- Time:Nov 02, 2022
The main purpose of lining the circulating fluidized bed boiler with wear-resistant refractory material is to protect the steel shell of the furnace body from being eroded and worn by the burning materials. The inferior coal burned by the circulating fluidized bed boiler has a high ash content and a large size of fly ash particles. The collision heat transfer of the inner heating surface and the inner lining and serious erosion and wear problems, the circulating combustion path of the burned material: coal powder (generally with a particle size of 0-10mm) and limestone powder are fed into the fluidized bed combustion chamber through the feeder (dense phase zone), where the fuel boils and burns. The flue gas rises and enters the cyclone separator through the dilute phase zone to the inlet of the separator, and the coarse particles sink through the return valve and return to the combustion chamber to be burned again. The flue gas carries the fly ash and ascends through the convection flue to enter the external heat exchanger. Refractory materials are mainly lined in the combustion chamber, ceiling, separator inlet, high temperature cyclone separator and return valve.
Taking a 220t circulating fluidized bed boiler as an example, under the working conditions of refractory materials in each part:
(1) Dense phase zone, the depth of this zone is (220-1530mm, length 2100mm sand-like medium (coal powder and limestone powder)) in this boiling zone, the pressure in this zone is 13818-20580pa, and the flue gas flow rate is about 1.2-1.8m , the normal working temperature is 820-900℃;
(2) In the dilute phase area, the area above the secondary tuyere is where the fine particles of fuel combustion are concentrated, where the solid material concentration is about 12-16kg·m-3, the flue gas flow rate is 1.2-3·-1, and the normal working temperature 930-980℃;
(3) In the furnace top area, the normal working temperature is 850-1100 °C, and the flow rate of flue gas at the inlet of the separator is increased by 18m·s;
(4) Cyclone separator, the normal working temperature is 850-930℃, and the flue gas flow rate at the cyclone outlet can reach 29m·s-1;
(5) The outlet main pipe of the cyclone separator, where the dust content of the flue gas is 70-530g·m-3, the normal working temperature is 850-930℃, and the maximum flue gas flow rate is 18m·s-1.
ZHENJIN REFRACTORIES is committed to one-stop general contracting services such as R&D and manufacturing, technical solution design, construction and supporting product provision of refractory materials for cement, lime, non-ferrous, steel, glass and chemical industries. The main product developed by the company is periclase-hercynite refractory bricks, magnesia-aluminum spinel bricks, and GUIMO abrasion resistant bricks all have good corrosion resistance, wear resistance, and excellent kiln-hanging skin. The products have been well received by customers.
