ZB System Improvements

JBW Consulting Engineers completed a project involving a Zinc Borate (ZB) handling system, which is used to move zinc borate from a bag unloader to the users/blenders, that were deemed leaky and maintenance prone. The intent of the project was to replace the currently installed Zinc Borate (ZB) Bag Unloader and its discharge conveyors with new ones.

The current system included one ZB bag unloader which fed both users/blenders, and a hopper located at the bottom discharge of the unloader, where two tubular screw conveyors are pulling ZB. Due to the condition of the system, human contact with ZB was present at the bag unloader, identifying ZB leaks at the bottom bearing of the screw conveyors.

The proposed new bag unloader would be installed at the same location as the existing one, with a new hopper installed underneath, and two new tubular screw conveyors would be pulling ZB out of the hopper. A new local cartridge type dust collector would also create a negative suction into the containment box.

Based on the proposed scope of work, JBW’s work composed of going on-site to verify and investigate the current ZB system, including a concept and iteration review with plant personnel. JBW’s scope included creating overall installation area, general arrangement (GA) drawings for the unloader, conveyor, and baghouse. Installation elevations/sections were provided along with an electrical general arrangement drawing.

Mechanical, Structural, and Electrical scopes of work were also provided per the RFP (request for proposal) project description. This included the new system having a bag unloader with a containment box having the negative suction port connected to a local dedicated cartridge type dust collector, through an automated/actuated isolation valve. The new system also included an electric hoist and trolley, a spring loaded bag support bar, a vibrating inclined hopper, two tubular screw conveyors, and a local control panel with an A-B ControlLogix PLC for the control of the unloader, vibrator, control valves, dust collector and screw conveyors.

Additionally, JBW was able to provide construction administration support, including bid phase RFIs, and on-site assistance as required. With the completion of the project, JBW was able to provide our client with an efficient ZB handling system, that protected its workers from contact with the ZB product.