What is rat holing in powder flow?
Rat holing occurs in hoppers, bins, and intermediate bulk containers when cohesive powders with interlocking particles build up or cake on the walls or sides of the container. This occurs more frequently when powders are discharged using a butterfly valve or slide valve and the powder flow takes place directly above the outlet. This creates a funnel flow effect where the cohesive powders flow directly above the outlet, but eventually build up on the sides reducing or stopping flow and powder discharge all together. This results in increased processing time including container disassembly and cleaning.
What are some solutions for rat holing?
Depending on the frequency of occurrence, operators can use rubber mallets or rods to tap on the sides or inside of the hopper, bin, or intermediate bulk container. If the container is not custom built for this type of manual agitation, it could be damaged or in need of repair after repeated strikes. Stopping production for manual agitation can also cause longer than necessary processing times, further reducing production capacity.
Solve Rat Holing with a Cone Valve
Our intermediate bulk containers, or IBCs, have a center flow bottom discharge design with an integrated cone valve. When the cone valve is lifted, dry bulk solids and powders are discharged in such a way as to avoid rat holing, bridging, and segregation. The cone valve also provides a good level of dust containment because a dust-tight seal is made between the cone valve and actuator when the bin or intermediate bulk container is lowered onto a specially designed IBC discharge system.
Additional features of the cone valve:
- Safe and Sanitary – no parts in the powder flow
- Accurate Dosing – by weight, continuous, and batch
- Low Maintenance – less than twelve components
Watch a demonstration video to learn about these containers with cone valves.
Ask us a question about rat holing solutions or get more information and pricing.
Call: (979) 217-1480