球墨铸铁管预热炉系统技术改造

Modification of Preheating Stove for Ductile Iron Pipes in Pipelines

随着铸管机的生产能力从14万吨增加到20万吨,外涂车间内配套的铸管预热炉不能满足生产能力与工艺要求,随着输送链的速度加快,铸管出炉温度只有30°左右,无法满足喷涂工序对温度的要求。在减少投资和运营成本的前提下,炉体整体结构与尺寸不变的情下,通过对预热炉的燃烧系统、热风循环系统、控制系统进行改造,把原有加热与循环系统分离的方式改为加热循环一体式,热风系统由原来的从头部到尾部的大循环方式改为上下对吹,中部回风的方式,增加循环量,提高风速及对流换热系数,实现了炉温从90℃升高到130℃,铸管出炉温度60°以上,同时保证了扩能后生产能力。经过3年多的生产实践,很好实现了预期的目标,为今后相类似的设备改造提供一定的借鉴意义。

When the production capacity of the casting machine increased from 140,000 tons to 200,000 tons,preheating furnace in coating workshop could not meet the production capacity and process requirements.As the conveyor speed increased, pipes temperature was only 30 ℃ after preheating,which could not meet the temperature requirements of the coating process.In the condition of minimum investment and operating costs, combustion system, hot air circulation system and control system were modified, while the overall structure and size of the furnace not changed.The separating heating and circulating system was changed to the integrated heating circulation system.The original circulation system from the head to the end, was modified to up and down blowing, central return system.After modification,the air circulation capacity was increased.air speed advanced,as well as convective heat transfer coefficient.The temperature in furnace was increased from 90 ℃ to 130 ℃ ,and pipes temperature was above 60~ ,and it matches the production capacity after expansion.After three years production practice,the desired objectives were achieved,which provided some references for modification of similar equipment in future.