河床深度服务时间（BDST）法是一种简单的方法，用于评估过滤器设计所需的系数，可以为深河床过滤器的设计提供合理的依据。一旦确定，这些系数以及水头损失估计值可用于评估流速、过滤器长度、进水浓度和出水悬浮固体浓度对过滤器运行长度的影响。这些系数可在中试工厂试验中使用不同长度的过滤器确定，或从单个现有过滤器的性能中确定，精度稍低。包括13个参考图表和表格。

The bed depth service time (BDST) method, a simple means for evaluating the coefficients needed in filter design, can provide a rational basis for the design of a deep bed filter. Once determined, these coefficients along with estimates of head loss, can be used to evaluate the effects of flow rate, filter length, and influent concentration and effluent suspended solids concentration on the length of a filter run. The coefficients can be determined in pilot plant tests using filters of various lengths or, with a somewhat lower accuracy, from the performance of a single existing filter. Includes 13 references graphs tables.