American-made Diedrich Roaster coffee roaster introduces infrared coffee roasting technology

American Diedrich Raoster

General gas-fueled bean dryers use open fire to heat air or inner pot (drum), metal heat conduction and hot air to bake coffee, which can be divided into three styles: direct fire, semi-hot air (semi-hot air) and full hot air. Although it is rare for domestic infrared heaters (Infared Burner) combined with steel plate heat exchangers (Heat Exchange) to bake beans, the IR series of Diedrich Roaster infrared heaters has been popular in the United States for 30 years. Due to relatively less gas consumption and less exhaust emissions, the number of users in Taiwan is increasing this year.

This machine uses infrared light not to heat the surrounding air, but only to bake coffee according to the characteristics of dark objects. This is like the fact that sunlight passing through the atmosphere does not make the air generate heat, but must shine on the entity to generate heat. Although the Diedrich Roaster IR series also uses gas, it uses infrared as the main heat conduction medium, so it has different designs and can be divided into three parts:

1. An infrared heater with two pieces of ceramic at the bottom

2. steel plate heat exchangers are installed on both sides of the inner edge of the furnace wall.

3. There is a hot gas corridor on both sides of the inner edge of the furnace wall and in the middle of the inner pot.

The gas firepower is directly sprayed on the ceramic infrared heater, because the heat resistance of the ceramic piece is very high, and the gas is burned completely, the amount of waste gas can be reduced. The infrared ray produced by the ceramic plate due to high temperature does not heat the surrounding air, but the steel plate heating exchangers on both sides of the inner edge of the furnace wall receive the infrared radiation from the hot ceramic plate, which makes the steel plate heat transfer to the clean air between the furnace wall and the inner pot, and sends the hot gas into the drum to provide 70% of the heat convection (Convective Heat) needed for baking. In addition, when the gas firepower heats the ceramic plate, it also heats the drum, providing 30% of the metal heat conduction of baked beans.

In the traditional bean dryer, the greater the firepower, the higher the temperature. If the firepower remains unchanged, the larger the throttle, the furnace temperature will decrease, but the smaller the throttle, the furnace temperature will rise. However, the Diedrich Roaster IR series, whose firepower affects the furnace temperature, does not seem to be as sensitive as the traditional bean baking machine, but it can provide a more stable baking temperature because the heat conduction medium is not as direct as the open fire.