Pin Type Barbed Boiler Water Wall With Refractory Coating NDT

Pin type water wall

Also known as barbed water wall.It is in accordance with the requirements that welding a certain length of round steel at the surface of the light pipe, then the refractory coating can be firmly laid on the water wall by using of pins, so that to form a fire belt, liquid slag discharge furnace slag pool and slag melting section, and the cyclone furnace of the cyclone cylinder. The water wall of inner threaded pipe is a pipe with single or multiple spiral grooves on the inner wall of the pipe. Internal threaded tubes are used in the high heat load zone of once-through boilers,sub critical parameters and forced circulation boilers or in the water wall sections with high vaporization rate. When the working fluid flows in the inner threaded tube, strong disturbance occurs, which causes the water pressure in the steam water mixture to the tube wall and forces the bubbles away from the wall to be carried away by the water, thus destroying the formation of the wapor film, preventing the boiling heat transfer from deteriorating, and lowering the temperature of the tube wall of the water wall panel.

Water wall panels are the main heating surface of boilers, composed of numbers of rows of steel tubes, arranged around the boiler corner. Inside is the flowing water or steam, and the outside accepts the heat of the flame in the furnace of the boiler, mainly absorbing the radiation heat of the high temperature combustion products in the furnace. The working fluid rises in it and evaporates by heat.

The full name is water wall tube, old name is water-cooled wall,also called riser. Usually laid vertically on the inner wall of the furnace, they are used to absorb the radiant heat by the flame and high temperature flue gas.They are the main form of heating surfaces for the various modern boilers, also the basic parts of water circulation circuit. For they have the functions of cooling and protecting the furnace wall, so called water wall panels.

Classification

If according to the structure type, there are three main types: bare tube type, membrane type, and prick tube type.

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