Blower Capacity
Page
119
05/06
The most important figure to look at
here is the heaviest amount of material
being conveyed down the least number of
primary tubes. In this case:
95kg/ha in 2 primary hoses.
Maximum allowable Application Rates
By referring to the charts on pages
122 to 125 we can determine the maximum
amount of material that can be reliably
conveyed.
Four charts have been produced to
show the maximum rates of conveyance for
2, 3, 4 and 6 primary hose systems. It is
possible to convey more material with 4
primary hoses than 2. This occurs because
the 4 primary hose system simply has more
available space in the hose to convey more
material.
The charts also show that as the
planting width is reduced the allowable
application rate will increase. This is also
true for the ground speed. As the speed
reduces the allowable application rate will
increase. Some examples follow.
Example 3
A conventional seeding system using a
4 outlet meterbox is required to plant
65kg/ha of wheat and 110kg/ha of fertilizer
down all 4 primary tubes. The implement
width is 14 metres and the proposed
ground speed for seeding will be 11 km/h.
The total application rate in this case is:
65 + 110kg/ha = 175kg/ha
By going to the graph on page 124
headed
‘maximum application rate 4
primary hoses’ we can see that the
maximum amount of material the system
can handle at 11km/h and 14 metres width
is approximately 280kg/ha. Therefore,
there should be no problems in conveying
the total application rate of 175kg/ha.
A moderate fan speed would appear to
be all that was needed to suit the medium
application rate of 175kg/ha. Choose a fan
speed of 4100rpm (refer page 120).
Example 4
A deep banding system using a 4 outlet
meterbox has been set up to plant 65kg/ha of
barley down the 2 outside primary tubes and
95kg/ha of DAP fertilizer down the 2 middle
primary tubes. The implement width is 12
metres and the proposed ground speed for
seeding will be 10km/h.
In this case we use the fertilizer
application rate to determine the conveyance
capacity. By going to the graph on page 122
headed ‘maximum application rate 2 primary
hoses’ we can see that the maximum amount
of material the system can handle is
180kg/ha (worked example below the graph).
Therefore, there should be no problems in
conveying the 95kg/ha of fertilizer down the 2
middle tubes. Fan speed would again only
require a middle range speed of 4100rpm.
Flow Control Valve
The Gason Air Seeder is fitted with a
flow control valve located next to the blower
unit. By altering the setting it is possible to
change the speed of the blower (Fig. B2).
After altering the setting lock the lever into
position with the screw fitted to the handle.
For
Closed
Centre
Hydraulic
Systems
refer to page 114.
Fig. B2 Flow Control Valve.
