Ways To Avoid Bridging in Dust Collection Hoppers
Ideally, your dust collection hoppers should be a smooth, unobstructed pathway for the dust to travel through. Unfortunately, dust passing through a small discharge opening can sometimes create a blockage in the outlet. When dust builds up over the opening of the hopper outlet, it’s commonly referred to as “bridging.”
The issue with bridging is that it leads to dust building up in the hopper itself instead of safely exiting through the outlet. To help you avoid this costly hazard, let’s break down some of the best ways to avoid bridging in dust collection hoppers.
Get To Know Your Dust
As we touched on above, certain types of dust can begin bridging due to an improperly designed discharge opening. This is why the best way to prevent bridging is by doing a deep dive into the characteristics of your dust. If there’s a potential for excessive clinging of the dust particles during discharge, consider opting for a larger discharge opening to accommodate.
Likewise, learning the angle of repose for dust particles should also influence your hopper design choices. When speaking with a vendor for your equipment, discuss how the hopper can be steep enough to accommodate your dust’s angle of repose.
By learning that angle and designing the hopper around it, you can promote a smooth flow instead of creating an immense build-up. For these reasons and more, we at DoverMEI design each dust collector machine to meet your specific conditions.
Look for Leaks in Your Airlock
A rotary airlock valve is a dust collector component that sits between the hopper discharge opening and bin. In some cases, you might have it between the discharge opening and a conveyor instead. Either way, it works as an air seal for the discharge opening.
One form of maintenance rotary airlock valves require is regular inspection for any signs of wear on the valve and rotor blades. If you allow these components to wear down, they can cause air leaks in the hopper discharge opening. The moisture created by these air leaks can cause dust to cling together and create a bridge.
Similar to the discharge opening size, you should also be mindful of your rotary airlock valve size. If the valve isn’t properly sized to match the rate and volume at which dust is passing through it, this can also cause bridging to occur.
Mind Your Moisture Build-Up
One of the best ways to avoid bridging in dust collection hoppers is being mindful of how and when moisture can accumulate inside. As mentioned in the previous point, air leaks from the rotary airlock valve can cause moisture to cause chaos in hoppers, but that’s not the only culprit.
Temperature fluctuations can lead to dust interacting with the hopper in a way that promotes clinging of the particles, causing a bridge to form. This is why your dust collector should have a good exhaust fan on it.
Especially in cold environments, allow the exhaust fan to run for a bit prior to letting the dust enter the hopper, as well as after you stop dust from entering. This simple routine can prevent moisture and condensation from building up and causing bridges to form inside the hopper.