Study on the Direct Underground Sowing Machine in the Submerged Paddy Field (I)

A Basic Study on the Development of the Sowing Machine

Abstract

This study is on a newly developed device of the seed pipe in the direct sowing machine in the underground sowing of rice seeds in the submerged paddy field.
The main points in structure (Fig. 3) are as follows. Seed pipe comes down vertically from the seed metering device and intersects the horizontal seed pipe. A blower is at one end of the seed pipe and a throttle valve is set to the blower a little way from the intersection. Air blast is utilized through the seed pipe to transport the seeds and set them into the soil under the standing water in the paddy field. It is effective in preventing the clogging in the pipe.
1. Though the seed hopper and the seed metering device are not completely closed, the throttle valve prevents the counter blow of the seeds back into the seed pipe. It makes a low pressure space in the seed pipe which results in smooth passing of seeds down into the seed pipe.
2. The velocity of seeds through the seed pipe varies with that of the blast, the adjustment by throttle valve and the dropping patterns of the seeds to the seed pipe.
3. As the ratio of the seeds in the air blast is small, the seeds are transported uniformly through the pipe if the velocity of the air blast is more than 18m/sec.
4. In order to set the seeds in the soil under the standing water, the seeds need to be spouted out with the velocity more than 10m/sec.
5. According to the test results of the trial machine, the velocity of the air at the spout needs to be more than 17m/sec to prevent clogging in the pipe, but it must be less than 25m/sec to prevent the scattering of the seeds and the disturbing soil surface by the blast.