Aquajet Systems of Sweden says that its revolutionary power pack can address the concerns of noise disruption in hydrodemolition jobs in town centre operations and that of rising fuel costs.

“Escalating fuel prices and concerns about emissions are driving the need for ever more efficient plant,” says a spokesman for the manufacturer.
Aquajet Systems AB has tackled both aspects with the new power pack that represents a significant advance for the sector and can be used for anything from scarifying to deep concrete removal. The Ecosilence Power Pack’s noise levels are similar to those of a normal conversation and it can easily save 30l/hr in fuel.
Noise is one of the greatest challenges in the hydrodemolition sector and contractors are keen to find quieter power packs to avoid complaints from clients and the public. The new power pack is the result of a project that Aquajet started three years ago to meet the challenge of engineering and designing a completely new system with noise levels at least 10dB less than conventional models.
A reduction of 10dB is recognised by the human ear as being half as loud – and the values from Ecosilence are even better than the original target, says the spokesman.
At 66.5dB, the noise from the new power pack represents a dramatic improvement in the sound levels that people will experience. In contrast, conventional power packs create higher noise levels of between 78dB and 82dB, depending on the manufacturer and the type of application. These levels – which can be compared to the noise from traffic or a motorcycle – can be a considerable problem when carrying out urban projects close to residential and office areas.
Use of the Ecosilence Power Pack also achieves a substantial reduction in fuel consumption over conventional designs, saving an estimated €35,000 ($51,310) a year in typical operation. While traditional power packs use between 105 l/hr and 120 l/hr of fuel and consumption, Ecosilence has reduced consumption to just 70 l/hr when producing 189 l/min at 1000 bar at 73 per cent of full power.
“Aquajet’s engineers have addressed all aspects of power pack design and manufacture,” says the spokesman. “Many engineering and design innovations have been combined, such as a 40 per cent increase in sound insulation, including the provision of tailor-made seals for all doors and hatches to block noise propagation. Wall construction has also been enhanced, with an acoustic surface treatment and sound-absorbing insulation to reduce noise and vibrations.”
The power packs purpose-built steel enclosure features two hydraulically-operated hatches for the engine compartment, enabling the operator to vent any excess hot air between operations.
Ecosilence uses an advanced heat exchange system in place of traditional cooling and its exhaust silencer also incorporates new criteria, with every aspect rigorously considered.
The system’s design features a new vibration dampener as well as pipes, hoses and tubing that have all been refined and improved in line with the new design approach.
The choice of a Volvo Penta marine diesel engine was an important aspect of the development. The engine had to combine power and durability while meeting all of Aquajet’s requirements in terms of flexibility, quality and performance. A key factor was its very high torque range from 1100 rpm up to 1800 rpm, which means that the operator never needs to use more energy or power than the task requires.
This type of marine engine was also found to be particularly suitable for the application, thanks to its low noise characteristics. Fuel efficiency was another crucial aspect in today’s operating environment.
The high pressure water output is from a 700 hp plunger pump, which gives good performance even at 1280 rpm. Its output of 189 l/min of water at 1000 bar achieves a respectable production rate for concrete removal, with exceptionally low fuel consumption of just 70 l/hr.
This can mean a saving of 30 litres of diesel an hour compared to a conventional system, which can equate to a financial saving of €35,000 during an 800 working hour year.
“Water flow and pressure can be tailored to suit the application in hand,” explains the spokesman. “A water output of 181 l/min at 500 bar uses just 40 l/hr of fuel. The Ecosilence can be used to provide up to 261 l/min at 1000 bar utilising only 85 per cent engine power output.”
Aquajet has also included features to offer flexibility in transportation and maintenance of the 12,800 kg Ecosilence Power Pack. The 2.8 m high by 7 m long unit can be delivered either with a roll-off frame for transportation by truck, or can be truck-mounted with ISO container corners.
The Power Pack also includes workshop space, to accommodate a workbench, spare parts and accessories.