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Investing in Updated Instrumentation Can Save Millions

Wireless Tank  SolutionEvery industry professional understands in theory that outdated instrumentation costs money – but making a change can seem more costly and vastly time consuming .  One producer of liquid asphalt, however, proved how important updated instrumentation technology is in harsh reality for all to see.

The producer had 42 tanks for liquid asphalt and its level devices were manual tape-type instruments that were very unreliable, as they were prone to sticking, breaking, and freezing, and the guide cables would get gunky build-up. In fact, these route-based measurements could not provide data to indicate product loss or track wrong product transfers, and there was no compensation for dramatic level swings in very large tanks due to temperature changes.

The issues caused by the outdated system were twofold – a huge impact on inventory management and an even more significant issue of safety. The company needed to reconcile inventory to the nearest 1000th, but inaccurate level created a monthly error rate of up to +/-5 percent, which could equal up to $1,125,000. These kinds of inventory swings were a critical financial risk since it’s difficult to defend the errors in an audit for revenue reporting and tax purposes.

The safety issues were realized a few years earlier when a tank exploded and it was determined the cause was a frozen tape gauge. The plant engineers and operations also realized that if a leak had happened over a weekend, it could have gone undetected for days, leading to a major safety and environmental risk.

The plant realized it needed to bring automation to a 1940s terminal with a solution that provided continuous, accurate level measurement; was easy to convert to tonnage for inventory management; included a ground-level display for visual redundancy, which was a new insurance requirement after the accident; and was easily accessible and maintainable. However, the size of the plant footprint and limited existing wiring to tanks made wired pressure instruments cost-prohibitive.

Wireless Tank SolutionThe solution was to install a wireless gateway in the center of the site grounds and build a wireless mesh network that connected each of the RosemountTM Wireless 2051L pressure transmitters  that were outfitted on each tank. Emerson Wireless THUM™ Adapters were added to existing radars on mix tanks and two Rosemount 648 wireless temperature transmitters were added on pipe clamp sensors to boost signal strength in some areas. With the new system, all product is stored, tracked, and inventoried, and volume is calculated using API density and temperature correction formulas.

Since the implementation, there haven’t been any safety incidents related to poor level control and the company has had no irreversible off-spec product blends. In addition, the company has saved between 40 and 80 hours per month by the accounting team reconciling inventory, and dropped from having potential average error rates of $500,000 or more to around $2,000, and as a result, they have less uncertainty with tax audits.

Earlier this year, the new system more than proved its worth. A 6-inch valve containing 1.5 million gallons of liquid asphalt cement at 300o F broke in half on a Friday evening. The asphalt cement began draining from the tank at a rate of 800 gpm. The wireless system notified the terminal manager via text and e-mail, so it was caught and addressed very quickly. If they had the manual system, that leak would likely not have been discovered until the following week and would have lost approximately $3.5M worth of liquid value, plus clean-up costs and construction costs would have exceeded $5M.

The implementation of 21st century instrumentation has given the plant the ability to more effectively control inventory and batch processes as well as improved safety.

Have you seen examples where updated instrument technology has saved you money?

2 Replies

  • A good example of how technology helps people digitally transform their work processes to improve quality/yield, productivity, throughput, and flexibility/agility. Other applications include:
    -Operator rounds
    -Local Control Panel (LCP)
    -Offsite tank farm storage tank
    -Wellhead Control Panel (WCP)
    -Offsite standby pump
    -Consumables inventory
    -Temperature profile
    -Valve and damper position
    -Rotating kiln and reactor
    -Process troubleshooting

    Learn how other plants deploy fieldbus and wireless sensors from this essay:
  • I know that these tanks were previously not automated, so it is a big step to change that. Zac did a great job working within his customers particular needs. Looking at your own application, when you are dealing with asphalt, the application can be tricky to solve with traditional level devices. Fortunately, Emerson has a long history of very reliable and accurate measurement utilizing our free space radar gauges with the unique parabolic antenna. The original heavy-duty parabolic antenna design has been used in asphalt applications since 1984. For more than 30 years, this type of antenna design has proven to be the most reliable radar gauge antenna for asphalt tank gauging.

    The unique drip-off design, makes the antenna less susceptible to contamination from water condensation and product build-up. This ensures higher accuracy and improved reliability making it an outstanding choice for use in tanks prone to heavy contamination.

    The 5900 system and TankRadar Pro radar gauges are easy to install during operation. The gauges can be mounted in most existing manholes.

    There are no moving parts or contact with the product, making this installation extremely low maintenance.

    A blown asphalt tank is the most difficult application due to the harsh environment in the tank. When blowing in air, the product splashes, foams and vaporizes. Furthermore, because the product is sticky, all surfaces in the tank become heavily contaminated.

    High accuracy is often required in the large bitumen storage tanks (approx. 20 m (66 ft.) high) that are typically used at refineries or terminals. In such tanks, the most reliable measurements can be attained with the parabolic antenna on either radar level gauge 5900 system or TankRadar Pro. Because of its custody transfer accuracy, 5900 is often the best choice.

    The parabolic or large cone antenna make TankRadar Pro an excellent choice for smaller bitumen tanks, around 5 - 10 m (16 - 33 ft) high and where temperatures range from about 80 to150 °C (176 to 302 °F). Pro has a high signal-to-noise ratio and accurately manages internal structures such as heating coils. The cone antenna is most suitable for lower temperatures. For high temperatures, over 150 °C (302 °F), the parabolic antenna is recommended.

    The 5900 system is compatible with all major tank gauging systems. By emulating the existing tank gauge, the 5900 system can utilize the field bus and power supply that are already installed.

    Lance Berry  | General Manager | Rosemount Tank Gauging North America, Inc.