@tronstech-online.com Web: 11'1vw. transtech-onfine.com UPGRADATION OF ZUARI CEMENT PL~N.T Lalji Srivastave, Zuari Cement, Pafle Gry dgaard, F.L. Smid th &Co., Jayanta Saha and Rakesh Shrama, L& T, Building a new g reenfi e ld cement plant in today ·s scenario can be an expensive propos ition. One of the alternati ves is to upgrade the existi ng plant to utilise the available equipment to full potential and add eq ui pment wherever requ ired fo r balancing the capacity. This way the overall economy is possible since th e ex i s t~n g manpower, in fras truct ure, colony, etc, can be optim a ll y utili sed. The paper d iscusses th e upgradation of a cement plant lead ing to a reduction in thermal energy consumption. Texmaco Lim ited, Yerragunt a la was fi rst commi ss ioned in 1985 with a capacity of 1.500 tpd clinker. Main equipment consisted ofsingle stri ng 4-stage cyclone preheater (SP), kiln of 4.55m diameter x 68m long, grate cooler, close circuit ball mill systems for grindi ng raw meal as well as fine coal and open circuit combidan mi ll for cement grindi ng. Complete plan t mac hi nery was des igned and supplied by F.L. Smidth Denmark and La rse n & To ubro Limited, India. Heat and e lectrical power consump ti on were 875 kCal/kg c linke r and 150 kWh/T OPC respectively. Dust emission through main stack was - 140 mG!Nm' . .. - -