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在球罐制造中,为了防止延迟裂纹的产生,焊接作业时,必须在焊前预热、焊后进行后热消氢处理。预热、后热的温度及其与时间的关系曲线,曾在《石油施工技术》杂志中刊登,在此不再赘述。而预热、后热的热源,就目前来说有两种:气体加热和电加热。气体加热一般采用液化石油气为燃料,较先进的火焰燃烧器被称为二次燃烧系列管喷燃器,它的热效率较高。火焰燃烧器排列在焊道两侧,可根据被加热容器的壁厚不同以及加热温度的高低,适当选择烧嘴孔径大小以及排列疏密,并对气流量进行调节或分路进行开—闭程序用阀门控制。目前国内使用的气体加热器,
In the manufacturing of the spherical tank, in order to prevent the occurrence of delayed cracks, the welding operation must be preheated before welding and after the welding, the hot hydrogen elimination process is performed. Preheat, post-heating temperature and the relationship between the time curve, was published in the “Oil Construction Technology” magazine, not repeat them here. The preheating, hot after the heat, for the moment there are two: gas heating and electric heating. Gas heating is generally used liquefied petroleum gas as fuel, more advanced flame burner is called secondary combustion series tube burner, its thermal efficiency is higher. Flame burners arranged on both sides of the weld bead can be heated containers according to the different wall thickness and the heating temperature level, the appropriate choice of burner aperture size and arrangement of density, and the gas flow to adjust or branch to open - closed procedures With the valve control. At present, the use of gas heaters,