Greenhouses
from the outset as it involves both
ground slopes and greenhouse
gutter slopes. It requires a
meeting of minds between the
greenhouse designer, the land
leveller, who will cut-and-fill and
the irrigation designer.
The norms for the ground
slopes are as follows.
ZZ Parallel to the
dripperlines (gutters)
and crop row direction.
1,0% < slope < 2,0%
ZZ At right angle to the
dripperlines (parallel
to the gable side).
0,25% ≤ slope < 2,0%
Greenhouse design
The irrigation design needs
to fit in with the greenhouse
design: inside and outside, which
needs coordination between
the irrigation designer and the
greenhouse designer.
Buried pipes for instance cannot
be laid within 300 mm of concrete
foundations. Multiple dedicated
mainlines outside the greenhouse
need room to be laid, generally
300 mm between mainlines.
Climate control
Climate control design and
planning is undertaken by the
greenhouse designer but the
actual climate controller is often
selected and installed by the
irrigation designer.
XX Automation
and communication
This equipment shares an electric
supply with common wireways
and cable sleeves. There must
be a common surge and
lightning protection programme.
It is important that different
voltages are kept separate. For
instance, sensor cables (extra
low voltage) and particularly
communication cables should
not share wireways / sleeves with
230V / 400V (low voltage). It
must be decided whether to use
aerial or underground cables.
This
involves
coordination
between the irrigation designer,
greenhouse designer, electrical
supplier and the builder.
Irrigation equipment includes:
XX Irrigation, service water and
cooling systems.
XX Fertiliser equipment.
XX Automation
and communication
Non-irrigation
equipment includes:
XX Greenhouse motors –
fans, vents, curtains,
screens, pad pumps.
XX Heating.
XX Lighting – head control,
greenhouse, outside.
XX General supply
°C
m3/h
Heating
The heating layout must fit in
with the irrigation layout and
involves coordination between
the irrigation designer, the
greenhouse designer and the
heating contractor.
Roads
Irrigation pipes lie underneath
roads. It must be planned which
comes first, the pipe or the road?
If the road, then sleeves will be
necessary through which to lay
pipe. If the pipe, then that pipe
would need to be steel. The
same would apply to cables:
over or under roads? If under,
which comes first, the cable
sleeve or the road?
Electricity supply
Electrical power is supplied to
irrigation and non-irrigation
equipment.
An
integrated
electrical
supply
system
must be designed.
bar
l/s
fact
Precise monitoring of water
flows and leak detection
in irrigation networks
WATERFLUX 3070 –
technology driven by KROHNE
• Electromagnetic water meter with
integrated temperature and
pressure measurement
• Line pressure monitoring for leak
detection or pump efficiency control
SUMMARY
All parties and their equipment
crisscross each other in a
confined space. Communication
between the parties will not
happen spontaneously. A fulltime Project Manager is essential.
• Multiple power concept for any location
• Remote transmission of readings
and meter status as option
This paper is aimed at
emphasising the need for
thorough
planning
of
a
greenhouse irrigation system.
It
has
highlighted
from
experience, certain technical
aspects that have been pitfalls
through inadequate planning.
Not all aspects though have
been covered. A project manager
needs to think through each and
every aspect carefully for success
in the long run.
AUGUST/SEPTEMBER 2016
15
m/s
KROHNE South Africa
8 Bushbuck Close, Corporate Park South
Randjiespark, Midrand, Tel.: +27 113141391
Fax: +27 113141681, John Alexander,
[email protected], www.za.krohne.com