Velde Pukk AS specialises in quarrying, rock drilling, transport, ready-mixed concrete, asphalt production and laying.
Operating as an environmentally friendly organisation, Velde also undertakes work in coast building and shore protection. Founded in 1984 from a quarry in Sandnes on the southern tip of Norway, the company began by producing aggregates for road and pipe construction.
In 2000 Velde considered higher value applications for its products that led it to establish an asphalt plant in 2006. By 2007 Velde had built one of the world’s largest, modern and eco-friendly production facilities for crushed rock, asphalt and concrete. A year later Velde set up a contracting business for road construction, and in 2009 it completed a huge site for the manufacturing of concrete using crushed rock.
After a visit in 2012 to a CDE Global open week at Sheehan’s CD&E recycling plant in Oxford, UK, Velde realised the significant efficiencies that CDE washing equipment could deliver in terms of the plant’s ability to produce high quality aggregates from waste material on a large capacity.
Velde’s goal was to avoid sending CD&E waste material to landfill and to place the company in a position whereby it could reuse the clean sand and aggregate in a variety of construction projects and ultimately generate cost savings by eliminating landfill taxes. The other aim was to preserve the life of Velde’s landfill site.
“When we saw what was on offer during our visit to the UK, we quickly understood the potential and value in recycling CD&E waste material,” Velde managing director Egil
Velde said.
“Given that we were previously landfilling a significant volume of waste material, we made a decision to enlist the expertise of CDE to provide us with a plant that would produce washed sand and aggregate material, which we in turn could use in other construction projects.
“We are excited about our recent investment and are confident that the CDE plant will deliver a solid return by allowing us to divert waste from landfill going forward.
“We estimate a diversion of 600,000 tonnes of CD&E waste per year as a result of this new washing technology.”
PROJECT DELIVERY
The CD&E recycling plant was installed in 2014 and is now producing two grades of sand: 0-2mm and 2-4mm. A range of washed materials is also being produced in the form of 4-11mm, 11-16mm, 16-22mm, 22-90mm and +90mm aggregates.
Velde is also utilising the dry cake output from the filter press. The dry cake, which contains more than 80 per cent of dry solids content, is being used for the creation of embankments.
{{image2-a:r-w:200}}“This project is one of the largest wet processing recycling plants installed in Europe,” CDE’s regional manager for Europe and Russia Eoin Heron said. “It’s evident that Velde is a hugely progressive company and this latest investment is certainly testament to its continuous innovation and commitment to embracing sustainable technologies.
“The plant will allow it to secure its market leading position in the Norwegian quarrying and construction industries.”
A collaborative approach was employed by CDE to ensure consistent and direct contact was maintained with Velde, and this began at the pre-sales stage. A design workshop was hosted at CDE headquarters, allowing Velde to have a significant level of input into what type of plant would meet and exceed its requirements.
This visit included input from not only the CDE design team but also the electrical department, the technical team, the pre-sales team and the project management team.
Due to the space restrictions on-site, Velde was keen for the project to be delivered as quickly and efficiently as possible, to avoid incurring any extra costs on its part in terms of crane hire and on-site logistics, so timing of delivery to site at each stage in this instance was imperative.
As a result, CDE ensured the most efficient approach was employed in terms of logistics. This reduced the project delivery time by 40 per cent.
Such was the scale of the project and the size of the plant, it involved 55 lorries during the transportation phase to deliver the CD&E waste recycling plant from CDE HQ in Northern Ireland to the Sandnes site in southern Norway.
“Due to the space restrictions on-site, this project posed a number of challenges in the delivery phase,” CDE project manager Colum Bryson said. “Namely, it was to ensure that all install phases ran smoothly with enough space on-site, and ultimately to ensure that Velde did not incur any additional costs.
“As a result, we placed a significant level of resources behind this project and were pleased to deliver, install and commission the plant in almost half the time anticipated.
“Velde had close involvement from the outset and this allowed us to ensure that all of its requirements were met at each individual stage.”
WASH PLANT TECH
The large-scale CD&E waste washing plant comprises many modules. The first is the incorporation of two R2500 scalping units, allowing for the direct feeding, screening and stockpiling of +90mm materials.
Two feed conveyors complete with integrated overband magnets are included, which allow for the removal of any ferrous material prior to the primary screening stage, and belt weighers are also incorporated to enable Velde site operators to monitor the feed rate of material to the plant. Logwasher technology is featured in the process through the installation of two AggMax 151 systems that accommodate the primary screening and high attrition washing of the claybound feed material through a combination of the RotoMax logwasher and high frequency screening technology.
{{image3-a:r-w:200}}At the rear of each AggMax are trash screens and integrated stockpile conveyors, allowing for the removal of lightweight contaminants.
A customised EvoWash 201 sand washing plant is introduced later in the process that features a hydrocyclone, a dewatering screen, a sump and a slurry pump.
This system facilitates highly accurate separation of silts and clays from the final washed 0-2mm sand product and the further screening and dewatering of the 2-4mm product.
Two radial stockpilers are also included, allowing for the stockpiling of material in a circular arc. A P2-108 ProGrade screen has been integrated into the plant following the scrubbing stage carried out by the AggMax logwasher technology.
The ProGrade screen includes two decks and features an inclined circular motion designed to cope with the harshest of conditions. The P2-108 screen, which sizes and washes the aggregate at a feed rate of 350 tph, features a bottom deck split screen.
It can produce four end products for stockpiling, which include 22mm-90mm, 16mm-22mm, 11mm-16mm and 4mm-11mm aggregates.
Within the water treatment phase, an AquaCycle A1500 has been utilised to bring significant cost savings by reducing the volume of fresh water required to feed the plant, a reduction of more than 90 per cent.
With a capacity of 1500m3 per hour, waste water from the washing plant containing all the fine silts and clays enters the de-aeration chamber at the side of the tank. At this point polyelectrolyte is dosed to the waste water from the Flocstation Polyplant. The poly dosing is fully automated via a CDE auto sampling unit designed to eliminate operator intervention. The flow of material into the tank is slowed to help ensure the efficient settling of sludge.
The sludge sinks to the bottom of the tank and the clean water is forced to the top and flows out of the tank over the peripheral weir. The water is then sent to the CDE AquaStore, which acts as a complete water storage and pumping system for the fresh, recycled water.
Filter press technology has also been incorporated in the CD&E waste recycling operation at Velde, with a 2m x 2m overhead beam filter press. This eliminates the requirement for Velde to have settling ponds to store waste water from the plant, while maximising water recycling and reducing health and safety risks on-site.
With restricted space on-site, this was the most appropriate option to manage the water recycling phase.
A SCADA control system has been fitted with a modem that enables CDE to offer remote diagnostic support from its headquarters in Northern Ireland. This is housed within Velde’s site office. It allows for remote monitoring, removing the necessity for an operator to be on-site.
This control system shows elements of the plant that are operational, as well as displaying levels of water and slime.
The operators at Velde have also been provided with hand-held, remote control tablet devices that are programmed to carry out several functions such as remote start/stop of the plant. They also give operators an overview of plant performance and functionality to change various parameters in relation to different elements of plant operation.
Also incorporated on-site is the CDE Optimax, a control automation system that integrates with the plant and assists operatives in monitoring plant productivity.
A digital display screen allows them to easily identify performance at a glance. This intelligent digital technology monitors the loadings within the various aspects of the plant and continually adjusts the feed rate of material in real time, to ensure maximum productivity is always being achieved. The visual display also provides the operator with total tonnage of feed rates, while giving a percentage breakdown of each product type and preventing overloading of material.
The Optimax technology has been proven to effectively increase productivity levels by 20 per cent on recent CDE installations, ensuring operations generate the maximum possible yield.
PREVENTATIVE MAINTENANCE
Following installation of the plant, Velde invested in a CDE CustomCare service contract, in the form of a preventative maintenance program. Velde opted for four comprehensive site visits over an 18-month period by a CDE service engineer, regardless of operating hours or throughput levels. On-site, the engineer undertook a detailed plant audit and compiled a report of plant performance, along with any areas for recommended maintenance, to ensure plant performance remains at the optimum level. Plant recalibrations were also included, if required, and a full history of every service visit could be logged along with outcomes and actions. Regular preventative maintenance inspections have a proven impact on plant capacity and will provide Velde with transparency on expenditure through a fixed cost agreement, while ensuring consistently high quality products.
“By offering our customer regular plant inspections, this allows them to ensure that they’re capitalising on the benefits of increased productivity levels,” CDE Global’s CustomCare manager Martin Jackson said.
“Our approach to preventative maintenance gives the customer a thorough picture of how well their plant is performing, and ultimately saves them money by maximising uptime.
“In this instance, the four regular site visits that Velde opted for have allowed it to generate the best value from its CDE plant through the production of quality end products that demand a high commercial value.”
Velde serves various markets, with the main business stemming from contractors for the building of roads, or trading activities with other concrete and asphalt producers that specialise in roads, walls and piping. It has an annual turnover of 354 million kroner ($AUD55.2 million). For further information about Velde Pukk, visit veldeas.no
Source: CDE Global