Anti-failure structure for cast iron air preheater and key process thereof

Abstract

The invention relates to an anti-failure structure for a cast iron air preheater and a key process thereof, which can slow down failures such as thermal stress cracking, stress corrosion cracking, erosion corrosion, deformed sealing leakage and the like. A major structure comprises a shell, an elastic sealing system and cast iron fin-plate heat exchange elements, and the anti-failure structure is characterized in that: sponge type metal wires are filled in a flue gas inlet end to enlarge heat-exchange areas, protect fins against the erosion of flue gas, obstruct granular impurities in the flue gas, homogenize inlet airflow and replace and clean conveniently; a primary seal between two flows consists of a concave-convex groove, a wavelike elastic leaf metal on the groove bottom and heated expansion bars filled in the groove, a planar auxiliary seal and a sliding sleeve auxiliary seal in the middle of a fin plate are arranged additionally to form a set of high-elasticity and fluctuation-resisting compound seal system; a gradient area type flow channel for supplementing the increase and decrease in the two flows enables the pressure of both sides of the fin plate to be balanced and maintains kinetic energy; and the manufacturing process for arc corners and the fin plate at the periphery of the flow channel improves the performance of heat deformation cracking resistance and erosion resistance of the cast iron air preheater. New products are particularly suitable for preheating air in heating furnaces.

Description

1. Technical field [0001] This technology invention patent is about the anti-failure structure and key technology of cast iron air preheater, which belongs to the high-efficiency heat exchange and energy-saving equipment of heat exchange special equipment in mechanical equipment engineering. Specifically, it can be used in the heat exchange requirements of petroleum refining and chemical industry, coal chemical industry, chemical fertilizer, air conditioner, air cooling, power facility equipment, etc., including application methods such as heating or cooling the medium, especially suitable for flue gas waste heat of petrochemical heating furnaces Recycling equipment allows the combustion air to achieve the purpose of preheating. 2. Background technology [0002] The waste heat recovery equipment of heating furnace flue gas is tube type (spoiler), heat pipe type, water heat medium, plate type, cast iron type and other air preheaters. They have their own characteristics. Gener...

AI Technical Summary

Problems solved by technology

The thermal efficiency reduction of the heating furnace due to erosion corrosion and thermal deformation cracking may make the temperature of the low temperature section lower, which is more likely to cause dew point corrosion, forming a vicious circle

At present, the domestic ND steel (09CrCuSb) has good resistance to sulfuric acid low-temperature dew point corrosion, but the material cost is relatively high

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