7 July 1995

New mist blower stops that drift

MIST blowers operating in orchards are not generally deemed to be the most environmentally acceptable way of applying pesticide. Chemical blown in the general direction of its target, with a significant percentage left to drift into the atmosphere, is clearly not a satisfactory situation by modern standards.

But now Tecnoma believes it has the answer in the form of the Turbocoll. Designed to be attached to a mist blower unit – in place of the conventional distribution system – it comprises a moulded plastic unit measuring 1.5m tall by about 25cm square. Air piped into this manifold accumulates in a bank of plenum chambers from which pressurised air is forced out through a series of pipes.

These pipes direct air into larger cone-shaped holes moulded into the manifold to create a venturi effect – drawing more air in. Air leaving the fan at typically 0.22cu m/sec results in an output from the venturi of 2cu m/second. Nozzles positioned between each pair of venturi inject chemical into the exiting air stream.

The result is a high volume of air, moving at a relatively slow speed, which is able to cover a greater area of vegetation with little wasted chemical or threat to the environment.

But there is more. The units can be positioned closer to trees and, for tall orchards, two or three of them can be stacked vertically to ensure complete cover – a mist blower of the capacity normally used in orchards is claimed to be capable of providing sufficient air volume to serve up to six Turbocoll units. &#42

Orchard spraying with Tecnoma.