Back To Main Press Releases
The application stage of precision farming involves variable application of fertilizer and chemical inputs so that each section of the field receives the appropriate dose of chemical. This requirement inevitably means that large variations are sometimes required. The purpose of this document is to explain the importance of direct injection as an essential component of precision farming.
SPRAY DROPLET FORMATION WITH HYDRAULIC NOZZLES.
Conventional hydraulic nozzles produce an optimum droplet pattern over a narrow range of pressures and flows. If for example a particular field area required half rate chemical rather than full rate then the flow rate reduction through the nozzle would cause the pressure to drop from 4 bar pressure to 1 bar which is below the threshold at which many nozzles operate satisfactorily. Therefore although it is possible to control a standard nozzle output from zero to maximum flow, In practise this is only possible in the range of +/- 10%.
DIRECT INJECTION - CONSTANT PRESSURE SPRAYING.
The solution for this problem is to maintain pressure and thus spray quality by using the main carrier flow at a more or less constant pressure. With direct injection we are then free to use the active chemical ingredient at any rate between zero and maximum to provide the desired application. The Raven direct injection system can provide independent control for up to 5 different chemicals. The injection rate is automatically adjusted according to forward speed thus giving a constant rate of application per hectare. It is also possible to control the carrier flow to give either constant pressure or constant rate.
HIGH PRESSURE INJECTION - ESSENTIAL FOR PRECISION APPLICATIONS
The Raven Injection system has a high pressure pump which allows injection after the main spray pump thus keeping working parts free of chemical but more importantly allowing injection of chemical just prior to the boom thus ensuring the quickest possible response. This is essential when using a GPS unit to vary application rates across the field. Low pressure injection can't do this.