一种钛白粉转窑煅烧尾气余热利用新装置

A new device for utilizing waste heat from calcination tail gas of titanium dioxide rotary kiln

钛白粉煅烧转窑尾气的高湿、高硫、高酸露点的特性使得转窑尾气余热利用过程中换热器寿命不理想。在总结已有尾气余热利用方式存在问题的基础上,提出了一种长寿命、易维护的套管式热管余热利用装置,该装置由彼此分离的换热套管通过弯头、法兰连接成为整体,尾气垂直横掠双层套管段,与高硫、高湿的尾气通过相变介质的相变完成热量由尾气向取热介质的转移,产生钛白粉生产工艺所急需的蒸汽,双层管的相变换热套管对比单层管的重力热管换热器寿命明显延长;连接换热套管的单层管弯头不与高湿、高硫尾气换热,大大减轻了尾气对单层管的腐蚀。换热器应用在3.6 m×58 m的钛白粉煅烧窑上,每年可以产生0.9 MPa的水蒸气1.12万t,为企业带来可观的经济效益。

The characteristics of high humidity,high sulfur and high acid dew point of calcination tail gas of rotary kiln of titanium dioxide shortens the life of metal heat exchanger.On the basis of summarizing the existing problems of the previous waste heat utilization methods of the rotary kiln tail gas,a long-life and easy-to-maintain bushing heat pipe waste heat utilization device was presented.The device is made up of separate heat pipe bushings connected by inner pipe elbows and flanges.The calcination tail gas crosses the double-layer heat pipe bushings vertically,and heat is transferred from the calcination tail gas to the heating medium through the phase change of the phase change medium.Then the steam required by the production of TiO2 was obtained.Compared with single-layer gravity heat pipe heat exchanger,the bushing heat pipe exchanger life span of the double-layer tube is obviously prolonged;the elbow of the single-layer tube connecting the heat pipe bushings does not contact with calcination tail gas,which greatly reduces the corrosion to the single-layer pipe.The bushing heat pipe heat exchanger is used in the 3.6 m×58 m titanium dioxide calcining kiln,it can produce 11.2 kt annually water vapor with 0.9 MPa pressure,brings enormous economic benefits to enterprises.