New technology for monitoring grain in flat stores

Flat grain stores are a convenient way to store grain commodities for a shorter period – as is often done in grain terminals. However, flat grain stores are also used for long term storage of grain, because it is a cheaper solution than steel or concrete silo storage.

Storing grain for longer times in flat stores poses several challenges:

• The stored grain is difficult to ventilate with proper air flow from aeration fans
• Even with proper fans and aeration channels, it is difficult to ventilate the grain evenly and achieve a uniform temperature and moisture concentration in the grain
• It is difficult to control the grain moisture during storage
• The stored grain is subject to more threats of infestation, rodent, and other risks than in steel or concrete silos

For these reasons grain monitoring is especially important in flat stores. If you are not timely alerted about emerging risks, losses will occur, both in terms of reduced grain quality and sometimes complete losses of grain.
The question is how to monitor the grain in flat stores, so losses can be avoided?

Historically applied monitoring solutions in flat grain stores
For the last 30–40 years especially two solutions have been used to monitor grain stored in flat stores. Both solutions have been based on temperature monitoring. Either temperature sensor cables hanging from the roof rafters have been applied, or spears placed in the grain to report the grain temperature.

Both solutions have posed several challenges in the application:

• Flat grain storage buildings often have a conveyer system to fill the storage. Then it is often not possible to hang anything from the roof
• If sensor spears are applied somebody must walk on the grain, which poses a sanitary risk, and the spears must be removed again before the storage is emptied
• Everybody with long experience knows that once front loaders are emptying the flat stores, it often results in broken sensors
• Finally, is the temperature sensing really the best solution in flat grain stores for efficient and present-day monitoring of the grain?

Avoid obstacles such as hanging cables and spears:
The mechanical problems with application of hanging sensor cables or any type of sensor spears are severe, and both cables and spears are often damaged by front loaders:

Why is temperature measurement in flat grain stores not an ideal monitoring technology?
Temperature sensors are used to detect temperature changes in the grain. If the grain temperature starts to rise and continues to do so, it is likely that a hot spot is under development with either insect or fungus infestation.

Avoid infestation of the grain!
Infestation with insects respectively fungus; the main threat to stored grain

Historically temperature measurement was the only way to detect infestation with insects or fungus, but this solution is outdated and should be substituted with CO2 (Carbon dioxide) and grain moisture monitoring. This technology is already recognised as state of the art in steel and concreate silos for monitoring the stored grain.

Temperature monitoring is not sufficient on its own for the following reasons:

• Temperature sensors have no range – they only measure the temperature where they are and grain is very insulating
• Grain temperatures in flat stores are more influenced by the environment than in tall grain silos, because the grain mass per square meter is less than in tall silos and therefore subject to more influence from the ambient temperature and humidity
• Temperature changes are more difficult to interpret as emerging infestation

How to detect infestation at the earliest possible stage?
The best monitoring solution is most definitely a system that alerts about infestation at the earliest possible stage. This can only be done with CO2 measurement as confirmed in multiple scientific studies. As mentioned previously, temperature sensors have no range, and they are therefore very limited in their ability to detect hot spots and will only detect them, when they are already including large grain masses. However, CO2 is a gas, and gasses spread evenly throughout the grain mass!

This means that even if a hot spot starts to develop near the surface or at the bottom of the grain, the CO2 will easily spread, and be detected by a sensor ten meters away! It is for this reason that CO2 monitoring is the ideal solution for monitoring emerging infestation in flat stores and in warehouses where commodities may be stored in jute bags.
A rise in CO2 concentration is always an indicator of increasing infestation!

Trend curves show condition of the grain:
Shows how temperatures in a grain mass evolves over time as infestation grows. The increasing CO2 concentration shown by the PURPLE curve is rising over time, this often happens weeks before the temperature sensors start to react, and when it is already too late to save the grain in good quality.

What is the ideal solution for monitoring grain in flat grain stores?
Based on experiences of the past an ideal solution for flat grain storage buildings must include the following to provide efficient grain monitoring and assist risk management:

• CO2 measurement inside the grain mass is needed to give early warning about infestation with insects or fungus
• Grain moisture measurement is a parameter that must be monitored to watch that the grain moisture concentration does not slide off target during long term storage
• The technical solution should be mechanical stable so front loaders will not damage the sensors system
• All monitoring data should be easily available in an App for swift surveillance and risk management actions

iGRAIN’s new All-In-One floor embedded sensor solution for monitoring flat grain stores
Over the past 25 years many solutions for flat grain stores have been supplied under the author’s watch. Most of them with temperature sensor cables hanging from the roof, and also many based on sensor spears; either hardwired or wireless. These solutions have in many cases not helped monitor the grain efficiently for the following reasons:

• Temperature measurement does not work well in flat grain stores
• Grain losses have been evident despite temperature monitoring
• In many cases infestation started in “corners” and escaped detection until it was too late
• There have been many mechanical damages to the cables and the spears applied by front loaders, and consequently a reluctance to apply monitoring sensors has spread

These experiences have led to the development of the new iGRAIN All-In-One Floor Sensor. The advantages of this solution are:

• The sensors are embedded in the floor, where the front loaders cannot harm them
• The sensors detect infestation fast and efficiently because they monitor CO2, grain moisture and temperature
• Relatively few sensors are needed, the distance between the new iGRAIN AIO floor embedded sensors can be up to 10 – 15 meters

New iGRAIN AIO Floor Sensors:
New iGRAIN AIO floor embedded sensor for monitoring grain in flat stores

Easy flat grain store monitoring with iGRAIN Smart App
Based on experience, it is just as important to have an easy and efficient communication to the grain operators and managers as an efficient monitoring system. Communicating lots of raw sensor data leaves the operators with questions on how to act. The monitoring data must be presented intuitively to interpret and act upon, easily accessible, easy to share across operators and managers, and they must be available for integration with other data from the site e.g. to a PLC or SCADA system.
App based communication is imperative to support daily operations and decision making on site. This is why the data from the iGRAIN AIO floor embedded sensor system enables operators and managers to access on-demand data through iGRAIN’s intuitive Dashboard Manager and Smart App. Both raw sensor data and AI based data computations are shown on demand to guide real-time decision-making with the clear target to avoid grain losses.

iGRAIN Smart App
iGRAIN Smart App including AI based data processing to guide real-time decision-making

The iGRAIN Smart App is unique on the market as it communicates the following data:
1. The estimated percentage of the area covered with grain in the flat grain store, and the corresponding tonnage of grain
2. The true grain quality, and the corresponding risk factor which quantifies the infestation
3. The estimated safe storage time in weeks for the monitored grain mass

The new iGRAIN AIO Floor Sensor is supported by the iGRAIN Smart App, which enables remote access to true grain quality for easy grain management. The unique, state of the art iGRAIN AIO Floor Sensor system for monitoring grain in flat stores is the first of its kind.

 

The above article was brought in Milling&Grain’s August issue 2024 – link to Article in pdf format: Read article

Link to product page: AIO Floor Sensor for flat storage facilities (crop-protector.com)