Multiple Attributed Parametric Review Study on Mechanical Cotton (Gossypium hirsutum L.) Harvesters

Crop characteristics of cotton are crucial to identify the important crop attributes like plant height, canopy width, sympods and monopods distribution, row spacing which affects the performance of mechanical harvesters. The activity and effectiveness of most harvest aids, including desiccants is reduced by low temperature conditions. Trash content was observed to be lesser in cotton harvested by cotton picker than cotton harvested by cotton stripper. It was found that a maximum cotton yield of 1000 kg acre-1 was obtained for a cotton plant population ranging between 45,000 and 90,000 plants acre-1. Likewise, a minimum of 700 to 740 kg acre-1 was observed for a cotton plant population of 33,000 plants acre-1. In higher yielding cotton, cotton pickers recorded higher picking rate than cotton strippers. Picking/harvesting efficiency of cotton stripper with both finger and brush type mechanism was higher than the spindle type cotton picker. Picking efficiency of pneumatic picker was higher than the other types of picking mechanisms, but with lesser rate of picking capacity. Gin turnout of cotton was higher with cotton picker when compared with cotton stripper due to lesser trash content in picker harvested cotton. The horsepower requirement of cotton stripper ranged from ½ to ¼ horsepower and cost is about two-thirds of the price as compared with cotton picker. The scheduling and monitoring of various activities involved in cotton picking by using a suitable software model can increase the benefits of both growers and harvesting companies. The reduction in uniformity with roller gin-type lint cleaners ranged between 0.2 to 0.8%, which was lesser as compared with saw-type lint cleaners. Introducing mechanical harvesting has always been a decades-long process. In Turkey, it took 20 years and in Greece, this process took place very gradually over a 15-year period. Top cotton producing countries like India, Pakistan, China, Uzbekistan and other developing countries like Iran Paraguay are still not using machine harvesting. The introduction of mechanical cotton picker or stripper can help improve quality and quantity of cotton picking thereby giving more benefit to growers in developing countries and improving their socio-economic status. The most controversial issue raised by the introduction of the mechanical cotton harvester is great migration as the machines eliminated jobs and forced poor families to leave their homes and farms in search for urban jobs. Therefore Government policies towards cotton harvesting mechanization must include the alternative jobs, packages for dependent manual cotton pickers and their families.

Influence of the circumferential speed of the spiked cylinders on the efficiency of cleaning raw cotton

The article examines the dependence of the speed of rotation of the spiked cylinder of the machine for cleaning the raw cotton from fine impurities on the cleaning efficiency of the machine by different varieties. In addition, the article plotted the speed of rotation of the spiked cylinder as a function of mechanical damage to the seed. Based on experimental studies, the operation of the machine for cleaning cotton raw materials from fine contaminants is based. Experimental studies on raw cotton of medium and fine fiber varieties of hand and machine cotton picking on the value of constant and differentiated peripheral speeds of cylinders fully confirmed the theoretical conclusions. It is recommended to use a differentiated high-speed mode of rotation of the spiked cylinders: When cleaning medium-staple cotton - 10:11:12 m/sec, when cleaning fine-stapled cotton - 9:10:11 m/sec.

POSSIBILITY TO ENSURE THE TECHNICAL EFFICIENCY OF THE VERTICAL SPINDLE COTTON PICKER

In order for the use of the vertical-spindle cotton picker, created in Uzbekistan, to be economically effective, it is necessary, first of all, to increase its completeness of harvest. This indicator depends on many factors. However, the most important factor is that the spindle friction drive function is inadequate. Friction forces between the friction drive belts and the spindle roller determine its tagging capacity. The magnitude of the friction force depends on the pressure of the belts on the roller, which in turn depends on the tension of the drive belts. The article analyzes how much the tension of the drive belts in economic conditions meets the requirements.Key words:completeness of cotton picking by the apparatus; friction drive; belt tension; traction ability; direction and magnitude of the absolute speed of the spindle tooth; moment of power; variability of the angular speed of the spindle; gripping power of the tooth

Electrostatic separation motion analysis of machine-harvested cotton and residual film based on CFD

A solid model of electrostatic separation between mechanical cotton harvesting and residual plastic film is established. The mechanized harvesting degree has been improved year by year. 90% of the cotton harvesting has been achieved in the southern Xinjiang reclamation area of Xinjiang Production and Construction Corps. However, there are a lot of impurities in the machine harvesting cotton, and it is difficult to remove them. Machine-picked cotton cleaning is an important part of cotton processing. Its cleaning effect directly affects the processing efficiency and lint quality of cotton. In this paper, a solid model of electrostatic separation between mechanical cotton harvesting and residual plastic film is established. Through CFD method, the particles of mechanical cotton harvesting and residual plastic film fly into the electric field at the speed of 3 m/s, 4 m/s, 5 m/s and 6 m/s respectively, and the movement process of different electric field forces is loaded on the particles, in order to reveal the mechanism of electrostatic separation between mechanical cotton harvesting and residual plastic film. The test results show that with the increase of the speed of cotton picker flying into the electric field area, the shorter the residence time of cotton picker in the electric field area, the electric field force required for the film to be captured by the upper plate will gradually increase; the trajectory of particles in the electric field area has less influence on the airflow, and the inlet airflow velocity is the most important factor affecting the airflow distribution in the box. This study is expected to provide a reference for the application of electrostatic technology in the study of the cleaning process of mechanical cotton picking.

Wear Behavior of Spindles of Cotton Picker in Field Work

Spindles in cotton picking machinery are the key component, wear of the spindles significantly reduces harvest efficiency of the cotton picking process. To improve its wear resistance, the substrate surfaces of spindles are usually electroplated with chromium coating. But the failure process and wear mechanism of the spindle have not been studied so far. In this paper, based on the surface analyses and wear behavior of spindles of a cotton picker in field work, the test results showed that the worn surface was smoother and wear trend of surface topographies tend to consistent along with the rotation direction of the spindle and found a significant reduction in roughness and coating thickness. The coating of the spindle surface has not been damaged in the picking process, the wear mechanism was mainly abrasive wear. After the worn out of surface coating, abrasive wear is always present accompanied by oxidation wear. Multi-oxides were deposited on the substrate surface; the oxide particle was sheared by cotton fiber in the subsequent picking, leading to an increase in surface roughness and aggravating substrate wear. These in filed wear mechanisms and processes of spindles could be of help for the design and surface modification with longer working life.