Cementos Cruz Azul (Blue Cross Cement) recently constructed a new cement plant near the town of Palmar del Bravo, about 50 miles south of the city of Puebla. Electrical power was needed for equipment testing and production startup but it was not locally available. The local electric utility was experiencing delays in building a transmission line to supply the plant, so Cementos Cruz Azul turned to Cummins Power Generation for help in supplying the temporary electric power needed.

“The new state-of-the-art cement plant was constructed, but there was no utility power available to test the plant's motors, fans, conveyors, crushers, and rotating kilns,” said Oswaldo Chimal, sales manager, Mexico and Central America, Rental Business, Cummins Power Generation. To complete the testing and begin limited production, Cummins Power Generation was contracted to supply 13 Rental Power units with approximately 15 MW of generating capacity for about six months.

ENERGY INTENSIVE

In the process of making cement, limestone, clay and other minerals large electric motors are required to operate the crushers, rotate the massive kilns, and power the induced draft fans. According to Ignacio Cruz, plant manager at Cementos Cruz Azul, the plant will require about 32 MW of utility power when it is in full production.

Operating at capacity, the plant will produce 3,000 tpd of cement using limestone from the local area's deposits — as thick as 1,000 feet — as a major raw material. The new plant will be the fourth and also the most modern and efficient cement plant in Mexico built by Cementos Cruz Azul, a company that was started more than a century ago.

The Rental Power units supplied by Cummins consisted of two 2-MW trailerized generator sets and eleven 1-MW trailerized units, each having a complete power system generator, monitoring control, automatic transfer switch, and switchgear. For the first four months during the equipment testing phase, the Rental Power units only operated for one shift, or about eight hours per day. The electrical testing included operating 2,800-kW electric motors and motors with variable-frequency drives. In addition to testing the 13.8-kV to 4.16-kV main transformers, all control and communications equipment was thoroughly tested with the Rental Power units.

When the initial equipment testing was completed, the plant began processing raw materials to test the production capabilities. For the next two months, the plant was producing limited amounts of cement by operating the Rental Power units for two shifts, or 16 hours per day.

“We tested all of the plant's equipment by actually processing raw materials into cement, so we could be assured of a good final product,” said Cruz. “During this initial test production period, we produced 25,000 tons of clinker and 5,000 tons of finished cement using the Rental Power units. This production testing allowed our plant to begin manufacturing cement six to eight months earlier than if we had waited for utility power.”

The periodic maintenance of the Rental Power units is handled by the local Cummins distributor, Converto Dexel, while daily refueling is handled by the cement plant personnel and a local fuel supplier. “When we were only operating the generators for eight hours a day, we scheduled oil and filter changes two times a month,” explained Chimal. “When we were operating the generators for 16 hours per day, we increased our maintenance to three times a month.”

With help from Cummins and its Rental Power units, Cementos Cruz Azul was able to complete its equipment testing and begin limited cement production while the new transmission line was being constructed. When the Federal Commission of Electricity (CFE) was able to supply utility power at the end of February 2007, the plant was immediately able to operate at 80 percent of its full capacity. This saved the company time and money, leading plant manager Cruz to conclude: “The rental generators worked very well for us.”

This article was adapted from material provided by Cummins Power Generation. For more information, contact Debby Wadsworth, Cummins Power Generation, 1400 73rd Ave. NE, Minneapolis, Minn. 55432; (+1) 763-574-5395; fax: (+1) 763-574-5811; www.cumminspower.com/rental.