AERATION AERATION and COOLING and COOLING of Stored Grain of - PowerPoint PPT Presentation

AERATION AERATION and COOLING and COOLING of Stored Grain of Stored Grain Mark Casada , Ph.D., P.E. , Ph.D., P.E. Mark Casada Agricultural Engineer Agricultural Engineer USDA – – ARS ARS USDA Grain Marketing & Production Grain Marketing & Production Research Center Research Center Manhattan, Kansas Manhattan, Kansas IAOM Pest Management Workshop IAOM Pest Management Workshop

Professional Experience Professional Experience crop storage & handling 20+ years: crop storage & handling 20+ years: GMPRC research and teaching research and teaching 1981: 1981: B.S. Mechanical Engineering (P.E.) B.S. Mechanical Engineering (P.E.) 1980s: 1980s: corn, tobacco, peanuts (Ky. & NC) corn, tobacco, peanuts (Ky. & NC) 1990s: 1990s: wheat, barley, & potatoes (Idaho) wheat, barley, & potatoes (Idaho) 2000s: 2000s: wheat, corn (Kansas) wheat, corn (Kansas)

AERATION AERATION and COOLING and COOLING of Stored Grain of Stored Grain • Introduction… Grain Storage Basics Introduction… Grain Storage Basics • � Grain Moisture: affect on storage � Grain Moisture: affect on storage • Grain Temperature & Cooling Grain Temperature & Cooling • • Grain Aeration Systems Grain Aeration Systems •

Grain Storage Grain Storage The Good New s: The Good New s: Cool, dry, clean grain stores very well: grain stores very well: Cool, dry, clean we expect no quality loss no quality loss. . we expect Aeration is the tool to keep grain cool: Aeration is the tool to keep grain cool: Alw ays below 6 0 ° F, Alw ays below 6 0 ° F, below 5 0 ° F w hen w eather allow s. below 5 0 ° F w hen w eather allow s.

Grain Storage Grain Storage The Bad New s (grain storage threats) (grain storage threats) : : The Bad New s � Insects Insects � � Fungi (molds) Fungi (molds) � � Sprouting Sprouting � � Loss of Germination Loss of Germination � � Handling Damage Handling Damage � � Rodents and Birds Rodents and Birds � � Other (Spoutlines, Moisture Migration, …) Other (Spoutlines, Moisture Migration, …) �

Grain Storage Grain Storage The Bad New s (grain storage threats) (grain storage threats) : : The Bad New s � Insects Insects � � Fungi (molds) Fungi (molds) � � Sprouting Sprouting � � Loss of Germination Loss of Germination � � Handling Damage Handling Damage � � Rodents and Birds Rodents and Birds � � Other (Spoutlines, Moisture Migration, …) Other (Spoutlines, Moisture Migration, …) �

Stored Grain Factors Stored Grain Factors Cool Cool � Temperature Temperature � Dry Dry � Grain Moisture Content Grain Moisture Content � � Initial Grain Quality Initial Grain Quality Clean Clean � – soundness soundness – – degree of contamination (fungi, insects, …) degree of contamination (fungi, insects, …) – – amount of foreign material amount of foreign material – � Time in Storage Time in Storage � � Other (Oxygen Supply, pH, …) Other (Oxygen Supply, pH, …) �

Stored Grain Factors Stored Grain Factors � Temperature Temperature � � Grain Moisture Content Grain Moisture Content � � Initial Grain Quality Initial Grain Quality � – soundness soundness – – degree of contamination (fungi, insects, …) degree of contamination (fungi, insects, …) – – amount of foreign material amount of foreign material – � Time in Storage Time in Storage � � Other (Oxygen Supply, pH, …) Other (Oxygen Supply, pH, …) �

Dealing with the Threats Dealing with the Threats The Top Two Threats The Top Two Threats � Insects Insects � control w/ temperature control w/ temperature � Fungi (molds) Fungi (molds) control w/ moisture � control w/ moisture

GRAIN MOISTURE GRAIN MOISTURE

Dry vs. Wet Grain Dry vs. Wet Grain � For this lecture: For this lecture: � – Emphasis on dry grain (or over Emphasis on dry grain (or over- -dry). dry). – Moisture problems usually very limited. � Moisture problems usually very limited. � – Insects usually the bigger issue Insects usually the bigger issue – (temperature). (temperature). Low moisture content may slow or stop � Low moisture content may slow or stop � some primary infesting insects. some primary infesting insects.

Grain Moisture Equilibrium Grain Moisture Equilibrium 25 Corn Moisture Isotherm (68°F) Equilibrium Moisture 20 Content, % 15 10 5 0 0 20 40 60 80 100 Relative Humidity, %

Grain Moisture & Mold Control Grain Moisture & Mold Control � Moisture Content Moisture Content � Max. the key to mold the key to mold Storage Mold control control Growth Corn at 68°F Corn at 68°F 65% 65% M.C. ERH M.C. ERH Min. 16 % 79 % 16 % 79 % 60% 70% 80% Relative Humidity, % 15 % 73 % 15 % 73 % 14 % 66 % 14 % 66 %

Safe Storage Moisture Content Safe Storage Moisture Content Grain Stored One Year South Central North Corn/Milo 13 14 14 Soybeans 12 12 13 Wheat/Barley 11 12 13 Sunflower 9 9 9

Grain Moisture Grain Moisture Average Moisture Content – – Average Moisture Content Very little grain is at the “average” Very little grain is at the “average” moisture content moisture content Must deal with the highest Must deal with the highest moisture content in the bin moisture content in the bin

Grain Moisture Grain Moisture Moisture migration Moisture migration Wet grain causes additional causes additional moisture variation moisture variation Warm Cold Grain Air Aerate to eliminate Aerate to eliminate temperature differences temperature differences

Grain Moisture Grain Moisture Watch for Watch for Wet grain “simple problems” “simple problems” A leak is a leak… A leak is a leak…

Grain Moisture Grain Moisture Watch for Watch for Wet grain “simple problems” “simple problems” Spouting can channel Spouting can channel leaking water… leaking water…

GRAIN TEMPERATURE GRAIN TEMPERATURE

Temperature & Insects Temperature & Insects Max. Temperature Temperature Storage Insect Growth is the key is the key to to 60°F 60°F insect control insect control Min. 60 70 80 90 Temperature, °F

Temperature & Insects Temperature & Insects 90 90 � O Optimum for population growth ptimum for population growth � 80 80 75 75 � Helpful to slow population growth Helpful to slow population growth � 60 60 � Generally stops population growth Generally stops population growth � 50 50 � Leads to eventual death of storage insects Leads to eventual death of storage insects � 40 � Winter storage (stops moisture migration) Winter storage (stops moisture migration) 40 � < 0 0 � Only way to achieve quick kill… Only way to achieve quick kill… � < °F °F

Insect Control in Stored Grain Insect Control in Stored Grain Meet SAM SAM : : Meet S anitation S anitation A eration A eration M onitoring M onitoring

Insect Control in Stored Grain Insect Control in Stored Grain S anitation S anitation – eliminate sources of infestation eliminate sources of infestation – A eration A eration – cool immediately to slow development cool immediately to slow development – M onitoring M onitoring – temperature & insect numbers temperature & insect numbers –

Controlled Aeration Controlled Aeration Using thermostatic controllers to Using thermostatic controllers to automate the aeration cycles automate the aeration cycles Objective: keep grain within 10 keep grain within 10 – – 15°F of 15°F of Objective: average ambient temperature average ambient temperature Three Cooling Cycles Three Cooling Cycles Summer: Cool grain immediately below 75°F Summer: Cool grain immediately below 75°F Fall: Cool below 60°F as soon as weather Fall: Cool below 60°F as soon as weather permits permits Late Fall: Cool to 40°F for winter storage Late Fall: Cool to 40°F for winter storage

Controlled Aeration Controlled Aeration � Simple aeration controllers are: Simple aeration controllers are: � – cheap (pay off cheap (pay off ≤ ≤ one year) one year) – – easy to use (thermostat + hour meter) easy to use (thermostat + hour meter) – – effective and efficient effective and efficient – – – and should be on every grain bin. and should be on every grain bin.

Controlled Aeration Controlled Aeration Using thermostatic controllers to Using thermostatic controllers to automate the aeration cycles automate the aeration cycles A simple controller: A simple controller: Thermostat Hour Meter Relay Fan

Grain Storage Cycle Grain Storage Cycle � Cool grain immediately below 75°F Cool grain immediately below 75°F � � Cool to 60°F as soon as feasible (weather) Cool to 60°F as soon as feasible (weather) � � Maintain the grain Maintain the grain � – monitor temperatures: monitor temperatures: aerate as needed – aerate as needed – monitor insects: monitor insects: aerate/ fum igate as – aerate/ fum igate as required required � Cool to 40°F for winter storage Cool to 40°F for winter storage � � Maintain the grain Maintain the grain – – seal fan opening seal fan opening �