Combines Getting barley clean

Farm_Kid2

Guest
If you don't want to put the air deflector in I would take a peice of tin about 18" long and cover the front of the chaffer (or do something to block it off) and then crank the fan speed up untill you blow the chaff out the back of the machine, but the grain stays in. How fast can you get the fan speedIJ It might need to be as high as 1100 or moreIJ Make sure the fan cutoff (a metal flap that runs the full width of the fan) is in place and properly adjusted. You will probably end up with the lower sieve closed down quite a bit from what the book says. You'll know it's closed too far when you start plugging the return elevator. If you open the return elevator drain while the machine is loaded, what is in thereIJ Is it fullIJ Is it mainly fluffy threshed material like chaff or do you have unthreshed headsIJ Mike
 

Dath

Guest
Mike, I had my fan speed upto 1220 and was blowing grain out of the back. The returns were full of grain and fines but no unthreashed heads. I closed the cleaning sieve to the point that the unthreahed heads stopped falling into the tank. Are the pieces of straw falling into the clean grain as the material comes off the grainpanIJ Do I need to change the rotor setupIJ Do you have any experence with the air deflectorIJ Kenneth
 

Farm_Kid2

Guest
You really aren't blowing the grain out the back like you think you are. What is happening is the blast of air coming out of the fan is pointed upward and into the front of the chaffer. As you increase the fan speed the air velocity is so high that is launches grain from the front of the chaffer clear out the back of the machine. This is probably worse for a light crop like barley. At the rear of the chaffer the air velocity is much lower allowing the chaff to fall through the chaffer and into either the grain tank or the return. We have put the fan deflector in three machines now, and won't go to the field without it. It gets the air flow evened out from the front to the rear. I'm confident that it will make a huge difference for you if your tank and_or return is full of light, fluffy material. Hate to tell you this, but the crossflow fan actually makes the problem worse. Your old fan does not blow as vertical as the new one, but they both need the deflector. Here's the link.
 

John_W

Guest
Do you have many unthreshed headsIJ Do you have any rotor lossesIJ Sounds like your grinding up the straw and then have a problem cleaning things up. Which position are the vanesIJ Maybe you could lighten the MOG load on the chaffer by fiddling with the rotor speed, concaves, transport vanes and reducing returns if they are excessive.
 

tj

Guest
Quick experiment -- Wire some heavy cardboard (about 10" wide) on top of the very front of the chaffer, well enough that it can't blow off. This should spread the air somewhat, and prevent trash from being forced thru the front of the chaffer. Also should allow the chaffer to be opened more than present in order to reduce the airspeed at the chaffer surface caused by the venturi effect of the pinched down fingers -- should help prevent blowing over. Are you leaving the stubble fairly tall and spreadingIJ If this is the case, the fan may be picking up trash and blowing it under the sieves when you turn corners. You'll also sometimes see this in windy conditions, as well.