Starting from the boiler, a detailed explanation of the coffee machine

1. Classification of boilers

There are three types of semi-automatic coffee machines on the market: mother-and-child boilers (heat exchange boilers), double boilers, and multi-boilers. Among the coffee machines we usually see, 8 out of 10 are mother-and-child boiler systems.

2. Working principle of mother-child boiler

The mother boiler heats the water to about 120℃, and heats the sub-boiler to about 90℃ through heat transfer, so it is called a heat exchange boiler. Since the heating element is on the mother boiler and the water temperature is dominated by the steam pressure of the mother boiler, the extraction temperature is not easy to control. Generally, coffee machines below 40,000 yuan are basically mother-and-sub boilers.

3. Working principle of double boiler and multi-boiler

The double boiler coffee machine has independent steam boiler and extraction boiler. The large boiler is responsible for steam and hot water for tea brewing, and the small boiler is responsible for hot water for extraction of the brewing head. The water temperature of extraction is not easily affected, which greatly ensures the extraction water temperature and steam pressure, and ensures the quality of the coffee produced.

A multi-boiler coffee machine is similar to a double boiler, except that each brewing head has an independent boiler, forming a three-stage heating system.

Both double boiler and multi-boiler coffee machines can set the extraction temperature at will by adjusting the temperature of the boiler, but multi-boiler coffee machines can control the temperature more accurately than double boilers, and can still achieve a constant temperature effect when producing a large number of products.

4. Boiler for household appliances

Most small household machines do not use water storage boilers, but add pipes to the heating element, and the water in the water tank enters the heating block for heating. Therefore, it is easy to cause insufficient steam when frothing milk.

5. Boiler material

Currently, the most popular coffee machine boiler materials are copper and stainless steel. The main features of copper boilers are good ductility and fast heat transfer. The heat transfer speed will directly affect the overall heating uniformity.

The advantages of stainless steel boilers are that they are not easy to corrode, are relatively durable, and are more affordable.

6. The influence of water on boiler

Generally, tap water is hard water. The calcium and magnesium ions in hard water will form scale in the boiler, causing the boiler to become blocked, malfunction, or even die, greatly shortening the life of the coffee machine. Therefore, in daily maintenance, it is necessary to regularly replace the boiler water, or add a water softener to reduce or even remove the calcium and magnesium ions in the water to extend the life of the coffee machine. Pay more attention to boiler protection and don't let the situation shown in the picture below happen to our machine.