Computing Transmix in Complex Batch Transfers via the Mixing-Volume-Equivalent-Pipe Concept

This paper presents a new concept — the mixing-volume-equivalent-pipe concept (MVEPC) — which is used to compute transmix volumes in complex batch transfers in an easy, quickly and very simple way. By taking advantage of the MVEPC, the mixing volume of a transfer carried out in a complex pipeline, with varying diameters and flow rates, can be calculated as if it had a unique diameter and a constant flow rate. To illustrate the applicability of the proposed methodology, a numerical example is presented for a transfer of typical products. The transmix volumes predicted by the MVEPC are compared with those obtained by solving the nonlinear initial-value problem for the dispersion of matter parabolic equation. The excellent agreement observed between these two methods, with relative error up to a maximum of 2.65%, enables the use of the MVEPC as a promising tool for estimating transmix volumes in real world batch transfer operations.