大型串联电子束熔炼炉抽真空系统设计研究

Design and Research on Vacuum System of Large Series Electron Beam Melting Furnace

针对目前大型串联电子束熔炼炉抽气系统设计选型困难的问题,提出了一套电子束熔炼炉抽气系统设计方法。首先按照真空炉体的气体载荷计算有效抽速,粗选主泵,并用有效抽速和抽真空系统的流导验算主泵的抽速;其次对主泵的前级以及真空炉体的预抽泵进行选型,计算前级泵与预抽泵的抽速;再次计算粗抽时间与抽高真空时间以验证选型的合理性;最后通过试验对设计的电子束熔炼炉系统进行验证。结果表明,所设计的炉体抽真空系统粗抽时间与高真空抽气时间略高于计算时间,极限真空度优于设计要求。该方法计算结果与试验结果具有较高的一致性,可满足类似大型真空熔炼炉的抽真空系统设计需求。

A design method for the vacuum system of a large series electron beam melting furnace is proposed to address the difficulty in selecting and designing the exhaust system.Firstly,calculate the effective pumping speed based on the gas load of the vacuum furnace body,roughly select the main pump,and then verify the pumping speed of the main pump using the effective pumping speed and the flow conductivity of the pumping system.Secondly,select the front stage of the main pump and the pre-extraction of the vacuum furnace body,and calculate their pumping speed.Then calculate the rough extraction time and high vacuum extraction time to verify the rationality of the selection.Finally,verify the designed electron beam melting furnace system through experiments.The results show that the designed furnace vacuum system has a slightly higher crude and high vacuum extraction time than the calculation time,and the ultimate vacuum degree is better than the design requirements.The calculated results of this method are highly consistent with the experimental results and can meet the design requirements of vacuum systems similar to the large vacuum melting furnace.