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Fan impeller and protective grid have to be regu-
larly checked for deposits and cleaned.
Deposits on the protective grid restrict the air
flow and thus lead to blockage in the seed pipes.
Deposits on the fan impeller cause unbalance.
The bearing will thereby be overloaded and can
be damaged.
Fan direct drive
In direct drive the fan is driven by the tractor
hydraulics.
The tractor mounted control unit for fan speed
control must be equipped with a flow control valve.
Fan direct drive
The hydraulic pump must deliver sufficient oil to
prevent the fan speed dropping, even when the
tractor speed drops or other hydraulic functions
are activated.
The fan speed is adjusted via the oil
quantity on the flow control valve in the
tractor.
The leak oil return line must be pres-
sureless (max. 5 bar) connected to the
tractor!
Operation
Pneumatics Pronto AS
Depending on the equipment the pneumatic
system consists of a fan, one Venturi area per
metering unit and one or two distributors.
Machines equipped for solid fertiliser have an-
other distributor in the rear hopper.
Fan
The fans are directly hydraulically driven by the
tractor hydraulics or by a PTO-shaft driven pump.
The generated air flow conveys seed / fertiliser
from the Venturi area to the coulters.
The required air quantity depends on seed / ferti-
liser (type and weight), seed or fertiliser quantity,
working width and sowing speed.
A correct fan speed cannot be specified and
must therefore be determined by tests in the field.
The air flow must not be too strong, so that the
seed / fertiliser will not be blown out of the furrow.
It must, however, not be too low, so that no
seed or fertiliser deposits remain in the hoses
and cause blockage. Too weak an air flow may
also have a negative effect on the transverse
distribution.
The fan speed should therefore be set as high
as possible.
Fan setting, seed transportation and
seed placement must be checked on
all coulters when starting sowing, and
also at regular intervals when working
on large areas.
