摘 要

本课题是11万吨/年钛白尾气余热回收系统。众所周知，钛白粉是目前已知的最适合的白色无机化工颜料。但钛白粉在生产工艺过程中工况条件恶劣, 腐蚀严重 ,因此在设计及防腐蚀施工中,必须充分掌握材料及工程方面的知识 ,且要有经济观点 ,能够提出经济、合理、实用、高效的防护措施 ,同时严格执行施工的质量管理,本课题旨在提高钛白尾气的余热回收效率

由于排放的废气中含有水蒸气、硫化物等，当排气温度低于露点温度时，将会发生低温腐蚀。所以本课题通过回收钛白尾气余热，来加热饱和水使之蒸发生成高品位的饱和蒸汽。相比于采用直接余热回收蒸发器，本课题采用的以导热油为热媒的间接取热方式更容易控制和尾气接触部分的传热面壁温，避免了传热面的露点腐蚀。同时本课题采用普通ND钢作为取热段的传热面材质，大大节约了余热回收设备的制造成本。导热油作为液态热媒可以在低压状态运行，使系统运行平稳。取热段设置成尾气竖烟道布置，使得传热面管水平放置，有利于尾气中TiO₂粉尘的下落回收。

本课题烟道竖直布置，方便积灰下落。以导热油作为热媒，设置合理的导热油进出口温度，回收热量的同时可以避免露点腐蚀的发生。同时布置一定数量的加强以装置保证换热管的强度。在导热油蒸发器中，水量占总体积的1/3，蒸汽量占总体积的2/3，并且导热油蒸发器内的水的量保证了在不供水的前提下，维持蒸发15分钟左右。

关键词：钛白尾气 余热回收 热媒 低温腐蚀 节能

ABSTRACT

The subject is 110,000 tons / year titanium dioxide exhaust heat recovery system. As we all know, titanium dioxide is currently known as the most suitable white inorganic chemical pigments. However, in the process of design and anti-corrosion construction, it is necessary to fully grasp the knowledge of materials and engineering, and to have economic point of view, to be economical, reasonable, practical and efficient. Of the protection measures, while strict implementation of the construction of quality management, the subject aims to improve the waste heat recovery efficiency of titanium dioxide

As the exhaust emissions of water vapor, sulfide, etc., when the exhaust temperature is lower than the dew point temperature, will occur low temperature corrosion. Therefore, the subject by recycling titanium waste heat, to heat the saturated water to produce high-grade saturated steam. Compared with the use of direct waste heat recovery evaporator, the subject used to heat the oil as the heat medium indirect heat way easier to control and the contact part of the heat transfer surface wall temperature, to avoid the heat transfer surface dew point corrosion. At the same time, this paper adopts ordinary ND steel as the heat transfer surface material of heating section, which greatly saves the manufacturing cost of waste heat recovery equipment. The heat transfer oil as a liquid heat medium can run at low pressure and make the system run smoothly. Take the heat section is set to exhaust vertical flue arrangement, making the heat transfer tube level placed horizontally, is conducive to the tail of the dust in the dust recovery.

The subject flue is arranged vertically to facilitate the fouling. To heat the oil as a heat medium, set a reasonable heat transfer oil inlet and outlet temperature, heat recovery at the same time to avoid the occurrence of dew point corrosion. At the same time, a certain amount of reinforcement is arranged to ensure the strength of the heat transfer tubes. In the heat transfer oil evaporator, the amount of water accounted for 1/3 of the total volume, the amount of steam accounted for 2/3 of the total volume, and the amount of water in the heat transfer oil evaporator to ensure that no water supply under the premise of maintaining evaporation for about 15 minutes The

Key words: titanium white exhaust gas waste heat recovery heat medium low temperature corrosion energy saving

目录

摘 要 I

ABSTRACT II

第一章 绪论 1

1.1 研究背景 1

1.2 钛白粉的应用 1

1.3 钛白粉常用的加工方法 2

1.3.1 钛矿加工工艺 2

1.3.2 硫酸法生产工艺 2

1.3.3 钛白粉新生产工艺 2

1.4 钛白粉材料工业现状 2

1.5 新技术 3

1.6 关于腐蚀 4

1.6.1 水喷淋法 碱喷淋法 4

1.6.2 大烟筒喷淋法 4

1.6.3 水喷射吸收法 4

1.7 关于热媒炉 5

1.7.1 加热性能好 5

1.7.2 安全性能高 5

1.7.3 易于实现自动化控制 5

1.7.4 维护管理方便 5

1.8 本章小结 5

第二章 11万吨/年钛白尾气余热回收系统设计 6

2.1 设计要求 6

2.2 钛白尾气余热回收系统设计中要考虑的问题 6

2.3 热力计算中遇到的问题 6

2.4 图纸设计所遇到的问题 7

第三章 热力计算书及结构设计 8

3.1 原始设计参数 8

3.2 取热器设计 8

3.2.1 热平衡计算 8

3.2.2 结构设计 10

3.3 导热油蒸发器设计 17

3.3.1 热平衡计算 17

3.3.2 结构计算 18

3.4 导热油蒸发器尺寸设计 20

3.5 施工图设计 21

第四章 总结 22

参考文献 23

致谢 26

第一章 绪论

研究背景

钛白粉是目前已知的最适合的白色无机化工颜料。由于世界的贫富差距过大，杜邦、石原等八家公司占据了绝大多数的钛白粉市场。2002年全球钛白粉生产能力约460万吨,市场价值约100亿美元^[1-3]。

钛白粉的应用

钛白粉主要有大粒氧化钛、纳米氧化钛等。它是目前全球应用较为广泛的无机精细化工产品之一。它在这些化工产品中有着很大的比重，最大的用途是作为一些拥有特殊性质的的白色无机填料来满足其他行业对产品的一些特殊需求。

（1）大粒径的TiO₂的应用