| This paper focally states the study and Study and test analysis on the one-step Seed-centralized pneumatic drill on the basis of analyzing China current wheat-planting policy, the cultural techn- ique of drill sowing and the present situation of correspond- ing pneumatic drill.Wheat takes a decisive place in agricultural production of our country. For many years, sown area of grain has been decreasing little by little, while that of wheat has been gradually increasing. For China, raising output of wheat plays a key role in solving tens hundreds million of people's life conditions.With the development of wheat-planting technique, wheat planting mechanization is developing rapidly as well. Take our province as an example, general farm machinery power reached 7685.57KW. The level of mechanical seeding reached 39.16%. By and large, wheat-drill also takes dominating role in agriculture planting and suited seed drill is also been taken into practice. At present grain drills generally take fluted feed as their core parts, but its structure is complicated, coherence in each row is poor. Conical-dish wheat precision drill applied less improves in the way of distributing equality, but its staving rate reaches 20%. Thus it affects the rate of emergence seriously and cannot realize the demand of semi-precision drilling. Both of above drills exit many questions, such as "one dispenser one row", complicated structure and poor coherence in each row and so on. Therefore, itis necessary that developing a new kind of efficient drill. One-step seed-centralized pneumatic drill takes air current as carrier, realizing fix quantify mechanically and one-step multi-rows air seeding working. Its core parts Seed-centralized system is consist of fan, seed box, fluted feed, eject enricher, pipes, center air distributor and so on. Fan is driven by PTO of tractor suited with drill and provides energy to the whole seed-centralized system. Fluted feed is driven by wheel with chain wheel transmission, distributing seeds to the seed-centralized system quantificationally. Seeds are sucked into the pipe where exits minus pressure by eject enricher. After entering into supercharger pipe, seed-air mixture produces backset and pressure increase. Finally, seed-air mixture expel from center air distributor under effect of centrifugal force.The precondition that air current can carry seeds is the air velocity is larger than that of the suspend velocity of materiel. In order to ascertain the movement form of seeds in pipe, we make kinetic analysis to seeds in pipe. We make sure movement equation of the seeds and study pressure expense. First we presume feeding rate, ascertaining the velocity of air current, ascertaining the feeding quantity by farm technical demand and ascertaining wind quantity, calculating the diameter of pipe. By calculating pressure expense, we ascertain the working pressure of fan. Because many factors affect the capability of the system, we have to calculate the data over again while changing anyone of factors. In order toavoid complicated manual work, penman programme pressure expense with VB language. User only input some basic parameter, the computer can complete complicated calculating works. Thus, complicated calculating works originally become easy as well as shortcut.By studying the form of center air distributor, we ascertain typeâ…¡ center air distributor which cannot produce backset and backair and ascertain its structure size. In order to observe and design more easily, penman protracted three-dimensional drawing.We determine the suspend velocity of seeds used in test, verifying air velocity presumed formerly and ascertain air velocity in pipe. Reviewing the guideline affected capability of seed-centralized system, we ascertain affected factors: rotate speed of fluted feed, air velocity, radius of curving pipe, length of vertical pipe, length of supercharger and screw pitch of supercharger. We verified wind quantity and pressure of fan by testing. As a result, the wind quantity of...
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