Modern Mining July 2024

Breakdowns, downtime and maintenance The intense demand and stress on the vibrators can be punishing, sometimes causing them to break down. To shut down a single rack translates to a proportional loss in production, so to avoid downtime, operators have the option of recalibrating a single vibrator when backup units are unavailable. In this instance, although production is reduced considerably, the material still passes slowly through the process, releasing considerably less water and putting a tremendous strain on the shaker screen and the single vibrator, reducing their operational life. Maintenance on the unit is a burden, a possible safety concern and repair can take weeks. Weighing more than half a ton, a crane is used to remove the vibrator and load it for transport. Removal requires several employees, and working around unsupported heavy equipment can be hazardous.

Counter-rotating forces With two sets of weights mounted on each end of the motor’s shaft, as the vibrator shaft rotates, the unbalanced mass of the eccentric weights is used to generate centrifugal force. To produce the proper force in a single vibrator, the two sets of weights can be adjusted so they are a mirror image. When synchronising two vibrators, it is important to ensure the vibrators are counter-rotating and that the weights are properly adjusted to the same value. Once mounted to a piece of equipment, any adjustment made to one unit must also be made to the other. Although the function and general design are similar to competitor units, what sets the Martin Engineering designs apart is durability, service life and the fact that Martin is the only US manufacturer that offers a three-year guarantee on its continuous-duty, high-output/low frequency industrial vibrators. Engineered to stay running for long periods under punishing conditions, the

Martin® MM-Series Electric Screen Vibrators use only the highest quality components, such as SKF or FAG bearings with a C4 clearance and Kluber grease. A 10-11 hp (7.5-8.2 kW) motor produces a centrifugal force of 31,000 lbs (14,061 kg). The extended equipment life and reduced maintenance requirements deliver a fast return on investment due to reduced downtime. Results The vibrator was delivered and mounted more than a week faster than expected, bringing the operation up and running to full production. The customer replaced the old units as they broke down with Martin Engineering MM-Series vibrators in two of its plants. Having already installed 10 more units since the initial order, operators were impressed with the quality, service, and long life of the equipment. “The vibrator lasts longer and Martin is more responsive to our needs,” a manager close to the project concluded. 

JULY 2024 | www.modernminingmagazine.co.za  MODERN MINING  37