28 July 1995

Sprayer means end to priming

SPRAY operators who enter a field and have to waste time "priming" booms to ensure each nozzle is delivering the correct concentration of chemical will be interested in the latest Knight Farm Machinery development, writes Andy Collings.

Still undecided on what to call the system, the company has settled on: "The Quick Start Recirculating System" – which is descriptive, if lacking in a degree of marketing panache.

However, that is not to malign what is clearly a significant sprayer development and one which must surely have a contribution to make to environmental care – and a reduction in wasted chemical.

Key to the system is the use of boom recirculation – not unique by any means until it is known the Knight method reverses the flow by sucking rather than pumping the liquid when the sprayer is switched off. This results in a negative pressure in the boom lines, avoiding any possibility of seepage from nozzles.

It will be recalled conventional recirculation systems rely on the nozzles check valves remaining closed under low pressure to avoid dribbles occurring. And a feature of the system is that flow control metering systems are unaffected by the recirculation.

Yet another advantage of the Knight system becomes apparent when spraying is finished. Clean water is sucked through the spray lines from the clean water tank with the washings being retained in the tank – avoiding the need to spray out in the field.

The recirculation system should be available for next season. &#42

Knights "Quick Start Recirculating System" means sprayer operators no longer have to waste time priming booms before starting work.