Optimization of the impeller of sand-ejecting fire extinguisher based on CFD-DEM simulations and Kriging model

To explore the optimal impeller of fire extinguishing equipment within a larger range, the Latin hypercube sampling and Kriging method was adopted to establish the response surface with two input factors (the blade number and the angle of inclination). The study found that a longer scattering distance can obtain a better fire-extinguishing effect, and the air volume flow rate at the scattering outlet has no obvious relationship with the scattering effect. The predicted optimal result is the impeller with 10 blades and 15.13° forward. However, compared with previous research results, this only brings a slight scattering distance improvement. Therefore, increasing the number of blades did not lead to a significant increase in scattering distance. This study will provide effective references for further optimization research of the sand-ejecting fire extinguisher and guide its optimization direction to other parameters of the impeller.