Investigation of Engineering Properties of Black Gram and Horse Gram for the Design of Hopper and Seed Plate of a Pneumatic Planter

Study presents an in-depth evaluation of the engineering properties of Black Gram (Vigna mungo) varieties VBN-6 and ADT-5, and Horse Gram (Macrotyloma uniflorum) varieties KS-2 and Paiyur-2. This is carried out for the design of a pneumatic seed metering unit viz., seed plate and the hopper. Emphasizing the importance of physical and engineering properties, the investigation on moisture content, axial dimensions, gravimetric properties, and key engineering characteristics such as density, porosity and frictional properties provides critical data for optimizing the design and functionality of the pneumatic seed metering unit, including the seed plate and hopper. For black gram, metering plates with 2.1 mm cell diameter were found optimal, whereas horse gram varieties require 3.5 mm diameter with 26 cells. Hopper of 9100 cm3 capacity made of mild steel of 2 mm thickness was developed according to the seed bulk density and flow characteristics. These properties made the pneumatic metering mechanism compatible with pulse seeds and helped to mechanize the pulse sowing.