Imported energy carriers can now be replaced at an increasing rate by low-cost locally available alternative fuels such as biomass, tire chips or sewage sludge. Arabian Cement (ACC) is a leading cement company located in the Governorate of Suez, in north-eastern Egypt. Up to five million tons of high quality cement leave ACC every year in support of the local market. In addition, high quality concrete products are provided by Andalus Ready Mix Concrete, an ACC subsidiary. ACC is listed on the Egyptian Stock Exchange and recently expanded operations to Brazil.
ACC is already using 12 % alternative fuels in 2015.
”The entire system is fully automated and includes primary storage and shredder system, magnetic separation, transportation to the intermediate storage area, a discharge system from intermediate storage, a gravimetric dosing system and an injection system into the kiln precalciner“, explains Adel Ezzat, Alternative Fuel Manager at Arabian Cement. In the ACC installation in Egypt, alternative fuels can substitute up to 30 percent of conventional fuels, mainly imported coal. “Starting with a seven-percent substitution rate in 2013, ACC is already using 12 percent alternative fuels in 2015, with similar annual increases planned in the coming years”, Adel Ezzat elaborates. Where there is great flexibility in materials available, production machinery must follow suit. The rotor weighfeeder Pfister ® TRW-S/D is designed for a broad variety of alternative fuel installations and reliably performs pneumatic material feeding to kiln burners or mechanical material transport into calciner inlets.
The challenge with alternative fuels: they never come in a completely homogenous masses. Like, for example, in an Irish cement plant which fires RDF with wood waste to the calciner. These wood particles vary considerably in size but are still accurately dosed and passed on by rotor weigh-feeder Pfister® TRW-S/D. Experience shows that hardly any alternative bulk material is delivered without any foreign bodies included. Plus, in some cases, the plants pre-preparation of the material might fail. This is why FLSmidth Pfister is elaborately testing all different kinds of alternative fuels as well as different sizes and bulk densities at their own test stands. Those tests showed that the elaborate design of the rotor weighfeeder Pfister® TRW-S/D prevents blockages even when unexpected foreign bodies are included in the material. The biggest foreign body at the test stand was even 300 x 300 x 10 mm in size. Tire-shreddings with steel wiring, long corn straw, even liquid- illed plastic bottles in the material mixes did not effect the weighfeeders performance. Smart design and experience in the field make Pfister® weighfeeders sturdy and reliable additions in the production lines of cement and lime manufacturers around the globe.
So a convincing asset of rotor weighfeeder Pfister® TRW-S/D is that it is able to dose varying secondary fuels in a wide density range (70 kg/m3 – 700 kg/m3) as well as weight range (1:10) with one and the same system. Virtually each and every alternative fuel bulk material can be employed without any rebuilding of the weighfeeder. Its simple, no-nonsense design with no unnecessary frills makes rotor weighfeeder Pfister® TRW-S/D a sturdy workhorse with low maintenance and high reliability. With the help of a special stirrer the material is loosened and falls out of the pre hopper, without any compression, into the rotor chambers. The weighing and dosing principle of all Pfister rotor weighfeeders is the same: By means of a weighing axis the material weight is gravimetrically determined before material discharge, providing for a highly accurate and consistent mass stream to the pyro process.
Fuel selection as a crucial aspectWhen it comes to properly feeding the great variety of alternative fuel materials into the burner, rotor weighfeeder Pfister® TRW-S/D has proven its efficiency in more than 240 implementations worldwide. In 44 countries plant management chose the FLSmidth Pfister® multifuel dosing concept for reliable and flexible low-maintenance operations. The greatest challenge in dosing alternative fuels is their diversity. Particle size, density and water content are never the same. Refuse-derived fuels (RDF) are fluffy, fibrous or compressible, biomass or sewage sludge may contain additional moisture. Not only in the start-up phase FLSmidth Pfister experts in alternative fuels are assisting customers setting up the material demand profile for their respective suppliers and make sure that materials and technical set-up are a smooth match.
Summary: Now future-oriented with Pfister technologyACC can now use various locally available fuels to cut overall energy costs and minimize its dependency on the expensive import of energy carriers. The company can react to market changes and purchase the fuels which are available at surplus while, at the same time, help to protect the environment. ”Materials which would otherwise end up in landfills are being put to economically intelligent use“, FLSmidth Pfister project manager and Area Sales Manager Hassan Jrady wraps up ACCs win-win situation created by Pfister® technology and knowledge.
Technical data alternative fuel dosing rotor weighfeeder Pfister® TRW-S/D installation at Arabian Cement/Egypt
|Alternative fuels||Mixture of dried sewage sludge (DSS) and municipal solid waste|
|(MSW) like plastics, rubber, packing materia|
|Mass flow||up to 12t/h|
|MSW grain size 2D||98 wt.% < 50 x 50 mm,100 wt % < 150 x 150 mm|
|Bulk density||0.1 – 0.6 t/m3|
|Water content||max. 25 %|
|DSS grain size||up to 10 x 10 x 10 mm|
|Bulk density||0.5 – 0.7 t/m3|
|Water content||max. 12 %|
FLSmidth Pfister GmbH: Decades of dosing experience
Stable and accurate dosing of secondary fuels is one of the key elements required to produce clinker profitably and efficiently. With its multi-fuel rotor weighfeeder Pfister® TRW-S/D concept, FLSmidth Pfister is offering a future oriented technology that is able to dose up to 25 tph. With more than 240 installations worldwide, customers of FLSmidth Pfister are feeding many million tpa of secondary fuels. FLSmidth Pfister GmbH does not only supply the single dosing machines. FLSmidth Pfister’s know-how includes the complete setup and surrounding of the installation like silo engineering, intermediate material transport and safety equipment. That ensures that customers get all engineering from one experience partner and one single source.
FLSmdith Pfister, Germany