The water-cooled wall of the water tube boiler is placed on the inner wall of the furnace, and is arranged closely adjacent to the furnace wall, and is arranged substantially in a vertical manner. For boilers below subcritical pressure, the water wall is mainly used to absorb the radiant heat of the high temperature flame in the furnace, so that the working medium (water) entering the pipe generates steam. In the furnace design, in addition to meeting the fuel combustion conditions, the heat absorption of the water wall is sufficient to reduce the outlet temperature of the furnace to the softening temperature of the fuel residue to prevent coking of the heated surface of the furnace outlet.
First, the light pipe water wall
The inner and outer walls are composed of smooth seamless steel tubes and have no other features.
Second, the pin type water wall
For furnaces burning low-volatility fuels, in order to maintain a high-temperature flame in the combustion zone to facilitate fuel combustion, it is necessary to lay a certain number of insulation zones on the furnace wall of the burner arrangement area. The refractory belt is generally welded with a refractory material such as chrome ore on the water wall tube.
Third, the internal thread tube water wall
For the subcritical pressure natural circulation and control cycle boiler, in order to prevent the membrane boiling from prematurely occurring, the heat transfer of the steam-water mixture is delayed, and the high heat load area of the burner is arranged in the furnace, and the internally threaded tube is often used instead of the smooth inner light tube. To make water walls.
Fourth, membrane type water wall
Most modern boilers use this structure, and so are the FANGKUAI Boiler same. This is because the water wall of the boiler of this structure is a continuous steel structure, avoiding the contact between the brick wall and the prefabricated (refractory) material and the flame surface, reducing the heat load and weight of the brick wall and the heat insulating material, and facilitating the sealing of the furnace ( Reduce air leakage). At the same time, a smooth and low temperature metal surface is beneficial to reduce the possibility of coking in the furnace.
