120t转炉冶炼D07钢控氧工艺的研究与实践

根据D07钢的特点和实际生产情况介绍了此钢种转炉生产工艺,从理论到实践对D07钢种冶炼的五个工序的控氧方面进行了分析,最后得出合理的工艺参数。经过多次生产试制,D07钢种的质量能够满足用户的要求。

φ75mm直拉硅单晶的控氧工艺

一、前言 一般地说,氧是半导体材料硅中含量最多的杂质,其含量可达10^(18)cm^(-3)数量级。硅中的氧兼有优缺点。优点为“吸除效应”和“钉扎效应”;缺点是单晶的电阻率和寿命会受影响,易出现诱生缺陷,晶片可能变形。优点对器件工艺有利,缺点对器件工艺有害,使晶片质量变坏。 众所周知,不同器件要求不同的氧含量:p型(100),[O]=1.0～1.3×10^(18)cm^(-3),用于MOS;n型(100),[O]=1.

可控氧含量工艺在硫黄回收装置停车过程中的应用

硫黄回收装置传统的停工吹硫工艺是在清洁酸性气模式下将Claus制硫部分催化剂热浸泡48h后,再将尾气加氢还原吸收部分切除单独进行加氢催化剂钝化操作的一种工艺流程。根据GB 31570-2015《石油炼制工业污染物排放标准》中SO2排放量≤100mg/m3的要求,硫黄回收装置采用传统的停工方法难以使尾气中SO2达标排放。提出采用可控氧含量法,将低流量酸性气热浸泡后由清洁酸性气吹硫模式替换成燃料气吹硫模式,燃料气与配风既当量燃烧又同步提升增加了过程气流量,并与尾气处理部分和CTS络合铁脱硫单元同时运行。严格按要求分阶段控制过程气氧含量严防加氢反应器床层飞温,控制CTS单元循环溶液pH值稳定在8~9。延长停工吹硫时间,可以在降低排放超标风险的同时降低催化剂床层残余固态硫含量。经过数次停工实践,该方法能满足GB 31570-2015的要求,具有很好的经济效益和环保效益,为同类装置停工过程降低SO2排放提供了参考。

Design of an Expert Control System for Biogas Fermentation Process

Controlling the biogas fermentation process is the key for maintaining stable operation of biogas system and increasing gas yield. Aiming at features of biogas fermentation process and difficulties of control, a practical control scheme is proposed combining the abundant experience of biogas experts. And it discussed the structural design and hardware configuration of the expert control system, established the database and role base, and designed the control strategy of production system inference. The design scheme with ZigBee and PDA technology as core is employed so as to solve problems of environmental factor detection and data transfer management. The test result shows that the deviation of temperature is controlled within ± 0.9℃, the deviation of pH is controlled within ±0.3, the deviation of oxidation-reduction potential is controlled within ±30mV, the deviation of gas production is controlled within ± 9mL and that of methane concentration is controlled within ±4.5%. This system is easily expandable and applicable to biogas engineering at various scales.