Design of drinking water treatment plants

Transcriptie

1 Design of drinking water treatment plants Prof. ir. Hans van Dijk April 13, Afdeling Watermanagement Sectie Gezondheidstechniek

2 Contents 1. Capacity 2. Process scheme 3. Hydraulic line scheme 4. Main water flow scheme 5. Lay-out of site and buildings 6. Cross sections 7. Hydraulics 2

3 Drinking water from tap to source Relationship water supply is upstream: Production Transport Storage Distribution Water use Transport pumps Distribution pumps Q Catchment Treatment Transport pipes Reservoir 0 24 h distribution area Water use water users, fluctuating demand in distribution area Distribution supply to different water users, maintain pressure Storage buffer between production/transport and distribution Transport smooth transport of water Production catchment and treatment, steady production 3

4 Capacity versus water demand in time capacity gross demand over capacity net demand reserve time 4

5 Fluctuations - Events Events in water use period more years year week day hour typical cause dry summers watering of the garden in summer Monday=washing day, Sunday= day off almost no demand during the night half-time soccer game All events may occur at the same time! 5

6 Fluctuations - Events Water consumption [m 3 /h] Water use Enschede, saterday July 4th 1998 Argentinië - Nederland evaluation e half 2 e half rest Time [h] End of game 6

7 Variation in water consumption Dry/wet year +8/-6% of the average consumption Summer/winter +7/-6% of the average half year consumption max/min month consumption +10/-8% of the year consumption/12 max/min week consumption +25/-30% of the year consumption/52 max/min day consumption +40/-35% of the year consumption/365 max/min hour consumption +80/-75% of the day consumption/24 max/min minute consumption +85/-75% of the day consumption/1440 weekday/sunday +10/-25% van de weekconsumptie/7 7

8 1. Design capacity average capacity (m 3 /h): Q j = year capacity/(365 24) Average capacity on a maximum day in a dry year Q d = Q j = 1.5 Q j Capacity on a maximum hour on a maximum day in a dry year Q u = Q j = 2.7 Q j for catchment, treatment and transport for distribution pumps and pipes Q d Q u Production Transport Storage Distribution Transport pumps Distribution pumps Q Water consumption Catchment Treatment Transport pipe Reservoir Q d Q u 0 24 h Ditribution area 8

9 2. Process scheme What is the raw water composition? What are the requirements of drinking water? Drinking water law Drinking water standard EG-guidelines VEWIN-guidelines WHO-guidelines USEPA-guidelines Guide lines Protection Water companies Which process scheme is good? 9

10 Process scheme 10

11 Process scheme Experience of comparable treatment plants Pilot plant research Reliability and robustness Quality raw water and clear water 11

12 Process Scheme softening Where? Which process? abstraction cascades RSF Tower aeration RSF Clean water storage 12

13 3. Hydraulic line scheme 13

14 Hydraulisch lijnschema 14

15 Hydraulic line scheme Foundation depth Maximum building height Pump phase Head loss per treatment step Head loss in pipes Upstream- from the tap to the sources 15

16 4. Main water flow scheme 16

17 Main water flow scheme Number of streets Reliability water production Costs Flow splitting equal flow pattern Clear lay out Maintenance Plant operation/connections 17

18 5. Lay out 18

19 Lay out Clear and logical lay out Compact building Accessibility Architecture Structural design 19

20 6. Cross sections 20

21 Cross sections Ordering of pipes Accessibility Logical lay out 21

22 7. Hydraulics Calculations of hydraulic losses Equal flow division of water over process units Economical diameter pipes (v = 1 m/s) 22

23 Hydraulics or Controllers? Q 1/4 Q 1/4 Q 1/4 Q 1/4 Q Q FIC FIC FIC FIC 1/4 Q 1/4 Q 1/4 Q 1/4 Q Flow splitting over streets ΔH Filter control (compensation for increased resistance) 23

24 Architecture 24

25 Photo Welschap 25

26 Architectuur 26

27 Disciplines 1. Process technologie 2. Civil engineering Hydrology Structural engineering Geotechnical engineering Material science Landscaping 3. Mechanical engineering Electrical engineering Heating and ventilation Control and instrumentation 4. Architecture 27

28 Project phases RVOI (Regeling Verhouding Opdrachtgever/Ingenieursbureau) 1. Preliminary investigations 2. Preliminary design 3. Final design 4. Tender documents 5. Contracting 6. Detailed engineering 7. Supervision of construction 8. Completion and take-over 9. Operation and guarantee period 28

29 Project phases Nauwkeurigheid Kosten aanpassingen onzekerheid [%] onzekerheid [%] ps sd pd dd los pc 0 ps sd pd dd los pc Veranderbaarheid Planbaarheid onzekerheid [%] uncertainty [%] ps sd pd dd los pc 0 ps sd pd dd los pc 29

30 Voorontwerp 1. Uitgangspunten en probleembeschrijving 2. Schema s processchema hydraulische lijn schema hoofdwaterloopschema geografisch overzichtschema 3. Voorontwerp gebouwen terreintekeningen plattegronden langsdoorsneden dwarsdoorsneden 4. Begrotingen 30

31 Aanbesteding 1. Normaal werk met volledig bestek, normale kwaliteit, normale levertijd openbare aanbesteding 2. Werk met volledig bestek, bijzondere eisen aan kwaliteit van levertijd openbare aanbesteding met classificatie onderhandse aanbesteding 3. Normaal werk zonder gedetailleerd bestek onderhandse aanbesteding, detaillering in bouwteam turn-key 4. Werk zonder bestek, bijzondere eisen aan kwaliteit van levertijd selectie volgens examen procedure, detaillering in bouwteam turn-key Verrekening 1. lump-sum 2. meer- minderwerk (openbare begroting 3. regie (verrekenbaar plus winst) 31

32 32

33 Basis opzet Heel 33

34 Koppelnet met grondwater 34

35 Tijdspad Geschiedenis WPH: 1972: Eerste structuurschema drink- en industriewatervoorziening : Spaarbekken Panheel, inrichting en effecten 1994: Toetsingskader grondwateronttrekkingen en alternatieven 1994: Integraalplan Spaarbekken Panheel 1996: MER gereed 1998: Start bouw Waterproductiebedrijf Heel Start boren puttenveld Start bouw productiebedrijf bouw testen inbedrijfstellen Start aanleg innamewerk en -leiding Oplevering en start productie 35

36 WATERPRODUCTIEBEDRIJF HEEL 20 miljoen kubieke meter per jaar 36

37 Processchema 37

38 WPH - hydraulische lijn 38

39 Hoofdwaterloopschema 39

40 Hoofdwaterloopschema 40

41 Architectuur 41

42 Cascade 42

43 Voorfilters 43

44 Zuiver drinkwater voor Limburg WML investeert in unieke combinatie van oppervlaktewater èn grondwater! 44

45 Eindresultaat 45

46 Next week Overall problem definition Design capacity Process scheme of the existing process Several process schemes Discuss the choice of the process Discuss the choice of the location in the treatment scheme Discuss the use of chemicals if needed 46