4/21/2010

    Fertilizer use exploded after WWII  Plants built during the war to supply nitrogen for bombs; after war supplied ammonia for fertilizer Most of ammonia applied in 1940’s was ammonium nitrate pellets, but this was highly explosive Research on anhydrous ammonia started in mid 1940’s 1943 researchers at Mississippi Agricultural Experiment Station developed a way of injecting anhydrous into soil

   At local coop in Grant county UAN - $280/ton  28-0-0  $0.50/lb of N Anhydrous Ammonia $390/ton  82-0-0  $0.23/lb of N

  Do a good job of applying consistent amounts over a field, but not to each knife.

Poor distribution of ammonia is more evident in strip-till

   Anhydrous ammonia is a liquid under pressure A small percentage of ammonia vaporizes when pressure drops Majority of mass in ammonia is in liquid while gaseous ammonia is a large part of the volume  Up to 90% of space inside metering valve can be gas, making uniform distribution difficult

  Traditional systems  Over-apply to compensate for rows with less ammonia    Application at an angle to planting rows Equal hose lengths between the manifold and knife Unused manifold ports should be plugged equally Upgrade to newer metering systems

  aNH3 Equaply System  Maintains constant pressure of ammonia distributed to knives   Allows for anhydrous ammonia to be distributed over a wide variation in tank pressure Flow control system is used to assure rate of application and to allow for variable rate application Liquimatic System  No need for heat exchanger   Works almost like a steam trap Can handle higher rates

  Nurse Tank  Requires a high flow globe valve at the nurse tank  For high rates, dual tanks are recommended Heat Exchanger  Cools anhydrous ammonia below its boiling point and condenses vapor into liquid  Pump increases pressure of liquid and lowers the boiling point

 Pump   Uses a Hypro centrifugal pump with a hydraulic motor  Avoids surges like in a piston pump Pump keeps anhydrous ammonia at a liquid until it is split evenly at the manifold

 Flow and Measurement Control  Signals from flow sensor go to a cab console which operates the servo valve   Can interface with AgLeader, Raven, and John Deere Greenstar II Also uses a gauge tree to monitor flow to individual rows

 Monitor and Gauge tree

 Manifolds and Orifices  From servo valve, anhydrous ammonia goes to one or more manifolds that are controlled by an electronic on/off valve  From these manifolds, EVA ammonia tubing runs to individual knives  Connecting lines also go to gauge tree

    Accurate control of anhydrous ammonia application Ability to achieve variable rates Decrease of streaking in fields Can be used in no-till situations

    Anhydrous Ammonia flows from tank to a Liquimatic tower Tower has a metal dam in it making incoming vapor and liquid move upward When pressure from vapor reaches a certain point, a solenoid opens a valve and lets off liquid This also keeps a head pressure on liquid ammonia, ensuring it remains a liquid

 Flow meter after the tower is metering only liquid which makes it much more accurate

  Eliminates the need for a heat exchanger Allows for higher rates  Can apply up to 80 gallons/minute  60 ft applicator can apply 250 lb/ac anhydrous at 12 mph