Micron Technology Turbofan - Manual (Page 16)

DRAFT
15
4.2.13 Filter
All hydraulic systems MUST be filtered. For sprayers using the tractor’s hydraulic sys-
tem, a return line filter with a 25 micron replaceable cartridge and a full-flow by-pass re-
lief valve should be fitted in the return line to the tractor.
A pressure side filter MUST also be fitted in order to protect the gear motors and shaft
seals. A 10 micron filter should be used located between the tractor remote hydraulic
coupling (supply) and the first component in the sprayhead hydraulic circuit.
Self-contained systems should preferably be fitted with a 125 micron suction strainer be-
tween the oil reservoir and the hydraulic pump. A 25 micron replaceable cartridge filter
with a full-flow by-pass relief valve must always be fitted in the return to the reservoir.
Ensure that the filters are of adequate size to maintain oil flow even when partially
blocked. The return filter should be fitted with a pressure gauge to monitor the condition
of the filter by checking the back-pressure.
A pressure side filter should also be fitted to self-contained systems. See Fig 6 .
4.3 Spray Liquid
The flow of spray liquid to each Turbofan Sprayhead must be regulated to give the
correct total output from the sprayer and consequently the required application rate on the
crop.
Chemical flow can be regulated by either a fixed or a variable restrictor unit in the
feedpipe to each sprayhead.
Fixed restrictors or variable restrictors are available from Micron Sprayers as optional
extras.
The MICRON fixed restrictor uses an orifice plate fitted in a housing which can be
installed into the inlet connection of the sprayhead (Page 25, Item No. 29 , Micron Part
No. 6197).
See Section 7 (’CALIBRATION AND ADJUSTMENT’) for full details of the fixed
restrictor calibration procedure.
Unlike hydraulic nozzles, Micron Turbofan Sprayheads do not require a high pressure to
operate. Droplet size is unaffected by system pressure. The pressure should, therefore,
be selected to give the correct liquid flow through the restrictor (see Calibration section).
If an existing sprayer is to be converted, the original spray pump can often be retained. If
this pump is a high pressure type or if it has excess capacity, it may be necessary to fit an
adjustable pressure regulator in the feed to the sprayheads. If a pressure regulator is
already fitted but cannot be adjusted to a sufficiently low pressure, it will be necessary to
fit a second low pressure regulator to the output of the main regulator. This allows the
first regulator to by-pass the majority of the surplus flow to the tank and provide a
stabilised input to the second regulator.