Course 1 Raw Material Extraction

1.2 Water Drainage Systems

Imprint

German Cement Works Association

Research Institute of the Cement Industry
P.O. box 30 10 63, 40410 Duesseldorf, Germany
Tannenstrasse 2, 40476 Duesseldorf, Germany
Phone: +49 211 45 781
Fax: +49 211 45 78296
info@vdz-online.de
www.vdz-online.de

info@elearning-vdz.de
www.elearning-vdz.de

Issued: 7th January 2013

Contents
1 Introduction....................................................................................................... 1
2 The Need for Drainage ..................................................................................... 1

3 Use of Water ...................................................................................................... 2

4 Structure and Operating Principle of Drainage Systems ............................. 2
4.1 Collecting Ponds................................................................................................. 2
4.2 Separator Systems............................................................................................... 3
4.3 Pump Stations ..................................................................................................... 4
4.4 Pump Technology ............................................................................................... 5
4.4.1 Centrifugal Pumps .............................................................................................. 6
4.4.2 Spiral Housing Pumps ........................................................................................ 8
4.4.3 Submersible Pumps ............................................................................................ 8
4.4.4 Characteristic Numbers for Pumps..................................................................... 9
4.4.5 Cavitation............................................................................................................ 12
i
4.5 System Components ........................................................................................... 13

5 Health and Safety Practices ............................................................................. 16

6 Operation and Quality ..................................................................................... 16

7 Environmental Protection ................................................................................ 17

8 Maintenance and Inspection............................................................................ 17

9 Questions on Course LB 1.2 Water Drainage Systems .............................. 18

Solutions............................................................................................................................... 19
Glossary ............................................................................................................................... 21
Index..................................................................................................................................... 22

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1 Introduction

Excavation in the quarries of cement works and the resulting changes to the natural drainage
system lead to a real need for drainage measures.
In this course you will learn more about the strategies and techniques used for drainage
as well as the respective legal requirements. In particular you will learn about pumps and
other system components used to transport the waters accumulating in quarries.
Course Summary

2 The Need for Drainage

Only limited drainage systems are generally needed if the excavation is carried out in hilly Excavation in
or mountainous terrain and the excavation area lies above the natural drainage channels. Mountains

The situation is more problematic over flat terrain where the excavation areas lie below Excavation in Flat
the natural drainage channels or the ground water table. In this case a complex drainage Terrain

system is required as rain water runs off all the open quarry faces and from some of the 1
adjoining areas into the quarry (Fig. 2.0-1 top right-hand corner). If no drainage system
were used, the excavated area would fill up to the natural overflow point. Examples of this
can be seen in many former quarries which now enhance the landscape as lakes (Fig. 2.0-1
bottom left-hand corner).

Figure 2.0-1: Quarry with Drainage System (top right) and without Drainage System (bottom left) .

When designing retention basins or ponds not only the quarry area itself and the adjoining
terrain must be taken into account but also the prevalent precipitation regime. In partic-
ular strong catastrophic down-pours with a precititaion of more than 10 mm in one hour
encountered in violent rain storms must be taken into account. They can lead to dangerous
flash floods.
Drainage systems and their respective components are subject to the legal provisions.In Legal Requirements
Germany these are stipulated e.g., in the German Water Resources Policy Act and the
respective State Water Acts passed by the German Federal States.
The duty to obtain authorization as well as the official responsibilities and the technical
standards to be observed with regard to drainage systems are set out in such regulations.
In most countries routine inspections on drainage systems have to be performed and cor- Inspection
responding documentation has to be maintained. andDocumentation
Obligation

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 4 Structure and Operating Principle of Drainage Systems

3 Use of Water
Diversion Some of the water that collects in retention ponds is diverted directly into drainage ditches
or streams.
Economic Use However, it is also possible to use this water economically for cement production in the
form of process water to cool mechanical systems and/or for conditioning in the evapo-
ration coolers for the exhaust gases.
Due to the specific legal provisions governing this aspect in some countries, these two uses
might require separate authorization/permits.

4 Structure and Operating Principle of Drainage

Systems
Drainage systems generally consist of a technical part and the body of water or pond
from which the water must be removed. The technical part consists mainly of pumps and
2
pipelines and, where appropriate, separator systems for retaining contaminants.

4.1 Collecting Ponds

Water always collects at the lowest point which in a quarry is known as the quarry floor
. Collecting ponds make use of this natural property of water, which is diverted through
excavated channels to the most favourable point for the drainage system. Ponds of this
type are generally located either below the quarry floor (Fig. 4.1-1) or cover part of it (Fig.
4.1-2).

Figure 4.1-1: Pond Below the Quarry Floor .

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 4.2 Separator Systems

3
Figure 4.1-2: Pond Covering Part of the Quarry Floor .

4.2 Separator Systems

Separator systems are technical facilities that remove contaminants from incoming or
in-situ water. Definition

The main contaminants are suspended material and oil residues from machinery.
Examples of suspended material include: Suspended Material
 dust from the quarry
 combustion soot from motor vehicles
 residues from blasting
Oil residues may originatee.g. from the following: Oil Residues
 leaks in hydraulic systems
 fuel residues
 spilled engine oil

Figure 4.2-1: Technically Complex Separator System .

Separators may be complex technical systems used to prevent the pollution of bodies of Two Types: Technical
and Natural

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 4 Structure and Operating Principle of Drainage Systems

water (Fig. 4.2-1), as described in courses 1.3 Lorry Washing Systems and 7.6 Waste
Water Disposal. However, simple systems can also be installed with the natural materials
present in the quarry. Fig. 4.2-2 shows a separator system of this type with settling basins
for heavy and light suspended materials.

4 5
1 3
2

Figure 4.2-2: Separator System Produced Using Natural Material .

1 Pump station

4 2 Collecting pond

3 Swan-neck

4 Dam

5 Settling pond

Table 4.2-1: Key to Fig. 4.2-2.

Operating Principle of The incoming water is stored temporarily in the settling pond (right). Dust and other
Settling Basins suspended materialsheavier than water settle on the bottom can be removed from time to
time with a clearing device. Light materials remain on the surface of the water where they
are prevented from flowing away by the swan neck run-off. They can be skimmed off more
easily at this point than on the collecting pond below or they can be bonded with binding
agents.
The deposition effect of settling ponds of this type ensures that
 the collecting pond is kept largely free of sludge,
 the collecting pond is kept free of oil residues,
 the proportion of suspended material in the water of the collecting pond is reduced
considerably.
Separator systems of this type are generally constructed with a dam of overburden material
and are compacted with respective equipment. Deposition of the suspended material in the
water body ensure that the dam becomes water-tight within a very short period of time as
the prevailing water pressure is not very high due to the low water level of generally less
than 1.5 m.

4.3 Pump Stations

The water level in the collecting pond is maintained by pump stations. These are either
floating units with fixed pumps or pump houses with hose connections to the strainer.
The water level is controlled by float switches.

Floating Units
Floating units on pontoons (Fig. 4.3-1) have relatively low installation costs. The pump
is set in a frame inside the float. A centrifugal pump is generally used, with its impeller

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 4.4 Pump Technology

or pump body installed beneath the water surface. Standard electric motors can be used as
drives in this above-water configuration.

Figure 4.3-1: Floating Unit for a Pump Station (Pontoon) .

Advantages Disadvantages

suitable for shifting locations, no suction lines operation more costly in winter
required not possible to protect the pipelines against
low technical effort for electrical installation freezing
robust pump operation continuous discharge of water only with
design with lower susceptibility to failure and freeze-protection measures
lower investment costs than submersible
motor-driven pumps

Table 4.3-1: Advantages and Disadvantages of Pump Stations.

Pump Houses
Pump houses are permanent buildings erected on dry land above the respective pond. In
them are installed spiral housing pumps which are connected via a suction line to the
pond to be dewatered.

4.4 Pump Technology

Complex pump technologyare employed wherever large volumes of water have to be con-
veyed continuously.
In total, approximately 400 different types of pumps are currently known. A basic distinc- Types
tion is made between
 flow pumps , here also referred to as centrifugal pumps,

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 4 Structure and Operating Principle of Drainage Systems

Advantages Disadvantages

suitable for fixed locations high installation costs

operation not affected by weather pump design with suction line and strainer
weather-protected pump installation no self-priming operation
pumps protected against freezing by insulated sensitive strainers
installation lower efficiency
pump operation not affected by freezing
conditions

Table 4.3-2: Advantages and Disadvantages of Pump Houses.

 and positive-displacement pumps , such as the reciprocating pumps used in

older wells.
Principles The two types differ in their use of different physical properties: positive-displacement
pumps use the vacuum in a cavity to transport liquids while centrifugal pumps are based
6 solely on the principle of the flow of liquids. In the latter type of pump the suction line
must therefore always be filled with water, whilst reciprocating pumps are in principle
self-priming.
Course Summary As part of this course you will learn more about the principle of centrifugal or flow pumps,
particularly about spiral housing and submersible motor-driven pumps.
You will also learn about the conveying capacities and fields of application of the respec-
tive types of pumps as well as their relevance to quarries. You will also gain an insight
into the physical phenomenon of cavitation which may adversely affect the life of
centrifugal pumps if used incorrectly.

4.4.1 Centrifugal Pumps

The pumps mainly used in water drainage systems belong to the group of radial centrifu-
gal pumps.
OperatingPrinciple The basic principle behind the operation of radial centrifugal pumps may be described by
comparing it to fans or vacuum cleaners:; suction, compression and transport.
The central component of a centrifugal pump is the impeller . It is mounted on a drive
shaft and runs in the liquid and draws the liquid from the suction pipe and forces it into the
pressure pipe. Liquid is prevented from escaping at the rotating shaft by a standardized
shaft seal .
At this point in the online course you will see an animation of the centrifugal pump instead
of this image.

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 4.4 Pump Technology

Figure 4.4-1: Parts of a centrifugal pump.

1 Pump head

2 Impeller

3 Suction pipe flange

4 Pressure pipe flange

5 Electric motor

6 Drive shaft

7 Shaft seal

Table 4.4-1: Key to Fig. 4.4-1.

Advantages and disadvantages of these two types of pumps are compared to each other in
Tab. 4.4-2.
Advantages Disadvantages

An advantage of centrifugal pumps is that they con- Compared to reciprocating pumps, centrifugal
vey liquid without fluctuations in pressure and pumps are less efficient and are not self-priming.
have a technically simple design. This implies that the suction pipe of the centrifugal
pump has to be filled with liquid before operation.
The proportion of air in the suction pipe should
also not be too high, as this will stop the conveying
process.

Table 4.4-2: Advantages and Disadvantages of Different Types of Pumps.

The various types of centrifugal pumps are categorized and named in accordance with Types
different criteria:
 impeller shape
 housing design
 number of stages

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 4 Structure and Operating Principle of Drainage Systems

 drive
 conveying media
 application

4.4.2 Spiral Housing Pumps

Type of Centrifugal Spiral housing pumps (Fig. 4.4-2) belong to the group of centrifugal pumps. They are
Pump normally fitted in dry installations with the pump foundation in the pump house (Fig. 4.4-
3).
The pump housing and electric drive are connected via a coupling. Spiral housing pumps
require a suction line ending in a strainer (see system components strainer).

Figure 4.4-2: Radial Spiral Housing Pump (Standard Pump DIN 24255) for General Clean Water
Supply (Source: KSB) .

4.4.3 Submersible Pumps

Type of Centrifugal Submersible motor-driven pumps are centrifugal pumps of special design. Their fields of
Pump application include
 underwater pumps (Fig. 4.4-4) in a wet installation for drainage of quarry pits and
depressions, or
 dry-installation submersible motor-driven pump assemblies (Fig. 4.4-5), for example
as pontoon pumps.
WetInstallation Wet installation submersible motor-driven pumps:
 Generally used directly in flooded depressions
 Not suitable for direct removal of water
 High wear caused by close contact with water contaminants
 Larger pumps have to be suspended in a corresponding frame for protection against
input surge

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 4.4 Pump Technology

Figure 4.4-3: Dry Installation of a Spiral Housing Pump (Source: KSB) .

 In the case of wet-installation submersible motor-driven pumps the quality of the water
discharged does not comply with legal requirements for suspended material especially
when the pump is installed close to the floor of the pond.
Dry-installation submersible motor-driven pumps: DryInstallation
 Dry-installation pumps (see Fig. 4.4-5) that are fitted on a float and draw off water
from the surface of the water in a controlled manner have a number of advantages.
 As drives of dry-installation submersible pumps cost-effective standard motors IP
54/65 are used.

4.4.4 Characteristic Numbers for Pumps

Pump output can be characterized by characteristic numbers. In principle, each type of

pump has its own characteristic curve composed, inter alia, of its transport capacity, ef-
ficiency and delivery head. When designing a drainage system , careful consideration
should be given as to which pump type is used for which application.
The output of a pump, i.e. the actual amount of water conveyed, generally does not cor- Nominal Output
respond to the nominal output of the pump given on the specification plate. The nominal
output of the pump, consisting of delivery head and output, is calculated purely mathemat-
ically.
In addition to the nominal output there is the actual output which is based on Actual Output
 the alignment of the conveying pipeline,
 the longitudinal profile of the pipeline, and

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 4 Structure and Operating Principle of Drainage Systems

10

Figure 4.4-4: Submersible Motor-Driven Pump as an Underwater Pump (Source: KSB) .

 the cross-section of the pipeline and any possible constrictionslike impeller meters for
measuring water volume.
Cavitation may also considerably restrict the capacity of the pump (see Ch. 4.4.5).
The actual output of a pump station can only be determined by a calibrated water meter.
Characteristic Numbers The following characteristic numbers are relevant for centrifugal pumps:
 output
 delivery head
 coupling power
 efficiency
 positive suction head
 rotational speed

Characteristic Curve The characteristic curve of a centrifugal pump describes the relationship between
pressure increase and output.

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 4.4 Pump Technology

11

Figure 4.4-5: Submersible Motor-Driven Pump as a Dry-Installation Submersible Motor-Driven Pump

Assembly .

The optimum operating point of a pump can be determined with the characteristic curve of
the connected pipe network. In Fig. 4.4-6 it is shown as the point of intersection of the two
characteristic curves. In principle, the maximum pressure of a pump is achieved with an
output of 0. In this case the pump would push against a closed valve. The pressure in the
entire pipe system rises with increasing output of the pump. At the point of intersection
of the two lines, the pressure and conveying volume of the pump and pipe system achieve
optimum conditions for continuous operation of the system.

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 4 Structure and Operating Principle of Drainage Systems

open system

pipe / net

conveying height [m]

characteristic curve

pressure /
working point / operating point

characteristic curve of the pump

h geo.

12 output Q or V [m/h]

h geo. = geodetic height

Figure 4.4-6: Characteristic Curve of a Pump (Source: Wikipedia) .

Relationship between Speed, Delivery Head and Output

What happens if the speed (rotational speed) of the pump is doubled?
 The output also doubles ,
 the delivery head is quadrupled and
 the electric power consumption of the pump increases by as much as 8 times.

4.4.5 Cavitation

The main problem encountered with centrifugal pumps is cavitation. This physical
phenomenon may lead to considerable losses in output and may even cause the complete
destruction of the pump.

Cavitation is the formation and abrupt collapse of minute vapour bubbles.

At this point in the online course you will watch an animation on cavitation.
Definition
The formation of cavitation can be described as follows: As the result of a reduction
Formation in pressure in the pump inlet due to the acceleration of the flow, a reduction in system
pressure or a decrease in the suction level causes the vapour pressure to be reached in
some places. The liquid vapourizes with a considerable increase in volume. As the flow
proceeds through the impeller, the pressure rises further. The vapour condenses with an
implosive reduction in volume; As a result micro-jets of water are formed in quick succes-
sion that generate pressures of up to several thousand bar during concentrated impact on
the impeller vanes and pump housing.
Causes Cavitation may be caused by an ineffective inward flow to the pump in the suction re-
gion because of an excessively narrow pipeline or in-take of air or by the pump being
inadequately designed with regard to the pressure-volume product.
Symptoms: crackling Cavitation therefore represents a disruption of the flow, in particular at the start of energy
noise and material wear conversion at the impeller. This disruption to the flow affects the characteristic curves of

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 4.5 System Components

the pump as a result of a decrease in efficiency and delivery head. Vibrations caused by
the sudden condensation processes are also produced, resulting in crackling noises and
material wear.
The inner pump surfaces are attacked both
 mechanically by high-speed jets ( cavitation erosion ) and
 chemically by the destruction of the top material layer ( cavitation corrosion )
.
Nickel chromium steels with an appropriate shape and surface quality are resistant to cav- Countermeasures
itation.
A reliable pump design is required to prevent cavitation damage to pumps or even a loss
of function of the entire pump station.
The design includes an assessment and calculation of resistance of the conveying pipeline,
influenced by:
 pipeline length
 pipeline radii
 total delivery head, taking into account the delivery head curve. 13

4.5 System Components

The following drainage system components will be discussed in this section:
 strainers (p. 13)
 filling connections (p. 14)
Overview
 pressure meter (p. 14)
 pipelines (p. 14)
 flexible hose lines (p. 14)
 rigid pipelines (p. 14)
 pipeline valve (p. 15)
 water meter (p. 16)

Strainers
Centrifugal pumps are not self-priming pumps so the suction line of dry-installation pumps
must be secured by a strainer (Fig. 4.5-1) with a shut-off valve (closure bell) to prevent
the pipeline from emptying. The screen of the strainer prevents contaminants from being
drawn in whilst the shut-off valve prevents the line from emptying.

Figure 4.5-1: Intake Element with a Fine Screen .

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 4 Structure and Operating Principle of Drainage Systems

An additional large, coarse intake protection strainer is recommended for intake strainers
suspended close to the surface. These may e.g. keep larger pieces of foils away from the
strainers, preventing them from becoming completely blockedand stopping pump output.

Filling Connections
A connection for filling the suction line with external water should be provided in pumps
with suction lines, and a ventilation connection should be fitted at the highest point in the
line.

Pressure Meter
A pressure meter on the pressure side of the pump gives trained operators an indication
of the state of the system.
14

Pipelines
Water is conveyed to the pumps by pipelines and the water conveyed by the pumps is fed
to drainage ditches or streams. A basic distinction is made between
 rigid pipelines and
 flexible hoses.

Rigid Pipelines
When laid as permanent lines, such lines take the form of rigid pipelines made of plastic or
steel. The diameter of the pipeline is based on the volume to be conveyed and the length
of the pipeline. The course of the pipeline along the ground is generally adapted to the
natural terrain.
Note! The following should be avoided
 tight radii
 excessive increases in height
 excessively small pipeline cross-sections
 pipeline depressions that are not protected against freezing
 poorly accessible strainers
Frost Protection When laying the pipeline care should be taken to ensure that the entire pipeline is protected
against freezing or that outlet devices are provided at the lowest points of the pipe system.
Pipelines laid without frost protection must be either regularly flushed or drained during
operation in winter.

Flexible Hoses
Flexible hoses (Fig. 4.5-2) are generally laid as connection lines to fixed pump stations
where water levels fluctuate as they are the best way of adapting to changes in the water
level and ensuring trouble-free operation.
In addition, different grades of flexible hose can be laid where the installation location is
subject to change.
Freeze Protection One drawback of this type of installation is its sensitivity to freezing.

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 4.5 System Components

15

Figure 4.5-2: Pump Station with Connected Flexible Hoses .

Pipeline Valves
Pipeline valves (Fig. 4.5-3) are used at each of the distribution points in the pipeline to
control distribution and direction. These valves can be set either manually or automat-
ically, pneumatically or electrically. As these rotary valves have pivot points they are
sensitive to large foreign bodies in the water and should be protected accordingly by an
intake screen.

Figure 4.5-3: Pipeline Valve .

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 6 Operation and Quality

Water Meters
Water meters are generally incorporated at accessible points over the length of the pipeline.
They monitor water volumes for statistical purposes or to comply with official regulations.

16

Figure 4.5-4: Water Meter, External View .

There may e.g. be an official regulation requiring regular calibration of the meter on the
manufacturers test stand. The meters must therefore be accessible and protected against
freezing.

5 Health and Safety Practices

Regular Checks In accordance with current German Employers Liability Insurance Association regula-
tions, electrical systems in aqueous environments must be checked particularly carefully
and regularly. In other countries similar regulations should exist.
Precautionary Since pump stations are only checked occasionally in practice, the preventative measures
Measures for reliable operation of the system and for protection against flooding should be carried
out with particular care and attention. This also includes the freeze-resistant set-up of the
float switch and strainers.
Control Room With the present normal industrial equipment, pump stations can also be monitored di-
Monitoring rectly from the central control rooms via an electronic connection. For longer distances
the operation can also be monitored by radio transmission.

6 Operation and Quality

Operation
Protection Against If the pump systems fail, the cooling water supply to the plant may be put at risk. The
Failure systems should therefore be designed with redundancy for such a situation.

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With pump stations in quarries, care must be taken to ensure that loading points and access Protection Against
routes are kept sufficiently clear as operation of the quarry may otherwise be disrupted by Flooding

flooding after very heavy rainfalls.

Failure of the drainage system or insufficient drainage may lead to serious disruptions in Possible Effects
the supply of raw materials to the kiln plant.

Product Quality
Interruptions to quarry operation caused by insufficient drainage may ultimately lead to
disruptions in kiln operation and associated deleterious effects on product quality.

7 Environmental Protection
Examination of the quality of the water introduced by pump stations into streams is one of Conditions
the environmental conditions for a drainage system licence or permit.
Oil residues must be kept away from the pump system by installations such as sludge 17
traps and oil booms.
Settling tanks must also be included in the system to retain suspended material. In most
systems the water quality is tested regularly for suspended materials in accordance with
conditions of the respective permit.
The energy consumption of water drainage systems is directly affected by the length, Energy Consumption
radii and height profile of the pipeline as well as by the design of the pumps.
Decisions made during the extraction planning and pump station selection stages for a
well-chosen location can have a significant effect on the final energy consumption.
In centrifugal pumps the delivery head is of particular importance since an over-sized
pump leads to considerably greater power demand and therefore a decrease in the overall
efficiency.

8 Maintenance and Inspection

The operational status of water drainage systems must be checked regularly. In addition Inspection
to carrying out maintenance at the intervals specified by the manufacturer, the technical
functioning of the following items should also be checked
 float switch,
 strainer,
 pump impeller (indirectly via the pump pressure) and
 pipelines.
Maintenance intervals should be shortened during freezing conditions. This makes it pos- Freezing conditions
sible to detect and rectify damage to the system in good time. In some installations the
complete emptying of the system for freeze protection is a seasonal maintenance precau-
tion.
In pump systems corrosion is caused primarily by cavitation. In this case technical options Corrosion by Cavitation
should be implemented in accordance with the manufacturers recommendations.
Wear of pump impellers and housings may also be caused by a high proportion of sandy Wear Caused by
particles in the water conveyed. In order to minimize the amount of such material, the Particles

intake should be positioned at a sufficient distance from the sediment surface.

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 9 Questions on Course LB 1.2 Water Drainage Systems

9 Questions on Course LB 1.2 Water Drainage

Systems
You can test your knowledge by answering the following questions.

Question 9.0 A:
1. Which legal requirements is water drainage subject to?
2. What is the purpose of settling tanks?
3. What are separator systems?
4. What is the purpose of a swan-neck?
5. Which type of pump is mainly used in drainage systems?
6. What are the disadvantages of centrifugal pumps compared to reciprocating pumps?
7. What is understood by cavitation?
8. What measures can be taken against cavitation?
9. What special measures must be taken during pump operation in freezing condi-
18 tions?
10. Which special measures must be taken to protect pipelines against freezing?
11. Explain the two central components of a strainer.
12. What is the purpose of a water meter?
13. Name two key advantages of centrifugal pumps.
14. Briefly explain the operating principle of a centrifugal pump.
15. What is the purpose of a pipeline valve?
16. What is a pressure meter?
17. Name some of the points to avoid when designing pipe systems for water drainage.
18. What is the purpose of a filling connection?
Solutions see p. 19

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Solutions
Solution for 9.0 A:
1.  Water Resources Policy Acts of the respective coutries.
 State Water Acts passed by the Federal States or possibly provinces
2. The incoming run-off is subjected to preliminary cleaning in settling tanks where
dust and other suspended materials that are denser than water settle to the bottom.
Light materials remain on the surface of the water where they are prevented from
flowing away by the swan-neck run-off.
3. Separator systems are technical facilitiesfor removing contaminants from the in-
coming or in-situ water.
4. It prevents light materials on the surface of the water in the settling tank from flow-
ing away.
5. Centrifugal pumps
6. Centrifugal pumps are less efficient than reciprocating pumps and are not self-
priming. 19
7. The formation and abrupt collapse of vapour bubbles in pump systems.
8. Optimization of the conveying pipeline, influenced by pipeline length, radii and
total delivery head, taking into account the delivery head curve. Use of nickel
chromium steels in combination with an appropriate shape and surface quality.
9. Regular inspection and, in some cases, complete emptying of the systems
10. The lines must be either laid with freeze protection or it must be possible to com-
pletely empty the lines. Outlet devices are to be provided for this purpose at the low-
est points. Pipelines laid without frost protection must be either regularly flushed
or emptied during operation in winter.
11.  A screen prevents contaminants from being drawn in.
 A shut-off valve prevents the line from emptying.
12. Measuring water quantities for statistical purposes or to comply with official regu-
lations
13.  they convey liquid without fluctuations in pressure
 technically simple design
14. A rotating impeller draws in the liquid from the suction line, compresses it and then
forces it into the pressure line.
15. A pipeline valve is used to control distribution and direction in pipe systems.
16. Pressure manometer is a technical term for a pressure gauge.
17.  tight radii
 excessive increases in height
 excessively small pipeline cross-sections
 pipeline depressions that are not freeze-protected
 poorly accessible strainers
18.  A filling connection is used to fill the suction line with external water. This
opening is particularly important in pump types that are not self-priming like
e.g. centrifugal pumps.
Questions see p. 18

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Glossary
cavitation
The formation and abrupt collapse of vapour bubbles
cavitation corrosion
Destruction of pumps by the corrosive effects of cavitation
cavitation erosion
Destruction of pumps by high-speed jets caused by cavitation
centrifugal pump
Radial centrifugal pumps operate by the principle of suction, compression and transport. The central com-
ponent is the impeller. It is driven by an electric motor and runs in the liquid, mounted on a drive shaft. The
impeller draws in the liquid from the suction pipe and forces it into the pressure pipe. Liquid is prevented from
escaping at the rotating shaft by a seal.
characteristic curve
describes the relationship between pressure increase and output of a centrifugal pump
flow pumps
Type of pump that operates by the flow principle
impeller 21
Central component of a centrifugal pump that conveys the liquid from the suction side to the pressure side.
IP codes
Ingress Protection; gives the suitability of electrical equipment for various environmental conditions and the
protection of humans against potential danger when it is used.
1st number: type of protection against contact and foreign bodies
2nd number: protection against water
nominal output
Calculated output of a unit
output
actual volume conveyed
pipeline valve
System for controlling distribution and direction in pipe systems
positive-displacement pump
Self-priming pump type that operates with a vacuum
pressure manometer
Technical name for a pressure gauge
quarry bottom
The lowest point in a quarry
reciprocating pump
In reciprocating pumps a cylinder runs in a piston. When the piston moves upwards, the liquid is drawn in
underneath through an inlet valve. It is then ejected through the outlet valve. Manually operated reciprocating
pumps are particularly common in old wells.
separator system
Technical device that makes it possible to remove contaminants from incoming or in-situ water
shaft seal
Seal that prevents liquid from escaping at the rotating shaft of the pump.
spiral housing pump
Spiral housing pumps belong to the group of centrifugal pumps
strainer
Prevents contaminants being drawn into pump systems. A shut-off valve prevents the lines from emptying.
water meter
Device for measuring water volume
Water Resources Policy Act
The policy act, which regulates water resources, contains, inter alia, regulations on the protection and utilization
of bodies of surface water and ground water.

VDZ gGmbH
Research Institute of the Cement Industry
 Index

C
cavitation 6, 10, 12
cavitation corrosion 13
cavitation erosion 13
centrifugal pump 4
characteristic curve 10

F
flow pumps 5

I
impeller 6
IP codes 9

N
nominal output 9
22
O
output 9

P
pipeline valve 15
positive-displacement pump 6
pressure manometer 14

Q
quarry bottom 2

R
reciprocating pump 6

S
separator system 3
shaft seal 6
spiral housing pump 5
strainer 13

W
water meter 16
Water Resources Policy Act 1

VDZ gGmbH
Research Institute of the Cement Industry