How Equaply® Works

Accurate control of mixed gas and liquid phases is difficult to achieve. Conventional application systems do an excellent job of applying consistent amounts of anhydrous ammonia over a field. But they don't provide equal flow to each injector knife. Heat exchangers cool the ammonia below its boiling point before entering a flow meter and control valve. With only liquid present, the valve can exert near perfect control. However, when the anhydrous goes through the control valve it loses pressure and boils, creating a mixture of liquid and gas. This mixture is difficult to be split evenly in a manifold. So distribution among the knives is random and variable.

Strip till farmers can see the effects of poor ammonia distribution. Strip till corn rows and anhydrous rows are in the same place. When distribution is unequal some rows get more vapor and less liquid. "Streaking" is then visible across the width of toolbar application. A plugged anhydrous line becomes very visible after the corn plants emerge. Conventional tillage farmers are less likely to see uneven distribution. They usually over-apply so even the rows with less ammonia have an adequate amount. Also, they often apply at a diagonal; application and planting rows don't coincide. However, in the Fall of 2009, ammonia loss from the wet summer caused diagonal streaks as waves of green and yellow.

Operation of the aNH3 Equaply® System
1. Anhydrous passes through a basket filter as it enters the Equaply® system from the nurse tank. A 30 mesh stainless steel screen retains foreign material as small as 1/32 inch. Magnetic material deposits on a magnet inside the basket.

2. Our Liquimatic™ tower vapor separator (U.S. Patent 7,096,802) accepts flow from the basket filter, flow containing both liquid and gas. The tower separates the gas by letting it escape through a solenoid valve at the top of the tower. A small head pressure of liquid anhydrous inside the tower keeps pressure under boiling as the liquid enters the pump.

3. A Hypro centrifugal pump boosts pressure of anhydrous ammonia far above its boiling point. The pump assures constant pressure as the liquid is manifolded to knives.

4. A flow control system assures that the application of ammonia is constant. Variable rate application becomes easy.

5. Impellicone manifolds are standard with the Equaply® system-- this, in spite of the fact that they are made by one of one our competitors. They are a backup if, for some reason, flow of 100% liquid can’t be maintained.

6. At the exits from the manifolds, orifices keep anhydrous ammonia as a liquid until it has been split equally among knives (openers).

7. Each knife line leaving the manifold is split to a pressure gauge to monitor pressure. When pressures at all knives are equal, there are equal ammonia flows. Gauges can detect plugged lines and plugged orifices.

NURSE TANK CONNECTION- Formerly, we made recommendations regarding connections from the tank to the Equaply® system, those recommendations have become requirements. For high flow rates, the use of dual tanks and dual lines is necessary, particularly during cold weather. To maximize flow rates we recommend that you acquire tanks dedicated to your use. See our section on tanks for other details. Unlike Exactrix, our system doesn't need bottom outlet tanks.

VAPOR SEPARATOR- The one and only reason for heat exchangers with ammonia systems is to cool the anhydrous below its boiling point. In systems without pumps, vapor makes most flow meters inaccurate. Most pumped systems such as Equaply® vapor lock when a gas phase is present. Once pressure has been increased by the pump, the anhydrous is much below its boiling point. A hydrastat protects against over pressurization by solar heating of a standing, charged system.

PUMP- The pump assembly is arguably the most important part of our system. We use a Hypro centrifugal pump because it does not have surges like piston pumps. A hydraulic motor drives our pump. A solenoid operated hydraulic valve turns the pump motor on and off for each row.

Perhaps the most important reason for a pump is equal distribution. The pump keeps anhydrous as a liquid until it can be split at manifolds. To understand what happens with a mixed liquid/gas stream it helps to have transparent pipes. The Red Ball rotameters in our prototypes were those clear pipes. During startups and when there were malfunctions one could see the vapor as it went through the rotameters. When vapor first appeared in the system it would exit in the first rotameter in a bank of four. Increasing amounts of vapor then reached subsequent rotameters. Vapor takes the easiest path. For example, if there is a circular manifold on a toolbar which tilts down to the left on a hillside, vapor will tend to go out of hose barbs which are up and to the right, liquid going down to the left.

For custom applicators, the most important reason for a pump is the ability to apply at full rate when it's cold. Conventional systems often slow down during late Fall and early Spring.

FLOW MEASUREMENT AND CONTROL- Equaply® units have as standard, a Hiniker flow sensor and KZCO servo valve. Signals from the flow sensor go to a controller which then operates the servo valve. With our system the flow sensor has maximum accuracy because it sees only liquid. Equaply® units can interface to AgLeader Insight and John Deere Greenstar.

MANIFOLDS & ORIFICES- After the servo valve, we split flow at one or more manifolds. Each manifold is controlled by an electrically operated valve. Electric valves allow swath control, turning off one or more sections.

The range of rates possible with a given set of orifices is not great as we would like. This is particularly true with large seasonal temperature differences. Nurse tank pressure can easily range from 50 psig to 150 psig. Fortunately the TeeJet® orifices in the Equaply® system are quickly changed. If large rate variations are necessary as with custom application, we can widen the range using Impellione manifolds.

Side dress applications typically skip a row; a 16 row toolbar will have 15 knives. In that instance, we can supply orifices for the two end rows that have 0.5, 1.5 or 2 times the rate of interior rows.

FLOW VERIFICATION- The Equaply® system uses a pressure gauge per row to verify row to row equality of flow. When upstream pressure and downstream pressures are the same with orifices of equal size, flows are the same. Pressure gages connect downstream from the knife orifices. They are mounted on a gauge tree or panel between the tractor cab and the toolbar.

One can tell at a glance if a knife is plugged (high pressure) or an orifice is plugged (low pressure).