Challenge 1: Bag Connection Process
Most systems need to accommodate a wide range of bag sizes with varying bag spout diameters as well as the amount of spout available for connecting to the transfer module. For high-throughput systems, creating a fast-changeout method may be required to minimize supply shortfalls downstream in the process. Most GMP unloading stations require a dust free transfer and some sort of bag tensioning capability to ensure a completely emptied bag. Addressing these issues while creating an operator friendly and safe mechanical system can be a real challenge.
Challenge 2: Powder Flow
Most Bulk Bag Unloading Stations must be able to handle a wide range of powders, some of which may not flow well. Large agglomerated chunks or ratholing can result in an incomplete powder discharge. Selecting the correct flow aids for a system is an important step in the design process.
Challenge 3: Dust Control
Bulks bags transfer a large quantity of powders in a relatively short amount of time resulting in a lot of displaced air. This creates a lot of process dust that, if not properly managed, can end up leaking around the bag connection. A poorly contained system is a dust explosion hazard and can expose operators to hazardous levels of airborne dust.
Challenge 4: Loss in Weight
Many process designs require control over the net product transferred. Managing product flow to control the loss in weight of the bulk bag can be a challenge, especially for processes with tight weight tolerances. The load cell system, bag tensioning, and product flow control mechanism are critical elements of an effective loss in weight design.
Challenge 5: Partial Bag Unloading
For processes that only call for a partial bag quantity to be transferred, the bag connection and then re-closing of the spout must allow for a re-connection of that same bag on the next iteration. Improperly designed systems can make this nearly impossible to achieve and result in product leaks or spills.
Challenge 6: Integration of Second Order Transfer Receivers
Integrated transfer modules are designed to transfer the powder into a subsequent step in the process. This could be vacuum conveyance, gravity drop, or powder induction into a liquid solution. Each of these methods are effective but can produce unique challenges as you consider the flow characteristics of the powder. Inline pre-processing tools such as de-lumpers, controlled rate feeders, or venturi water falls may be required to ensure a reliable system.
