Building the road to improvement.

In September 2005 Ronez Limited, (Aggregate Industries-Jersey), opened its doors to a brand new 25 metre-high asphalt plant. Manufactured and installed on time in Ronez’s St John quarry by the Danish firm KVM INTERNATIONAL A/S, the finished plant was ready for production within two years of planning permission being granted.

The new plant is the result of much co-operation between KVM and Ronez, and is a state-of-the art plant which is much more fuel-efficient, quieter and more environmentally friendly than the machine it replaces.

With a capacity of up to 120 tons per hour the new plant uses technology and innovations in asphalt and macadam production that were not available when the old asphalt plant was constructed. Using less fuel, it creates less dust, and makes half as much noise as its predecessor, but even more importantly recycles old asphalt that can then be reused on the island’s roads.

Ronez is Jersey’s biggest producer of bituminous macadam, most of which is used by the company’s Road Contracts Division in surfacing the island's roads. With the division playing a major role within Jersey’s infrastructure, the views of the Island’s politicians and public at large have also been taken seriously.

Lee Goulder - Ronez’s General Manager said, “The new plant has received a good response from Jersey residents and politicians, as well as the industry. Every year, tons of waste asphalt is dug up from Jersey’s roads during resurfacing work. The new plant has reduced the environmental impact and enabled the company to provide Jersey’s construction industry with a more efficient and environmentally friendly service”.

The asphalt plant is the latest addition to the St John quarry where as well as an extensive quarrying operation, there is a modern quality-assured concrete batching plant and a computer controlled block-making facility.

PLANT SPECIFICATIONS.

Aggregate material is delivered to the plant which is fed by an 11m³ six-compartment feed hopper, control of the feed into the hoppers is regulated by a 500mm type variable-speed belt feeder; material is then discharged on to the dryer slinger conveyor which feeds the drying plant.

Fitted with a RAP system allowing up to 10% recycled material to be added to the mix the plant comprises of a 2.0 metre diameter insulated dryer running on individually driven polyurethane rollers. Featuring a 9.3 MW gas/oil burner and a double skinned fuel tank the dryer drum can be accessed from both ends for ease of maintenance via a service platform.

The plant is equipped with a 40,000 M³ capacity, low energy consumption KVM type S8-40M bag-filter system with frequency controlled ventilator and a variable fan speed of 37 Kw providing a guaranteed maximum emission of 20 mg/m³.

Heated aggregate discharged from the dryer is delivered to the top of the 2000kg-120tph mixing tower, type Viking 2000H. Delivery by bucket elevator discharges the hot stone into a totally enclosed 1.25 x 4 metres screen. Screened aggregates are then discharged into an insulated six compartment, hot aggregate bin section with continuous level indication and over flow pipes to a hopper. The mixing tower is equipped with four load-cell-mounted scales for aggregate, bitumen and filler, colour pigments and fibre pellets, the latter two being held in two 2.5m³ storage silos.

Additionally, the aggregate and bitumen scales are hanging freely inside an enclosure to eliminate interference from auxiliary exhaust or any other changes in internal/external pressures.

Filler storage is catered for by a 40m³ silo for storage of reclaimed filler, with tanker load out and filler conditioner for disposing of excess filler.
Bitumen storage comprises of two 60m³ vertical electrically heated bitumen tanks with submerged pumps.

Weighed ingredients are dispensed from the various weigh scales into the plants twin-shaft paddle mixer. Once mixed the material is discharged into a horizontal self-propelled variable speed skip for delivery to a 33m³ - 60 tonne mixed material section. This is divided into 2 x 25t and 1 x 10t silos, all operating on one set of load cells positioned below the mixer.
Designed for one-man operation the plant is controlled by a PC/PLC based control and management system type KVM 3000 including an energy programme; with data back-up on to a CD-Rom and “Round the Clock” service assistance via telephone modem to the KVM PC.

Further information:
KVM International A/S,
Industrivej 24,
DK-8620,
Kjellerup,
Denmark.
Tel: +45 87 702 700
Fax: +45 87 702 701
Web: www.kvm.dk