Design and development of a vertical plate precision seed metering device with positive seed knockout mechanism

Planting of seeds according to agronomical requirements is one of the most important and critical farm operations for crop cultivation. Placing of seeds at proper location is required to maintain plant to plant spacing in a row. A vertical plate precision seed metering device was designed and developed for field pea. Cells with three different depths of 8.48, 8.85 and 9.22 mm and three shapes of 20o, 30o and 40o left side angles were designed to obtain nine different plates. A seed metering device with different plates was fabricated and mounted on experimental setup. Performance of the metering device was evaluated under laboratory condition at three speeds of 37.04, 44.45 and 51.86 rpm. The results showed occurrence of stuck up seeds in the cells and higher missing hills which may be due to non-release of seeds from the seed metering device. In order to seed release from the metring device, a mechanism for positive seed knockout was designed and was incorporated in the developed metering device of different sizes and shapes of vertical plates. The performance of vertical plate precision seed metering device with positive seed knockout mechanism was also evaluated under laboratory conditions. The results showed that cell of 8.48 mm depth and 40o left side angle on a vertical plate seed metering device with positive seed knockout mechanism performed better with lowest average missing index of 2.67%, 0.5% multiple index and highest uniformity of seed placement of 96.83%. Stuck up of seeds in the cells of the seed metering device was not observed after incorporating positive seed knockout mechanism

Design of a Self-propelled Single Row Zero-till Pea Planter for Hills

A self-propelled single row zero-till pea planter was designed for use in hill agriculture in North-east India. An inverted T-type 30 mm wide furrow opener was designed to cut and open the untilled clay soil for planting seeds. The power required to cut the soil and overcome rolling resistance were determined for the design of the furrow opener. A vertical plate seed metering device with positive seed knockout device suitable for pea seeds was used in the planter. The seed hopper was designed to cover an area of 1000 m2 in one filling. A pair of steel rollers was designed to maintain an uniform depth of furrow and covering seeds with soil. A ground wheel was designed to provide power to the seed metering shaft. Accessories, namely the handle, wheels and shaft assembly, main frame and vertical frame were designed for better performance of the planter. The power transmission system was also designed with a belt-tension-type clutch and gearbox to transfer power from the engine to the wheels. A 6.5 kW IC petrol engine was used as a power source. The designed planter was fabricated, and performance of the planter was evaluated under actual field condition using pea seeds at two forward speeds of 0.59 and 0.67 m.s-1 at 60 mm depth of planting. The average seed-to-seed spacing and depth of seed placement were 105.7 mm and 42.5 mm, respectively. The planter could cover an area of 0.06 ha.h-1 with 75.3% field efficiency

Noise exposure in oil mills

Context: Noise of machines in various agro-based industries was found to be the major occupational hazard for the workers of industries. The predominant noise sources need to be identified and the causes of high noise need to be studied to undertake the appropriate measures to reduce the noise level in one of the major agro-based industries, oil mills. Aims: To identify the predominant noise sources in the workrooms of oil mills. To study the causes of noise in oil mills. To measure the extent of noise exposure of oil mill workers. To examine the response of workers towards noise, so that appropriate measures can be undertaken to minimize the noise exposure. Settings and Design: A noise survey was conducted in the three renowned oil mills of north-eastern region of India. Materials and Methods: Information like output capacity, size of power source, maintenance condition of the machines and workroom configurations of the oil mills was collected by personal observations and enquiry with the owner of the mill. Using a Sound Level Meter (SLM) (Model-824, Larson and Davis, USA), equivalent SPL was measured at operator′s ear level in the working zone of the workers near each machine of the mills. In order to study the variation of SPL in the workrooms of the oil mill throughout its operation, equivalent SPL was measured at two appropriate locations of working zone of the workers in each mill. For conducting the noise survey, the guidelines of Canadian Centre for Occupational Health and Safety (CCOHS) were followed. Grid points were marked on the floor of the workroom of the oil mill at a spacing of 1 m x 1 m. SPL at grid points were measured at about 1.5 m above the floor. The direction of the SLM was towards the nearby noisy source. To increase accuracy, two replications were taken at each grid point. All the data were recorded for 30 sec. At the end of the experiment, data were downloaded to a personal computer. With the help of utility software of Larson and Davis, USA, equivalent SPL and noise spectrum at each reading was obtained. Noise survey map of equivalent SPL was drawn for each oil mill by drawing contour lines on the sketch of the oil mill between the points of equal SPL. The floor area in the oil mill where SPL exceeded 85 dBA was identified from the noise survey map of each oil mill to determine the causes of high level of noise. Subjective assessment was done during the rest period of workers and it was assessed with personal interview with each worker separately. Demographic information, nature of work, working hours, rest period, experience of working in the mill, degree of noise annoyance, activity interference, and psychological and physiological effects of machine noise on the worker were asked during the interview. These details were noted in a structured form. Statistical Analysis Used: Nil. Results: The noise survey conducted in three renowned oil mills of north-eastern region of India revealed that about 26% of the total workers were exposed to noise level of more than 85 dBA. Further, 10% to 30% floor areas of workrooms, where oil expellers are provided have the SPL of more than 85 dBA. The noise in the oil mills was dominated by low frequency noise. The predominant noise sources in the oil mills were seed cleaner and power transmission system to oil expellers. Poor maintenance of machines and use of bamboo stick to prevent the fall of belt from misaligned pulleys were the main reason of high noise. Noise emitted by the electric motor, table ghani and oil expellers in all the oil mills was well within 85 dBA. Subjective response indicated that about 63% of the total workers felt that noise interfered with their conversation. About 16% each were of the opinion that noise interfered in their work and harmed their hearing. About 5% of workers stated that the workroom noise gave them headaches. Conclusions: The workers engaged in the workrooms of the oil mills are exposed to high noise, which will have detrimental effect on their health. The poor maintenance of drive system was found to be the main reason for high noise level