extended furnace meaning in English

前置炉膛
前置燃烧室

The results of experiments taken in handan iron & steel co . ltd show that adoption of lining protection by slag splashing can drastically extend furnace campaign , reduce consumption of refractory material and improve availability of converter , thus achieving remarkable economical benefits . it is worthy of being extensively applied
邯钢的溅渣护炉试验结果表明，采用该工艺能大幅度提高炉龄，降低耐火材料消耗，提高转炉作业率，综合经济效益可观，值得推广应用。