Published in the May 2006 American Longwall Magazine
“It’s totally specific; we designed everything for in-line full flow longwall application,” said Schroeder senior project leader of marketing Linda Morrow. The name of the product, LW50, even takes on the longwall term along with the unit’s pressure rating of 5,000 PSI.
Developed with its customers to overcome new application obstacles caused by higher pump flows, the patent-pending LW50 can be advantageous for even the largest longwall systems. “Its overall design concept of allowing ‘straight-through’ flow maximizes flow efficiency and minimizes pressure drop,” Morrow said, noting that this single housing lays horizontally in the mine, in line with the flow.
The all-steel housing of the 300-gpm LW50 includes a stainless steel bypass valve that ensures smooth integration with the 95/5 fluid utilized in longwall circuits. Installation of the unit is also designed to be simple, Morrow said: “Porting will be 2-inch BSPP, easily adaptable to Super Stecko fittings commonly used in longwall systems.”
The LW50, usable in all international operations including Australian longwalls, consists of a single housing rather than six housings in parallel and in series – beneficial for several reasons, including the ease of a single element change as opposed to changing elements in multiple housings.
Because the housing is lying flat, Morrow said, gravity is not an issue. Additionally, “many mines have minimal vertical clearances – this is not an issue for a filter housing lying on its side. Also, the lower pressure drop that this overall design provides is another benefit”
Maintenance of the unit is straightforward. The LW50 has a trademarked Dirt Alarm integrated into the housing’s design, allowing mine staff to easily see when the only portion of the unit requiring maintenance – the element – needs to be performed. Optional electrical indicators with MSHA approval in various configurations and signal outputs are available for almost any system.
The LW50 is intended for the user market rather than original equipment manufacturers so the end user, a longwall operation, will be the customer. Morrow added that the unit’s replacement elements are made of a unique proprietary synthetic media designed especially for high flow and 95/5 fluid applications and can endure even the highest of face flow velocities.
Schroeder will offer this element in Beta200 >3um, 5um, 10um, and 15um absolute efficiency options. This level of filtration is required to protect the valves at the shields and is not achievable using alternative wire mesh elements due to their lack of absolute ratings.
While the unit is currently undergoing beta testing at an eastern US operation, Morrow said the entire staff is anxious to officially unveil it at the National Coal Show in Pittsburgh this year. “It’s Schroeder’s answer to mining’s demand for a very specific product.”
The Pennsylvania-based company is confident that the LW50 will be the mines’ desired upgrade to protect the valves on the shields and extend the pilot element’s service life in any longwall operation.
