Design and experiment of 1MCDS-100A typed shovel-sieve residual film recovery machine

Abstract: Plastic mulching planting pattern is usually adopted when planting peanut, cotton and other crops in modern agriculture, and the planting soil type is mostly in sandy soil or sandy loam with good fragility. As more and more residual membrane left in the field surface, accumulation of the residual film which is not clearly picked up all the year round, causing serious "white pollution". Taking typical croplands in North China for example, it is estimated that, the quantity of residual film in peanut and cotton fields would reach up to 69.1 and 70.4 kg/hm2 by 2021, If we do not pay attention to the recovery of residual film, these areas would become the pollution area contaminated by residual plastic membrane. In order to solve serious pollution of residual plastic film left in the field after harvest, several residual film recovery machines are commonly used, such as tooth type (spike tooth, elastic claw, telescopic tooth, etc.), curl-up film roller type, shovel-chain type, and multi-function duplex machinery, but both domestic and international shovel-sieve type residual film recovery machines which adapt to sandy soil have been rarely reported. First, the current sieving surface had no structural design of blocking glide in the process of screening, while film, soil and impurity substance could easily cause soil accumulation because of its own gravity, leading to the clogging of sieve holes with low membrane separation efficiency. Second, the step by step transmission ability of vibration sieve was poor, causing residual film winding, membrane leakage, reversing and other issues. In addition, most of the existing shovel-screen type residual film recycling machines had only one single sieve. As such cleanliness of recycled residual film needs to be improved. At the same time, in order to reduce vibration, the existing eccentric drive arm equipment was often equipped with rotary parts when screening, such as the eccentric block, flywheel or other parts, but rotary motion of chosen rotary parts could not eliminate the reciprocating movement of sieve, causing large vibration in the process of machine operation, high labor intensity of drivers and poor stability of machinery. In order to reduce vibration in the operation of shovel-sieve type residual film recycling machine, in this study, a up and down parallel arranged double-sieve type self-balancing residual film recycling machine was designed, rotation speed of drive shaft was determined, ranging from 260 to 330 r/min, a DH5902 dynamic testing system was used. A field experiment was carried out to test the vibration parameters of the double-sieve residual film recycling machine and the experimental results showed that vibration frequency from 3 to 5.5 Hz, horizon vibration measurement value of the frame was 4.2-5.4 m/s2, among which the equipment could withstand, the damping effect of double-sieve residual film recycling machine was obvious, five sieves with different sieve surface structures including the bar sieve, cross bar sieve, wire gauze sieve, round hole sieve and saw-tooth sieve were tested by single factor experiment. Finally, saw-tooth sieve was determined as the optimal sieve form. Moreover, an electric pushing rod typed automatic film uploading device was designed, film collecting basket completed the unloading task in 4.1 s, solving longtime labor issues currently exist in uploading link. Machine forward speed, vibration frequency of saw-tooth sieve, amplitude of saw-tooth sieve and saw-tooth distance were selected as experiment factors. The response surface method was used, and the effect of each factor influenced on the targets of the residual film recycling was analyzed by drawing four-dimensional chip figure on Matlab2013a software. The experimental results showed that the test factors had a great influence on residual film recovery quality. The optimal parameter combination was obtained: machine forward speed was 0.73 m/s, amplitude of saw-tooth sieve was 99 mm, vibration frequency of saw-tooth sieve was 280 r/min, saw-tooth distance was 12 mm, when the recovery rate of residual film was 91.26%, rate of winded film was 4.27% and film soil ratio was 2.16. It met the requirements of the residual film recycling quality. This study not only supplies the residual film recycling market with a both urgent and practical tool, but also provides theoretical basis and reference for the innovation development and optimization of plastic film recovery machinery.