In order to provide the cleaning necessary to optimize operation of the feeder belt and hopper pits, operations were halted and put into full standby while the work was being performed. The physical conditions of the work area required a confined space entry crew working on a decline of about 35 degrees with aggregate piled three to four feet high and nearly five years of compaction at the bottom and along the sides of the conveyor. The weight and density of the material required extremely powerful, deep vacuum to move the material up the distance and incline it had to travel, approximately 100 feet in total.
Using a powerful liquid ring industrial loader vacuum unit with a 4,100 CFM pump to create deep vacuum, 50 feet of aluminum hard piping was connected at the rear of the truck, down the conveyor system about 65 feet away and a 35 degree angle, to a 6-inch flex hose stinger made of corrugated plastic for flexibility. Utilizing shovels and hand tools, the crew methodically loosened the aggregate at the bottom of the hopper, along the sides of the conveyor system and inside of various small spaces in the surrounding area where aggregate slowly built up over time. The loose material was then fed into the hose for collection inside the vacuum unit. Upon filling the 3,000 gallon tank, an onsite location was used to dump and temporarily store the material for future use.
Over the course of three days, the conveyor belt system, hopper and surrounding work areas were freed of aggregate, allowing the operations to resume safely. An estimated 180 tons of aggregate were loosened, vacuumed, transported, and dumped onsite. The plant resumed operations upon completion.
King-Vac liquid ring industrial loader vacuum truck, confined space entry equipment, aluminum piping, flex hose, hand tools, crew vehicles