Factors to Be Considered in The Selection of Lining Materials for Circulating Fluidized Bed Boilers
August 01, 2018
Factors to be considered in the selection of lining materials for circulating fluidized bed boilers
The furnace of a circulating fluidized bed boiler operates under a special hydrodynamic characteristic, and fine particles are transported through the furnace at a gas flow rate exceeding the average particle end velocity, while sufficient particles are returned to ensure uniform temperature distribution in the furnace.
1. The furnace of a circulating fluidized bed boiler has a certain amount of solid particles, and the particle size of these particles is usually in the range of 0.1 to 0.3 mm. And the solid particles mainly include the following categories:
(1) sand or gravel (when burning low-ash fuel such as wood chips);
(2) Fresh or reacted limestone (when burning high-sulfur coal or when desulfurization is required);
(3) Coal ash (when burning high or medium ash coal without desulfurization).
2. The performance of CFB lining materials should have the following requirements:
(1) The inner circulation vortex type turbulent bed lining requires high wear resistance, high temperature resistance and erosion resistance;
(2) The lining of the inlet section of the high temperature external circulation separator requires high wear resistance and high temperature resistance;
(3) The inlet of the medium temperature external circulation separator requires high wear resistance and high temperature resistance;
(4) Medium and high temperature external circulation separator cylinders require heat resistance, heat preservation and low thermal inertia;
(5) Ignition combustor flue, requiring heat resistance;
(6) The suspension chamber requires high heat resistance, wear resistance and low thermal inertia.