Each tank cleaning project is unique. A number of variables come into play: the design and condition of the tank, amount and composition of its contents, constraints of the work area and much more. Moreover, circumstances can change quickly once a project begins and new challenges are discovered inside the tank.
The bottom line? There are no "cookie-cutter" solutions. To execute a job safely and efficiently, a tank cleaner needs a full arsenal of technologies, the expertise to use them optimally, and the ingenuity to problem-solve in real time once a project begins. It's a skillset USA DeBusk has put to work often.
USA DeBusk was recently called to clean and degas a tank at a Gulf Coast chemical plant. The 148-foot insulated tank was in fuel oil service and contained roughly six inches of sludge and mounded fine solids. The fixed cone roof had partially collapsed, with the center of the structure suspended roughly 15 feet above the tank floor. The integrity of the roof beams was unknown. VOC and benzene readings were high. Pockets of undisturbed and potentially hazardous material in the tank had accumulated over eight years of service, adding to the unpredictable nature of the project.
For maximum safety, the tank had to be cleaned without manned entry. LEL and VOC levels needed to be reduced sufficiently to allow an inspection drone to fly inside and assess the damage for repair planning. Adding to the challenges, the available workspace outside the tank was tight and congested.
USA DeBusk responded with a project plan that included nonentry technology. A track-drive remotely operated vehicle (ROV) robotic tank cleaning system with a diluent spray bar and suction hose was used to liquify and remove material. An on-board auger attachment was added to break up compacted solids. A camera and lighting system mounted on the tank shell provided a visual feed, enabling the ROV pilot to operate the unit from a mobile control room. A remotely operated manway cannon sprayed additional water and cutter stock.
USA DeBusk planners engineered an operational setup with a small footprint. The ROV was capable of entering the tank through a 20-inch manway.
The crew began by spraying diesel cutter stock to dilute hydrocarbons into a pumpable state for removal via the ROV suction and tank water draws. This was followed by a series of water and surfactant washes, using degassing agents to reduce VOCs and chemical additives to encapsulate hydrocarbons and prevent them from reattaching to walls, floors or ceilings.
The crew removed approximately 90 percent of the material to reduce LEL and VOC levels to permitted specifications. The project was completed with no safety incidents, and the customer complimented the team for good housekeeping, excellent communication and efficient responses to unexpected issues.
USA DeBusk teams have amassed an impressive record of not only cleaning tanks, but also processing materials to reduce outhaul and recover valuable product. Along the way, they have overcome the obstacles that make each project unique, whether implementing degassing and vapor control, dredging an API basin or adapting to other customer requirements.
For more information, visit www.USADeBusk.com, call (844) 243-5557 or email sales@USADeBusk.com.
