An example that has already proven itself in practice explains the procedure for designing the electric heating system for a roasting machine with a batch size of 5 kg. This was equipped with a modern electric air heater. The functionality is visualized in the image below. The drum roaster is controlled via the parameters of temperature, the air volume and drum speed. The software of the roasting machine regulates the heating output and the exhaust fan in such a way that the roasting process exactly follows the speci ed temperature pro le of the roasting curve. The two blowers operate in a “master/slave” mode to ensure that there is always a negative pressure or a controlled draft in the roasting machine. The exhaust air blower works in master mode. The bean temperature, which is measured directly at the bean in the drum via a sensor, is decisive for temperature control. In addition, the outlet temperature is also monitored. This is measured before the exhaust fan. The hot air inlet temperature is also checked and measured on the air heater. In order to prevent overheating of the heating element even in the case of faulty operation, it is recom- mended to install an air ow meter or pressure sensor in front of the air heater. This ensures that su cient air- flows through the roasting machine before switching on the air heater. An important prerequisite for the feasibility of the process is the precise control of the air volume or the blower and the temperature of the air heater. Blowers and air heaters must therefore be selected that can be precisely controlled and regulated and matched to the speci c design of the roasting machine in terms of performance and dimensions. Mathematical Design of the Heating System In order to de ne the appropriate electrical heating system, the required heating output must be calculated in advance. The following variables are required as a basis for the calculation: „ Design,structureanddimensionsoftheroastingmachine „ Insulationoftheroastingmachineandtypeofinsulationmaterial,itsthicknessanditsthermal conductivity λ [W⁄m*K] „ Batchsizeinkilograms[kg] „ Maximumheatingtemperature(dependingonthedesignoftheroastingmachine)indegreesCelsius[°C] „ Temperatureontheoutputfanaftertheheatingphaseoftheroaster „ Maximumairvolume owV̇ instandardliterperminute[slpm] „ Approx.roastingtimeinminutes[min] The following graphic illustrates this example calculation:

As someone who has installed more than 50 coffee roasters in various European countries, this is the first thing I will tell you. You can find the best chimney and gas burner solution by following the questions below. Do you have neighbors who will be disturbed by flue gas? If you are going to start somewhere in the city center, you may need to buy an afterburner. This will not be necessary in areas far from settlements or where you have tolerant neighbors. However, keep in mind that roasting coffee produces a lot of smoke. I advise you to stay away from solutions such as smoke filters. It will cause you to pay twice for the same job. You can see the video of a customer who used afterburner after getting complaints from his neighbors with the smoke filter solution. Country: Norway For a good chimney installation, you can see the example of our customer from Berlin below What are the most important points in the chimney structure? - Double and insulated parts passing through the building wall - Having an openable lid for cleaning at the bottom Dätgen DB-1 Afterburner is working cleanly right after a German pharmacy (Apotheke).

Leister LE 10000 DFC Hot-air Electric In addition to their precise control and efficiency, Leister electric burners also offer other advantages for coffee roasting. They produce clean heat, free from combustion by-products and other contaminants that can affect the flavor of the coffee. This can result in a cleaner, more pure taste in the final product. Leister electric burners are also easy to maintain and clean, with no need for regular maintenance or cleaning of combustion chambers, burners, or flues, as would be necessary with gas-powered burners. This can save time and reduce maintenance costs for coffee roasting operations. Finally, Leister electric burners offer flexibility in terms of their placement and installation, as they do not require ventilation or a gas supply. They can be easily integrated into existing roasting setups or used in new installations, making them a versatile option for coffee roasters of all sizes and levels of experience. Overall, Leister electric burners offer a reliable, efficient, and versatile solution for coffee roasting, with precise control over the roasting process, clean heat, easy maintenance, and flexibility in installation. Dungs HeatEngine Point Burner Hot-air Gas One of the key advantages of the Dungs HeatEngine for coffee roasting is its advanced combustion technology. It uses a high-efficiency, low-emission burner that maximizes fuel efficiency and minimizes emissions. This can lead to lower operating costs and reduced environmental impact, which is increasingly important for coffee roasters who want to operate sustainably and reduce their carbon footprint. Another advantage of the Dungs HeatEngine is its precise heat control. It can modulate its heat output to match the specific needs of different coffee roasting profiles, allowing for more accurate control over the roasting process. This can result in a more consistent and repeatable roast, which is important for maintaining the quality and consistency of the final product. The Dungs HeatEngine is also easy to install and maintain, with a compact design and simple controls that make it easy to integrate into existing roasting setups. It requires minimal maintenance and has a long service life, which can help reduce downtime and repair costs for coffee roasters. Finally, the Dungs HeatEngine offers environmental and cost benefits compared to traditional gas-fired burners. It is highly efficient and produces fewer emissions, which can help coffee roasters reduce their carbon footprint and operating costs over time. Overall, the Dungs HeatEngine is a powerful and reliable choice for coffee roasting, with advanced combustion technology, precise heat control, ease of installation and maintenance, and environmental and cost benefits that make it a compelling option for coffee roasters of all sizes and levels of experience. Polidoro NP Low Nox Drum Gas The Polidoro NP Low Nox gas burner is a specialized burner designed for coffee roasting applications. It features advanced low-NOx combustion technology, which reduces nitrogen oxide emissions during the roasting process. This makes it an environmentally friendly option for coffee roasters who want to reduce their carbon footprint and minimize their impact on the environment. In addition to its low emissions, the Polidoro NP Low Nox burner is highly efficient and can provide precise heat control for coffee roasting applications. It is designed to be compact and easy to install, making it a versatile option for coffee roasters of all sizes and levels of experience. The Polidoro NP Low Nox burner is designed specifically for coffee roasting applications and is well-suited for use with a drum roaster. It is capable of producing a wide range of heat outputs to match the specific needs of different coffee roasting profiles, and it is highly reliable and easy to maintain. Overall, the Polidoro NP Low Nox gas burner is an excellent choice for coffee roasters who are looking for a low-emission, efficient, and reliable burner for their roasting applications.