360 likes | 915 Views
ADJUSTING THE FORAGE HARVESTER FOR CORN SILAGE PARTICLE SIZE. Ronald T. Schuler, Professor Extension Agricultural Engineer Biological Systems Engineering Department University of Wisconsin-Madison. Team Forage. Corn Silage Particle Size-Factors. Machine Adjustment
E N D
ADJUSTING THE FORAGE HARVESTER FOR CORN SILAGE PARTICLE SIZE Ronald T. Schuler, Professor Extension Agricultural Engineer Biological Systems Engineering Department University of Wisconsin-Madison Team Forage
Corn Silage Particle Size-Factors • Machine Adjustment • Feed roll and cutterhead • Crop processor • Crop maturity • Storage • Animal
Forage Harvester • Functions: • Gather the crop • Size the crop, primarily length of forage particles • Deliver crop to transport unit
Typical Configuration • Crop Unit • Hay head or row crop • Feed rolls • Compressing material for cutting • Determining TLC • Cutterhead • Chopping material • Crop Processor • Crop damage • Blower
Typical Configuration of Pull Type Harvester Processor Feed rolls Cutterhead Auger
Feedrolls • Typically two sets • Larger, front set for feeding • Smaller, rear set to meter material into the cutterhead • Bottom rolls are fixed • Can contain metal detectors • Top rolls float • Spring pressure to grip material
Feed rolls • controls the rate of feeding into cutterhead • compresses mat of material so it is easier to cut
Theoretical Length of Cut • Definition - feed roll travel per knife • Recommendations • Dependent on • Animals • Feed handling equipment • Crops • Corn silage - 3/8 in.(no crop processor) • Corn silage - 3/4 in.(crop processor)
Theoretical Length of Cut • Adjusting theoretical length of cut • Feed roll speed • Number of knives • Cutterhead speed • Not practical
Actual Length of Cut • Longer than the TLC • Windrowed crops longer than row crops • Alfalfa feeds in a tangled mat of material • Corn stalks feed mostly straight
Blower Crop Processor Cutterhead Feed rolls Crop Processor
Crop Processing • Used only for whole plant corn silage • Kernels are difficult to digest • Contain starch and energy • Damaging the kernel shell allows the rumen bacteria to digest the starch • Breakup cob pieces (avoid hockey pucks)
Crop Processing • In the past, very short lengths of cut were used to damage more kernels • Recutter screens also used • Increased power requirements drastically • Shortened fiber length too much
Crop Processor Characteristics • 1 – 15 mm (1/16 to 5/8”)-clearance range • 5 – 25% speed difference • Speed 2500 – 4000 RPM • 3 – 6 grooves per inch
Crop Processing A properly adjusted kernel processor • Damages more than 90% of the kernels • Pulverize cob pieces • Minimizes waste in the feed bunk • Allows for longer length of cut • Longer fiber • Less power consumption
Crop Processor Clearance Adjustment
Crop Processing System Cutterhead Processing Rolls
Differential speed between rolls
Crop Processor - Tips for Success • Increase the theoretical length of cut (TLC) to ¾” • Processor will reduce overall particle size further • Set roll gap between 0.08” and 0.12” (2-3 mm) • Will result in 100% cob breakage and 90-100% kernel damage
Don’t crop processors take A LOT of extra horsepower?? Not if set up properly! • Power consumption for • 3/4” TLC and a processor set to 0.20” (2.70 Hp-hr/ton) is only slightly higher than • 3/8” TLC with no processor (2.69 Hp-hr/ton)
Roll Wear • PTFH - Rolls Wear At Center • SPFH - Rolls Wear At Edges • Helical Knives - Uneven Wear • As Teeth Wear: • Capacity Is Reduced • Plugging More Likely • Processing More Difficult
Dealing with Worn Rolls • Replacement ~ $1,500 per Roll • Re-Grooving ~ 1/3 to 1/2 Cost of New • Re-Grooving Considerations: • Won’t Last As Long As Original • Can Only Be Done Once • Tolerances Not As Good
WHAT TO LOOK FORIN A CROP PROCESSOR • Roll Diameter • Tooth Pitch • Ease of Checking and Adjusting Roll Clearance • Ease of Unplugging • Ease of Switching Between Corn silage and Haylage
Machine Power Consumption • Gathering and feeding • 20% of total • Cutterhead and processor • 40 – 50% of total • Blowing into wagon / truck • 30 – 40% of total
Reducing Power Loss • Maintain sharp knives • Keep close knife to shearbar clearance • Properly adjust processor • Keep blower band clearance small
Concluding Remarks • No Processor-TLC=0.375 in. • Processor-TLC = 0.75 in and roll clearance= 0.8 to 0.12 in.