QMS washing plants for clean, accurately sized aggregate

QMS washing plants are bespoke, specialised systems used to separate, clean, and size aggregates, producing high quality materials. The washing systems are used in conjunction with the QMS range of SVI and SH screens that have found a real niche in processing raw materials such as sand, gravel, crushed stone, slag, iron ore and recycled concrete. Their primary functions are to separate materials by size, remove impurities, and optimize production efficiency.

The key components include material feeders to deliver raw materials to the plant and evenly distributed using vibrating feeders  for a consistent flow into the screening system. QMS SVI and SH screens separate materials by size while scalping screens provide rapid separation and protect downstream equipment. The screens are fitted with sand washers or fine material washers that remove contaminants using water spray systems. These can be configured as inclined or horizontal, with single, double, triple or quad deck screens.

The SVI-Inclined and SVH-Horizontal Screens drive mechanism consists of two MVU modular vibrators connected with a cardan shaft. These feature advanced dust proof cartridges. The extremely compact and interchangeable units are designed to make maintenance easier compared to a conventional shaft design, with two bearings per vibrator, they also provide exceptional long bearing life.  The vibratory mechanism is located at the centre of gravity, giving circular motion at all points of the screen.

There are three sizes of modular Vibrators available to cover the range of QMS screens. The standard size of the inclined screens ranges from 1.22 to 3.1m in width and 3.6 to 8m in length and are available in one to four deck arrangements. Available in standard and custom sizes, the horizontal screens feature two to four deck configurations, with sizes up to 7 × 2.4m, making them highly versatile for different applications. Bespoke designed screens can also be made to fit into existing structures.

With the inclined screens, the shaft line is positioned at the centre of gravity resulting in a perfect circular motion at all points of the screen. Combined with an adjustable inclination from 12-22°, this circular motion delivers enhanced screening efficiency for all types of applications such as primary, secondary, and final size screening. Adjustable counterweights allow for easy eccentric stroke adjustment to fine tune performance specific to the application requirements. Compared with other circular motion screens, QMS screens provide maximum space between decks. This makes it easier, safer, and more comfortable for operators during maintenance intervals. Screen maintenance is easier as the vibrating mechanism comprises of an alloy steel shaft fitted with grease labyrinth seals and amplitude adjusted by moveable balance weights.

Highlighting the efficiency of its screening and washing plants is the QMS installation at the Cemex Pyford Brook Quary. The Pyford Brook Quarry has been built to produce sand and gravel at a relatively high production rate of 250tph.  The QMS plant provides an initial feed to the grid along the belt feeder consisting of 150mm+ sand and gravel which is then crushed down by a cone crusher before going to a double deck polyurethane primary screen. A double deck washing screen then further processes the material to produce a -20mm product. The final product is then refined to be used in the manufacture of Ready-Mixed Concrete for use on HS2.