Urban Demolition Project Uses Atomized Mist to Comply With Dust Regulations
Published: 9/12, 2019
Colorado Cleanup Corporation (CCC) used two BossTek atomized misting cannons to control dust created by the takedown of the University of Colorado’s 8-story Biomedical Research building and the University of Colorado Health Sciences Center, both located in the middle of a well-populated Denver neighborhood with zero air quality complaints.
Out of the 2.5 million ft2 (232,000 m2) of land containing 13 structures, only one had steel construction, and the rest were poured-in-place concrete. Thus, CCC employed several different types of machinery, from standard excavators to high reach excavators with hydraulic attachments. The entire system required CCC to remain compliant with the strict regulations of allowable particulate emissions and control wastewater runoff as mandated by the State of Colorado and further restrictions specified by the municipal permit.
“The two areas in the process that create the most dust are where the concrete breaks and the point of impact with the ground,” explains CCC sr. project manager Chris Formanek. “Large and small chunks of debris would fall into the safety zone, which kicked up a lot of dust. Also, every time the processor uses hydraulic pressure to break the concrete, it creates a plume of dust. This usually happens high up, so the particles can travel pretty far. We needed a method that effectively controlled dust in both of these areas.”
Formanek cited the BossTek DB-60 misting cannons as a key to the project’s success. Either mounted on a roadworthy mobile carriage or a heavy-duty metal skid, the DB-60 has a specialized open-ended barrel design with a powerful 25-hp (18.6-kW) industrial fan on one side and a misting ring on the other. A 10-hp (7.5-kW) booster pump sends pressurized water through a circular manifold fitted with atomizing nozzles. The nozzles fracture the water into an engineered mist that throws millions of tiny droplets in a 200-ft long (60-m) cone.
The mist can be directed at a specific activity or fanned out over a large area using the 359º oscillator, which allows the machine to cover approximately 125,000 ft2 (11,613 m2) in calm conditions. Powered by a 44.7-hp (60-kW) diesel generator set, the machine’s functions are controlled either via digital touch screen display mounted on the unit, by remote hand-held device or by PLC. This makes it easy to be adjusted by workers on the ground or even by excavator operators.
The DB-60 uses as little as 12 gallons/min (45.4 liters/min), depending on the water source, however, CCC had access to municipal hydrants, which provided more volume and pressure. Using a 1.5-in (38.1-mm) cam-and-groove quick disconnect female coupling for the hose, the unit only needs 10 PSI (0.69 bar) delivered to the booster pump. The low PSI requirement allows the machine to be far away from the source, while still providing effective airborne dust control and surface suppression.
With multiple buildings being demolished at once, the two units were shared across the site and placed at critical areas using only a pickup truck or small ground vehicle to move them. During the demolition project, the company received no complaints about fugitive dust caused by standard demolition operations. No dust migration was observed outside of the site boundary, and readings from both the perimeter monitoring machines and the workers’ personal dust monitors registered below required thresholds throughout the project.
“We were impressed by how effectively the DustBoss worked, even high up,” Formanek said. “The versatility is key to our operation, so with a few minutes of set up and adjustment, we essentially just turn it on and walk away.”