Today’s bulk-storage solutions are relying more and more on fully automated systems. Here are some common automated systems now engineered into domes:

• Systems monitoring conveyors are especially important as poor belt-idler maintenance is one of the greatest causes of fire within storage facilities. If idlers fail to spin properly and the belt continues moving anyway, the system can take fire and the conveyor can carry the flames right into the dome. Sensors are also installed to analyze bearing alignment. In both instances, the systems shut down when a problem is detected, and site operators are notified.

• Plug-chute sensors detect when a chute gets plugged, preventing large spills. Damage belt detectors detect damage that may turn into the conveyor failing while the belt is loaded with product.

• Temperature and humidity control loops are essential; a cable array hung from the roof monitors both. Using this information, a controller or processor starts and stops fans or dehumidifying units to keep the levels within specified amounts.

• Multiple-gas detection systems monitor off gasses. In the case of wood pellets, for example, this system tells customers how aged pellets are by identifying where they are in the process of decomposing, and watching those levels provides clues that fire could soon be possible. For instance, a Firefly gas-detection system detects off-gases as well as those produced by smoldering.

• Point-level monitors identify the height of the product in the dome, and more specialized 3D monitors chart the surface of the pile and its shape—information crucial for inventory management and knowing how much product is being stored (and is aging, if applicable).

• Moisture meters can be installed on the inbound feed to detect if the product is off spec, failing to meet requirements for heat or moisture. Customers are alerted if bringing in something too hot, too dry, or too wet and can reject the product.

• Conveyor components can be mechanized, allowing a facility manager to easily control product-direction flow. For instance, if product ought to be stored in a specific dome, all diverter valves move so product goes where intended with the push of a button. Similarly, systems can control whether product moves from dome to dome or out to ship, train, or truck. Operators do not have to check if the diverter gate is in the correct position because the PLC receives feedback from the gate showing its position.

• Convenient safety devices make it easier to halt operation as needed. Most mechanical systems are engineered with emergency stop buttons in key places throughout the facility. Along the conveyors, a pull-cord system allows workers monitoring the material handling to stop operations even when a stop button is out of reach.

The two most important features of operational safety—housekeeping and maintenance—can’t be engineered into the system and must become part of routine operations. But when automated systems and routine maintenance work in tandem, a site runs more efficiently and safely day in and day out.

For years the bulk-storage industry was dominated by options requiring manpower and near-constant attention, but today’s trend leans more and more towards fully automated systems. To get the best systems, a turnkey solution has become more common, where companies select one provider for all the storage and handling systems necessary—plus operation made possible by pushing a few buttons.

“Lately there’s really been a shift to a complete automated system,” said Casey Bame, engineer and automation designer for Dome Technology projects. “In the long run (companies) can save a whole lot of manpower from not having someone out there turning things on and off.”

One of the greatest benefits of automation is that potential problems can be detected early enough that the site manager can be alerted before the system has to shut down. That way, material handling can continue without interruption as issues are resolved.

In pursuit of a well-automated facility, companies ought to consider selecting one provider for construction, where the mechanical, structural, electrical, and automation engineering are all done by a single company; this ensures better coordination since coworkers manage their portions of the project together, crafting systems that run smoothly with one another, Bame said.

Dome Technology engineers can design a variety of control systems with the most common being systems that run on a programmable logic controller, a complex computer-and-sensor system collecting data, analyzing it, and dictating that operations function properly and run in the correct sequence—Conveyor A before Conveyor B, for instance. Utilizing sensors on the conveying system, the PLC can inform the operator if the belt is getting out of alignment, not running properly, or if the bearings are getting too hot; advance notice can prevent costly repairs and unnecessary downtime.

With the importance placed on safety, the PLC along with pull cords and push buttons can be valuable tools to keep people safe and machinery undamaged. The use of variable frequency drives to dictate the speed of the conveyors can help a plant run more efficient and prevent expenses such as the high in-rush current of large motors.

The design and engineering of the automation is completed during the same time as the mechanical system, and they work together to provide a proper system that meets the customer’s needs. Upon installation, an on-site operator—someone from the customer’s company—is trained on how the systems work.

This kind of engineering eliminates much of the potential for human error and relieves the burden on site operators.

Check back next week for a list of automated systems now engineered into domes.

Although portside property comes at a premium, many companies are willing to pay the price for one obvious reason: easy access to shipping.

But buying land on the water comes with its own limitations, like less land for the money, water-saturated soils and environmental considerations too. With this in mind, pre-planning becomes essential for making the most of a port project. Here are a few suggestions for planning such a project:

Making design decisions

Oftentimes those who buy land on a port get less property for their money, requiring smart decisions to achieve the needed storage on a smaller parcel of land.

It’s important to research site requirements before plans begin, and often the best way to make the most of portside property is to build vertical, rather than horizontal, storage.

Choosing the best foundation for wet soils

Innovative foundation options allow customers to remediate less-than-desirable soils, sometimes at a lower expense and with a shallower foundation than expected.

An experienced engineering team will provide options that best complement a specific site, whether a shallow foundation or a deep foundation is required.

Optimizing material-handling systems

Selecting the ideal conveyor system requires an understanding of the stored product and innovative conveyor systems that uses less property. A belt-conveyor system, for instance, requires significant linear footage; as the belt climbs, the material wants to slide backward, so the angle of incline has to be adjusted accordingly. Looking at options beyond the traditional can shorten conveyor distances, often accomplished by increasing traction within the conveyance system.

Loading and unloading

The typical model for unloading product is a 20- to 30-foot-deep pit with a hopper that moves product onto a feeder conveyor coming out of the ground. But for facilities near water and with soggy soils, the pit’s excavating, dewatering and waterproofing costs alone are prohibitive.

Systems are available for unloading at grade or into a shallow pit. For instance, a rail car might pull directly over one of the Ashross RUM models, which provide either shallow in-ground or above-grade conveyance via a walking floor. Facility managers have to allow time for the system to unload the product, rather than just dropping it and advancing the cars, but customers can save on pit size.

Protecting the environment

Port code enforcement is rigorous, and one advantage with domes is that the structure is airtight, reducing or eliminating the chance of byproduct escaping the structure. Silos crafted by a continuous concrete pour from bottom to top are also seamless and discourage byproduct escape.

To read the full article, visit the April issue of Ports & Terminals, a World Cement publication.