Much like the changing seasons, a Latin American mining site implements four scheduled maintenance outages to keep its operation running at peak performance. With this fore planning, the mine operators began to consider how they could decrease their maintenance time in the concentrator area. One obvious way was to improve the handling of its GIW® MDX-750 pump. They decided to work directly with the source to make it happen.
Challenge
At each scheduled maintenance, the customer would remove the bare shaft pump using a crane, service the pump, and re-install it. The first challenge the customer faced was the pump maintenance time and the absence of an operating pump while the MDX-750 was being serviced. The second challenge involved the movement of the pump into the service bay. The customer only had one crane at the site which was also used to complete other tasks during the scheduled downtime. This caused a delay and lag in the completion time of the pump service. Not to mention, using the crane alone made moving the entire bare shaft risky and unsafe.
To reduce the risk of damage to the pump or injury to personnel, the wear parts (suction liner, casing, hub liner, and impeller) had to each be removed separately. The customer also faced a third challenge - how to safely lift a 50-ton pump, 115 - 131 feet (35 - 40 m) above the bay and 197 feet (60 m) across the mill floor. These challenges greatly extended the time of the maintenance cycle. The customer’s process would take 24 hours to complete resulting in approximately $50K in lost revenue, for each hour that the pump was not operating.
Solution
When hearing of the obstacles faced by the customer and their overall goal, the KSB Mining team reflected on a similar use case at a Chilean mine. Gleaning from lessons learned at that site, the team made two solutions to improve maintenance times. The first was to invest in a spare pump. Replacing the bare shaft pump with a spare pump, while being serviced, would greatly reduce the operating downtime. The second solution offered by the team involved the implementation of a uniquely designed lifting device known as the trapezoidal lifting device. Unlike before, this uniquely designed lifting device makes it possible to remove the entire bare shaft pump into the maintenance bay in one revolution. Each trapezoid’s geometry is tailored to the pump’s center of gravity, using precise chain lengths to ensure a level load every time. This custom approach makes it a perfect solution for the customer.
Results
The investment in and implementation of the spare pump and the trapezoidal lifting device improved the overall efficiency of the site in several ways:
- Maintenance cycle reduced from 24 hours to 6 - 8 hours.
- Maintenance cycle costs reduced from approximately 1.2M to 400K.
- Spare pump purchased to use as a replacement while the bare shaft pump is being maintained, which increased uptime.
- Trapezoidal lifting device instated to move the entire bare shaft pump, as well as the spare pump making maintenance faster and safer.
Product
Lifting Device:
- Steel component installed between the crane hook and the part to be lifted.
- Designed for the orientation, weight, and center of gravity for each family of parts.
- Below-the-hook lifting devices are governed by specifications issued by the American Society of Mechanical Engineers (ASME) and American Welding Society (AWS).
GIW lifting devices are used for a variety of parts including:
- Closed and open shroud impellers
- Pump assemblies
- Wet ends
- Casings
- Suction plate/liners
- Hub liners
- Shaft Sleeves