Kekai products

Solid fuel boilers differ from the others because their combustion is continuous, that is, once they are turned on, they only turn off when the fuel runs out or the air intake is completely cut off. Power regulation is done by varying the air intake. Currently there is a tendency to prohibit the use of coal, as it is the fuel that produces the most amount of CO2 per unit of heat, 9 however boilers with wood pellets are used, which is also a solid fuel.

As a liquid fuel, the only one in normal use is diesel. Gaseous gases are of two main types: natural gas and liquefied petroleum gases (butane and propane). The boilers work with a coupled burner that, by means of a fan, makes the proper mixture of air and fuel, and burns in the hearth. Both with liquids and gases, the operation of the boilers is intermittent, that is, the power regulation is done by starting and stopping the burner. There are burners called modulating that vary the power of the flame depending on the demand, regulating the fuel flow.

Series of candles of a boiler with atmospheric gas burner

There are also gas boilers with atmospheric burners, which do not require a fan; The gas flows under its own pressure, comes out under pressure through fine injectors and mixes with the air by venturi effect before reaching the burner itself. In these boilers the burner consists of a certain number of candles arranged in rows on a plane.

There are unit combustion appliances, such as butane gas stoves, called catalytic stoves. They have an acceptable performance, but they require air from outside for combustion and they produce a large amount of water vapor as a result (approximately 1.6 liters of water for each kilogram of fuel10), so they are not very advisable, as they add great amount of moisture to ambient air. Kerosene unit stoves are also used, with the same drawbacks, although with a slightly lower steam production.