Numerical Simulation of an Online Cotton Lint Sampling Device Using Coupled CFD–DEM Analysis

Abstract

Cotton processing is the process of converting harvested seed cotton into lint by cleaning, ginning, and cleaning the lint. The real-time acquisition of lint parameters during processing is critical in improving cotton processing quality and efficiency. The existing online inspection system cannot realize quantitative sampling detection, resulting in large fluctuations in the detection of moisture rate, and the impurity content of lint can only be measured according to the number of impurity grains and the percentage of impurity areas. This research developed a quantitative sampling device for cotton lint processing that can collect the right number of cotton samples and obtain the weight of the samples, laying the foundation for the accurate detection of cotton lint dampness and impurity rates. This research aimed to develop an online quantitative sampling device with a sampling plate as its core. The quantitative sampling procedure, consisting of a gas–solid two-phase flow in a cotton pipeline, was numerically simulated and experimentally analyzed using computational fluid dynamics (CFD) and the discrete element method (DEM). According to the coupling results, the maximum pressure differential between the top and bottom regions of the sampling plate when conveying was 1024.45 Pa. This pressure is adequate to allow for cotton samples to accumulate on the sampling plate. Simultaneously, the steady conveying speed of lint is 59.31% of the unloaded conveying wind speed, providing a theoretical foundation for the sampling time of the quantitative sample device in the processing chain. The results from testing the prototype indicate that the quantitative sampling device in the cotton flow can effectively perform the quantitative sampling of cotton lint under uniform conditions, with a sampling pass rate of 84%.

Design and Optimization of a Mixed-Flow Drying Chamber for Tiger Nuts Based on CFD-DEM Heat and Mass Transfer Model

“…The standard k-ε turbulence model in ANSYS, the SST k-omega equation, is used as the turbulence model. The Ranz and Marshall heat transfer model and multicomponent model [15][16][17][18][19] are used because heat and mass transfer are considered in the work. In the component set, two compositions are identified: the evaporable component of water and a non-evaporable component of tiger nuts; the composition ratio is 45% and 55%, respectively.…”

“…In order to optimize the design of the drying system, the use of CFD-DEM modeling is the most effective way to achieve this goal [14][15][16][17][18][19][20]. Bin Lan et al [21] developed a CFD-DEM-IBM (immersed boundary method) method for the simulation of the particle drying process, which is useful for simulating the fluid flow, mass transfer, and heat transfer within a gas-fluidized bed.…”