R.M.S. Ltd. London
RMS had a small washing plant on the site but were looking to significantly increase their production and produce a greater range of products and have zero aggregates going to landfill.
After viewing a number of plants, it was suggested that Tyrone International would be the company to talk to and after consultation and numerous site visits Tyrone International wer eduly awarded the plant contract.
The owner of RMS, commented, “Tyrone took us to a previous installation which we were overly impressed with and on the basis of the build quality and their knowledge we subsequently gave them the contract to supply and install a turnkey solution. “The whole investment is down to the realisation of the opportunities and a way of dealing with a problem by reducing landfill. “Additionally, the installation of the water treatment plant and the press is phenomenal. The whole operation would not work efficiently without it; it works effortlessly ensuring the whole system is in harmony. Absolutely first-class service from Tyrone International , a truly knowledgeable team and the back-up is superb. ”He, added, “We were very impressed right from the start and all the way through the build and now the plant is running weare even more impressed!”
A varied plant feed: The new recycled aggregate washing plant is processing a combination feed of recycled materials containing anything from ‘muckaway’, to utility waste, trommel fines and the quantity of sand and the ratio of the sand/silt fraction completely varies in every bucket load going into the plant. However, the plant has been designed to accept a remarkably diverse feed whilst still retaining through put. Specified to process 120tph the plant is currently achieving an average of 140tph
Commissioned in December 2020, the recycled aggregate washing plant with a full water treatment system and filter press was designed by Tyrone International to fulfil the processing criteria for the material feed. The material is based on an all-in aggregate feed, using a Tyrone International twin-screen scalper which scalps off the +50mm with the -50mm being fed up the primary feed conveyor.
Positive displacement pump to extract the sludge out of the centre of the thickener is then pumped across to a large sludge holding tank where two stirrers keep the silt insuspension. From here a twin centrifugal pump fills the press and when the filter press is full the system automatically switches from the centrifugal pump to a piston pump which uses significantly less energy than the centrifugal pump and contains no wear parts compared to the centrifugal pumphence an exceptionally low operational and maintenance cost. When the water has filtered out of the cakes in the press thenthe pumps will stop and then the press will automatically open and discharge ten cakes at a time.
Crown Aggregates Ltd
Hartshill Quarry has an extensive history in Quarrying dating back to the turn of the century and has been worked extensively until abandoned some years ago with some of the old workings becoming flooded.
Back in 2017, CAL started to roll out their overall strategy for the site, installing a new modular wash plant to process quarry scalpings with a high clay content to produce three aggregates and two sand products.
Fintan McKeever – Director of Tyrone International, commented, “On the Hartshill site silt content in the material is very high at 26-27%, of which the clay content is very high, typically 30% of that silt fraction is clay, or -2-micron size.”
“Initially a centrifuge was employed to produce a manageable cake but the moisture content of the cake from the centrifuge was typically 40-45% moisture. Consequently, CAL ran out of areas on the site to stockpile the cake, therefore by producing a much drier filter cake with the new filter press this has mprovided more avenues to dispose of this material. This has also allowed them to export the cake off their own site and put into other applications off-site.”
“The installation of the new filter press has allowed CAL to produce more tonnage of washed aggregate per day, because the filter press is capable of processing a large volume of sludge.”
“The gloss shine on the cake illustrates the high clay content within the material. To the touch it is tacky with a very high plasticity. “The difference now is that this can be spread on a landfill using a dozer to line and cap a site as the cake produced is impermeable. Additionally, it is being tested for other uses. This material on this site is one of the most difficult materials you can have to filter.”
THE FRACCAROLI & BALZAN OVER BEAM FILTER PRESS
The Fraccaroli & Balzan overhead beam filter press installed at Hartshill Quarry offers so much more than other presses in the marketplace. Fintan gave us the facts. “The Fraccaroli & Balzan overhead beam filter press at Hartshill has 220 – 2 x 2 metre square plates which makes it the largest over beam press installed in the UK Aggregate Recycling Industry! The whole operation from start to finish takes 60-90 minutes to complete the cycle with 8 minutes to clear the plates, which is extremely fast for such a large press.
“The key thing about this press is that the overhead beams sit to the side which allows full access to everything on the top; unlike traditional overhead beams where everything sits in the middle and include a chain drive mechanism and hooks on the chains to open the plates.”
“Eventually all those hooks and the chain wear out and if you get a press ‘blow out’ sludge will cover all the mechanism making it extremely hard to access and maintain everything. On the F&B press, maintenance is super easy as everything sits to the side and there is full access round all sides of the press.”
Fintan, continued, “There is a robot mounted on top of the press which has three functions – it opens ten plates at a time and then shakes them and discharges them into material bays below which other overhead beams don’t do.”
“It also operates the automatic washing system which washes from the top down. This is completely different as alternate systems wash from the bottom up. When it is washing the press, a mobile trolley moves along with the washing system and collects all the water which is returned to the thickener.”
“It’s an extremely fast automated system, we have full remote access to all the control on the plant so if there are any alarms, operator problems or issues we can remotely dial into the plant and can access all the alarms and the history and can then offer advice to the plant operator as to what he needs to action.”
“The whole design philosophy of this plant is making everything as easy as possible, easy to access, easy to maintain, easy to service which has been a total success.”
FULL ACCESS AND CONTROL
At Hartshill Quarry a dedicated press service room situated beneath the press contains all the critical components which protects everything from the weather making it easy to access and maintain.
A press control panel adjacent to the press allows the operator to control the moisture content on the cake by measuring the volume of filtrate water that is coming out of the press. As it gets to a set level the pump will stop and the plates will be discharged.
Fintan, added “Control of the moisture content is done on the initial trials to achieve the perfect product by finding the balance on what is an acceptable moisture content in context to what is an acceptable production.” Access and monitoring for the plant is done remotely. Another added feature is that CCTV has been installed within the press building allowing a 24-hour visual of the press which is accessible from a mobile phone.
“Tyrone took us to a previous installation which we were overly impressed with and on the basis of the build quality and their knowledge we subsequently gave them the contract to supply and install a turnkey solution. The whole investment is down to the realisation of the opportunities and a way of dealing with a problem by reducing landfill. Additionally, the installation of the water treatment plant and the press is phenomenal. The whole operation would notwork efficiently without it; it works effortlessly ensuring the whole system is in harmony. Absolutely first-class service from Tyrone International, a truly knowledgeable team and the back-up is superb.”
Owner of R.M.S. Ltd. London