New NOF and Post Zinc Pot Cooler for Automobile Sheet Galvanizing Line Revamp

摘要

This paper takes an annealing furnace revamping project as an example for elaborating the remarkable role of 1500 embedded polycrystalline fiber module, the interlayer rollers, the mist cooler for zinc cooling tower and anti-fingerprint cooling tower. The 1500 embedded polycrystalline fiber module provides a long-campaign and stable solution for the DFF insulation. It can create a overhaul service by four times of brick-type refractory. The furnace is benefited for a less breakdown ratio and is protected from roller's surface cord. Under optimized safety strategy, the annealing furnace with embedded polycrystalline fiber modules, co-working with the after-burners in the fume duct outside the furnace, can precisely control furnace pressure, reduce furnace temperature and keep furnace's positive pressure. Hydrogen can be blown into the furnace within a safe period. Interlayer rollers are designed for zinc pot's cooling tower and anti-fingerprint coat cooler for post treatment, which will eliminate the zinc debris damage for the cooling roller surface. It's a desired substitute for air jet cooler for the anti-fingerprint post treatment. The mist cooling way enables an extremely-high heat transfer coefficient of 650 (kcal/m~2.h.°C) and results in a high cooling rate required for creating minimum zinc spangles. The cooling speed can be easily controlled while there is no strip oxidation.