Guidelines for Accurate Grit Sampling Evaluation of Current Sampling Techniques

A study was conducted to provide unbiased evaluation of two techniques commonly used for measuring grit quantity received and removed by grit removal equipment. The evaluation was performed using computational fluid dynamics (CFD) since field testing tends to be costly and time consuming. The two techniques are commonly known as cross channel sampler (CCS) technique and vertically integrated sampler (VIS) technique. The study quantifies sampling errors and presents mistakes that should be avoided to ensure collecting representative samples in the future. Four different cases were studied. In some cases, the sampling error exceeded 40 percent which is very alarming figure that warrants careful evaluation by the practitioners before replacing and/or designing new grit removal systems.