International Dredging Review

International Dredging Review

Metso Minerals- Thomas Dredge Pumps experienced a strong performance in the sales of dredge pump assemblies and spare parts in its Thomas Simplicity and Marathon pump lines during the year 2004. Based on dollar volume Metso Minerals had a record year in new pump installation and water end conversions of dredge pumps in sizes eight-inch to 27.5 inch.

Metso Minerals offers standard pumps in the Thomas Simplicity line of dredge and slurry pumps from six-inch to 24-inch. The Thomas Marathon pump line added in 2003 offers standard pumps in sizes 10-inch to 16-inch. Both pump lines are offered as complete pump assemblies or as |!|wet end|!| conversions.

High energy costs have forced all dredge operators to consider new ways to increase efficiency and production. Coupled with deeper aggregate and mineral deposits dredge builders and pump designers have engineered innovative methods to achieve these goals.

A high percentage of Metso Thomas Simplicity and Marathon pumps supplied in 2004 were designed to be installed on the dredge ladder and operated underwater. The ability to double production rates by raising the solids content of the slurry to 32 to 38 percent by weight makes the underwater pump a must for deposits being dredged from water depths of over 35 feet.

For dredge operators lacking the dredge structure to add an underwater pump to the ladder the Hydra-Jet is a popular method of increasing production by injecting high pressure water into the suction pipe and passing it through a venture which creates a negative pressure and increases the effective vacuum. By increasing the effective vacuum with an underwater mounted pump or Hydra-Jet the percent solids carried in the suction pipe up to the dredge pump is increased and therefore higher production is achieved.

Metso pump engineers have designed two new pumps going into service in 2005.

The Z700-1850 pump (27.5-inch x 31.5-inch x 73-inch impeller) was designed and built for a third party customer and destined for a hopper dredge application requiring 60000gpm. All wear parts were made from Metso’s family of high chrome white irons. The MATRI-X MA-54 (20-inch x 20-inch x 54-inch) has been designed and is being built for the hydro transport of mining slurries in mill discharge and matrix lines. Future offerings in the hydro transport pump line include the MA-60 and the MA-64. Wear parts for Metso pumps are offered from both high chrome iron and manganese steel depending on the characteristics of the slurry and the customer’s preference.