Modification of the threshing drum of a stationary thresher to suit separating flax crop [electronic resource].

Includes references.

The aim of the present investigation is to modify the threshing drum of a local stationary thresher (at a private workshop) to suit separation of flax seeds with minimizing the stalks damage. An automatic device for determining the separating times and giving signal after separating the seeds has been designed and fabricated at a private workshop, Kafr El-Sheikh Governorate. The thresher was evaluated and tested at Sakha Agricultural Research Station, Kafr El-Sheikh Governorate under four feed rates of 8.57, 12.86, 17.14 and 21.43 kg/min. and four drum speeds of 24.25, 25.81, 27.33 and 28.85 m/s, two threshing drums of 8 and 12 fingers arranged in five sets each and three separating times of 10, 15 and 20 seconds. Machine productivity (seed output), seeds losses, stalks damage and energy requirements had been determined. The developed thresher productivity, seed and stalk damage, threshing efficiency and energy required for separating flax seeds had been positively affected by both of feed rate, drum speed, number of drum fingers and separating time. On the other hand, the unthreshed seed were positively and negatively affected by the feed rate and drum speed respectively, for the other different treatments. The drum fingers of 12 and separating time of 15 seconds of the developed stationary threshing machine gave the maximum productivity and threshing efficiency and minimum values of seed, stalk damages, consumed energy and criterion costs compared with the drum fingers of 8 and separating times of 10 and 20 seconds. Results showed that development of the threshing drum tended to improve the performance of the stationary thresher, especially productivity and efficiency in addition to decreasing the seed losses and stalk damage compared with the machine before development. The optimum performance for the developed thresher for separating flax seeds was at drum speed of 28.85 m/s, feed rate of 8.57 kg/min. drum fingers of 12 and separating time of 15 seconds. The maximum threshing efficiency of these conditions was 96.92% but the minimum unthreshed seed losses, seed and stalk damage and energy were 1.33, 3.48, 3.26% and 1.262 kW, respectively.

Summary in Arabic.

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