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History, experience and economics of water production in Kuwait
HISTORY,
EXPERIENCE
OF WATER
AND
PRODUCTION
ECONOMICS
IN KUWAIT*
ISTRODUCTIOS
Kuwait had practicalig no pottblc water and was relying, between 1925-50. on a very limited supply of imported water from Shat Al-Arab. Iraq. by boat. In 1950, th;: Kuwait Oil Cornpmy supplied the city with 80.000 igpd.** H. H. The Amir of Kuwait ordcrcd the firbt one million igpd submerged tube sea water distillation plant which produced water in 1953 and this was followed in 1955 by a similar plant of one million gallon capacity-. Then in 1997. the first of four lj2 million igpd flash type cvaporstors was commissioned. in 1960 another flash evaporation plant was commIssioned which consists of two units each of one million igpd capacity. Five 1 million igpd plants arc under construction and will be commissioned soon. Ollter
supplies
Brackish water is available at Sulibiyah of TDS+** of 4,500 ppm and 18 million igpd arc produced there. Also in 1961 ground water was discovered at Rawdatain and Umm Al Aish where about 5 million igpd at TDS of 1,000 are produced. An elcctrodinlysis plant lo produce 200.000 igpd from brackish water was commissioned recently and is still under observation.
The distillation plants are installed at the Shuwaikh (160 mW) and Shuaiba (210 mW) steam power stations. On both sites sea water intakes are common to power station and evaporators. Pass out steam from turbo alternators or steam directly from boilers is used in the distillation plants. Fuel for the boilers is natural gas from oilfields obtained at no charge and gas oil is a standby fuel.
* P;lpcr read at the inter-R&onal Seminar on the Economic Application of Water Desalination New 't'orli. Scptcmbcr 22 -October 2. 1965. Published by the kind permission of the Resources and Transport Division, United Narions. New York. l * Imperial gallons per day. l * l Total dissolwd solids.
77 Dediffalion.
I (1966)
I-100
7s
M. SUBMERCXD
H.
.\LI
TUBE
EL-SAIE
TI’PE
EVAPORATORS
The piants were supplied by the Westinghouse tUSA) and Weir (UK) companies respectively. Each consists of ten triple effect evaporators of 100.003 igpd, commissioned in I953 and 1955 respeetivefy. Each evaporator consists of three horizontal (steel, in case of Shuwaikh A and cast iron for Sftuwaikh B) cylindrical shells each with horizontal tube bundles of cupro-nickel 70/30 and a horizontal shelf tube condenser. All pumps are motor driven. with cast iron casing, phosphor bronze imfxffers and stainless steel shafts. At the t;eginning, on Shuwaikh A plant. scale formation was prohibitive and required mcxhanicaf cleaning.
Labomtory
and cxrensivc site rexarch
of diffcrcnt treatments,
acids, inhibitors
and running conditions leads to the foffowing mode of operation: continuous dosing of XEL water feed with 2.5 ppm of Hagevap.* For plant B, additional fed of ferric chloride, each afternate week at f50 ppm. Top brine temperature and steam. respectively, 180°F and 225°F. Brine concentnting
(ration
of chlorides):
Less than 3.
Scale crxking every 7 to 10 days was found necessary. Scale cracking routine, in short, is the stopping of the evaporator and admitting Iive steam to the steam tube bundles in each effect and then admitting sold sea water rapidly to the shell to give the scale a sudden shock or contraction and hence the scale outside the tubes cracks, flakes and drops inside the shelf and is then blown down and washed through a drain valve in each shelf. WC1acid boost, two to three times per year has fxen very effective. Acid is used in cleaning at every overhauf. The plants have been running very satisfactorily and require overhaul every ten thousand running hours. Recirculation of brine to first and second efkts in plant A to increase brine v&city has proved ineft’cctive because it increases power consumption. It was found that calcium sufphate forms in the evaporator at lower temperature and concentration of brine is greater than in laboratory tests. This is, in the author’s opinion, due to Iocal fxGIing and fow mass transfer at the heating surface which means high temperature and concentration as the brine bubbles. Tests were made with a permanent magnet apparatus supposed to change the properties of sea water ions and molecules and hence prevent scale formation without any che.rnicaf treatment. These tests proved to be ;1 complete failure
Slttrrwikl: c’ md D plut
fs
As this plant was the first ffash evaporator to produce distitfate from sea water at such a rate of production, it was a turnink point in the history of sea water distillation -_*
Hagmap
ad
PD.8
are
commercial scale i retention additixvs based on
p&phosphates.
Desafinafion,
1 (1966)
l-100
WATER
and its success encouraged
PRODCCTIOS
companies
IN
KUWAIT
79
all over the world to carry out a lot of work
on flash distillation.
Four flash type evaporators each with four stages, one stage over the other with the main heat input section over the top of the four stages and each unit of 525.000 igpd production, were supplied by the Westinghouse Company. The first unit was commissioned in 1957. Many modifications were introduced to the original offer as a result of our site experience and results from prototype tests at Works, mainly on brine control, purity of distillate and scale formation. The plant ran very satisfactorily except for the distillate purity and this was cured by introducing a suitable monel demister in the stage at lower vacuum. Due to choking in the heater water box, scale formation increased. Strainers wcrc introduced in the sea water feed make up which stopped this trouble and hence water strainers will be used in all future plants. Fixed speed electrically driven pUnIFS resulted in ditlicult start-up and control. The plant is running with top brin c temperature of 194’F. 5 ppm Hagevap is administered to sea water feed and 150 gallons of HCI at 33:,, concentration are used to loosen scale in tubes once a year; the brine blow down concentration ratio is 2. Acid cleaning of the heater is needed only every 8 to 10 thousand hours. The shell and all interior pnrts 3rc mild steel; the tubes arc Co Ni 70/30 and the pumps of st3inless steel. Slmiwikh
E pim t
Two units of 19 stages. arranged in 3 tiers, each producing one million igpd, were commissioned in 1960. The construction materials are similar to plant “C”. All information avsilablc from manufacturers was collected before design specifications were issued. The best commercial offer was submitted by the G. and J. Weir Company, but a lot of alterations were negotiated before the order was placed. The origin31 offer was for 26 stages, 3 for heat rejection and 23 for heat gain. The new feature in this design was the prescncc of two separate heating coils in the heat gain section, one for recirculating brine, the other for sea water feed. The sea water feed from the outlet of the heat gain section is admitted to a separate deaerating heater and then mixed with the recirculating brine from the heat input heater outlet. The advantage of this design is clear from the points of view of heat transfer and corrosion in the flash chamber. This feature was rejected because of our previous experience with the very aggressive corrosion nature of Kuwait Bay sea water at the boxes, while we usuaily have little or no trouble with concentrated brine in these boxes. The plants were redesigned to have only recirculating brine in the heat gain section. To ensure interstage brine control, a series of tests on a prototype control weir were carried out in the presence of the author. The type of weirs selected was agreee upon after changing the height of the flash chambers and adding batlle plates. The heat exchange surface in the heater is practically double the surface olfered; 3gain we insisted on this increase from previous experience at the site. Desalination. 1 (1966) l-100
80
M. tt.
ALf
EL-SAIE
Laboratory tests at Weir Works were carried out &fore final design approval and major nrodifiwtions were introduced to avoid corrosion of sea water in the boxes. A sensitive steam control of the heater provides very smooth operation. The plant is running very weI1 with top brine temperature of 194°F. Hagevap dosing to sea water feed is of 5 ppm. The brine concentration ratio is 2. Acid cleaning is undertaken every 10,000 hours, Situ~*aiMr F (2 rcrtits) urtd Shuaiba A (3 rmirs) plants These plants now under construction consist of 5 units of one million igpd each, have 30 stages in two tiers and are similar in principle and running conditions to plant E, but with less specific heat ~nsumption. (Specific heat ~nsumption in BTU per lb. of distillate for C and D is 345; for E 184.75; for F 143.7). Also the whole plant has remote automatic control from a central control room at each site. Due to the long experience at the site 2nd the little sign of erosion and corrosion
on the exchange surf&es in most of the stages, we decided to use cupro_nickel70/30 only in the stages where the heat transfer surfaces were exposed to heavy corrosion (in top stages where CO2 release is maximum and in the bottom stage where there is O2 liberation due to presence of feed make up) and also ir. the main brine heater. In the rest of the evaporator. aluminium brass has been used. The sea water supply to plants wilt have a constant temperature all year. Laboratory tests on prototype of brine control, purity of distillate and dimension of stages were carried out before final design. The first unit was just in the course of being commissioned when this paper was despatchcd (June 1965). CORROSIOH
PROBLEMS
Szdphate reducing bacteria The presence of sulphate i-educing bacteria in Kuwait sea water results in heavy corrosion in steel and cast iron components in contact with sea water.
CO2 attacks the interior pipes. Prewntive
of the flash chambers,
the ejector condenser
and distillate
nterlds
(a) Continuous
ch!orination
of sea water
to kill bacteria
and
marine
growth.
(b) Cathodic protection. (c) Applying paint and coatings: (i) Hot applied bitumastic enamel for pipes and pumps for sea water. (ii) Rubber lining of sea water boxes. (iii) Zinc-rich primer and chlorinated rubber paint in other parts. L?e3uZifruriun, I (1966) i-100
WATkR
DROIxc-TlCS
1s
IcL~WA1-f
(4 Careful choice of materials for the different components. (cl Separate venting of first and last flash stages.
(0 Clcvating of ejector (6) Injection of Ca(OH),
condensct tcmperaturc. and NaHCOz to distillate W.\TER
PRODUCTIOY’i
mains.
COST
in Table I below arc for one million ispd plants of each type on All cakuintions full production all year, except for outages other than standby. O\erhead charge< of 75:‘; on wages and salarxs are included. Fuel is free except for dcprcciation and maintenance of the gas line and accessories. FURTHER
DATA
Appendix :I contains chemical analyses of incoming of the conccntratcd brine at the plant outlets. Appendix various plant% Figures l--l% which are self explanatoq, of the evaporator’s and some operating records. TABLE
Plarrr
1
C and V
and Skurrih A K.D. __ ._
X.0.
K.V.
K.V.
IO.335
IO.-iC9
1,616
2,6lh
2.616
cost for mtc.c.
11,38-l
13,732
I.216
I.200
1,200
cost (\\‘@rkShoFs)
7,429
1.613
332
331
332
20.971
11,250
6,ooo 4.376 -
6,m 4.376 -
A-.0: hl3intimncc MzaxiJ xltie.
sea water, scale deposits and B gives further data on the show photos and diagrams
Opcratian
\tagcs
uags
Cc*t or PD
22,524 2.109
8
_-
Cost of ferric chloride
I .%I6 1,380
4.376 -
Ccrst of acid fax cluning
1.125
1.125
37s
375
375
Cost of chlorine
8,175
8,175
5.017
3.190
2.100
Cost of clcaicity consumed
11,500
104.200
13,900
Cost of steam consumed
43,800
42.600
36.30
1,300 17.600
12,800
118,000 -
86,claO -
46,200
23,300
27,000
34.500
17,soO
20.250
121.532
60,289
56.003
109.832
48,693
49,253
330
330
Dqreciation
of unit (15 yrs)
Depnxintion
of Unit (23 yts)
Total cost bastd on 15 yrs depreciation Total cost based on 20 yrs dcpre&tion Production in million Imp. gal&car Ctit of 1.000 Imp. %;rlsin Iils on depreciation of 15 years BYeat l
One K.D.
237,341
197.407
-
340
300
290
330
190 -
650 -
368
173
169
336
144
149
.= 1,OtJOfils == S2.8 = El. Dedimrion.
1 (1966) l-100
SlJS!SfAR%-, COSCLUSIOSS
ASD
RECOSlMENDATIONS
1. The multistage sea water flash type evaporator is the most reliable equipment to produce distillate from sea water at reasonable cost and the submerged tube type should be limited to very small plants where a lot of outage is possible. of scale formation is a complicated subjlrt and local conditions (nature of sea water. design conditions, chemical treatment etc.) and hence the writer adv%es that any authority deciding to install a sea water distillation plant cf large capacity should build first a unit of reasonable size and carry out tests on scale formation and chemical treament before committing itself to the full-scale installation required. Kuwait is iucky in that no iron is present in its sea water; in other places presence of iron has caused a lot of trouble with respect to the appropriate dosing with Hagevap and very complicated sludge and scale were formed. Acid treatment is, in the writer’s opinion, the best for large units, especially in countries paying for fuet, provided that reliable pH and dosing controls are applied. 2. The mechanics
are of major importance
specifications when ordering a plant cannot be under the guidance of experts who hate site experience and who appreciate the difference in effort required between receiving the offers and placing the order. Prototype tests in the laboratory or on site are sometimes of great importance and can save a lot of time and money. 3. The importance
underestimated;
of clear-cut
these should !x prepnrcvt
4. Much work still needs to be carried out to reach a practical, drfinitc correlation between size of flash stages and their duties especially for units of large capacity (1 m_rpd and over), and also for brine control. 5. Choice of materials, chemicals and coating is, in the writer’s opinion. the principal factor which leads to savings in capital as well as in maintenance charges.
6.
The
steam water ratio is given for different plants in the heat flow diagrams but in Kuwait this is not the important factor due to free fuel and hence the ratios were chosen for availability of power installation and economy. 7. Flash evaporators are sensitive to variation in sea water temperature, brine temperature and feed inputs and the writer advises that changes should be r&uced to a minimum and the automatically controlled and not to manual equipment should be suitable for easy start up and shut down. 8. The cost of production 1953 and the present.
from sea water distillation
operation.
has fallen rapidly
Dcsulinmiun.
Also
between
1 (1966)
I-100
53
TABLE SE&
._ -. - - _ Total dtswlred solids. m ppm Total allalinity. CKO %,in ppm Chlorides, Ct. in ppm Sufphata, SOI. in ppm Permanent hardnw. CKO?;. in ppm T~aqwrsry hardness. CaCO1. in ppm Total h;lrdncrss. CaCOI, in ppm Calcium. Ca’*. in ppm M3gncG~m. *fg’ +, tn pprn Bromine. Br -, in ppm Silica. Sir&. m ppm w Neutral clcxtri~~t conductivity. mitromhos Maximum sea xwtcc tcmpcraturc Mmimum se3 wtcr trmpcraturc
tat
\VXTFR
!
ANhLYSiS
Siwwaiki~ sitr from Kuwuit &?v -48:200 150 24,800 3.500 7.950 la0 8.050 400 I .ciYo 80 5 5.8 76.iwO 90 F 58 F
PI 10-C
Shrraitvr sitt- from the Arabian Gulf _._. ._ _... ..-._. . -J2,@30 135 23,100 3,IcJO 8.400 100 8,500 500 1,465 SO 5.0 8.3 70,500 95’F 58-F
Srthnrrr.gcd rrthc gpr cwpmz~w.~ Shuwaiih A wrth 2.5 ppm PD.8’ traxtmetlt Shw\aikh B uith 150 ppm ferric chloride and 2.5 ppm PD.Y treatment 2frd &Tr
I ri Cjfjkr
___ MgKii)~ CzlCOJ
.
3rd eflect
B h 0 10 . - 0.0_ _ 0’ ,U 10 n* 0, .a,, -“..-_-._--_ _. _ .__ :\
40.0 49.6
-
7.5 1.3 -
casot
SiU: FczO,
R
X
65.0 15.0
5.5 90.0
75.0 10.5
1.5 5.6 12.5
1.5 3.5 -
I.8 6.8 4.2
41.5 48.2
1.0 5.2 -
B %___ 72.0 4.0
3.5 4.5 15.2
(b) FZadx rope c~npora:urc Shuwai(rh C and D with 5 ppm PD.8 Shuwiiikfi E sith 4 ppm PD.8 trcxmcnt __ . . __. - I - - .“__.__. _-_ Organic matter SiOz Sdublt phosphates Ns,PO+ Xig@D& MgtOII), C&O, CrlCOJ
_ . -_ _ _.-.i-
C urrJ D (P,) _ -. .____..____10.5 6.1 2.5 23.4 40.5 4.8 6.5
Et:.) ._ ..^- ._ ____-8.5 6.5
3.6 22.8 42.3 1.5 4.2
NaCl
5.1
8.0
FC&
Trace
1.2
* See note on page 78. ~~S~~~~~~~, I (1966) l-100
EYAPOR4TOR
----
___
_. ._
__
BRISE
AS4LMIS
Sbuwikh A .__ -.-. MO.ti101,490 9.6 SO 285 ~0.000 6 ,890 16,875 f ,ooo 3.195
_
Conductivity T.D.S. in ppm PH Total c;lusiic ~5 NaOH in ppm Totnl 3.1 kalinily 3s C&O, in ppm Chlorides 3s Cl- in ppm Sulphates as SO:- in ppm Total hardness as COCOJ in ppm Ca!cium 3s cLll+ in ppm Mqqnesium a M& 4 in ppm
APPENDIX
Arca
1st ElfI33 2nd Effect 3rd Effect Condenser
6’1’ 6’1’ 6’1’ 6’1’
2.150 2.150 2,220 1.600
dia. __~_____.____ 1st Effect 2nd Effect 3rd Effect No. 2 Preheater No. 3 Prehtiter Condenser and No. 1 Preheater
9’ 9’ 9’ 22, m 2’2’
6.300 15.615 940 3.320
Etaporaror
114,175 9.5 So 385 58.500 8.150 19.125 1.200 3.920
rt.h.v
Gauqz
1.3.
I’ 1’ 7:s’
IS IS IS
Lrnyrh
2 . Ii’8 I!‘-$; 2 . t1?31j42 . IG’I l/4’ IS’1 7/S’
17 kVA 66.5 LVA
11
EV9PORATOR
: SlIUWAIIil
B PLA?.T
of
/warinK surface fr = . -.-.---. _._ “00 “Cl0 _._ 2.200 200 2Oc 1.700
Es aporafor tubzs h’o. ny ..___ 818 818 S18 S8 88 750
3’8’ 300 Electric load:
9.1 70 310 dS.oco
6.315
i-
-718 -728 540 388
TYPE
Area Shell
180:ooa
94.510
15.000 9:0 3.320
----_I_ ‘V@. off O.D.
TABLE TUBE
I49.cloo
1
Elrxtric load without recirculation Electric load sith recircul;ltion
SL’RUERGEO
143.OCO 90.705 94 a5 ‘775 17.900
of
hrariry surface .fr 1
fira.
Shuwaikh E
Shmaikb Cond D
B
TABLE
ShCll
Slrurmihh B
32
O.D. Length Garrge _- ___-_____ __._ ____ _._._ --..-3:116 14’1 3/v 3j.y 14’1 3X 16 14’1 34’ 314’ 16 1’ 16 8’3 l/1I’ 16 8’3 l;r 3:418 11’10 1/r 3pr 18
4Ci kVA Demfimfiun.
I (1966) 1-z
--
WATER
PRODUCTION TABLE
FLASH
t3 PE EVAPOR
\TOR:
IN KUWAIT
III SilUWAIKt4
Evaporator
surfocc ff-
----.
---. rejection
Hat Hut blat&
-..... sxtion
D PLAhT
of
Area
heaIing
Hmt
C AND
.- _.
A’o. of
O.D.
tubes Gauge
Length
_._. _ _..__________ _ __._..___ .._ _______.._.
Wi.UfL?r velocity inside r&es ftlsec
I
KS00
1.288
7,0x’
18
30’
gain section
3
26.400
3,564
7jP
I23
30’
6.5
input
I
7mo
1 ,mJ
7)s’
IS
28 ‘6’
6.5
1
2,000
?/‘a’
18
sation
up c\;rp. Ektric
lad:
588
6.5
340 kVA
TABLE ITPE
FLASII
IV
E\‘APORATORS SHUN’AIKII
E PL.A?cT tVa:er
Area of ‘VO. 01
hearing surfice /I2
rragrr ___
__- _ . _--
-.
.--.
Hat
rcjcction szction
Heat
tin
Heat
input
E%oporaror rubes so. ofl
_.
section
I6
section
I Elmtric
I4,f.M
1’
0.904’
20’6’
6.5
1,530
1’
0.901
I_(%-
6.5
6.000
1o.d
: 7S kVA
FLAW
TYPE
No. of 3 rages
gin
Hut
input
_-_I_.--_..-._L scmion 3
section
V StiUwAIKII
E\APORATOR
Are0 of hearing
F PUTT
Wafer t efocily
Et aporator tubes
inside tubes fr/sec
SlU,=O-C ff2
Heat
Length
---
TABLE
__-_--__ rcjmion
I.D.
1 77.400
Hat
O.D.
velocity inside rulrsk fi/SCC
x0.
off
O.D.
---_- ----.-----..12,570
I.D.
Length
___.-_-
-
---
4.286
1’
0.90)
20’7 718’
6.5
27
138,780
2-+,lOo
1’
0.9o.r
20’7 718’
6
1
5.155
I.676
1’
0.904*
12’8 718’
7
section Electric
toad:
60 kVA
Desaiimdon.
1 (1966)
l-100
86
hf.
H.
ALI
EL-SAIE
DCSUiiMfiOII,
1 (1966)
l-100
87
._ _ _ ,. .__
, .
.__
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.-_____.
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c--
-,
-
-
L
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.
sT*TION
.
CI
,__^_
e
...a
.. ‘2
y:-
$!+., -.-
.
.
yyzg
I
L
-
‘:
..
-0 , 5 -_
’
.i.,
-
:;2=
__,-p
_I
-
-.
<.‘
..g
,
.:.
__.
. .
e-fE$
STATICN .-.
.
.;
,
;.;
.-..
._
;_
<.i;
J,rtu*~o-4_..
.-__ .
’
&A-L-
_ ____--_ __-
__.+ B
. .
7---‘
c
_;o:_.
*
-.---
.
\
-
i
_A
-----7
-
r?
1
_._-,
- -
P&ES---j,
-
STATON _
_:,__
C _
0
cs3
I . t
1..
-_
;-:
D
_
_.._._ -
_---_-._-
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____
7
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z_-_-_r--_ -
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.
--
:
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Ye
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<.-“” ._ --- -.s
--I,-._
._
_..
--.
-
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I.
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c__
--f
L_-Yz-Y-~y
-
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j
_..
,__-__
_ ,
--
-
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-.-l
:_-T-
I
-
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-
I_,<_.
, --._?
I7
\-- --L
s---T
C”Y’_.
__.___
._ __ _.
I’
_ _ - I’
Dcsali~arion,
1 (1966)
l-100
M.
H. ALI
EL-SUE
Figure 3 One e\sporaror
on ,C,
L.
Il.-P
-r
SL
Shuwaikh
r
e
--
-
-
-__
_
_ __
A disriilation plant
-_ .--.------ -.-.i-I
&z-a
a-PInu.,,
~..
-.
.:a’.
-%r’
-.
-._
-__.,
. .
_.
.
-
.. ._
. .
i
. ..; ,
OJD,.
Submerged
tube type c\zporator. Shuwikh A plant (Hithcut rccirculztion) density as NaCl. Ratio 2-PD.& Inja-tioo 2.5 ppm
Desafimrion. 1 (1966) I-100
Figure Submcrgcd
5
t&c type c\aporator. ShuHatih A plsnt (with rc-circulation) mnstry as NaCI. Ratto 2-PD.& Injection 1.5 ppm
Figure 6 One evaporator
Shuwaikh
B distilla’.ion plant
Desalination,
1 (1966) l-100
M. H. ALI
H-1 -
EL-SAIE
flow diagram, submerged tube type sea water evaporator. Shuwaikh B plant Specific heat consumption 120 Btu lb of distillate - - - - - Distilhtc s=3 water and brine Swam and condensate
One cvapotxtor
Figure 8 Shuwaikh C and D distillation
plant
WATER
PRODUCriON
IN KUWAIT
Figure 9 Heat flow dugram. Flash type set wdfcr e\apcjratot. Circulation ratio 13.4 - Sfxctfic: heat consumption
Shutiaikh C and D plants 345 Btuiib of distillatc
BRINE ORIFICI EXCHANGE
B .: h
DISTILLATE PUMP SUCTION
BRfNE PUM SUCTfOf
Figure 10 Flash type sea Natet evaporator Shuwaikh Section in A stage
C and D
M. H. ALI EL-SALE
Figure Flasch type e\apo:ator. Tap brine tsmp. 194 F--!knsiiy
II Shu\taikh
as NaCI
ntio
C ,~lant
1.8-PD.8 injection 5 ppm
ZJSO P P H.
4.4a2.750 P P H
FEED
L1 ,.25,000
l CH
BLOW DOWN ‘\834.wo c P ” flO’F
1
!
I
BRINE REC. Pi.Xf
Figure 12 Heat flow. diagram, flash type sea water evaporator. Shuuaikh Circulation ratio ItSpccific
heat consumption
181.75 &u/lb
E plant
of distilatc.
Desulinofion, 1 (1966) l-100
r A t 1
Figure
13
Shuuaikh
E
distillation plant
1 ,
$-------”
1
WEAT EXCHANGE TUBES
0RIF:CE .--. .-_ FOR VENT
/
OIST.
FRO?4
PREVIOUS
_
DISTILLATE
STAGE
--
fz g)-
__..--. .-.__-.
_
ORIFICE p-., ‘-.’
84
--
:1
:’
- ------ _____._:___ ----_----;i
ET
:
.___
:
*f
-
_z:
Figure
_-_
1-t
Flash type sea
BRINE WEIR
water cvaporator Shuwaikh
E
section in A stage
A \;uics 4’-2 10’4
--BRINE ENTRY
from
I
3/4- to 311’
_--. A
_.-_ Desdinufiun,
1 (1966)
I-100
91
VENT ----
--_ A.__ -.-_
DIST.
FROM
PREVtoUS _-
Figure
15
Flash type sea water cvaporalor Shuuaikh F
!
. -=
DlSTlLiATE O!I_FJcE ) - - _:-_, _^._-
-_
STAGE
-
S‘xtion in Astagc A varies from
3’-8’ to 9’ -
PIPE
-i.P
RINE WEI 1 1
6’
Shuwaikh
Figure 16 F distillation
plant
95
WATER PRODCCTfON IN KUWAIT
c
Total distil!atc
Figure 18 water production from Shuwaikh
distillation
plant
Desu/inafion, 1 (1966) l-100
EXPERIENCE
OF WATER
AND
PRODUCTION
ECONOMICS
IN KUWAIT*
ISTRODUCTIOS
Kuwait had practicalig no pottblc water and was relying, between 1925-50. on a very limited supply of imported water from Shat Al-Arab. Iraq. by boat. In 1950, th;: Kuwait Oil Cornpmy supplied the city with 80.000 igpd.** H. H. The Amir of Kuwait ordcrcd the firbt one million igpd submerged tube sea water distillation plant which produced water in 1953 and this was followed in 1955 by a similar plant of one million gallon capacity-. Then in 1997. the first of four lj2 million igpd flash type cvaporstors was commissioned. in 1960 another flash evaporation plant was commIssioned which consists of two units each of one million igpd capacity. Five 1 million igpd plants arc under construction and will be commissioned soon. Ollter
supplies
Brackish water is available at Sulibiyah of TDS+** of 4,500 ppm and 18 million igpd arc produced there. Also in 1961 ground water was discovered at Rawdatain and Umm Al Aish where about 5 million igpd at TDS of 1,000 are produced. An elcctrodinlysis plant lo produce 200.000 igpd from brackish water was commissioned recently and is still under observation.
The distillation plants are installed at the Shuwaikh (160 mW) and Shuaiba (210 mW) steam power stations. On both sites sea water intakes are common to power station and evaporators. Pass out steam from turbo alternators or steam directly from boilers is used in the distillation plants. Fuel for the boilers is natural gas from oilfields obtained at no charge and gas oil is a standby fuel.
* P;lpcr read at the inter-R&onal Seminar on the Economic Application of Water Desalination New 't'orli. Scptcmbcr 22 -October 2. 1965. Published by the kind permission of the Resources and Transport Division, United Narions. New York. l * Imperial gallons per day. l * l Total dissolwd solids.
77 Dediffalion.
I (1966)
I-100
7s
M. SUBMERCXD
H.
.\LI
TUBE
EL-SAIE
TI’PE
EVAPORATORS
The piants were supplied by the Westinghouse tUSA) and Weir (UK) companies respectively. Each consists of ten triple effect evaporators of 100.003 igpd, commissioned in I953 and 1955 respeetivefy. Each evaporator consists of three horizontal (steel, in case of Shuwaikh A and cast iron for Sftuwaikh B) cylindrical shells each with horizontal tube bundles of cupro-nickel 70/30 and a horizontal shelf tube condenser. All pumps are motor driven. with cast iron casing, phosphor bronze imfxffers and stainless steel shafts. At the t;eginning, on Shuwaikh A plant. scale formation was prohibitive and required mcxhanicaf cleaning.
Labomtory
and cxrensivc site rexarch
of diffcrcnt treatments,
acids, inhibitors
and running conditions leads to the foffowing mode of operation: continuous dosing of XEL water feed with 2.5 ppm of Hagevap.* For plant B, additional fed of ferric chloride, each afternate week at f50 ppm. Top brine temperature and steam. respectively, 180°F and 225°F. Brine concentnting
(ration
of chlorides):
Less than 3.
Scale crxking every 7 to 10 days was found necessary. Scale cracking routine, in short, is the stopping of the evaporator and admitting Iive steam to the steam tube bundles in each effect and then admitting sold sea water rapidly to the shell to give the scale a sudden shock or contraction and hence the scale outside the tubes cracks, flakes and drops inside the shelf and is then blown down and washed through a drain valve in each shelf. WC1acid boost, two to three times per year has fxen very effective. Acid is used in cleaning at every overhauf. The plants have been running very satisfactorily and require overhaul every ten thousand running hours. Recirculation of brine to first and second efkts in plant A to increase brine v&city has proved ineft’cctive because it increases power consumption. It was found that calcium sufphate forms in the evaporator at lower temperature and concentration of brine is greater than in laboratory tests. This is, in the author’s opinion, due to Iocal fxGIing and fow mass transfer at the heating surface which means high temperature and concentration as the brine bubbles. Tests were made with a permanent magnet apparatus supposed to change the properties of sea water ions and molecules and hence prevent scale formation without any che.rnicaf treatment. These tests proved to be ;1 complete failure
Slttrrwikl: c’ md D plut
fs
As this plant was the first ffash evaporator to produce distitfate from sea water at such a rate of production, it was a turnink point in the history of sea water distillation -_*
Hagmap
ad
PD.8
are
commercial scale i retention additixvs based on
p&phosphates.
Desafinafion,
1 (1966)
l-100
WATER
and its success encouraged
PRODCCTIOS
companies
IN
KUWAIT
79
all over the world to carry out a lot of work
on flash distillation.
Four flash type evaporators each with four stages, one stage over the other with the main heat input section over the top of the four stages and each unit of 525.000 igpd production, were supplied by the Westinghouse Company. The first unit was commissioned in 1957. Many modifications were introduced to the original offer as a result of our site experience and results from prototype tests at Works, mainly on brine control, purity of distillate and scale formation. The plant ran very satisfactorily except for the distillate purity and this was cured by introducing a suitable monel demister in the stage at lower vacuum. Due to choking in the heater water box, scale formation increased. Strainers wcrc introduced in the sea water feed make up which stopped this trouble and hence water strainers will be used in all future plants. Fixed speed electrically driven pUnIFS resulted in ditlicult start-up and control. The plant is running with top brin c temperature of 194’F. 5 ppm Hagevap is administered to sea water feed and 150 gallons of HCI at 33:,, concentration are used to loosen scale in tubes once a year; the brine blow down concentration ratio is 2. Acid cleaning of the heater is needed only every 8 to 10 thousand hours. The shell and all interior pnrts 3rc mild steel; the tubes arc Co Ni 70/30 and the pumps of st3inless steel. Slmiwikh
E pim t
Two units of 19 stages. arranged in 3 tiers, each producing one million igpd, were commissioned in 1960. The construction materials are similar to plant “C”. All information avsilablc from manufacturers was collected before design specifications were issued. The best commercial offer was submitted by the G. and J. Weir Company, but a lot of alterations were negotiated before the order was placed. The origin31 offer was for 26 stages, 3 for heat rejection and 23 for heat gain. The new feature in this design was the prescncc of two separate heating coils in the heat gain section, one for recirculating brine, the other for sea water feed. The sea water feed from the outlet of the heat gain section is admitted to a separate deaerating heater and then mixed with the recirculating brine from the heat input heater outlet. The advantage of this design is clear from the points of view of heat transfer and corrosion in the flash chamber. This feature was rejected because of our previous experience with the very aggressive corrosion nature of Kuwait Bay sea water at the boxes, while we usuaily have little or no trouble with concentrated brine in these boxes. The plants were redesigned to have only recirculating brine in the heat gain section. To ensure interstage brine control, a series of tests on a prototype control weir were carried out in the presence of the author. The type of weirs selected was agreee upon after changing the height of the flash chambers and adding batlle plates. The heat exchange surface in the heater is practically double the surface olfered; 3gain we insisted on this increase from previous experience at the site. Desalination. 1 (1966) l-100
80
M. tt.
ALf
EL-SAIE
Laboratory tests at Weir Works were carried out &fore final design approval and major nrodifiwtions were introduced to avoid corrosion of sea water in the boxes. A sensitive steam control of the heater provides very smooth operation. The plant is running very weI1 with top brine temperature of 194°F. Hagevap dosing to sea water feed is of 5 ppm. The brine concentration ratio is 2. Acid cleaning is undertaken every 10,000 hours, Situ~*aiMr F (2 rcrtits) urtd Shuaiba A (3 rmirs) plants These plants now under construction consist of 5 units of one million igpd each, have 30 stages in two tiers and are similar in principle and running conditions to plant E, but with less specific heat ~nsumption. (Specific heat ~nsumption in BTU per lb. of distillate for C and D is 345; for E 184.75; for F 143.7). Also the whole plant has remote automatic control from a central control room at each site. Due to the long experience at the site 2nd the little sign of erosion and corrosion
on the exchange surf&es in most of the stages, we decided to use cupro_nickel70/30 only in the stages where the heat transfer surfaces were exposed to heavy corrosion (in top stages where CO2 release is maximum and in the bottom stage where there is O2 liberation due to presence of feed make up) and also ir. the main brine heater. In the rest of the evaporator. aluminium brass has been used. The sea water supply to plants wilt have a constant temperature all year. Laboratory tests on prototype of brine control, purity of distillate and dimension of stages were carried out before final design. The first unit was just in the course of being commissioned when this paper was despatchcd (June 1965). CORROSIOH
PROBLEMS
Szdphate reducing bacteria The presence of sulphate i-educing bacteria in Kuwait sea water results in heavy corrosion in steel and cast iron components in contact with sea water.
CO2 attacks the interior pipes. Prewntive
of the flash chambers,
the ejector condenser
and distillate
nterlds
(a) Continuous
ch!orination
of sea water
to kill bacteria
and
marine
growth.
(b) Cathodic protection. (c) Applying paint and coatings: (i) Hot applied bitumastic enamel for pipes and pumps for sea water. (ii) Rubber lining of sea water boxes. (iii) Zinc-rich primer and chlorinated rubber paint in other parts. L?e3uZifruriun, I (1966) i-100
WATkR
DROIxc-TlCS
1s
IcL~WA1-f
(4 Careful choice of materials for the different components. (cl Separate venting of first and last flash stages.
(0 Clcvating of ejector (6) Injection of Ca(OH),
condensct tcmperaturc. and NaHCOz to distillate W.\TER
PRODUCTIOY’i
mains.
COST
in Table I below arc for one million ispd plants of each type on All cakuintions full production all year, except for outages other than standby. O\erhead charge< of 75:‘; on wages and salarxs are included. Fuel is free except for dcprcciation and maintenance of the gas line and accessories. FURTHER
DATA
Appendix :I contains chemical analyses of incoming of the conccntratcd brine at the plant outlets. Appendix various plant% Figures l--l% which are self explanatoq, of the evaporator’s and some operating records. TABLE
Plarrr
1
C and V
and Skurrih A K.D. __ ._
X.0.
K.V.
K.V.
IO.335
IO.-iC9
1,616
2,6lh
2.616
cost for mtc.c.
11,38-l
13,732
I.216
I.200
1,200
cost (\\‘@rkShoFs)
7,429
1.613
332
331
332
20.971
11,250
6,ooo 4.376 -
6,m 4.376 -
A-.0: hl3intimncc MzaxiJ xltie.
sea water, scale deposits and B gives further data on the show photos and diagrams
Opcratian
\tagcs
uags
Cc*t or PD
22,524 2.109
8
_-
Cost of ferric chloride
I .%I6 1,380
4.376 -
Ccrst of acid fax cluning
1.125
1.125
37s
375
375
Cost of chlorine
8,175
8,175
5.017
3.190
2.100
Cost of clcaicity consumed
11,500
104.200
13,900
Cost of steam consumed
43,800
42.600
36.30
1,300 17.600
12,800
118,000 -
86,claO -
46,200
23,300
27,000
34.500
17,soO
20.250
121.532
60,289
56.003
109.832
48,693
49,253
330
330
Dqreciation
of unit (15 yrs)
Depnxintion
of Unit (23 yts)
Total cost bastd on 15 yrs depreciation Total cost based on 20 yrs dcpre&tion Production in million Imp. gal&car Ctit of 1.000 Imp. %;rlsin Iils on depreciation of 15 years BYeat l
One K.D.
237,341
197.407
-
340
300
290
330
190 -
650 -
368
173
169
336
144
149
.= 1,OtJOfils == S2.8 = El. Dedimrion.
1 (1966) l-100
SlJS!SfAR%-, COSCLUSIOSS
ASD
RECOSlMENDATIONS
1. The multistage sea water flash type evaporator is the most reliable equipment to produce distillate from sea water at reasonable cost and the submerged tube type should be limited to very small plants where a lot of outage is possible. of scale formation is a complicated subjlrt and local conditions (nature of sea water. design conditions, chemical treatment etc.) and hence the writer adv%es that any authority deciding to install a sea water distillation plant cf large capacity should build first a unit of reasonable size and carry out tests on scale formation and chemical treament before committing itself to the full-scale installation required. Kuwait is iucky in that no iron is present in its sea water; in other places presence of iron has caused a lot of trouble with respect to the appropriate dosing with Hagevap and very complicated sludge and scale were formed. Acid treatment is, in the writer’s opinion, the best for large units, especially in countries paying for fuet, provided that reliable pH and dosing controls are applied. 2. The mechanics
are of major importance
specifications when ordering a plant cannot be under the guidance of experts who hate site experience and who appreciate the difference in effort required between receiving the offers and placing the order. Prototype tests in the laboratory or on site are sometimes of great importance and can save a lot of time and money. 3. The importance
underestimated;
of clear-cut
these should !x prepnrcvt
4. Much work still needs to be carried out to reach a practical, drfinitc correlation between size of flash stages and their duties especially for units of large capacity (1 m_rpd and over), and also for brine control. 5. Choice of materials, chemicals and coating is, in the writer’s opinion. the principal factor which leads to savings in capital as well as in maintenance charges.
6.
The
steam water ratio is given for different plants in the heat flow diagrams but in Kuwait this is not the important factor due to free fuel and hence the ratios were chosen for availability of power installation and economy. 7. Flash evaporators are sensitive to variation in sea water temperature, brine temperature and feed inputs and the writer advises that changes should be r&uced to a minimum and the automatically controlled and not to manual equipment should be suitable for easy start up and shut down. 8. The cost of production 1953 and the present.
from sea water distillation
operation.
has fallen rapidly
Dcsulinmiun.
Also
between
1 (1966)
I-100
53
TABLE SE&
._ -. - - _ Total dtswlred solids. m ppm Total allalinity. CKO %,in ppm Chlorides, Ct. in ppm Sufphata, SOI. in ppm Permanent hardnw. CKO?;. in ppm T~aqwrsry hardness. CaCO1. in ppm Total h;lrdncrss. CaCOI, in ppm Calcium. Ca’*. in ppm M3gncG~m. *fg’ +, tn pprn Bromine. Br -, in ppm Silica. Sir&. m ppm w Neutral clcxtri~~t conductivity. mitromhos Maximum sea xwtcc tcmpcraturc Mmimum se3 wtcr trmpcraturc
tat
\VXTFR
!
ANhLYSiS
Siwwaiki~ sitr from Kuwuit &?v -48:200 150 24,800 3.500 7.950 la0 8.050 400 I .ciYo 80 5 5.8 76.iwO 90 F 58 F
PI 10-C
Shrraitvr sitt- from the Arabian Gulf _._. ._ _... ..-._. . -J2,@30 135 23,100 3,IcJO 8.400 100 8,500 500 1,465 SO 5.0 8.3 70,500 95’F 58-F
Srthnrrr.gcd rrthc gpr cwpmz~w.~ Shuwaiih A wrth 2.5 ppm PD.8’ traxtmetlt Shw\aikh B uith 150 ppm ferric chloride and 2.5 ppm PD.Y treatment 2frd &Tr
I ri Cjfjkr
___ MgKii)~ CzlCOJ
.
3rd eflect
B h 0 10 . - 0.0_ _ 0’ ,U 10 n* 0, .a,, -“..-_-._--_ _. _ .__ :\
40.0 49.6
-
7.5 1.3 -
casot
SiU: FczO,
R
X
65.0 15.0
5.5 90.0
75.0 10.5
1.5 5.6 12.5
1.5 3.5 -
I.8 6.8 4.2
41.5 48.2
1.0 5.2 -
B %___ 72.0 4.0
3.5 4.5 15.2
(b) FZadx rope c~npora:urc Shuwai(rh C and D with 5 ppm PD.8 Shuwiiikfi E sith 4 ppm PD.8 trcxmcnt __ . . __. - I - - .“__.__. _-_ Organic matter SiOz Sdublt phosphates Ns,PO+ Xig@D& MgtOII), C&O, CrlCOJ
_ . -_ _ _.-.i-
C urrJ D (P,) _ -. .____..____10.5 6.1 2.5 23.4 40.5 4.8 6.5
Et:.) ._ ..^- ._ ____-8.5 6.5
3.6 22.8 42.3 1.5 4.2
NaCl
5.1
8.0
FC&
Trace
1.2
* See note on page 78. ~~S~~~~~~~, I (1966) l-100
EYAPOR4TOR
----
___
_. ._
__
BRISE
AS4LMIS
Sbuwikh A .__ -.-. MO.ti101,490 9.6 SO 285 ~0.000 6 ,890 16,875 f ,ooo 3.195
_
Conductivity T.D.S. in ppm PH Total c;lusiic ~5 NaOH in ppm Totnl 3.1 kalinily 3s C&O, in ppm Chlorides 3s Cl- in ppm Sulphates as SO:- in ppm Total hardness as COCOJ in ppm Ca!cium 3s cLll+ in ppm Mqqnesium a M& 4 in ppm
APPENDIX
Arca
1st ElfI33 2nd Effect 3rd Effect Condenser
6’1’ 6’1’ 6’1’ 6’1’
2.150 2.150 2,220 1.600
dia. __~_____.____ 1st Effect 2nd Effect 3rd Effect No. 2 Preheater No. 3 Prehtiter Condenser and No. 1 Preheater
9’ 9’ 9’ 22, m 2’2’
6.300 15.615 940 3.320
Etaporaror
114,175 9.5 So 385 58.500 8.150 19.125 1.200 3.920
rt.h.v
Gauqz
1.3.
I’ 1’ 7:s’
IS IS IS
Lrnyrh
2 . Ii’8 I!‘-$; 2 . t1?31j42 . IG’I l/4’ IS’1 7/S’
17 kVA 66.5 LVA
11
EV9PORATOR
: SlIUWAIIil
B PLA?.T
of
/warinK surface fr = . -.-.---. _._ “00 “Cl0 _._ 2.200 200 2Oc 1.700
Es aporafor tubzs h’o. ny ..___ 818 818 S18 S8 88 750
3’8’ 300 Electric load:
9.1 70 310 dS.oco
6.315
i-
-718 -728 540 388
TYPE
Area Shell
180:ooa
94.510
15.000 9:0 3.320
----_I_ ‘V@. off O.D.
TABLE TUBE
I49.cloo
1
Elrxtric load without recirculation Electric load sith recircul;ltion
SL’RUERGEO
143.OCO 90.705 94 a5 ‘775 17.900
of
hrariry surface .fr 1
fira.
Shuwaikh E
Shmaikb Cond D
B
TABLE
ShCll
Slrurmihh B
32
O.D. Length Garrge _- ___-_____ __._ ____ _._._ --..-3:116 14’1 3/v 3j.y 14’1 3X 16 14’1 34’ 314’ 16 1’ 16 8’3 l/1I’ 16 8’3 l;r 3:418 11’10 1/r 3pr 18
4Ci kVA Demfimfiun.
I (1966) 1-z
--
WATER
PRODUCTION TABLE
FLASH
t3 PE EVAPOR
\TOR:
IN KUWAIT
III SilUWAIKt4
Evaporator
surfocc ff-
----.
---. rejection
Hat Hut blat&
-..... sxtion
D PLAhT
of
Area
heaIing
Hmt
C AND
.- _.
A’o. of
O.D.
tubes Gauge
Length
_._. _ _..__________ _ __._..___ .._ _______.._.
Wi.UfL?r velocity inside r&es ftlsec
I
KS00
1.288
7,0x’
18
30’
gain section
3
26.400
3,564
7jP
I23
30’
6.5
input
I
7mo
1 ,mJ
7)s’
IS
28 ‘6’
6.5
1
2,000
?/‘a’
18
sation
up c\;rp. Ektric
lad:
588
6.5
340 kVA
TABLE ITPE
FLASII
IV
E\‘APORATORS SHUN’AIKII
E PL.A?cT tVa:er
Area of ‘VO. 01
hearing surfice /I2
rragrr ___
__- _ . _--
-.
.--.
Hat
rcjcction szction
Heat
tin
Heat
input
E%oporaror rubes so. ofl
_.
section
I6
section
I Elmtric
I4,f.M
1’
0.904’
20’6’
6.5
1,530
1’
0.901
I_(%-
6.5
6.000
1o.d
: 7S kVA
FLAW
TYPE
No. of 3 rages
gin
Hut
input
_-_I_.--_..-._L scmion 3
section
V StiUwAIKII
E\APORATOR
Are0 of hearing
F PUTT
Wafer t efocily
Et aporator tubes
inside tubes fr/sec
SlU,=O-C ff2
Heat
Length
---
TABLE
__-_--__ rcjmion
I.D.
1 77.400
Hat
O.D.
velocity inside rulrsk fi/SCC
x0.
off
O.D.
---_- ----.-----..12,570
I.D.
Length
___.-_-
-
---
4.286
1’
0.90)
20’7 718’
6.5
27
138,780
2-+,lOo
1’
0.9o.r
20’7 718’
6
1
5.155
I.676
1’
0.904*
12’8 718’
7
section Electric
toad:
60 kVA
Desaiimdon.
1 (1966)
l-100
86
hf.
H.
ALI
EL-SAIE
DCSUiiMfiOII,
1 (1966)
l-100
87
._ _ _ ,. .__
, .
.__
_:,_. :
.-
- -- _____ ^ --.
.-_____.
_-
/ .._
c--
-,
-
-
L
-,.c-
.
sT*TION
.
CI
,__^_
e
...a
.. ‘2
y:-
$!+., -.-
.
.
yyzg
I
L
-
‘:
..
-0 , 5 -_
’
.i.,
-
:;2=
__,-p
_I
-
-.
<.‘
..g
,
.:.
__.
. .
e-fE$
STATICN .-.
.
.;
,
;.;
.-..
._
;_
<.i;
J,rtu*~o-4_..
.-__ .
’
&A-L-
_ ____--_ __-
__.+ B
. .
7---‘
c
_;o:_.
*
-.---
.
\
-
i
_A
-----7
-
r?
1
_._-,
- -
P&ES---j,
-
STATON _
_:,__
C _
0
cs3
I . t
1..
-_
;-:
D
_
_.._._ -
_---_-._-
I
i ;
____
7
=
i
_
.
) --_ _.
-1
.-
__
- -
,
*G&s s
‘.
.
_.
z_-_-_r--_ -
i
_‘jz;-:
.
--
:
_.___2_. --.--
J
__._
-
Ye
.
A
<.-“” ._ --- -.s
--I,-._
._
_..
--.
-
__ .
.
I.
__L
.
c__
--f
L_-Yz-Y-~y
-
, I-
, _
j
_..
,__-__
_ ,
--
-
.
-.-l
:_-T-
I
-
, .
-
I_,<_.
, --._?
I7
\-- --L
s---T
C”Y’_.
__.___
._ __ _.
I’
_ _ - I’
Dcsali~arion,
1 (1966)
l-100
M.
H. ALI
EL-SUE
Figure 3 One e\sporaror
on ,C,
L.
Il.-P
-r
SL
Shuwaikh
r
e
--
-
-
-__
_
_ __
A disriilation plant
-_ .--.------ -.-.i-I
&z-a
a-PInu.,,
~..
-.
.:a’.
-%r’
-.
-._
-__.,
. .
_.
.
-
.. ._
. .
i
. ..; ,
OJD,.
Submerged
tube type c\zporator. Shuwikh A plant (Hithcut rccirculztion) density as NaCl. Ratio 2-PD.& Inja-tioo 2.5 ppm
Desafimrion. 1 (1966) I-100
Figure Submcrgcd
5
t&c type c\aporator. ShuHatih A plsnt (with rc-circulation) mnstry as NaCI. Ratto 2-PD.& Injection 1.5 ppm
Figure 6 One evaporator
Shuwaikh
B distilla’.ion plant
Desalination,
1 (1966) l-100
M. H. ALI
H-1 -
EL-SAIE
flow diagram, submerged tube type sea water evaporator. Shuwaikh B plant Specific heat consumption 120 Btu lb of distillate - - - - - Distilhtc s=3 water and brine Swam and condensate
One cvapotxtor
Figure 8 Shuwaikh C and D distillation
plant
WATER
PRODUCriON
IN KUWAIT
Figure 9 Heat flow dugram. Flash type set wdfcr e\apcjratot. Circulation ratio 13.4 - Sfxctfic: heat consumption
Shutiaikh C and D plants 345 Btuiib of distillatc
BRINE ORIFICI EXCHANGE
B .: h
DISTILLATE PUMP SUCTION
BRfNE PUM SUCTfOf
Figure 10 Flash type sea Natet evaporator Shuwaikh Section in A stage
C and D
M. H. ALI EL-SALE
Figure Flasch type e\apo:ator. Tap brine tsmp. 194 F--!knsiiy
II Shu\taikh
as NaCI
ntio
C ,~lant
1.8-PD.8 injection 5 ppm
ZJSO P P H.
4.4a2.750 P P H
FEED
L1 ,.25,000
l CH
BLOW DOWN ‘\834.wo c P ” flO’F
1
!
I
BRINE REC. Pi.Xf
Figure 12 Heat flow. diagram, flash type sea water evaporator. Shuuaikh Circulation ratio ItSpccific
heat consumption
181.75 &u/lb
E plant
of distilatc.
Desulinofion, 1 (1966) l-100
r A t 1
Figure
13
Shuuaikh
E
distillation plant
1 ,
$-------”
1
WEAT EXCHANGE TUBES
0RIF:CE .--. .-_ FOR VENT
/
OIST.
FRO?4
PREVIOUS
_
DISTILLATE
STAGE
--
fz g)-
__..--. .-.__-.
_
ORIFICE p-., ‘-.’
84
--
:1
:’
- ------ _____._:___ ----_----;i
ET
:
.___
:
*f
-
_z:
Figure
_-_
1-t
Flash type sea
BRINE WEIR
water cvaporator Shuwaikh
E
section in A stage
A \;uics 4’-2 10’4
--BRINE ENTRY
from
I
3/4- to 311’
_--. A
_.-_ Desdinufiun,
1 (1966)
I-100
91
VENT ----
--_ A.__ -.-_
DIST.
FROM
PREVtoUS _-
Figure
15
Flash type sea water cvaporalor Shuuaikh F
!
. -=
DlSTlLiATE O!I_FJcE ) - - _:-_, _^._-
-_
STAGE
-
S‘xtion in Astagc A varies from
3’-8’ to 9’ -
PIPE
-i.P
RINE WEI 1 1
6’
Shuwaikh
Figure 16 F distillation
plant
95
WATER PRODCCTfON IN KUWAIT
c
Total distil!atc
Figure 18 water production from Shuwaikh
distillation
plant
Desu/inafion, 1 (1966) l-100