Issue link: https://www.e-digitaleditions.com/i/1355344
April 2021 / 29 The dual-skid system design made power connections somewhat challenging. To allow for easier system connect and disconnect, the supplier provided UL-approved control panels to be installed at each facility, along with power and signal cables and equipment to connect the skids to the control panels. "Bulk bag unloaders and eductor systems aren't new, but building a portable one was a first for us," Giacobbe says. PBE For further reading Find more information on this topic in articles listed under "Bags" and "Loading, unloading" in the article archive on PBE's website, www. powderbulk.com. Vibra Screw Totowa, NJ 973-256-7410 www.vibrascrew.com A review of the capacity of the utility's existing silo bin vent dust collectors and fans revealed that the system could handle the con- veying air volumes, and the dust collectors and fans were deemed as more than adequate to handle the dilute-phase pneumatic conveying system's eductor blower volume. The supplier designed the sys- tem to sit on two interlocking skids, one for the bulk bag unloader and eductor and one for the PD blower. Placing the system on two skids makes transporting it and moving it into place much easier. Once in place, the two skids are temporarily linked together for stability during operation. The 4-inch blower hose is then connected to the venturi eductor, and the discharge hose is connected to the silo's pneumatic conveying line. shipment. The system also needed to prevent the hazardous fluorosil- icate powder from leaking during unloading to protect operators and other personnel. The supplier recommended a model I-VHD bulk bag unloader as the best solution for the project due to its low profile. To load the fluoride into the system, a forklift picks up the bulk bag and places it onto the unloader support pan and frame, which holds the bag in posi- tion until the emptying process is complete. With the bag in place, the operator opens the bag spout access door, unties the bag spout, cuts open the inner plastic liner, and closes the access door, preventing leaks and limiting operator expo- sure to the hazardous dust. As the bulk bag rests on the support pan, it vibrates to facilitate material flow into a 4-inch eductor with a 25-horsepower positive- displacement rotary blower. The eductor conveys the material approximately 100 feet at a rate of 2,000 to 3,000 lb/h. All material con- tact surfaces are passivated stain- less steel with polished welds. The utility wound up with a two-skid bag unloading system that could be used at two different facilities. The bulk bag unloader is connected to a 4-inch eductor and uses a positive- displacement rotary blower to move material at a rate of 2,000 to 3,000 lb/h. The new portable, two-skid system connects to the utility's existing pneumatic conveying lines at each facility. "Bulk bag unloaders and eductor systems aren't new, but building a portable one was a first for us."