Accuracy Analysis of Slurry Characterization in a Rectifying Liquid Concentration Detection System

Accurately detecting coal slime water concentration during coal washing is crucial for optimizing dosing systems and improving separation efficiency. Traditional concentration detection methods are often affected by flow field disturbances. To address these limitations, this paper proposes a pressure differential concentration detection system utilizing interference rectification for a stabilized flow field and improved measurement accuracy. The experimental system comprises a circulating slurry tank, a defoamer, and a turbulence removal measuring tank. Numerical simulations and experimental studies investigated the effects of slurry concentration and inflow velocity on detection accuracy. Through dynamic measurement of pressure difference data under different concentrations and flow rates, the characteristics of a solid–liquid two-phase flow field are simulated using Fluent software. The results demonstrate that for low-concentration (C = 10%) and high-concentration (C = 30%) slurries, a flow velocity of ≥0.7 m/s significantly improves flow uniformity and achieves a stable particle suspension state, maintaining a measurement error within 1% for a flow rate of 0.7 m/s. However, flow rates exceeding 0.7 m/s decrease flow stability, increasing errors. Notably, the combination of sensors at positions No. 2 and No. 4 yields the lowest measurement errors, which verifies the influence of sensor layout on detection accuracy. A 0.7 m/s velocity is identified as the key threshold for flow field stability, and the nonlinear influence of the synergistic effect of flow rate and concentration on the detection stability is revealed. These findings provide valuable insights for optimizing pulp concentration detection systems and enhancing industrial dosing precision.