有机肥生产中的多段式搅龙设计与性能试验

为解决有机肥生产过程中的堵料、物料混合不均匀和尾端积料等问题,设计了一种多段式搅龙,其主要由伸缩扒齿、进料段、变径送料段、大径送料段、出料段和反旋向段等组成。该文确定了伸缩扒齿偏心、搅龙变径和尾端反旋向等主要结构参数,明确了物料混合均匀性、抗堵料和防积料性机理,利用EDEM软件对多段式搅龙和传统搅龙进行性能对比试验和分析,并进行了样机试验。试验结果分析表明:当物料的混合均匀度标准差达到0.2时,多段式搅龙需要输送的距离是传统搅龙的0.6倍,传统搅龙的标准差最小值较多段式搅龙内的标准差最小值增大0.042;在进口处的填充度相等的情况下,物料输送过程中多段式搅龙内的填充度会逐渐下降(趋于0.222),多段式搅龙内的填充度变化幅度为38.1%,而传统搅龙内的填充度保持不变;多段式搅龙装备比传统搅龙装备输运效率提高了20%。研究结果可为有机肥生产装备的设计提供参考。

Design and performance experiment of multi-segment type auger in process of organic fertilizer production

Abstract: Organic fertilizer is processed by animal and plant residues or waste to eliminate the toxic and harmful substances. Organic fertilizer can improve soil and fertility, and can provide comprehensive nutrition for crops. In recent years, organic waste is decomposed into organic fertilizer in a short time by using rapid fermentation technology, adopting new techniques and equipments, and the fermentation is quick and free of pollution. This technology requires homogeneous fermentation conditions in the fermentation bin. Many scholars apply the auger to the organic fertilizer fermentation equipment to stir and transfer to improve the degree of automation. In the process of organic fertilizer production, it is easy to cause the problems of blocking material, uneven mixing of materials and end accumulation by traditional auger, which affects the full fermentation, resulting in low fertilizer efficiency and poor quality. In order to solve the problems, a multi-segment type auger is designed. The device is composed of telescopic gear, feeding section, variable diameter feeding section, large diameter feeding section, discharging section and reverse rotating section. The mechanism of the material mixing uniformity is clarified by eccentric design and analyzing the movement of the telescopic gear. The anti blocking mechanism of the device is defined through the design of variable diameter structure and analysis of material filling degree. The problem of deposition is solved through the design and analysis of the counter rotating section. The simulation performances of the designed multi-segment type auger and the traditional structure auger are compared with the discrete element analysis software EDEM. By comparing and analyzing the simulation results of the standard deviation between materials degree of mixing and optimal materials degree of mixing which in different positions, it is derived that when the standard deviation of mixing uniformity of the material reached 0.2, the distance required by the multi-segment type auger is 0.6 times as much as that of the traditional auger. Besides, the results also show that there existed a "dead zone" in the traditional structure auger in which the particles are difficult to contact with other particles. It is caused that the extremum of standard deviation of the materials in the traditional structure auger is about 0.042 larger than that of the materials in multi-segment type auger. By comparing the quantitative analysis of degree of filling of 4 sampling position in fermentation bin, it is derived that the degree of filling at the inlet is approximately equal, but the orientation about the degree of filling will gradually decrease and finally reach a constant value of about 0.222 in the process of materials conveying of multi-segment type auger, the change degree of filling degree in multi section auger is 38.1%, traditional structure auger fundamentally maintain a smooth trend. The transport efficiency of the multi-segment type auger is 20% higher than that of the traditional auger. It is verified that anti-clogging ability of multi-segment type auger is so strong that it is more suitable for the production of organic fertilizer requirements. The prototype test is basically consistent with the results of discrete element analysis, and the design meets the requirements of organic fertilizer production. This study can provide reference for the design of organic fertilizer production equipment.