F
STORAGE
Dust control system maintenance and troubleshooting
D
by Alex Kice, KICE Industries, USA ust explosions in the grain and milling industries usually start inside process equipment such as mills, dryers, mixers, classifiers, conveyors, storage silos and hoppers. Dust explosions can cause catastrophic loss of life, injuries, and destruction of facilities and assets.
Maintaining the solution
An important item that affects the continued performance of a dust control system is proper maintenance. When it comes to maintenance, dust control systems are often overlooked and ignored. If a piece of machinery (such as a conveyor) goes down, the whole operation is interrupted. Such a disruption cannot be ignored and requires immediate attention. However, if a dust control duct gets plugged with material, it is often not even noticed since the suction will often progressively get worse. Soon, the dust control system is rendered ineffective due to a lack of attention. The solution is to include the dust control system in your planned maintenance program.
Troubleshooting the system
Regularly inspect the system, just as you do with other equipment, to make sure it is operating properly. Check not only the obvious things, such as fan drive belts and bearings, but also check for a plugged cyclone, a worn-out elbow, a plugged-up 78 | March 2020 - Milling and Grain
duct or hood. Many of these problems will affect the amount of suction at the hood. Therefore, by taking an air reading (static pressure) at the hood and comparing it with the reading recorded when the system was originally installed, it can be determined if the system is still functioning properly. This type of reading is simple to take, and the equipment required to do it is inexpensive and easy to use. Some of the items you should think about when troubleshooting a problematic system could include:
Fan function
One of the items you need to double-check is the rotation of your fan in your dust collection system. Is the fan rotation correct and match the manufacturer’s requirement? This is often associated with motor change out. Fans that are turning the incorrect direction will still move some air but will not overcome nearly as much static as it is intended to.
Cleaning systems
Carefully examine your baghouse cleaning system. There are several parts working together for the baghouse filter to function properly. Any faulty item can affect the efficiency or operation of your baghouse. A magnehelic gauge has low pressure and highpressure port connection to the filter housing to measure internal pressure differential. This gauge will read 0” – 10” w.c.. when the pressure drop reaches 6” w.c. new bags should be ordered, then changed when the baghouse reaches 8” w.c. As pressure drop increases, the fan damper should be opened more to maintain airflow.