Two solutions for IMF: monitoring the weight during the coffee roasting process and controlling ground coffee entering and leaving the storage silos. Integration with management software to monitor and improve product traceability.
In the coffee industry, weighing is a fundamental component.
Weighing systems are used throughout every stage of the production chain: from cultivation and harvesting of the coffee bean (green coffee), through roasting, to grinding and packaging.
IMF is an Italian company specialised in the design and manufacture of artisanal and industrial coffee roasters, as well as complete systems for the coffee industry.
In collaboration with IMF, we developed two weighing systems for two different stages of coffee processing: roasting and ground coffee storage.
Contents
- Weight monitoring on the loading hopper and destoner of an artisanal coffee roaster | The sensors monitor the weight of incoming green coffee and outgoing roasted coffee, improving process quality and the overall efficiency of the plant.
- Weighing of silos for ground coffee storage | Monitoring the weight of ground coffee inside the storage silos and transmitting the data to the management software, in order to improve and keep product traceability under control.
Weight monitoring on the loading hopper and destoner of an artisanal coffee roaster
Requirements
To monitor the weight of incoming green coffee and outgoing roasted and cooled coffee, in order to accurately measure the weight loss of the beans during the roasting process.
Accurate monitoring of this value is essential to ensure process repeatability and the quality of the final product.
Focus
During roasting, coffee undergoes a significant weight loss due to two factors: the evaporation of the water contained in the green bean and the loss of organic material, namely the silver skin that separates from the beans during the process.
This reduction, known as weight loss or roast loss, typically ranges from 12% to 20% of the initial weight, depending on the bean variety, origin and roasting profile.
The weighing system must be fast and accurate, while also requiring minimal installation space and integrating perfectly with the production control software developed by IMF.
Our Solution
For the weighing systems installed on the loading hopper and the destoner, we used:
- 7 FCOL bending beam load cells;
- 2 TLS485 weight transmitters;
- 2 CASTLTAST polycarbonate enclosures with keypad for the TLS485 weight transmitter.
How Does it Work?
The monitoring process takes place in two consecutive stages, with the load cells installed at two different points of the system:
- 3 upstream of the coffee roaster, on the coffee loading hopper;
- 4 downstream of the process, on the destoner, for the roasting and cooling stage.
The load cells are mounted on raised plates and fixed to the frame using two M12 screws. At the same time, each load cell is connected to the destoner by means of a threaded rod.
The three load cells installed on the loading hopper measure the weight of the incoming green coffee and transmit the value to the PLC as the initial reference value.
The coffee beans are then roasted and cooled before reaching the destoner, where impurities are removed.
Focus
The destoner is a machine that uses gravitational separation and performs two functions simultaneously: conveying the roasted beans from the cooling tray discharge to an elevated hopper, while at the same time removing heavier impurities.
Thanks to the airflow generated by the machine, the lighter coffee beans are lifted, whereas the heavier impurities fall by gravity into a dedicated collection container.
At the end of the cleaning process, the four load cells installed on the destoner measure the new product weight and transmit the value to the TLS485 weight transmitter which, in turn, sends the data to the PLC controlled by the management software. This enables the software to verify that the weight variation before and after roasting remains within the expected parameters.
The software compares the weight value of the green coffee with that of the roasted coffee and calculates the percentage weight loss.
Added Value
- FCOL load cells are compact and robust, making them ideal for accurate weighing with a very fast response time. Fast and accurate measurement is essential for quality control, production traceability and safe transfer to storage.
- The TLS485 weight transmitter applies a digital filter that reduces the effects of the mechanical oscillations typically generated by moving machinery. It provides stable and accurate data even during loading and unloading operations.
- The TLS485 weight transmitter perfectly integrates the load cells with the management software by transferring data and allowing the measured weight to be displayed on devices located remotely from the machine. This turns the destoner into a central point for data monitoring and increases the overall efficiency of the plant.
- Accurately measuring and monitoring the weight loss caused by roasting means verifying that the process is operating correctly. Depending on the variety, coffee beans contain different amounts of water and organic material; consequently, the weight loss varies according to the type of bean.
2 – Weighing of silos for ground coffee storage
REQUIREMENT
To measure the weight of the ground coffee contained inside each silo, in order to monitor the quantity of product loaded into and discharged from the silo.
The system must operate in a working environment with a potentially explosive atmosphere classified as ATEX Zone 2/22 and interface with the dedicated management software developed by IMF.
Our Solution
For each circular-section silo, we used:
- 3 FCAX 500 bending beam load cells, ATEX certified;
- 1 TLM8 Profinet/IO weight transmitter;
- 1 CASTLM8I enclosure, AISI 304 stainless steel X version, ATEX certified, for the TLM8 weight transmitter.
How Does it Work?
The three load cells are installed at the bottom of the silo and fixed to a carbon steel supporting structure.
The load cells measure the weight of the product inside the silo and transmit the data to the TLM8 weight transmitter, installed inside the CASTLM8I enclosure near the weighing system.
The weight transmitter sends the data via the Profinet/IO fieldbus to the PLC, which is located far from the weighing system.
The PLC then interfaces with the management software, which records the data in order to track all product loading and unloading operations.
Added Value
- FCAX load cells, integrated into the management software, are an excellent alternative to installing multiple rotary level sensors for starting and stopping product loading. A rotary level sensor only indicates the physical filling level of the silo, whereas the load cell continuously monitors its weight.
- The TLM8 weight transmitter features integrated diagnostics. It monitors the connection status of each individual channel and detects any malfunctions, errors or failures affecting the load cells. Process monitoring and management operations are therefore simplified.
- The system perfectly integrates the weighing functions into the logic of the software developed by IMF and controlled by the PLC.
- The recorded weighing data improve product traceability, making it possible to promptly identify any issues, ensure product quality and optimise logistics.
