Study on Fiber Clogging Mechanism in Sewage Pump Based on CFD–DEM Simulation

Abstract

A large number of solid particles and fibrous impurities are always entrained in the fluid transported by a sewage pump, which can easily lead to the blockage of the sewage pump. In view of this, CFD–DEM simulations were conducted in this paper to reveal the fiber clogging mechanism in the sewage pump. A CFD–DEM coupling method with a fiber model was established and verified by an experimental benchmark, i.e., the rectangular flow channel. The method was then applied to a model sewage pump to, after mesh independence tests, analyze the effects of flow rate and fiber length on fiber motion and clogging. The results showed that the position of fiber retention coincides with the position of the vortex, mainly located at the inlet of the impeller, the head of the blade, the middle of the blade, and the tongue in the pump. In the case of a low flow rate, the fiber was more likely to cause blockage in the head of the blade, and in the case of a large flow rate, the fiber would wind around the tongue in the pump. At the same flow rate, long fiber was more likely to stay on the blade’s suction surface.

Study on the Unsteady Characteristics and Radial Force of a Single-Channel Centrifugal Pump

“…The impeller is a space-distorted flow channel from inlet to outlet; therefore, it has good nonclogging and anti-entanglement properties and is widely used in the transportation of sediment-containing water flow or the transportation of large particle solids. 2 The mass distribution of the impeller is asymmetric, and the volute is mounted nonaxially on the outside of the impeller, which makes the static pressure distribution around the impeller very uneven and produces unstable radial force under the interference of the volute and the impeller, making the pump less stable, and the noise caused by vibration is greater. Especially today's centrifugal pumps have been developed for large and high power, the hydraulic-induced excitation force of centrifugal pumps has also increased geometrically, and the strong unstable flow and pressure fluctuation caused by RSI (rotor−stator interaction) in the pump produce periodic hydrodynamic action on the impeller surface, resulting in strong rotor vibration.…”

“…It is a special centrifugal pump. The impeller is a space-distorted flow channel from inlet to outlet; therefore, it has good nonclogging and anti-entanglement properties and is widely used in the transportation of sediment-containing water flow or the transportation of large particle solids …”

Exploring characteristics of time-resolved signals in the operation of wastewater pumps

“…They specifically evaluate the probability of passing of the inserted materials to judge a pumps susceptibility to clogging. Zheng et al (2022) present a simulation model to analyze the interaction of fibers with wastewater impellers, but only present a brief experimental section focused on the verification of flow characteristics of the impeller, and not actual interactions. As Jensen et al (2015) report in their meta study, many similar studies exist that only present numerical models and simulations of specific impellers, but no experimental verification.…”