Experimental Study on Mixing Uniformity of Injection On-Line Mixer of Crop Protection Equipment

Abstract

In order to promote pesticide application reduction and efficiency enhancement, to avoid the direct mixing of pesticides caused by secondary pollution and life safety risksand, further improve the mixing uniformity of on-line mixing system of crop protection equipment. The numerical simulation on structural parameters and fluid parameters of the mixer was performed by the CFD method to determine the best structural parameters of the mixer. And an injection online mixing system experiment platform was built. The experiments were carried out by high speed photography and spectrophotometry respectively. The experimental results show as following: The variable mixing ratio experiment was carried out in the case of pure reagents mixing test in the mixer. When the water flow is 140 L/min and the pesticide pressure is 1 MPa, the ratio of pesticide solution is controlled in the range of 1:300 ~ 1:3000, and the images of pesticide entering the mixer are collected respectively. The results of image analysis and processing show that the online mixing system has good mixing performance in qualitative analysis. When the mixing ratio is 1:300 to 1:300 and the normal pressure of pesticide is 0.1 MPa, the maximum mixing uniformity variation coefficient of the pesticide solution is 6.87%. When the mixing ratio is 1:300, the minimum mixing uniformity coefficient is 3.33%. It is proved that the overall trend of mixing uniformity variation coefficient increases with the increase of mixing ratio when the pesticide is mixed at normal pressure. When mixing under pressure, the mixing uniformity coefficient of variation is less than 5% and the maximum is 3.903%, which indicates that the mixing uniformity of the mixer is well when mixing under pressure. The results can improve pesticide utilization, safety of plant protection, reduce secondary pollution and reduce pesticide residues. Through the qualitative analysis of high-speed photography, it is found that the drug mixer has good time and space distribution uniformity in the process of drug mixing. The quantitative detection of spectrophotometry shows that the drug liquid has good time and space distribution uniformity after passing through the mixer. The conclusion of this paper has certain guiding function and reference value for plant protection technology and liquid on-line mixing in chemical and pharmaceutical fields.