Schwarze S-series sweepers use a regenerative air system to accomplish debris pickup. The system is split into two major components. One of these is the forced air or pressure side. The other is called the vacuum, or suction side. Although exact inner workings vary from unit to unit, the following is a general description of how the sweepers operate.
The sweeper unit is powered by an auxiliary engine which is fueled from the truck's main fuel tank. To provide power for the system, the engine propels a fan. The balanced, abrasion-resistant blower fan draws air from within the sweeper's hopper and transfers it to the hopper's inlet hose. This causes a vacuum under the sweeper's pickup head, while at the same time producing an air blast to the pressure side.
On the pressure side, the blower forces air drawn from the hopper down a pressure hose and through an opening in the sweeper head. This air is then funneled across the front of the head. It is transformed into a high-velocity stream that blasts toward the intake.
The sheer force of this air loosens debris, picks it up and pushes it across the front of the sweeper head in a spiraling motion. The debris-laden air is then drawn into the suction inlet on the vacuum side of the head. A series of flexible rubber flaps are installed on the front and back of the sweeping head. These flaps, along with metal skid plates which are on each end of the head, contain the high velocity air within the sweeper head. Due to the vacuum caused by the blower fan, the debris is drawn up through the suction hose and into the hopper.
Once inside the hopper, a number of strategically placed water spray nozzles decrease the amount of air-borne dust. As dust comes into contact with the water spray, it becomes heavy. The dust and debris-laden air slows down due to entering the large volume of the hopper, so heavier objects fall to the hopper bottom. The air is then drawn through a screen in the top of the hopper that removes any remaining lighter objects. Only fine particles of dust remain to be pulled through the screen and into the dust separator in the front of the hopper. The blower fan causes a spiraling action and centrifugal force throws the remaining fine dust against the walls of the separator and it returns through the slots to the hopper bottom. The blower fan then draws the cleaner air from the dust separator back into the blower inlet and the cycle begins again.
