GRAIN STORAGE AERATION PRESENTED BY: BRENT BLOEMENDAAL AERATION EXPERT

Transcription

1 GRAIN STORAGE AERATION PRESENTED BY: BRENT BLOEMENDAAL AERATION EXPERT

2 OUR PART condition store harvest use or market

3 CHOICES field dry & store natural air dry & store dryer store dryer store natural air dry store

4 WHAT CHOICES AFFECT condition store harvest timing shelf life grain quality profit use or market

5 ADVANTAGES / DISADVANTAGES Field dry and store No drying and equipment cost It takes a long time to dry down grain in the field which increases exposure and field loss May not get there, risk mold, and incur drying cost at the elevator Natural air dry and store Relatively low drying and equipment cost High cfm/bu fans and low grain depths required Later harvest required to dry down grain in the field which increases exposure and field loss Long time to dry grain in bin with later harvest equilibrium moistures May not get there, risk mold, and incur extra drying cost at the elevator

6 ADVANTAGES / DISADVANTAGES Dry and store Higher drying and equipment cost Minimal field exposure and field loss It doesn t take long to condition grain No elevator drying cost Dry, store, and finish in bin Higher drying and equipment cost Minimal field exposure and field loss Short drying time to get grain safe, then longer time to finish (better drying capacity) Opportunity to optimize efficiencies between dryer and bin moisture removal

7 WHY IS GRAIN STORED? To avoid exposure to the seasonal elements Snow Hurricanes Rain Wind Dryness (grain sold by weight) To use, prep, or maintain the field Double cropping Application of herbicides or pesticides Application of nutrients To get a better price

8 $$$$

9 $$$$

10 over $0.50/bu difference $$$$

11 WHEN SHOULD GRAIN BE HARVESTED? $ $ You do not save money by delaying drying Invisible field loss studies at Purdue and other universities Pioneer newsletter Personal results Lost weight by over-drying in the field Weather gets colder and costs more to dry Extra risk when its not in the bin, protect the investment Start bringing it in as soon as its mature (roughly 26-28%)

12 FIELD LOSS CALCULATOR Incoming moisture Inputs Outgoing moisture 26.0% 15.0% Incoming moisture Selling Price ($/bushel) 20.0% $3.00 Dryer Efficiency (BTU Electrical (cost per lb water) per kwh) 1800 $0.100 Propane Cost/gal Natural gas cost/therm $0.70 $0.60 Projected Dry Bushels Field loss % per % field drydown 100, Field Loss Calculator Results Loss Propane Loss Natural $10,587 $12,068 Incoming moisture Early Harvest Moisture removed 26.0% 11.0% Fuel cost per bu Propane Total drying cost per bu propane $ $ Fuel cost per bu Natural Total drying cost per bu Natural $ $ Electrical cost per bu $ Bushels Sales $ 100,000 $300,000 Drying Cost propane Drying Cost natural $12,303 $9,854 Earnings Propane Earnings Natural $287,697 $290,146 Incoming moisture Late Harvest Moisture removed 20.0% 5.0% Fuel cost per bu Propane Total drying cost per bu propane $ $ Fuel cost per bu Natural Total drying cost per bu Natural $ $ Electrical cost per bu $ Bushels Sales $ 94,000 $282,000 Drying Cost propane Drying Cost natural $4,890 $3, Earnings Propane Earnings Natural $277,110 $278,078

13 WHAT DO YOU DO WITH GRAIN AFTER ITS OUT OF THE FIELD? Dry grain to the right moisture Get it dry enough to avoid dockage, prevent mold, fungi, and mitigate toxins. (drying does not kill mold or toxins, it just reduces what they need to grow) Mold needs 3 things to grow Moisture (above 15.5%) Food (the grain) Stagnant air Keep it wet enough to not lose weight and prevent grain damage (fragility from over-drying and handling) Have a plan How long will the grain be stored? How much moisture do I take out in the dryer? How much moisture do I take out in the bin?

14 OVER-DRYING COST Inputs Results Ideal moisture Overdried moisture Lost Bushels Additional Fuel Cost Propane 15.5% 14.5% 2,339 $2, Test weight Lost Weight Additional Additional Fuel Electrical Cost Cost Natural Gas $ $1, Bushels Overdried Selling Price Additional Drying AdditionalDrying ($/bushel) Cost if Propane Cost Natural Gas 200,000 $3.50 $2, $1, Dryer Efficiency Electrical (BTU per lb water) (cost per kwh) Lost $ for lost bushels 1800 $0.100 $8, Propane Cost/gal Natural gas Total Loss if Total Loss if cost/therm Propane Natural Gas $0.95 $0.65 $10, $9,654.59

15 RIGHT DRYING SOLUTION? Is it the right type of dryer for his operation? In bin solutions Bin heaters, stirring machines Shivvers Stormor etc. How is it working for him? Can the system keep up?

16 RIGHT DRYING SOLUTION? Is it the right type of dryer and drying mode for his operation? Stand alone drying solutions Column style and Mixed Flow Tower, Low Profile, Stacked Full heat Pressure Heat - Pressure Cool Pressure Heat -Vacuum Cool Pressure Heat - Vacuum Cool with Reclaim Grain quality and energy efficiency differences between dryer styles Is there full floor aeration in the bin?

17 DRY RIGHT Dry at the right temperature Capacity differences (5-8% for each 10F between 180F and 240F) Efficiency differences (4% for each 10F between 180F and 240F) Kernel temps must remain below starch gelatinizing temps or kernel swells (test weight) and is discolored. Immature corn, white corn, and some varieties have starches that gel at lower temps. The temp varies between 130F and 152F Go hot as you can without damage

18 FULL HEAT COOLING Approximately 80% of drying on farm is done Full Heat so maximize the moisture removal for the energy spent Efficiency is lost when grain is cooled too fast The energy driving out the moisture from the kernel is the heat of the kernel when it leaves the dryer If the kernel is cooled, that energy is not available to drive the moisture to its surface There must be enough air flow to carry the moisture away from the kernel surface, but not too much to cool it too fast and lose efficiency The rule of thumb is 12 cfm per bushel per hour of dryer capacity

19 Drying Rate (bph) Exit Grain Temp (100 to 160F) cfm per bph (4 to 20) FULL HEAT COOLING Air to cool at Bin Ambient Air Ambient Air Relative Temp Humidity (20 to 95%) (10 to 100F) % bin cfm Grain from Dryer % Moisture possible to bring to the surface Inputs If any of the cells turn red, all the results may be invalid Important outputs % moisture possible for air to carry away Relative Humidity Exit air (%) max 95% Exit air temp (deg F) 12, % 2.02% 53.6% 90 Two basic questions to be answered? How much moisture does the grain have the energy to bring to the surface? Does the volume of air supplied have the humidity ratio capacity to take it away? Conclusion: Any cfm per bph that takes away moisture faster than it is brought to the surface is too much as it robs energy from the process.

20 Drying Rate (bph) Exit Grain Temp (100 to 160F) cfm per bph (4 to 20) FULL HEAT COOLING Air to cool at Bin Ambient Air Ambient Air Relative Temp Humidity (20 to 95%) (10 to 100F) % bin cfm Grain from Dryer % Moisture possible to bring to the surface Inputs If any of the cells turn red, all the results may be invalid Important outputs % moisture possible for air to carry away Relative Humidity Exit air (%) max 95% Exit air temp (deg F) 12, % 4.07% 41.4% 110 Two basic questions to be answered? How much moisture does the grain have the energy to bring to the surface? Does the volume of air supplied have the humidity ratio capacity to take it away? Conclusion: Any cfm per bph that takes away moisture faster than it is brought to the surface is too much as it robs energy from the process.

21 Drying Rate (bph) Exit Grain Temp (100 to 160F) cfm per bph (4 to 20) FULL HEAT COOLING Air to cool at Bin Ambient Air Ambient Air Relative Temp Humidity (20 to 95%) (10 to 100F) % bin cfm Grain from Dryer % Moisture possible to bring to the surface Inputs If any of the cells turn red, all the results may be invalid Important outputs % moisture possible for air to carry away Relative Humidity Exit air (%) max 95% Exit air temp (deg F) 5, % 3.56% 80.7% 126 Two basic questions to be answered? How much moisture does the grain have the energy to bring to the surface? Does the volume of air supplied have the humidity ratio capacity to take it away? Conclusion: Any cfm per bph that takes away moisture faster than it is brought to the surface is too much as it robs energy from the process.

22 COOLING RIGHT Cool it to the right temperature Prevent insects from hatching (54F and below keeps most insects dormant) Freezing when grain has surface moisture can cause clumping Thawing grain with large temperature spreads can also cause clumping Aerate when ambient temps dictate to prevent moisture migration (grain temp within 20F of ambient) Goal is to get the longest shelf life without losing weight

23 SHELF LIFE Calculated days of Shelf life for shelled corn based on USDA research at Iowa State University (0.5% dry matter decomposition) Moisture Content 13% to 28% Temp Calculated 13% 14% days of 15% Shelf life 16% for shelled 17% corn 18% based on 19% USDA research 20% 21% at Iowa State 22% University 23% 24% (0.5% dry 25% matter 26% decomposition) 27% 28% Moisture Content 95 13% to 28% Temp % % % 43616% 24217% % % 20% 99 21% 74 22% 51 23% 37 24% 32 25% 3126% 2927% 21 28%

24 RELATIVE SHELF LIFE Rule Relative to 15% and 50F Temp 13% 14% 15% 16% 17% of thumb for this range: Every 1% reduction in dryness nearly doubles shelf life Every 10F cooler is about a 1.8X

25 CUMULATIVE SHELF LIFE Cumulative Shelf Life Calculator Storage Inputs Days Result % % Days Condition 1 Temp 35 Moisture 15.4% Used 180 Shelf life 856 Used 21% Rem 79% Rem % % 55% % % 44% % % 26% % % 18% 72 Have a plan!

26 MOISTURE MIGRATION Cold air on bin wall and in headspace with natural circulation flows downward There is warm grain in the center of the bin The cold air picks up heat and moisture as it rises through the warmer grain Moisture condenses on colder grain Grain is wetter where it condenses and mold starts

27 MOISTURE MIGRATION Temp and % Relative Humidity Sioux Falls, SD Weather Data 2016 Temp Theo Temp summer winter winter Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month Suggested aeration schedule based on grain temp and ambient temp alone* Try to keep grain within 20F of the average daily ambient to avoid moisture migration *This does not take into consideration Equilibrium Moisture

28 GENERAL PRINCIPLES Aeration bottom line principles: You need to aerate to prevent moisture migration so air is not stagnant for long periods of time or you will have mold and when you aerate the grain, the moisture will change with the temperature and humidity of ambient air (its equilibrium moisture)

29 AERATION PRINCIPLES HUMIDITY RATIO (LBS WATER /LBS AIR) Ability of air to carry water at full saturation AIR TEMP (DEG F) Air can hold a lot more water as the temp increases. The size of the bucket is determine by the temp. Rule of thumb: The air can hold twice as much water for every 20F temperature rise

30 Ability of air to carry water at various temperatures and relative humidities AERATION PRINCIPLES Relative Humidity: How full is the bucket? HUMIDITY RATIO (LBS WATER /LBS AIR) % 30% 40% 50% 60% 70% 80% 90% 100% RELATIVE HUMIDITY (%) Rule of thumb: The relative humidity changes 25% for a 10F change in temperature

31 AERATION PRINCIPLES Equilibrium moisture: The set of conditions where further aeration with air of a constant relative humidity and temperature does not change the grain moisture The grain moisture at which the partial vapor pressure of the water in the air and the grain are equal If the grain partial vapor pressure is higher, moisture will leave the kernel till the pressure is the same If the air partial vapor pressure is higher, moisture will added to the grain

32 AERATION PRINCIPLES Equilibrium moisture for Shelled Corn from calculation Air Relative Humidity (%) Temp

33 AERATION PRINCIPLES Calculated EQM 30F 40F 50F 60F 70F 80F 90F 100F EQUILIBRIUM MOISTURE % RELATIVE HUMIDITY %

34 WHAT HAPPENS? If I add heat: The water in the grain has more energy to push out moisture The air can carry more water the temp goes up and the relative humidity goes down (both lower the equilibrium moisture) If I remove heat: The reverse is true Heat A small temperature difference goes a long way

35 AERATION PRINCIPLES Equilibrium moisture: Changes throughout the day Changes with the season Pattern is the same regardless of geographic location Controllers optimize EQM statistics and run aeration when the conditions are right

36 AERATION PRINCIPLES 48 hr. Sioux Falls Equilibrium Moisture October Equilibrium Moisture (%) average Theo Cosine +9 degf sends worst Theo EQM to 15.0% (+10.3 gets the peak) -9 degf sends worst EQM to 15.0%(-21.6 gets the peak) Average Temp 49.7F Average RH 69% Average EQM 16.5% Time (Hours)

37 AERATION PRINCIPLES 48 hr. Jackson MS Equilibrium Moisture 7-8 September Average Temp 81.3F Average RH 70% Average EQM 14.5% degf sends worst Theo EQM to 15.0% (+6.4 gets the peak) 18.0 Equilibrium Moisture (%) average Theo Cosine -14 degf sends worst avg EQM to 15.0% (-29.1 gets the peak) Time (Hours)

38 Temp and % Relative Humidity AERATION PRINCIPLES Sioux Falls, SD Weather Data 2016 Temp Rel Humidity Theo Temp 22.0 Theo Humidity EQM Theo EQM Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month Eqilibrium Moisture

39 IF I ADD HEAT? Anything more than about 10F means you are over-drying the bottom to get the top of the bin to the right moisture Larger bins make stirring machines impractical If I add heat to my aeration how do I know how much to add without over-drying? Use the graphs or charts to: 1. Determine the equilibrium moisture before adding heat 2. Determine how much water the unheated air is holding 3. Determine how much the relative humidity changes for each 10F 4. Determine the temp and relative humidity to get to the desired EQM Heat A small temperature difference goes a long way

40 TEMP CHANGE TO AERATION AIR I have ambient air at 45F and a relative humidity of 80%. How much heat do I need to add to get to 15.5% EQM? Step 1: What is the current EQM? Air Temp change at present Humidity Ratio for a desired EQM (limited F & %RH) Temp 1 Relative Hum1 Desired EQM 45 80% 15.5

41 AERATION PRINCIPLES Calculated EQM 30F 40F 50F 60F 70F 80F 90F 100F EQUILIBRIUM MOISTURE % desired EQM current EQM RELATIVE HUMIDITY %

42 TEMP CHANGE TO AERATION AIR I have ambient air at 45F and a relative humidity of 80%. How much heat do I need to add to get to 15.5% EQM? Step 1: What is the current EQM? Step 2: How much water is the air holding (lbs. H2O / lb. air)? Air Temp change at present Humidity Ratio for a desired EQM (limited F & %RH) Temp 1 Relative Hum1 Desired EQM 45 80% 15.5 EQM

43 AERATION PRINCIPLES Ability of air to carry water at various temperatures and relative humidities HUMIDITY RATIO (LBS WATER /LBS AIR) At 45F: A 10F change in temp means a 28% change in relative humidity % 30% 40% 50% 60% 70% 80% 90% 100% RELATIVE HUMIDITY (%) 30

44 TEMP CHANGE TO AERATION AIR I have ambient air at 45F and a relative humidity of 80%. How much heat do I need to add to get to 15.5% EQM? Step 1: What is the current EQM? Step 2: How much water is the air holding (lbs. H2O / lb. air)? Air Temp change at present Humidity Ratio for a desired EQM (limited F & %RH) Temp 1 Relative Hum1 Desired EQM 45 80% 15.5 EQM Humidity Ratio Step 3: Find the temp and relative humidity of the air to get to 15.5% EQM

45 AERATION PRINCIPLES Calculated EQM 30F 40F 50F 60F 70F 80F 90F 100F EQUILIBRIUM MOISTURE % desired EQM current EQM Line has slope of 28% relative humidity for each 10F Where line crosses 15.5% is the answer RELATIVE HUMIDITY %

46 TEMP CHANGE TO AERATION AIR I have ambient air at 45F and a relative humidity of 80%. How much heat do I need to add to get to 15.5% EQM? Step 1: What is the current EQM? Step 2: How much water is the air holding (lbs. H2O / lb. air)? Step 3: Find the temp and relative humidity of the air Air Temp change at present Humidity Ratio for a desired EQM (limited F & %RH) Temp 1 Relative Hum1 Desired EQM 45 80% 15.5 EQM 1 Humidity Ratio Temp Temp Change 4.4 Temp 2 Relative Humidity 68%

47 THANK YOU