Boiler Tube sliding block, also known as Sliding pair, is composed of two components, which can only move in a certain direction. It has the function of keeping the tube platen flat in the platen superheater and preventing the tube from being out of line and dislocated and the formation of coke residue. The sliding pair is generally made of ZG16Cr20Ni14Si2 material.
The sliding block is used for the superheater. Different superheaters use different sliding blocks. The sliding block considers the relative thermal displacement factor. The vertical superheater adopts the L-shaped sliding sliding block. The sliding blocks are not welded to each other, which can realize the vertical direction. Swipe up freely. The horizontal superheater adopts M-type sliding block. The weight of the pipe is transferred to the end pipe through the M-type sliding block, the M-type sliding block is welded on the corresponding lower row of pipes, and the upper row of pipes is placed on the M-type sliding block, so each pipe can slide in the horizontal direction .
Superheater is a device that heats saturated steam into superheated steam with a certain temperature. After the saturated steam is heated into superheated steam, the work ability of the steam in the turbine is improved, that is, the useful enthalpy of the steam in the turbine is increased, thus improving the cycle efficiency of the heat engine. In addition, the use of hot steam can also reduce the steam turbine exhaust humidity and prevent the turbine blades from being corroded, creating favorable conditions for further reducing the steam turbine exhaust pressure and safe operation.
The superheater tube wall metal bears the highest temperature in the pressure parts of the boiler, so high temperature resistant high-quality low-carbon steel and various chromium molybdenum alloy steels must be used, and sometimes austenitic chromium nickel stainless steel is used in the part with the highest temperature. During boiler operation, if the temperature borne by the pipe exceeds the allowable temperature limit of the endurance strength, fatigue strength or surface oxidation of the material, accidents such as pipe bursting will occur.