First published in the February 2017 issue of Quarry Management as Premier Solution
New Metso Premier ES303 screen boosts production and efficiency at Texas sand and gravel plant
A new vibrating screen is getting high marks for productivity, efficiency and maintainability at the Woodlands sand and gravel plant in Conroe, Texas. Before installing the Premier ES303 screen from Metso, the site had been experiencing declining reliability and costly, time-consuming downtime to replace the screen media on its old vibrating equipment.
The new Metso Premier ES303 screen, which has been in operation since early 2015, is running smoothly and helping to boost production and efficiency at the plant, which is owned and operated by Lehigh Hanson Inc. – part of HeidelbergCement and one of North America’s leading aggregates producers with more than 200 aggregates plants in the US.
New solution for screening
The Woodlands plant is situated on the west fork of the San Jacinto river, approximately 40 miles north of Houston, where an electric dredger is used to extract natural sand and gravel. The material is pumped, via a pipeline, from the dredger to the processing plant, where it enters a velocity box/tank that separates the gravel from the sand. The sand is then pumped in below the screen while the clay and gravel are processed through the screen.
‘The gravel goes across the Metso screen,’ said plant manager Jay Jackson, ‘and that’s what we’re using the Metso screen for – the natural, washed gravel.’ The Premier ES303 uses urethane screen media on all three decks. The top deck screens the clay, the middle deck is used for mid-size gravel and the bottom deck is for the extra-fine gravel that drops through the bottom of the screen. The Premier ES303 also features three water spray bars to help remove the clay from the gravel.
The choice of the Metso Premier ES303 vibrating screen was made after Lehigh Hanson identified a need to modernize their production capabilities at the Woodlands plant. To replace the existing 20ft x 6ft inclined screen which had reached the end of its useful life, they required an efficient new screen that would be capable of producing gravel to their particular specifications while reducing maintenance and downtime, as the process of replacing the screen media on the old unit was labour intensive and time-consuming.
As part of a thorough review of vibrating screen brands on the market, Lehigh Hanson contacted Crisp Industries Inc., Metso’s crushing and screening distributor in the state of Texas. They promoted the new Premier ES303 screen to Lehigh Hanson, as this new design of horizontal screens does not rely on shafts timed with gears to create an elliptical motion and therefore has fewer parts to contend with. In addition, when a bearing change is required, the quick change-out of Metso’s MV (modular vibrator) mechanism requires less downtime than a traditional horizontal screen.
Lehigh Hanson felt these were important benefits for their operation. Greg Venghaus, the territory salesman at Crisp who assessed the existing situation at the Woodlands plant and suggested replacing the old incline screen with the ES303, said: ‘They liked the new technology and were willing to be the first to adopt it.’
Enhanced screening efficiency
The Metso Premier ES303 is a high-energy horizontal screen is designed to deliver up to 25% more screening capacity compared with conventional screens of the same size. The two unbalanced shaft lines in the screen rotate in opposite directions, generating a high-energy elliptical motion. This aggressive screening action allows the Premier ES to separate materials with consistency and accuracy, even in damp and sticky conditions.
According to Jay Jackson, the new Premier ES303 screen fitted into the same footprint as the old screen, requiring only minor modifications. ‘We just pulled the old one out and put this one in,’ he said. Crisp Industries provided project management and installation services for the ES303 screen, under the direction of Doug Swoveland, operations manager at the company’s branch in Seguin, Texas.
Although improved reliability and reduced downtime were the primary goals with the new screen, increased production and efficiency were strong factors too. ‘I think it’s done very well,’ said Mr Jackson, ‘it has increased both production and efficiency.’ Chad Miraglia, operations manager at the Woodlands plant, added: ‘With rock and clay, we are probably doing an average of 100 tons/h over it, but I’ve seen it do
160–170 tons/h of rock production at its highest.’
Metso Premier ES screens are also designed for optimal durability and maintainability. Screen media changes are quick and easy. ‘The way we change out screen media is absolutely wonderful,’ said Mr Miraglia. ‘The old unit had the big metal screens that were very difficult to install, and very time-consuming. Now, if we want to make a screen change, it’s very fast and very efficient.’
The new Premier ES303 screen is proving to be a big hit with the entire team at the Woodlands plant. ‘I can tell from my employees’ standpoint that they absolutely love it,’ said Mr Miraglia. ‘They rave about it. In every respect, time saving, cost-effectiveness, it’s above our expectations so far. It does a very good job.’