The paper analyses for design of the old type of BOP and presents some problems of it in field application by using CAD soft ware to design a modified BOP avoiding shortage of former one.

• 对旧式防喷盒的设计缺陷进行分析,并指出实际应用中存在的问题。应用CAD软件设计制作的改进型防喷盒克服了原设计的不足。