Luiz Felipe Leidens
Kepler Weber S/A
“Beyond structural safety, it is very important that the steel silos allow conditions for food safety on the operation, keeping the grains well maintained for a long period. For this, the use of automation and monitoring system is fundamental. Connecting the digital thermometry system, the drying automation and all equipment sensors of storage project to a platform able to interconnect all information in a single place, the food safety of post-harvest process increase significantly. Add to it the silo and equipment project structurally adequate to engineering international standards to guarantee a project with operational safety.”
The world population growth, according to World Bank data, will be 8,5 billion of people at 2030, the food demand will increase, especially in Africa and Asia, where the population increase projection is approximately 500 millions of people in each continent.
To FAO between 2010 and 2050, the food demand will increase approximately 70%. The scenario shows the necessity of expand investments in technology on the productive chain, once all growing food demand will generate increase of agricultural production. That is, from planting to harvest and post-harvest technologies needs to evolve to supply the global food demand.
The post-harvest step does fundamental role on this process, once the storage in good conditions preserves with safety the grain quality, allowing to regulate the production flow properly to do not overload the logistical system of grain producers countries.
The steel silos are structures used worldwide to do the grain storage in safety conditions. Well projected silos has aeration systems calculated according engineering parameters to the grain type, safe structural designing to operation and embedded technology to monitoring the storage product conditions.
Figure 1. Infographic of world population from 2015 to 2030Font: World Bank (2017)
The silos structural designing is fundamental factor of operational safety, and needs to follow engineering rules applying to the project. To evaluate the structural efficiency and operational safety of this kind of structure, Kepler Weber in a partnership with Dr. Carlito Calil Junior, Senior Professor of Enginnering School of São Carlos of São Paulo University, is doing the structural analysis of steel silos corrugated plates and stiffeners, considering the American Standard ANSI/ASAE EP 433:1991 (Reaffirmed 2011) to the storage product forces determination and the standards AISI S100-12 e AISC 360-10 to the parts resistance determination.
For evaluation purpose, two silo models were considered: SL 7222 e SL 9022, with storage capacities of 234.733 and 373.459 bushels respectively. The results interpretation is based on the used coefficient value to be bigger or smaller than 1,00.
When the coefficient used is smaller than 1,00 it means the mechanical efforts requested is smaller than the materials resistance, so the structural designing attends the physical efforts demand, according to the regulations.
Figure 2. Steel silos storage system Font: Kepler Weber (2020)
The graphics showed two curves: the blue line indicates the mechanical efforts requested and the red line indicates the full material resistance. When the blue line crosses the red line limits it means that the requested efforts are bigger than the material resistance, that is, the structural designing do not attend the safety rules.
Figure 3. Resistance versus stiffeners and plates demand – Silo Kepler Weber 7222 Font: Kepler Weber (2020)
Figure 4. Resistance versus stiffeners and plates demand – Silo Kepler Weber 9022 Font: Kepler Weber (2020)
To the Kepler Weber silos evaluated, we confirm that the used coefficient attends the regulation standards. The curve of requested efforts (blue line) always was below of material full resistance (red line), ensuring the structural safety of the steel silo.
Beyond structural safety, it is very important that the steel silos allow conditions for food safety on the operation, keeping the grains well maintained for a long period. For this, the use of automation and monitoring system is fundamental.
Figure 5. Critical Control Points of post-harvest process Font: Kepler Weber (2020)
For this purpose, in 2019 Kepler Weber launched a platform called SYNC, which contains digital thermometry, monitoring on the cloud and drying automation through IoT (Internet of Things) concept. On the technology development, it was mapped the critical control points of all storage process, as shown on the figure 5.
With the use of SYNC technology, it is possible to remotely monitor all these points, through sensors connected to the platform on the cloud, reducing losses on:
• Impurities and moisture determination errors;
• Inadequate movement and conveying;
• Equipment adjustments not efficient;
• Lack of cleanliness of equipment and installations;
• Poorly performed drying;
• Lack of storage ideals conditions.
On the storage case, specifically, the use of digital thermometry sensors connecting to the cloud make the grain conservation process ideal, through temperature reading with microchips that do not have read interferences and remote follow up on the app to smartphone in real time.
Figure 6. Digital sensor microchip and temperature reading with smartphone Font: Kepler Weber (2020)
A uniform grain temperature during all drying process is very important to have the best storage quality. This is possible with drying automation system that reads the moisture content of a sample, providing data to the control panel and the monitoring portal on the cloud, with the use of IoT technology.
Figure 7. Drying process data on the IoT platform Font: Kepler Weber (2020)
The drying data is measured by the drying temperature sensors, temperature and moisture of grain mass.
The moisture read is done by a sensor installed on the dryer flow, and regulate the dryer discharge, controlling the drying speed automatically, to determine the beginning and the end of each product cycle in the equipment.
With this system is possible to set the exit moisture content of your grain automatically, and to determine the right moment to discharge the product on the ideal moisture for storage.
Connecting the digital thermometry system, the drying automation and all equipment sensors of storage project to a platform able to interconnect all information in a single place, the food safety of post-harvest process increase significantly. Add to it the silo and equipment project structurally adequate to engineering international standards to guarantee a project with operational safety.
Figure 8. Grain exit moisture automatic control system on the dryer Font: Kepler Weber (2020)
As the harvest and planting process, the use of trustable technologies is the best way to post harvest chain, to maximize profitability, minimize loses, increase grain quality and to have a safe process to operators. Therefore, farmers, cooperatives and beneficiation units in general will have good conditions to contribute in global food demand supply with reliability, safety and sustainability.
ANSI/ASAE EP 433. Loads Exerted by Free-Flowing Grains on bins. In American Society of Agricultural and Biological Engineers. 2011
FAO – Food and Agriculture Organization of the United Nations. Food and agriculture projections to 2050. Available in: http://www.fao.org/global-perspectives-studies/food-agriculture-projections-to-2050/en/.
JANSSEN, H.A. Versuche uber getreidedruck in silozellen. VDI Zeitschrift 39:1045-1049. 1885
World Bank, Ending Poverty and Hunger by 2030: An Agenda for the Global Food System
Available in: https://openknowledge.worldbank.org/handle/10986/21771.