Challenge
A synthetic polymer producer was looking for unique technology that could work in their new production line. This line was going to run custom polymers and compounds. They needed one unit that could handle various materials and production rates.
In addition, the customer previously had a competitor’s brute force spiral and was familiar with basic brute force technology, but unfamiliar with the capabilities of General Kinematics’ Two-Mass design.
Approach
GK educated the customer on the proprietary Two-Mass natural frequency technology vs. brute force technology. Two-Mass would enable closer interface with adjacent transfer equipment, thus reducing overall height requirements by eliminating the transient response associated with brute force drive technology. This spiral would therefore meet the low head room requirements needed in the new production line.
Secondly, GK’s VF wheels reduce the rotating unbalance to minimum setting for startup and shut down eliminating the essential requirements for Plug Stops or DC Brakes. Without such devices, brute force drives produce very pronounced transient displacements during starting and stopping. Interface clearances, and resulting overall height, with brute force drives must be increased significantly to avoid contact with adjacent equipment during a power loss coast down.
Solution
GKC was contracted to engineer a vibratory spiral elevator conveyor incorporating “Multi-Stage Process Air Supply” for their new production line. This unique GK capability enables the customer to rapidly adjust process air flow and temperature at each spiral process stage to optimize production conditions for the multiple polymer formulations to be produced.
The GK Two-Mass natural frequency variable stroke feature enables quick adjustments in conveying rates for optimization of bed depth and residence time in the process stages. Also, the GKC Two-Mass natural frequency technology minimizes the motor starting torque demand resulting in much lower motor power requirements.
Controls, incorporated as an integral part of the spiral operations, alert operators of upset conditions where significant adhesion of the polymer being produced may abruptly occur. The controls automatically maintain the set point peakto peak displacement while issuing a warning to operators to alert them of sticking of the polymer to the spiral flight.
This upset notification allows time for the operators to address polymer sticking while the spiral remains in operation at the set point conditions. Once the issue is addressed, the controls reset and operation continues under normal satisfactory conditions.
Results
Installed Spring 2015, the spiral has lived up to expectations, replacing the competitor’s brute force design. The maintenance department was thrilled to learn that bearing L10 life is typically several hundred thousand hours, extending bearing life considerably. All lubrication is grease, remotely applied during operation, eliminating the maintenance associated with static oil splash. They are putting this to the test now.
Want to learn about GK equipment, or submit a custom engineering request for your special needs? Reach out to our team of GK experts today!
