氧化铝高压溶出套管预热器的设计分析

Design Analysis on Sleeve Preheater in High-Pressure Digestion of Alumina

'高压溶出'作为氧化铝拜耳法生产中重要工序之一,被称为氧化铝生产中的心脏工程.经过将近100年的发展,拜耳法溶出技术已逐步由最初的单罐间断溶出发展为现阶段国内普遍采用的管道化连续溶出.管道溶出设备管径小,比大直径溶出设备'压煮器'较容易实现高温、 高压.管道化溶出因具有导热性能好、 溶出时间短、 产能高、 溶出液苛性比值低等优点而被广泛采用.套管预热器作为管道化连续溶出技术中的核心设备,工作原理是利用双层管道,内管走矿浆,外管走热源,热量通过管壁传给矿浆,使矿浆得到溶出所需的高温.该文在分析了近10年来国内各大氧化铝厂套管预热器设计、 变更、 技改、 改进等情况的基础上,从多方面对该设备的设计进行分析,为后续同行业该设备的设计提供一定的参考.

As an important working procedure of alumina production process with Bayer method,high pressure digestion(HPD)is called the heart project of the alumina production.After nearly a hundred years of development,the dissolution technology in Bayer method has been developed from the initial intermittent process using some cans to the domestic general use of the tube digestion being a kind of continuous dissolution technology.The equipment used for the tube digestion has a smaller diameter than the autoclave,and is easier to reach high temperature and high pressure.It has higher heat conductivity,shorter working hours,higher productivity,lower caustic ratio and so on.So this technology is widely used.The sleeve preheater is the core equipment of the tube digestion.The way it works is that there are some double pipes,the ore pulp flows through the inner tubes,the heat source flows through the outer tubes,and the heat passes through the wall to the pulp,so that the ore pulp gets high temperature.In this paper,based on the analysis of the sleeve preheater of domestic oxidation aluminum plants in the past ten years,the design of this device is analyzed from many aspects for the design of this kind equipment in the same industry.