A real dust-buster: New Schwarze sweeper largest in company's product line; design limits fugitive dust

Diesel Progress North American Edition, August, 2004 by Dawn M. Geske

Schwarze Industries Inc. has introduced its largest A-series regenerative air sweeper for highways, airport runways and construction site sweeping applications. The A9000 sweeper was designed to remove PM 10 (particles less than 10 micrometers in diameter) material with minimal fugitive dust escape.

Reducing the amount of dust disturbed during sweeping is crucial, as fugitive dust particles are the contaminants often found on road and street surfaces. The EPA and other environmental agencies often target these contaminants because they frequently contain a high percentage of heavy metals and other pollutants that run off in stormwater after rainfall and contribute to asthma when airborne.

Schwarze said the A9000 sweeper removes the micron-sized particles by blasting the pavement to create a peeling effect. Air is blasted at an angle across the head width, lifting the debris away from the ground surface. It is then transported across the sweeping head and into the containment hopper through a 14 in. wire-reinforced, molded rubber suction robe. The A9000 sweeper assures debris transfer with minimal dust escape by using a double-belted curtain on the front and rear of the sweeping head to seal it to the pavement.

Powering the 19,750 lb. sweeper is a four-cylinder, 4.5 L, turbo-charged 4045HF275 John Deere PowerTech auxiliary diesel engine rated 140 hp at 2400 rpm. The cleanliness of the engine's air intake is maintained by a two-stage, dry-type Donaldson air filter packaged will a Sy-Klone centrifugal precleaner positioned at the top of the sweeper unit.

The sweeper's 13 gpm Parker Hannifin gear pump is directly driven off the engine and the hydraulic flow is controlled by Bosch Rexroth directional valves. The pump drives Parker hydraulic motors that operate two 44 in. side gutter broom's located on the left and right of the sweeping head. The vertical steel gutter brooms use a free-floating design to follow the contours of pavement and gutters and a spring impact protection system for inward swing when an unmovable object is encountered.

The hydraulic system also includes a 12,500 Btu Thermal Transfer Products cooler that decreases oil temperature, extending the life of the pump, motor, hoses and fluid, the company said.

A 12 V backup hydraulic system raises, lowers and dumps the hopper, opera and closes the hopper door and raises the brooms and sweeper heads without having to power up the engine. Twin hydraulic cylinders are used to dump the 9.6 cu.yd. 10-gauge steel hopper and they are operated by controls located on both the inside and outside of the cab. Inspection doors are located on either side of the hopper and can be opened to load additional debris through, check hopper load or facilitate hopper cleaning.

Schwarze's WhisperWheel Fan System draws The contaminated air in and blasts clean air out using a 10-blade turbine fan. After the debris is drawn in, larger components are then separated by a sawtooth-design separation screen. Smaller particles am separated by the centrifugal force of the fan. Fine dust particles that fit through the separation screen are further removed by the water-based dust suppression system. Water from the 240 gal. suppression system is pressurized by an electrically driven Hypm Corp. pump that incorporates 11 water nozzles located in the sweeping head, near the gutter brooms and inside the hopper.

The A9000 sweeper trait is typically mounted to a standard commercial chassis rather than a purpose built chassis. Using a commercial chassis allows the sweeper to travel at normal highway speeds and allows parts availability at any local commercial chassis distributor, the company said. The sweeper unit can also be mounted on a chassis within the owner's current fleet, reducing costs and training time associated with learning a new vehicle, the company said.

The control panel within the cab has individual illuminated Eaton rocker switches for safety lights, optional controls and each sweeper function. The panel also includes a Faria tachometer, hourmeter and gauges for water temperature and oil pressure.

The Huntsville, Ala., company has been manufacturing sweepers for 30 years and has equipment operating in 35 countries. Its product line includes models designed for park area, industrial, shopping center, airport runway, street and milling sweeping as well as storm water runoff management. Schwarze sells and services its A-series under a dealer network while many other models in its line are sold direct.

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