Development of a Groundnut Decorticator-cum-Grader

Manual decorticating and grading of groundnut pods is a tedious and time-consuming process. Uniformly graded groundnut kernels with minimum breakage increase the value of the product. In the present study, a manually operated rotary-type groundnut decorticator was modified into a combined groundnut decorticating and grading unit by attaching power operated blower and grader to shell groundnut pods and simultaneously separate and grade the kernels based on size in a single continuous operation. The machine integrates decortication, separation, cleaning, and grading mechanisms. The blower separates the decorticated kernels and shell, while the grader separates the kernels into three different grades (small, medium, and large). The performance of the combined groundnut decorticating and grading unit was evaluated with two popular groundnut varieties (viz., K6 and TMV2) to determine the shelling capacity, shelling efficiency, mechanical damage, seed recovery, and grading efficiency. The experiments were conducted in triplicate for both varieties. The data obtained from the physical properties of the two varieties were used for design consideration of blower and grading unit. The shelling capacity, shelling efficiency, mechanical damage, seed recovery, and grading efficiency of K6 variety were found to be 92 kg h^-1, 91.8%, 17.6%, 5.15%, and 91% respectively. Similarly, for TMV2 variety, shelling capacity, shelling efficiency, mechanical damage, seed recovery, and grading efficiency were found as 87.19 kg h^-1, 83.83%, 13.06%, 3.6%, and 86.29%, respectively. The benefit-cost ratio of the developed decorticator-cum-grader was found to be 34.8. The developed groundnut decorticator-cum-grader simultaneously shells groundnut pods and separates the kernels into different size grades, thereby improving processing efficiency, reducing labor requirement, and enhancing the quality, and uniformity of the final product.