Jetting Race (AJR)
Built to NSW DPI recommended design principles as a
result of research work carried out at the Trangie Agricultural Research Centre
WHAT IS JETTING?
Jetting is the application of a liquid substance to the outer body of a sheep to
kill external parasites actually present on the sheep or as a residual treatment
to deter parasite infection. Blowfly strike is the main
target and the greatest threat to the life of a sheep. Once struck a sheep may
only live days if not detected and treated, suffering a painful,
slow death. Prevention is better than cure. The best way to apply the life
saving pesticide is with a weak mixture of water. Effective jetting
is only achieved by penetrating the wool on a sheep and wetting to skin level in
those areas on the body most likely to be affected by fly strike, i.e. the poll
(head), the shoulders, back, rump and crutch area and the pizzle area on male
AUTOMATIC JETTING RACE (AJR)
The AJR is a machine which when connected to a water based pressure source and
has sheep passing through it, applies the pesticide to the body of each sheep as
required by the above description. It is a quick and efficient way to treat
large numbers of sheep. There have been many different kinds of jetting races
built and used in the past all achieving various degrees of efficiency. Research
has discovered many inefficiencies in performance and effectiveness of some
JetEzy =NEW PRINCIPLES
Effective wetting is best achieved by arranging spray nozzles so that the target
areas of fleece are sprayed more than once. This is achieved by positioning
multiple nozzles in line with the sheep flow.
Good penetration is only achieved with a solid stream. Streams which break into
droplets are less effective. Fan, cone nozzles or small diameter solid stream
types under high pressure should not be used. Spray height is important. The
further the nozzles are away from the fleece, the more the stream will break up
and become less effective. The height of the spray bars in the JetEzy can be
quickly adjusted by a simple vertical slide, to suit the size of the sheep in
the mob. The closer the spray bars the more effective the application will
become. The lateral position of the top spray bars can also be adjusted.
JET FLOW ACTIVATION
As each sheep enters the machine it breaks an invisible beam created by a sensor
mounted in a track in the side wall. This instantly activates the water blast
through all the jets. When the sheep pass by the sensor the water blast is
instantly stopped. The sensor, which is magnetically secured in the track, can
be placed at any point along the track. This provides precise activation at the
optimum moment so the target area is hit as the sheep passes through.
Sufficient volume needs to be retained in the fleece so that some jetting fluid
runs around the body of the sheep at skin level. Less than optimum volumes will
only partially wet the sheep. Two to five litres may need to be retained by each
sheep depending on the product used, wool length, sheep size and breed.
Jetting, as with many other husbandry operations should not be a "race" against
time, speed of sheep through the JetEzy should allow enough time for the correct
volume of spray to be applied to each
sheep. Good lead-up and exit systems play an important role here. A dual race
system with an 8 foot non back lead-up race will normally supply a smooth flow
of sheep to the jetter. An exit race is beneficial for slowing sheep down after
they leave the machine and to create a “draw” for incoming sheep retaining a
smooth even flow. Correct adjustment of the internal guide rails to suit sheep
size is also important.
Large size, all non-corrosive fittings are used on the JetEzy. A large electric
valve activates the flow when opened as each sheep passes through. An air loaded
pressure cylinder, with pressure gauge fitted, is used to maximize spray
performance through dampening the intermittent operation, it also produces an
instant flow when required at each opening of the valve.
WASTE RETRIEVAL TANK
The JetEzy is mounted on a low flat open top tank base with a capacity of
approx. 200 litres. Any wasted spray which occurs as each sheep passes through
is captured in the tank and can be used again. The 40mm outlet is fitted with a
PUMP SIZE REQUIREMENT
The pump pressure is determined by the nozzles and the pipe pressure loss, the
flow rate is determined by the number and size of nozzles and the sheep speed
through the JetEzy. Up to five litres of jetting fluid may be needed to be
applied to each sheep if they are in 3/4 to full wool (see recommended
application rates of the chemical being used). The recommended flow and pressure
required is 6 litres per second at 550 kPa, this means an 8 HP twin impeller
centrifugal pump, however excellent results have been achieved with a normal 5-6
The JetEzy is more effective than most existing machines and is
capable of providing longer protection from fly strike which means fewer repeat
treatments, this results in savings in operator labour and mustering time. Very
importantly, fewer treatments also results in lower contamination residues in
the wool at shearing time.
Large solid stream spray nozzles operating at lower pressures and a fully
enclosed top reduce spray drift, which significantly reduces the risk to the
operators of pesticide exposure.
FEATURES AND SPECIFICATIONS
1. Two in-line top spray bars each with five large diameter solid stream brass
jets. The bars are adjustable vertically for
clearance above the sheep, horizontally length ways so that the the sheep is in
the correct position when the flow begins,
plus each bar can be rotated to achieve the correct stream entry angle into the
fleece along the back line.
2. Single bottom spray bar with three large brass solid stream jets with angle
adjustment. Can be turned off with a ball
valve if not required.
3. Extra large diameter plumbing and fittings, all non-corrosive to
provide maximum flow.
4. Air chamber with gauge, large quick acting electric valve.
5. All galvanized steel construction, sheeted sides and base tank.
6. Adjustable internal side guide rails for correct sheep alignment
with the jets.
7. Perforations for drainage in floor with non-slip metal slats.
6. Designed to fit on one pallet, weight 100 Kg. approx.
7. Delicate components totally enclosed for protection.
EXTRA REQUIREMENTS (can be supplied on request)
● A good lead-up and exit system
● A fully charged 12 volt battery
● Suitable centrifugal pump
● Minimum 40 mm suction and delivery hoses
● Chemical mixing tank