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McLanahan Dewatering Screens Continue to Set the Standard

Dewatering Screens are a staple in many industries and the go-to piece of equipment for creating a consistent drip-free product. They offer the highest level of dewatering without the use of a filter, which makes them a cost-effective option. 

History of Dewatering Screens

Dewatering Screens were introduced by VELCO in the 1970s to dewater coal in South Africa. Unlike traditional screens used for sizing and separating, Dewatering Screens were designed to capture all the material on the screen deck, allowing only the excess water to pass through.

In 1980, Linatex brought Dewatering Screens to the United States, where they became very popular in the coal industry. A decade later, dewatering became more common practice in the aggregate industry, and Dewatering Screens soon found a home there as well. 

How Dewatering Screens Work

Dewatering Screens remove excess moisture from partially dewatered material discharged from a Fine Material Screw Washer or Hydrocyclone/Separator™. The material is fed onto the Dewatering Screen’s steep, inclined surface at the feed end to achieve rapid drainage. Two counter-rotating vibratory motors throw the material upward and forward along the screen deck at high G-forces. This motion allows water to detach from the particles. The uphill slope of the screen creates a deep bed of material that allows material finer than the screen openings to be retained and the water to pass through. 

Improving the Design

Although McLanahan Dewatering Screens are based on the original Velco design, McLanahan has made improvements over the years that have enhanced operation and simplified maintenance. McLanahan Dewatering Screens are built with a robust crossbeam structure that can withstand the most extreme applications yet makes the machine easy to maintain.

They also feature heavy-duty screen media with full-length engagement that nearly eliminates material getting in between the urethane sections, which can lead to premature wear. McLanahan Dewatering Screen panels snap into place rather than pin in, which makes them easier to change out when a panel needs to be replaced.

McLanahan Dewatering Screens feature longitudinal dividers on the screen deck to dewater up to three different products on the same screen at one time. The company also pioneered the use of Dewatering Screens in the agricultural industry for removing excess moisture from sand bedding that has been recycled through a Sand Separation System.

In early 2020, McLanahan officially launched a modular, skid-mounted UltraDRY Dewatering Screen complete with sump and pump after numerous successful installations of skid-mounted units. These screens are designed to fit under any brand of sand screw or cyclone and can be moved easily with one pick. The water that drains through the screen media is captured in the sump beneath the screen and can be recirculated back to the screw or pumped to a downstream process.  

The Lowest Moisture

Dewatering Screens typically discharge material at 8-12% moisture, but McLanahan Dewatering Screens have been known to achieve as low as 7% moisture. Removing this excess moisture from a final product ahead of stockpiling allows for quicker sale, less mess under conveyors for improved housekeeping and less water lost to waste for a more sustainable site.

McLanahan Corporation has been providing industry-leading aggregate and mineral processing solutions since 1835. For more information on adding a McLanahan Dewatering Screen to your site, contact sales@mclanahan.com.