对辊式红花采收装置参数优化及试验

为了提高对辊式红花采收装置的作业质量,以"裕民无刺"红花品种为试验对象,利用搭建的对辊式红花采收试验台,以对辊间隙、胶辊直径和胶辊转速为影响因素,采净率、掉落率和破碎率为评价指标,进行了二次旋转正交组合试验。通过Design-Expert 6.0.10软件,建立了评价指标与诸影响因素的数学回归模型,分析了显著因素对评价指标的影响,优化试验参数,确定最优参数组合为:胶辊直径40 mm、对辊间隙0.5 mm和胶辊转速1 400 r/min。根据优化参数组合,选取开花后1~5 d(含水率为44.6%~78.4%)的红花进行采收试验,试验结果表明:在优化参数组合下,红花采净率90.02%,掉落率2.46%,红花破碎率3.04%;在该试验参数组合,对含水率为22.9%~29.5%干花进行采收,出现大量红花残留在果球表面,作业质量急剧下降现象,因此红花适时收获时间为开花期1~5 d为宜。通过在新疆塔城地区裕民县进行红花田间采收试验,表明该采收装置能够满足红花采收的技术要求。上述研究成果丰富了红花采收技术,也为辊式采收机具的设计提供参考依据。

Parameter optimization and experiment of dual roller harvesting device for safflower

Abstract: Because of the growth characteristics of safflower, it is very difficult to realize mechanized harvesting. At present, the mechanized harvesting technology of safflower in China is still in infancy. Most of the current harvesters are divided into 3 types according to their working principle, including the cutting type device, the pneumatic plucking type device and the cutting-pneumatic plucking combination type device. The current harvesting machines have some disadvantages. For example, safflower petals are easily broken and dropped, and safflower fruit balls are easily broken. Therefore, there is no application of 3 types of machines above in safflower harvesting. For the safflower has the characteristics that a single petal is small, light, slim, and easily interfered by air, the research presented a method for safflower harvesting which made use of the negative pressure generated from a pair of high-speed spinning rollers. It achieved the harvesting of safflower mainly by the modes of capture, friction and extrusion. Compared with 3 types of machines above, the plucking device with dual rollers had the advantages of high harvesting rate, and low petal dropping rate and broken rate, so it would be widely applied for harvesting safflower. In order to further study the safflower picking device and improve the work quality for the safflower harvesting device, the dual-roller harvesting testbed was designed. The safflower plucking testbed consisted of plucking unit, driving device, frame and collecting box. The experiment chose the safflower of "Yu Min stingless" as the object. In order to determine the operation parameters of the safflower plucking device, the response surface experiment with 3 factors and 5 levels was completed on the safflower plucking testbed with dual rollers. Three parameters, including roller diameter, dual-roller clearance and rotation speed, were selected as the input variables, and safflower removal rate, dropping rate and safflower broken rate were selected as the output parameters. Quadratic orthogonal rotary regressive experimental design was employed to develop the second order polynomial regression model, which explained the relationship between the input and output parameters. By the Design-Expert 6.0.10 software, the corresponding mathematical regression model was established, the influence of significant factors on the quality of operation was analyzed, and the experimental parameters were optimized. The optimal combination of parameters determined was as follows: roller diameter was 40 mm, dual-roller clearance was 0.5 mm and rotation speed was 1400 r/min. Based on the combination of optimization parameters, the roller clearance was revised as 0.5 mm, and safflower harvesting test was done 1-5 days after the flowering (moisture content ranged from 44.6% to 78.4%). The experimental results indicated that the removal rate was more than 90.02%, the dropping rate was less than 2.46%, and the safflower broken rate was less than 3.04%. However, when the moisture content was in the range of 22.9%-29.5%, the removal rate of the device was less than 19.37%. Therefore, the period within 1-5 days after the flowering was appropriate for the timely harvesting of safflower. Through the field testing of prototype in Xinjiang, the harvesting and laboratory results were basically consistent. This design provides a new reference for mechanical harvesting of safflower, and the study may also provide the basis for mechanism design and parameter optimization of harvesting machine with dual rollers.