Ace Liftaway at Romsey, Hampshire.

09/06/09

DUO Manufacturing has recently completed a project for Ace Liftaway at Romsey, Hampshire.

Designed, manufactured and installed by DUO Manufacturing the new system is designed to handle two types of material, normal skip waste and light commercial waste.

Ace Liftaway, a family operated concern was established in 1988 and quickly grew into an extremely successful business. From a small start of one truck and eight mini skips the waste fleet has since increased to 30 waste vehicles ranging from skip loaders of all sizes, hook loaders, tippers and tipper grabs along with two double drive tractor units pulling injector and walking floor trailers.

In 2002 the company moved from its premises at Braishfield, near Romsey to a new site at Yokesfield Hill Industrial Estate at Belbins, Romsey. With the move the company was able to establish a Waste Recycling Centre where 80% of the skip waste stream could be recycled.

In 2007 Ace Liftaway commissioned DUO Manufacturing (LJH) to design and manufacture a new, larger recycling plant which would enable them to produce sustainable, marketable and consistent products of grit, 20mm/40mm/75mm crushed rubble, 6mm/40mm soil, clean wood, dirty wood, cardboard, non-ferrous and ferrous metals and have the facility of segregating plastic. Blower bay material would be destined for waste to energy.

The development of the new facility would ensure that Ace Liftaway remain an industry leader in waste recycling.

Having purchased the original system from LJH the company had no hesitation in going back to them to order a new system due to the durability, strength and build quality of the previous plant.

The processing system
The new system is operated on separate shifts where pre-sorting of the waste is carried out to remove large and heavy materials. This includes any materials which could block, or damage the plant, or cause injury to the operating staff.

All incoming skip waste is fed onto the system by means of a vibrating feeder which is complete with a heavy duty hopper fitted with bolted mild steel liner plates. The support structure for this arrangement being encapsulated with removable steel plates to prevent any ingress of spillage.

Any lights material is fed into the system through a hopper which in turn delivers material onto a heavy duty belt feeder fitted with a variable speed drive to regulate the feed of material.

From either of the feed stations material is fed to the trommel screen by a feed conveyor, Fitted with a variable speed drive this conveyor can be programmed to run at differing speeds depending on which type of material is currently being processed. Impact bars are fitted at both feed points onto this conveyor.

A six bay trommel, 9.4m long x 3000mm diameter then screens out the - 40mm fraction of the material. This screen has been manufactured to the standard LJH heavy duty design, with removable plate decks. Specifically designed for this system it has been increased in diameter to accommodate the lighter type waste.

The + 40 mm material is then conveyed to the picking station by a belt conveyor (C2) which is similar in design to the feed conveyor, except that this unit is fitted with a fixed speed drive and one picking point on the right hand side. This picking point facilitates removal of any extra large pieces to prevent blockages at the transfer of material from (C2 to C3-picking station).

All material from the picking station belt passes over an air knife at the transfer point to (C3). This device removes a high percentage of light waste from the feed onto the picking station. Air flow is easily controlled by an inverter which can be pre- programmed to suit differing types of feed material.

The picking belt then conveys the material through the picking house. This conveyor has a variable speed drive which is adjustable by a rotary potentiometer switch from either side of the belt. System reset and auto start\stop controls are also included in the remote control units.

Any ‘non-picked' material then passes under an electro magnet to remove the ferrous material which is then discharged into a stocking bay below. A bi-furcated chute with a manually operated diverter gate then distributes the ‘non-picked' waste, either on to a lights waste stockpiling conveyor (when the lights system is operated), or the heavy stone/concrete waste is fed in to a jaw crusher when the heavy skip waste system is operated. An interlock is also fitted to the control on the chute diverter gate mechanism to prevent the light waste system from starting if the gate is open to the crusher feed.

All -40mm material is then collected from under the trommel screen by a steep sided under chute which is fitted with an inspection hatch, suitably sized for entry to carry out routine inspection or maintenance.

A troughed belt conveyor system then feeds the -40 mm material from the trommel to the Binder screening station. This system comprises of a conveyor under the trommel, to a transfer conveyor, which then feeds onto the Bivitec screen feed conveyor.

An overband magnet is fitted over the screen feed conveyor to remove ferrous materials prior to the screen and drop them into a stocking bay.

The Binder Bivitec screen supplied through the DUO-UK dealership is a 4 x 1.6m wide double deck screen which is complete with a 20mm relieving top deck and a 6mm Bivitec type bottom deck to maximise throughput and minimize clogging. Any -6 mm material is then collected from under the Binder screen by a steep sided 6 mm under chute. This chute is again fitted with an inspection hatch suitably sized for entry for routine maintenance.

Material is then fed onto a collection conveyor which is mounted under the screen to feed the - 6mm material onto the stockpiling conveyor.

The - 6mm stockpiling conveyor is fitted with a bi-furcated chute which has an electro-mechanically operated diverter gate, enabling stocking of material into either the -6 mm clean or the -6 mm rubbish bays, depending on the quality of the material. This gate position can be automatically selected as part of the start-up procedure.

Any -40 mm +6mm materials rejected from the Binder screen are conveyed to a further bi-furcated chute which has an electro-mechanically operated diverter gate by means of a troughed belt conveyor. This gate position can also be automatically selected as part of the start up procedure.

The clean - 40 mm +6 mm material is then conveyed to the system for final screening by a troughed belt conveyor, from the bifurcated chute to the crusher discharge belt. Any contaminated -40mm +6mm material is then conveyed to the rubbish stock bay by a troughed belt conveyor.

The system features a crushing station which comprises of a 900 x 600 mm Parker jaw crusher set to produce a -75 mm product. Any crushed material is conveyed to the primary screening station by a troughed belt conveyor. This conveyor also receives the clean -40 mm +6mm product from the Binder screening station.

To maximize the size of the light waste stocking bay a gantry type structure was manufactured to support this conveyor from the edge of the new building to the primary screen station structure. An overband magnet was also fitted over the screen feed conveyor to remove ferrous materials prior to the screen and drop them into a stocking bay.

The primary screening station comprises of a Parker 'Rapide' 5m x 1.8m wide - double deck screen with a 20mm top relieving deck and a 3m long, -10mm bottom deck. All -10 mm material passes through the screen bottom deck into a stocking bay below, with all +10 mm materials passing over a further air knife, to minimize contamination of the final stone products. Any contaminants removed by the air knife will fall into a lights stocking bay below the screen.

The -75 mm +10 mm material is then conveyed to a final sizing screen by a troughed belt conveyor system comprising of a short transfer conveyor from under the screen discharge onto the screen feed conveyor.

The final screening station comprises of a Parker ‘Rapide' 4m x 1.5m wide - double deck screen with a 40mm top and a 20mm bottom deck. This process provides the final product sizes of -75 mm, +40 mm, -40 mm, +20 mm and -20mm + 10 mm which are transferred by chutes into stocking bays below.

The system has proved a great success for Ace Liftaway, Philip Liddell -MD, commented, "DUO Manufacturing's reputation for manufacturing solid build quality and our previous experience of their engineering expertise gave them the edge over their competitors. The new plant has come a long way from our original and the heavy line system works exceptionally well producing continuous and clean recycled aggregate which our customers now trust to be consistent in its quality."

"We are recovering vast amounts of ferrous metal which previously would have slipped through and been landfilled; the wood recovery is giving us a consistent quality and clean product for our customers. The Bivitec Screen has proved a major success working in conjunction with the trommel. We are not only producing a quality 6mm soil we are removing fines from the light waste stream. The benefit of the large trommel is that we do not get blockages due to its large diameter."

"We are also very pleased with the large Picking Station cabin which not only gives our crew a comfortable and a spacious working environment but enables us to remove a large range of products into the 6 bay facility."

The durability of the Parker components has also been successful in producing clean product.

The entire project has cost in excess of £3 million and created a waste centre which runs like a production facility which has already had a significant impact on reducing our landfill dependency, and in return reduced huge landfill costs."