مطالعه تجربی و شبیه‌سازی لوله انتقال با مقطع واگرا در نقاله نیوماتیکی دانه‌های جو

Material handling systems are widely used in different sections of industry and agriculture. Pneumatic conveyors are methods of conveying granular and powdered materials that use airflow to transfer materials from one point to another. Particle conveying pattern and energy consumption of such conveyors are the parameters affecting the operation of this type of conveyor. In this study, to investigate the material conveying pattern and optimization of energy consumption, a divergent cross-section mechanism was designed and developed in the conveying pipeline. Its effect on barley grain conveying in a pneumatic conveying system was investigated experimentally numerically. Fluent software was used to solve the two-phase flow equations such as continuity and momentum, and for experimental evaluation, a factorial experiment in the form of a randomized complete block design with three replications was used. Duncan's test was conducted to compare the means of the treatments. The results of experiments and simulations of pipelines with divergent cross-sections indicate that the average inlet air velocity, the average pressure drop, and the average power consumption of the device in the dense phase in the auxiliary air mode were 8.6%, 6.67%, and 1.23% less than those obtained in no auxiliary air mode, and in the dilute phase in the auxiliary air mode were 3.56%, 4.66% and 5.21% less than the corresponding values in no auxiliary air mode, respectively. Also, the inlet of auxiliary air at a velocity higher than the inlet air of the environment increased the mass flow rate of the conveying particles by 17.3%. The particle velocity variation decreased in the divergent section, and the particle velocity became more uniform along the conveying path.