In order to determine the influence on account of operating conditions, aeration time, DO, reflux ratio, water drainageratio were studied by using small CAST test-bed.
为了确定运行条件的影响，采用搭建CAST小试试验台对曝气时间、DO、回流比、排水比进行了研究。
2
By controlling the range of the dry density, magnitude of cement and water cement ratio of mixture, the requirement of drainage property and structure strength can be fulfilled.
通过控制混合料的干密度、水泥用量和水灰比的取值范围，可使混合料同时满足排水性能要求和结构强度要求。
3
Finally, with the air of freedom multiplied by the number of air compression ratio that the pressure can be drainage, to determine choose which kind of air compressor.