Post on 04-Apr-2018
7/29/2019 Design of Pumping stations
1/134
Designing
flooD pumping
stations
7/29/2019 Design of Pumping stations
2/134
WelcomeWhen disaster strikes, a poorly designed pumping station is practically
useless. However, we never learn until its too late.
The medias are ull o examples o poor pumping station design and the
tragic consequences o it, including the tsunamis in Asia and Hurricanes
on USAs east coast.
Today, ooding is the most common cause o disaster in the world and
by ar the astest growing and with it ollows the need or properly
designed and reliable pumping stations.
Based on our expertise within pump solutions, this handbook ofers
guidelines and recommendations to reliable pumping station design that
will protect or limit damages to people and inrastructure.
We hope you will use the handbook in your work with pumping station
design. For additional inormation or assistance, please contract your local
Grundos sales representative or the Grundos Water Utility Competence
Centres.
Jim Rise, Sales Development Manager, Flood Control
Mick Eriksen, Application Manager,
Grundfos Global Water Utility Centre, Copenhagen
Copyright Grundos, 2013, 1st issue
7/29/2019 Design of Pumping stations
3/134
Contents
1. Introduction
1.1 Introduction to Grundos 4
1.2 Introduction to ooding 7
1.3 Introduction to ood control 8
2. The sources o ooding - and the solutions 10
2.1 Can we prevent ooding? 11
2.1.1 Flood management 12
2.1.2 The ood risk cycle 12
2.2 The sources o ooding 14
2.3 Flood control solutions 16
2.3.1 Drain/rain water station 17
2.3.2 Network pumping station 17
2.3.3 Main pumping station 18
2.3.4 Stormwater tank with installations 182.3.5 Pump gate pumping station 19
2.3.6 Flood control pumping station 19
2.3.7 Grundos Remote Management System 20
2.4 Flooding, then what? 20
2.4.1 Water-borne illnesses and water contamination 20
2.4.2 Drainage pumps and service trucks 21
2.4.3 Filtering and disinection 21
3 Designing a ood control pumping station 22
3.1 General considerations 23
3.1.1 Design sequence 24
3.2 Design conditions 25
3.2.1 Flow patterns and boundary geometry 26
3.2.2 Types o installation 26
3.2.3 Water ow (Q) 28
3.2.4 Head (H) 28
3.2.5 Net Positive Suction Head (NPSH) 29
7/29/2019 Design of Pumping stations
4/134
Contents
3.2.6 Water velocity 31
3.2.7 Power supply and backup 31
3.2.8 Trash racks and screens 32
3.2.9 Handling sludge 33
3.3 Pump selection 34
3.3.1 Axial ow propeller pump or mixed ow pump? 34
3.3.2 Number o pumps 36
3.3.3 Pump selection / determine column diameter 37
3.3.4 Minimum submergence (S) 38
3.3.5 Turbulence Optimiser 42
3.3.6 Sensors in the pumps 43
3.4 Dimensioning the pumping station 45
3.4.1 Terminology and conventions 45
3.4.2 Dierent station layouts 46
3.4.3 Pump bay design 47
3.4.4 Pumping station dimensions 50
3.5 Duty strategy reducing minimum water level 53
3.5.1 Grundos dedicated controls 55
3.5.2 Communication modules SCADA implementation 55
3.5.3 Grundos Remote Management (GRM) 56
3.5.4 Motor Protection (MP204) 57
3.5.5 Variable requency drives (CUE) 58
3.5.6 Sot starters 58
3.6 Other considerations or the construction 59
3.6.1 Support beams and columns or the building 59
4 CFD and model testing 60
4.1 Computational Fluid Dynamics (CFD) 61
4.2 Model testing 63
5 Vortex and how to prevent it 64
5.1 Types o vortices 65
designing flood pumping stations
7/29/2019 Design of Pumping stations
5/134
5.2 How to prevent vortices 66
5.2.1 Sub surace vortices 66
5.2.2 Submerged vortices 67
5.2.3 Air-entraining vortices 68
5.3 Retrotting FSI, Formed Suction intake 69
5.4 Retrotting back-wall and oor splitters 69
5.5 Reducing surace vortex by retrotting a bae 69
6 Accessories 70
6.1 Column pipe 71
6.2 Anti-cavitation cone 71
6.3 Splitters 72
6.4 Cable entry 72
6.5 Cable support system 73
6.6 Monitoring unit 75
6.7 Formed suction intake (FSI) 75
7. Grundos service and solutions 76
8. Glossary 80
9. Appendices 84
Appendix : Head loss calculations 85
Appendix 2: Grundos products 102
Appendix 3: List o reerences 118
Appendix 4: Lloyd certicate 128
Th g at th k a gal gl that t jt al t G
a lt. H, G at a lalt G t ag t
th at.
Contents
7/29/2019 Design of Pumping stations
6/134
1. intRoDuCtion
1
Who is this handbook or?
This book is intended to assist application engineers,designers, planners and users o sewage and storm watersystems to incorporate axial and mixed ow pumps.
The guidelines in this book and especially the pumpingstation design can be used as they are, or be adapted to
specic requirements and guidelines.
designing flood pumping stations
7/29/2019 Design of Pumping stations
7/134
Additional inormation
I you need additional inormation that does not specically concern ood pumping station design, perhaps the ollowing
Grundos publications can be o help:
You can nd all Grundos publications in WebCAPS at .g.
Based on the ANSI standard
Grundos Chicago (ormerly Yeomans Chicago Corp.) was
on the ANSI standard working committee or the American
standard or pump intake design. Thereore, many o the
guidelines and recommendations in this book are based on
the design standards o the American National Standards
Institute (ANSI) that Grundos helped dene.
Grundos Water Utility specialists
Grundos specialists rom our Water Utility Competence
Centres, local Grundos sales engineers, and our online
publications are at your disposal and available to oer
whatever assistance you need.
3introduction
t f v r i r f r v n
i ct r m m r
P um pe V en ti l S to pv en ti l a no me te r
Tdamp
[C] [1 5 ] [ k/ m3] [1 -6m2/]
. 11 1 . 1 . 2
. 1 3 1 . 1 .
1 . 1 2 2 . 1 .3
2 . 2 3 3 . 2 1 .
2 . 3 1 . 1 . 3
3 . 2 1 . . 1
. 3 2 .3 .
.1233 .1 .
. 1 2 3 . 2 .
. 31 1 2 . . 1 3
. 3 1 . . 3
. 1 . 2 . 32
1 1 . 1 3 2 . 2 .2
1 1 1. 3 2 . . 2
1 2 1. 3 3 . . 2
1 3 2 . 1 3 2 3 . . 2 2
1 3 . 1 3 2 . . 2 12
1 . 1 . .1
1 . 1 . .1
Varmeveksler
i n r n i l i u r f un t i nT hi nk in h m k i t i l
I n n v t i n i t h n c
. r u n f . c m
Centrifugalpumpen
GRUNDFOS
RESEARCHAND TECHNOLOGY
9
65
7
966
2
04
0
5\
Corporate
Branding
4309
ii l
=
=
=
il i
=
=
=
k l r in l v
rsi - sl .i 1 27- 2-2 1 :57:
GRUNDFOS waStewater
StORmwateR taNkS
DeSign of Stormwater tankSRecommendationsandlayout
7/29/2019 Design of Pumping stations
8/134
1.1 Introduction to Grundos
Grundos is the worlds largest pump manuacturer and a ull line supplier
o pump solutions within water supply, wastewater, buildings services, and
industry.
With Grundos companies in more than countries and more than
Grundos partners, we oer local expertise and support wherever you are.
We support the planning, designing and commissioning o pumping systems,
and we deliver the technology that can meet our customers objectives.
Experts in ood control
With our innovative and reliable ood control solutions we can go urther
than most to prevent ooding in a nancially and environmentally sustain-
able way. Our insight can be applied to addressing the key issues o sae-
guarding people, crops, business and the entire inrastructure.
Over the years Grundos has pioneered numerous innovations that have
become or are becoming industry standards. And we will continue to be at
the oreront in promoting and acilitating energy eciency and sustainable
technology.
It is these innovations that will enable us to meet uture challenges, higherdemand and stricter regulations within ood control. Our commitment is
to play a strong part in the bigger picture, to prevent ooding or reduce the
consequences o it. People worldwide depend on it.
1 designing flood pumping stations
7/29/2019 Design of Pumping stations
9/134
Grundos ood control installations worldwide
5introduction
7/29/2019 Design of Pumping stations
10/134
Source: UNISDR
designing flood pumping stations1
7/29/2019 Design of Pumping stations
11/134
introduction 7
Flooding is not just the most common cause o disaster in
the world; it is also by ar the astest growing.
However, not all oods are alike. Some oods develop slowly,
while others, such a ash oods, can develop in just a ew
minutes even without visible signs o rain. Some oods are
local, impacting a neighbourhood or community; others are
very large, aecting entire river basins and multiple countries.
Inland ooding is the most common type o ooding event.
It typically occurs when waterways such as rivers or streams
overow their banks either as a result o slow ooding due to
sustained heavy precipitation like monsoons or snow melt.
Unexpected oods
But ooding can also hit where you dont expect it at all.
Unusual weather patterns can and do cause unexpected
storms and heavy rains in regions where historical data
has oered no warning. Recent years have provided many
examples o such unexpected oods in both Europe and Asia.
Coastal oods are also very common as a result o high tides
ater storms and increased sea water levels may occur quickly
as a result o storms, hurricanes or even a tsunami.
Afected regionsRegions all over the world are aected by ooding. However,
or countries with large overpopulated cities the consequen-
ces are the worst.
Major cities in Europe, the USA, and Asia, including Kuala
Lumpur, Jakarta, Bangkok, and Shanghai, all have ooding
problems. Indeed, any region aced with high annual rainalls,
increased populations, and expanding cities will be called upon
to place increasingly great ocus on ood control in cities.
1.2 Introduction to ooding
7/29/2019 Design of Pumping stations
12/134
Common to all oods is that they cause catastrophic
conditions or all people and animals aected by theooding. Firstly, there is the physical damage o the
inrastructure to actual casualties both to humans and
livestock. Secondly, there is the contamination o the
drinking water which can lead to diseases and the loss
o crops and ood supply.
Due to climate changes and an increase in the popula-
tion and urbanisation the amount o ood scenarios has
increased over the past decades and at the same time
the population has also become more vulnerable due to
an increased settlement in low-lying areas and near riverdeltas.
Counteracting ooding
Basic methods o ood control have been practiced since
ancient times: reorestation, dikes, reservoirs and ood-
ways (i.e. articial channels that divert oodwater). These
days, oodways are oten built to carry oodwater into
reservoirs where excess water is pumped into rivers.
With this handbook, we wish to use our expertise and
experience to provide valuable design tips in connection
with the considerations o designing new pumpingstations or ood control.
We hope that the simple yet very important consider-
ations when designing ood control solutions will benet
millions o people living in exposed areas all over the
world.
1.3 Introduction to ood control
1 designing flood pumping stations
7/29/2019 Design of Pumping stations
13/134
Flood control strategies usually cover the whole city.
In practical terms, the solutions typically involve mul-tiple pumping stations at several locations to ensure
sucient ood management when nature bares its
teeth.
However, the decision to implement a ood control
strategy is oten made when it is too late: when a
ood has already happened, trailing major damage
in its wake. In some cases, even a wake-up call o
this kind is not sucient; the ood is orgotten until,
several years later, another incident occurs.
Flood control projects very easily become political
bones o contention. There are, o course, nancial
and practical issues to be considered, and it will be
tempting to ocus on immediate problems rather
than hypothetical disasters.
Even so, authorities should view ood protection as a
vital aspect o ensuring a sae environment or every-
one. Ultimately, lives can be at stake.
Thinking ahead
introduction 9
7/29/2019 Design of Pumping stations
14/134
the souRCes
of flooDing anD
the solutions
2 designing flood pumping stations
7/29/2019 Design of Pumping stations
15/134
History has repeatedly shown that there is no
ultimate solution to orestall and prevent ooding
and ully secure people, livestock and inrastruc-
ture.
Every year, nature and a changing climate set new
records or the size o storms, rainall intensity
and tsunamis. This causes increasingly intense
episodes and oten in unpredictable geographical
areas.
We cannot create a complete guard against these
phenomena, but with the experience and know-
ledge gained rom each episode, we can constantly
improve our ability to withstand ooding. We can
minimise the risk or populations and livestock,and with our ability to handle the situation beore,
during and ater ooding, we can limit the damage
to inrastructure.
the sources of flooding and the solutions 11
2.1 Can we prevent ooding?
7/29/2019 Design of Pumping stations
16/134
.. Flood management
In an eort to address ooding, we will use the EU
ood directive or inspiration. It identies all the
actors that should be taken into account and pro-
vides clear requirements or individual countries:
Preliminaryoodriskassessment. Floodhazardandriskmapping.
Floodriskmanagement.
Cooperation across borders
In this context, it is perhaps also important to
understand that ooding knows o no borders as
waterways and shorelines are coherent. Flooding
is a common problem and must be solved in coop-
eration across borders.
We start where nature stops
As a pump manuacturer, our contribution to the
above relates primarily to ood risk management.
Through new technology, constant product deve-
lopment, services and solutions, we continuously
seek to meet the changing needs o the market
and our customers. In terms o ood control: Westart where nature stops.
.. The ood risk cycle
The concept o ood risk management is bulky and
can hardly be regarded a stationary nature. Rather
it is more like a cycle that continues to evolve.
To cover all elements, we use the ollowing cycle to
describe the concept.
2
Post ood measures
relie
cleaning
reconstruction
organisational
and nancial aid
Preventive ood risk management
spatial planning
ood deence
retention
preparedness
insurance
Flood event management
early warning
reservoir control
evacuation
rescue
designing flood pumping stations
7/29/2019 Design of Pumping stations
17/134
Preventive ood risk management
Our contribution to ood deence extends rom household
solutions to large scale management o water ows:
Householddrainagepumpingstationsandstormwater
solutions.
Networkpumpingstationshandlerainwaterinscatteredsettlements and urban areas.
Mainpumpingstationsinrainwatersystemswith
associated stormwater basins
Megastationsforhandlingwaterowsintributariesto
larger rivers and outlet to the recipient or the sea.
Supportingthedesignandprojectmanagementduring
the planning and execution and commissioning o systems
and solutions.
Flood event management
Grundos has developed operational solutions and servicesto handle ooding and improve reliability. These include:
Operationofinstallations.
Conceptsforservice,preventivemaintenanceand
preparedness or existing installations.
Controlandmonitoringconceptsformonitoring
the status and alarm unctions.
Post-ood measures
Immediately ater a ood, a community aces great
challenges. The population is at risk, as drinking water
supplies may be inected. To get the inrastructure backon track, sewage must be removed and entire areas
cleaned up.
Pumppreparednessforpumpingofexcesswater
portable pump solutions
Stationaryandmobiledisinfectionsolutionstomaintain
a drinking water supply.
13the sources of flooding and the solutions
7/29/2019 Design of Pumping stations
18/134
Pump gate
2.3.5
Service
7.0
Main pumping station
2.3.3
2.2 The sources o ooding
2 designing flood pumping stations
7/29/2019 Design of Pumping stations
19/134
Network pumping station
2.3.2
Wastewater treatment plant
Rainwater collecting system
Drain2.3.1Stormwater tank
2.3.4
There are as many causes o ooding as there are natural phenomena. However, others
are man-made causes that increase the risk o ooding, triggered by the way we establish
and organise our society.
Examples o settlements in high-risk areas
and urban areas.
15the sources of flooding and the solutions
7/29/2019 Design of Pumping stations
20/134
Despite the many causes, we will break down
ooding occurrences into the ollowing:
. Inland ooding
Primarily related to precipitation, either prolonged
rain or intense local rain. Depending on the geo-
graphical location, it can also be precipitation inthe orm o snow and accelerated melting.
. In deltas
Where rivers or waterways meet, bottlenecks
develop and block the water ow towards the
recipient or the sea.
. In coastal areas
Hurricanes and climate change can cause elevated
water levels with the risk o ooding rom the sea
which can also be caused by undersea earth-quakes ollowed by tsunamis.
Regardless o the source, a ooding threat is virtu-
ally always a combination o these sources.
Oten heavy inland rainall and elevated sea levels
are connected, and elevated sea levels will aect
inland river ows.
2.3 Flood control solutions
Grundos oers a wide range o ood control solu-
tions rom small solutions or private households
to large-scale solutions that protect mega cities.
In the ollowing, we will introduce some o the
most common solutions and their natural applica-
tions.
2 designing flood pumping stations
RAINFALL
STORM SURGE
EARTHQUAKE
FLASH FLOODS
INLAND
ESTU
ARY
COAST
RIVER FLOODS
COASTALFLOODS
TSUNAMIS
DISCHARGE
DISCHARGE
WATER LEVEL& WAVES
WAVES
KEY FACTORSTIME
RAINFALL
7/29/2019 Design of Pumping stations
21/134
2.3.1 Drain/rain water station
Application
Excess water is collected in the well and pumped awa romthe house.
Grundos solution: We oer solutions with integrated control
and external control as complete units with inlet and outlet,
and as single components.
Flow: - l/s
Head: m
Benets
Saet: Surveillance and alarm
Reliabilit
Products
Pumping stations: PUST
Pumps: AP/KP/CC/DP/DWK/EF/DW/ AUTOADAPT
www.grundos.com/food-control
2.3.2 Network pumping station
Application
Collects and distributes
rainwater and storm-
water.
Flow: - l/s
Head: m
Benets
Flexible extension -> less piping and gravitation -> reduced
depth o main pumping station
Intelligent control between pumping stations
Combined with stormwater tanks
Surveillance and alarm
Products
Available as pre-abricated units or customised solutions
adapted to the existing inrastructure.
Pumping stations: PUST
Pumps: SE/SL/S/DPK/DWK/ AUTOADAPT
Drives: CUE
Monitoring: GRM
Controls: LC/LCD/DC
Accessories: Pipes/valves
www.grundos.com/food-control
17the sources of flooding and the solutions
7/29/2019 Design of Pumping stations
22/134
2.3.3 Main pumping station
Application
Receives rainwater rom pumping stations and gravitation
sstems. Capable o handling large amounts o rainwater
and distributing it in large pipe sstems.
Flow: -, l/s
Head: m
Benets
Independent o gravit -> reduced construction costs
Intelligent control in combination with network pumping
stations, stormwater tanks and other pumping stations
Minimising the environmental and human consequences
o overow
Products
Submersible or dr installed pumps: SE/SL/S/ AUTOADAPT
Controls: LC/LCD/DCDrives: CUE
Mixers: AMG/AMD
Monitoring: GRM
Accessories: Pipes/valves
www.grundos.com/food-control
2.3.4 Stormwater tank with installations
Application
The concept o storm water detention is to temporaril store
excess storm water runo. This is to avoid hdraulic overload
o the sewer sstem, which could result in the ooding o
roads and buildings with untreated wastewater or its release
directl into the environment, causing pollution.
Flow: - l/s
Head: m
Benets
Reducing peak ow and equalising ow rates
Better utilisation o the existing sewer sstem
Allowing or intelligent management o stormwater ows
Savings on inrastructural investments
Products
Pumps: SE/SL/S/Flushjet/ AUTOADAPTControls: LC/LCD/DC
Drives: CUE
Mixers: AMG/AFG/AMD
Monitoring: GRM
Accessories: Pipes/valves
www.grundos.com/food-control
2 designing flood pumping stations
7/29/2019 Design of Pumping stations
23/134
2.3.5 Pump gate pumping station
Application
Pump gates ma be
a reliable option i
a pumping station
and reservoir arenot an option due to
lack o space. I the
outside water level is
low, the pump gates
and screen will be
open and discharge the inside water b gravit ow. Once
the outside water level gets higher, blocking the back ow,
the pump gates close and block the rising water level. I the
inside water reaches a certain level, the pump and screen will
start operating to orcibl discharge the water inside.
Once the outside water goes down to a certain water level,the ood gate and screen open and discharge the inside
water b gravit ow.
Flow: -, l/s
Head: m
Benets
Serves as a ood gate and pump simultaneousl
Equipped with submersible pumps, the gates can be
installed on an existing waterwa. Ma in some cases
eliminate the need or a reservoir and pumping station
Products
Pump gates
Pumps: KPL/KWM
Drives: CUE
Monitoring: GRM
Accessories: Pipes/valves
www.grundos.com/food-control
2.3.6 Flood control pumping station
Application
A ood control pumping station manages extremel large
amounts o water owing in open canals at low heads. This
solution demands a good inrastructure because o the large
inlet channels or pump sumps. Also, the power suppl comes
rom a power plant, a dedicated power structure, or a combi-
nation o them.
Flow: -, l/s
Head: m
Benets
Tpicall low operating hours -> high reliabilit
Protects large areas rom ooding
Allows or settlements in areas that are exposed due to
climate changes
With or without water gate to the sea
Products
Pumps: KPL/KWM
Accessories: Pipes/valves
Drives: CUE
Monitoring: GRM
www.grundos.com/food-control
19the sources of flooding and the solutions
7/29/2019 Design of Pumping stations
24/134
2.3.7 Grundos Remote Management System
ApplicationGrundos Remote Manage-
ment is a secure, internet-
based sstem or monitoring
and managing pump installa-
tions in commercial build-
ings, water suppl networks,
wastewater plants, etc.
Pumps, sensors, meters and Grundos pump controllers are
connected to a CIU (GPRS Datalogger). Data can be ac-
cessed rom an Internet PC, providing a unique overview o
our sstem. I sensor thresholds are crossed or a pump orcontroller reports an alarm, an SMS will instantl be dis-
patched to the person on dut.
Features and benets
Completestatusoverviewoftheentiresystemyou
manage
Livemonitoring,analysisandadjustmentsfromthe
comort o our oce
Trendsandreports
PlanwhoreceivesSMSalarmswitheasy-to-useweekly
schedules Planserviceandmaintenancebasedonactualoperating
data
Sharesystemdocumentationonlinewithallrelevant
personnel
2
2.4 Flooding then what?
The solutions presented so ar have all been preventive. In
other words, they have been designed to prevent ooding
completely. However, i a ood occurs, either due to the
absence o a suitable solution or because the weather
phenomenon was so extreme that a ood was unavoid-able, there are also several solutions to minimise the
consequences o it.
2.4.1 Water-borne illnesses and water contamination
During a ood we hear about the deaths, displacements,
economic losses, and causes associated with the ood.
Less common immediately ater a ood event, however, is
attention to water-borne illnesses and water contamination.
Depending on location and sanitation conditions, inec-
tious diseases are oten spread through contaminateddrinking-water supplies. This includes:
Floodwatercancontaminatedrinking-watersupplies,
such as surace water, groundwater, and distribution
systems.
Groundwaterwellscanberendereduselessfromin-
undation o water laced with toxins, chemicals, animal
carcasses, septic seepage, and municipal sewage.
Surfacewatersourcesareimpactedinsimilarmanners.
To reduce the consequences o an actual ood, it is vital to
have emergency systems ready to take over when disasterstrikes. And immediate access to clean drinking water is
essential to prevent a dangerous sanitation situation that
oten exceeds the consequences o the actual ood.
To secure clean drinking water supplies during and ater a
ood, Grundos oers a wide range o solutions tailored to
the specic situation and location.
designing flood pumping stations
7/29/2019 Design of Pumping stations
25/134
2.4.2 Drainage pumps and service trucks
Application
The Grundos drainage solution ranges rom small portable
drainage pumps or private housing, arms and small indu-
stries to large-scale drainage solutions or drainage o areas.
Despite their dierence in size and application, the have all
been designed or pumping drain water and are thereore
ideal or ood-relie applications.
Flow: - l/s
Head: m
Benets
Portable/movable
Plug and pump solutions
Eas to get to inaccessible disaster areas
Products
Pumps: Unilit CC /KP/DP/DW/DWK/Pomona
Drives: CUE
Monitoring: GRM
www.grundos.com/food-control
2.4.3 Filtering and disinection
Application
Mobile flter units or cleaning drinking water can be trans-
ported b car or helicopter to disaster areas, where immedi-
ate access to clean drinking is essential to prevent a danger-
ous sanitation disaster.
Benets
Completeremovalofsuspendedsolids
Partialremovalofdissolvedmatter(TOC,COD,BOD)
Removalofmicro-organisms:
- Log removal o bacteria (.)
- Log removal o viruses (.)
SuperbqualityasROfeedwater(lowSDI15)
Certiedforuseinpotablewater
www.grundos.com/food-control
21the sources of flooding and the solutions
7/29/2019 Design of Pumping stations
26/134
Designing a
flooD ContRol pumping
station
3 designing flood pumping stations
7/29/2019 Design of Pumping stations
27/134
3.1 General considerations
Good sump design
The sump design has a crucial impact on the pumps total
liespan. It relies on an intake structure that allows the
pumps to achieve their optimum hdraulic perormance
under all operating conditions.
The undamental condition o a good sump design is opti-
mal ow into the pumps which is a uniorm ow, ree o
submerged or surace vortices and excessive swirl.
Poor sump design
A less-than-optimal sump design could potentiall result in
poor perormance and/or mechanical strain due to vibra-
tions and cavitation at the inlet to the pump(s).
A poor design can easil lead to sedimentation o sand andrags, which in turn can cause additional cavitation and
vibration problems and excessive noise and power usage.
Sump design no go
The ollowing phenomena should be prevented or
reduced to a minimum in a properly designed pump
sump:
Non-uniformowatthepumpintake:
Results in excessive noise and vibrations, and re-
duced eciency Unsteadyow:
Can cause uctuating loads
Swirlintheintake:
Can create vortices and unwanted changes to the
head, ow, eciency and power
Submergedvortices:
Can cause discontinuities in the ow and can lead to
noise, vibration and local cavitation
Surfacevortices:
Can draw harmul air and oating debris into thepump
Entrainedair:
Can reduce the ow and eciency, causing noise,
vibration, uctuations o load, and result in damage
to the pump.
The negative impact o each o these phenomena on
pump perormance depends on the speed and the size
o the pump.
Generally, large pumps and axial ow pumps (high
speed) are more sensitive to adverse ow phenomenathan small pumps or radial ow pumps (low speed)
For special applications beyond the scope o this book,
please contact your local Grundos Water Utility sales
engineer, who will be more than happy to provide
the expertise and experience you need to meet your
specic needs.
.g./tl
designing a flood control pumping station 23
7/29/2019 Design of Pumping stations
28/134
9
8
7
6
5
4
3
Flow patterns and
boundary geometry
(see .)
2
.. Design sequence
When designing a pumping station, the design sequence is essential.
Below, we present the typical progression in the design phase and what to consider.
% o ALL
probLems
wiTH pumps
Are bAsed in
THe insTAL-
LATion And
THe Low
condiTionsAround THe
pump
Pump selection
(See .)
Minimum water level
(See .)
Determine slope
(See .)
Cross-ow velocity
(See ..)
Pump size and quantity
(see .)
Placing the pumps
(see .)
Velocity
(See .)
Dimensions
(See .)
. How much water? (Flow)
. Coming rom where?
. Going where? (Head)
Identiy the column pipe diameter
Determine the minimum submergence o the pump and by that the
minimum water level.
Check NPSH at minimum water level.
Check the bottom elevation in the inlet channel and determine i it
is necessary to slope the oor upstream o the pump bay entrance.
Maximum slope .
Compare cross-ow velocity (at maximum system ow) to average
pump bay velocity. I cross ow velocity exceeds % o the pump
bay velocity, a CFD study is recommended.
Determine the number and size o pumps required to satisy the
range o operating conditions likely to be encountered.
Determine the distance rom pump bell mouth to oor
Check the pump bay velocity or the maximum single-pump ow
and minimum water depth with the bay width set to D.
Max velocity . m/s.
Determine the dimensions o the pumping station.
1
3
Source:
Adapted rom
ANSI/HI 9.8-1998
table 9.8.2.
designing flood pumping stations
7/29/2019 Design of Pumping stations
29/134
designing a flood control pumping station 25
3.2 Design conditions
Depending on the specic condition o the area and the location o the station, you can choose
a pumping station design that meets your specic requirements.
Ask us or installation recommendations. We can oten help you create a more ecient and durable
system.
Choose the installation set-up that suits you
With the Grundos KPL and KWM pump solutions,
the individual installation has the same scope or
customisation as the pumps themselves.
Installed directly in the column pipe, KPL and KWM
pumps seriously reduce the need or constructionworks so they can even save you money beore
they prove their eciency in day-to-day operation.
combininG dierenT pump sizes
ALLows you To opTimise THe operATion
And pump To A Lower LeveL wiTHouT
dAmAGinG THe pump insTALLATion
zones o sTAGnATion sHouLd
be Avoided wiTH iLLeTs.
use cd modeLLinG To deTermine
wHere THe zones o sTAGnATion Are
7/29/2019 Design of Pumping stations
30/134
Type Open 1
Suitable where the liquid is pumped to
a tunnel, channel or basin and where
the water level is nearl constant so that
shut-o devices are not required.
Pros:
This arrangement involves the smallest
number o steel components; it consists
o a circular concrete tube and a short
pipe grouted in place as a base or the
pump. Because the top o the tube is
placed at a level slightl above the maxi-
mum water level in the outlet channel,
water cannot run back to the sump
when the pump is shut o.
Cons:
This design demands a higher pump
head.
In case on rising water level above outlet,
backow ma occur.
Type Open 2
I the water level on the outlet side o the
pump varies considerabl, ap valves can be
installed. Normall the pump works against
the head in the discharge channel or basin.
Pros:
When the pump is not in operation, the
water is prevented rom running back to the
sump b the automatic closure o the valve.
Cons:
This design has a built-in risk o water ham-
mer, which can be countered with controlled
non-return valves, i.e. a motor valve or a valve
tpe with hdraulic dampener.
3
.. Flow patterns and boundary
geometry
Beore you can select the right sta-
tion design, you need to identiy
where the water comes rom:
- Rain- Melting water rom mountains
- High water/tsunami
- Screening
And equally importantly: where
the water should be pumped to,
based on the ollowing conditions:
- Installation type
- Discharge conditions
.. Types o installation
Grundos oers turnkey solutions
or site-specic installation. In the
ollowing, we will go through the
most common solutions.
All accessories and components
can o course be adapted to your
specic requirements.
designing flood pumping stations
7/29/2019 Design of Pumping stations
31/134
designing a flood control pumping station 27
Type Open 4
Apart rom the ree discharge, this tpe is
quite similar to Open with discharge to
a closed channel.
Pumping to a closed channel can be
necessar to avoid accidents or reduce
odours.
Type FSI 1
A Formed Suction Intake can be con-
structed in steel or concrete. It improves
the inlet ow conditions to the pump and
enables a lower minimum water level.
Pros:
This tpe reduces the risk o surace
vortices and allows a lower minimum
water level. Thereore, it provides a better
defned ow to the pump. In addition, a
lower minimum water level can reduce
the size, the depth, o the pumping sta-
tion.
Cons:
I ou pump to a lower level, ou have to
consider the NPSH required b the pump.
Type Open 3
Basicall a steel version o Open .
7/29/2019 Design of Pumping stations
32/134
.. Water ow (Q)
When dimensioning pumping stations there are
many conditions to consider, such as climate
change, , and years rain, urban develop-
ment and planning. General recommendations
are thereore virtually useless, as all calculations
depend on your specic priorities.
Instead, we recommend that you ollow the na-
tional standards and legislations using the latest
tools, such as MIKE URBAN and MIKE FLOOD rom
DHI.
.. Head (H)
Any dimensioning consists o a static and a
dynamic head.
The dimensioning head H = Hgeod + Hlosses
(losses in pipes, valves, bends and aps etc).
Free outlet rom non-return ap Submerged outlet rom non-return ap
To secure suicienT HeAd iT is imporTAnT To incLude
THe dynAmic HeAd, veLociTy HeAd
3 designing flood pumping stations
M.W.L
Hgeod
M.W.L
Hgeod
7/29/2019 Design of Pumping stations
33/134
designing a flood control pumping station 29
Velocity head
Discharging to an open canal where the water
ows over a weir requires a special calculation.
In this case, it is important to include the head
contribution Hw rom the increased water level
created by the ow velocity:
For more detailed inormation on this topic,please see Appendix : Head loss calculations,page .
.. Net Positive Suction Head (NPSH)
Net Positive Suction Head (NPSH) describes conditions related
to cavitation. Cavitation should always be avoided as it causes
inecient operation and is harmul to the installation.
What is cavitation?
Cavitation is the creation o vapour bubbles in areas where thepressure locally drops to the uid vapour pressure. The extent
o cavitation depends on how low the pressure is in the pump.
Cavitation generally lowers the head and causes noise and
vibration. It rst occurs at the point in the pump where the
pressure is lowest. Most oten, this is at the blade edge in the
impeller inlet.
NPSH explained
The NPSH value is absolute and always positive. NPSH is stated
in metres [m] like the head.
Two diferent values
A distinction is made between two dierent NPSH values:
NPSHR and NPSHA.
NPSHA stands or NPSH Available and expresses how close the
uid in the suction pipe is to vaporisation.
NPSHR stands or NPSH Required and describes the lowest
NPSH value required or acceptable operating conditions. You
should always consider worst case scenarios or the ull operat-
ing range, when you use NPSHR and not only the specic duty
point.
g = , [m/s]v = Flow velocity [m/s]Q = Flow [m/s]
b = Weir width [m]
HW
Hgeod
V
M.W.L
7/29/2019 Design of Pumping stations
34/134
NPSH calculations
NPSHAcan be calculated as:
Pbar atmospherical pressure depends on your altitude.
Example:
In practical terms or column installed axial ow pumps
the calculation looks like this:
NPSHR + saety margin NPSHA (in all duty points)
NPSHR (Smin + - saety margin) = Smin + , [m]
remember To ALwAys consider npsHr or THe uLL
operATinG rAnGe, And noT onLy AT THe speciic duTy poinT.
A minimum sAeTy mArGin o . m is recommended, buT
dependinG on THe AppLicATion, A HiGHer sAeTy LeveL mAy
be required
3
For more inormation and specic pump curves, please see the KPL & KWM data booklet.
designing flood pumping stations
M.W.L
S
C
0
4
8
12
NPSH
[m]
7/29/2019 Design of Pumping stations
35/134
designing a flood control pumping station 31
.. Water velocity
Appropriate water velocity is essential or the reliability and
the eciency o a pumping station.
To avoid sedimentation and build-up o obstructions it is im-
portant to maintain sucient velocity. However it is equally
important to keep the velocity low enough to prevent pres-sure losses and vortices in the pump bay.
Velocity guidelines
Thevelocityanddistributionoftheuidowintheinlet
channel should be uniorm. The angle o the bottom
should have an inclination o to degrees.
Thevelocityofthewaterintheinletchannelshouldbeless
than . m/s.
Theoverallvelocityofthewaterinthepumpingstation
should be between . and . m/s.
Ifcross-owvelocityexceeds50%ofthepumpbayvelocity,
a CFD study is recommended.
Theeectsofowdisturbancesshouldbedissipatedasfar
as possible rom the pump intake.
Stagnationregionsshouldbeavoided.Ifthedesignhas
stagnation sections, they should be lled with concrete
beore operation commences.
In the column pipe
I water velocity is too high =>pressure loss causing excessive
energy consumption.
I water velocity is too low => sedimentation or up-concen-
tration o solids makes the water heavier and causes the
motor to trip on overload.
.. Power supply and backup
In some parts o the world, electrical grids are unstable and
power ailures are common. Although Power outage is rare in
others parts o the world, they do occur and can be down-
right dangerous i youre not prepared.
Thereore, it is important to consider emergency situations
where the regular power supply ails. A common solution is
to install a backup diesel generator that can eliminate the
headaches o long-term power outages.
Please reer to EN and local legislation.
ALTHouGH rAre in some pArTs o
THe worLd, power AiLures do
occur And musT be considered
wHen desiGninG A pumpinG sTATion
Crossflow
V
=0.5m/s
max
Pump bay
V =0.5 m/smax
V =0.3 m/smin
V =1 m/smax
To avoidsedimentation
Inlet channel
7/29/2019 Design of Pumping stations
36/134
WL MAX H
HWL MIN
HeffHteo
Hteo
Heff
..8 Trash racks and screens
Partiall clogged trash rags or screens can result in
ver uneven ow patterns and head increases.
Especiall at low water levels, a screen clogged b
sediments, oatation laer etc. can result in a con-
siderable pressure drop over the screen, reducing
the water level at the pumps. This can contribute
to vortices and cavitation in the pumps.
Reduce dead zones
One wa o preventing clogged rags and screens is
requent inspection and cleaning. However, mini-
mising scraper travel b reducing the size o the
dead zones in the screen design can also reduce
the problem signifcantl.
Screen support
Screens should be divided into several vertical
panels and supported b vertical piers; the should
never be supported horizontall, as this ma create
velocit jets and severe instabilit near the pump.
A general guideline is that a screen exit should be
placed a minimum o six bell diameters rom the
pumps. Observing these guidelines will maximise
the ow channel, thereb eliminating potential
head increases and making it eas to clean and
maintain the screens.
3 designing flood pumping stations
7/29/2019 Design of Pumping stations
37/134
designing a flood control pumping station 33
.. Handling sludge
During dry seasons, water levels recede. When this
happens, the sludge in the remaining water settles
in the sump and the problem is escalated by a slow
inow.
Sludge settlementIn this situation, additional sludge builds up in the
sump and eventually the water evaporates.
The end result may be that the impeller is buried in
silt when the pump needs to start.
Install a sludge pump
To keep the sump clean at all times, it is recommend-
ed to install a small sludge pump in a separate, small
pump sump within the main sump. This sludge pump
is used to empty the main sump in periods with lessor no inow to the main sump.
Avoid deAd zones And obsTAcLes wHere
sedimenTs And rAGs cAn buiLd up. especiALLy AT THe boTTom o THe
screens, ree pAssAGe is cruciAL
screens Are mAde rom verTicAL
pAneLs, supporTed by verTicAL piers
never HorizonTAL piers
7/29/2019 Design of Pumping stations
38/134
3.3 Pump selection
Grundos provides a ull range o pump solutions
or virtuall an purpose. Although, the solutions
are versatile and exible and eas to place in a
wide range o dierent installations, selecting the
right solution requires access to the conditionsand relevant data.
With the right data available, we can optimise the
optimal pump solution according to our exact
demands and specifc installation.
.. Axial ow propeller pump or mixed ow
pump?
With a motor range rom kW up to kW,
both Grundos KPL and Grundos KWM solutions
are designed or high-volume water handling.
KPL: Axial ow propeller pump
KWM: Mixed ow pump
KPLAxial ow propeller pump, max ow m/min, max head: m.
3
To reduce
cAbLe size
you couLdconsider A
HiGH voLTAGe
moTor.
Grundos
suppLies
moTors rom
-,
voLT
designing flood pumping stations
7/29/2019 Design of Pumping stations
39/134
designing a flood control pumping station 35
ruLe o THumb:
HeAd beLow meTres=> KpL AxiAL Low propeLLer
pump HeAd Above m=> Kwm mixed Low pump
KWMMixed ow pump, max ow 400 m3/min, max head: 50 m.
Ft M
Ft M
100
26.421.115.913.210.67.95.32.62.10
0
10
13
16
23
33
49
66
98 30
20
15
10
7
5
4
3
807060504030201080
98
66
49
33
23
16
13
10
0
0 21.1 26.4 31.7 42.3 52.3 58.1 68.7 79.3 95.11 95.7
4003603002600 80 100 120 160 200 220
30
20
15
10
7
5
4
3
M/MIN
US GPM 10
M/MIN
US GPM 10
1000KWM
1600KWM
1800KWM
1200KWM
1300KWM
1400KWM
500KWM 600KWM 700KWM 800KWM 900KWM
1000KWM
7/29/2019 Design of Pumping stations
40/134
Depth o the structure
Considering the depth o the pumping station at
the design phase is vital, as smaller pumps can
pump to a lower level than larger pumps. Conse-
quentl, smaller pumps can reduce the required
depth o the pumping station.
High ow ensures sel-cleaning and vice versa
An pumping station design should consider the
benefts o sel-cleaning. B ensuring high ow/
a sucient water velocit the design will prevent
sedimentation and the need or regular cleaning.
I operation varies much (e.g. with the seasons),
dividing the oreba and pump bas into two
halves should be considered. Thereb, ou use onl
one hal o the station in low-ow seasons.
The dividing walls with an overow gate allows
the water to ow rom one hal to the other in
high-ow seasons and in case o emergenc.
Flow below m/min => pump installationFlow below m/min => pump installation
Flow above m/min => - pump installation
ruLe oTHumb:
.. Number o pumps
Selecting the right pumps and the right
quantit o pumps depends on the load
profle: Q/H/time. In short, the ideal solution
combination is where the individual pump
operates as long as possible close to best
ecienc point.
A minimum o two pumps are required:
one dut and one stand-b pump. However,
b installing more, but smaller pumps ou
gain a more reliable and easier controllable
solution.
A sucient water
velocity enables sel-
cleaning design.
3 designing flood pumping stations
Pumpingstationdischarge[%o
fmaxflow]
Pumping station discharge duration [% of time]
0
10
20
20 40 60 80 1000
30
40
50
60
70
80
90
100
7/29/2019 Design of Pumping stations
41/134
designing a flood control pumping station 37
.. Pump selection/determine
column diameter
When Q and H have been estab-
lished, use the pump curve below
to select the right pump. Select a
pump with best ecienc point as
close to the nominal dut point aspossible.
How to select a pump
Selectapumpbasedonthe
required dut point, operating
range and saet range.
UsethecurvechartsintheKPL
& KWM data booklet.
Selectpumphydraulicsrstand
motor size aterwards.
Example o how to choose:
. Dut point (H = m and
l/s), specifed b customer.
. Operating range ( l/s to
l/s), specifed b customer.
. Q-H curve is obtained at a
propeller angle o .
. P at dut point kW.
. Pmax in operating range
kW (at a ow o l/s).
Example o how to choose motor size.
. Calculate motor size and select model:
Pmotor = Pmax * . ( % saet margin,
specifed b customer)
Pmotor = * . = . kW
Pmotor rated motor
Rated motor above Pmotor kW
Selected model: KPL....T...A.
. NPSHA (available) = m, specifed
b customer.
NPSHR (required) = m (worst case
or operating range).
NPSHA > NPSHR + . m. (accepted)
SELECT THE PUMPS
AND THE NUMBER
OF PUMPS BASED ON
LOAD PROFILE AND
HIGHEST EFFICIENCy
7/29/2019 Design of Pumping stations
42/134
.. Minimum submergence (S)
Finding the right minimum submergence o a pump is a vital design
choice, as it defnes the lowest point o the pumping station and there-
ore also a major part o the construction costs.
The Minimum Water Level (MWL) in a pumping station is usuall
defned b external conditions, including the level o the incoming pipeor culvert, or the NPSH requirements o the pump.
For NPSH requirements, see .. or the KPL & KWM Pump data booklet.
The submergence o the intake
Tpicall, the submergence o an intake should be large enough to
prevent air entraining vortices, swirling ow, and the inuence o
surace waves. This is possible in a conservative hdraulic design with a
deepl submerged intake,
although more costl than
a design in which the mini-mum submergence is onl
just adequate.
Minimum Water Level (MWL) = Clearance (C) + Submergence (S).
The clearance C = , x Column Diameter (D)
3 designing flood pumping stations
M.W.L
S
C
7/29/2019 Design of Pumping stations
43/134
designing a flood control pumping station 39
The minimum submergence is dictated b the level to avoid
ree surace vortices.
Determine the ow at minimum water level MWL. and look
up the minimum submergence rom the ollowing curves
rom ANSI/HI:
As a ast guide the ollowing table can be used or
reerence:
All dimensions in mm.
Remember to check the NPSH, please reer to ...
Minimum submergence at ow up to . litres/sec:
Minimum submergence at ow above . litres/sec:
S=
BellSubmergence,meters
Q = Flow, liters/sec.
0.5
0.0
1.0
1.5
2.0
2.5
200 400 600 800 1.000 1.200 1.4000
S=BellSubmergence,
meters
Q = Flow, liters/sec.
2.5
1.5
3.5
4.5
5.5
6.5
20.00018.00016.00014.00012.00010.0008.0006.0004.0002.0000
nalcl
dat
m.claa
m.g
m.wat Ll
d c s m.w.L500 250 1,000 1,250
600 300 1,100 1,400
700 350 1,600 1,950
800 400 1,800 2,200
900 450 2,000 2,450
1,000 500 2,200 2,700
1,200 600 2,300 2,900
1,400 700 2,500 3,200
1,500 750 2,900 3,650
1,600 800 3,100 3,9001,800 900 3,300 4,200
7/29/2019 Design of Pumping stations
44/134
flood pumping stations3
Formed Suction Intake (FSI)
The minimum water level can be optimised b using the
Formed Suction Intake Tpe , designed b the US Arm
Corps o Engineers (USACE).
This, however, increases the demand or NPSH available vs.
NPSH required:
NPSHR + saet margin NPSHA
NPSHR + Smin - HFSI saet margin [m]
HFSI is the riction loss through the FSI, which is depen-
dent on design, material, surace structure etc.
Saety margin
A saet margin o . metres is oten recommended.
However, the real margin alwas relies on the individual
conditions and has to be assessed in each case.
M.W.L
S=D
C=0.5D
designing flood pumping stations
7/29/2019 Design of Pumping stations
45/134
FSI calculation
In the ollowing calculation we have used a saet margin o . metres
including HFSI:
NPSHR NPSHA = . + Smin [m]
The USACE Formed Suction Intake Tpe allows a minimum submergenceo .*D.
To get the ull beneft o this optimised design, ou need to select a pump
that, in the ull operating range, has a NPSHR equal to or lower than . + D.
Alternativel, the minimum water level must be increased.
This table shows the
maximum allowedNPSHR i the minimum
submergence is D:
Example:
I ou select a pump or a D = , mm
column pipe, ou can allow a minimum
water level MWL = . metres i our pump
has a NPSH required below . in the
entire operating range.
I this is not the case, the minimum water
level has to be increased.
This example is based on saet margin +
HFSI = . m.
designing a flood control pumping station 41
nalcl dat
m.claa
m.g
m.wat Ll
ma.npsH th t
atg ag
d c s m.w.L npsH
[] [] [] [] []
500 250 500 750 10.0
600 300 600 900 10.1
700 350 700 1,050 10.2
800 400 800 1,200 10.3
900 450 900 1,350 10.4
1,000 500 1,000 1,500 10.5
1,200 600 1,200 1,800 10.7
1,400 700 1,400 2,100 10.9
1,500 750 1,500 2,250 11.0
1,600 800 1,600 2,400 11.1
1,800 900 1,800 2,700 11.3
0
4
8
12
NPSH
[m]
7/29/2019 Design of Pumping stations
46/134
3.3.5 Turbulence Optimiser
With an instant change in diameter, turbulence
will occur, resulting in loss o energ.
For column installed pumps this
happens between the pump volute and the
column itsel.
Reducing turbulence
The Grundos Turbulence Optimiser is a rubber diuser mounted on
the perimeter o the pump volute. The shape o the diuser is optimised
to reduce turbulence between the volute o the pump and the column
pipe in which the pump is installed.
1-2% energy reduction
The idea is relativel simple; however the
eect is outstanding.
When the pump is running, the Turbulence
Optimiser expands and adapts perectl
to the pipe. This creates a turbulence-ree
ow and reduces energ losses. In act,
the Turbulence Optimiseralone reduces
energ consumption b -%.
3
Without
Turbulence
Optimiser:
turbulence and
loss o energy.
With Turbulence
Optimiser: even
ow and ecient
operation.
designing flood pumping stations
7/29/2019 Design of Pumping stations
47/134
designing a flood control pumping station 43
3.3.6 Sensors in the pumps
Sensors help alleviate main risks
When pumps are submerged, there is a greater
risk o water entering the motor through the cable
gland and shat seal.
For that reason, most manuacturers incorporate
an oil chamber with double sealing and also ft a
range o sensors to protect the pumps oten ar
more than in smaller pumps.
Tpical sensors in large pumps include:
Bearing temperature sensors (lower and/or
upper)
Motor temperature sensors
Water-in-oil sensors monitoring the conditions
o the shat seal
Terminal box moisture sensors
Vibration sensor
Winding isolation resistance
Monitoring changes in valuesIn addition to the above pump sensor, most ap-
plications also have a sensor to keep an ee on
power consumption, voltage, operating hours, etc.
Oten, keeping an ee on changes in values is more
important than responding to absolute values.
During the commissioning stage, it will oten be
benefcial to experiment with dierent reerence
values to ascertain when action ma be called or.
Leakage sensorterminal box
Bearing temp.
Leakage sensor
Water in oilsensor
Temperature sensorfor protection ofmotor
7/29/2019 Design of Pumping stations
48/134
3 designing flood pumping stations
7/29/2019 Design of Pumping stations
49/134
designing a flood control pumping station 45
3.4 Dimensioning the pumping station
Grundos has more than ears o experience
with pumping station design. We know our
business and what it takes to design a pumping
station that will serve as a reliable guard against
ooding or minimise the consequences whenit happens.
The design guidelines in the ollowing are based
on the recommendations o the American National
Standards Institute (ANSI)and The Hdraulic
Institute.
3.4.1 Terminology and conventions
Inlet
An inlet directs water to the pumping station roma suppl source such as a culvert, canal or river.
Usuall, the inlet has a control structure such as a
weir or a gate
Forebay
The oreba serves to create a uniorm and stead
ow to the pump bas. The design o the oreba
depends on the water approach to the pump-
ing station commonl encountered as parallel
with the sump centreline, the preerred laout, or
perpendicular to the sump centreline. To secure a
stead inow to each module, it is essential to
ollow the design guidelines presented here.
Pump bay
The pumps are located in the pump ba. Once the
water ows through the pumps ba and reaches
the pump inlet, it must be uniorm and without
swirls and entrained air.
Pump bay
Forebay
Inlet area
7/29/2019 Design of Pumping stations
50/134
.. Diferent station layoutsD
min. D min. 4D D
max.20
max.10
2D
FRONT INFLOW
The inlet must be placed sym-
metrically to the pumps i water
approaches the station parallel to
the sump centreline. I the inletwidth is smaller than the width o
the pump bays, the orebay should
diverge symmetrically.
The total angle o divergence
should not exceed or open
sump intake designs or or
ormed intake designs. The bottom
slope in the orebay should not be
more than .
I these limits cannot be met, de-
vices to manage the ow direction
can improve the ow distribution.
Using model tests o these or morecomplex layouts could suggest the
optimal design.
Advantages
Balanced inow to the individual
pump bays.
Challenges
Size, and achieving enough water
velocity to prevent sedimentation.
SIDE INFLOW
An overow-underow weir can
help redistribute the ow i the
inow is perpendicular to the
axis o the pump bays. However, a
substantial head loss at the weir
is required to remove much o the
kinetic energy rom the incomingow.
Bafe systems may be used to
redirect the ow, but their shape,
position, and orientation must be
determined in model tests.
The distance between the weir or
bafes and the pump bays must be
sucient to prevent swirls and en-
trained air to reach the pump inlet.
Advantages
Compact design
Challenges
Unbalanced inow to the individu-
al pump bays.
3 designing flood pumping stations
7/29/2019 Design of Pumping stations
51/134
designing a flood control pumping station 47
3.4.3 Pump bay design
Column-installed pumps in a sump are high-
volume pumps, making them sensitive to suction
chamber conditions. Thereore, great care must
be taken to ensure sae and long-lasting pump
operation.
As we have touched upon earlier, the main design
requirement or a sump design is to provide opti-
mal inlet conditions or the pumps.
The basics
The ow being delivered to the pump units should
be uniorm, steady, and ree o swirls or entrained
air.
The dividing walls and the positioning o the
pumps must be designed in a way that avoidssurace vortices, air ingestion and entrainment,
and turbulence.
7/29/2019 Design of Pumping stations
52/134
Splitters and dividers
According to the ANSI standard .-, the open
sump intake design includes devices such as split-
ters and divider plates that alleviate the eects o
minor asmmetries in the approaching ow.
2. Formed suction intake
This design is least sensitive to disturbances o the
approaching ow that can result rom diverging or
turning the ow in the oreba, or rom single pump
operation at partial load.
Formed suction intake design
According to the US Arm corps o engineers (EM
--, Aug. .), the FSI design can be
constructed in either concrete or steel. The intake
reduces disturbances and swirl in the approaching
ow. The inclined ront wall is designed to prevent
stagnation o the surace ow.
Pump bay design variations
1. Open sump intake
This design is sensitive to non-uniorm ow, as it requires
a longer oreba and longer dividing walls between the
individual pump bas than the ormed suction intake design
installations. Furthermore, the design is sensitive to owdisturbances such as columns and beams o the civil struc-
ture o the pumping station.
FSI in concrete
FSI in steel
Open sump intakedesign
3
GRUNDFOS RECOMMENDS
USING OF OUR PATENTED
ANTI-CAVITATION CONE, ACC,
AS A FLOOR SPLITTER.
designing flood pumping stations
7/29/2019 Design of Pumping stations
53/134
designing a flood control pumping station 49
The geometrical eatures o this intake provide
or smooth acceleration and turning as the ow
enters the pump. The minimum submergence
should not be less than the column diameter.
This design is recommended or stations with
multiple pumps with various operating condi-tions
R0.08d
3.30d
1.45d
1.29d
0.78d
1.06d
D
1.08d
D
2.
31d
1.
24d
1.
28d
1.
06d
0.
88d
0.
49d
0.
16d
7/29/2019 Design of Pumping stations
54/134
3.4.4 Pumping station dimensions
Open sump design:
D
D
E=0.5D
D
X=5D
D
E
CS
Min. Water Level (MWL)
W
3
nall at
m.claa
m.g*
m.at ll*
pa th
pa lgth
llt
d c s m.w.L w x e
500 250 1,000 1,250 1,000 2,500 250
600 300 1,100 1,400 1,200 3,000 300
700 350 1,600 1,950 1,400 3,500 350
800 400 1,800 2,200 1,600 4,000 400
900 450 2,000 2,450 1,800 4,500 450
1,000 500 2,200 2,700 2,000 5,000 500
1,200 600 2,300 2,900 2,400 6,000 600
1,400 700 2,500 3,200 2,800 7,000 700
1,500 750 2,900 3,650 3,000 7,500 750
1,600 800 3,100 3,900 3,200 8,000 800
1,800 900 3,300 4,200 3,600 9,000 900
All dimensions in mm. * or the exact values o S and MWL, please reer to ..
designing flood pumping stations
7/29/2019 Design of Pumping stations
55/134
E
G
K
H
X
FC
W
D
E
designing a flood control pumping station 51
Formed suction intake (FSI),
concrete:
nall at
claa st itak
sip
a thp
a lgthFillet
Floorsplitter
d c H G w x E K
500 250 1,900 1,000 450 1,000 2,500 250 1.500
600 300 2,280 1,200 540 1,200 3,000 300 1.800
700 350 2,660 1,400 630 1,400 3,500 350 2.100
800 400 3,040 1,600 720 1,600 4,000 400 2.400
900 450 3,420 1,800 810 1,800 4,500 450 2.700
1,000 500 3,800 2,000 900 2,000 5,000 500 3.000
1,200 600 4,560 2,400 1,080 2,400 6,000 600 3.600
1,400 700 5,320 2,800 1,260 2,800 7,000 700 4.200
1,500 750 5,700 3,000 1,350 3,000 7,500 750 4.500
1,600 800 6,080 3,200 1,440 3,200 8,000 800 4.800
1,800 900 6,840 3,600 1,620 3,600 9,000 900 5.400
All dimensions in mm. Remember to check NPSH
7/29/2019 Design of Pumping stations
56/134
Formed suction intake FSI, steel:
USACE
type 10.
D
N
L
C
W
F
M
P T
M.W.L
S=D
0.5D
3
nall at
st itak si tl
d c L m n p T w
500 250 440 1,650 530 725 530 640 1,155
600 300 540 1,980 636 870 636 768 1,386
700 350 630 2,310 742 1,015 742 896 1,617
800 400 720 2,640 848 1,160 848 1,024 1,848
900 450 810 2,970 954 1,305 954 1,152 2,079
1,000 500 900 3,300 1,060 1,450 1,060 1,280 2,310
1,200 600 1,080 3,960 1,272 1,740 1,272 1,536 2,772
1,400 700 1,260 4,620 1,484 2,030 1,484 1,792 3,234
1,500 750 1,350 4,950 1,590 2,175 1,590 1,920 3,465
1,600 800 1,440 5,280 1,696 2,320 1,696 2,048 3,696
1,800 900 1,620 5,940 1,908 2,610 1,908 2,304 4,158
All dimensions in mm. Remember to check NPSH
designing flood pumping stations
7/29/2019 Design of Pumping stations
57/134
designing a flood control pumping station 53
3.5 Duty strategy - reducing the minimum water level
From an operational perspective, an water utilit
installation presents a balance. And sometimes
this balance is a compromise between initial cost
(CAPEX), and operation cost (OPEX).
Reducing CAPEX
CAPEX can be reduced b selecting pumps that are
optimised as regards size and dut strateg. In that
wa ou can construct a building that is smaller
and not so deep in the ground, i.e. less excavation,
less concrete, less cost.
Designing an oversized pumping station ma be
a reliable securit against ood situations, but an
expensive and energ inecient solution.
Reducing OPEX
OPEX can be reduced b considering the load
duration profle o the pumping station and select-
ing pumps that in groups can cover the entire
operation range as close to best ecienc point aspossible.
Both objectives, reducing CAPEX and OPEX, can
be met b grouping the pumps in such a wa that
the normal operation area is covered b the main
pumps and then have smaller pumps to pump to
the lowest level.
Pumpingstation
discharge[%o
fmaxflow]
Pumping station discharge duration [% of time]
0
10
20
20 40 60 80 1000
30
40
50
60
70
80
90
100
7/29/2019 Design of Pumping stations
58/134
Two-chamber solution
Flood control pumping stations are oten designed
to operate under high peak ows in extreme ood
situations. However, most o the ear the ow is
considerabl lower.
Oten, the fnal pumping station design ends up
being quite unsuited or both scenarios.
The challenge is that i ou optimise our pumping
station to the water velocities at peak ow, ou
will most likel have stagnating zones at lower
ow, which probabl is most o the ear.
To overcome this challenge, the station can be
divided into two chambers:
Chamber1:forlow-seasonoperation
Chamber1+2:forhigh-seasonandpeak-ow
situations.
The wall between the two chambers o the sta-
tion must have a lower section or adjustable weir
that allows the water to ow over into the second
chamber in extreme ood situations.
3
Pump groups
Pump groups enables the user to group two sets o pumps.
An example could be to run with two small pumps % o the time (tpical load profle) and then in case o heav rain
group will start.
Group 1Group 2
designing flood pumping stations
7/29/2019 Design of Pumping stations
59/134
designing a flood control pumping station 55
3.5.1 Grundos dedicated controls
Monitoring and control
Flood control pumps can be a big investment. In
addition, service and repair can be relativel costl.
Despite optimal sstem design and high qualitpumps, wear is inevitable as is the risk o ailure.
However, monitoring the condition o pumps will
lower the total lie ccle cost o the ood control
application.
Proper monitoring and control will:
Protectexpensiveequipment
Helpensureoptimumstationoperation
Reduceenergyconsumption
Helpavoidoverowandreportanyincident Optimiseservicepersonnelschedulesforpre-
ventive maintenance
Meetdemandformoreaccuratereporting,(e.g.
to compl with stricter environmental legisla-
tion)
The changes in the pump conditions described
above and the eas commissioning are the reasons
or introducing perormance on-demand control in
Dedicated Controls rom Grundos.
3.5.2 Communication modules and SCADA
implementation
For complete control o pump sstems, the
Grundos feldbus concept is the right solution.
The Communication Interace Module (CIM) and
the Communication Interace Unit (CIU) enable
data communication via open and interoperablenetworks and eas integration into SCADA sstems.
Connecting Grundos products to standard feld-
bus networks oers substantial benefts:
Completeprocesscontrol
OneconceptforGrundfosproducts
Modulardesignpreparedforfutureneeds
Basedonstandardfunctionalproles
24-240VAC/DCpowersupplyinCIUmodules
Simplecongurationandeasytoinstall Opencommunicationstandards
your Grundos CIU/CIM communication interace
solution can be connected to an SCADA, PLC or
Building Management Sstem or communication
using the applicable open protocols or wired and
wireless communication.
7/29/2019 Design of Pumping stations
60/134
3.5.3 Grundos Remote Management (GRM)
Grundos Remote Management (GRM) is a cost-
eective and straightorward wa to monitor and
manage pump installations in a water suppl and
wastewater inrastructure. It reduces the need or
onsite inspections, and in the event o an alarm orwarning, the relevant people are notifed directl.
Connecting pumps and people
Grundos Remote Management oers ou a
complete overview o our pumping sstems and
lets ou be online with our pumps on a secure
network hosted b Grundos. you can monitor en-
erg consumption, share documentation, manage
service and maintenance, and maintain a exible
on-call schedule.
As opposed to traditional SCADA sstems, GRM is
ideal or everone who does not require remote
process automation. The initial investment is mini-
mal, and a fxed low ee covers data trac, hosting
costs and sstem support, including back-up o all
data.
Grundos Remote Management oers man ad-
vantages or managing our critical installations:
Wastewater and ood pumping stations
Monitor standard wastewater pumps, sensors
and controllers o an make and model, including
automatic reports o operational data.
Water treatment plants
Monitor ow and pressure sensors, tank levels,
pumps and securit alarms, including automatic
reports o power consumption and operational
data.
Mines and construction sites
Receive alarms rom dewatering pumps immediate-
l in the critical event o breakdown or malunction.
3 designing flood pumping stations
Receive
CIU27
Monitor system
Manage system
Optimiseand report
Pumpsand controls
7/29/2019 Design of Pumping stations
61/134
designing a flood control pumping station 57
3.5.4 Motor Protection (MP204)
Protect your pumps against external threats
The MP protects pump motors against under volt-
age, over voltage and other variations in power suppl.
So even i our external power suppl is not entirel
stead, our pump will continue its stead perormance.your pump motors will also be protected against the
overheating that accompanies such variations and
reduces pump lietime.
Phase errors are a requent cause o problems or
pumps o this tpe. Ater ou set the relevant phase
( or ) during set-up, the learning unction o the
MP registers the correct phase and reacts i things
are not right.
The MP also monitors pump power consumption.As reduced power consumption is a strong indication
that the pump is about to run dr, the MP will im-
mediatel stop the pump i the power consumption
drops below %.
Maximum uptime is ensured, preventing interruptions
in boosting perormance. All this in a unit that can be
set up or operation in just minutes.
7/29/2019 Design of Pumping stations
62/134
3.5.5 Variable requency drives (CUE)
Grundos CUE is a series o variable requenc
drives designed or speed control o a wide range
o Grundos pumps. The CUE contains the same
control unctionalit as the Grundos E-pumps.
Reasons or emploing automatic requenc con-
trol can both be related to the unctionalit o the
application and or saving energ.
For example, automatic requenc control is used
in pump applications where the ow is matched
either to volume or pressure. The pump adjusts
its revolutions to a given set point via a regulating
loop. Adjusting the ow or pressure to the actual
demand reduces power consumption.
Energy vs. reliability
Reducing the power consumption is o course
recommended, but never without considering the
velocit.
Finding just the right balance is optimal, as high
speed will remove sedimentation
in the column, but increase en-
erg cost. And low speed reduces
energ costs, but increases the
concentration o solids in the
column. This makes the water
heavier and causes the motor to
trip on overload.
Flush cycle
The problem o sedimentation
and a high concentration o solids
in the water can be solved b an
intelligent controller.
A Grundos dedicated controller will automaticall
speed up the pumps to run a ush ccle, or a back
ush unction to prevent these common problems.
3.5.6 Sot starters
Sot-start eliminates the start-up power surgeassociated with conventional pumps, imposing
minimal demand on inverters and generators.
In the Column pIpe
i veLociTy is Too HiGH
pressure Loss (enerGy)
i veLociTy is Too LowsedimenTATion or HiGH
concenTrATion o soLids
u t tat a
t
t th la th
l aatg t a
.wh g tl t tat
t th at
th a th t t
a at that a ta t th
at th tt t.
Th a t t ajt t t
th t.
3 designing flood pumping stations
7/29/2019 Design of Pumping stations
63/134
designing a flood control pumping station 59
3.6 Other considerations or the construction
3.6.1 Support beams and columns or the building
I horizontal beams cannot be avoided, it is impor-
tant to consider the normal water level and place
the beams above this.
Prevent the bull whip efect
Even narrow submerged beams can cause consid-
erable waves in the pump ba, also known as the
bull whip eect.
CFD analysis is recommended
When placing columns to support the structure,
consider the shadow areas the create and intro-
duce fllets where appropriate.
The fllets prevent stagnation regions and sedi-
mentation. I possible, such stagnation regions
should be flled with concrete beore operation
commences.
Need assistance?
For the best results, eel ree to contact our experts
at the Grundos Water Utilit Competence Centres
during our planning stages.
We can assist with everthing ou need
within pumping station design, pump selec-
tion, uture requirements, and the total Lie
Ccle Costs.
The Grundos Water Utilit Competence
Centres are located in Copenhagen and
Aurora in the USA.
For more inormation, please visit:
www.grundos.com/food-control
Horisontal support beam
7/29/2019 Design of Pumping stations
64/134
7/29/2019 Design of Pumping stations
65/134
7/29/2019 Design of Pumping stations
66/134
. Time: Its ast
. Economy:Attractive cost
. Flexibility:Parameters andgeometry can easilybe adjusted
. Visual:Accurately uidows and pressurein the system
Why use
CFD?
Vector and
contour plot, and
streamline o the
ow eld, show the
ow direction and
velocity.
4 designing flood pumping stations
7/29/2019 Design of Pumping stations
67/134
4.2 Model testing
Building an actual model o a pumping station
can be the appropriate solution in some pumping
station projects. This is especially the case when
seeking solutions to problems in existing stations.
I the cause o a problem is unknown, building amodel o the pumping station can be a cost-eec-
tive and very ecient way to determine the source
o the problem.
Model testing allows designers to test alternative
solutions in a real lie model rather than trial and
error at ull scale. Thereore, model testing can
provide a tried and tested pumping station design
or the perect remedy to a complex problem.
cfd and model testing 63
Representations o two model pump units.
Wet well, complete with benching, bafe wall, 500 mm
interconnecting level equalisation pipe and representations
o two model pumps.
Physical
hydraulicmodel testing.
The ormation o a submerged side wall vortex.
7/29/2019 Design of Pumping stations
68/134
VoRtex
anD how to
pReVent it
designing flood pumping stations
7/29/2019 Design of Pumping stations
69/134
What is a vortex?
A vortex is a region within a uid where
the ow is mostly a spinning motion about
an imaginary axis, straight or curved. That
motion pattern is called a vortical ow or
vortex.
How do they orm?
Vortices orm spontaneously in stirred uids,
and are a major component o turbulent
ow. In the absence o external orces,
viscous riction within the uid tends to or-
ganise the ow into a collection o so-called
irrotational vortices.
Vortex explained
Within such a vortex, the uids velocity
is greatest next to the imaginary axis anddecreases in inverse proportional distance
rom it. The vorticity (the curl o the uids
velocity) is very high in a core region sur-
rounding the axis and nearly zero in the
rest o the vortex; while the pressure drops
sharply as one approaches that region.
Vortices in pumping stations
Vortices in pumping station should be
avoided or minimised as they can cause air
entrancement in the pump and cavitation.
. Types o vortices
Vortices are a result o ow, speed and pressure and can be ormed rom
the surace when the water level is too low but can also be ormed
submerged rom the back or side wall or rom the oor.
Heres a quick overview o the most common types o ree surace
vortices:
. Surace swirl
. Vortex pulling air bubbles
. Dye core to intake:
coherent swirl
. Vortex pulling oating trash
but not air
. Surace dimple
. Full air core to intake
vortex and how to prevent it 65
7/29/2019 Design of Pumping stations
70/134
7/29/2019 Design of Pumping stations
71/134
.. Submerged vortices
Problem:
Submerged vortices are oten dicult to detect rom
above the ree surace, as they orm almost any-
where on the solid boundary o the sump.
In act, only erosion o the propeller blades or rough
running o the pumps may reveal them.
Solution:
Submerged vortices can be eliminated by disturbing
the ormation o stagnation points in the ow. Addi-
tion o a centre cone or a splitter under the pump, or
insertion o llets and benching between adjoining
wall may correct the ow pattern.
vortex and how to prevent it 67
A: Anti Cavitation Cone ACC
B: Back wall splitter
C: Floor splitter
E: Back wall fillets
F: Side wall fillets
D: Corner fillets
7/29/2019 Design of Pumping stations
72/134
.. Air-entraining vortices
Problem
Air-entraining vortices develop either in the wake o the
pump tube i the inlet velocity is too high or the depth o
ow is too small. And i the velocity is too low, they develop
upstream rom the pump.
Solution
Air-entraining vortices can be eliminated by adding extra
turbulence to the surace ow. Placing a transverse beam
or bafe at a depth equal to about one quarter o the tube
diameter and at a point about .. diameters upstream
o the tube may solve the problem.
I the water levels vary signicantly, a oating beam and a
oating rat (plate or grid) upstream o the tube may be a
better choice to eliminate air-entraining vortices.
A possible alternative is the use o an inclined plate.
5 designing flood pumping stations
D1.5-2D
D / 4
Surface bafflefor vortex suppression
Floating raft or vortexbreaker grid
7/29/2019 Design of Pumping stations
73/134
vortex and how to prevent it 69
5.3 Retrotting FSI,Formed Suction Intake
I you run into cavitation and vortex problems, it is
possible to establish a ormed suction intake e.g. by
means o steel plates:
5.5 Reducing surace vortexby retrotting a bafe
I you run into cavitation and vortex problems, it is possible
to establish a ormed suction intake e.g. by means o steel
plates:
5.4 Retrotting back-wall andoor splitters
The rst and most cost
eective step to take when
running into problems is to
install a oor splitter, e.g.
as a steel plate, shaped and
bolted to the pump bay
oor.
pLeAse noTe THAT THe Loor spLiTTer
musT be A sinGLe vAne, pArALLeL To THe
pump bAy wALL in THe cenTreLine o
THe pump, noT A cross.
7/29/2019 Design of Pumping stations
74/134
aCCessoRies
designing flood pumping stations
7/29/2019 Design of Pumping stations
75/134
6.1 Column pipe
Column pipes are typically manuactured locally
according to the design recommendations o
Grundos, but can o course also be ordered rom
your local Grundos company.
In addition, the seat ring in the bottom o the
column pipe can be ordered rom Grundos;
please reer to KPL and KWM data booklet.
The seat ring is welded to the column pipe.
6.2 Anti Cavitation Cone (ACC)
The patented Anti Cavitation Cone provides an optimal
inlet ow to the pump.
Cavitation and the noise and vibrations associated with
this harmul process can be prevented by tting an anti-
cavitation cone below the pump just beneath the suction
bowl.
The ACC will prevent:- Cavitation
- Pre Swirl
- Fluid separation phenomenon
- Reduce vortices
Advantages:
Reduces noise and vibrations and extends the lietime o
the pump.
accessories 71
7/29/2019 Design of Pumping stations
76/134
6.3 Splitters
Back wall and oor splitters can be ormed in concrete
or manuactured in steel.
The stainless steel version is typically bent or made rom
a welded stainless steel sheet or a hot dip galvanisedT-bar.
A back wall splitter should end above the maximum
water level.
A oor splitter should pass the column pipe. The total
length o the oor splitter should be . - . diameters
rom the back wall.
I you need urther inormation or additional advice,
please contact your local Grundos company.
6.4 Cable entry
When designing the column pipe including the lid top, we
recommend side-entry o the cables. In comparison with a
top entry through the lid, side entry improves handling
during service.
There are several cable entries available on the market, and
cable entries can also be ordered rom Grundos.
6 designing flood pumping stations
7/29/2019 Design of Pumping stations
77/134
7/29/2019 Design of Pumping stations
78/134
Cable
suspension
system.
Securing
the cable to the
liting chain.
6 designing flood pumping stations
7/29/2019 Design of Pumping stations
79/134
7/29/2019 Design of Pumping stations
80/134
gRunDfosseRViCe & solutions
designing flood pumping stations
7/29/2019 Design of Pumping st