Filters for the underground
Published in: Diesel Progress North American Edition
Date: 9/1/2008
Longwall mining is a form of underground mining in which a long wall of coal is sliced from the face of the mine. These longwall panels can extend 10,000 to 13,000 ft. long and are surfaced within the low vertical and horizontal constraints of an underground mine. Based on these confined quarters, underground mining equipment must meet height and width restrictions that often dictate component and option selections for a piece of machinery.
At the MINExpo Show in Las Vegas, Nev., Schroeder Industries, Leetsdale, Pa., will showcase its LW60 longwall hydraulic filter. Aimed at the underground mining market, the LW60 filter incorporates a single filter housing aligned horizontal to the hydraulic fluid supply to better enable a vehicle to clear the vertical restrictions of an underground mine.
Schroeder said it developed the unit to overcome obstacles caused by higher pump flows and to extend the pilot elements’ service life. By creating a horizontal, straight flow-through, the filter is able to obtain maximum efficiency by minimizing pressure drop, Schroeder said.
Construction of the LW60 filter integrates a steel housing and UP to 300 gpm flow capacity. It has a stainless-steel bypass valve intended to ensure smooth integration with 95-5 hydraulic fluid utilized in longwall circuits. The filter is also designed for use in some biodiesel applications.
The LW60 filter’s full flow-through design was engineered to remove contaminants while extending the metal mesh element life. It protects the valves on the longwall shields and has an element change clearance of 34 in. The filter’s porting cap and housing cap are also steel.
The filter media of the LW60 units uses a new proprietary synthetic media, which has been specifically designed for the mining industry, said Schroeder. Referred to as Excellement-MD, the media is offered in 3, 5, 10 and 15 pm absolute efficiency options.
Fluid is supplied to the filter through 2 in. BSPP ports. These, Schroeder said, are easily adaptable to Super Stecko fittings commonly used in underground applications.
A Dirt Alarm has been assembled into the housing of the filter. It provides visual confirmation when the filter element needs to be replaced and has been approved by the Mine Safety and Health Administration (MSHA), Schroeder said.
Maximum operating pressure rating on the LW60 filter is 6000 psi and minimum yield pressure is 18,000 psi. It has an operating temperature range of -20[degrees] to 225[degrees]F. Dimensions of the filter include a 5 in. outside diameter and a 38 in. length. Weight is 550 lb.
Schroeder also offers a nonbypass high crush longwall filter with the LWN60 model. This unit has 4500 psid crush rating and cleanable 25 [micro]m metal mesh element.
The Schroeder filtration family features a range of filters, replacement elements, reservoir accessories and inline and offline filtration products. Its lineup also includes oil service, process filtration and biofuel filtration equipment.