The purpose of the Reagent System Upgrade project at Oaky Creek was to install new reagent storage tanks, discharge / delivery pumping systems and automated flow control distribution manifolds for the delivery of each reagent to the nominated process connections. In the event of failure of the automated flow control system, rotameters for manual reagent addition were included as a contingency.
Orana Engineering performed the mechanical, electrical and control systems design, drafting and engineering for the project. The primary deliverables for the project included scope of works documents, construction drawings, a functional specification document, bill of materials, commissioning & operating spares lists and equipment & instrument data sheets. For a complete collation of project documentation, an operation & maintenance manual and hazardous area dossier were provided on project completion.
A key design consideration for the new system was the location of the reagent storage tanks. One of the existing tanks was located adjacent to the workshop which created issues for hot works due to its flammable classification. By relocating the new tanks to a remote location, safety was improved by eliminating the requirement for procedural control during hot works. The system automation was designed to improve efficiency and production through accurate control of reagent addition to the process. Self-bunded tanks were selected for environmental protection and to eliminate the requirement for a concrete bund around each tank, improving area access and reducing the overall project cost.
Mechanical design included pump & valve selection, pipe manifold design and support frame design for the pump stations and distribution manifolds. The pump stations utilised a duty-standby pump arrangement and in-line filtration with automated pressure sensors to detect blockages. Due to the remote location of the storage tanks, the above ground plastic delivery pipework required a suitable route across site to the process plant with adequate pipe supports and expansion loops. The distribution manifolds required both automated flow control valves and manual rotameters with manual valve switchover. The system also required various pressure control valves for pressure relief and regulation. One storage tank utilised an automated fill configuration based on tank level, while the other storage tank required a remote truck fill point.
Electrical design primarily involved lighting and power to various equipment and instruments including pumps, control valves and sensors. Control system design involved the integration of the system to the DCS to minimise the field control required for process control. Due to the hazardous area classification for both reagents, design and selection of equipment was performed by competent personnel.
Orana Engineering used AutoCAD to produce a drawing set for shop fabrication, general arrangement and installation drawings for civil, mechanical, electrical and control system components. Drawings were also created to show the classification and extent of the hazardous area zones. The drawing set was issued for client approval prior to being revised and issued for tender, construction and as-built. Orana Engineering managed the onsite commissioning of the system and provided a system handover to operations for implementation.