采用数值模拟方法分析了不同工艺因素对RH精炼中夹杂物去除过程的影响。数值结果表明:小尺寸夹杂物的碰撞长大可有效降低其数量密度,大尺寸夹杂物主要通过上浮去除;浸渍管插入深度、真空室压力和吹氩量是影响夹杂物去除的3个重要参数,其中吹氩量最为显著;在避免发生卷渣的前提下,减小浸渍管插入深度有利于夹杂物去除;在合金化脱氧后,保持较高的真空度可促进夹杂物的去除;在浸渍管插入深度为500 mm,真空度为1kPa的条件下,吹氩量达到2000 L时夹杂物去除率可达到75%;吹氩量达到饱和值后,进一步增大吹氩量不能继续促进10μm以上夹杂物的去除。
The numerical method was employed to study the effect of technological factors on the inclusion removal in RH degasser. The numerical results indicated that for small inclusion, the number density can be decreased effectively by collision growth. For big inclusion, the number density can be decreased by Stokes floatation. The inserting depth of the snorkels, the vacuum chamber pressure and the gas flow rate are three key parameters of inclusion removal and the gas flow rate is the most important one. There are two measures to promote the inclusion removal rate. One is to decrease the inserting depth of the snorkels if slag entrapment does not occur; the other is to keep high vacuum degree after deoxidization by aluminum feeding. On the condition of 500 mm of the inserting depth of the snorkels and 1.0 kPa of vacuum chamber pressure, the inclusion removal rate can reach 75 percent while the gas flow rate is up to 2 000 L. The removal rate for inclusions whose size is greater than 10 micron can not be promoted further after the gas flow rate reaches its saturated value.