Drive Retrofit of Sugar Centrifuge Shortens Cycle Times

8/12/2019 Drive Retrofit of Sugar Centrifuge Shortens Cycle Times

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Case Study:

ABB drive retrofit boosts production and uptime at Sugar CaneGrowers Cooperative of Florida

(Industrial regenerative drive retrofit provides 20 percent savings in cycle time andincreases throughput significantly)

The Sugar Cane Growers Cooperative of Florida is a 54-member sugar farmers cooperative that provides itsmembers assistance with agricultural administration and processing operations for their more than 70,000

acres of sugarcane. At its Belle Glade plant, 24,000 tons of sugar cane is ground daily, producing 350,000 tons

of raw sugar annually, on average. During the October through April harvest season, the plant operates 24

hours a day, seven days a week. Because sugar cane must be processed within a day of harvest, high throughput

is essential.

Key components in the multi-step process of converting cane into raw sugar are the sugar centrifuges, whichseparate crystals of sugar from sugar syrups. As the centrifuge spins at a rate of 45 to 1,200 RPM, the syrup(molasses) is forced out through perforations in the centrifuge wall, and raw sugar is left. The centrifuges drivecontrols the speed of the machine, ensuring maximum moisture is extracted.

After the 2003 harvest, the Sugar Cane Growers Cooperative decided to replace the drive control on a Titan 1750centrifuge, which has a 450 hp motor, one of the operations two largest centrifuges. The existing drive wasoutdated and was subject to frequent and expensive repairs, resulting in shutdowns that reduced productioncapacity. Because space was at a premium, they wanted a drive system with a compact footprint that would workwith the existing OEM-supplied control configuration.

Our previous unit failed at least once or twice a year, costing us thousands of dollars in replacement parts. Plus,when the centrifuge went down, it crippled the entire production line, explains Jose Mena, chief electrical engineerat the Belle Glade plant. We needed a drive system that was reliable, in addition to a drive that could re-harness thepower lost when the centrifuge recycled.

The solution: ABBs stand-alone industrial ACS 800-17 low-voltage drive for speed and torque control the first ofits kind installed in a sugar-processing facility. We retrofitted with this drive, because it offered the Sugar CaneGrowers processing plant everything they needed a compact drive footprint, regenerative capability, and exactmotor sizing, says Chris Visage, an ABB Low-Voltage Drives territory manager at Hummel Industrial Sales (Ft.Lauderdale). The resulting improvement in cycle time will increase throughput and eliminate bottlenecks at thecentrifuge, without adding a new larger motor, he noted.

Shortened Cycle Time Means Increased Production

The drive provides precise, rapid motor-speed response based on exact variations of the centrifuge load and thisdirect torque control immediately accelerated the centrifuge cycle time from 44 to 32 seconds, a 20 percent savings


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over the previous drive. Direct torque control enables the drive to calculate the torque and flux of the motor 40,000times per second, quickly slowing the load down at end of cycle, saving seconds in unload/reload operations.Additional time and energy savings are realized, as the energy from the spinning centrifuge, which turns the motorinto a generator, is recovered and transferred via the drive to an adjacent centrifuge. (This energy is dissipated asheat, in installations that do not utilize regenerative drives.)

Stable Ride Through Unstable Conditions

The ACS 800-17 also enables motors to run at full power at full motor voltage in 80 percent brownout conditions.This ride-through ability means that, even when theres a dramatic short-term reduction in voltage, the drivesustains full power for uninterrupted operation. In operating conditions where line voltage from a utility varies, thisbenefit helps ensure constant, optimum throughput. The ACS 800-17 employs an IGBT active front end, which isfar more robust than traditional SCR front ends. (SCR front ends are susceptible to inversion faults, which occurwhen the line power fails during a regenerative stop at the end of the spin cycle. It is not uncommon for suchinversion faults to cause extended down times.) The IGBT front end, in conjunction with the microprocessorcontrol of the ACS 800-17, can be shut down safely, to prevent damage to the drive, should a power failure occur

during a regenerative stop. The technology advance makes catastrophic inversion faults a thing of the past.

A Perfect Match to Existing Equipment

Because uptime is paramount during harvest, it was crucial to complete the retrofit installation before the seasonbegan. We were able to install and test this system in five working days time, meeting the co-ops deadline with amonth to spare, Visage says.

Installation time was shortened because ABB matched the existing control system from the OEM without using anyrelays, outside control interfaces, or PLCs. Our ABB ACS 800-17 regenerative line was able to drive the motorand match the input power supply precisely, eliminating any additional spikes or fluctuations, Visage says.Because the throughput has increased, the co-op will be able to use the existing motor to the fullest, instead ofdissipating much of the energy, which was the case with their prior drive.

The drive cabinet is in a confined area, so a compact footprint was vital. ABBs modular design provided a 40percent savings in floor space over the previous unit, and the modular construction of the drive makes maintenanceand repairs easier.

Software Aids Ease of Operation

ABB keypads and software designs facilitate smooth and accurate operation and maintenance, because they offerthe capability to store programming within the removable keypad. This eliminates guesswork when the drive isreprogrammed after service. Parameters are simply downloaded from ABBs unique user-saved position. In

addition, exact run times are easily accessible by keypad, which promotes systematic maintenance scheduling andfewer secondary failures such as clogged filters.

ABB has provided us a reliable product and an excellent service team, Mena says. Because we have other ABBproducts at the plant, we knew the reliability factor and anticipated no downtime with the retrofit.

Local Support / Local Service

Sugar Cane Growers Cooperative worked closely with Miller Bearings, Inc., an industrial distributor for ABBproducts in Florida (http://www.millerbearings.com). Because the distributorship is factory certified DSS (DriveService Station), providing maintenance and service for drive installations like these also is available, if needed.


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Throughout the project for Sugar Can Growers Cooperative, a team consisting of Miller Bearings, ABB engineersand sales managers collaborated from start to finish, to size the drive, plan the installation, and commission thedrive, ensuring total customer satisfaction.

ABB Inc., Automation Technologies, Automation Products, Low-Voltage Drives, is the world's largestmanufacturer of electric motors and drives. In the USA, an integrated channel of sales representatives, distributors,and system integrators allow ABB, New Berlin, Wisconsin, to supply a complete line of energy-efficient electricdrives, motors and engineered drive systems to a wide range of industrial and commercial customers. Productsmanufactured include AC and DC variable speed drives for electric motors from 1/8th through 135,000 HP, andapplication-specific drive system solutions to meet diverse customer needs (http://www.abb-drives.com).

ABB (www.abb.us) is a leader in power and automation technologies that enable utility and industry customers toimprove performance while lowering environmental impact. The ABB Group of companies operates in around 100countries and employs about 115,000 people. The company's U.S. operations employ about 9,000 in manufacturingand other facilities in 40 states.

Retrofit of sugar centrifuge gets underway.


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Centrifuge bowl inside the outer casing.

Syrup flows through the perforated centrifuge bowl, as it is spun.


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The motor mounted above the centrifuge spins the bowl at high speeds during the separating process.


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The footprint of the newly installed ABB industrial regenerative drive ACS 800-17 is 40% smaller than previousunit.

For more information please contact:

For Information Regarding the InstallationChris VisageHummel IndustrialFort Lauderdale, FL954-444-6561 (mobile)[email protected]

ABB Media RelationsKen GraberLV Drives, 16250 W Glendale St. New Berlin, WI262-780-3873 phone262-785-8501 [email protected]

Drive Retrofit of Sugar Centrifuge Shortens Cycle Times

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