Off-Road Equipment Management TSM 262: Spring 2016 LECTURE 20: Grain Harvesting I Off-Road Equipment Engineering Dept of Agricultural and Biological Engineering achansen@illinois.edu

Homework, Lab and exam

Grain Harvesting: Class Objectives Students should be able to: Understand the terminology pertinent to grain combine design and performance Identify and analyze the functional processes for cutting, conveying, threshing, separation and cleaning of grain Evaluate combine harvester performance relative to grain losses

Grain Harvesting Divided into cutting, threshing, separation and cleaning Threshing Breaking grain free from other plant material by applying mechanical force Separation Separating threshed grains from bulk plant material (straw) Cleaning Use air to separate fine crop material such as chaff from grain Combine – single field-going machine that performs all these operations

History Harvesting in its simplest form Recovery of grain from fields Must be done in a given time frame Must maintain the quality of the grain History Manual labor and Early Machines Focus was on cutting and gathering Threshing was done at a later time

History (ctd.) McCormick-Deering introduced combination harvester-thresher ~ 1920 This thresher uses similar processes as modern combines

ASABE Standard S343.3 (Compass) Terminology for combines and grain harvesting Purpose: “establish terminology pertinent to grain combine design and performance” Combine components Crop terminology Combine performance

Functional Processes grain

Functional Processes Thresh and Separate Store Unload Convey Gather and Cut Clean http://www.youtube.com/watch?v=wIvLdIM3pBI&feature=related

Class problems (a) An 8-row combine is operating at 3 mph in 30 inch row corn. If corn yield is 160 bu/acre, compute the time required to fill a 240 bu grain tank (b) A Lexion combine with 16-row corn header is operating at 5mph in 30 inch row corn. If corn yield is 200 bu/acre, compute the time required to fill its 360 bu tank One acre = 43560 ft2 One mile = 5280 ft Note: This does not include time for turning

Solution (a) Given Find time for fill Width = Speed = Corn yield = Grain tank capacity = Find time for fill Work rate = Bushels per h = Time for 240 bushels =

Solution (b) Given Find time for fill Width = Speed = Corn yield = Grain tank capacity = Find time for fill Work rate = Bushels per h = Time for 360 bushels =

Grain harvesting System

Grain Harvesting Process Inputs: grain moisture MOG yield time of day relative humidity cleaning fan speed threshing speed concave opening chaffer opening sieve opening feed rate Outputs: feed rate threshing loss separator grain loss cleaner grain loss grain breakage grain dockage

Definitions Cleaning loss -free grain in the cleaning discharge Tailings MOG - amount of Material Other than Grain in the tailings return system, measured as a ratio of the tailings MOG to the discharge MOG Tailings grain - amount of free grain in the tailings return system, kg/s Grain damage - number of broken grain kernels, measured as a weight percentage Dockage - foreign material in the clean grain, measured as a weight percentage

Functional Processes Gather Cut Convey Thresh Separate straw Clean Header Feeder House Threshing Cylinder Separator Gather Cut Convey Thresh Separate straw Clean chaff Cleaning Shoe grain Unload Store Convey Unloading Auger Grain Tank Clean Grain Auger

Gathering, Cutting and Conveying Most general cutting mechanism is grain table (cutting platform, platform, etc.) Grain Table Reel Auger Sickle

Grain Header Reel keeps material from flowing back out Cutterbar: Sickle, material presented in “hay” lecture applies Auger: Gathers grain toward the center of the header where it can be conveyed into the combine Common Adjustments Reel height, reel speed, header height, reel fore/aft

Grain Header Performance Header losses Shatter losses-grain lost because of reel Cutterbar losses-grain cut by cutterbar but falls to ground Header losses affected by Cutting height Reel position (height, fore/aft) Reel speed Draper Head

1. End sheet 2. Reel 3. Cutterbar 4. Auger 5. Feeder conveyor 6. Threshing cylinder

Finger sensors for cutter bar height control

Gathering, Cutting and Conveying Corn Head Pulls stalks downward Ears catch on “snapping rolls/bars” The spacing on the snapping rolls is wide enough for the stalk to go through but the ear catches and is conveyed into the machine

Feeder conveyor Snapping rolls Gathering chains Gatherer points

Corn header Harvest 4 ~ 18 rows at a time Gathering Chains Moves stalks through snapping zone Conveys loose ears gathering chain speed = forward speed Snapping Rolls Ear is separated from stalk Typical length=1-1.25m;diameter 7.5-10cm Speed of rotation critical

Corn Header Stripper Plates Trash Removal Prevent ears from contacting snapping rolls Opening between stripper plates can be controlled from cab on newer combines Trash Removal Rolls are fluted on upper ends Aids in removal of trash and broken stalks

Caterpillar corn head row unit

Corn Head Corn pulled downward

Corn Head