March 2020

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Optimization: Plan before main air blower disaster strikes

Weeks before a planned overhaul of its coker unit, a synthetic crude plant’s main air blower for the furnace failed, throwing the engineers’ plans into disarray.

Weeks before a planned overhaul of its coker unit, a synthetic crude plant’s main air blower for the furnace failed, throwing the engineers’ plans into disarray. Not only did the coker shut down prematurely, but the main air blower now needed repairs, resulting in potential safety risks and significant losses for the company.

To remedy the situation, the authors’ company successfully delivered 150,000 sft3/min. of oil-free air, including 33 MW of power; 2,000 t of cooling tower capacity; 56 pieces of electrical distribution equipment; and a low-voltage 480-V cable. The engineered solution was managed constantly by plant personnel and outside technicians and operated uninterrupted for 18 d until the main air blower came back online. Those extra 18 d of steady operational time earned the refinery $70 MM.

While the turnaround schedule got back on track and the plant fixed the faulty blower with minimal impact on productivity, the plant learned the importance of a contingency plan for a main air blower outage—a critical piece of equipment with a lifespan of approximately 20 yr.

A contingency plan reduces the risks associated with an unexpected outage, planned repairs or replacement of the main air blower, as well as provides a clear strategy to quickly execute steps to keep production steady and workers safe.

What to ask and how to plan

First, plant engineers must ask and discuss the right questions, including: What is the condition of the main air blower? What is the impact on operations should the main air blower fail? How will the plant manage in an emergency? What backup equipment, utilities and installation components are required?

Personnel should discuss how to manage a scheduled and unscheduled main air blower outage. Think of the contingency plan as the plant’s insurance policy on the main air blower because it is not a matter of if the equipment goes down; it is a matter of when the equipment will fail.

A contingency plan not only reduces downtime by speeding up the deployment and installation of a backup system; it also identifies and budgets the best possible equipment at negotiated costs well in advance.

For example, a major refinery in the San Francisco Bay Area developed a contingency plan for its main air blower after plant personnel noted unusual vibrations. With a temporary compressed air, power, cooling and heating company, a sophisticated contingency plan, with diagrams and selected equipment, is now in place for power and cooling water.

Cover all bases

When creating a contingency plan, engineers must go through each section methodically, identifying every item or power source that could go down. Consider every eventuality, including vulnerabilities with existing backup measures. It is imperative to trace every process from start to finish.

Logistics are critical, as well. How will the plant physically transport the equipment needed in and out of the site? How will the plant power it? What are the most crucial needs for temporary utilities? What is the order of priority? Which issues can be handled in-house, and which can be handed over to a rental utilities’ vendor? Every question answered will raise another five questions, but it is better to address every eventuality in the present than on the day of an emergency.

Run a site survey and a dry run

While in the discovery phase of contingency planning, schedule a site survey with a temporary utilities provider. The rental provider will walk through the specific rental equipment it can provide—together with any supporting ancillaries—and explain its logistics strategy, including transport, load-in and equipment placement. Experts will examine the existing setup, including power voltages, cooling pressures, flowrates and connection requirements such as cabling, pipework modifications and building adjustments.

Not only will the vendor be able to identify any issues that have been missed, but they may also be able to suggest alternatives to complex problems. Best of all, the vendor might be able to ring-fence a fleet of critical utilities and generators for use, with costs agreed upon upfront. Then, the perfect contingency setup is only an activation phone call away. Finally, see what happens when the backup system turns on. Examine all installations and temporary equipment. Is everything working as it should? Involve the whole contingency team in the test. If there are concerns or requests, raise them before it is too late.

Safety First!

Remember that safety considerations do not matter any less in an emergency. The contingency plan should recognize and anticipate dangers and demonstrate how to keep the team safe while enacting the backup strategy. The planning process needs to take note of site-specific safety requirements. That goes for any equipment brought in from outside, as well.

In conclusion, there is no time like the present to plan for a scheduled or unplanned outage of the plant’s main air blower. A contingency plan provides a clear strategy and keeps workers safe and production steady.

It is a team effort, so work with the right utility vendor to ensure that the right people are on the team. While planning may initially cost tens of thousands of dollars, that is minimal compared to the risk to worker safety and potentially millions in lost production. HP

The Authors

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