Bulk Bag Discharge Frame
A bulk bag discharge frame can range from a simple stand to a menagerie of features. A bulk bag is hung from a spider and has to be placed into the stand either manually with a fork truck or with a hoist and trolley. Once the bulk bag is in position, the discharge spout is connected to some type of untie box or clamping system. This holds the spout as well as forms a dust tight seal while discharging the bulk bag. Since a bulk bag has been shipped and stored, typically some type of flow aid is required to move the material out of the bag into the discharge spout. Pneumatically actuated massage paddles or plates can be used to assist in product flow. A shutoff device, such as an iris valve, is used to allow the material to start flowing once the discharge spout has been connected to the system. A bulk bag frame can be placed on load cells to act as a control device or for inventory purposes. Finally, a bulk bag can discharge into a storage or process vessel, or into a feed device or conveyor.
Bulk bags that contain hygroscopic or compressible materials may be very difficult to discharge when needed. A bulk bag conditioner applies a great symmetrical force onto each side of the bag in order to break up the contents of the bulk bag. A bulk bag conditioner typically has a turntable on a scissors lift in order to apply these forces to all sides of the bag as well as at different heights of the bag. Typically this force is applied with hydraulic cylinders and the system is operated with a PLC in order to thoroughly condition the bag safely and consistently.