Belt Cleaning Technology Mexican Cement Manufacturer Addresses Conveyor Carryback
A world leader in conveyor bulk handling solutions has used its innovative belt cleaning technology to help a cement manufacturer resolve fugitive material buildup caused by a variety of alternative fuel resources (AFRs).
Mexico’s second largest cement producer, Holcim Mexico increased the use of solid and liquid AFRs at one of its facilities, but the change resulted in spillage and carryback that caused equipment failures, cleanup and maintenance costs estimated at $ 67,000 per month. The solution from Martin Engineering Mexico has significantly decreased the amount of spillage, increased workplace safety and lowered the cost of operation.
Located in southeastern Mexico, the Planta Macuspana facility produces 1 million metric tons (1,102,311 tons) of cement annually. Out of Holcim’s total annual output of 12.6 million metric tons (13,889,123 tons) from seven operating plants, nearly 14 percent of the total thermal energy demand was fulfilled by the use of AFRs in 2013.
Using 1990 as a benchmark, the corporation’s entire Mexican cement production has more than doubled, with an increased annual energy consumption of only 45 percent, reducing CO2 emissions per ton of cement by 25 percent. However, maintenance costs threatened to offset the economic benefits of the program.
Several Types of Carryback
Delivered in both solid and liquid forms on seven 40-inch-wide (102 cm) conveyor systems, 1.5 metric tons (1.65 tons) of solid waste and 21 metric tons (23 tons) of sludge are carried per hour to the calcinator. Solid waste products including paper, wood, plastics and shredded tires are run through a crusher and measured for caloric content (the amount of energy contained within a substance). Consisting of petroleum slurry and contaminated water, the liquid waste is mixed with sawdust and dried before also being measured for caloric content. After processing, the mix is loaded into a feed hopper, passed over a belt scale and distributed by a mechanical feed valve onto the conveyors.
Prior to implementing the Martin Engineering components, the Macuspana facility utilized a mix of belt cleaners without tensioners and cleaning systems fabricated in-house, with ineffective results. Spilling approximately 6 tons (5.4 metric tons) of solid and liquid material per month, the process had to be monitored by a full-time employee who reported daily on spillage volume and potential hazards. Twice per month a four-person crew required a full shift of downtime to clean up piles of material and sludge from around the conveyor frame.