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DANVA Tech-dage 11. juni 2013
Ultrasonic Water Well Cleaning
Regenering af boringer med highpower ultralyd
VandCenter Syd
Mads Clausen Institute, SDU
Funded by Vandsektorens Teknologiudviklingsfond (Project: 7300)
Robert Brehm, Mads Clausen Instituttet, Syddansk Universitet
Peer Locher, VandCenter Syd, Project manager
Johan Linderberg, VandCenter Syd, Hydrogeologist
Ultrasonic Water Well Cleaning
Regenering af boringer med highpower ultralyd
1. Project Introduction
2. Involved Technology and Equipment
3. Experimental Setups, Models and Results
4. Improvements
5. Current Progress and Summary
Project Introduction
Project partner:
Funded by:
Timeframe:
Budget:
VandCenter Syd, Mads Clausen Institute (SDU), InFlux
Vandsektorens Teknologiudviklingsfond
Jan. 2012 – Sept. 2013
~1.7 Million DKK
Projektpartnerne udvikler et ultralydsbaseret, miljøvenligt og energieffektivt
værktøj til rensning og regenerering af grundvandsboringer. Boringen bliver
dermed mere effektiv og regenerering foretages i én, tidsbesparende
arbejdsgang.
This work investigates the usage of high power ultrasonic push-pull transducer to rehabilitate
water wells in contrast to conservative well rehabilitation methods. We compare the effectiveness
of the ultrasonic cleaning method with state-of-art conventional cleaning methods such as brushes
and chemical acids.
In addition the task is to study the effectiveness and level of cleaning for different filter gravel
granularities and geology compounds around water wells.
Water Well Aging
Wells get clogged during time and the
productivity of the well declines.
Physical and chemical processes cause
the hydraulic conductivity of the wells filter
pipe and gravel pack to decline which
results in a higher draw-down at an specific
rate or as a loss in the discharge rate.
- Gravel coatings consists of oxidised iron
and manganese
- Particle clogging by silt and fine sands
- Precipitation hydroxides forming
incrustations between particles.
An aged Well
Before and After mechanical cleaning using brushing
Use known Ultrasonic Cleaning Technology
Push-Pull Transducer
Resonator rod induce longitudinal pulses in the resonator at the points of attachment.
Transducers inside each end cap produce cyclic positive and negative pressure waves
The positive pressure wave acts as a pushing force and the negative pressure wave
acts as a pulling force (hence "Push-pull").
The pushing and pulling action causes the rod to resonate at the frequency of operation.
As a result, near perfect, omni-directional radiation of sound waves is achieved.
Ultrasonic Cleaning Effects
Micromotion:
Micromotion at resonance causes rubbing of the filter
gravel stones at each other. Coatings will be rubbed
off if not completely hardened.
Oscillation:
The gravel stones will start volume oscillating and
coatings are broken off by spalling.
Fluidify thixotropics:
The ultrasonic energy is used to fluidify thixotropic
cements, cut and break molecular lattice of gels,
slime, colloidal substances
The test well setup
Determination of cleaning efficiency
Measurement of the time (flow rate) it takes for a fixed volume of water to flow through a fixed volume of gravel
sample. Different samples and a reference ”clean” sample have been tested. DARCY-test.
Water reservoir
Valve (slider)
Tube to be filled
with gravel
~400mm
Fine mesh
Ø ~50mm
Proof-of-Concept Experiments Results
Recent results in water well model
Dirty Gravel Sieved
2
67,62
64,1
66,43
68,18
67,47
68,91
65,97
65,09
66,5
69,35
67,91
68,09
70,75
59,94
Mean 67,1166667
66,70125
Std. 2,22489251 3,05282276
1
0,89
0,90
CLEAN
REFERENCE
50,6
51,81
55,19
48,66
50,32
51,19
52,72
50,19
51,335
1,966250965
Cleaned TOP
(15-20cm away)
53,28
45,03
58,57
58,81
54,28
55
50,6
56,59
54,02
4,540981643
Cleaned BOT
(15-20cm away)
53,97
47,16
46,6
40,87
53,47
54,28
44,25
43,19
47,97375
5,287394545
Cleaned TOP
(10cm away)
51,34
51,12
44,29
54,03
54,5
52,18
44,29
50,78
50,31625
3,951668499
Cleaned BOT
(10cm away)
48,71
55,15
57,69
52,28
56,35
44,65
55,09
54,06
50,996875
4,914188094
1,17
1,11
1,25
1,19
1,18
1.40
1.20
1.00
Flow rate in l/min
Flow l/min
3
Dirty Batch 1
Dirty Batch 2
0.80
Clean TOP 25cm
Clean Bottom 25cm
0.60
Clean Top 10cm
Claen BOT 10cm
0.40
0.20
0.00
CLEAN REF
Verification of results with real core samples from a polluted
well inside a tank.
(75cm core sample cleaned by the ultrasonic push-pull transducer)
400
350
Time in seconds
300
250
200
Clean
Dirty
150
100
50
0
0
1
2
3
Sample Number
4
Time in seconds for 1l to pass through fixed volume of gravel.
5
6
In-Situ testing and verification at a real well in Odense.
Quantitative verification through high range turbidity sensor +
Qualitative visual verification of cleaning effect using an underwater camera
Camera
Ultrasonic Probe
Inner well tube
Gravel pack
Turbidity and Video inspection results.
20
data 1
relative Turbidity inTuunits
15
10
5
0
-5
-10
80
90
100
110
Time in minutes
120
130
Kerneboring til dokumentation af tilklogning af boring
Grundvandets
strømningsretning
Indv. boring
Test boringer
Sonic Drill Core sampling
Kerne prøver fra V3e Testsite
Okkerforurenet grus i formationen begynder 7 m.u.vsp.
Mathematical modeling of sound propagation inside the well.
Filter tube barrierer (signal loss ~70%)
Measurement of sound propagation inside water well (tank model) using
Hydrophones:
… Compare to model … wave maxima/minima every:
2
1481 /
2 ∙ 250001/
0.029
RESULTATER INDTIL VIDERE
1. Push-Pull sonden er ikke så egnet som hidtil antaget.
2. Energitabet fra sonde til-vand-til PVCrør til gruskastning er
for stor > 75-90 %
3. Behov for at skabe kontakt mellem sonde og boringsrør
4. Derved minskes tabet betydeligt
5. En prototype er udviklet
6. Målinger er foretaget med betydeligt forbedret resultat.
7. En fuldt opbygget prototype er ved at blive bygget og skal
testes snarest.
Transducer
Kontakt flade (stempel)
Improvements for intensity loss compensation
Bevægelse af transducere mod foringsrør.
Improved Accoustic bridge –
Transducer in direct connection to filter
tube
Advantage: Reduction of losses (no loss of
intermediate layers between transducer and tube)
Stacking af enheder
• Planen er at placere en
række lag med
transducere monteret
med 120° graders
vinkel.
• Der skal minimum
være 6 stk. eller
multipler af 6.
• Dvs. 6, 12, 18 osv.
… Currently ongoing …
Consisting of:
-
Pump test, before and after treatment
-
Turbidity measurement of pumped water
-
Hydrophone intensity measurement in different distances
-
Camera inspection during treatment
Special thanks to:
For providing the most accurate in-situ “MultiSense TuX High-Range Turbidity
Sensor” for the In-Situ turbidity measurements.
For further information or discussions please contact:
Peer Locher, tlf.: 63 13 23 71, [email protected], mobil 40 80 84 62
VandCenter Syd as
Johan Linderberg tlf. 63 13 23 27, [email protected], mobil 40 80 84 72
Vandværksvej 7, 5000 Odense C
www.vandcenter.dk
Robert Brehm
MCI, Mads Clausen Instituttet, 6400 Sønderborg, tlf.: 65501612,
[email protected]
www.sdu.dk/mci
Or visit:
http://vtu-fonden.dk/projektzonen
Project: 7300
-> http://vtu-fonden.dk/projektzonen/projekter/2011/7300.aspx