MSF Distillers LifetimeKuwait experience

Ministry of Energy- Electricity and WaterKuwait

March 2006

1. Seawater Desalination Progress In Kuwait:

• KUWAIT has population of 2.2 M people in 2005 .

• The limited sources of fresh water and the geographical position of Kuwait forced

towards the use of seawater desalination as the main sources of drinking water.

• 1953 Kuwait has sea water desalination plant with 0.1 MIGD

0

2

4

6

8

10

12

14

1953

1954

1955

1956

1957

1958

1959

1960

1961

1962

1963

1964

1965

1966

1967

1968

1969

1970

1971

1972

1973

1974

1975

1976

1977

1978

1979

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

Year

Num

ber o

f MSF

Dis

tille

rs• Since desalination was started, a total of 88 distillers are installed in Kuwait with different design and different capacities.

• Recently there are 48 MSF seawater desalination units installed.

Number of MSF distillers installed in kuwait (1953-2004)

0.5 12

6

12.5

0.1

6/7.2

5

0

2

4

6

8

10

12

14

1953

1954

1955

1956

1957

1958

1959

1960

1961

1962

1963

1964

1965

1966

1967

1968

1969

1970

1971

1972

1973

1974

1975

1976

1977

1978

1979

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

Year

Inst

alle

d C

apac

ity p

er U

nit M

IG

Figure (3): MSF Installed Capacity per Unit In Kuwait, MIGD/Unit

The MSF distiller in Kuwait pass through number of development during the five decades Including:

• The capacities of individual units.and others parameters .

• construction material. Such materials include:

1. 316L stainless steel for flash chambers instated of carbon steal.

2. Titanium alloys instated of cupper nickel for tubes.

3 .antiscalants chemicals: polymers as ploymalike, and polyphosphnic, instead

of acid and Shuwaikh mix.

Kuwait Ministry of energy – electricity and water (MOE-E&W) has spent more

than US $ (2.8) Billion until 2005 .

0

500

1000

1500

2000

2500

3000

3500

1956

1958

1960

1962

1964

1966

1968

1970

1972

1974

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

2004

2006

2008

Year

Cos

t Mill

ion

US

$

Figure (1): Accumulated Cost of Installed Desalination Plants in Kuwait (Millions US $)

The MSF distiller unit in service located in five distillation plants:

1. Shuwaikh, 2. Shuaiba South, 3. Doha East, 4. Doha West, 5. Az-Zour South

• Distillation units in Kuwait are multi stage flash (MSF) .

• All these station are dual purposes except Shuwaikh station.

• The total capacity of the distillation stations is 315.6 MIGD.

Table (1): Distillers in service at MOE-E&W.

Station Tech. No. Of Units

Capacity (MIGD)TOTAL

Shuaiba South power generation and water desalination plant. MSF 6 30

42

18

110.4

115.2

315.6

Doha East power generation and water desalination plant. MSF 7

Shuwaikh distillation plant. MSF 3

Doha West power generation and water desalination plant. MSF 16

Az-Zour south power generation and water desalination plant. MSF 16

Total - 48

315.6 MIGD

0

50

100

150

200

250

300

350

1953

1955

1957

1959

1961

1963

1965

1967

1969

1971

1973

1975

1977

1979

1981

1983

1985

1987

1989

1991

1993

1995

1997

1999

2001

2003

Year

Dis

tilla

te P

rodu

ctio

n

Total Capacity For MSF Distillers In Kuwait (MIGD)

0.1MIGD

2. DISTILLER LIFETIME :

• the capital investment depreciation was calculated accordingly the lifetime.

• In the past, the normal lifetime of distiller is 10-15 years.

• Recently The maximum lifetime of MSF is 20-25 years.

• In KUWAIT the oldest unit still in service, has been over 33 years .

Table (2): Distillers Commission Year

Station Units Age (years)

Running Hours

A1,A2,A3,A4 33

A5, A6 3142284

53325

11080

115894

120611

A1,A2,A3 28A4,A5,A6,A7 27

Shuwaikh distillation plant D1,D2,D3 24D1A,D1B 23

D3A,D3B,D4A,D4B,D5A, 22D5B,D6A,D6B,D8A 21

D7A,D7B,D8B 18D1,D2,D3,D4,D7,D8 19

D5,D6 8D9,D10,D11,D12 5

Az-Zour south power generation and water

desalination plant

Doha West power generation and water desalination plant

Doha East power generation and water desalination plant

Shuaiba South power generation and water

desalination plant

Shuwaikh distillation plant

Unit No. Running Hours

D1 2837

D2 4866

D3 3377

Unit No. Running Hours

A1 4423

A2 7691

A3 5695

A4 6313

A5 7117

A6 7744

Shuaiba South power generation and water desalination plant

Doha East power generation and water desalination plant

Unit No. Running Hours

A1 6529

A2 6756

A3 7310

A6 7895

A4 7745

A5 8443

A7 8647

Doha West power generation and water desalination plant

Unit No. Running Hours

D1A 6378

6640

7623

8009

5760

D3B 7424 D7B 6441

D4A 7600 D8A 7961

8639

D1B

D2A

D2B

D3A

D4B

Unit No. Running Hours

D5A 8284

D5B 8354

D6A 6348

D8B 7793

D6B 6058

D7A 6582

Az-Zour South power generation and water desalination plant

Unit No. Running Hours

D1 8120

8014

7794

7386

7599

D6 7676 D14 7584

D7 7005 D15 6759

7826

D2

D3

D4

D5

D8

Unit No. Running Hours

D9 7309

D10 7274

D11 7022

D16 7795

D12 7696

D13 7751

10-20 years17%

less than 10 years17%

more than 30 years13%

21-30 years53%

3.FACTORS EXTENDED MSF DISTILLER LIFETIME:

• Design :

Distiller design is the first step to attend very high reliability and availability for the unit. The special design features of the MSF distillation in Kuwait will meet distillers performance guarantees and it will provide adequate service during the life of the plant and allow for flexibility in operation.

• Operation :

Good Controlling of operation parameter will adequate corrosion allowance and scale formation were higher efficiency is attaining. Feed water salinity, temperatures, production will consider on operation mode. With different conditions operation should be according to the manufacture instructions.

• Maintenance :

Maintenance included cleaning, repairing, painting, welding, rubber lining . for all part of distiller as heat exchanger tubes, water boxes, flash chambers, instruments, pipelines, pumps, compressors . Distiller maintenance is divided into two parts Programmed Maintenance and Emergency Maintenance.

Case - Study

4.Shuaiba south distillation plant Rehabetation project:

•Shuaibia south distillation plant consist of six distillers commissioned during 1972-1975

•To extended distillers life, a Rehabetation project for all units carried out on 24 October 2005 and planed to be finished within three years.

:

section Main item

Distiller outer shell Remove all cladding and insulation, inspection, replace the roofplates and insulation, sand blast the entire external surface , apply epoxy.

Water boxes and brine heater Replace heat rejection water boxes, inspect heat gain section WB, sand blasting for internal and external surfaces, painting, replace all tubes for brine heater and stage 1-2-3-23-24-25, (titanium for HRS & brine heater),(ALBrass & Cu-Ni for HGS), hydrojet clean and acid for others, replace insulation.

Distiller internal Replace the demisters, inspection, blasting internal surfaces, replace the corroded floor and division plates where thickness reduction 25%, replace distillate trough for unit(5&6), painting.

Pipes and filters Replace seawater inlet,outlet and recirculation pipes,(stainless steel 316L), fix high performance stainless steel 316L debris filter, inspection pipes, painting, sandblasting, renew cooling water system, replace insulation. Renew all supports for lines.

pumps Redesign and modify lubricating system, replace condensate pump set, distillate pump, complete overhaul remaining pumps, civil work for foundation.

ejectors Retube all ejector condensers for A1with titanium tubes.

Control valves Replace the pneumatic control valves with its actuators.

Motorized valves Replace the motorized valves with new ones.

Chemical injection system Supply & installed pumps and agitators, design fabricate supply and install two interconnected carbon steel rubber lined, replace all half inch pipes.

Steel structure and civil work Inspection, modify the bottom walkway structure, repair the concrete foundation

COMMENTS:

• A - Sea water desalination is the main sources of fresh water in KUWAIT

B - Multi stage flash MSF in KUWAIT has developmed and greatly improved overfifty years .

C - Good design , operational and maintenance run the distillers smoothly andextend their life time.

D - For running units , decision need to continue run the units with modification toincrease their life times and improve the effeciency , or to shut down and buildnew desalination plants with longer life times .

• E - To cover the demand for water in the future, Kuwait will have to:

•Continue the program of inspection and maintenance for all distillers.•Construct new desalination plant.•Continue water conservation programmes.