From wastewater, chemical and petrochemical industries to mining and agriculture, storage tanks are an integral part of process manufacturing. They come in different shapes and sizes, and their contents vastly vary from chemical fluids and liquids to bulk solids like cement, aggregates and cereals. Nevertheless, irrespective of their applications, effective tank level monitoring and control are imperative to any industrial operation.

At the very least, overfills result in material and production loss, while threatening to damage the silo itself. For tanks containing hazardous materials, spilling could also lead to disastrous environmental impacts and associated cleanup costs and fines. Failing to refill feedstock tanks in time could also cause businesses to run out-of-stock, which leads to delayed production and delivery.

The Search for A Versatile Tank Monitoring Solution

Despite its importance, industrial tank monitoring has been daunting and inefficient. Quite often, workers must manually collect level readings on site, which is time and labor-intensive and often unreliable. With manual checks done a few times per day or even per week, refilling or emptying is planned based on mostly speculation and guesswork. Adding to the challenge, many industrial silos are situated at remote sites, making field trips logistically difficult. Also, malfunctioning equipment and other unforeseeable factors may cause an abnormal change in the content levels which could lead to overstocking a site or dispatching trucks to offload only half-full silos. Worse, there could be stock depletion or material overflows, both of which are detrimental to running operations.

Industrial monitoring solutions using wired sensors have been introduced to provide more accurate insights into tank levels and eliminate the need for dispatching staff to the site. Nevertheless, trenching hundreds or thousands of meters of cables around complex industrial facilities is expensive and cumbersome. It often requires invasive changes to the physical infrastructure or shutdowns of running equipment. What’s more, once the network is in place, adding new sensors or moving around currently connected tanks could cause many complications. Not to mention, in many scenarios, the remote and challenging location of silos could mean that cabling isn’t an option altogether.

Leverage the Power of IoT for Tank Monitoring

Compared to wired communications, a wireless IoT solution for industrial tank monitoring prevails in many ways. Wireless connectivity is flexible, cost-effective and much less of a hassle to deploy. With a long-range and power-efficient solution like Low Power Wide Area Networks (LPWANs), you can easily connect hard-to-reach assets using sensors operating on independent batteries that can last for years.

Thanks to simple maintenance and low device and network costs, LPWANs can be implemented at a fraction of the cost of their wireless alternatives. A robust, scalable LPWAN technology also provides the seamless integration of new connections into the network with minimal complexity while not compromising Quality-of-Service. As such, you can connect a large number of storage tanks simultaneously and aggregate a wide array of sensor measurements at each tank. By unlocking 24/7 asset visibility and feeding this data into enterprise management systems, a wireless IoT architecture enables enhanced production planning, asset management and protection and operational safety.

1. Improved Production Planning with Level Monitoring

Ultrasonic or non-invasive capacitive sensors attached to wireless transmitters can measure and communicate stock level data to the control center located kilometers away from the site. Once the level exceeds or falls below the specified threshold, an alarm is automatically triggered for timely dispatch of trucks to empty or refill the respective silos. For feedstock tanks, real-time level data assists in effective inventory planning to avoid out-of-stock conditions that lead to expensive production halts.

By aligning schedule and routes of field trips with actual production needs, operators can maintain optimum tank levels, eliminate emergency deliveries and maximize delivery/pick-up quantities. This translates into improved workers’ productivity and saved fuel costs while preventing overfills and production downtime. On top of that, continuous level measurements can help detect abnormal changes in the stock quantity potentially caused by malfunctioning valves or pumping components.

2. Leak Detection and Structural Integrity Control

Beyond level monitoring, IIoT architecture enables leak detection of storage tanks to avoid catastrophic incidents. Vacuum and pressure sensors can identify and alert a drop in pressure that indicates hazardous leaks and material release. Likewise, low-frequency acoustic sensors can detect small structural events like delamination, crack initiation and growth through generated sound waves. Synthesizing various sensor data enables the development of an early warning system and automated emergency workflows to mitigate dire consequences of tank failures.

Taking one step further, smart sensors can be installed to check on the structural health of tanks round-the-clock for anticipation and prevention of potential leakages in the long run. Wireless corrosion detectors are instrumental in detecting wear-and-tear like reduced wall thickness over time due to abrasion. Simultaneously, vibration sensors can diagnose unwanted events such as jolted tanks caused by nearby pick-up vehicles, while temperature readings help monitor unusual reactions inside chemical tanks that may cause structural instability. Leveraging advanced analytic tools, conditions that lead to failures can be identified over time. This allows operators to prioritize maintenance tasks based on the urgent needs of specific assets.

3. Thefts and Tampering Protection

Tanks used to store valuable commodities like fuel stocks are highly vulnerable to vandalism and theft. Despite the explosive danger of fuel compounds, thieves are still prompted to use perilous tools like drills and blow torches to extract materials out of the containers. Beyond product loss, the result of such an attempt may be a disastrous fire with irreversible damages. By deploying vibration and motion sensors, operators are instantly informed of any dubious activities on storage tanks, especially at night. To increase the reliability of the automated alert system, these sensors could also work in concert with level readings that signal unusual loss in content mass.

Implementing IoT for tank monitoring delivers tremendous benefits to process industries. Innovative wireless connectivity like LPWAN enables automatic data collection from even the most remote storage tanks without substantial capital and labor investment. Having complete insights into their assets, companies can make informed decisions to reduce costs and enhance operational efficiency and safety.

Part of this article was originally posted on Flow Control Magazine