Combustion and explosion of flour is a popular research topic in the field of dust explosion. In this study, combustion and explosion processes of a two-phase flow of wheat flour in a pipeline are investigated using a horizontal dust combustion explosion experimental pipeline system with a length of 5.5 m and diameter of 100 mm. Physical properties of flour dust dispersed under different aerodynamic conditions are compared experimentally. The average characteristic diameter of the intrinsic characteristic of wheat flour D-50 was 36.80 mu m; the suspension characteristics of dust particles in the pipeline under pneumatic action are also obtained. When the density of the flour in the pipe is 800 g/m(3), the flame speed reaches a maximum of 289 m/s. When the quality of flour placed in the pipe continues to increase, after reaching 1000 g, the flame speed of the flour-air mixture explosion decreases. (C) 2019 Elsevier B.V. All rights reserved.