Introduction to the structure, working principle and circuit training of coffee roaster

Introduction to the structure, working principle and circuit training of coffee roaster

Raw beans in baking produce quite a lot of dust, broken layers, and silver skins, and dust collectors are the machines that collect these things. There is a horizontal pipe connection between it and the roaster, and then to the chimney outside the house. The curved part of the chimney will cause turbulence, so it is installed in a straight line as far as possible, so that the chimney extends to a considerable height. The chimney is not just a simple exhaust outlet, it is also its job to extract the air accumulated in the dust collector.

Cooling device:

If the beans are not cooled immediately after baking, the beans will continue to bake with their own waste heat, which will make the taste more bitter.

Firepower device:

The temperature of the roaster is controlled according to the firepower of the burner and the multiple adjustment of the gas valve. The firepower setting end depends on the gas pressure gauge, and the micro-adjustment depends on the gas valve.

First, when the preheating temperature of the oven is not enough, the coffee beans are immediately put into the oven, which prolongs the baking time. Therefore, the baking loss is large, and the color of coffee beans is light, which is due to the lack of heat and the lack of full coking of the skin, resulting in a lack of color and rough internal tissue.

Second, the temperature of the oven is too high, the hard skin is formed prematurely on the surface of the coffee, which suppresses the expansion of the internal tissue, and because of its fast surface coloring, the operator mistakenly thinks that the product has been baked and ends the baking ahead of time. The inside of this kind of bean is sticky and dense, it doesn't expand as it should, and it doesn't have a normal flavor.

Third, the gap is too long after preheating. Too much heat accumulates in the internal furnace which has been dry and hot for too long. As soon as the coffee beans enter the oven, all the heat sources concentrate on the surface of the beans at the initial stage of the baking process, forming too strong heat, and then the heat disappears and cools rapidly. The unstable temperature in the furnace makes the coffee beans difficult to ripen inside.

Fourth, the baking time is too much or not enough. The baking temperature and time should be adjusted according to the number of beans. A small number of baking silos have more space, and the metal conducts more heat radiation, so the temperature is lower, while when the quantity is larger, the temperature can be higher. The baking time also needs to be adjusted flexibly. The heating of beans in the oven is nothing more than the absorption of heat from the appearance and surrounding to the center of the beans, so the baking can be observed from the changes in the appearance of the beans.

In addition, the type and performance of the roaster will also cause the difference of baking time and temperature. The convection design of energy has been continuously improved from the direct-fired gas up-and-down fire mode to the electric heating mode which is now widely used. At the same time, the installation of fans can improve the stability of thermal convection, make the color of baked beans more uniform, and save electricity and baking time.