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Advancing asphalt plant technology

Advances in asphalt plant technology were in major evidence at the bauma 2016 exhibition in Munich - Mike Woof writes One of the most apparent developments at bauma 2016 was the strong focus on asphalt plant technology. The massive physical presence of the asphalt plants could be seen from a distance, right across the showground, particularly the 50m-high machine Benninghoven had opted to exhibit. However, other plant systems from rival firms Ammann, Lintec and Marini, as well as Turkish company E-MAK, c
June 9, 2016 Read time: 13 mins
Amomatic 160 CM plant
Amomatic has designed its 160 CM plant to be versatile
Advances in asphalt plant technology were in major evidence at the bauma 2016 exhibition in Munich - Mike Woof writes

One of the most apparent developments at 688 bauma 2016 was the strong focus on asphalt plant technology. The massive physical presence of the asphalt plants could be seen from a distance, right across the showground, particularly the 50m-high machine 167 Benninghoven had opted to exhibit. However, other plant systems from rival firms 6791 Ammann, 1177 Lintec and 273 Marini, as well as Turkish company 208 E-MAK, could also be seen from a distance. And in the road technology sector there were other players unveiling new asphalt plant equipment also, including 8411 Amomatic, 1250 Astec, 8346 Günter Papenburg and 246 Intrame.

One of they key trends in the asphalt plant market is with the refinement of equipment capable of handling recycled materials. There is a strong awareness in the road construction sector that recycled asphalt pavement (RAP) is a valuable commodity and that sending this to landfill is not only wasteful but illogical from an economic viewpoint. The market for asphalt plant equipment able to handle RAP is becoming well developed in Europe and the US, with China also now seeing growth in demand. This has encouraged manufacturers to design new plants that can cope with higher percentages of RAP as well as producing higher quality output. Meanwhile manufacturers have also been working on new mobile solutions as these deliver greater versatility for customers, allowing clients to site plants alongside construction projects. Modular design and the widespread use of pre-assembled components slotted inside standard shipping containers all help to deliver quick commissioning on site. In addition, manufacturers have been
responding to demand from the market for new systems for producing warm-mix type materials, as these help cut fuel bills and emissions. And the latter point is particularly important for plants being sited in urban areas, given the growing awareness of environmental issues by many local authorities.

Switzerland-based Ammann has made a major investment in its product range with new models for 2016 in the shape of its Prime 100, QuickBatch and SolidBatch plants. Mobility is a key design feature of both the Prime 100 and QuickBatch plants.

The Prime 100 is a continuous plant able to deliver 100tonnes/hour and which has all of its main components slotted inside a single standard shipping container. This is the latest addition to the Prime range and is smaller and more mobile than the existing Prime 140, with its 140tonnes/hour capacity. The firm says that the Prime 100 is fast to commission on site with only a minimum of preparation, requiring a connection to a bitumen tank and a power source to make it ready for use.

Meanwhile the QuickBatch plant has been designed for easy, cost-effective transportation and installation as well as high output. Its core components such as the dryer/filter units and mixing tower modules slot into a series of standard shipping containers. In conventional layout it can be carried in nine containers, though additional containers are needed features for extra capabilities such as handling RAP. The new SolidBatch 140 and SolidBatch 180 plants offer capacities of 140tonnes/hour and 180tonnes/hour respectively and are highly standardised. The base models can be fitted with extra features to broaden capabilities such as handling RAP to tailor the units to an application.
Finnish firm Amomatic is also aiming for ease of transport with its new plants that slot into standard shipping containers. This makes a major reduction in transport costs, particularly if the units are being moved long distances by sea or road. The latest addition to the line is the firm’s 160 CM, which offers a throughput of 160tonnes/hour and shares features with

the existing 120 CM, with a capacity of 120tonnes/hour. The firm has supplied one of the 120 CM units to a customer in Norway along narrow rural roads, and with the success of this unit now intends to offer its entire range in this mobile, containerised configuration. Key modifications from the standard for the application include vertical rather than horizontal silos. Amomatic says that it has designed the plant for ease of erection and the firm says that the unit is easy to move if a customer wants to shift production.

Meanwhile US manufacturer Astec continues to refine its asphalt plant technologies with further improvements having been made to its Double Barrel drum dryer/mixer. This proven unit combines the functions of a dryer and a continuous-process mixer and its latest upgrades have further boosted working efficiency. Said to provide customers with a compact and efficient system, the unit is designed to allow aggregate drying inside its inner drum. Mixing of the aggregate with other materials then takes place in the outer chamber of the unit’s stationary shell. The Double Barrel drum can be installed as part of the firm’s mobile and versatile Double Barrel Express plant, which the firm says is capable of producing mix with up to 50% RAP content. This plant has been designed for ease of transport and can be moved to site using just two loads.

As with its rivals Astec is keen to focus on mobility and the firm has also added upgrades to its highly portable Voyager 120 asphalt plant, which has a counterflow drum featuring the firm’s innovative v-flight design. This configuration is said to ensure a greater uniformity of the aggregate inside the drum during drying, providing a better heat transfer, reducing fuel consumption and increasing throughput. The plant has been equipped with a hydraulically driven swing out drag and batcher system that the firm claims can be set up and made ready for use in around 10 minutes.
In addition Astec is also investing in its production facility and has started work on a new manufacturing at its factory in Chattanooga, Tennessee. The 2,302m2 addition to the factory is expected to start operation in September 2016.

Benninghoven is benefiting from being part of the Wirtgen Group, introducing new recycled asphalt pavement (RAP) developments. The firm’s 50m-high BA4000 RPP tower dominated the Wirtgen Group stand and says that its counterflow parallel drum system features a hot gas generator that offers benefits for RAP applications. The new design heats the recycled material in a counterflow cycle and achieves a high material temperature while lowering exhaust gas temperature. The burner is installed separately, as direct firing would damage the RAP and make it unusable. The system produces low CO2 emissions while allowing a higher percentage of hot RAP in the mix than with earlier generation plant designs. The firm claims that this plant can produce mixes with over 90% recycled material, delivering both hot recycled mixes and cold recycled mixes. It has the potential for an additional cold RAP circuit using a separate elevator, with the cold process able to handle up to 40% RAP.

The Turkish company E-MAK is now offering a novel concept that can be used to optimise the throughput of an asphalt plant, while reducing energy usage at the same time. This unit is designed to be fitted into the circuit of an existing plant and can even be used alongside equipment from other suppliers to raise overall plant efficiency. As its name suggests, the new Sandry is designed to dry the sand being used in the mix prior to this entering the main heating drum for the asphalt plant.

The basic idea is that pre-drying the smaller sand fractions being used in the asphalt using an efficient piece of purpose-built equipment, this can reduce the overall quantity of fuel the plant needs to produce each tonne of mix. Pre-heating these smaller sand fractions allows for a better flow rate through the main aggregate drying drum.

The Sandry has been designed to focus on drying the 0-5mm sand fractions as these have the greatest surface area and typically retain the highest moisture content. Within a conventional system, all the fractions pass through the same route from the storage hoppers to the dryer drum. However the new Sandry ensures that the 0-5mm grain sizes take a longer route through the system, minimising the moisture levels before this material reaches the main dryer drum.

Meanwhile the 0-5mm feed material is routed into a hopper at the top of the Sandry, and is then tipped in metred quantities onto the array of internal shelves, arranged one on top of another inside the tower. These shelves tip in turn at timed intervals onto the next set of shelves down in the Sandry’s tower. This process retains the sand inside the highly fuel-efficient tower and ensures that the material is dried before it reaches the main dryer drum. The tower is kept at a constant temperature of 100°C by twin burners and as the sand does not contain bitumen at this stage, the burners are able to deliver direct heating. Once they have passed through the tower, the dried 0-5mm fractions then collect in a hopper at the bottom of the Sandry, and then mix with the 5-38mm fractions at the entrance to the dryer drum.
Because the 0-5mm fractions are preheated and dried in the fuel-efficient tower, this reduces the heating required for the dryer drum, as well as helping to optimise material flow and this is said to allow the plant to achieve its optimum capacity. E-MAK’s parent company is the Simge Group, which has its own large quarry operation in Turkey and the system has already been tested in a full production environment at this site.

The Fayat Group meanwhile has been busy designing an array of asphalt plant systems, offering features such as mobility, high throughput or to meet the needs of customers in developing markets.

The RM120 ALLROAD plant from Fayat’s Marini-Ermont business is a versatile unit that is said to be easy to transport and commission. The plant can handle up to 40% recycled feed as well as being capable of producing high-quality, hot-mix or warm-mix asphalt, while its output ranges from 50-120tonnes/hour. The plant is equipped with the firm’s RETROFLUX counterflow technology and is designed to meet the needs of a wide range of markets. This single-unit plant is built on a modular concept and can be upgraded at a later date with a range of additional features.

Marini’s mobile XPRESS 2500 plant is said to be highly mobile and can be relocated quickly and easily from site to site. This plant can be used to mix up to 25% RAP into the feed and is trailer mounted, with its mixing tower, dryer, filter and cold feeders all coming on separate units. Customers can specify a trailer-mounted, storage bin as well as a filler unit if required.

The firm’s modular BE Tower meanwhile is designed for customers in markets such as the Middle East, the Balkan nations, Africa and Latin America. It can produce a high-quality mix and is designed to be easy to transport and install. The plant has a small footprint and only requires a flat area of compacted ground to be installed as the units have steel bases and sit on the ground. Fitting into 15 standard shipping containers, the units are pre-cabled and commissioning involves slotting the units together and switching on the power, while bitumen tanks can be sourced from local suppliers. The modular design means that additional components such as a RAP circuit can be added easily if required, allowing the plant to use up to 30% RAP in the feed. It can be used to produce high quality SMA mixes or warm-mix asphalt.

The BE plant has a screening surface of 20.8m2 and is available with a choice of two dryers measuring 1.8m and 2.06m in diameter, both of which are 8.1m long, while it is equipped with a 13.5MW burner. The 2tonne capacity mixer has heavy duty motors and ensures a 160tonne/hour maximum output.

The BE’s control cabin also comes inside a container unit and features two separate air-conditioned areas, while the electrics and electronics have been designed to cope with ambient temperatures as high as 50°C. Operations are controlled by a heavy-duty industrial computer that incorporates self-diagnostics and which can also be upgraded with new software or replaced with a newer model at a later date.
Günter Papenburg has developed a cooling feature for asphalt plants that it says shortens the time normally needed for a plant’s coal dust-fuelled burners to reach operating temperatures. A highly innovative approach to cooling is a key feature, employing patented technology developed originally for liquid-fuelled rockets. The cooling technology has been licenced from German coal milling specialist LOESCHE. The burners are said to be more efficient than rival designs and burn a higher percentage of the coal dust fuel. This allows the plants to deliver asphalt temperatures of 170°C, while producing low emissions.

The technology is already being used in a new asphalt plant in Germany, which is equipped with a counterflow drum and can handle a high percentage of RAP to produce a high-quality mix. A sophisticated computer control package allows the use of different grades and quantities of RAP, as well as adjusting the position of the flights inside the plant in order to control gas flow and optimise operating temperatures. The firm’s range of mobile asphalt batching plants come in standard shipping containers and can be set up in just 1-2 weeks on site.

Products in the firm’s Rapid plant line are available in two basic variants, with outputs of 140tonnes/hour and 180tonnes/hour. Options include hot storage and different hopper configurations. The plants can be supplied with steel frames allowing them to be installed on sites that have only a minimum of preparation, although a concrete base may be required if the customer requests more materials storage capacity.

Spanish firm Intrame has now developed its Nova mixing tower, which offers an output of 280tonnes/hour and features a 4tonne mixer. The firm says that the plant has storage for 160tonnes in its hot bins and that the silos are electrically heated and have steel bases that can be filled with concrete and allow the units to be installed directly onto flat ground, without the need for foundations. The plant can be adapted in various configurations to handle different quantities of RAP as needed by the customer. For a 10% RAP this can be fed into the dryer while with a 30% feed this can be supplied into the mixer or for a 60% RAP feed another dryer drum is also needed.
In addition Intrame has developed its UltraMobile Flowmix plant, which is said to be easy to transport and erect. This is a continuous type plant capable of delivering up to 140tonnes/hour and which has silos that self-erect without the need for a crane.

Although Finnnish firm Kalottikone was not at bauma, the company is keen to highlight its latest designs and also offers a new mobile plant. Its HotMix model is designed to produce up to 240tonnes/hour, with batch sizes of 2-4.5tonnes. The units can be towed onto site separately and are said to be quick and easy to erect without needing a crane, while options include additional silos or components for handling RAP. The firm adds that its HotMix unit also has a low height of less than 10m, making it easier to maintain.

LINTEC says that its CSD 1200 asphalt plant is versatile and mobile as it comes in standard shipping containers. A key operating feature is the patented screen drum technology, said to reduce energy consumption by 15%. Other advantages include easy maintenance and a highly advanced control system allows the operator to make a wide array of mixes. As with other LINTEC plants, the basic CSD 1200 system can be extended with an array of hot storage and recycling solutions (RAP).

Customers can select either a twin-chamber external hot storage silo with a capacity of 100tonnes or a four-chamber version with a capacity of 270tonnes. The company can also install its efficient asphalt burners (LAB series), with ratings from 6-24MW. High efficiency is claimed due to electronically controlled combustion, as well as low emissions and high safety standards. They are available for light oil, heavy oil and gas or fuel combinations, while single fuel burners can be retrofitted for dual fuel use.

LINTEC’s new LEP 95 system is a new, patented warm-mix asphalt solution. This can be configured to produce both hot- and warm-mix asphalt depending on demand at the job site. A major reduction in energy consumption and emissions can be achieved by the LINTEC system working in a temperature range of 95°C-100°C. This unit can be fitted to new or existing plants and is said to produce a smooth and stable foam for an optimum mixing result at low temperatures, while it is reliable and has low maintenance needs.

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