The complexity of the gas-liquid two-phase flow results in equally complicated pressure drop characteristics for self-excited wet dust scrubbers. In this paper, the pressure drop of the dust scrubber was studied by measuring the total pressure drop R and the differential liquid level ΔH versus the gas velocity v at different initial liquid level b0 values, combined with the liquid flowability. The results showed that the dust scrubber varied its total drag coefficient by changing the differential liquid level ΔH of the liquid-phase and then adjusting the gas-liquid two-phase force balance ahead of and behind the choke. Under the influence of liquid flowability, the throttling strength α exhibited a linear relationship with the gas velocity of the dust scrubber when b0 ≤ 0 mm. The ΔH-v and R-v characteristics of the dust scrubber varied with different values of b0 and v. When b0 > 0, the ΔH-v curve and R-v curve exhibited an explicit quadratic curve relationship. When b0 ≤ 0 mm, the ΔH-v curve and R-v curve exhibited an explicit linear relationship, where the ΔH-v curves can be expressed by a linear equation ΔH = khv+ΔH0, and the gas-phase pressure drop R can be approximately calculated using the differential liquid level ΔH. The liquid flowability can change the choke-sectional to change the total drag coefficient, which reduced in multiple folds with an increase in the gas velocity.
