Hillhead 2014

A gap in the market for such a washing evolution was identified following extensive research, part of which was conducted at the TWS product development forums. This involved TWS engineers and sales technicians working with the global distributor network to formulate the concept.

Central to the development of the new plant was modular design, serviceability and functionality, making it quick and easy to set up and maintain. The plant also includes a range of other innovative features and designs including a web-frame chassis which is easily assembled and complementary to the Aggresand range. The chassis supports the scrubbing hull, the 6ft x 2ft trash dewatering screen, the 12ft x5ft two-deck rinsing and sizing screen, and has an integrated sump and pump. Fully galvanized walkways provide access to all areas of the plant.

In operation, clay-bound aggregate is delivered to a reception chute where the material is flushed with water. The reception chute employs a dead-box design which offers superior wear characteristics. The material is then aggressively scrubbed in the hull by two AR shafts with a spiral of blades and paddles attached.

The design of the shafts causes aggregate to collide with aggregate, ‘rock on rock’, which liberates the clay conglomerates. The liberated clay material discharges through the troughs at the rear of the plant (along with wood, plastic, roots, grass etc) for subsequent dewatering on the 6ft x 2ft dewatering screen, with the light and organic material delivered directly to a skip or stockpiled by conveyor.

Dirty water recovered by the dewatering screen is captured in a rubber-lined pan and piped to the integrated sump below the hull. The hull angle is variable between 9° and 11°, to control the retention time and throughput levels.

TWS offer three choices of blades/paddles including 15mm AR 500, 30mm AR 500 and specifically designed and forged manganese blades. The twin electric motor and gearbox design provides another benefit for customers, comprising two 22kW electric motor and gearbox arrangements for efficient direct drive.

The 12ft x 5ft aggregate screen receives the scrubbed aggregate from the hull. The two-deck screen not only sizes the aggregate, but also rinses off any grit which may still be stuck to the aggregate after scrubbing. The rinsed grit is captured and delivered to the integral sump tank. The two-deck screen, which uses high-quality polyurethane decks to size the aggregate into three stockpiles, employs a compact rolling chute assembly (patent pending) for good access and serviceability.

TWS have developed a cutting-edge but user-friendly control system for the Aggresand plants, which has proved a huge success. The same system has been adapted for the Aggrescrub to give operators levels of automation and control that have not previously been available on wash plants. Using advanced PLC technology, the control system will provide measurement and display of water pressure, pump pressures, motor currents etc. Radio control of all main functions is available as an option, as is remote telemetry, which will allow all data (alarm conditions, run times etc) to be sent to the plant owner remotely, through email or SMS alerts.

Hillhead is the world’s biggest and best show set in real working quarry environment. The show is organised by QMJ Publishing which ran its first quarry show back in 1926 at Llandrindod Wells in Mid Wales.

These days it is presented every two years when it provides showcase for plant, equipment and services for the quarrying, construction and recycling industries. It is supported by 450 leading international exhibitors and in 2012 attracted around 17,000 visitors from no less than 87 different countries. Outdoor stand space is available on the quarry floor and conventional indoor stands, both ‘space only’ and ‘shell scheme’ are available in two large pavilions. Extensive areas are also set aside for working demonstrations of a wide range of plant and equipment.