By replacing the four-phase ABB ACS 5000 frequency inverter to control the speed of the exhaust fan at the Saraburi Cement Plant Project of Siam City Cement Company, the second largest cement factory in Thailand, has helped save about $ 250,000 a year. 
With each 2.5-megawatt (MW) inverter, the flow of gas from the furnace to a series of cyclones in the pre-heater tower is designed to heat the material before it is put into the furnace to help save energy and quantity.

ABB ACS5000 inverter controls the inlet fan

The inlet fan is a major electrical energy consuming device and was previously controlled by sub-synchronous subassemblies with limited operating range that limited the plant's production capacity. At the moment, the fan speed is controlled in the range of 60-100% of the maximum power, but when using the new solution using the inverter, they can operate in the maximum range from 0 -100%, it offers greater flexibility in production for plant operation engineers.

Engines and exhaust fans at Siam City Cement Plant

The operating cost of the plant is also affected by the life span of the adapter when the brushes on the machine need to be replaced once a month and the spare parts become increasingly scarce. In order to replace the brushes, it is usually necessary to switch off the shredder to ensure that the shear adapter can be operated 24 hours a day to meet the requirements of continuous cement production. The shutdown time involves writing a burner operation interrupt, which costs several thousand dollars a year. 
Immediate effect of installing ABB inverter and The ACS 5000 in the plant is a significant annual energy cost reduction, which saves up to 2,500 MWh of annual electricity, reducing annual CO2 emissions by up to 1,250 tons. Moreover, lower maintenance, maintenance costs and higher reliability limit the engine shutdown and thus eliminates the motor's rotor, which is unnecessary, reducing maintenance costs. In addition, the ABB ACS 5000 inverter has a continuous control feature that allows the inverter to operate continuously even when system voltage fluctuations persist for a long time.

Source: Automation Vietnam