The principle of the coffee roaster, what is the basic structure of the coffee roaster?

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The purpose of coffee roasting should be to find out the coffee beans with different treatments in different regions, which belong to its most appropriate [roasting degree].

Although roasting is the process of heating and scorching raw coffee beans, the real goal should be to create its own baking degree according to the different characteristics of raw beans and guide it to exude a unique flavor.

What kind of ascent curve should be used? Stop baking at the right time to give different coffee beans the best quality. And the tool used to roast coffee beans is the roaster!

Generally speaking, the roaster can be divided into direct fire type. "hot air type" and "semi-hot air type"

Most people see that the volume of the roaster for business is very huge, and it is even more difficult to understand the internal structure and principle.

The main heat source is at the bottom of the drum, which is continuously heated after pouring into the raw beans. The heat source is brought out from the exhaust hole on the left to form a moving line. When the coffee beans are roasted, they are poured into the cooling tank to cool down.

On the surface, the coffee roaster seems to be very complicated, but in fact, the structure is relatively simple. The roaster is composed of raw bean holder, drum, dust collector, dust collector, cooling tank and so on. The whole baking process of raw beans turning into ripe beans is mainly controlled by control panel, adjusting turntable, sampling spoon, baking / cooling switch and so on. Of course, good or bad roasting requires some experience and skills. This only belongs to the category of human level experience. Here we only focus on the main parts of the coffee roaster to explore its function.

Air valve:

The main functions of the gas valve are as follows: the exhaust function of waste such as smoke and broken layers, providing the necessary oxygen during bean combustion, and adjusting the heat in the drum. Basically, the air valve mainly has the function of "the temperature of the drum rises when it is opened and decreases when it is closed". After putting the raw beans, immediately enter the "steaming mode" (need to close the gas valve) to homogenize the beans, which is also one of the important functions of the gas valve.

The air valve has exhaust and cooling sharing type, and the two separate types. The shared type requires a "baking / cooling switch" to control the baking of raw beans and the cooling of cooked beans out of the tube.

Roller:

The drum structure of direct fire type and semi-hot air type is very different, but the basic condition is that the stirring blade which can bake beans evenly is also suitable for rotating speed. If you put as many raw beans as the capacity of the roaster, it will cause uneven baking and difficult exhaust. Most of the causes come from the structure of stirring blades. The roaster pushes the beans to the front of the drum according to the centrifugal force generated during rotation, so that the beans are fixed in a ball. In general, it is best to bake up to 80% of the beans.

Smoke exhaust equipment:

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.