High Altitude Spraying Machine

A high altitude spraying machine, also called a high-range sprayer or tall-tree cannon sprayer, is an air-blast sprayer built to reach the crowns of tall trees: street trees, shelter belts, forest stands, poplar nurseries and tall orchard crops such as pecan, walnut and palms. A fan blows a narrow, fast jet of air through a cannon that can be turned and tilted, and nozzles at the cannon head release the spray into it. This page lists a truck-mounted unit of the 30 m class in six groups.

How it works

An ordinary orchard sprayer, such as the orchard air-blast sprayer, spreads a wide fan of air a few meters into the canopy beside it. To reach 25 to 30 m up, a tall-tree sprayer concentrates a double-intake centrifugal fan's output into one jet leaving the cannon at 60 to 80 m/s. The nozzle ring around the cannon head releases the liquid into the fastest air, which breaks it into fine droplets and carries them up.

The operator aims the jet by slewing the turret and tilting the cannon, from the truck cab or with a wireless remote, or lets the controller sweep a set sector while the truck drives slowly along the trees. A piston-diaphragm pump supplies the nozzles at a pressure the regulator holds steady, and returns part of its flow to keep the tank stirred.

Where it is used

Forestry services use these machines against defoliating insects such as the oak processionary moth, and cities use them on street and park trees. The same layout, fed with water instead of pesticide, is the dust suppression cannon used on construction and mining sites.

Spraying this high puts fine droplets far downwind, so work is limited to calm weather, often early morning or night, and treated areas are kept clear of people. The rinse tank lets the machine be cleaned out before it leaves the treated area.

How the list is organized

Quantities are for one skid unit with its own diesel engine, carried on a truck bed; the truck itself is not listed. Tractor-mounted and trailed versions of the same machine drive the fan from the tractor PTO instead of an engine. Values come from the 30 m class European machines listed in the sources. Lines marked optional are fitted on many machines but not all.

Sources

• Maschio Gaspardo: Futura Cannone
• Maschio Gaspardo: Mistblowers range leaflet
• Vicar (CABA Industrie): catalogue with 451 and 541 cannon units
• Dragone AZ2-W data sheet
• OTL Jarocin: ODW-1 tall-tree sprayer
• Environmental Sciences Europe: drift from a cannon sprayer in oak processionary moth control (2023)
• Clarke: Buffalo Turbine specification sheet