CONVEYING
CDI innovation for Dune Express
At 67.8 km, Atlas Energy Solutions’ Dune Express overland conveyor system is the second longest chain of conveyors ever built and the longest built in 50 years. The conveyor system transports 1,905 t / h of frac sand across the Permian Basin and into New Mexico where it supplies remote distribution facilities. Conveyor Dynamics, Inc.( CDI) was responsible for the complete detailed mechanical design and mechanical drafting of the system but also deployed several new inventions on this project. Notably, Dune Express was the first conveyor globally to deploy the Conveyor Dynamics Ninja Idler Change invention. This invention allows operators to change idlers on a running conveyor without shutting the conveyor down dramatically increase conveyor availability.
This system comprises of two main tools, the Idler Change Arm( ICA) and the Belt Lifter( BL). The ICA can be readily disassembled into three main subassemblies( vertical carriage, horizontal rail and tool arm) for ease of handing and transportation on the conveyor maintenance
vehicle and handling. To minimise system cost, maximise flexibility of use and reliability, robotic arms were not used as has been attempted previously. Instead, a manual tool system was developed with hydraulic, electric, and pneumatic assistance.
To extract a roll, the maintenance personnel fasten the vertical carriage to the ground module H frame leg. This precisely locates the tool arm in 3D space relative to the idler transom frame regardless of module banking and orientation. The horizontal rail is then secured to the vertical carriage, and the tool arm with its pneumatic grippers is connected to the horizontal rail. The hydraulic powered belt lifter is attached to the end of the tool arm and deposited on a set of hooks on the conveyor module H frame.
To ensure the lifter is positioned at the correct elevation before it is swung between the belts, an interlocking mechanism prevents the tool arm from rotating into the plane of the operation unless it is at the correct elevation. The tool arm releases the lifter, leaving it on the hooks and is swung back to the operator away from the conveyor. Hydraulic cylinders on the lifter then lift the moving belt off the idlers. After the belt is lifted, the tool arm is moved to the pivot on the opposite side of the horizontal rail beam. It then swings behind the idler and pneumatic grippers are used to extract the transom frame while the belt is supported by the belt lifter.
Once the complete idler frame and roller assembly is rotated out of the plane of the operating conveyor then the idler rolls are replaced, and the process is repeated in reverse to reinstall. In total, six sets of Ninja Idler Change tool systems were supplied to Atlas for use on the Dune Express system. The original
The CDI Ninja Idler Change system system was designed to be disassembled and transported to a failed idler in a pickup truck. Atlas’ s dedicated idler change crews have since developed a cradle system that deploys Ninja with a service truck mounted jib crane. Their crew are using Ninja daily and are changing failed idler rolls while the conveyor is running in less than eight minutes.
TR-2011KS-07. This conveyor is just over 4.5 km in length. The first 1.5 km of the conveyor drops 215 m. The remaining 3 km traverses two moderate hills for an overall drop of another 15 m. Braking requirements for this conveyor were enormous and almost double that of any other conveyor currently in operation. The total installed braking torque is an incredible 3,610,000 N-m. This braking torque is divided among all seven drive pulleys. It is further split between less expensive, but faster acting, constant torque brakes and slower, but more costly, proportionally controlled bakes.
During operation the motor power is constantly monitored. Should a power failure occur, a set number of digital brakes are applied to provide the main braking force. The remaining proportional brakes are then applied to smoothly decelerate the conveyor. Johnson Brakes based in Vancouver provided the brakes for this conveyor. The conveyor has an installed power of 7 x 1,500 kW motors, or a total of 10,500 kW. The final drive configuration uses 2,500 mm drive pulley diameters with the head and tail layouts.
In June of 2016 the conveyor system was successfully wet commissioned. At that time AC-Tek obtained a full set of field measurements on the conveyor. However, prior to these measurements the client contracted Sandvik & AC-Tek to provide them with a path to increase the tonnage from the initial 19,200 t / h to 21,000 t / h.
By obtaining a full set of measurements on the conveyor, AC-Tek came to the conclusion that the system capacity could be increased with only a change in speed. Furthermore, this speed increase would not require any mechanical modification. Normally either the reducers are replaced, or the drive pulley diameters are increased to accomplish this. On this system however, it was acceptable to simply run the motors over synchronous speed. As such the belt speed was increased to 5.4 m / s.
Over the life of the project, PROK has supplied 381 pulleys and more than 155,000 Flow Formed rollers. The supply was made from 2010 to 2015 to support all conveyors connecting the mine to the beneficiation plant, including the overland conveyor which is the largest in capacity in Brazil. PROK is also supplying a number of pulleys and rollers to the new conveyor as well.
IM understands that the new duplicate conveyor is being supplied by Chinese company Shanghai Keda Heavy Industry Group Co Ltd( KDHI) which was established in 1993 as a private technology company dedicated to the development of most advanced equipment and heavy equipment manufacturing for bulk material handling systems. KDHI has four factories, with a total area of 345,800 m 2 and a construction area of 252,000 m 2. This will be by some margin the largest and highest capacity large overland conveyor delivered by a Chinese group outside of China.
Other major Chinese conveyor suppliers include China Huadian through subsidiary Huadian Heavy Industries, which recently signed a contract with coal mining major PT Sembada Makmir Sejahtera in Indonesia which includes two long distance coal conveyors- the project is expected to be commissioned in 2027. A third company ZGCMC, has a new cooperation with Huawei on AI based conveyor monitoring.
International Mining | FEBRUARY 2025