螺旋折流板换热器折流板的数控加工

螺旋折流板管壳式换热器比传统的弓形折流板换热器具有更高的换热效率,但是螺旋折流板结构实现起来十分困难,阻碍了其在工程上的应用。螺旋折流板在壳程内倾斜布置,与换热管交叉成一定角度,上面的孔为斜孔,采用传统的机械加工方法难以实现。针对2管程换热器,将一个周期的折流板分为4块,对折流板上管孔的排布方式进行研究分析,找出规律,建立了数学模型,用EIA代码编制了数控加工程序。在MITSUBISHI操作系统的数控钻铣床上,采用特殊的刀具,将折流板点焊为一摞,装夹在旋转工作台上,使之与刀具成一个固定角度,实现了阶梯式螺旋折流板上孔的加工,解决了制造的难题,提高了生产效率和钻孔精度,为螺旋折流板管壳式换热器的推广应用提供了可能。

Numerical controlled process of baffles on helix-baffled tubular heat exchangers

The helix-baffled tubular exchanger is more efficiency in heat transfer than general exchangers,but the helix baffled-structure is too difficult to be fabricated,which is the main reason why it can't be used in plant.The baffles installed in the shell are not perpendicular to the tube,that is,the axis of the hole on the plate is not perpendicular to the baffle's surface,but forms into a definite angle.The baffles are very difficult to be manufactured using common machine tools.Aimed at heat exchanger with two courses in tube side,one baffle was split into four parts.The tube holes' distribution on baffles was analyzed,and the mathematical model was developed.Numerical controlled program was compiled with EIA code.The baffles were welded into a pile,then the holes were drilled using milling cutter and twist drill.The baffles were installed on Mitsubishi numerical controlled machine,and numerical controlled process was realized.This can improve production efficiency,which makes it possible that helix-baffled tubular heat exchangers can be widely applied in factory.