目的 降低炉内氧化烧损，提高产品的成材率。方法 板坯在上料辊道上及进加热炉前，当检测的板坯温度低于300 ℃时，利用辊刷及空气吹扫装置清理上下表面后，喷涂一层防高温氧化隔离剂，然后装炉加热，经热连轧成卷。为了减少隔离剂的浪费，提高喷涂效果与设备运行效率，将毛状细钢丝改为钢丝绳，截止阀到喷嘴的距离（需要清洗段）由原约4 m缩短为0.2 m，材质由软塑料管改为内径5 mm的铜管。因上料辊道长度短，超过300 ℃的热坯必须停留在喷涂罩内，且时间不固定，因此系统设置停留时间≤10 min则继续喷涂，否则，清洗管路，停止喷涂。为了解决停留后需继续喷涂，导致喷涂层厚度不均，最终造成中间坯同块钢出现温度陡降的问题，需要延迟溢流阀门关闭0.5 s，喷涂系统压力维持在0.3 MPa之内。结果 成材率可以提高0.3%以上，吨钢涂料消耗控制在0.33 kg以内。结论 通过优化喷涂设备结构、材质以及喷涂溢流阀门动作时序，控制系统压力，能实现自动喷涂，获得涂层均匀、节省涂料、提高成材率的效果。

Objective To reduce oxidation burning loss in furnace and increase product yield. Methods When a slab on the charging table (before it was fed onto loading roller bed and pushed into furnace) was less than 300 ℃, its top and bottom surfaces were cleaned up with roll type brush and air blow off set. Then oxide isolator resistant to high temperature was sprayed to its surface. It was then charged into furnace, and finally rolled into a hot strip coil. To reduce consumption of oxide isolator and improve the effect of spraying and the efficiency of operation, thin steel wire was changed to steel wire rope. The distance from stop valve to spraying nozzle (the section to be cleaned) was shortened from about 4 m to 0.2 m. Material used was changed from plastic soft pipes to brass hard ones with 5 mm inner diameter. As the loading roller bed was short, hot slabs over 300 ℃ must stay in the spraying cover. Besides, staying time was random. Therefore, if the set staying time was ≤10 min, spraying would continue; otherwise, spraying should be stopped and pipelines should be cleaned. But there were some troubles which caused non-uniform temperature of intermediate slab because of non-uniform thickness of painting when spraying system was restarted. Overflow valve was delayed to be closed for 0.5 s and pipe pressure was kept within 0.3 MPa. Results The product yield increased by over 0.3% and the consumption of steel coating per ton was controlled within 0.33 kg. Conclusion Optimization of spraying equipment structure, material and closing scheduling of overflow valve and control on system pressure will realize automatic spraying, produce painting with uniform thickness, save coatings and increase product yield.