Total transparency

The skies are clear but for the occasional puff of cloud, and the outdoor water slide at the Vestbadet aquatic center in the Danish town of Viborg sparkles blue in the sunshine. On this perfect summer’s day, three children are racing each other down the slide’s triple lanes, reveling in the 25°C warmth of the pristine water. If it were up to him, Kenneth Laursen would be cooling off in the pool, too. A dip would be just the thing – provided, of course, that the water is the right temperature, has a pH of between 7.0 and 7.6 and contains at least 1 mg of free available chlorine per liter.

Kenneth Laursen knows all about swimming pool water. His company, Cabola ApS, supplies close to 300 sites all over Denmark with the chemicals they need to provide clean swimming conditions for several hundred bathers at a time: primarily sodium hypochlorite solution and sulfuric acid, along with hydrochloric acid and cleaning agents. In water, sodium hypochlorite dissociates into hydroxide ions and free available chlorine. The latter not only inhibits algal growth but also oxidizes the dead skin cells, sweat and sunscreen washed from swimmers’ bodies – a chemical reaction that produces chloramines, the compounds that give swimming pools their characteristic ‘chlorine’ odor.

How frequently these chemicals need replenishing depends on multiple variables: temperature, the level of solar radiation and the number of people in the pool. Kenneth Laursen: “It also makes a big difference to chlorine consumption whether swimmers shower before entering the water.” That means the daily amount of sodium hypochlorite added may vary between 10 and 20 ml per cubic meter of pool water. As a result, Cabola’s customer resupply intervals are rather variable, which can lead to logistical inefficiencies. “Whenever the Vestbadet pool used to order from us, we’d phone around our other customers in the Viborg area to see if they needed anything,” Laursen explains. “But even then, our delivery truck
would often leave the depot half full. That’s something I wanted to change.”

Kenneth Laursen initially sought a solution by fitting his customers’ storage tanks with remotely monitored gauges. But this proved too expensive, and the immersion probes they used couldn’t withstand the corrosive chemicals. In the end, he found the solution to his problems at Endress+Hauser. Now there is a dashboard that gives Cabola employees 24/7 visibility into their 300 customers’ chemical inventories and consumption rates, providing the key to tailored replenishment.

“The Cabola example shows how transparency can optimize logistics and inventory processes,” explains Christian Reichert, director of engineered solutions at Endress+Hauser. Transparency-enhancing solutions have indeed been widely used for many decades. “Financial performance and competitiveness in the process manufacturing industry are highly related to effective inventory management around materials storage, transfer and distribution,” Reichert says. High inventory levels improve suppliers’ ability to meet demand but tie up a lot of capital. Lean inventory levels, on the other hand, cut costs at the expense of the ability to deliver on demand. “That’s why companies use inventory management solutions: to find the right balance. It’s about making their processes more efficient and boosting productivity.”

For a long time, though, such solutions were not an option for operators like Cabola where the storage units are intermediate bulk carriers (IBCs) – stackable plastic containers with capacities ranging from 300 to 3,000 liters. Used in many industries for transporting and storing liquids, IBCs tend to be relocated frequently, often in quite far-flung places. “Conventional wired measuring systems are generally too complex and pricey for small installations or applications that don’t have overly stringent safety requirements,” explains Christian Reichert. “So, there was no cost-effective way to automate their measuring processes.” Gauging fill levels in smaller IBCs that move around basically meant making do with visual checks, periodic sampling or estimates.

But now, electronics miniaturization and cloud technology have come to the rescue. In 2019, Endress+Hauser launched its Micropilot FWR30 – a compact level sensor that sits on the tank’s exterior and sends radar waves through the plastic wall into its interior. The technology determines the level contactlessly using time-of-flight measurement. Power for the sensor comes from a lithium-ion battery that can last up to 15 years depending on measurement interval. The instrument has an inbuilt SIM card enabling access to the cellular network, which is used to transmit measurement data to the Endress+Hauser Netilion cloud – no gateway involved. From there, digital services visualize the data, so authorized users can monitor fill levels from any tank gauge out in the field.

This same solution also works in remote locations like the vast countryside that Australians call the outback, as Endress+Hauser international business development manager Volker Schulz explains. The customers he supports on this sparsely populated continent include a company that produces and supplies concrete additives to construction sites. The logistics of this can be quite challenging. “If the concrete plasticizer runs out, the building site grinds to a halt until fresh supplies arrive from a thousand kilometers away.” On the other hand, early reordering just to be sure can be equally problematic, because every truck trip into the outback for anything less than a full tanker load of chemicals is bad for profitability and sustainability.

The company now has several hundred FWR30 sensors in use across various countries and uses the Endress+Hauser SupplyCare cloud-based inventory management platform to give its customers 24/7 access to dashboard maps revealing information about each of their tanks. This digital service does more than monitor tank levels; it also tells the customer whether the stored product has been withdrawn from a tank and processed at the right temperature – an important parameter in places where temperatures can rise to 50°C. Additionally, the system generates short-term forecasts based on monitored changes in tank levels. “Any fall below a set level will trigger an alert or automatically initiate a replenishment order,” Schulz explains. This eliminates the risk of empty tanks and stop-start construction work.

The pandemic has driven further refinements to this technology. Christian Reichert: “The delivery problems encountered during the pandemic and growing expectations around sustainability have made companies even more aware of transparency as a factor. Customers now also want the ability to monitor their supply chains, from small segments to the entire thing. We’re seeing strong demand here, particularly in the construction materials sector.” Endress+Hauser responded by working closely with users to extend Micropilot FWR30’s functionality. The instrument now has a process connection for metal tanks and silos – to allow for the fact that radar beams can’t penetrate metal walls. In addition, it can now measure bulk solids and has locationtracking capability.

One of the customers involved in developing all these innovations was Profibaustoffe Austria GmbH, a company that processes limestone from its own quarry into cement, mortar and render for walls, floors, facades, gardens and road construction. Supplies of these materials leave the company base in Ernstbrunn, Austria, destined for construction sites around the country and across the border in Eastern Europe from its base in Ernstbrunn, Lower Austria. The transport containers are cylindrical steel silos that can be swapped out or refilled as required. Even empty, the silos are quite valuable, so it’s worth knowing their location at any given time. And that’s where Micropilot FWR30’s GPS function comes in. The technology also helps with route planning.

Thanks to Micropilot FWR30, the producer and supplier of concrete additives in Australia has even developed a new business model. The company now manages its customers’ inventory, guaranteeing that they will always have enough plasticizer in their storage tanks. And in Denmark? Kenneth Laursen has achieved his goal of optimizing truck capacity utilization, cutting fuel consumption by almost 10 percent. And he, too, is leveraging this new technology to strengthen relationships with his customers: “If outdoor swimming pool operators contact me to order replenishment chemicals in late summer, I’ll gladly advise them against that if their current usage patterns indicate that existing stocks will last through to the end of the season,” he explains. “My customers really value that. For me, having good, long-term relationships with them matters more than short-term sales.”