Sweepers Work to Eliminate Dust

According to the Environmental Protection Agency, dust pollution from roads has been named the number one cause for air pollution, running out ahead of construction activity and wind erosion. Dust, therefore, is a major issue for street sweepers, and dust suppression is a major focus for street sweeper manufacturers.

PM-10 air regulations originated from the EPA as an air quality monitoring tool. In terms of a sweeper standard, PM-10, which refers to 10 micron in diameter, typically is associated with the California South Coast Air Quality Management District’s (SCAQMD) Rule 1186 concerning low polluting sweepers. While many places may call for PM-10 compliant sweepers, the only place where there is an actual written law defining what this is, is in California. The California Rule 1186 test requires a sweeper to have a maximum PM-10 emissions and a minimum material removal. California developed this test with the input of sweeper manufacturers and environmentalists to help reduce the fugitive dust particulate emitted from sweepers.

Today, across the board, sweepers are PM-10 certified. This has been a requirement since 2005, according to Schwarze Industries’ website, which states, “Government agencies are required to purchase only PM-10-efficient street sweepers. This requirement also applies to the contractors who provide street sweeping services to these agencies.” By 2008, agencies conducting or contracting for routine street sweeping services had to have at least one PM-10-efficient street sweeper placed into service.

Stewart-Amos, for instance, is one company that uses PM-10 certified sweepers exclusively. John Paraschak, Vice-President of Sales and Marketing for Stewart-Amos Equipment Company says, “Vacuum sweepers are great at picking up fine debris. Mechanical broom models are the preferred choice when faced with sweeping a wide variety, size range and large quantities of debris.”

All pickup sweepers have systems to control fugitive dust, which is a byproduct of the process of removing the dust from the surface by either mechanically agitating surface materials or through the entrainment of dust particles by the action of turbulent air. James Crockett, Air Sweeper Product Manager at Elgin Sweeper believes fugitive dust can be troublesome from several standpoints.

He believes that fugitive dust can create a visibility hazard around the sweeper while simultaneously creating a public perception of sweeping ineffectiveness. Fugitive dust can also be a breathing hazard to the operator and to surrounding persons. Fugitive dust may settle on nearby horizontal surfaces such as vehicles and buildings, thus requiring further clean up. Fugitive dust particles can remain airborne and ultimately be considered air pollution. Therefore, the most prominent issue involving fugitive dust, once it has escaped, is that it will not be removed from the environment and will ultimately have to be swept up again.

All sweepers manufactured by Elgin Sweeper have highly developed dust control systems. There are two types of wet systems available on all Elgin products. Crockett says, “Our standard dust control system consists of a water pump and several strategically positioned orifice nozzles. The second type of system is one that has been tested by SCAQMD and has met the Rule 1186. It is important to understand that a SCAQMD system does not necessarily provide better dust control than the standard wet system. It simply means that it has been tested by SCAQMD and found to be compliant with their standards for their particular test criteria for their particular test dust.”

Elgin Sweeper also offers two completely dry dust control systems and one reduced water dust control system. The completely dry systems are available on the Elgin Eagle and the Elgin Pelican using their patented Dry Dust Control System. Crockett explains, “These systems capture the dust with a fan, carrying the airborne dust into the debris hopper where majority of the fugitive dust falls into the hopper, while a small percentage goes to the filter.” The filters are then mechanically cleaned periodically with an on-board cleaning system.

The second dust control type utilizes reduced water and is available on the Elgin Crosswind using our patented Federal Signal VR Filter System. Both the dry and reduced water type systems provide the maximum dust control efficiency and are typically specified for the most dust sensitive areas such as EPA PM-10 and PM-2.5 non attainment areas where pollution needs to removed from the air.

In addition to certain sweepers being optimal for suppressing dust, certain brushes are, as well. Liberty Brush Manufacturing of Shakopee, Minnesota offers a full line of industrial replacement brushes. A highly respected company, they pride themselves on their long term relationships with their customers, as well as consistently exceed industrial standards with their products.

The company’s Double Row (DR) is the most popular brush fill pattern for main sweeping brushes. In this fill pattern, the rows of bristles pick up fine debris while the empty spaces in between the rows trap bulkier litter. The DR pattern is good for picking up both fine and bulky debris. Their Full Fill Brushes are designed for use in applications that have fine debris but not a lot of litter. The dense pattern of these brushes makes them effective for trapping sand and dust.

A large percentage of all dust and road debris rests within a foot or two of a curb. Therefore, curb broom design is critical to a clean sweep. Side brooms, also known as side brushes or curb brooms, have bristles flaring out around the edge of the brush. Side brooms reach into corners and against curbs, throwing debris out in front of the sweeper to be picked up by the main broom. Side Sweep brushes are made of Nylon, Poly and Flat Wire. An added bonus is using a street sweeper equipped with camera systems and dashboard mounted color monitors that provide operators with an unrestricted view of curb side operations ensuring safer and more effective cleaning.

Be it using the right sweeper to keep dust at a minimum or finding the correct sweeper brush to do to the job efficiently, dust suppression is critical to certain facets of the sweeper industry. Focusing on trying to keep dust at bay and minimizing air pollution should be a priority for every street sweeper.

Story by Megan McClure