Street sweepers have been a familiar sight on city streets for generations. However, most sweepers still use old-fashioned technology to remove dirt from our roadways. They spray water to prevent kicking up excessive dust, and they use rotating brushes to loosen dirt and debris and sweep it into a hopper for subsequent emptying.
The sweepers we normally see are dedicated machines, but many industries use sweeper attachments that connect to some sort of mobile machine, such as a front-end loader. The sweeper attachment uses the loader’s hydraulic system to power the hydraulic motors that rotate the brushes and the hydraulic uses cylinders for positioning. This makes existing hydraulic equipment at construction sites, mines, and municipalities even more versatile by eliminating the expense and additional maintenance associated with operating dedicated sweepers.
This street-cleaning attachment uses a front-end loader’s auxiliary hydraulics not only to power hydraulic motors and cylinders, but also a high-pressure intensifier that produces an atomized mist of water that captures dust for more effective cleaning and cleaner air.
Most of these sweepers, however, suffer the same limitation as the conventional street sweeper: they use a lot of water. Their low-pressure spraying systems distribute water through nozzles that direct water streams just ahead of the rotating brushes. Therein lies the problem. The low-pressure water streams are relatively concentrated, so they contact only a portion of the particles of dust and dirt. The particles impinged on by the water become saturated, which transforms them into a mud-like slurry.
The sweeper in the photo instead uses hydraulics to generate an atomized mist of high-pressure water. The mist is composed of microscopic water droplets that adhere to particles without saturating them. As a result, the sweeper requires a fraction of the water used by conventional machines and cleans surfaces more effectively. Perhaps more importantly, the ambient air is left significantly cleaner. The visibility is better and the air is safer to breathe—even the smell of the dust is eliminated. These qualities are especially beneficial in extremely dusty environments, such as demolition sites and mines.
The key to the technology is a hydraulically powered water intensifier manufactured by Dynaset Oy. Dynaset’s HPW Dust uses a pair of different-sized pistons to amplify pressure of the machine’s hydraulic system to high-pressure water. The HPW intensifier contains no rotating parts and can be used in any machine containing an auxiliary hydraulic system. It comes in power ratings from 10 to 200 kW for generating pressures to 1,600 bar and flows to 300 lpm.
Using high pressure to atomize water into a fine mist is just one use of Dynaset’s HPW intensifier. It can also be used for on-the-spot pressure washing and other applications that benefit from a compact, lightweight source of high-pressure water. It is easy, basically requiring inlet and outlet connections for the hydraulics and the water. Two or more intensifiers can be connected in series or parallel to provide higher pressures or flows, and variable output is achieved by adjusting a flow-control valve in the hydraulic circuit.
Another advantage is that it produces high-pressure water without requiring electricity or a separate gas or diesel engine, making it a safer, more compact, and lower-maintenance alternative.