With the serialization and functionalization of aluminum silicate fiber materials, the application fields of aluminum silicate furnace linings are becoming more and more extensive. How to determine its application fields has attracted widespread attention from design departments and users. Based on the basic regulations on the structural design of aluminum silicate fiber linings for flame heating furnaces and years of practical experience, the application of fiber linings is defined below for reference.
Design principles of aluminum silicate furnace lining
(1) Except for the smoke pipe, air duct and furnace bottom where flue gas is forced to flow, all other areas of the heating furnace can be lined with aluminum silicate fibers.
(2) The operating temperature of any layer of fiber lining must be at least 260°C higher than the calculated temperature of the hot surface of this layer.
(3) When the S content in the fuel exceeds 10×10-⁶ and the furnace lining adopts an aluminum silicate fiber structure, the hot surface of the furnace wall steel plate should be painted with a layer of anti-corrosion paint, which is suitable for 177°C environment. When the S content in the fuel exceeds 500×10-⁶, a gas barrier aluminum foil or stainless steel foil should be installed. The gas barrier layer should be located at least 56°C above the calculated dew point under operating conditions. The edges of the gas barrier layer should be overlapped, and the edges of the furnace lining and the puncture parts should be sealed to prevent corrosive gases from penetrating the furnace lining and condensing, and corroding the steel plates and anchors.
(4) When the heavy metal content in the fuel exceeds 100×10-⁶, all heating furnace linings cannot be made of soft fiber materials, but should be made of fiber unshaped materials, prefabricated blocks or other heavy insulation materials.
(5) When the pressure the furnace lining bears is greater than 0.8MPa, aluminum silicate fiber furnace lining cannot be used.
(6) Aluminum silicate fiber furnace linings cannot be used in the convection section equipped with soot blowers, steam spray guns and water washing equipment.
Aluminum silicate furnace lining composition materials
Aluminum silicate fiber materials can be divided into two categories in terms of form: one is shaped aluminum silicate fiber. At present, there are mainly aluminum silicate fiber cotton, aluminum silicate fiber blanket, aluminum silicate fiber board, aluminum silicate fiber special-shaped parts, aluminum silicate fiber paper, aluminum silicate fiber textiles and other deep processing products. The other type is amorphous aluminum silicate fiber, which mainly includes fiber castables, fiber plastics, fiber coatings, fiber spray coatings and other related products. From the use temperature of the product, the product can be divided into: type 1050 (use temperature 600~950℃), type 1260 (use temperature 950~1100℃), type 1400 (use temperature 1100~1350℃), type 1600 (use temperature 1100~1350℃) 1350~1400℃).
Anchors, so this type of furnace lining is only suitable for low-temperature furnace wall insulation.