Mod Drive Improves Airport Baggage Conveyor Systems
FAIRBANKS INTERNATIONAL AIRPORT BAGGAGE TRANSPORT CONVEYOR ENHANCED WITH MOD DRIVE™ SYSTEM
REGAL REXNORD SOLUTION PROVIDES ENERGY SAVINGS WHILE SIMPLIFYING INVENTORY AND MAINTENANCE
By Laura J. Merrison, BSEE, Power Electronics Design Engineer IIIRelated Documents
Airports face a host of unique industry challenges, such as meeting efficiency regulations and seeking out the best maintenance practices to reduce costs and keep operations flowing. In today’s current economic climate, any potential cost savings can go a long way.
In 2019, Alaska’s Fairbanks International Airport (FAI) sought to modernize its equipment and operations. They were dissatisfied with the performance of the gearmotors on their baggage transport conveyors and began searching for new suppliers. Regal Rexnord approached FAI with a solution that could improve equipment performance and simplify maintenance, with the added benefit of energy cost savings: the Hub City® MOD Drive™ system.
The MOD Drive system, developed specifically for conveyance applications, is capable of starting and accelerating loads requiring up to three times the rated torque at start. Its modular configuration allows for a range of different mounting orientations, power and torque ratings, keyed or keyless output bores, and other unique customizations. Its modular design also facilitates reduced maintenance time and cost.
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VFD |
Onboard VFD designed for control of permanent magnet motors using a sensor-less control algorithm. Operates at 480V, three-phase. |
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GEARBOX |
Hub City® HERA® (high-efficiency right angle) gearbox. Comes in a variety of ratios to meet customer application speed and torque requirements. |
Table 1: Component descriptions
ENERGY EFFICIENCY OF THE MOD DRIVE SYSTEM
The Regal Rexnord team shared with FAI operators the potential energy savings the MOD Drive system could generate. The existing installation on the conveyor lines had a motor with across-the-line starting, i.e., it pulls six to eight times rated motor amperage from the power source to achieve starting torque. This means the motor has hard starts and stops that can cause wear on all of the conveyor’s components. However, VFDs provide starting torque without exceeding the nameplated current. This reduces the amount of energy needed to start the motor, resulting in softer starts and stops and longer product life.
Furthermore, airports lease space to users, such as coffee chains, gift shops and concessions, on an energy-demand basis (i.e., charges per electrical outlet). Every user is utilizing a limited amount of power available on-site. Energy savings extrapolated to the baggage handling system — the largest consumer of energy in the airport — would help airlines and operators see cost savings on multiple fronts. Most of Alaska’s power generation comes from diesel and coal, so any power savings realized by the airport is a potential environmental benefit.
The Regal Rexnord team was given a chance to prove the MOD Drive system’s benefits to FAI. They set up a comparative test to validate and quantify claims against the original gearmotor to evaluate energy consumption, starting current and overall performance.
A MOD Drive unit was installed on one conveyor line and compared to a “sister” conveyor fitted with the current gearmotor setup. While the standard MOD Drive unit consists of a 2-horsepower motor, size 1 VFD, and a HERA 45 gearbox, the MOD Drive system installed at FAI was a 5-horsepower motor with a size 2 drive and 180FR motor to match the power rating of the original equipment. The MOD Drive system was equipped with mounting provisions to allow direct replacement of the original drive system without modifications to the conveyor.
Power meters connected to a cell modem were installed on both the MOD Drive system and a “sister” conveyor fitted with the current gearmotor setup. The cell modem allowed the team to monitor data collection and change power meter parameters in real time throughout the duration of the test. The meters ran for a month to collect data.
Existing gearmotor setup
MOD Drive system
TEST RESULTS
When the Regal Rexnord team started looking at the data from the install, it was immediately apparent that the MOD Drive system was saving energy and giving the mechanical system a break. The ramped acceleration and deceleration, soft start and stop, and optimized energy savings algorithm in the VFD were making a difference.
The test data showed that the energy required to start a load with the MOD Drive system’s VFD is about 30% of what is needed to run the same load with the existing gearmotor that starts across the line. FAI has several other units like the one replaced by Regal Rexnord. According to energy usage, cost-per-cycle findings, and the number of gearmotors, FAI has the potential to realize significant energy cost savings.
The cost savings shown below are based on actual energy audit data collected by Regal Rexnord’s engineering team. A “cycle” in the tables below represents energy consumption per plane load of bags.
FAI’s current gearmotor setup costs approximately $200 per gearmotor per month. The cost with a MOD Drive system was calculated as about $98 per gearmotor per month, resulting in a monthly savings of just over $100 per gearmotor. With 38 gearmotors currently installed, the total yearly savings could approach $47,000.
Present case
Usage and Cost
|
# of cycles |
Energy usage |
GVEA rate |
GVEA |
|
63 |
0.5205 |
$0.04466 |
$0.10965 |
|
Energy cost per |
GEVA's flast |
Energy cost per |
|
$6.73 |
$50.00 |
$201.80 |
Table 2: Energy usage based on Regal Rexnord energy audit. Calculations use hourly kWh rates from the Golden Valley Electric Association (GVEA).
Future case with MOD Drive system
Usage and Cost
|
# of cycles |
Energy usage |
GVEA rate |
GVEA |
|
63 |
0.5205 |
$0.04466 |
$0.10965 |
|
Energy cost per |
GEVA's flast |
Energy cost per |
|
$3.27 |
$50.00 |
$98.12 |
Table 3: Energy usage based on Regal Rexnord energy audit. Calculations use hourly kWh rates from the Golden Valley Electric Association (GVEA).
Savings for FAI
|
Total monthly savings with MOD Drive system (per gearmotor) |
$103.68 |
|
Total annual savings with MOD Drive system (per gearmotor) |
$1,244.16 |
|
Number of FAI gearmotors |
38 |
|
Total monthly savings for FAI (entire system) |
$3,939.84 |
|
Total annual savings for FAI (entire system) |
$47,278.13 |
|
Table 4: Calculation based on numbers of gearmotor units and starts per day
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|
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MOD Drive energy savings |
68% |
Airports found in metropolitan areas that carry more passengers and baggage would realize more energy savings. In places such as Miami and New York City, baggage handling conveyors number in the hundreds.
FAVORABLE RESULTS
FAI was pleased with the outcome of the comparative test, as well as the other benefits of the MOD Drive system. They are expecting longer equipment life, not just on the gearmotor but other components of the conveyor, such as the bearing and shafting. The versatility of the MOD Drive system also means that it can handle different ratios, horsepower and mountings, meaning there are fewer SKUs to manage.
The MOD Drive system provides overall energy savings to FAI, while simplifying inventory and maintenance.
For more information or to contact our experts and inquire about how the MOD Drive system can simplify maintenance and save energy, visit the product page today.