Mobile mixing plant design continues on the road of success: Wirtgen KMA 220i with even more output

The powerful KMA 220i convinces in a broad range of applications, offering an outstanding mixing capacity of up to 220 t/h for the production of high-quality cold mixes from recycling construction materials: The mixing performance surpasses even that of many large stationary mixing plants.

The mobile plant design offers easy setup and economically efficient mix production close to the construction site. The KMA 220i is environmentally friendly in every respect: Time-consuming truck transports between mix production and construction site are reduced to a minimum, which has a very positive effect on fuel costs. In addition, the source materials for mix production need neither be dried nor heated, which reduces CO2 emission even further.

The consistent and complete recycling of reclaimed construction material, as well as the resource-saving and cost-effective processing of materials are becoming ever more important in view of continuously rising prices for energy and raw materials. With its mature functionality, the KMA 220i offers construction companies an attractive opportunity to successfully open up the potentials inherent in this line of business.

Compared to its predecessor model KMA 200i, the mixing capacity of the KMA 220i has been increased by 10% to 220 t/h. The plant carries a strong 6-cylinder diesel engine with an output of 129 kW, ensuring an appropriate performance capacity of the mobile mix producer. When operating at a capacity of 200 t/h, for instance, a full truck load of 20 tons of cold recycling mix can be produced every 6 minutes. Continuous production guarantees that even large road pavers, such as the

Vögele Super 2500, are continuously supplied with cold mix. Being equipped with an own engine station, the KMA 220i is independent of external power sources. The engine is accommodated in a soundproof housing, which is beneficial to the environment, and can be switched to an economical ECO mode during non-productive times. Its low emission values permit the plant therefore to be operated also on urban construction sites.

The KMA 220i achieves high daily production rates at a consistently high mix quality. Homogeneous mixing of the construction materials is ensured by a twin-shaft continuous mixer with wear-resistant mixing arms and adjustable mixing blades made from special hard cast iron.

The KMA 220i is capable of producing cold mix either in batch mode or in continuous mode. The mix is then directly loaded into trucks or stockpiled via the plant’s slewing discharge conveyor. Mixes produced with foamed bitumen are particularly suitable for stockpiling as they can be stored over extended periods of time.

Favourable transport dimensions of 13.40 m in length (14.71 m including the cabin), 2.50 m in width and 4 m in height, as well as a total weight of around 29,950 kg enable the KMA 220i to be relocated quickly from one construction site to the next. A special permit is not required as the plant’s transport dimensions adhere to the international guidelines for road traffic. The complete mixing plant is permanently mounted on a low-bed trailer. The plant is transported using a standard tractor vehicle, and is fitted with standardized connections. All that needs to be done is swing in the cement auger, discharge conveyor and operator’s cabin prior to coupling.

The plant does not require a foundation to ensure safe setup. The stable, telescoping front support legs are folded out manually. Hydraulically operated telescoping support legs are mounted below the water tank and between the axles, carrying the plant’s weight. Operator’s cabin, cement auger and discharge conveyor can be positioned hydraulically at the mere push of a button. The clever setup and transport concept of the highly mobile cold recycling mixing plant enables users to save time and money, for example, in terms of additional personnel required for setup.

A clear advantage of the KMA 220i is its versatility in processing different unbound construction materials. With the addition of binding agents, cold mixes of superior quality are produced from a large variety of virgin aggregate mixtures and/or reclaimed recycling materials. Recycling materials suitable for processing include milled material, as well as all materials from the upper road pavement.

The KMA 220i offers a full range of options also with regard to binding agents. Using cement, bitumen emulsion or even foamed bitumen, and adding water in addition to any of these, the mobile plant is capable of processing the source material into a cold mix suitable for use as a bound base layer. Further mixing options include the combined use of cement and bitumen emulsion, or of cement and foamed bitumen. The formula for binding agents and aggregate is determined by preliminary laboratory testing. Using the innovative foamed bitumen is particularly efficient as the quantities to be added are typically very small. Precise weighing and metering of the binding agents is effected via a load cell and microprocessor control.

The cold mixes produced by the KMA 220i are ideal for use on motorways, for high-quality base layers in road and path construction, and for car park and storage areas in industrial estates. Cement, bitumen emulsion and foamed bitumen are the binding agents used for highly stressed road pavements. Cement is used for the production of hydraulically bound base layers. Bitumen emulsion and cement in the construction material mix produce bituminous / hydraulically bound base layers. The use of foamed bitumen and cement results in stable base layers of high flexibility.