A recipe for success: the benefits of motors, drives and automation in the bakery industry
Article by Fernando Garza, OEM Segment Sales Manager,
Food and Beverage, ABB Drive Products
Fernando Garza, OEM Segment Sales Manager, Food and Beverage, ABB Drive Products, discusses why bakeries should adopt motors, variable speed drives and PLC automation to overcome challenges related to sustainability, reliability and safety.
Electric motors power many of the vital processes in bakeries – from mixing, forming and proving to conveying and packaging. However, most bakeries still control the speed of their motors via mechanical throttling. For example, this could involve changing the tension of a conveyor’s pulley system to alter the motor’s speed. This approach is outdated and inefficient, since the motor runs at full speed even when it doesn’t need to.
The equipment used in baking is also traditionally very energy intensive. For example, bread ovens are often designed to maximize product quality and productivity, without concern for the energy used. As energy costs remain high, improving energy efficiency should be a top priority for bakeries.
With stricter food and personnel safety standards and increasingly stringent environmental regulations on the horizon, the time to invest in new equipment is now. As the global population grows, this will enable bakeries to keep up with demand for products while ensuring they meet new energy efficiency regulations.
Baking smarter, not harder
So, how can bakeries improve their processes? The answer lies in using variable speed drives (VSDs) – also known as variable frequency drives, or just drives – and programmable logic controllers (PLCs).
Rather than running at full speed all the time, drives match a motor's speed with the task's requirements, significantly reducing the energy required. When no drive is present, a motor will always run at its full speed. Therefore, to slow down the motor, bakery operators traditionally apply mechanical throttling downstream to limit the output. This is like trying to slow down a car by applying the brake while your foot remains on the accelerator. A better method would be to simply adjust your throttle pedal – and this is essentially what a drive does. In fact, drive-controlled motor systems offer 20 to 60 percent savings compared to a system without a drive.
Drives can be fitted to a variety of bakery equipment: mixers, pumps, extruders, cutters, conveyors and fans are just a few examples. This means a range of processes like mixing, proving, baking and freezing can all be done more easily, efficiently and safely.
Although many bakeries already use high-efficiency motors, they can achieve greater energy efficiency by upgrading them further. Bakeries now have the option of upgrading to ultra-efficient IE5-rated synchronous reluctance motors (SynRM). Using IE5 SynRM motors can yield energy savings up to 40 percent greater than IE3 motors. Bakeries can also benefit greatly from the use of modular PLCs – small computers that enable the automation of industrial processes. A good example of this is the use of power controllers in electric ovens.
A series of thermoregulators – one for each area of the oven – can provide data to the PLC, which adjusts the power provided to the coils to ensure an even heat distribution. This approach delivers a more consistent product and saves power. PLCs can also automatically control the start-up/power-down process and ensure safety during the oven’s operation.
Many bakeries still control conveyors manually, so switching between recipes or products is slow. The use of PLCs can greatly speed this up, increasing the bakery’s overall productivity. The human-machine-interfaces (HMIs) provided by modern drives also make it easy for operators to automate recipe changes.
Precise process control saves dough
Using a drive also enables greater precision and control over processes, since it can match the motor speed to the exact requirements of the specific application or recipe. This results in a more consistent product – the mixing, texturing and shaping processes are all refined. This precision also reduces the volume of materials like dough that is wasted during the process.
This extends to water, which is both a key ingredient used during baking and a vital resource for cleaning machinery. Some bakeries even have recirculating water features for cleaning pipes and components. Therefore, when attached to these water pumps, the enhanced precision provided by drives can save on this important resource.
Using drives and PLCs makes a bakery more flexible in terms of output. This is particularly useful for meeting seasonal changes in demand. For example, some countries consume more bread at the beginning of the year when it is colder. A bakery using drives could then reactively ramp up the speed of motors throughout its processes to increase output.
An example of this in practice is The Village Bakery based in Wrexham, Wales. It used outdated technology to control the speed of its conveyors to divide the dough and grease baking tins. This led to issues with precision and wasted energy and material. After fitting a VSD to the conveyors, the bakery managed to save 27 percent on energy costs and used 10 percent less greasing agent on its baking tins, resulting in savings of £20,000 per year.
Product quality and reliability on the rise
Product quality can also be improved by using automation to directly regulate cooling water temperature and avoid unwanted temperature spikes. Drives and PLCs, such as those from ABB, enable operators to supervise or remotely start/stop different processes. Furthermore, powertrain data collection combined with motor sensors provides operators with useful insights into energy usage, equipment status and overall equipment condition.
Drives can also reduce the mechanical stress on motors and driven equipment to significantly improve reliability. Advanced starting, stopping and protection functions – such as smooth-start and speed compensated stop for conveyor systems and cavitation and dry-run detection for pumps – mean lower maintenance costs and less equipment downtime.
Cavitation when pumping liquids – the formation and collapse of bubbles that damage pumps and pipes in a remarkably short time – is another problem in the bakery industry. It reduces equipment reliability and can affect the quality of some liquids, especially milk. Cavitation occurs when there is a loss of pressure on the inlet side of the pump.
Anti-cavitation software built into all-compatible drives, such as ABB’s ACS880 industrial drives and ACS580 general purpose drives, can monitor any changes and make instant adjustments to reduce the pump speed to prevent cavitation. When the inlet pressure recovers, the drive automatically ramps the pump speed back up again.
Safer equipment = safe food and safe employees
All-compatible drives from leading manufacturers also come with a suite of safety features. For example, a safe torque off (STO) feature prevents any motor from starting unintentionally should a piece of equipment malfunction or an accident occur. This protects bakery personnel and enables the affected machine to be safely opened, inspected and maintained.
Any environment that is particularly dusty can pose a significant safety risk. If an excess of flour clogs up a piece of equipment and causes the motor to overheat, for example, it can potentially lead to an explosion. To counteract this, industrial and general-purpose drives are available with ATEX-compliant safety features. They disconnect the motors from their power supplies if they are at risk of overheating.
Network harmonics – sometimes referred to as “electrical pollution” – are also a common challenge in bakeries. Harmonics are generated by non-linear loads like LED lighting, computers, uninterruptable power supplies and some drive technologies. A high level of harmonics present in the system pollutes the electrical network of the bakery and can damage sensitive electronics, cause trips, and overheat equipment – increasing fire hazards. Ultra-low harmonic (ULH) drives have a built-in filter and other features that reduce harmonic pollution. Less deviation in current supplied to the motor also enables it to run more efficiently and increases the bakery’s productivity.
Further, PLCs add traceability to production, for example, by providing a means of quality management of food from the start to the end of the entire baking process. Food safety is thus enhanced through quality control management via automation.
Serving up success
Bakeries can benefit greatly from investing in drives, more efficient motors, and PLC automation. These technologies boost a bakery’s efficiency, precision and safety – in turn, cutting costs and increasing productivity. By adopting more energy-efficient and sustainable solutions, bakeries can keep up with demand while also combatting energy costs and meeting new regulations and environmental standards.
For further information, please visit: new.abb.com/drives/segments/food-and-beverage/bakery.
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