Construction Equipment Guide
470 Maryland Drive
Fort Washington, PA 19034
800-523-2200
Tue January 20, 2009 - West Edition
As one of the largest suppliers of raw materials for concrete and concrete products in Wyoming, McMurry Ready Mix relies on Metso FS Vibrating Screens for their efficiency and reliability.
“We use all Metso for heavy crushing,” said Pat McMurry equipment manager of McMurry Ready Mix.
“The screens are the key to production in this country. We need something that is efficient. If the machine is too big it is hard to move around from job site to job site,” McMurry said. “We move each crusher plant four to five times each year so that makes the size of the machine and the crushing equipment important. We have five crusher spreads now.”
Metso has thousands of installations worldwide where its screens, feeders and scalpers operate in the most demanding applications, from complete multi-stage plants to highly mobile installations. In 2001, Metso Minerals, a division of Metso, became an even stronger player in the manufacture of vibrating equipment through the merger of Nordberg and Svedala; Metso Minerals now offers more than 300 years of collective experience in vibrating equipment.
Nordberg FS-Series screens are designed to be modular and robust with exceptional performance in a wide range of applications, according to the manufacturer.
The FS series was designed specifically for mobile plant applications but also can be used in fixed applications. The construction is modular with most components being huck-bolted, allowing the screen media support rails, cross members and feedbox to be individually replaced.
The FS Series uses a triple shaftline MV mechanism configuration. The MV mechanisms consist of rotating external counterweights linked via cardan shaft. Each MV shaftline is geared together to produce an elliptical motion with a 45 degree stroke angle.
The angle, size and shape of the elliptical stroke pattern can be easily adjusted. The stroke length can be as long as .78 in. (20 mm). FS-Series screens operate at high “G-Forces” to keep screen media apertures clear and provide accurate sizing at high feed rates.
Each step is completely flat, with no camber or dells to hold back fines. Material is spread evenly over the entire surface, so that every square centimeter of screening area contributes to better performance and more accurate screening, according to information from Metso.
The cascade is generated by the step design that continuously breaks up the layer of feed material so that smaller particles are screened out faster. Stratification is maximized and fines are minimized from step to step, resulting in faster screening, which means that critical sizes are separated more effectively.
McMurry Ready Mix uses three FS Vibrating Screens and has found that its high “G” screens are able to handle almost six “G’s”, making it extremely efficient.
“We have some other screens that won’t hold up at that rate,” McMurry said. “And, if a machine loses a bearing module it can be changed out in four or five hours.”
McMurry also runs three Metso impactors, two 330s and one 400; five 300 cones; and one 400 cone, McMurry says. It is easy to set up the equipment at a new location, even the cones and jaws, McMurry said. “They are well designed.”
McMurry added that they have a 400 Norberg Impactor, which is their primary screen they use for most applications.
“They are very flexible and easy to tune for different applications just by changing the weights,” McMurry said.
“Generally after 10 years on a unit like this it would have a lot of problems, but even with all the hours on it there have been no problems.” McMurry Ready Mix has 300 units with engines, “so the simpler we can make the process to keep things running, the better off we are,” McMurry adds.
McMurry is located in Casper, Wyo., which is about four hours away from its dealer, Westate Machinery in Billings, Mont. The dealer has all the parts 99 percent of the time that are needed to fix the equipment right away, McMurry said.
“Metso is a good company but the dealerships are what makes it work. Westgate Machinery has been exceptional.”