A bulk bag batching station can improve batching efficiency and reduce ingredient and handling costs.

Batch size, pounds, min. and max.

• Time to dispense batch, minutes, min. and max.
• Time to dispense batch
• Tamped and untamped ingredient bulk density

A bulk bag batching system is comprised of a bulk bag discharger whose outlet is directly coupled to a feed control device such as a screw feeder or flexible conveyor. The feed device is typically supported by the bulk bag discharger support structure. A microprocessor based batch weigh controller is also included in any system.

There are 3 ways to batch directly from a bulk bag: two loss-in-weight methods and an add weigh method.

Loss-in-weight #1
The first loss-in-weight method, which is the most efficient, is where the entire bulk bag discharging station is weighed and the batch controlled by measuring the weight loss as ingredient is fed into a conveying system or directly into a receptacle (mixer, blender, tank, etc.).

Loss-in-weight #2
The second, more costly, loss-in-weight method requires a separate loss-in-weight feeder complete with refill hopper and refill valve, to be suspended below the discharger outlet.

Add-weigh
The add weigh method involves feeding product from the bulk bag into a weighed receptacle.

Choosing the correct system application for your process requires examination of three main criteria: accuracy, cost and space availability.

A loss-in-weight system where the entire station is weighed is suitable for dispensing batches over 100lbs. in weight with an accuracy of ± 1-2 lbs. and is the least costly of the three configurations.

For batch sizes less than 100lbs. , or for accuracies greater than 1-2 lbs. a loss-in-weight feeder, or add weigh system should be considered. The loss-in-weight screw feeder system will provide the highest possible accuracies approaching ± ?(lbs. or grams), but is the most costly and will require the most headroom of the three configurations.

An add weigh system can achieve very high accuracies based on the volume of the weighed receptacle, and the resolution of its load cells. However, this configuration typically consumes the most floor space as the weighed receptacle must be supported outside of the discharger frame (unless the mixer, blender, tank itself is the weighed receptacle and the discharger feed device dispenses directly into it.)

Note that each of these system types are constrained by a minimum batch dispensing time of 30 seconds. Care must be taken to ensure proper system design to allow switching bags in mid-batch.

For batch sizes of over 100 lbs, Control and Metering offers a screw feeder, or flex conveyor integrated with one of a range of discharger models. The system comes prewired and tested with load cells and batching control panel. It achieves an accuracy of ±1-2 lbs per batch.

Another batching station suitable for food or pharmaceutical applications is provided by the Iso Flo Model, the perfect bulk bag discharging machine for situations where the operator, or the operating environment, must have no contact with the ingredient being discharged. The bag liner is clamped to ensure that no dust escapes from the system. A heavy duty liner tensioner tightens the liner to completely empty the liner of ingredient. Iso Flo with an integrated feeder provides very efficient batching, reducing ingredient and handling costs, and delivers an accuracy of ±1-2 lbs per batch.

Please contact us for further information.

B & H Industrial Products, Inc.
PO Box 68004
Indianapolis, IN 46268
317.872.5806 | 317.875.5649 Fax