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PHILOSOPHY OF OPERATION

Volume 1 Phases 1-1A

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Table of Content

PHILOSOPHY OF OPERATION 1

VOLUME 1 PHASES 1-1A 1

TABLE OF CONTENT 2

1.1 INTRODUCTION 4

1.2 Description & Design data 4 1.2.1 Inlet Tunnel: 4 1.2.2 Screening Shaft: 5 1.2.3 Pump Shafts. 6 1.2.4 Collection Chamber. 6 1.2.5 Flowmeter Chamber. 6 1.2.6 Distribution Chamber. 7

1.3 Contract Design Requirements 7 1.3.1 Flows/Velocities: 7

2.1 Inlet Tunnel: (process 1) 8

2.2 Mechanical Screens (process 2) 9 2.2.1 Function sequence of KUR Revolving Chain Screen 10 2.2.2 Function sequence of Double Spiral Conveyor (SF 420) 13 2.2.3 Function sequence Nogwash - Wash Press (NW 350) 15 2.2.4 Screen Trash evacuation to disposal 16 2.2.5 Mixers 16

2.3 Main Lift Pumps (process 1) 17 2.3.1 Automation (based on start/stop set points and flow regulation) 17 2.3.3 Storm weather or Tunnel emptying Scenario 24

2.4 Main Lift Pumps Suction & Delivery Valves (process 1) 25

2.5 Collection Chamber (process 1) 25

2.6 Flowmeter Chamber (process 1) 25

2.7 Main Distribution Chamber: 25

2.8 Odor Control System (process 5) 26 2.8.1 Terminodour system 26 2.8.2 System Operation 27 2.8.3 Extraction system and Biofilters 29

2.9 Ventilation & Water Chilling (process 6) 29

2.10 Power Supply (process 7) 30

3 APPENDICES 30

APPENDIX No.1 Hydraulic Profile Calculations Peak Flow 30

APPENDIX No.2 Hydraulic Profile Calculations Min Flow 30

APPENDIX No.3 Artelia Group Technical Memorandum Feb2012 Rev.0 30

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APPENDIX No.4 Hydraulic Profile Drawing 30

APPENDIX No.5 Flow Scheme Drawing 30

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1 INTRODUCTION, DESCRIPTION & DESIGN DATA

1.1 Introduction

The North Jeddah Main Lift Pump Station is designed to cater for an ultimate average design

flow of 750,000 m3/day of domestic effluent, with peaking factor of 1.5 times DWF, in 2

Phases with the current contract designed to cater for a design flow of 250,000 m3/day and

this operating scenario is based on the current proposed Phase 1 flows. This staged

construction is in compliance with Contract Specifications Volume-3, Section 01, Clause 2.1

and 3.1. and the System Operating Philosophy is in accordance with requirements of

Volume-7, Section 01, Clause 4.5 where applicable. Details of proposed operating levels and

flows for Phase 2 are also shown within the document. This document is generated based

on the following Documents:

o Final Hydraulic Report

o P&ID Drawings

o Hydraulic Flow Profile/Scheme

o HAZOP Study

The station comprises of the following: (Refer to Flow Scheme Section 3 Appendices)

1.2 Description & Design data

1.2.1 Inlet Tunnel: Sewage flows will gravitate via the inlet tunnel shaft (1B & 5B) wherein is located an

Actuated Penstock in each shaft to provide isolation of flows to the station during

emergencies. The control of these penstocks is automatic to close when a defined HHL (High

High Level) is reached in the shaft to protect downstream flooding of the station. Opening

sequence start command for the penstocks is undertaken manually, with staged opening in

an agreed stepped manner, to avoid jetting/surging in the system and following

recommendations of the HAZOP Study. The time settings is agreed with NWC Operation &

Maintenance to ensure no flooding of downstream facilities (North Jeddah WWTP) and is

envisaged that it will comprise a staged opening scenario with openings of approximately

100 to 200 mm in a timed sequence which shall be adjustable and this is documented during

the testing and commissioning stage.

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Nevertheless the as built situation of the tunnel between Shaft 1A and NJPS entry at Screen

shaft B3 is now fully different of the design profile. The new situation has now to integrate a

counter slope of 0.80 m located at recovery shaft N 2 (RShaft2) between shaft 2B ab 3B.

The main consequences are following:

o The slope between shaft 1A and RShaft2 is lowered from 1.4 mm/m to 0.7 mm/m,

but the shape of the invert generates a permanent storage with settlings of max 0,8

depth between 1A and RShaft2

o The slope between RShaft2 and the inlet of NJPS at the screen shaft B3 is increased

from 1.4 mm/m to 2.02 mm/m. The consequence is higher speed at B3 entry with

lower Water Level and control problem for the pumps operation. An operating

solution has been developed for solving this problem

o The frame basement of the Safety Penstock at Shaft 1B will be subject to fine sand

settlements up to 0.3 or 0.4 meters. This situation can prevent the safety penstock

from closing. An operating solution can solve this problem

1.2.2 Screening Shaft:

Sewage flows entering the screen shaft is split through 2 penstocks to either of 2 half's of

the screen shaft with each half capable of either feeding a dedicated pump shaft, in which

case cross over penstock at dividing wall is closed, or feeding the opposite pump shaft in

which case the cross over penstock is opened.

The screen shaft is provided with 2 complete screening, conveying and compacting systems

(1 for each line) for removal of all screenings above 20 mm in size. Screening duty operation

is in accordance with guidelines laid out to suit the various flows with a single screen in

operation during stage 1 flows and 2 units operational for future stage 2 flows as per

attached Table A. Nevertheless the number of running screens can be changed depending

on the acceptable clogging rate. The No of running screens depends on the incoming flow

and the delta (WL upstream and down stream of screen)

The volume below the screen channels level (-30,00) being constantly under water, is

permanently mixed by 2 mixers on each side (half shaft) in order to mitigate settlements

and gas production/release.

The screening plant is arranged for full automatic operation via the Screening Panel HMI,

controlled by ultrasonic level controls with 2 speed operation as detailed in philosophy of

operation detailed hereafter.

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1.2.3 Pump Shafts. Both pump shafts B1 & B2 are protected from flooding by 2 safety penstocks equipped with

balancing gates. The closing of these gates (if suction headers are in operation) is controlled

by a HHHL in shaft B3. The gates close only if Safety Penstocks in Shaft 1B and/or 5B are

closed AND HHHL in Shaft B3 is reached. HHHL value is near to coping level. Opening of this

safety penstock is performed manually applying special procedure.

Sewage flows is directed to either Pump Shaft 1 or 2 and each shaft is provided with 3

pumps operating as 2 duty with 1 standby controlled by levels in their respective screen

outlet chamber and/or in the Shaft B3 entry chamber, by use of Ultrasonic Level Controllers,

with back up level conductive type probes for both starting and to protect against dry

running of the pump units in case of failure of the primary ultrasonic controllers. The control

of the pumps can also run over time regulation in low levels taking in account the time out

of 20 minutes between stop/start of each pump in order to limit the number of starts per

hour (3 max). Operating flows and levels is in accordance with details defined in Table A

attached, as defined in the Final Hydraulic Report, to cater for range of flows for Stage 1.

Flows from each pump are measured to provide instantaneous flows and flow totalization.

We will see further that the total flow is used in the scenario 1A below for the flow

regulation.

In addition the operating scenario will also cater for tunnel emptying (closed for operational

need or storm water influent)

1.2.4 Collection Chamber. Pumped flows are discharged to the Collection Chamber from where they will gravitate to

the Main Distribution Chamber. The collection chamber is so designed to allow gravity

distribution to any of 3 discharge mains by a series of slide gates which allows for selection

of distribution mains and isolation of the chambers within the Collection Chamber by

opening and closing of the respective slide gates. These operations are undertaken manually

to cater for future increases in flows up to the ultimate peak design flow of 13.2 m3/sec and

additionally used for any planned maintenance works.

For tunnel emptying it is necessary to take 2 lines in operation. The opening/closing of the

dedicated penstock is automatic

1.2.5 Flowmeter Chamber.

Gravity flow rates in each distribution line is measured by Ultrasonic Flow Meters fitted in

each line to provide instantaneous flows and flow totalization and thus providing historical

data of the flows passing through the station.

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1.2.6 Distribution Chamber. Gravity flows is discharged to the Main Distribution Chamber from where they is evenly

split, by a series of adjustable overflow weirs (3 off), to each of the downstream Wastewater

Treatment facilities at the ultimate peak design flows. During the present scenarios (Stage 1

and 1A) the flows is directed to the existing Phase 1 WWTP via a single overflow weir and

weirs (2 off) for future connections to Phase 2 WWTP facilities is in a closed position.

Operation of the weirs is manually set.

For tunnel emptying it is necessary to take 2 lines in operation. The opening/closing of the

dedicated penstock is automatic

1.3 Contract Design Requirements

1.3.1 Flows/Velocities:

The contract of the station request the following specifications requirements:

o Design flow range of 1.45 m3/sec to 13.2 m3/sec when operating between 1 and 6

duty pumps in 2 Pump Shafts.

o Minimum flow velocity of 0.5 m/sec at all times to avoid solids settlement.

o To meet the requirements of the above minimum acceptable velocity a design flow

of 2.9 m3/sec (2 pumps operating at minimum flow of 1.45 m3/s) is adopted

specifications

Comments:

After study of all combinations of rotation speeds of the pumps and the consequences on

the downstream equipments so as the Airport 1 treatment plant and the velocities in the

downstream screens, channels and suction headers it appears that the minimum velocity of

0.5 m/s will have many adversely affects:

o Long stop periods over the day at actual and short term flow ( 150,000 to 200,000

m3/d), during these stop periods the velocity in any process stage is equal to ZERO

and the fine and microscopic sand in waste water will settle everywhere. These

settlements have thixotropic properties and cannot easily be resuspended in the

wastewater flow.

A permanent velocity in the system corresponding to a minimum flow which is

physically possible due to the minimum possibility of the VFDs for example

between 1.5 and 1.7 m3/s will permit to insure 0,31 respectively 0.35 m/s in the

suction header.

1.5 and 1.7 correspond to 168,000 respectively 190,000 m3/d with an observed peak

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factor of 1,3 on Airport 1 WWTP this hypothesis matches the actual and short

term situation.

o Mecanical and electrical incidents on the pumps

o Energy Efficiency Factor is very low

o Safety: if 1 pump is out of service there will be no internal pumping safety in 1 one

shaft and needs to change the duty shaft, which should be avoided.

For these reasons we advise and propose to implement following Philosophy for the

pumping :

Keep always 1 pump operating until low level (or stop level)is reached. Take 2nd pump into

operation if pump 1 is on max flow and level still raising. Pumping flow can be adjusted

taking in account table A

2 PHILOSOPHY OF OPERATION A said above, the philosophy of operation had to, and has been reviewed in order to

manage the new as built situation in the tunnel, and also the necessity to avoid pump stop:

The incoming water levels have been compensated in order to mitigate the high water

speed. The type of the compensation which has been fixed is linear between the +0.30 (WL

= 0.48 + 0.30 =0.78) at 1.45 m3/s flow up to +0.72 m (WL = 1,48 + 0.72 = 2,20) at 13.2 m3/s

The corresponding speeds are decreased from 1.86 m/s to 0.93 m/s and 3.43 m/s to 2.08

m/s. Now the incoming speeds are compatible with good practice in pumping station

operation

The new control/regulation of the pumping integrates as well the start/stop set points of

the pumps up to 6.6 m3/s (3 pumps at 100% flow) as the flow/frequency

adjustment/regulation in order to adapt the flow to the theoretical compensated WL in

the inlet of B3 (Table A)

The previous developed scenario 1-1A based on level regulation is obsolete and is deleted.

The scenario 2 based on flow regulation only is deleted

2.1 Inlet Tunnel: (process 1)

Sewage flows will gravitate via the inlet tunnel (1B to 5B) wherein are located actuated

Penstocks to provide isolation of flows to the station during emergencies. The control of this

penstock is automatic to close (closing time around 2mn) when a defined HHL (HIGH HIGH

LEVEL) is reached in the shaft to protect downstream flooding of the station.

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The needed energy to operate these 2 safety penstocks has been specially secured:

Shaft 5B

2 SCECO sources + autonomous internal oil pressure tank permitting 1 complete cycle

closing + opening for penstock in 5B. (Mainframe and balancing gate closure and opening

times: 2 minutes each)

Shaft 1B and Shaft 5B

2 Generators thereof 1 stand-by + autonomous internal oil pressure tank permitting 1

complete cycle closing + opening for Penstock in 1B. (Mainframe and balancing gate

closure and opening times: 2 minutes each)

The closing command signal comes from level validated by HHL from B3 Shaft meter with

report to SCADA. The local automation is assured by local PLCs connected to SCADA

Due to the deviation in the as built profile of the tunnel the excercise (Level 3 weekly)

operation of the Safety Penstock in Shaft 1B is modified as follows: when closing the

Penstock at average flow (between 2.2 m3/s and 2.4 m3/s , there has to be a stop at 90%

from the top or 10% opening of the diameter (0.35 to 0.40 cm) in order to flush the

settlements on the bottom of the penstock(Flushing Velocity in the restricted section: 4m/s

at 2.2 m3/s 1 pump full flow). After the flushing time out (to be set) resume the exercise.

2.2 Mechanical Screens (process 2)

The machine technology consists of:

6 pcs Revolving Chain Screen, type KUR

2 pcs Double Spiral Conveyor, type 420

4 pcs Wash Press, type NW 350/650

In terms of process engineering the machines are split into 2 lines. In the course of this

description only Line 1 is illustrated. This description can be fully applied to Line 2 as both

lines are completely identical i.e. comprising of 3 screens with respective conveyors and

compactors.

Line 1:

3 KLR revolving chain screens convey the screened material into the downstream double

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spiral conveyor which - depending on the setting of the manually operated hopper flap -

transports the material into one of the two wash presses.

Line 2:

Identical to Line 1.

Automatic Control from Local HMI:

Automation of the plant, (Line 1 and 2), which is set up via the Screening Panel HMI, is

effected via a programmable logic controller from Siemens, type S7-300. All process-

relevant parameters (filling levels, times and counters) are visualized by means of a

monochrome 5.7 touch panel, type KTP 600 from Siemens. All rated and actual values can

be read and set via this touch panel and so be adjusted or altered according to the operating

conditions. Therefore, no PLC programmer is required for optimizing the process sequences

to the local circumstances and conditions.

2.2.1 Function sequence of KUR Revolving Chain Screen

The KUR Revolving Chain Screen is equally suited as coarse screen as well as fine screen in

order to reliably remove large loads of contaminants. Its simple and rugged design

combined with modern construction and production technology ensure high reliability and

long service life.

Fundamentally, the rotary chain screen consists of two drive chains with one or more

cleaning elements, the sprocket wheels on the drive shaft as well as the bottom guide

sprocket station, a guide on each side, the drive unit with overload protection, the apron

with chute and the bar rack. The complete unit can be inserted into the screen construction

without any recesses which reduces the construction costs and enables subsequent

installation of the unit into existing structures trouble-free.

The cleaning elements which are fixed to the revolving chains mesh into the bar rack and in

doing so convey the screenings up to the discharge chute. An automatically operated

stripper shifts the screenings across the chute into the provided double

conveyors/compactors.

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The defined philosophy of operation, viz differential level control and 2 speed operation will

automatically cater for varying degrees of screenings encountered as a result of varying

flows and amounts of debris and thus providing optimum operating conditions at all times.

A manually commanded reverse operation of the screens permits to unblock the screen(s) if

necessary.

The screening plant operates independently of the pumps with a purpose to provide

screening of the incoming wastewater and thus protection for the pumps and thus the

differential control is applicable overall operating levels within the screen channels

independent of pump operation.

During Stage 1 a single duty screen is operated, in the selected line, and duty rotation is

arranged automatically on a daily basis to provide flushing of any accumulated solids

upstream of non operating units. The respective penstocks, upstream and downstream of

the screens is closed on the duty unit and opened on the selected changeover unit

automatically at the same time. Nevertheless it may be necessary that 2 screening channels

have to be operated in case of high inflow of trash, (for example after a longer period of

sewerage storage in the tunnel and/or storm water inflow (see FHR p22). This can also be

the case in Phase 1A. It has to be noted that the opening/closing time of the up and

downstream penstocks of the screens is around 15 min

2.2.1.1 Water level difference (differential level, speed 1)

Each of the 3 KUR Revolving Chain Screens is equipped with a pole-changing drive and thus

two rotational speeds. Depending on the water level in front of and behind the screen, it is

operated at the first or second rotational speed.

An ultrasonic sensor is installed in front of and/or behind each screen in order to detect the

filling levels in front of and behind the screen. The respective filling level is transmitted via a

4-20 mA signal to the automation system. At this point the differential level is calculated

(level in front of the screen - level behind the screen) and visualized via touch panel in the

switch cabinet door and in the hydraulic profile screen.

The exact level differential is monitored during commissioning to gauge optimum level;

however this is expected to be in the range of 150mm (low differential) to 300 mm (High

Differential). Comment: the nett value of WLC due to clogging of the screen can be

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calculated depending on flow or recorded as a table in PLC

WLC = WL WLHEADLOSS

This could be useful for high flows, to avoid permanent operation of the screens

As soon as the specified limit value for "differential level ON" is exceeded, the respective

screen will start at the first rotational speed. When the differential level drops below the

specified limit value for "differential level OFF", the screen will stop after an adjustable run-

on time.

2.2.1.2 Maximum water level (speed 1)

When via ultrasonic sensor the specified limit value for "max. Water in front of screen ON" is

exceeded; the screen will run at the first speed until the level in front of the screen falls

below the specified limit value of parameter "max. Water in front of screen OFF". Once the

water has fallen below the limit, the screen will stop again after a run-on time.

2.2.1.3 Water level difference and maximum water level (speed 2)

When the level control detects a differential level and maximum filling level in front of the

screen (parameter "differential level ON" and parameter "max. Water in front of screen ON"

are exceeded), the screen will start at speed 2. The screen is operated at speed 2 until no

differential level and no maximum filling level is detected in front of the screen (parameter

"differential level OFF" and "max. Water in front of screen OFF" has fallen below).

2.2.1.4 Maximum standstill (speed 1)

If none of the turn-on conditions described in Point 2.2.1.2. - 2.2.1.3. apply, the respective

screen is activated for an adjustable running time after a maximum standstill period has

elapsed.

2.2.1.5 Local operator unit of KLR Revolving Chain Screen

Each screen is equipped with a local control device. The local control device has four

installation points which are allocated as follows:

Position 1: Operating mode selector switch (key switch) Selection of the operating mode in

which the respective screen is to be operated.

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Automatic mode (Point 2.2.1.1 to 2.2.1.4)

0 (off)

Manual mode (at speed 1)

Position 2: Pushbutton which is used to switch on the respective screen in Jog mode at

Speed 1 (Manual operation).

Position 3: Pushbutton which is used to switch on backwards the respective screen in Jog

mode at Speed 1 (Manual operation).

Position 4: Emergency-Off button which, when operated, stops the complete plant (Line

1+2). This message must be acknowledged by means of a luminous pushbutton on the

switch cabinet door before the machines can be reactivated.

2.2.1.6 Overload KUR Revolving Chain Screen

Each screen is provided with a proxy-switch which detects whether the respective screen

has been overloaded. If an overload signal has been triggered, the respective screen is

stopped. A luminous pushbutton in the switch cabinet door indicates which screen was

switched off. The malfunction must be rectified and the overload message acknowledged

before the screen is ready for operation again.

2.2.2 Function sequence of Double Spiral Conveyor (SF 420)

The SF Double Spiral Conveyor is fitted with two shafts-less spirals. The geometry of the

spirals, i.e. the pitch, diameter and cross-section of the spiral profile, are specified in

accordance with the medium which is to be conveyed and the operating conditions.

The conveyor spirals have only one bearing point which is located in the region of the drives.

In the trough the spirals form a linear load and are guided through its geometry.

The shaft-less spirals are able to conveyor dry, moist, wet, paste-like, sticky, powdery,

coarse or abrasive material.

In the feeding hopper the SF Double Spiral Conveyor is equipped with a 2-way hinged flap.

By selecting the position of the hinged flap you specify which of the two conveyors is to be

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fed with solid matter. The hinged flap must be adjusted manually with a lever.

2.2.2.1 Hinged flap

Two magnetic switches are used to monitor the position of the hinged flap. Depending on

the position of the flap, one of the two spiral conveyors is fed with material from the

upstream screen. By means of the flap's position you see which spiral conveyor must be

activated and thus, which of the two downstream wash presses is to be fed.

2.2.2.2 Double Spiral Conveyor

When one of the screens described in Point 2 is activated, the respective spiral of the SF

Double Spiral Conveyor starts depending on the position of the hinged flap. As soon as the

SF Double Spiral Conveyor no longer receives material from any of the upstream screens,

the respective spiral switches off after a specified run-on period.

2.2.2.3 Local operator unit of SF Double Spiral Conveyor

Each Double Spiral Conveyor is equipped with a local control device. The local control device

has four installation points which are allocated as follows:

Position 1: Operating mode selector switch (key switch) Selection of the operating mode in

which the respective double spiral conveyor is to be operated.

Automatic mode (Point 3.2)

0 (off)

Manual mode

Position 2: Pushbutton used to activate the 1. Spiral forwards in Jog mode (Manual

operation).

Position 3: Pushbutton used to activate the 2. Spiral forwards in Jog mode (Manual

operation).

Position 4: Emergency-Off button which, when operated, stops the screening plant (Line

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1+2). This message must be acknowledged by means of a luminous pushbutton on the

switch cabinet door before the machines can be reactivated.

2.2.3 Function sequence Nogwash - Wash Press (NW 350)

The Wash Press is fed by the spiral conveyor described in Point 3 and works by means of a

screw conveyor. The material supplied in the feeding zone is collected by the screw

conveyor and transported towards the pressing zone. The slotted base of the conveying

zone enables static drainage of the medium which is being conveyed. In the pressing zone

the material is compacted, dewatered and pressed through a friction pipe.

2.2.3.1 Activation via add-up timer (intermittent operation)

The running time of the upstream screen is recorded for the activation of the wash press.

When exceeding the set value, the discharge spiral of the wash press switches on at

intervals and a washing period is activated. During this time the discharge spiral also

operates at intervals. The discharging intervals can be adjusted independently. Wash water

is supplied via a solenoid valve during the intermittent break time. With an additional time

element you can additionally shorten the duration of the supply in order to prevent an

overflow of the hopper.

2.2.3.2 Activation via light sensor

In order to prevent the hopper of the wash press from overflowing in the case of

extraordinary circumstances, the filling level in the screenings hopper of the wash press is

monitored by a light sensor and used as additional start signal.

The operational mode and dependencies are in principle as described in 4.1. Upon

exceeding a limit value of e.g. more than 60 s (parameter "switch-on delay emergency

discharge (without washing)"), an emergency discharge operation (continuous operation

without flushing) is initiated. When no longer at limit value, deactivation after run-on time

for emergency discharge has elapsed (parameter "run-on time emergency discharge

(without washing).

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2.2.3.3 Local operator unit of Nogwash - Wash Press

Each Wash Press is equipped with a local control device. The local control device has four

installation points which are allocated as follows:

Position 1: Operating mode selector switch (key switch); selection of the operating mode in

which the respective wash press is to be operated.

Automatic mode (Point 4.1 - 4.2)

0 (off)

Manual mode

Position 2: Pushbutton which is used to activate the discharge spiral forwards in Jog mode

(Manual operation).

Position 3: Emergency-Off button which, when operated, stops the complete screening

plant (Line 1+2). This message must be acknowledged by means of a luminous pushbutton

on the switch cabinet door before the machines can be reactivated.

2.2.4 Screen Trash evacuation to disposal

The evacuation of screen trash trough the caddies and freight lift to the ground level and to

the solid waste truck is fully manual so as the return and the washing of the containers to

coping level and repositioning under the Nogwash Wash Press

Check up charging the batteries of the caddies are O&M operations.

2.2.5 Mixers

The volume underneath the slab of screening channels at -30m (around 4000 m3 on each

line) is equipped with two mixers (each line) these mixers are working in an autonomous

way and are not linked to any external device. The control is local with back information to

the SCADA. They work only if the concerned volume is flooded.

.

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2.3 Main Lift Pumps (process 1)

2.3.1 Automation (based on start/stop set points and flow regulation) Rem. See generalities and justifications under chapter 2 Philosophy of Operation

During the normal plant operation the main lift pumps are left in automatic mode and

are automatically controlled by ultrasonic level controllers with automatic level control

arranged for starting and stopping and additionally providing flow variation by use of the

pump Variable Speed Drives. At the selected start levels, in accordance with Table A

(Developed based on pump system curve X-35678-1A and in Appendices Section we have

included the tested pumps performance curves wherein it can be seen that tests match with

the mentioned curve), the duty pump number 1 will start and the pump flow rates is

variable to maintain levels against range of flows by adjustment of the Pump Variable Speed

Drives controlled by the ultrasonic sensors. refer to Table B for details, in the system and

equating to pump operating frequency of 55 Hz (See attached Pump System Performance

Curve). The Ultrasonic level controllers is fitted in each outlet chamber of the screen shaft

and is set up to either work as a dedicated controller for their respective connecting pump

shaft or to be selected to allow control in their opposite pump shaft. The sequence of

operation is as follows:

On failure of any duty pump the standby pump no. 3 is automatically come on line following

the sequence as outlined above. All levels for starting and stopping are fully adjustable in

accordance with selected levels to cater for any ageing of the incoming tunnel and the meet

the optimum inflows to the station as and when the design flows come on stream.

The control set up will have additional back up conductive level protection to start & shut

down pumps in case of any malfunction of the primary ultrasonic level controllers utilizing

conductive type level electrodes in each outlet chamber to ensure no dry running of the

pumps can occur.

Start Stop cycles will additionally have an adjustable time period between start/stop cycles

of approx. 20 minutes to avoid surges in the outfall system.

The following will apply:

In all cases (phase 1) only 1 screen is on duty

Levels are in accordance with tabulated hydraulic profile as per Table A hereunder.

Start Stop cycles will additionally have an adjustable time period between start/stop cycles

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of 20 minutes minimum.

Levels are selected to provide optimum flow velocities in screen approach channels as

determined by the tunnel slope.

Minimum pump operating frequency of 55Hz would equate to operating level for flow of 1,5

m3/sec (-28.44) and maximum design capacity of 4.4 m3/sec (2 pumps full flow) would

equate to level of -27.94

HHL alarm would be set at -26.33 at which level the inlet penstock would close.

LLL at which point pumps cut out would be set at -30.00

Sequences:

o Pump no1 operates constantly, start at minimum flow at WL -28.38, increases the speed

of VFD when flow increases up to 2,2 m3/s, following the flow/height table A up to

-28.16 m (WL 2.9 ) at maximum flow

o If WL decreases go to yellow column and speed will decrease down to stop level ( -28.

43), if WL (re)increases in this sequence, increase speed/flow etc..

o If WL reaches -28.16m and continues raising then start pump no 2 at min flow and

decrease pump no 1 to min flow , so total pumped flow = 2.9 m3/s

o Increase both pumps until WL decreases or until WL 4.4 is reached

o If WL 4.4 is reached AND is decreasing, decrease frequency of VFDs and follow flow down

to WL 2.9, if WL continues decreasing continue pumping pump 1 and pump 2 down to

stop level of Pump 2 and stop pump 2, follow the flow with pump 1 (up or constant to

stop level of pump 1)

Sequence for start pump 3

o Needs anticipated/permanent authorization to increase the flow up to 6.6 m3/s

coming from external authority (NWC Operation Division, Airport WWTP..) when WL

reaches 28.06

o Continue pumping pumps 1 & 2 up to WL8.8

o Start pump no 3 until WL decreases, stop pump 2 & 3 at stop level P 2&3 (-28.30)

Continue following Flow/Level with pump no1 until stop or WL increases again

Tunnel emptying:

o Fix the authorized tunnel emptying flow and WLEmptying Tunnel

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o Start and ramp up to the desired flow

o Regulate Balancing gate and Main gates so that the current WL will remain

constant (+/- 5 cm) around WLEmptying Tunnel

o WLEmptying Tunnel

o Must be lower than safety penstocks closing level

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Table A

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North Jeddah Pump Station - Summary of Flow Conditions Approach Pipe/Tunnels Table B 2500 mm Suction Pipe

Stage 1 - B2 Shaft Only in Operation 1 Pump Min Flow 1 Pump

2 Pumps Min Flow 2 Pumps 3 Pumps Comments

Suction Size Dia. mts 2.5 Velocity for single pump operation

not acceptable and control set to allow for minimum of 2 pump operation

Q per Shaft m3/sec 1.45 2.2 2.9 4.4 6.6

Velocity m/sec 0.30 0.45 0.59 0.90 1.34 Stage 2 - B1 & B2 Shafts In Operation 4 Pumps 5 Pumps 6 Pumps Comments Suction Size Dia. mts 2.5

Velocities for range of flows specified acceptable Q per Shaft m3/sec 4.4 * 6.6

Velocity m/sec 0.90 ** 1.34 * One shaft with 2 pumps and 2nd shaft with 3 pumps and Q of 4.4 and 6.6 m3/sec respectively ** Velocity of 0.9 m/sec for 2 pump operation and 1.34 m/sec for 3 pump operation Acceptable Velocity for microscopic and very

fine sand Acceptable Velocity

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2.3.3 Storm weather or Tunnel emptying Scenario

The site hydraulical, electromechanical and meteorological reality will bring a lot of

exceptional events which lead to storage of the sewage and/or rain water in the

tunnel.

Storm weather or Tunnel emptying Scenario covers these events like running the

pumps when penstocks 1B and/or 5B were closed (incident or storm event..) or

regulating the flow.

Such operation control is mandatory because stored flow can not just be sent to

the NJPS without any control. The aim of this Scenario is to transfer the stored

water (Sewerage or Storm Water) with a preset (or a variable preset) value of the

flow so that finally it can be treated correctly and discharged correctly to the sea

outfall.

In the actual layout of NJPS Phase 1 and 1A, NJPS can be operated up to up to 6.6

m3/s through Scenario 1 or 2 in one Pump shaft (B1 or B2). Exceptionally the

pumped flow can be increased up to 8.8 m3/s in two shafts.

In all cases the values of possible pumped flow has to be controlled and pre-

authorized by others

In this Scenario the Control of the pumps is operated on preset and pre-authorized

flow values depending on the stored volume/level in the tunnel, and regulation of

the incoming flow through action on the 1B and/or the 5B tunnel penstocks by

monitoring the level in the pump shaft(s) and the tunnel (shaft 5B).

In summary the steps are:

o Evaluation of the additional stored volume in the tunnel

o Evaluation of the normal incoming flow through statistics at the give time

o Set the flow value

o Start emptying the tunnel (manual start procedure of emptying through

balancing gates)

o Control and adjusting the opening of the penstocks on a give preset WL in

pump sump(s)

The incidence on all upstream (Penstocks settings, no of duty screens, no of Pump

Shafts, no of diameter 2000 between CC and MDC have to be taken in account and

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set on correct position on site before starting.

2.4 Main Lift Pumps Suction & Delivery Valves (process 1)

During the normal plant operation the main lift pumps valves are left in automatic

mode and will be arranged to be normally open at all times. As the system is

derived from static head there is no requirement for opening valves on pump start

as the system is non-overloading over the complete range of pump operation. In

addition on pump stop signals there is no requirement to close the delivery gate

valves. Pump starting is undertaken only when Valve Fully Open signal is in place.

2.5 Collection Chamber (process 1)

During the Stage 1/1A normal plant operation, a dedicated collection tank

chamber is utilized, corresponding to the respective gravity main in use, and the

outlet penstock from this chamber will remain open, with all other chamber

penstocks closed. Normal operation of the penstocks is undertaken manually to

cater for any planned maintenance and change over from the selected gravity

main.

In the alternative Phase 1A the dedicated compartment of the CC must be open if

necessary.

2.6 Flowmeter Chamber (process 1)

During the Stage 1 and 1A normal plant operation, a dedicated flow meter is

utilized, corresponding to the respective gravity main in use to monitor and record

total flows.

The other flow meters would only be utilized in case of changeover of the gravity

main for maintenance purposes.

2.7 Main Distribution Chamber:

During the Stage 1 and 1A normal plant operation, a dedicated distribution inlet

penstock would remain open, corresponding to the selected Collection Tank

chamber/gravity line in use and the other 2.penstocks would remain closed.

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Normal operation of the penstocks is undertaken manually to cater for any

planned maintenance and change over from the selected gravity main.

The dedicated outlet weirs feed to the existing Stage 1 WWTP would be set open

and the other weirs would remain closed at all times.

2.8 Odor Control System (process 5)

The Odor Control System is composed of:

The Terminodour system producing ionized air and which is injected above the

coping level -21.20 m

A collection pipes network below the coping level -21.20 which works at a

differential pressure of around 100mm Water Column and sends the mixed gases

(Ionized air + gases) from the confined volume to the ground level. This system is

equipped with fans and explosion relief valve(s)

The treatment is performed by filters (Biological Filters) before rejecting to the

atmosphere. The filters are equipped with recirculation pumps automatically

controlled.

The control of the extraction system is in conjunction with the ionization to ensure

differential air pressure between injection and gas extraction.

2.8.1 Terminodour system

The Terminodour positive pressure Ionised air odour control system supplied and

installed at the North Jeddah Pump Station is designed to reduce/neutralise the

internal odorous air and improve the internal air quality of the screen shaft cover

level. The Terminodour units are installed above ground in the Equipment

Building. Fresh air passes into the equipment building via weather louvers

mounted within the building superstructure, the fresh air is drawn into the

operational AHU through a weather louver and particulate filter.

The AHUs are configured to operate as two duties AHUs and one standby AHU.

Each AHU incorporates washable filters with a Magnahelic Gauge fitted across the

filter to monitor the condition. The air then passes across thirty two ionisation

units (sixteen in each AHU) into a fan chamber. The treated air then flows through

the operational fans each fitted with a Differential Pressure Switch (DPS) to

monitor air flow and initiate an alarm if no flow is detected; the standby unit will

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then be operated if a duty unit fails. After the Ionisation Section the air then passes

into the main discharge duct. The discharge duct descends to level -21.2m AOD

and is branched off to serve the various areas, with volume control dampers

(VCDs) to control the volume of air being distributed on each duct.

The Combined Air Volume being delivered by the two duty Terminodour Units is

12.38m3/s.

The ionization process on this site is designed to permanently operate to ensure

that all odours are eliminated (i.e. 24 Hrs. / day).

2.8.2 System Operation

The Terminodour positive pressure Ionised air odour control system supplied and

installed at the North Jeddah Pump Station is designed to reduce/neutralise the

internal odorous air and improve the internal air quality of areas within the shaft

at lower levels. The Terminodour unit is installed outside the shaft in a separate

building; the air is drawn through inlet filters (which have a Magnahelic Gauge to

monitor for blockages), the air is then drawn into a common fan chamber

containing a duty only fan which has a Differential Pressure Switch (DPS) to

monitor airflow. An intermediate duct is installed between the fan section and the

ionisation section containing 16No. Ionisation units per unit. The ionised air then

flows into the discharge duct serving the screen shaft cover.

The system is designed to operate in Automatic mode continuously.

Auto operation

1. Select Duty Fans.

2. Switch auto / off / manual selector switch to auto.

3. Switch Ionisation auto / off / manual selector switch to auto.

4. The ionisation system will then be ready to start.

5. The Duty Fans will start when the fan auto / off/ manual switch is selected in

Auto, if required an enable signal is to be given by ops. The relevant fan running

lamp is illuminated.

Note: Both switches (Ionisation and Fans) must be in auto for the complete

ionisation system to operate. A de-bounce timer is required to start the duty fan.

6. The supply differential pressure switch is to prove airflow (N/O contacts close

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and N/C contacts open when pressure increases). On confirmation of airflow a 30

second timer starts and allows the system to be purged prior to the Ionising units

being energized.

7. The Ionising units running indication lamps are illuminated.

Note: The Ionising units to switch off as soon as airflow is lost. A de-bounce timer

is required as weather conditions may affect the DPS.

8. Each ionising unit is to be monitored by a separate undercurrent monitor, fuse

failure or tube failure to initiate failed indication lamp (Range required on

undercurrent monitor 50 300 mA).

9. When the auto / off / manual selector switch is removed from auto the system

will stop or if a stop signal is received from ops.

Fault conditions.

1. Soft Start / O/L failure fan 1, fan 2 or fan 3.

a) Differential pressure switch drops out and switches off Ionisation units

b) Duty fan trip lamp illuminates on appropriate fan starter section, HMI will show

failed fan indication and alarm via Ethernet to Telemetry/SCADA

c) Duty fan stops and running lamp goes out along with running indication on HMI.

d) Standby fan starts running lamp illuminates and running indication shown on

HMI.

e) On confirmation of airflow the 30-second timer will run and allow the system to

be purged prior to the Ionisation units being re-energized.

f) The Ionisation units running indication is shown on HMI.

Note: If Standby Fan fails or is already isolated the Ionisation Units will switch off

and that system will stop.

2. Airflow failure (Start-up)

a) Differential Pressure Switch fails to make. (Ionisation Unit timer does not start)

b) Airflow failure indication is shown on HMI and alarm via Ethernet to

Telemetry/SCADA.

c) Duty fan stops and running lamp goes out with fan trip failure also shown on

HMI.

d) Standby fan starts running lamp illuminates and running indication shown on

HMI.

e) On confirmation of airflow the 30-second timer will run and allow the system to

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be purged prior to the Ionisation units being re-energized.

f) The Ionisation units running indication is shown on HMI.

Airflow fails for less than 10 seconds

a) If DPS fails for less than 10 seconds and re-establishes airflow whilst unit is in full

operation the ionisation units will continue to run.

Airflow fails between 10 seconds and 30 seconds

a) If DPS fails for more than 10 seconds then the ionisation units will stop.

b) If DPS then re-establishes airflow within 30 seconds the 30 seconds purge timer

will start and at the end of this period if airflow is still made the ionisation units

will start.

Airflow fails after 30 seconds

2.8.3 Extraction system and Biofilters The Biofilter extraction odour control system at the North Jeddah Pump Station is

designed to designed to cater for removal and treatment of gases and carried over

odour air from below screen coping level. The system will be arranged for

automatic operation in conjunction with the Ionization system to ensure a

negative pressure is generated at all times to provide a downward path of air from

above screen coping level. The control will be linked to the ionization system to

ensure extraction rates always exceed the flow rate of ionized air.

The system is designed to operate in Automatic mode continuously.

2.9 Ventilation & Water Chilling (process 6)

HVAC is composed of different systems and components and implemented in

different locations:

AC Windows Units

AC Split Units

AC Roof Mounted Packages

Water Chiller systems

Ventilation wall mounted

Ventilation Packages

These systems are locally controlled and some are centrally surveyed for alarm

purpose for example. Nevertheless efficient ventilation and cooling in buildings

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containing MV and LV are critical and essential for the good operation and for

the life time of equipments. Therefore a special care has to be given to this

process.

2.10 Power Supply (process 7)

The station is designed to be feed by SCECO power with twin power supplies,

duty and standby, permanently connected to each set of main switchgear. In

case of power failure there are dedicated standby generating sets permanently

connected to each set of main switchgear, arranged for automatic starting and

load distribution via an ATS to run the station. On power failure the pumps and

all associated equipment is automatically restarted in a staggered rotation to

allow the complete station to function.

3 APPENDICES

The appendices as referred to below are attached to the Final Hydraulic Summary Report and

can be accessed via that document.

APPENDIX No.1 Hydraulic Profile Calculations Peak Flow

APPENDIX No.2 Hydraulic Profile Calculations Min Flow

APPENDIX No.3 Artelia Group Technical Memorandum Feb2012 Rev.0

APPENDIX No.4 Hydraulic Profile Drawing

APPENDIX No.5 Flow Scheme Drawing

Control Philosophy VOL1 Phase 1-1A-Version 3.pdfPHILOSOPHY OF OPERATIONVolume 1 Phases 1-1ATable of Content1.1 Introduction1.2 Description & Design data1.2.1 Inlet Tunnel:1.2.2 Screening Shaft:1.2.3 Pump Shafts.1.2.4 Collection Chamber.1.2.5 Flowmeter Chamber.1.2.6 Distribution Chamber.1.3 Contract Design Requirements1.3.1 Flows/Velocities:2.1 Inlet Tunnel: (process 1)2.2 Mechanical Screens (process 2)2.2.1 Function sequence of KUR Revolving Chain Screen2.2.2 Function sequence of Double Spiral Conveyor (SF 420)2.2.3 Function sequence Nogwash - Wash Press (NW 350)2.2.4 Screen Trash evacuation to disposal2.2.5 Mixers2.3 Main Lift Pumps (process 1)2.3.1 Automation (based on start/stop set points and flow regulation)2.3.3 Storm weather or Tunnel emptying Scenario2.4 Main Lift Pumps Suction & Delivery Valves (process 1)2.5 Collection Chamber (process 1)2.6 Flowmeter Chamber (process 1)2.7 Main Distribution Chamber:2.8 Odor Control System (process 5)2.8.1 Terminodour system2.8.2 System Operation2.8.3 Extraction system and Biofilters2.9 Ventilation & Water Chilling (process 6)2.10 Power Supply (process 7)3 APPENDICESAPPENDIX No.1 Hydraulic Profile Calculations Peak FlowAPPENDIX No.2 Hydraulic Profile Calculations Min FlowAPPENDIX No.3 Artelia Group Technical Memorandum Feb2012 Rev.0APPENDIX No.4 Hydraulic Profile DrawingAPPENDIX No.5 Flow Scheme Drawing