Probat announces Px 120 drum roaster

In 2018, German roaster manufacturer Probat celebrated its 150th year in operation. In 2019, the company will continue its reputation for quality and longevity. Thomas Koziorowski, Executive Vice President Product Technology and Research and Development at Probat, tells Global Coffee Report that in 2019, the roaster manufacturer will launch several new technologies and innovations. At the forefront of Probat’s plans is the release of its Px 120 drum roaster in October. “The Px 120 is our line of new drum roasters designed for the specialty coffee industry,” Koziorowski says. “Many businesses in this field want to be able to show what they do and how they do it to their customers, so we have designed a machine with a clean look where the process [of roasting coffee] is clear and visible.” The Px 120 line is targeted to mid-sized specialty coffee roasters, with a batch capacity of 60 to 120 kilograms, roasting time of six to 20 minutes, and production capacity of 480 kilograms per hour. Due to the machine’s clean look and visible processes, Koziorowski says it is well suited for larger roasteries to also use in showrooms. Despite Probat’s emphasis on the Px 120’s aesthetics, Koziorowski says it’s the machine’s technical advancements that make it shine. “We have seen that there is demand from these industries – specialty and showcase roasting – for a machine that allows them to display what they do, but still has the full functionality you’d expect from an industrial roaster,” Koziorowski says. In order to meet the needs of the specialty coffee industry, Probat designed almost 80 per cent of the machine’s components new over a year-long development process. “Usually when new roasters are built, existing equipment is simply updated. The Px 120 contains fully new components that really take advantage of the possibilities offered by new developments in roaster technology,” Koziorowski  says. “The system must be designed to work in an optimum way with today’s features and possibilities, such as better control of drum speed and other factors.” The Px 120 drum roaster has frequency converters installed on all drives used to control its flow rate and drum rotation speed, providing the roaster with greater control over variables such as speed and temperature. A drum roaster operates by producing heat in a specially designed oven and burner system underneath the drum of the machine. The hot air is sucked through the back wall of the drum and guided around the drum wall to roast the coffee beans. Koziorowski says most roasters expend a lot of energy gathering room-temperature air and warming it to the desired heat. To reduce energy usage, the Px 120 recirculates already warmed air back through the burner system to be reheated. “Typically, the burner in a drum roaster is working with fresh air at approximately 20°C, and heating it up to 500°C. The Px 120 recirculates already heated air, which is around 200°C. This means the burner has to heat up the air 180°C less,” Koziorowski explains. The use of recirculated air, however, brings its own challenges. During the roasting process, the coffee bean doubles in volume, causing its dried skin to come free as chaff. These chaff particles have to be removed from the recirculated air to prevent it from building up within the system. To ensure that hot air is the only thing recirculated through the drum roaster, the pre-heated gases are run through a cyclone system to separate chaff and dust particles from the air before it enters recirculation. “While designing the Px 120, we used computational fluid dynamics (CFD) analysis to develop highly efficient cyclones to keep the machine and the air it is recirculating clean,” Koziorowski says.
CFD is an analytics system that simulates the flow of fluids – such as liquids and gas – through parts of the system and renders them as a fluid dynamic calculation, similar to a 3D drawing. While designing the Px 120, this technology also allowed Probat to view how the air stream would run through the roaster and reduce its energy and pressure losses. “Optimising pressure losses in the system provided us with more flexibility in what components we used in the machine, resulting in a range of benefits,” Koziorowski says. “[For instance,] when you have less pressure losses in the systems, you can use smaller fans and motors which saves energy.” Koziorowski believes of all the new equipment and technology incorporated into the Px 120, it will be the machine’s new control system that will leave the greatest impression. “The new control system will provide the operator with a clear view of relevant data,” he says. “The roasting curve is clearly displayed, allowing them to see what is happening within it at real time. “It will also allow [users] to easily change factors such as temperature and air flow volume to create roasting profiles tailored to their own preferences.” The control system is capable of external network connectivity and functionality, allowing for easier handling, remote service, and direct access from off-site locations. Koziorowski says Probat has even integrated a management level into the software that collects data related to key performance indicators. “While operators can use these new features to get the most they can out of the machine, managers can monitor energy consumption and other information related to management decisions,” he says. Though this new control system will be released in conjunction with the Px 120, Probat intends to include the software on all further product launches. Koziorowski also hopes to make the technology compatible with existing roasters. “In general, we would like to downsize this technology to be compatible with existing roasting equipment,” he says. “This is a functionality we would like to have linked to all of our digital services going forward.” For more information, contact www.probat.com