performance evaluation of technos cleaning balls in rdc msf pilot

PERFORMANCE EVALUATION OF TECHNOS CLEANING
BALLS IN RDC MSF PILOT, AL-JUBAIL PHASE II,
AND JEDDAH PHASE III PLANTS 1
Ghulam M. Mustafa Osman Ahmed Hamed, Khalid Ba-Mardouf
and Hamed Al-Washmi
Saline Water Conversion Corporation
P.O.Box 8328, Al-Jubail -31951, Saudi Arabia
Tel: + 966-3-343 0012, Fax: + 966-3-343 1615
Email: rdc@swcc.gov.sa
Abdulsalam Al-Mobayed and Anwar Ahsan
Operations Dept., SWCC, Al-Jubail Plants
Nabil Nada and Mofarrah Al-Hodaibi
Engineering Dept., SWCC, Jeddah Plants
&
Bob Smith
PWE Ind. Ltd
SUMMARY
On-line tube cleaning by circulating sponge balls along with the use of
antiscalant is proved to be the most effective and economical means to avoid
fouling of internal surfaces of tubes in MSF distillers. This leads to reduced cost
of additives where lower dose rate could be sufficient. At an optimum sponge
ball cleaning in additive dosed MSF plant, the tube fouling can be maintained
as low as to achieve up to 40% of the mean energy saving. There are many
manufacturers of sponge cleaning balls such as Taprogge, Technos, Water
Science of America (WSA), Remington and Schmitz. In this work, the
performance of Technos balls has been evaluated in MSF distillers of Al-Jubail
and Jeddah desalination plants. Saline Water Conversion Corporation (SWCC)
and Power, Water & Energy (PWE) Industries Ltd., U.K. (the agent of Technos
Company, France) had come to an agreement to test the performance of
Technos balls and find out its suitability to use in SWCC MSF plants.
Preliminary testing of the balls was carried out for three weeks at 110 o C and 2
ppm dose rate of DSB(M) in MSF pilot plant mainly to check the temperature
tolerance and the effectiveness of the balls. Following the successful pilot plant
1 Issued as Technical Report No. TR-3808/EVP 95010 in December 2001
1

testing, Technos balls were tested in Jeddah III Unit 9 for 4 weeks at a TBT of
107°C and in Al-Jubail II Unit 16 for 6 weeks at a TBT of 98°C. Heat transfer
coefficients, fouling factors, plant performances and balls physical integrity
were monitored during the tests. The reduction in size of the balls due to
normal wear and loss of balls in the system during test period was found low
and within acceptable limits. The distiller performance and the inspection of the
balls during the tests at Jeddah and Al-Jubail plants showed that Technos balls
were effective and suitable for use in MSF distillers. It was therefore,
recommended to place the product on approved bidders’ list for Al-Jubail
Phase II and Jeddah Phase III Plants. Due to successful test of the Technos
balls, it is also recommended to use and evaluate long-term performance of
Technos balls in other SWCC plants.
1. INTRODUCTION
Cleanliness of water side tube surfaces is a significant factor affecting the heat transfer
capacity of seawater/brine cooled condensers in MSF distillation plants. Substances,
which adhere to the heat transfer surface, decrease tube cleanliness and impede transfer
of heat. These include precipitation fouling or scaling, biological fouling and particulate
fouling. Though the formation of scale, which is the main source of fouling in MSF
distillers, is combated and controlled by threshold treatment using antiscalant, its
complete prevention is impracticable. Sludge or distorted scale is also formed as a
result of threshold treatment and gets deposited on tube metallic surfaces thus creates
resistance to heat transfer. If not removed early after formation, these soft deposits
could convert into solid scale. Sludge can be easily removed by employing on-line
cleaning of the tubes. The combined use of antiscalant and on-line tube cleaning has
proved to be the most effective and economical means to avoid fouling of internal
surfaces of tubes. This leads to reduced cost of additives where lower dose rate could
suffice. The most effective on-line tube cleaning system that is currently in use in MSF
desalination plants is the sponge rubber ball circulation system. At an optimum sponge
ball cleaning in additive dosed MSF plant, the tube fouling can be maintained as low as
0.04 m 2 K/kW resulting in over 40% of the mean energy saving [1].
2

There are many manufacturers of sponge cleaning balls such as Taprogge, Technos,
Water Science of America (WSA), Remington and Schimitz. They produce many types
like polishing, granulate, high temperature and corundum ring or total coated sponge
balls. Technos has developed a technique to blend the balls with the special materials
that were previously used as coating on abrasive balls. The grain size of the abrasive
material is small enough to avoid the risk of scratching the tube metal surface, which
could trigger erosion-corrosion phenomena. The technique is claimed to provide a
major advantage over ball coating technique since the desired abrasive effectiveness
remains unchanged while the balls are being used [2].
The scale/sludge removal ability of sponge rubber balls depends on many factors such
as size, number, hardness, surface texture and age of the balls, the frequency and
duration of treatment, and nature of metallic surface. Based on the operating
experience, the average ball life in Al-Jubail Phase II Plant is 5-6 weeks with 8 cycles
of ball circulation per shift while in Jeddah plant, it is 4 weeks with 6 cycles per shift.
Al-Sofi et al. reported from operational experiences that the number of balls, which can
be fed to the system, could be as high as 60% of the number of tubes. He suggested that
30% or even less would be adequate, yet much lower percentages be insufficient to
reach all the tubes while a higher percentage would lead to tube blockage, crowding at
strainer and accelerated wear at tube mouth [3]. The frequency and cycles of ball
cleaning and ball to tube ratio used in SWCC MSF plants are reported by Dr. Hamed
O.A. el al. [4] and are given in Annexure 1.
In this project, for the first time Technos balls were evaluated at Research and
Development Center (RDC) of SWCC by conducting test run at MSF pilot plant.
Performance evaluation tests of Technos balls were further conducted in Jeddah III and
Al-Jubail II commercial plants. Preliminary evaluation test of Technos balls in MSF
pilot plant was conducted at a TBT of 110 o C and DSB(M) dose rate of 2 ppm over a
test period of three weeks. After the successful test at pilot plant, balls were evaluated
in Jeddah III Plant (Unit 9) at a TBT of 107°C and in Al-Jubail II Plant (Unit 16) at
TBT of 98°C. Physical integrity of the balls such as mechanical damage, shrinkage,
surface wear, deformation or loss of texture were monitored closely during the tests in
both Jeddah and Al-Jubail plants. The effectiveness of balls in removing soft scale and
sludge was also checked by calculating heat transfer coefficients and fouling factors.
3

Visual inspections of heat transfer surfaces were also conducted after the tests. It was
concluded that Technos balls had behaved satisfactorily and could be used in
commercial MSF plants.
2. OBJECTIVE
To evaluate the performance of the Technos cleaning balls in controlling scale
deposition in Al-Jubail phase II and Jeddah phase III desalination plants.
3. EXPERIMENTAL METHODOLOGY
3.1 Test Locations
Tests were conducted in MSF pilot, Jeddah III and Al-Jubail II plants to study the
performance of Technos balls. Brief description of the test plants is stated below.
3.1.1 RDC Pilot Plant
A 20 ton/day MSF pilot plant at RDC, Al-Jubail was used to give sufficient indication
of the performance of Technos balls. The pilot MSF unit consists of 4 stages in the heat
recovery section and 2 stages in the heat rejection section. It has all important features
of a fully established MSF commercial plant. Make-up seawater can be given additive
and/or acid treatment inclusive of external deaerator and decarbonator. There is also a
provision for acid cleaning of heat transfer tubes.
3.1.2 Jeddah Plant Phase III
Jeddah Phase III desalination and power plant is dual purpose plant designed to produce
daily a total of 88,000 m 3 of potable water ( by four distillers) and 250 MW of electric
power. The four MSF evaporators are of cross tube configuration and designed for
maximum top brine temperature of 107 o C. Each MSF desalination distiller has 14 heat
recovery stages and 2 heat rejection stages. A separate deaerator is available to each
unit. An on-line sponge ball cleaning system cleans the brine heater and heat recovery
tubes. Jeddah III brine heater has a double pass tube design compared to the single pass
in all other SWCC commercial plants.
4

3.1.3 Al-Jubail Plant Phase II
Al-Jubail Phase II desalination and power plants are also dual purpose plants designed
to produce daily 960,000 m 3 of potable water and 1300 MW of electric power. The
MSF distillers are having cross tube configuration and maximum top brine temperature
of 112.8 o C. The desalination unit where the test was carried out has 19 heat recovery
stages and 3 heat rejection stages. Deaeration is carried out in a separate deaerator
available with each unit. A sponge ball cleaning system is available for on-line cleaning
of brine heater and heat recovery tubes.
3.2 Test Materials
Sponge balls were supplied by PWE Industries Ltd., while other chemicals required in
the operation of plants such as antiscalant, antifoam and sodium sulfite were provided
by SWCC. The specifications of Technos balls are as follows:
Type of sponge balls : High Temperature,
Standard
RDC Pilot Plant Jeddah III Plant Al-Jubail II Plant
High Temperature,
Standard
High Temperature,
Standard
Hardness : Medium/Hard Medium/Hard Medium/Hard
Ball diameter : 15 mm 29 mm 42 mm
Temperature tolerance : 140 o C 140 o C 140 o C
No. of balls required : 100 8000 2100
3.3 Experimental Conditions
The operating conditions of pilot, Jeddah III and Al-Jubail II plants are given in Table 1.
3.4 Performance Evaluation Criteria
Following are the criteria for ball assessment.
3.4.1 Ball Physical Integrity
A fixed quantity of balls was charged in the evaporator. The balls were inspected daily
for the first 3 days and thereafter twice a week to check the following factors
responsible for ineffectiveness of the balls.
5

3.4.1.1 Mechanical Damage
Collision of balls with the flow path surfaces such as ball strainer, tube bends and ends,
water box walls and tube sheet are the most important factors responsible for ball
splitting or damage. The repeated compression of the balls as they enter the tubes also
leads to mechanical damage by erosion and peeling.
3.4.1.2 Shrinking
Shrinking which makes ball ineffective, is mainly attributed to the ball material and its
temperature tolerance. Ball shrinking can be measured by its size and weight.
3.4.1.3 Surface Wear
Ball wear which occurs by abrasion due to tube roughness and also by the sludge and
scale deposits in the tubes is a common phenomenon resulting in loss of ball
effectiveness. The phenomenon is related to the ball material and tube surface
conditions. Any uneven or accelerated wear of the balls was carefully examined during
the test runs. Perforated screens were used to estimate reduction in size of balls.
3.4.1.4 Deformation
Any deformation in the shape of the balls (e.g., shape change to cylindrical) results in
uneven tube cleaning. The deformation is mainly related to the temperature and
pressure tolerance of the balls’ materials. Cylindrical shape of the balls may result due
to deformation or due to constant wear of the balls in one direction. The wear and
deformation can be differentiated by the length and weight of the cylindrical balls.
3.4.1.5 Loss of Texture
Loss of texture is a major deficiency of balls that restricts the ability of balls to regain
their shape and size. It also results in sticky balls. Ball material should be good enough
to withstand high temperature and prolonged contact with seawater.
3.4.2 Thermal Performance
The heat transfer coefficient and fouling factor data which relate directly to the increase
of heat transfer resistance by scaling are plotted with time to evaluate the effectiveness
of the sponge balls in keeping the heat transfer surfaces clean. Chemical dose rate and
6

all cleaning frequency were kept same as in normal operation and test data were
recorded.
It is preferred to inspect visually the tubes and water-boxes of brine heater and high
temperature stages before and after the test to check the extent of scale and sludge
deposition. It provides information about the effective distribution or sinking rate of the
balls. However, the inspection of the commercial distillers is bound to the maintenance
schedule and high demand of water production.
3.4.3 Chemical Analyses
Chemical analyses of different brine streams were performed daily to monitor the
constituents responsible for steady operation of the plants. The analyses of copper
content in the brine recycle and brine blowdown streams were also done to find out the
extent of tube metal losses due to ball cleaning.
4. RESULTS AND DISCUSSION
During the tests of Technos balls in MSF pilot, Jeddah III and Al-Jubail II commercial
plants, operations including ball performance were monitored closely.
4.1 MSF Pilot Plant
Prior to the tests on commercial plants, a test on the RDC pilot plant was carried out to
make a preliminary assessment about the temperature tolerance and effectiveness of the
Technos balls. Balls were tested at 110 o C for one-week duration and the performance
was compared with that of the balls presently under use in the plant.
4.1.1 Ball Physical Integrity
Technos balls were checked for any mechanical damage, shrinkage, surface wear,
deformation or loss of texture periodically during execution of the test. Balls were not
found to undergo any sort of deformation, texture failure or any type of mechanical
damage during the test. The used balls were not found softer than the new ones. The
diameter of used balls was also around 14.5 mm. A little decrease in size (i.e. ∼0.5 mm)
was attributed to the shrinkage and uniform wear.
7

4.1.2 Thermal Performance
Overall heat transfer coefficients (OHTC) and fouling factors are calculated and plotted
with time to evaluate the effectiveness of sponge balls in keeping heat transfer surfaces
clean as shown in Figures 1. OHTC of brine heater tubes during test period fluctuated
between 4 to 4.8 kW/m 2 K, while fouling factors varied between 0.01 to 0.06 m 2 K/kW.
These values are found to be acceptable and quite matching with those normally
encountered during earlier operations (using other type of balls).
Tubes, tube sheets and water boxes of brine heater were inspected visually before and
after the test. In pre-test inspection after cleaning by acid operation, the brine heater
tubes and tube sheets were found clean. Post-test inspection revealed that there was
some soft scale (sludge) deposits on tube sheets. However, tubes were mostly free from
scale. Deposition of sludge on tube sheet can be attributed to high sludging
characteristic of DSB(M) at a dose rate of 2 ppm.
4.1.3 Chemical Analysis
The results of the chemical analysis, which included the copper contents, and alkalinity
of various brine streams in MSF pilot plant, were found within acceptable limits.
4.2 Jeddah III Commercial Plant
Test was carried out in unit 9 of Jeddah III Plant for duration of 4 weeks. Prior to the
test run, the distiller was cleaned by continuous acid operation for duration of two
weeks. The minutes of the meeting conducted before and after the tests are given in
Annexure 1.
4.2.1 Ball Physical Integrity
Physical integrity of Technos balls during a test period of four weeks was closely
examined and their conditions are reported in Table 2. Balls were not found to have
undergone any breakage, shrinkage or loss of texture. However, their roundness were
lost primarily due to wear which was found to be quite uneven. The extent of wear
causing deformation of Technos balls was found to be within acceptable limits of a
normal ball cleaning phenomenon. Figure 2 shows the deformed used balls and unused
balls. Used balls are deformed in cylindrical shape. It is primarily due to the fact that
8

alls once received certain wear in a particular orientation, keep themselves along the
same axis (due to less resistance) every time they go through a tube.
The consumption of the balls with time was also investigated and found that the rate of
balls replacement due to wear and tear was within acceptable limits. Balls started
becoming under-sized after 15 days of operation and on completion of 30 days of
operation, 1461 balls out of the total charge of 1600 were found under-sized. The ball
lifetime, however, depends mainly on distiller size, its configuration and frequency of
ball cleaning for a particular ball type. The number of balls rejected due to under-size in
each inspection is shown in Figure 3, while cumulative counts of balls damaged and
lost with time are plotted in Figure 4.
4.2.2 Thermal Performance
The plant performance and the brine heater fouling were examined during the test
period. The plant was unstable during the period of 50 to 150 hours of the test. Figure 5
shows the performance of the distiller during the test period including the trends of
fouling factor and heat transfer coefficient in brine heater. Fouling factor fluctuated in
the range of 0.1 to 0.32 m 2 K/kW but most of the time remained within 0.2 m 2 K/kW,
which is lower than the design service-fouling factor of 0.325 m 2 K/kW indicating the
effectiveness of ball cleaning system. Steady trend of fouling factor indicates positive
performance of Technos balls.
Trends of gain output ratio (GOR) and performance ratio (PR) during the test period
revealed that plant performance was constant and thus Technos balls were effective in
maintaining the heat transfer surfaces free from any additional scale deposition.
4.2.3 Chemical Analysis
Chemical analyses of various brine streams in distiller # 9 were carried out daily for
pH, M-alkalinity and chloride contents. These values were found within acceptable
limits. Loss of total alkalinity (LTA) and concentration ratio were calculated in streams
of brine recycle and brine blowdown. Figure 6 shows LTA, M-alkalinity, concentration
ratio and copper content of brine blowdown. Cu contents in the stream of brine
blowdown before and during ball cleaning were found fluctuating between 7 and 23
ppb, which is within normal limit of the Cu content found during normal operation.
9

4.3 Al-Jubail II Commercial Plant
First batch of Technos balls were tested in Units #8 & #15 of Al-Jubail II plant. The
tests failed due to low-ball recovery (from the system) and abnormal deformation (hard
material projection) of the balls. For the first time, the company had produced the balls
of 42 mm size and the deformation was due to the manufacturing defect. The matter
was conveyed to the manufacturer who sent a new batch of modified Technos balls for
further tests in Al-Jubail Unit #16. The test was successful and new Technos balls were
proved to be suitable for use in Al-Jubail desalination plant.
4.3.1 Balls Physical Integrity
During test in Unit # 16 of Al-Jubail II desalination plant, visual inspection of Technos
balls were carried out daily for any mechanical damage, shrinkage, surface wear,
deformation or loss of texture. The number of balls fed, damaged and lost in the system
during each inspection are presented in Table 3. During test period, balls were not
found to undergo any sort of deformation, shrinkage, texture failure or mechanical
damage. The roundness of balls was also maintained. The wear causing deformation of
balls was found negligible even after six weeks of test duration. The consumption of
balls was only due to their loss in the system, which is plotted in Figure 7.
The rate of reduction in size of the balls due to normal wear during test period was very
low and much below the acceptable limit of normal ball wear during ball cleaning
process (Figure 8). It shows the satisfactory performance of the Technos balls. During
more than 6 weeks of test duration, the average ball size was around 41 mm, which is
much above the minimum acceptable limit of 39 mm (recommended size for ball
replacement). No ball was rejected because of undersize during the test period.
4.3.2 Thermal Performance
The plant performance was monitored closely during the test period. Figure 9 shows the
variation of fouling factor and heat transfer coefficient in brine heater and also the trend
of flash range, water production and plant performance. Fouling factor fluctuated in the
range of 0.1 to 0.2 m 2 K/kW while HTC varied in the range of 2.6 to 3.4 kW/m 2 K,
which is higher than the design HTC of 2.26 kW/m 2 K indicating the effectiveness of
10

all cleaning system. The high fluctuation in fouling factor is due to instability of
operating parameters particularly flash range.
Performance ratio (PR) and gain output ratio (GOR) were calculated and they were
found steady. Figure 9 shows the trends of PR and GOR during the test period. GOR
varied from 7.6 to 8.2, which revealed that the plant performance was almost uniform
and thus Technos balls were effective in maintaining the heat transfer surfaces free
from any additional scale deposition.
4.3.3 Chemical Analysis
Chemical analyses of various brine streams in distiller # 16 were carried out daily for
pH, M-alkalinity and chloride and found within acceptable limits. Cu content in brine
blowdown stream during test period was also analyzed and found within the range of
Cu content during normal operation. Figure 10 shows loss of total alkalinity and
concentration ratio in streams of brine recycle.
5. CONCLUSIONS
Based on the above, the following conclusions are drawn:
(a)
(b)
(c)
(d)
No significant mechanical damage, shrinkage, abnormal deformation or loss of
texture was found in Technos balls during tests at pilot, Jeddah III and Al-Jubail
II plants.
Decrease in balls size or loss of their roundness during these tests was found
within acceptable limit, typically experienced in normal operation.
The consumption of the balls with time or the rate of balls replacement due to ball
undersize or deformation was found low and within acceptable limit.
Technos ball cleaning was found effective in controlling scale deposition in tubes
during tests conducted in MSF pilot plant of RDC and SWCC MSF distillers of
Al-Jubail II and Jeddah III plants.
11

6. RECOMMENDATIONS
(a) In view of the satisfactory performance of Technos balls in controlling scale
deposition in heat transfer tubes and maintaining plant performance during four
weeks of operation in Jeddah III plant at a TBT of 107 o C and six weeks in Al-
Jubail II plant at TBT of 98 o C, it is recommended to place the product on
approved bidders list for Al-Jubail Phase II and Jeddah Phase III plants.
(b) Due to successful tests and excellent performance of the Technos balls in the
above plants, it is recommended to use and evaluate Technos balls in other SWCC
plants.
12

Table 1. Operating Conditions for Trial Tests of Technos Cleaning Balls
Test location
Minimum
Duration
TBT
Conc. Ratio
(BR)
Type of
Antiscalant
Dose Rate of
Antiscalant
Sponge Balls Ball
Cleaning
Frequency
No. of
Balls/Charge
Test #1 :
3 Weeks
110 o C 1.4 DSB (M) 2 ppm Technos 6 cycles/
5
RDC MSF Pilot
Plant
(Nov. 2 to
Nov. 23, 1998)
8 hours
Test #2 :
4 Weeks
107 ∼1.4 DSB (M) 3 ppm Technos 6 cycles/
1600
Jeddah III plant,
(Unit 9)
(Feb.22 to
Mar. 23, 1999)
8 hours
Test #3:
6 Weeks
98 1.4 Belgard
1 ppm Technos 8 cycles/
500
Al-Jubail II Plant,
(Unit 16)
(Sept.1 to
Oct.14, 2001)
EV 2030
8 hours
13

Table 2. Technos Balls Inspection Report for Jeddah III Plant (Unit 9)
Balls Type : Technos
Starting Date : 22.2.99, 10:00 hr
S. Total
No. Inspection balls Charged
Date &Time
No. of Balls Recovered
Good
Damaged
No. of Balls Lost
in the System
No. of New
Balls Used
Type of Damage of Balls
Break Shrink Wear Deform
Cum. Cum. Cum. Remarks
1. 22.2.99, 10:00 1600 - - - - - - -
2. 23.2.99, 09:20 1591 1591 - - 9 9 - -
3. 24.2.99, 09:00 1590 1590 - - 1 10 - -
4. 27.2.99, 10:00 1580 1580 - - 10 20 - -
5. 28.2.99, 10:00 1563 1563 - - 17 37 - -
6. 1.3.99, 14:00 1630 1530 - - 33 70 100 100
7. 3.3.99, 08:30 1630 1630 - - 0 70 - 100
8. 6.3.99, 08:30 1620 1620 - - 10 80 - 100
9. 8.3.99, 08:30 1590 1590 - - 30 110 - 100 √ √
10. 10.3.99, 08:30 1553 1153 400 400 37 147 400 500 √ √
11. 13.3.99, 09:30 1590 1090 500 900 -37 110 500 1000 √ √
12. 15.3.99, 09:30 1590 1390 200 1100 - 110 200 1200 √ √
13. 17.3.99, 09:00 1590 1290 300 1400 - 110 300 1500 √ √
14. 21.3.99, 09:00 - 1530 60 1460 - 110 - 1560
Texture
14

Table 3. Technos Balls Inspection Report for Al-Jubail II Plant (Unit 16)
Balls Type : Technos
Starting Date : 01.09.2001, 10:00 hr
S. Total
No. Inspection Balls Charged
Date &Time
No. of Balls Recovered
Type of Damage of Balls
No. of Balls Lost No. of New
in the System Balls Used
Good Damaged
Break Shrink Wear Deform Texture
Cum. Cum. Cum. Remarks
1. 1-Sep-01 500 - - 0 0 0 - -
2. 3-Sep-01 374 374 - 0 126 126 - -
3. 5-Sep-01 344 344 - 0 30 156 - -
4. 7-Sep-01 450 367 2 2 -25 131 83 83 √
5. 10-Sep-01 365 365 - 2 85 216 - 83
6. 15-Sep-01 404 404 - 2 -39 177 - 83
7. 23-Sep-01 435 435 - 2 -31 146 - 83
8. 30-Sep-01 459 459 - 2 -24 122 - 83
9. 7-Oct-01 453 453 - 2 6 128 - 83
10 13-Oct-01 - 446 - 2 7 135 - 83
15

10
0.5
Heat Transfer Coefficient,
kW/m 2 .K
8
6
4
2
HTC Design Value = 2.491
Fouling Factor
Heat Transfer Coefficient
Design FF = 0.176
0.4
0.3
0.2
0.1
Fouling Factor, m m 2 2 .K/kW
0
0 100 200 300 400 500 600
Test Duration in Hours
0
Figure 1. Trends of Heat Transfer Coefficients and Fouling Factors
in Brine Heater of MSF Pilot Plant
Used Technos Balls
New Technos Balls
Figure 2. Photograph of Used and New Technos Balls of 29 mm Diameter
for Jeddah III Plant (Unit 9)

2000
Number of Damaged Balls
1500
1000
500
400
500
200
300
1460
60
0
10.2.99 10.3.99 13.3.99 15.3.99 17.3.99 21.3.99
Total Damaged Balls
Inspection Date
Figure 3. Physical Performance of Technos Balls in Jeddah III Plant
(Unit 9)
Number of Balls
2000
1500
1000
500
Cum. Damaged Balls
Cum. Lost Balls
0
0 100 200 300 400 500 600 700
Test Duration in Hours
Figure 4. Consumption Trends of Technos Balls During Test Period in
Jeddah III Plant (Unit 9)
17

Heat Transfer
Coefficient, kW/m 2 K
5
4
3
2
1
0
Heat Transfer Coefficient in Brine Heater
Fouling Factor in Brine Heater
Fouling Factor Design Value = 0.325
1.0
0.8
0.6
0.4
0.2
0.0
Fouling Factor,
m 2 K/kW
80
Flash Range, o C
75
70
65
60
Distillate, m 3 /hr
1200
1100
1000
900
800
9
Product Water Flow
Condensate Flow
200
150
100
50
0
Condensate , m 3 /hr
Plant Performance
Gain Output Ratio, (kg Water/kg Condensate)
8
Performance Ratio, (kg Water/2326kJ Steam)
7
Design PR Value = 7.09
6
5
0 100 200 300 400 500 600 700 800
Test Duration in Hours
Figure 5. Plant Performance During Test of Technos Balls in Jeddah III
Plant (Unit 9)
18

pH LTA
2.00
9
1.00
8.9
0.00
8.8
-1.00
8.7
-2.00
8.6
-3.00
8.5
200
pH - BRP
pH - BBD
Copper Content, ppb Conc. Ratio
M. Alkalinity, ppm
190
180
170
160
150
2
1.8
1.6
1.4
1.2
1
30
25
20
15
10
5
0
Copper - BBD (Before Ball Cleaning)
Copper - BBD (During Ball Cleaning)
Alkalinity - BRP
Alkalinity - BBD
CR - BR
CR - BD
0 100 200 300 400 500 600 700 800
Test Duration in Hours
Figure 6.
Chemical Analysis During Performance Test of Technos
Balls in Jeddah III Plant (Unit-9)
19

700
600
500
Lost Balls in Each Inspection
Cum. Lost Balls
Total Balls in System
500 500 500
583 583 583 583 583 583
Number of Balls
400
300
200
100
0
-100
216
177
156
146
126 131
122 128 135
85
30
6 7
-25
-39
-31 -24
1-Sep-01
3-Sep 5-Sep 7-Sep 10-Sep 15-Sep 23-Sep 30-Sep 7-Oct 13-Oct -01
Inspection Date
Figure 7. Performance of Technos Balls in Al-Jubail II Plant
(Unit 16)
44
Average Ball Size, mm
43
42
41
40
Average Size of New Balls = 42.5 mm
Minimum acceptable limit of balls size = 39.5 mm
39
0 100 200 300 400 500 600 700 800 900 1000 1100
Test Duration in Hours
Figure 8 . Trend of Average Ball Size of Technos Balls During Test
in Al-Jubail II Plant (Unit 16)
20

Heat Transfer
Heat Transfer Coeff.,
Coefficient, kW /m kW/m 2 K
2 o C
10
8
6
4
2
0
70
Heat Transfer Heat Transfer Coefficient Coefficient in Brine Heater
Fouling Factor
Fouling Factor in Brine Heater
Design HTC Value = 2.258
0.5
0.4
0.3
0.2
0.1
0
Fouling Fouling Factor, m 2 2o K/kW C/kW
Flash Range, o C
65
60
55
Water Production, m 3 /hr
50
1400
1300
1200
1100
1000
Product Water Flow
Condensate Flow
200
150
100
50
0
Condensate Flow, m 3 /hr
Plant Performance
11
Gain Output Ratio, (kg Water/kg Condensate)
Performance Ratio, (kg Water/2326kJ Steam)
9
7
5
0 200 400 600 800 1000 1200
Test Duration in Hours
Test Duration in Hours
Figure 9. Plant Performance During Test of Technos Balls in Al-Jubail II
Plant (Unit 16)
21

4
3
CR (BR/SW)
LTA
CR & LTA
2
1
0
0 200 400 600 800 1000 1200
Test Duration in Hours
Figure 10.
Chemical Analysis During Performance Test of Technos
Balls in Al-Jubail II Plant (Unit 16)
22

REFERENCES
1. Bohmer, H., (1993), On-load Tube Cleaning Systems and Debris Filters for
Avoidance of Micro- and Macro-Fouling in MSF Desalination Plants, Desalination,
93, 171.
2. Al-Bakeri, F. and El Hares, H., (1993), Optimization of Sponge Ball Cleaning
System Operation and Design in MSF Plants, Desalination , 92, 353-375.
3. Al-Sofi, M. A., Khalaf, S., and Al-Omran, A., (1989), Practical Experience in Scale
Control, Desalination, 73, 313-325.
4. Hamed, O.A., Al-Sofi, M. AK., Mustafa, G.M., Bamardouf, K. and Al-Washmi,
H.N., (2001), Overview of Design Features and Performance Characteristics of
Major Saline Water Conversion Corporation (SWCC) MSF Plants, WSTA 5 th Gulf
Water Conference, 24-28 March, Doha, Oman.
23

Appendix
An Overview of On-Load Sponge Ball Cleaning in SWCC MSF Plants:
Plant
Chemical
Treatment
Ball/ Tube Ratio
BH
HRC
Frequency of
Ball Cleaning
No. of cycles per
operation
Jeddah
II Acid 0.296 0.236 1 Oper./ Week 3 Cycle/oper
III Antiscalant 0.29 0.665 3 Oper. / Day 4 Cycles / Oper.
IV Antiscalant 0.251 0.370 2 Oper./ Week 10 Cycles / Oper.
Ph-I Antiscalant 0.450 0.427 3 Oper. / Day 8 Cycles / Oper.
Jubail
C2 &
C3
Antiscalant 0.342 0.324 3 Oper. / Day 8 Cycles / Oper.
C4 Antiscalant 0.270 0.257 3 Oper. / Day 8 Cycles / Oper.
C5 Antiscalant 0.300 0.302 3 Oper. / Day 8 Cycles / Oper.
Khobar II Antiscalant 0.453 0.458 3 Oper. / Day 9 Cycles / Oper.
Yanbu I
Antiscalant 0.243 0.249 3 Oper. / Day 12 Cycles / Oper.
Acid 0.243 0.249 1 Oper./ Week 12 Cycles / Oper.
Yanbu II Antiscalant 0.345 0.346 3 Oper. / Day 13 Cycles / Oper.
Al-Shugayg Antiscalant 0.22 0.22 3 Oper/ Day
8 Cycles / Oper.
(16 for high TBT )
Al-Shoaiba Antiscalant 0.251 0.253 3 Oper/ Day 3 Cycles / Oper.
Al-Khafji Antiscalant 0.351 0.351 One Oper/ Day 9 Cycles / Oper.
24