Chocolate is one of the most energetic foods, but people love it for its taste and "emotional boost". These properties are developed in "power-hungry" processing operations, especially for the processing of raw material (chocolate) and the preparation of the final product. Therefore, energy efficiency has become a key topic in the engineering and manufacturing activity of SACMI Packaging & Chocolate, according to Franco Lumini, Corporate Technical manager of the Italian company. "Our business is focused on the design of equipment and the assembling and final testing of production lines. Our in-house energy consumption is limited," he explained, "while energy efficiency is a critical issue for our customers, who operate their plants intensively with massive power consumption. Hence, our commitment to review all our projects very accurately to guarantee the sustainability and optimization of energy consumption."
Today, SACMI Packaging&Chocolate and its brands offer machines and full lines for chocolate processing and molding (Carle&Montanari), primary packaging wrapping (Carle&Montanari) and flow-pack (OPM) lines, and solutions for secondary packaging (OPM) in different food and non-food industries. The company name itself highlights the strong focus on chocolate and packaging: the factory in Rozzano (near Milan) ships machinery and lines for the entire processing cycle, from raw to semifinished materials, up to the finished product shaped into blocks, bars or pralines, plus primary packaging lines for wrapping and flow-pack operations, and secondary packaging with machines for cartons and trays.
The transformation of raw material into chocolate is executed on refiners that achieve very high electric consumption levels, driven by motors from 90 to 132 kW. Refiners work continuously with a capacity of up to 1,500 kg/hour. The resulting product is then processed and shaped in the conches, where the product magnifies its smell and taste, and is added with the final ingredients; the conches are equipped with motors from 110 to 160 kW. The conches process 6-ton batches for periods from 5 to 8 hours according to the type and quality of chocolate. A mid-sized line processing 2-3 tons of chocolate per hour is made up of a couple of refiners and 4-5 conches, with total installed power exceeding 1 MW.
For ten years now, with the launch of the new series of machines (HFI refiners, Homega and Alpha conches), SACMI Packaging & Chocolate has been focusing on energy saving.
In the early 2000's, the company pioneered the use of IE3 efficiency class motors as standard, but the market was still "cold" in the propensity to invest more resources in exchange for greater energy efficiency. "Even the big US corporations with carbon dioxide reduction targets normally stepped back when they were presented with an offer that promised better energy performance at a slightly higher price," Lumini said. "This attitude has changed radically in recent years and companies are now considering high-efficiency alternatives with greater interest, looking beyond the short-term impact of the initial investment”. The focus on sustainability and environmental awareness have certainly increased, especially for environmental safeguard and the fight against climate change. In the US and Europe, new regulations and corporate policies are aimed at the reduction of energy consumption and CO2 emissions, supported by acceptable ROI within up to three years.
The designers at SACMI Packaging & Chocolate have adopted the synchronous reluctance motors SynRM IE5 from ABB. The SynRM IE5 motors have proved to be the ideal solution for the conching process, where the product is worked for several hours.
In this period of time, the motor runs at different loads and speeds. The data submitted by ABB "show that IE5 motors are more effective working at partial load and speed; therefore, the variable reluctance motor offers a much better solution than the conventional asynchronous 3-phase motors" Lumini said.
Based on the analysis of a typical conching cycle for high-quality dark chocolate produced in a high-intensity cycle (approx. 7,000 hours/year), replacing IE3 motors with IE5 delivers a 3-4% saving on electric current, while reducing CO2 emissions by as much as 22 tons annually (or 2.83 tons of oil equivalent).
ABB's help was essential for this type of calculation, Lumini said. "Taking measurements on industrial machinery like ours is a difficult task, because the properties of the material processed significantly affect the workload and the energy consumption. Even with identical machines, the results cannot be compared if the batches consist of raw materials with slight differences. ABB has provided us with internal data from their laboratory about the energy efficiency of IE3 and IE5 motors at partial load and/or speed. With reference to a typical conching cycle, we have managed to calculate potential saving under the same operating conditions."
The next step in the ABB/Sacmi partnership will be the setup of a test bench for benchmarking tests that, according to ABB, will show much more significant economic savings than those estimated so far. The test bench will be developed in ABB's new OEM HUB located in the Vittuone factory, to support Italian and South European OEM customers in the development of their applications.
The ABB package comprised of ACS880 drive and SynRM IE5 motor is the ideal solution to ensure the best performance of an application. A conch recently shipped to Poland has reached twice the nominal speed, a result that cannot be attained with conventional synchronous motors. "Except for customers with limited technical resources, now we normally submit offers including energy saving as an option, and the number of installations is growing," Lumini concluded. "Our industry is increasing the focus on sustainable packaging, driven by the big issue of plastics and waste reduction; therefore, the attention of media is stronger on this aspect rather than on energy saving. However, we see an increasing sensitivity to greater energy sustainability. So, we will keep focusing on the energy efficiency of our machines, both for electric motors and for the heat transfer flows inside the machine, which represent a large portion of energy consumption in our lines. For this reason, we have also adopted water-cooled motors both for the conches, to reduce the heat released into the factory environment, and for some models of refiners.
We are confident in the collaboration with ABB and the next step with benchmarking tests in their OEM HUB. With these tests, we will simulate a full conching cycle with different motor types, to validate the calculations based on laboratory data; once we have validated this method, we can be more effective in promoting the high-efficiency solutions included in our portfolio, standing out as an innovative and sustainable company”.