Mist cannons prevent dust spread during mall demolition

Industrial mist cannons proved critical to the success of a recent mall demolition in Michigan.

The Adamo Group brought in BossTek DustBoss cannons on a large mall demolition involving diverse materials and had zero dust emissions, no complaints and no costly violations. 

Operating since 1964 and headquartered in Detroit, Michigan, the Adamo Group has safely demolished and cleared projects across the region. The company is familiar with the wide variety of materials that can go into construction, and a good example of this was their recent demolition of the Eastland Shopping Center in the town of Harper Woods, Northeast of Detroit. 

Opened in 1957, the Eastland Shopping Center was considered one of J.L. Hudson Company’s most ambitious department store expansion projects, but occupancy began to wane and the property was sold.  

The entire demolition project from start to finish took eight months. Using several pieces of equipment in the fleet, including a mid-sized high-reach crane, front loader, magnetizing machine, etc., the Adamo Group dismantled the structure. An integral part of this was the DustBoss DB-60 misting cannon.  Directed toward the activity area, the fine engineered mist raised the humidity of the area, preventing dust from becoming airborne and travelling into the surrounding community, as well as protecting workers on site from hazardous dust. 

A second DB-60 unit was used to reduce dust emissions from separating, piling, short-term storage, and disruption of the piles while filling transport canisters. “These structures collected over 60 years’ worth of dust, so the separated materials can release a lot of emissions,” said Al Penrod, Equipment Manager of Adamo Group. “The DustBoss really helped us control air quality so we could stay compliant.”

To capture small airborne particles, the droplets need to match the general size of the particles so that they can collide. The combined mass causes them to drop to the ground. Droplets greater than 200µm, like those created by hoses or sprinklers, are large enough to cause a slipstream current to move around them, which actually repels smaller particles and leaving them to remain airborne.  

Automated mist cannons like the DustBoss DB-60 produce droplets approximately 50-200µm from a misting ring in the front which are propelled long distances by a powerful fan that pushes air through the rugged barrel. The droplets offer both airborne and surface suppression using only a fraction of the water required by hoses or sprinklers. They have proven to be more effective, cheaper to run over the long term and require no workers to operate. 

The two DustBoss DB-60 cannons are BossTek’s mid-sized fan-driven designs.  Each cannon is 81 inches (2.06 meters) wide, 117 in. (2.97 m) long, 86 in. (2.19 m) tall and weighs 1,800 lbs. (816.50 kg).  Mounted on roadworthy wheeled carriages, the cannons can easily be moved to where they are needed by a pickup or vehicle equipped with a hitch. 

The units have an adjustable elevation angle from 0-50°, with a throw distance of 200 feet (60 m) of fine mist propelled in a wide cone by a 25 HP fan running at 30,000 CFM (849.50 CMM).  When running with the optional 359° oscillation, each one can cover more than 11,600 square meters (125,000 square feet or roughly 2.8 acres), which is more than 2½ standard American football fields by a single machine. 

The cannons are equipped with a 1-1/2” (38.10 mm) cam-and-groove quick disconnect female hose coupling.  Connected to municipal hydrants with variable pressure, the DB-60s require only 10PSI (0.69 BAR) of constant pressure.  Water passes through an in-line 30 mesh 595 micron filtration system that captures any impurities in the water that might foul the lines.  The water then enters a booster pump where the pressure is increased to the adequate level needed for the 30 specially designed nucleating nozzles attached to a brass mandrel to fracture the water into millions of minuscule droplets.  The use of a booster pump allows the DustBoss to use a fraction of the water of hoses, only up to 26.7 GPM (101 lpm). 

The general rule for demolition dust is to avoid any situation that yields complaints from the public, as complaints regarding air quality submitted to the city or local EPA can trigger an inspection.  Like most of Adamo Group’s projects, no complaints were lodged for the Eastland Shopping Mall demolition. 

The addition of more robust dust suppression means that the company can have two units on large projects or split them between smaller projects as needed.  This ensures that projects can keep operating in adverse conditions where dust may have been a problem in the past. 

“Low maintenance is a standout trait for us.  We position the unit, it turns on every time, and we walk away,” Penrod concluded.  “BossTek has been great to work with and is always there when we need them, but we rarely do.  I would recommend DustBoss to my colleagues.”