MPS: Hasakona

Challenges

• Packing accuracy: Make sure the pusher and packing system consistently cut off the sludge flow to reach a precise weight of 1 ton, given the difficult viscosity of the sludge.

• Continuous reliability (high availability): Prevent downtime in the residual sludge handling system. A failure could cause sludge to pile up and disturb the main refinery process.

• Material flow coordination: Control and balance the sludge flow automatically from the conveyor to the main and secondary hopper without overflow.

Solutions

• Redundant control system: Implemented a PLC Modicon M580 Redundant System control architecture from Schneider Electric. It leaves no single point of failure in controlling the conveyor, hopper and packing actuators, so operation continues without interruption.

• Central monitoring: Used EcoStruxure SCADA Expert (Schneider Electric) to give operators full visibility. The status of both hoppers, the conveyor speed and the 1 ton load reading (scale) are monitored in real time to keep the process within its parameters.

Lessons learned

• A redundant control architecture at PLC level is critical for supporting utilities (such as waste and sludge handling) in an oil and gas refinery, to maintain zero downtime.

• A responsive link between the weight sensor in the packing system, the PLC and the SCADA is the key to handling the variation in the sludge and reaching the 1 ton packing target consistently.