Post Harvest Pesticide Applicator. Josh Schmidt and Josh Martin. ASM, April 20, 2006 Post Harvest Pesticide Applicator Josh Schmidt and Josh Martin April 20, 2006 • Objective: • The purpose of this project was to convert a rotary screen grain cleaner into a rotating pesticide applicator. • The grain cleaner is being used in hopes that farmers could convert their unused equipment for a relatively low cost. • A study by Dave Szabela showed that the current on farm application methods result in uneven coverage and over application. • This applicator will be used to test different parameters such as rotation speed and application rate to determine the most effective parameters for on farm applications.
The first step was to choose the nozzle that would deliver the correct application rate. • The application rate was determined by multiplying the manufacturers application rate by the grain flow into the cleaner. • This unit will be tested at set incoming grain flow rates. After initial data is collected a variable rate controller could be used to adjust the pesticide rate for variances in the grain input. Post Harvest Pesticide Applicator. Josh Schmidt and Josh Martin. ASM, April 20, 2006 • The area that needed to be covered was then measured by turning the machine on and running grain through the cleaner to determine the area that needs to be covered. • A grid was placed on a tarp similar to a spray table, this helped determine the required spray geometry. • This process was also recorded and the video was analyzed to help understand how the grain moves inside the cleaner. • The nozzle geometry was then paired with the flow requirements and nozzles were selected. • After the nozzles were selected the boom had to be placed inside the rotating drum in the correct location. • This was accomplished by cutting a channel out of the front of the cleaner allowing the boom to be supported and not interfere with the rotation of the cleaner. • The outside chamber could not support itself once the channel was cut out. • This problem was solved by installing small wheels on the bottom of the drum to prevent it from sagging. • Metal conduit was used as the boom, this will protect the tubing and provide support for the nozzle.
Post Harvest Pesticide Applicator. Josh Schmidt and Josh Martin. ASM, April 20, 2006 • The cleaner was originally enclosed with a screen to allow fines and foreign material to fall through. • An enclosure had to be made to help contain the spray and take advantage of the grain movement inside the cleaner. • The original plan called for a sheet metal enclosure but it was decided that a clear enclosure material might be beneficial for research purposes. • Plexiglass was used because it was flexible enough to form the size circle needed • Plexiglass long enough to farm the circle was not available so to pieces had to be joined. • The rotation speed of the cleaner will be adjustable. • The original plan was to use a variable frequency drive to adjust the output speed of the motor. • The load put on the motor is to heavy and using this method would cause the motor to prematurely burn out. • This will be addressed by designing a set of pulleys that can be interchanged to obtain different speeds. • This project can now be the basis of further research. • It will be used to determine better methods of post harvest pesticide application hopefully leading to development of a variable rate precision applicator. • This project would be easy and inexpensive to replicate for on farm use.