Bulk Bag Discharger
This is a relatively simple design that requires no moving parts (other than a totally enclosed electric vibrator) that easy and safe to use, excellent at containing dust, and extremely effective at inducing flow.
How A Hopper Style Bulk Bag Discharger Works
- The bulk bag is lowered completely into the hopper.
- The operator opens the hopper access door - at shoulder height - and unties the outer flap and outlet spout tie to enable flow.
- The operator closes the hopper access door and initiates the hopper vibration sequence to induce flow.
Hopper Style Big Bag Unloader Ergonomics and Safety
The entire weight of 
the bulk bag is supported by the hopper and the discharger is designed so that the operator interfaces with its access door at shoulder height
Hopper Style Bulk Bag Discharger Dust Containment
Standard hopper style bulk bag dischargers provide excellent dust containment without having to resort to outlet spout clamps. Three factors provide this level of dust containment performance:
- Dust membrane: As the bulk bag is lowered into the hopper it passes
through and seals with a rubber (or Nitrile in food applications) membrane that seals with the sides of the bulk bag. When the big bag is fully seated in the hopper the membrane has created a sealed enclosure within the hopper. - Hopper outlet: Hopper style bulk bag dischargers are designed such that the bulk bag’s outlet spout protrudes through the circular hopper outlet during discharge. Plus, the diameter of the hopper outlet is slightly less than the outlet spout diameter and that means the bulk bag’s outlet spout seals against hopper’s outlet preventing blowback into the hopper once a flood feed condition has been reached.
- Dust vents: Dual dust vents that can be connected to a vacuum dust
collections system allow the sealed hopper to be maintained at negative pressure. Therefore, any dust particles present in the hopper are extracted. Operators can open the hopper access door during discharge and no dust will escape!
Hopper style bulk bag unloaders feature a simple but effective design that provides outstanding dust containment performance.
Hopper Style Bulk Bag Unloader Flow Inducement
One again, the hopper style bulk bag discharger’s simple design provides excellent performance in this case with flow inducement. Two factors enable flow inducement:
- Hopper shape: When the b bag is seated in the hopper it will have
‘taken’ the shape of the sloped sides of the hopper style b bag unloader. This promotes flow just as the conical bottom does in a bulk hopper. - PULSED vibration: If the product requires further inducement to achieve a steady flood feed state at its outlet, an electromechanical (or pneumatic) vibrator mounted to the hopper provides additional flow inducement. The vibrator’s duty cycle - the amount of time it runs and the amount of time between when it runs e.g. 15 seconds on and 10 seconds off) provides just enough energy to maintain a flood feed condition at the outlet. The vibration amplitude and duty cycle is adjusted during commissioning to ensure consistent inducement.
Hopper Style Bulk Bag Discharger Outlet Spout Clamps
patented a bulk bag outlet spout clamp design in the early 1990s. Within a
few years we realized that while the outlet spout clamp eliminates dust during the onset of ingredient flow and during discharge, dusting would occur when the clamp was lifted and the empty bulk bag was removed from the discharger.
As a result, we designed our Iso Flo hopper style bulk bag discharger that encloses the outlet spout clamp in a negatively pressurized isolation chamber. This design has been effectively used in pharmaceutical plants, food plants and for handing hazardous ingredients.