A One-D approach for modeling transport and deposition of Black Powder particles in gas network

Abstract

Black Powder (BP) is a universal issue in sales gas transmission pipelines. It can cause serious problems in pipelines operations and instruments and contaminate customer supply. The objective of the present study is to develop a novel methodology for tracking the dispersion of Black Powder within gas transmission pipelines using a 1D approach based on the dusty gas assumption and the usage of analytical solutions of one-dimensional scalar advection/reaction equation. The study takes into account the deposition of Black Powder particles under different flow conditions, different particle diameters and different surface roughness. The proposed approach is applied to particle-laden flow in pipe segments with and without junctions and contrasted against CFD simulations based on the Discrete Phase Model (DPM). The results show that the finer particles with diameters dp < 1 (μm) can be transported easily to the downstream of the tree shaped network, while the larger particles dp > 1 (μm) are likely to settle rapidly near to the source location where Black Powder is generated and, consequently, forming beds. It is shown also that surface roughness increases the deposition rate of small particles dp ≤ 1 (μm) controlled by the Brownian forces. However, the deposition of larger particles in the inertial regime is not affected by the change in the surface roughness. These reported results are of significant practical interest, due to the lack of available data of Black Powder concentration in natural gas networks that have been reported in the literature to date.