Design of Pumping stations

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Designing

flooD pumping

stations


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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


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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


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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


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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


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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.



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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

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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


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Grundos ood control installations worldwide

5introduction


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Source: UNISDR

designing flood pumping stations1


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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


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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



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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


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the souRCes

of flooDing anD

the solutions



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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?


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.. 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



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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


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Pump gate

2.3.5

Service

7.0

Main pumping station

2.3.3

2.2 The sources o ooding



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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.



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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.


RAINFALL

STORM SURGE

EARTHQUAKE

FLASH FLOODS

INLAND

ESTU

ARY

COAST

RIVER FLOODS

COASTALFLOODS

TSUNAMIS

DISCHARGE

DISCHARGE

WATER LEVEL& WAVES

WAVES

KEY FACTORSTIME

RAINFALL


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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




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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



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





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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



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


Drives: CUE

Monitoring: GRM




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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.



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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


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




26/134

Designing a

flooD ContRol pumping

station



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


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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.



29/134


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


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.



31/134


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 .


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


M.W.L

Hgeod

M.W.L

Hgeod


33/134


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


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.


M.W.L

S

C

0

4

8

12

NPSH

[m]


35/134


.. 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


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.



37/134


.. 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


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



39/134


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


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.


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


41/134


.. 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


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)


M.W.L

S

C


43/134


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


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



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.


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]


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.



47/134


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


48/134



49/134


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


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.



51/134


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.


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.



53/134


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


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 ..



55/134

E

G

K

H

X

FC

W

D

E


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


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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



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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


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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



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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.


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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.


Receive

CIU27

Monitor system

Manage system

Optimiseand report

Pumpsand controls


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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.


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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.



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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:


Horisontal support beam


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. 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.



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.


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VoRtex

anD how to

pReVent it



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


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.. 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.


A: Anti Cavitation Cone ACC

B: Back wall splitter

C: Floor splitter

E: Back wall fillets

F: Side wall fillets

D: Corner fillets


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.. 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.


D1.5-2D

D / 4

Surface bafflefor vortex suppression

Floating raft or vortexbreaker grid


73/134


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.


74/134

aCCessoRies



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


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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.



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Cable

suspension

system.

Securing

the cable to the

liting chain.



79/134


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gRunDfosseRViCe & solutions


7/29/2019 Design of Pumping st

Design of Pumping stations

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