design

1. KURSUS ASAS REKABENTUK SISTEM
PAM PENGAIRAN PERTANIAN
24 – 26 FEBRUARI 2015
IPMI UTARA

2. ASAS REKABENTUK PAM
• Pengenalan Kepada Sistem Pengairan Pertanian
• Penentuan Kadar Alir ( Flow)
• Penentuan Kehilangan Turus (Head Loss)
• Pengiraan Sistem Curve
• Match System And Pump Curves
• Select Pump Curves
• Size Infrastructures
• Determine Electrical Systems Control
• Aksesori

3. WHAT IS IRRIGATION?
• Application of water to soil by providing it to crop
filled land.
– To assist in crop production.
– Sustain plant life.
– Protecting crops from frost.
• Goal: To make land fertile and lush.
• Focus : Profitability – energy optimization and
better use of water
resources.

4. FLOOD IRRIGATION
• Half of the water applied to the field actually
irrigates the crops and the other half is lost
through evaporation, runoff, transpiration,
weeds, and infiltration of uncultivated areas.
• The efficiency of flood irrigation is not very high.
• Important concerns :
– Distribution uniformity.
– Field flooding
– Environmental impact of crops.

5. FLOOD IRRIGATION
• Furrow Irrigation
• Water is directed or
pumped into a
number of furrows,
which are then
flooded.
• Gravity flow channel.
• Requires lot of water.
• Common irrigation
techniques in tropical
area.

6. MODERN PRESSURISED IRRIGATION
SPRINKEL IRRIGATION
 Artificial Rain
 Uniform application.
 Two common types:
 Fixed sprinkler
 Travelling sprinkler
DRIP IRRIGATION
 Water and nutrients are
applied directly to the
root zone.
 Eg: Hydrophonics
 Lot of maintenance –
clogging.

7. IRRIGATION PUMP
• CRUCIAL CRITERIA
– Availability of water
• Type of water
• Volume of water
– Crop’s need for water

8. Source of Water
• Common preception of water - Water was an
infinite resource.
• Water resources need to be managed.
• Surface water drawn from rivers, canals, lake
or reservoir.
• Different source of water different type of
pumps been used.

9. SOURCE OF WATER
Water availability on earth:
• 3% is fresh or 1% available for use
• 70% is held in the ice caps
• 30% is available as groundwater of from lakes
and streams.

10. GROUNDWATER
PROS:
• Most reliable water source on earth
• Correct management is vital
• Groundwater measurement are fairly complicated,
because its flow is hidden.
CONS:
• Supply limitations
• Pump wear
• Clogging
• Over pumping

11. SURFACE WATER
• 2nd most common source of fresh water.
• The most common source in Malaysia’s
Irrigation activity.
• Correct pump levelling / water storage.
• “Enemy” of pumps for surface water:
– Mud, silt, organism growth, woods, sand.

12. RAINWATER
• Water source for raining season.
• Pumping schedule will stop at this time.

13. PUMPS SELECTION
• CRUCIAL CRITERIA
– Typically been over-sized
– Power consumption low
– Maintaining system pressure
– Adding variable speed control
– Motor protection

14. • DEFINISI PAM

15. JENIS PAM
PUMPS DISPLACEMENTS
RECIPROCATING
PISTON,
PLUNGER
DIAPHRAGM
ROTARY
SINGLE ROTOR
MULTIPLE ROTOR
DYNAMICS
SPECIAL EFFECT
JET
GAS LIFT
HYDRAULIC RAM
ELECTROMAGNATIC
CENTRIFUGAL
AXIAL FLOW
MIXED FLOW,
RADIAL FLOW
PERIPHERAL

16. PD VS CENTRIFUGAL
Flow rate versus pressure
• By looking at the
performance chart, the
centrifugal has varying
flow depending on
pressure or head,
whereas the PD pump
has more or less
constant flow
regardless of pressure.

17. PD VS CENTRIFUGAL

18. PD VS CENTRIFUGAL
Flow rate versus viscosity
• The centrifugal pump
loses flow as the
viscosity goes up but
the PD pump’s flow
actually increases. This
is because the higher
viscosity liquids fill the
clearances of the pump
causing a higher
volumetric efficiency.

19. PD VS CENTRIFUGAL
Efficiency vs Viscosity
• Viscosity also plays an
important role in
mechanical efficiency.
Because the centrifugal
pump operates at
motor spefficiency goes
down as viscosity
increases due to
increased frictional
losses within the pump.

21. CENTRIFUGAL PUMP
• Pam yang paling
banyak digunakan
di JPS.
• 3 jenis yang biasa
digunakan Radial
Flow, Axial Flow
dan Mix Flow.

22. CENTRIFUGAL PUMP

23. • Penentuan Kadar Alir
• Pengiraan Kehilangan
Turus (Head Loss
Calculation)
Tapak
• Pengiraan Sistem
Curve
• Matching system and
pump curve
• Pemilihan Pam
Pam • Saiz Infrastruktur
• Sistem Kawalan
Elektrik
• Aksesori
Finallize

24. PROSES REKABENTUK SISTEM PAM
PENGAIRAN
1. Penentuan Kadar Alir
2. Pengiraan Kehilangan Turus (Head Loss
Calculation)
3. Pengiraan Sistem Curve

25. Sistem Curve
Range Curve
Head, Power Consumption, NPSH Curve

26. Adverse Hydraulic Phenomena
• Excessive pre-swirl
– Change flow conditions
– Change in pump
performance
– Bearing wear
– Cavitation across impeller
• Uneven velocity distribution

27. • Entrained air
– Minor air entrainment
will lead to a clear
reduction in pump
performance and loss
of efficiency; the
severity depends upon
the quantity of air
entrained and the
pump type.

28. • Vortices
– Unlike excessive pre-swirl, vortices
appear locally with higher intensity and
are a major hindrance to proper pump
operation, resulting in cavitation, uneven
load, noise and vibration. There are
several different types of vortices. The
most commonly known type is the free
surface vortex, which can have varying
degrees of intensity from weak surface
vortices to fully developed vortices with a
continuous air core that extends from the
surface into the pump. Less well known,
but just as common is the vortex that
originates under the surface from the
sump bottom, walls or between two
pumps, and extends to the pump inlet.
This type of vortex can achieve high
rotational speeds with high subpressures
and cavitations.