With continuous asphalt-mixing plants, the first and last few tonnes of every shift are waste.
At least they were. An Ammann team of experts developed a patented solution that ensures all mix has the proper percentage of larger aggregates and fines from the very start to the very end. The creative solution prevents up to 5 tonnes of mix per plant per shift from going into the scrap pile – every day.
How about a fuel source that is not only renewable, but actually reduces carbon dioxide levels?
It’s now in use, thanks to a special asphalt-mixing plant burner that transforms wood dust into a renewable fuel. What makes this Ammann burner even more exceptional is its carbon neutrality. The CO2 released when burning wood is offset by the fact the tree consumed that amount of carbon dioxide during its life. Therefore, this part of the emissions is carbon neutral.
The burner has proven effective and is utilised on a number of Ammann Asphalt-Mixing Plants. It can be retrofitted on existing plants – no matter the manufacturer – as well.
Further improving sustainability is the fact the wood can be locally sourced, saving on the fuel required for its transport.
The RAH100 counterflow dryer is as green as it gets. It enables new asphalt mix to be made with up to 100% RAP.
Essential to the RAH100 is its gentle heating process. RAP must reach its target temperature, but the valuable bitumen will be damaged if the material is heated too quickly.
The RAH100 eliminates that concern. It consists of two connected sections. One is a hot gas generator that contains a burner and forces air toward the second section, which is a counterflow dryer.
The RAP enters at the far end of the counterflow dryer section and moves toward the heat chamber. At the end of the counterflow dryer, RAP is transported to an accompanying silo. The heated RAP mix leaves the dryer before the temperature becomes excessive, so it never reaches the critical temperature where the bitumen is damaged.
There are a variety of recycling solutions for Ammann customers. The RAH100 dryer can produce mix from 100% RAP. The RAH60 is a parallel flow dryer where up to 60% hot recycled materials can be fed. The RAH50 is a middle-ring dryer that incorporates up to 40% recycled materials.
Recycling can also occur at Ammann Asphalt-Mixing Plants that do not employ these specific dryers. Up to 30% cold recycled material can go directly into the mixer, meaning any plant from Ammann is capable of utilising that percentage of RAP.
Ammann has developed asphalt-mixing plants able to burn new, renewable energies – and to even convert waste into fuel.
Biofuels, such as rapeseed and sugar cane, support climate protection and lessen dependency on mineral oil. Tall oil, which is a waste product of sulphate cellulose production, can be used, too.
It’s important to note that Ammann biofuel burners can use more traditional fuels such as natural gas, LPG, light and heavy oil and kerosene. This alleviates the concerns of customers who are hesitant to rely solely on newer fuels – yet are willing to try new approaches.
Biofuel Use Approved for Machines
Hydrotreated Vegetable Oil (HVO), a biofuel made from waste, can be utilised on Ammann rollers and light compactors.
HVO is typically produced from animal fat or processed vegetable oils. It reduces gas CO2 emissions by up to 90% – with no additional costs. Every 1000 litres of standard diesel fuel burned produces ca. 2640 kg of greenhouse gas CO2, compared to just 260 kg of greenhouse gas CO2 for every 1000 litres of HVO burned.
What can be more environmentally friendly than meeting compaction goals – yet eliminating unnecessary passes of the roller?
Ammann Compaction Expert (ACE), a proprietary Intelligent Compaction system, measures and communicates compaction progress in real time. There are several versions of ACE, including one for heavy compactors and another for light equipment.
All provide knowledge that prevents needless compaction, resulting in dramatic reductions in fuel usage, machine wear and emissions.