PDF file - Israel Trade Commission

Agriculture 2011
Figure 2: A very large inlet filter
of the Vardit dripper.
7 8
area and enables water to enter the dripper through one
of the many active inlets (Figure 2). The size of the active
inlet filter is very important for dripper block resistance.
Studies have shown that most of the drippers’ clogs are
found on the inlet filter and that the active area size has
a major impact on dripper clog resistance.
The Assif dripper is an anti -siphon PC dripper designed
mainly for SDI. The anti-siphon mechanism prevents
the suction of surrounding water and dirt into the
dripper, at the end of the irrigation cycle, when the dripline
is drained and vacuum pressure conditions develop
on some areas along the lateral. The Assif dripper is
produced with the Rootguard version for reliable root
protection in SDI.
Figure 1: The Inbar drippers
appear to be almost identical
from the outside.
Figure 3: Partial clogging of the
inlet filter of the Inbar dripper,
when using effluent water, still
enables the nominal dripper
flow-rate.
turbulent, high velocity flow pattern to prevent particles
from settling in the dripper.
Non-drain dripper: a dripper that keeps the lateral filled
with water between irrigation cycles, for immediate
watering from all drippers along the drip-line with each
irrigation cycle.
Anti-siphon dripper: a dripper that shuts down
simultaneously with the drop of pressure in the lateral
at the end of the irrigation cycle, to prevent air and water
suction through the dripper outlet and the penetration
of sand and soil into the dripper - mainly for SDI.
Rootguard dripper: a dripper that contains impregnated
chemicals which prevent root intrusion into the dripper
in SDI, eliminating the need for any other treatment for
many years.
The new Inbar dripper collection was developed by
Metzerplas to meet the challenges of the new generation
of drippers. The group includes three drippers, which
seem almost identical from the outside (Figure 1), but
are distinguished by unique designs to accomplish
special individual features.
The Vardit dripper is a small, flat PC dripper with a very
large inlet filter that covers most of the dripper surface
The Inbar dripper is an ND (Non-Drain) and AS flat PC
dripper that keeps the lateral filled with water between
the irrigation cycles. In a regular drip-line, the lateral is
not filled with water at all times and the first drippers
start to irrigate prior to the adjacent ones. In long
laterals, the time required for a complete filling and
for pressure to be built up can take more than several
minutes. Pulse irrigation, characterized by many short
irrigation cycles during the day, increases the difference
in the watering level of each dripper along the drip-line.
In a ND drip-line, all of the drippers along the lateral
start watering at the same time for better and uniform
water distribution.
The revision of the features of both the ND and the AS
drippers has included a slight reduction in the size of the
inlet filter of the Assif and Inbar models in comparison to
the Vardit dripper, but the active inlet filter has remained
quite large to ensure free water passage into the dripper,
for all water quality levels. Field trials conducted with
Inbar drippers, using secondary treated effluent water
without additional chemical treatment (chlorination or
acidification), have been studied during the past three
years. The results indicate that the drippers maintain
their nominal flow rate, but the inlet filter shows partial
clogging (Figure 3). The inlet filter is large enough and
contains several active holes, each of them capable of
supplying the entire dripper flow-rate, to ensure clog
resistance.
gsagi@zahav.net.il
27