煤气化灰水系统结垢原因及处理技术分析

Cause and treatment technologies analysis of scaling in coal gasification ash water system

某60万t/a甲醇装置煤气化灰水具有高硬度、高碱度等特点,在系统运行期间易导致管道、设备结垢,造成堵塞。介绍了煤气化装置灰水处理单元的工艺流程,分析发现灰水处理单元结垢的主要原因为原煤中含有大量钙;采用药剂投加法并定期进行高压清洗或化学清洗,同时配合大量水的连续外排和新鲜水的补充,有效缓解了系统结垢速度。对比分析了传统煤气化工艺灰水处理采用的药剂投加法及行业内新兴的电化学法、电磁阻垢法、结晶造粒法等灰水降硬阻垢技术,建议各企业应结合自身运行情况,合理选择适宜的阻垢降硬技术。

The ash water of coal gasification plant had the characteristics of high hardness and high alkalinity,which was likely to cause scaling of pipes and equipment during the operation of the system,resulting in blockage.The process flow of the ash water treatment unit of coal gasification plant was introduced.It was found that the main reason for the scaling in the ash water treatment unit was that the raw coal contained a lot of calcium.The reagent dosing method was adopted and regular high-pressure cleaning or chemical cleaning was carried out.At the same time,with the continuous discharge of a large amount of water and the supplement of fresh water,the scaling speed was effectively alleviated.The comparison was made to analyze the traditional coal gasification ash water treatment using reagent dosing method and the new ash water scale inhibition technologies of the industry,such as electrochemical method,electromagnetic scale inhibition method,crystallization granulation method and so on.It was suggested that each company should rationally select appropriate scale inhibition and hardness reduction technologies based on its own operating conditions.