An investigation of effective parameters on pressure drop in vertical dilute phase pneumatic conveying for corn seed

Loading and unloading of produced crop is one of the phases in traditional and semi mechanized agriculture in transporting it from farm to silo for selling it. Unfortunately, major part of transport and movement is done by man power, which in addition to high cost, excessive exhaustion of the workers viewed as its consequences. Pneumatic system is the best way of transportation with considered conditions. This system with low mass can transport granular materials without producing dust.The overall purpose of this research is design and manufacture of dilute-phase pneumatic conveying system for transporting corn seed and study of the effects of vertical pipe length (1, 2 and 3 m), speed of air supply (13, 17 and 20 m/s) and mass flow rate (200, 250 and 300 kg/hr) changes on pressure drop after transport. Machine's potency was acquired through empirical relationship. Transition pressure drop including air frictional pressure drop (ΔPL), corn accelerated pressure drop(ΔPA), corn frictional pressure drop(ΔPz*), corn suspension pressure drop (ΔPG) and total pressure drop of elbows (ΔPbend) are required to determine the required blower power. The total pressure drop carried out with summing up the individual contribution of air and solid by using theoretical equations which obtained 1265.60 Pa and required blower power was achieved 133.68 W. The experimental design was factorial based on completely randomized design with three replications. Analysis of variance (ANOVA) and mean comparisons and interaction between the parameters were performed using the SAS software. The results of the experiments showed that, by tripling the length of the vertical pipe, the pressure drop increased significantly (P≤0.01). Also, with increasing air velocity and mass flow rate, the pressure drop increased significantly (P≤0.01). It was also found that the increase of the pressure drop was directly related to the length of the pipe, and the length factor versus the speed factor was more effective in reducing the air pressure.