Simple function description of each part of Italian coffee machine

Boiler:

At present, the popular coffee machine boiler is mainly made of copper and stainless steel, but some manufacturers also use copper alloy and copper plating.

The main characteristics of copper boilers are good extensibility (good elasticity when frequent alternation of hot and cold water) and fast heat transfer speed. It was widely used in early wineries, such as some spirits distillation equipment. Figure 1.JPG (17.84 KB)

Liquor distillation equipment

For the coffee machine, the speed of heat transfer will directly affect the overall heating uniformity, so copper naturally becomes the main material for making boilers. Now the cooking heads of some machines are also made of copper to facilitate the maintenance of effluent temperature.

Since stainless steel appeared much later than copper, the original coffee machine has always been made of copper. The main advantages of stainless steel are non-corrosive and durable. But it seems that stainless steel boilers are very expensive.

In addition to the boiler, there are two devices to maintain the normal operation of the boiler: high-pressure valve, low-pressure valve and discharge valve.

High pressure valve

High pressure valve is a safety device, mainly to protect the safety of operators.

Main principle: when the water in the boiler is heated to produce pressure, and the pressure in the boiler reaches the preset 2bar, the valve will be opened and begin to relieve pressure, in order to avoid excessive pressure and exceed the pressure limit of the boiler itself.

Low pressure valve

A low-pressure valve is a valve set to maintain the normal operation of the coffee machine.

Main principle: avoid low pressure in the boiler caused by temperature drop and air volume contraction in the confined space. When reheating, the air expands faster than the temperature of the liquid caused by the heat conduction of the metal, which makes the pressure sensing element misjudge the pressure in the boiler and stop heating.

Discharge valve

The discharge valve is at the bottom of the boiler, mainly when turning on for a long time, keeping the water fresh, cleaning the scale in the boiler, and repairing the machine, all the water in the boiler needs to be removed. At this time, all the water in the boiler can be discharged by opening the discharge valve.