何威威毕业设计.doc

北华大学毕业设计(论文) - 1- 摘要现今的自动化水平逐年增高, PLC 作为主控制器,一直处在整个技术领域的主要战场。为许许多多的自动化装备提供了很好的控制环境。作为一个控制器, PLC 可以给自动化装备提供牢靠且安全的运行方案, 完全适应当今大部分工厂对自动化的需求。本论文主要研究的是一个以 PLC 为自动控制的核心, 设计出一个电解铝生产过程中氧化铝粉输送的自动控制系统。由于传统采用机械式输送,运输过程中氧化铝粉飞扬损失大、污染严重,而且加料量不容易控制,能耗大。所以本课题中采取浓相气力输送技术, 浓相输送氧化铝粉末技术具有长距离输送、粉末状物料在整个输送过程中飞扬损失小、运行安全牢靠且高度自动化等优点。浓相输送技术是由压力罐系统、浓相管和 PLC 自动控制设备等组成。它的工作原理是:物料进入压力罐中后经压缩空气加压呈沸腾状态,并维持这一状态,确保物料进入特制的浓相管中就被压缩空气分割成一段一段的料栓向前流动,实现物料的输送。整个控制系统采用 PLC 控制器, PLC 具有可靠性高,抗干扰能力强,编程简单易学,适应性好,功能强大等优点, 可以很好地解决氧化铝输送过程控制中的安全、灵活、环保、经济等问题。关键词: PLC ; 氧化铝粉浓相输送; 监控北华大学毕业设计(论文) - 2- Abstract Today's automation technology is developing rapidly , remain the key battleground in the field of industrial automation control of PLC , for all kinds of automatic control equipment provides a reliable control applications. The main reason is that it can provide safe and reliable for the automated control application and more perfect solutions , suitable for the current industrial enterprise of automation need. This topic research isa programmable controller (PLC) as the core of the automatic control equipment , design a electrolytic aluminum production process of alumina powder conveying system of automatic control. Because of using traditional mechanical conveying alumina powder dust during the process of transportation damage , pollution is serious , also add capacity is not easy to control , large energy consumption. So this topic in the dense phase pneumatic conveying technology , dense phase conveying alumina powder technology characteristics of long transmission distance , low energy consumption , low material in the process of conveying broken refining , flying material loss is small , stable and reliable and highly automated operation , etc. Dense phase conveying technology consists of pressure tank system , dense phase and consists ofa PLC automatic control equipment , etc. Its working principle is: after the material into the pressure tank in boiling state by pressed air pressure , and maintain this sta