Case studies show how our products perform in different industries and different material clogging problems.
This time it's about the clogging problem when transporting coal at a power plant in Pennsylvania. The power plant in Scrubgrass, Benango County, Pennsylvania uses bituminous waste coal, a mining by-product, to generate electricity. With advanced environmental control technology, we use this coal as a clean energy source. In 2003, Scrubgrass Power Station was having problems with coal handling and was looking for a way to fix clogged chutes.
[problem]
Bituminous coal contains high concentrations of sandstone, clay and moisture. When conveying coal to the hammer mill through a 508mm wide and 1.2m long feed chute, the material jammed and the operator had to stop working. When the hammer mill, or the entire coal handling system, was shut down, workers had to go inside the chute with an air lance and scrape away the stuck material along the walls of the chute. This task occurred 15 times per 12-hour shift and took 20 minutes to complete, leading to process downtime and increased labor costs.
A common air blow system was already installed and blew the blockage through the material, but bituminous coal still accumulated around the 102mm diameter hole. Also, the air blow system about 1m material did not move at all.
[solution]
The company installed two Air Sweep (model VA-51) units on the chute leading to the hammer mill. The condition was that if the air sweep did not solve the blockage problem, the product could be returned. Using factory compressed air, the air sweep unit was set to generate a 0.25 second burst of air every 30 seconds. Air usage per burst was only 1,133 cm3/s, far less than the amount of air required to operate the air blow system.
Each cleverly placed air sweep swept material up to 2.4m in diameter by lifting it off the wall and blowing it away. Mounted so that the two airburst diameters overlapped slightly, the loose material began to flow towards the exit of the chute, facilitating the downward flow of material.
[Results]
The AirSweep ran continuously for a 12 hour shift with no clogging of the chute. According to plant engineer Jeffrey Campbell, the air sweep could be profitable in as little as two weeks. Scrubgrass Power Station has purchased additional units for chutes for the factory perimeter.