The Elephant In The Room

The world is currently undergoing a radical digital transformation, with the digital world and industrial production coming together. This cohesion is what the Internet of Things (IoT) and Industry 4.0 aims to bring about. Benefits such as increased energy efficiency, flexibility, accuracy, simplified logistics processes and value chain optimisation explain why Industry 4.0 is a key topic of conversation within the fertilizer production industry. With this in mind, Bagtech continues to develop its products with the latest in digital technology.

Greater energy efficiency

The company has focused its efforts on continuous blending solutions due to their naturally low energy consumption, but not without encountering challenges. Batch blenders have a more straightforward control philosophy, are typically more accurate, and are less prone to disruption but come with a significant caveat: high energy consumption. Batch blenders require larger motors and higher throughput components to achieve the same production as a continuous blender. By introducing digital technologies to continuous blenders, accuracies better than those of batch blenders can be achieved, with the added benefit of greater energy efficiency. A primary energy consumption study was carried out on two recently commissioned plants, which showed that the continuous blender consumed 45% less energy compared to its equivalent batch blender at 70 tph. Energy consumption for each major component can be logged and monitored automatically. Certain events may trigger an alarm; for instance, an increase in the average energy consumption of a bucket elevator may indicate that it requires maintenance and a catastrophic failure can be averted. Information such as energy consumed per batch is also available for accurately tracking costs.

Compressed air is a common source of energy for fertilizer production plants, but if a plant that uses compressed air is not well-maintained it can lead to significant energy wastage. Fertilizer has very corrosive and abrasive properties and can therefore cause premature wear and tear on pneumatic components. The company is looking into implementing an early warning system that monitors the flow of compressed air and triggers alarms when it detects air leaks in the system.

Accuracy

Accuracy is a critical factor for any fertilizer production facility. Inaccurate blends can have extremely detrimental effects on the soil they are applied to. Loadcells play a pivotal role in fertilizer production as they are the most commonly used instrument for measuring the dosed amounts. A loadcell transmits a tiny voltage signal based on the load applied to it. This small voltage is measured by a loadcell signal amplifier and converted to a digital signal for the plant controller to read. Traditional methods have the loadcell signal amplifiers mounted in a central location close to the plant controller. This type of topology can lead to excessively long loadcell cable lengths, where electromagnetic interference has a detrimental effect. The loadcell signals are so small that the slightest form interference can have a negative effect on the accuracy of the blend.

The implementation of EtherCAT in the company’s plants has solved this issue and provided several additional benefits. EtherCAT is a high-speed real time industrial network designed to connect devices using a single cable run throughout the plant. It allows the 24-bit loadcell signal amplifiers to be mounted as close as possible to the loadcells, thus minimising the length of loadcell cables to a few metres and increasing the stability of the loadcell data. The real time capability of the network ensures the plant controller receives data from the loadcell signal amplifiers at an exceptionally high rate. The quicker the plant controller can receive information, the quicker it can make informed decisions, thus leading to greater accuracy. This decentralised topology also makes plants modular and significantly reduces wiring. The latest plants commissioned with EtherCAT have shown an increase in fertilizer blend accuracy of up to 22%.

Another key contributor to accuracy is the intelligence in the plant controller. Digitalisation allows access to data like never before, but if the data is not processed or analysed, it is a white elephant. The software in the company’s plant controller uses machine learning algorithms to make predictions and adjustments, thus increasing accuracy over time. Each raw material or constituent used in the blends has a profile stored on the system containing unique data about it. This data builds up over time so it can be used in the future to make better decisions.

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