Reverse osmosis Process with Modified V-SEP technology

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Design and Analysis of Industrial
Reverse Osmosis (RO) Plant
By
Sagar P. Joshi [100460119009]
Morvin H. Patel [100460119019]
Rushi J. Patel [100460119031]
Kishan K. Patel [100460119014]
Team ID : 130008334
Guided By
Mr. Saiyd Soyeb
Asst. Professor
Mechanical Department
Universal College Of Engineering
And Technology
Ahmedabad
Mr. Chetan Pandya
Project Engineer
ADI Finechem Ltd,
Chekhla-Sanand Highway.
A project report submitted to Gujarat Technological University
In partial fulfillment of the requirements for the Degree of Engineering
In Mechanical
May 2014
DEPARTMENT OF MECHANICAL ENGINEERING
UNIVERSAL COLLEGE OF ENGINEERING AND TECHNOLOGY,
AT: MOTI BHOYAN, GANDHINAGAR

Design & Analysis of Industrial R.O Plant GROUP NO- F7
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CERTIFICATE
This is to certify that work embodied in this entitled ―Design & Analysis of
Industrial Reverse Osmosis (RO) Plant‖ was carried out by Sagar Joshi,
Morvin Patel, Rushi Patel, Kishan Patel at Universal College of Engineering
and Technology, AT: Motibhoyan, Gandhinagar. For partial fulfillment of B.E.
degree to be awarded by Gujarat Technological University. This work has been
carried out under my supervision and is to my satisfaction.
Date:
Place:
DEPARTMENT OF MECHANICAL ENGINEERING
UNIVERSAL COLLEGE OF ENGINEERING & TECHNOLOGY
AT: MOTI BHOYAN, GANDHINAGAR
Mr. Saiyd Soyeb
Asst. Professor
Mechanical Department
Universal College Of Engineering
And Technology
Ahmedabad – 380 015
Mr. Chetan Pandya
Project Engineer
ADI Fine chem Ltd,
Chekhla-Sanand Highway.
Mrs. Mittal D. Patel
H.O.D. Mechanical Department
Universal College of Engineering
And Technology
AT: Motibhoyan, Gandhinagar

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Acknowledgement
With a sense of gratitude and respect we would like to extent my heartiest thanks to all those
who provide a help and guidance to us during our college period. It was a pleasant and highly
inductive experience to work for project on “DESIGN & ANALYSIS OF INDUSTRIAL
REVERSE OSMOSIS (RO) PLANT”.
We wish to express our sincere gratitude to Dr. N.K. Sherasia, principal and Mrs. Mittal D.
Patel, HOD of mechanical department of Universal College of Engineering & Technology.
We sincerely thank to our internal project guide Mr. Saiyd Soyeb, Asst. Professor of
mechanical engineering department for guidance and encouragement in carrying out these
project work.
We also wish to express our sincere gratitude to the official and other staff members of ADI
FINE CHEM LTD, who rendered their help during the period of our project work. Our
special thanks to Mr. Chetan Pandya, chief project engineer of the company for their kind
co-operation and always to be ready for providing the best instruction and guidance to do
work better.
Last but not the least to avail our self for this opportunity, express a sense of gratitude and
love to our friends and our beloved parents for their manual support, strength, help and for
everything.
Joshi Sagar P. _______________
Patel Morvin H. _______________
Patel Rushi J. _______________
Patel Kishan K. _______________

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Abstract
Water purification system for R.O plant is planted in a leading chemical company
which produce soya fatty acid, monomer fatty acid, dimmer fatty acid, distilled fatty acid,
glycerin etc. In R.O plant high pressure pump, filters, membranes are used. Water passes
from pump via filter to series of membranes. In these two membranes water passes one after
another. For purification of water a pressure difference is required. In these membranes
required pressure difference acts critically. If pressure difference between two membrane is
low than, the required degree of purification cannot achieved. If pressure difference required
is too high than, the T.D.S in water gets increased. And due to increased T.D.S membranes of
the system gets choked. Possible time for choking needs to be predicted avoiding the
possibility of choking of the membrane during operation. Analytical analysis of R.O system
is required to be done and re-design of component of the plant including membranes.
Vibration is given to the membrane so that scaling will not produce and the plant is prevented
from chocking problem.

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Table of Contents
Topic Page No
Title Page I
Certificate II
Acknowledgements III
Abstract IV
List of Figures VIII
List of Symbols, Abbreviations and Nomenclature X
Chapter 1 Introduction 01
1.1 Reverse Osmosis Process 02
1.2 Principle of Reverse Osmosis 02
1.2.1 Why the RO is best process for water purification? 04
1.3 Component of RO plant 04
1.4 Filter 05
1.4.1 Types of filter 05
1.4.2 Filter materials 05
1.4.3 Water filter 06
1.4.4 Types of water filter 06
1.4.5 Filter problem 07
1.5 Pressure vessel 07
1.6 Membranes 07
1.6.1 Classification of Membranes 08
1.6.1.1 Asymmetric Membrane -Cellulose Acetate 08
(CA) Membrane
1.6.1.2 Thin Film Composite Membrane – 09
Polyamide (PA) Membrane
1.6.1.3 Comparison of Polyamide TFC Membranes 09
With Cellulose Acetate (CA) Membranes

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1.6.2 Types of Membrane According to Construction 10
1.6.2.1 Spiral-wound membrane 10
1.6.2.2 Tabular membrane 11
1.6.2.3 Plate & Frame membrane 11
1.6.2.4 Hollow fiber membrane 12
1.6.2.5 Advantages & Disadvantages of 13
Membrane
Chapter 2 Literature Review 14
2.1 Introduction 15
2.2 Summary of Papers Referred 15
2.2.1 Scale formation and control in high pressure 15
Membrane water treatment system
2.2.2 Reverse Osmosis Membrane Fouling 16
2.2.3 Evaluation of VSEP to Enhance Water Recovery 17
During Treatment of Brackish Water and RO
Concentrate
2.2.4 Engineering-Aspects-of-Reverse-Osmosis-Module 18
Chapter 3 Problem Definition 20
3.1 Problem 21
3.2 Technical Specification 21
3.3 Fouling 22
3.4 Scaling 23
Chapter 4 Optimization of Reverse Osmosis System 24
4.1 Introduction 25
4.2 Flow chart of RO System Optimization 25
4.3 Calculations 26
4.4 Optimization Technique 27
4.5 Results & Discussion 28
4.6 Conclusion of Optimization Procedure 31
Chapter 5 Cleaning in process (CIP) 32
5.1 Introduction 33
5.2 Timing for Cleaning 33
5.3 Cleaning Tank and Other Equipments 33

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5.4 Cleaning Procedure 34
5.5 Practically Generated Cleaning Procedure steps 37
5.6 Cleaning Chemicals 38
5.7 CIP Cost analysis 39
Chapter 6 Vibration Shear Enhanced Process 40
6.1 Problem of High Solid Wastewater 41
6.2 VSEP Principle 42
6.3 VSEP Operating Parameters 43
6.4 VSEP System Components 44
6.5 Advantages of VSEP System 46
6.6 Disadvantages of VSEP System 49
6.7 Modified VSEP (MVSEP) System 50
6.7.1 MVSEP RO System with Element 51
6.7.2 3D Visualization of the MVSEP RO System with 52
Element
6.7.3 Design of Modified VSEP 53
6.7.3.1 Design of Rotating motor shaft 53
6.7.3.2 Design of Connecting rod 54
6.7.3.3 Design of Big end Bearing 56
6.7.3.4 Design of Small end Bearing 57
6.7.3.5 Calculation for the Vibration of Membrane 57
Chapter 7 Conclusion 59
References 61
GTU Project Certificate 63
Project Registration 64

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List of Figures
No. Description Page No.
Fig 1.1 Principle of Reverse Osmosis 03
Fig 1.2 Substance remove from water by membrane filtration 04
Fig 1.3 Cartridge Filter 05
Fig 1.4 Filter materials 05
Fig 1.5 Water Filter 06
Fig 1.6 Pressure vessel assembly 07
Fig 1.7 Spiral wound membrane 10
Fig 1.8 Tabular membrane 11
Fig 1.9
Fig 1.10
Plate & Frame membrane
Hollow Fiber Membrane
11
12
Fig 3.1 Membrane Fouling 22
Fig 3.2 Membrane Scaling 23
Fig 4.1 Relationship between Pressure difference and Permeate
flow rate
29
Fig 4.2 Relationship between Permeate Concentration and
Permeate flow rate
30
Fig 4.3 Relationship between Permeate Concentration and
Pressure difference
30
Fig 5.1 Cleaning in Process Skid Diagram 34
Fig 6.1 Fouling in general RO System 41
Fig 6.2 Fouling in VSEP RO System 41
Fig 6.3 Inside look at the VSEP plate and frame assembly 42
Fig 6.4 Principle of VSEP 42
Fig 6.5 Skid Diagram of VSEP system 44
Fig 6.6 Principle of MVSEP system 50
Fig 6.7 Skid Diagram of MVSEP system with Elements 51
Fig 6.8 Skid Diagram of Multi channel MVSEP system 52

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Fig 6.9 3D Visualization of the MVSEP RO System 52
Fig 6.10 Connecting Rod 54
Fig 6.11
Fig 6.12
Cross section of Connecting Rod
Cross section of Membrane
54
57

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List of Symbols, Abbreviations and Nomenclature
Nomenclature:-
a permeability coefficient for water (m/h.bar)
asp specific surface area of the spacer (m-1)
A active area of membrane (m2)
b permeability coefficient for salt (m/h)
bπ osmotic coefficient (m3.bar/kg)
B total width of the membrane leaves in their unwound state (m)
Cb salt concentration in the high-pressure side (kg/m3)
Cp concentration of the permeate (kg/m3)
Cp,d desired permeate concentration (kg/m3)
Cpen penalty function constant
Cwall concentration at the membrane wall (kg/m3)
d channel height (m)
dh hydraulic diameter of channel (m)
dsp spacer thickness (m)
DAB mass diffusivity of salt (A) through water (B) (m2/h)
f (x) fitness function
F(x) objective function
Jw volumetric flux of water (m/h)
Js mass flux of salt (kg/m2.h)
Ks mass transfer coefficient of salt in feed side (m/h)
P pressure (bar)
Pen penalty function
Qf feed water volumetric flow rate (m3/h)
Qw permeate volumetric flow rate (m3/h)
Re Reynolds number
Sc Schmidt number
Sh Sherwood number
T temperature (°C)
v velocity of water in feed channel (m/h)

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Z objective function
J flux
JDI DI water flux through the clean membrane
Jsp,eff effective specific flux
kc mass transfer coefficient
TMP transmembrane pressure
μ DI viscosity of the dionized water
μ f viscosity of the feed solution
μ f,0 viscosity of feed at the beginning of filtration step
μ f,f viscosity of feed at the end of filtration step
T temperature
S salinity
r recovery
R resistance
RCP resistance due to concentration polarization
RCP,0 resistance of the CP layer at beginning of the filtration process
RCP,f resistance of the CP layer at end of the filtration process
RF resistance due to membrane fouling
Rm resistance of the membrane
RTOT total resistance
Rπ resistance due to osmotic pressure differential
Subscripts:-
b brine
f feed
o outlet
p permeate

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Greek Symbols:-
D difference
ε void fraction (bulk porosity or voidage)
μ dynamic viscosity of salt solution (Pa.s)
v kinematic viscosity of salt solution (m²/h)
π osmotic pressure (bar)
ρ density of seawater (kg/m3)
π osmotic pressure
Δπ osmotic pressure difference across the membrane
Abbreviation:-
GARO Genetic Algorithm Reverse Osmosis program
MSF Multi Stage Flash
pH Acidity Measure
RO Reverse Osmosis
VSEP Vibration Shear enhanced process
MVSEP Modify Vibration Shear enhanced process
AWTP Arsenic Water Technology Partnership
AWWA American Water Works Association
CIP clean-in-place
COD chemical oxygen demand
UF ultra filtration
UV ultraviolet
TDS total dissolved solids
SNL Sandia National Laboratories
SDI silt density index
SEM scanning electron microscope
DOC dissolved organic carbon
DOE Department of Energy
IC ion chromatography
ICP-MS inductively coupled plasma-mass spectrometry
MCL maximum contaminant level
MFI membrane fouling index

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MF microfiltration
DI deionised
CP concentration polarization
NOM natural organic matter
NF nano-filtration
NLR New Logic Research, Inc.
Units:-
cm centimetre
cm² square centimetre
d day
da Dalton
ft feet
g gram
gpd gallons per day
h hour
Hz hertz
In inch
in² square inch
kg kilogram
kPa kilopascal
kW kilowatt
L litre
M meter
m² square meter
m³ cubic meter
mg milligram
MGD million gallons per day
nm nanometre
ppm parts per million
μm micrometer
μS microsieme

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Chapter 1
Introduction

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1.1 Reverse Osmosis Process :-
―RO uses a high-pressure which is larger than osmosis pressure on the high
concentration side. So, the carrier is preferentially permeated, while the retentate contains
the rejected solute (contaminant). Thus, the membrane divides the water from the
contaminants. The main aim is to purify water and not dilute the contaminants.‖
1.2 Principle of RO:-
If two aques solutions containing differential salt contents are kept separated by a
semi permeable membrane, the system develops an inherent tendency for water
molecules(not the salt) to permit across the membrane layer to dilute the more
concentrated solution. This process is called Osmosis. The driving force per unit
membrane cross section, dependent on the concentration difference, is the Osmotic
pressure.

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Fig 1.1: Principle of Reverse Osmosis [1]
However, this natural process can be reversed if some external pressure higher than the
osmotic pressure is applied on the concentrated solution side whereupon water will pass
from the more concentrated solution, through the membrane boundary, to the less
concentrated solution. This is the working principle of the reverse osmosis.

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1.2.1 Why the RO is best process for water purification?
Pressure driven membrane processes are specially useful where a wide range of possible
contaminants have to be removed over the entire removal spectrum i.e. macro particles to
ionic species.
Fig 1.2: Substance remove from water by membrane filtration [11]
1.3 Components of RO plant :-
I. Filters
II. PH adjustment unit.
III. Pressure vessels.
IV. Membranes
V. High pressure Multistage pump
VI. Permeate Storage tank.
VII. Brine Storage tank.

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1.4 Filter:-
Filter is used for additional elimination of suspended solids and biochemical oxygen
demand. Filtration processes include sand filtration, and membrane filtration. To separate
substances which can cause problems to purification plant equipment. Heavy inorganic
solids such as sand, gravel, metal or glass are removed.
1.4.1 Types of filters:
1. Air filters
2. Fuel filters (DO & HFO)
3. Lube oil filters
4. Water filters
5. Hydraulic filters
6. Fine filters (magnetic)
Fig 1.3: Cartridge Filter [12]
1.4.2 Filter Material:
Fig 1.4: Filter Material [13]

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1.4.3 Water Filter:-
Fresh water filters need cartridges made of steel grid and with holes bored in it. It requests
finer net (0.1-0.5mm) over the holes. Sea water filters are also made of steel tin but with
rough net placed over the holes. Diameter of the holes is from 1 to 3mm.
Fig 1.5: Water filter [14]
1.4.4 Types of Water filter :-
I. Ceramic Filter.
II. Active carbon Filter.
III. Cartridge Filter.
IV. Ion-exchange Filter.
V. Ultraviolet Sterilization Filter.

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1.4.5 Filter Problems:-
I. Pressure drop
II. Reduced flow through filter - dirty oil is passing through it
III. To big flow (punctured filter)- dirty oil is passing through it
IV. Bad maintenance
V. Poor quality
VI. Bad oil or fuel quality
1.5 Pressure Vessel:-
Pressure vessel carries PVC, Stainless Steel, and Fiberglas (FRP) membrane
It carries membrane housings in a wide variety of sizes, end cap styles, pressure ratings,
and side or end entry designs.
Fig 1.6: Pressure vessel assembly [15]
1.6 Membrane:-
The maximum separation reached in membrane processes depends on the permeability of
the membrane for the feed solution components. A permeable membrane allows the
passage of all dissolved substances and the solvent. A semi permeable membrane is capable
of transporting different molecular species at different rates under identical conditions. The
ideal semi permeable membrane in membrane processes is permeable to the solvent only
but impermeable to all solutes.

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1.6.1 Classification of Membrane:-
MEMBRANE CLASSIFICATION
According To Basic Fundamentals
ORIGIN
MATERIAL
MORPHOLOGY
STRUCTURE
MEMBRANE
Synthetic Biological
SolidLiquid
Organic Inorganic
Non-porous Porous
1.6.1.1 Asymmetric Membrane -Cellulose Acetate (CA) Membrane:-
Historically, the asymmetric membrane is formed by casting a thin film acetone-based
solution of cellulose acetate (CA) polymer, which was developed by Loeb and Sourirajan
in 1962 and the first commercially viable RO membrane.
The resulting CA membrane has an asymmetric structure with a dense surface layer of
about 0.1 - 0.2 μm which is responsible for the salt rejection property. The rest of the
membrane, which is 100-200 μm thick and supports the thin surface layer mechanically, is
spongy and porous, and has high water permeability. Salt rejection and water flux of a CA
membrane can be controlled by variations in temperature and duration of the annealing
step.

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1.6.1.2 Thin Film Composite Membrane -Polyamide(PA) Membrane:-
Thin film composite (TFC) polyamide membranes are consisted of a porous support layer
and a thin film dense layer which is a cross linked membrane skin and is formed in situ on
the porous support layer, usually made of polysulfide.
The thin film dense layer is a cross-linked aromatic polyamide made from interfacial
polymerization reaction of a poly functional amine such as m-phenylenediamine with a
poly functional acid chloride such as tri-mesoyl chloride. This TFC manufacturing
procedure enables independent optimization of the distinct properties of the support and
salt rejecting skin. The TFC membrane is characterized by higher specific water flux and
higher salt rejection than cellulose acetate membranes.
1.6.1.3 Comparison of Polyamide TFC Membranes with Cellulose
Acetate(CA) Membranes:-
As mentioned above, the TFC membranes exhibit higher water flux and higher salt
rejection than CA membranes which had been used widely until the commercial
introduction of TFC membranes in 1981. TFC membranes are stable over a wider pH range
and operable at lower pressure than CA membranes. Detailed comparisons between the two
types of membranes are shown in the table below.

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1.6.2 Types of Membrane According to Construction:-
I. Spiral-wound membrane
II. Tabular membrane
III. Plate & Frame membrane
IV. Hollow fiber membrane
1.6.2.1 Spiral-wound membrane:-
. Fig 1.7: Spiral wound membrane [16]
Consist of two semi permeable membranes placed back to back and separated by a
woven fabric that functions as a permeate carrier, designed to prevent the membrane
from penetrating into it and to minimize permeate pressure drop. The three edges of the
membrane are sealed with adhesive, while the fourth one is attached to a perforated
central tube. When the package is rolled up, the membrane layers are separated by a
mesh that not only promotes turbulence, improving mass transfer but also reduces
concentration polarization.

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1.6.2.2 Tabular Membrane:-
Fig 1.8: Tabular membrane [17]
Each membrane is held in a porous tube. In practice, the feed stream is circulated
through tubes in series or parallel. Permeate solution passes through the membrane,
through the tube and drops off into a receptacle for further permeate removal.
1.6.2.3 Plate & Frame Membrane:
Fig 1.9: Plate & Frame membrane [18]
Consists of circular membranes sealed to both sides of a rigid plate (constructed of plastic,
porous fiberglass or reinforced porous paper), which acts as mechanical support and as
permeate carrier. These units are placed in a pressurized vessel for use. Each plate in the
vessel is at low pressure, so that permeate passes through the membrane and is collected in
the porous media.

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1.6.2.4 Hollow Fiber Membrane:-
Fig 1.10: Hollow fiber membrane [19]
Consist of a shell which houses a very large number of hollow membrane fibers. The
membrane fibers are grouped in a bundle, evenly spaced about a central feed distributor
tube. One end of the fiber is sealed and the other is open to the atmosphere. This bundle is
inserted into a pressure container for use. During operation, pressurized feed water is
introduced through the distributor tube which flows around the outer side of the fibers
toward the shell perimeter. The permeate penetrates through the fiber wall into the bare
side and is removed at the open ends of the fiber

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1.6.2.5 Advantages & Disadvantages of Membrane:-

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Chapter 2
Literature Review

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2.1 Introduction :-
A literature review for the present work was carried out. Various research
papers and Web articles were studied relevant to the topic of work.
2.2 Summary Of Papers Referred :-
2.2.1 “Scale formation and control in high pressure membrane water
treatment systems”
Author Name:
Alice Antony, Jor How Low, Stephen Gray, Amy E. Childress, Pierre Le-Clech, Greg Leslie
UNESCO Centre for Membrane Science and Technology, The University of New South
Wales, Sydney 2052, Australia
Compared to the increasing research activities in various aspects of membrane technology and
applications, studies related to the use of chemical additives in membrane systems are limited.
More specifically, there is a huge research requirement for the use of antiscalants that has not been
addressed so far, not necessarily related to their performance alone. Some of the knowledge gaps
identified from the literature review include:
Scale formation and subsequent performance decline still remain a challenge for RO systems as
evidenced from membrane autopsy reports, in spite of the availability of a suite of scale prediction
tools and a range of scale mitigation measures practiced in the water treatment industry.
Studies on antiscalant suitability and efficiency are generally performed with commercially
available antiscalants; given that antiscalant formulations are proprietary in nature, it makes it
hard to assess and understand the antiscaling efficiency at the molecular level for modelling and
prediction of outcomes. A greater transparency in terms of the constituents will help molecular
level understanding of different categories of chemical additives to various scale types.

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Research on scale formation and control, especially, assessing antiscalant efficiency has usually
been performed with individual and model solutions. Although this helps in assessing the
efficiency for individual components, it fails to mimic complex water chemistries, where there is
possibility of co-precipitation of more than one component of unknown proportions. It is apparent
the scale usually noticed in reverse osmosis systems operating on natural waters differs from what
would be expected in controlled conditions. Studies aimed with mixed salt solution, real feed
types and incorporating molar ratio approach would help solving this.
Similarly some of the scale assessment techniques were targeted for specific antiscalants or scale
limiting approaches for particular waters. Rather, these techniques should be made industrious
after method development, by taking them to more complex water.
Potential to form various scales are generally estimated from the different scale prediction
techniques and appropriate antiscalant is selected for the given feed type, since antiscalants are
mostly selective to mitigate a specific scale type. Therefore, in achieving scale
suppression/inhibition of a mixture of scales, generally a formulation consisting of a mixture of
antiscalants is recommended by the antiscalant manufacturers. Taking into account the selectivity
of antiscalant action, the overall inhibition efficiency could be a summation of individual
efficiencies, a synergistic or an antagonistic effect.
2.2.2 “Reverse Osmosis Membrane Fouling”
Author Name:
David H. Paul, Inc., P.O. Box 2590, Farmington, NM 87499, USA
Abdul Rahman M. Abanmy, Saline Water Conversion Corporation,
Research and Development Centre, P.O.Box 8328, Al-Jubail, 31951
The phenomena of colloidal and bacteriological fouling of RO spiral wound brackish
water membranes is reviewed. Generalizations from the literature about the mechanism of action
of fouling are described. The monitoring methods used to measure colloidal and bio fouling
potential of feed water is reviewed. The action of disinfectants and chemical cleaning agents on an
established fouling layer is discussed. The need for extensive addition research is apparent.

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Fouling occurs to some degree in all RO systems. There are several types of foulants,
including inorganic foulants (colloids and precipitates) and organic foulants (dissolved organics
and microorganisms). The mechanisms of action of the individual fouling processes have been
minimally researched. The effect of combinations of fouling processes is unclear.
Accurately monitoring the fouling potential of RO feed water has many limitations at this
time. Most existing measurements of colloidal and bacterial fouling potential are fairly good
qualitative indicators but inaccurate quantitative indicators. Even with their limitations, they
provide valuable information and must be used. Understanding their limitations, however, helps
us to interpret the often confusing and conflicting results that we see.
Removal of an established fouling layer is attempted by exposing it to disinfectants and/or
chemical cleaning agents. The effectiveness of removal varies from minimal to nearly l00%,
depending upon the nature of the fouling layer, on the cleaning / sanitizing formulation used, and
on the cleaning procedure. The fouling layer changes with time. Cleaning effectiveness of a
single formulation may change accordingly.
2.2.3 “Evaluation of VSEP to Enhance Water Recovery During Treatment of
Brackish Water and RO Concentrate.”
Author Name:
Mark M. Benjamin and Wei Shi Dept. of Civil and Environmental Engineering University
of Washington Seattle, WA.
Pierre Kwan and Yujung Chang, HDR Engineering, Inc. Bellevue, WA.
This research project investigated the use of Vibratory Shear-Enhanced Processing (VSEP)
filtration to produce potable water from either brackish water or the brine generated in reverse
osmosis desalination units. The VSEP process is characterized by the use of disk-shaped
membranes that are rotated rapidly (~55 Hz) in the plane of the disk, first for a short distance in
one direction and then in the other.

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The systems can be used with membranes having any pore size, but only reverse osmosis (RO)
membranes were used in the current research. Both synthetic solutions and real solutions from
full-scale operating systems were investigated as feeds to the VSEP unit.
In addition to the differences in feed composition, parameters that were investigated included the
presence or absence of membrane motion (referred to as vibration by the manufacturers of VSEP
systems), the amplitude of the vibration, the pH and dissolved silica content of the feed, the trans
membrane pressure (TMP), the presence or absence of a proprietary antiscalant in the feed, the
presence or absence of natural organic matter (NOM) in the feed, and the presence or absence of a
relatively large concentration of suspended inorganic solids (either CaCO3 or SiO2) in the feed.
Parameters that were measured as indicators of process performance and/or membrane fouling
included the volumetric flux through the membrane, the effective specific flux, the rejection
efficiency for conductivity and various specific solutes, the identity of solids that were generated
in the concentrate or accumulated on the membrane during the treatment process, and the
morphology of the deposited solids.
2.2.4 “Engineering-Aspects-of-Reverse-Osmosis-Module.”
Author Name:
Jon Johnson, Markus Busch.
This paper focuses on the transition process in RO module configuration, and how this
transformation helped to achieve the above described performance improvements. It can be seen
how the development of thin film composite membrane and spiral wound element configuration
helped achieving larger rejection and higher productivity which resulted in better water quality
significantly lower energy consumption, and improved system operation (lower fouling, higher
recovery).
The review of various spiral wound component and engineering aspects shows the
following:
Feed spacers play a critical role in trading off membrane support and feed mixing, hence in
providing low energy, low fouling and high membrane area density in the vessel. However,

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despite considerable R&D investment, have undergone little change since the early production
principles.
The product water tube has been hydraulically been optimized, but more improvements (sensoring
/ probing, grips supporting loading / unloading) are possible and are being explored.
The connection system between RO elements has been optimized and some disadvantages of
sliding couplers (abrasion, stress) have been eliminated by interlocking end caps.
Multi-year effort to develop 16-inches module have been completed, and these provide potential
to improve plant design and economics, however issues with regards to system engineering and
element loading still need to be addressed.

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Chapter 3
Problem Definition

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3.1 Problem:-
• Following Problem Normally Occurred in Industrial R.O Plant.
I. Pressure drop increase.
II. T.D.S removing capacity is decreases.
III. Higher Energy Consumption.
IV. Scaling and Fouling occur on membrane surface.
• Plugging produced within 200 hrs.
3.2 Technical Specification:-
 Plant Data :
 Number of Unit 5
 Capacity of Unit (m3/day) 100
 Unit :
 Product Water Flow (m3/h) (m3/day) 47 (1128)
 Reject Water Flow (m3/h) (m3/day) 103 (2472)
 Total Water Feed Flow (m3/h) (m3/day) 150 (5640)
 Operating Condition :
 Temperature (°C) 28
 Bulk feed water Concentration (ppm) C 44000
 Permeate Water Concentration (ppm) 350
 Membrane Pressure Difference, ∆P (bar) 65.845
 Membranes :
 Number of Vessels 15
 Number of Membranes in Vessel 5
 Total Number of Membranes 75
 Diameter of Membrane (inch) (m) 8 (0.2032)

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 Length of Membrane (inch) (m) 40 (1.016)
 Membrane Surface Area (ft2) (m2) 300 (27.87)
 Width of Membrane B (m) 27.432
 Spacer Thickness dsp (m) 0.00054
 Porosity ε 0.91
 Hydraulic Diameter dh (m) 0.0007226
 Specific Surface of Spacer asp(1/m) 14814.815
3.3 Fouling:-
Fig 3.1: Membrane Fouling [4]
• Biological or colloidal fouling
• Sulphate salts (CaSO4)
• Silica fouling can be more difficult to predicted & control than other types of fouling.
• Soluble silica is concentrated to insoluble levels in RO process
• Effluent organics can adsorb onto membrane element surface, causing pore clogging &
even a change in membrane surface charge.

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3.4 Scaling:-
Fig 3.2: Membrane Scaling [5]
• Scaling is the precipitation and deposition within the RO system of sparingly soluble salts
such as calcium carbonate (CaCO3), calcium sulphate (CaSO4) and barium sulphate
(BaSO4).
• Scaling causes the nominal flux to decrease. The consequences are, as has been noted
before, a higher energy use, an increase of the cleaning frequency and a shorter life span of
the membranes. This will cause the membrane water treatment process to become much
more expensive.

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Chapter 4
Optimization of
Reverse Osmosis
System

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4.1 Introduction:-
The optimization of RO systems is achieved by the genetic algorithms (GA)
technique. The objective function is taken as the maximization of permeate volumetric flow rate.
The optimization problem is to find the best pressure difference across the membrane which
maximizes permeate volumetric flow rate and fulfil the permeate concentration constraint. The
used constraint is that permeate concentration to be less than a desired value.
4.2 Flow chart of RO System Optimization:-

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4.3 Calculations:-
 π is the osmotic pressure (in bars) obtained from the data given by Sourirajan (1970) for
the NaCl–H2O solution at 25°C (concentration range: 0 - 49.95 kg/m3) and is correlated
as,
 For feed water, DAB, μ and ρ (Sekino, 1994; Taniguchi and Kimura, 2000; Taniguchi et
al., 2001) can be estimated from the following equations:
Where,
So, from eq (4),
 For a flow Q through the spacer filled channel, the velocity is defined by,

UCET Page 27
(Where, d is approximated by the spacer thickness dsp. The width B should be taken as
the total length of the membrane leaves in their unwound state.)
 The hydraulic diameter, dh , is given by Schock and Miquel, 1987; Van Gauwbergen
and Baeyens, 2000 as,
(where is the void fraction (bulk porosity or voidage), d is the channel height, and asp is
the specific surface area of the spacer, i.e. the ratio of its surface area to its volume. It is
given by asp = 8 / dsp , where dsp is the spacer thickness.)
 The osmotic coefficient bπ can be estimated using:
 Kinematic Viscosity V, is define as,
 The mass transfer coefficient can be expressed in an empirical Sherwood relationship
taking into account the flow conditions (expressed in the Reynolds number, Re), the
nature of the feed solution (expressed by the Schmidt number, Sc) and the geometry of
the membrane system. For a spiral-type RO element, which is in the case study, the
Sherwood relationship is given by Taniguchi et al. (2001) as,
Where, the Sherwood, Reynolds and Schmidt numbers are defined as,
By putting the value of eq (13) and (14) in eq (11) we get, Sh = 531 (15)

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 The permeability coefficients of water and salt a and b, The values of a and b are 1.1212
x 10¯⁶ m/bar.s and 2.264 x 10¯⁷ m/s respectively. These values depend on the
membrane and do not depend on the values of ΔP. Therefore, these values are used in
the optimization process.
Now, for finding the value of ks (mass transfer coefficient of salt in feed side) (m/h)
equating the equation (11) & (12), we get Ks = 0.95635 m/h (16)
 The solvent (water) flux Jw is defined as the volume of water passing through a unit area
of the membrane. The brackish water flux is 8.45 m/h.
 Now, by using the following equation we get the value of Cp concentration of the
permeate (kg/m3)
4.4 Optimization Technique:-
 For a given RO system layout (number of channels, membrane area, … etc.), the single
objective function Z to be maximized is:
(18)
 Optimization of an existing RO system is a constrained optimization problem. The
constraint used in such system is given as:
(here, Cp is 348.23 ppm and Cpdi is 350 ppm. So, above condition is approximate satisfied,
If it is not satisfied, for this external penalty function is introduce.)
{In optimization techniques, external penalty functions have been used to convert a
constrained problem into an unconstrained problem. Therefore, for the RO system
optimization, the objective function Z is given as:

UCET Page 29
where, Cpen is the penalty function constant and is chosen as big as 100 ppm.
Therefore, the objective function can be calculated from:
The penalty function is applied when the permeate concentration is not less than the
desired permeate concentration.}
4.5 Results & Discussion:-
Fig 4.1: Relationship between Pressure difference and Permeate flow rate
 The relationship between pressure difference and permeate flow rate is approximately
linear. Therefore, the maximum value of Qw corresponds to the upper bound of ΔP (100
bar in this case).
 The modeling of the RO plant is seen to be in a good agreement with the experimental
results obtained in the case study with a considerable difference at lower permeate flow
rates.

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Fig 4.2: Relationship between Permeate Concentration and Permeate flow rate
• The constraint that Cp to be lower than the desired value Cp,d is fulfilled. Under these
conditions, Cp decreases gradually below Cp,d with the increase of Qw till it reaches the
value of 189.3 ppm at Qw = 485.496 m3/h.
• The deviation increases with decreasing the permeate flow rate as shown in the figure
4.2.
Fig 4.3: Relationship between Permeate Concentration and Pressure difference
 From the above figures, it can be seen that the operating point of the RO plant is exactly
on the optimal results obtained from program.

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4.6 Conclusion of Optimization Procedure:-
1. The relationship between the operating pressure difference across the RO membrane and
permeate volumetric flow rate is approximately linear.
2. The permeate concentration decreases with the increase in volumetric flow rate and the
membrane pressure difference.
3. The theoretical results from the optimization program are seen to be in a good agreement
with that experimentally obtained specially at higher flow rates.

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Chapter 5
Cleaning in
Process(C.I.P)

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5.1 Introduction:-
Fouling of RO membrane is more or less a normal phenomenon of most RO systems since
the pre-treatment of the feed water prior to the RO membrane is basically designed to reduce
fouling substances as much as possible and technically could not remove all of them. Fortunately,
with correct cleaning frequency, most foulants can be removed from the membrane. The cleaning
frequency could be minimized as long as the pre-treatment is well maintained without upset
conditions such as an uncontrolled change in feed water composition and uncontrolled biological
contamination. Sometimes mistakes in the system operation such as too high recovery and failure
of chemical dosing systems could end up with fouling the membrane.
The fouling of membrane surfaces results in lower permeate flow rate and/or lower salt
rejection. Increased pressure drop between the feed and concentrate side can also occur from the
fouling.
5.2 Timing for Cleaning:-
Elements should be cleaned immediately when one of the following symptoms is detected:
 Loss of 10 to 15% in normalized permeate flow rate
 Decrease of 0.5% in salt rejection.
The differential pressure (feed pressure - concentrate pressure) ΔP increases by 15 % from
the reference conditions (initial performance established during the first 24 to 48 hours of
operation).
5.3 Cleaning Tank and Other Equipments:-
The mixing tank for cleaning agents should be made of polypropylene or FRP which is
resistant to pH in the range of 1 to 12. The cleaning agents work better at an elevated
temperature. (e.g. 35 – 40 ℃). The cleaning temperature should not be below 15 ℃ at which the
cleaning rate is very slow. Cooling may also be required to avoid overheating. So the heating
and cooling equipments may be necessary to control the temperature of the cleaning solution.

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5.4 Cleaning Procedure:-
1. Fill the cleaning tank with RO permeate water. The volume of cleaning solution should
be sufficient to fill all the pressure vessels and pipe lines. Add the calculated amount of
the cleaning chemicals to the tank. Use a mixer or re-circulate the solution with the
transfer pump to ensure that all chemicals are dissolved and well-mixed before
circulating the solution to the elements.
2. Drain most of the water from the RO system to prevent the dilution of the cleaning
solution by water within the RO system.
Fig 5.1: Skid diagram of cleaning procedure

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3. Heat the solution to the temperature recommended by the manufacturer to improve
cleaning effectiveness.
4. Pump the preheated cleaning solution to the vessel at conditions of low flow rate and
low pressure to displace the process water remaining in the vessel. Dump the displaced
water until the presence of the cleaning solution is evident in the RO concentrate system
or in the return pipe, indicated by the pH and temperature of the cleaning solution.
Adjust flow rate and pressure according to the Table 1. Open the RO concentrate
throttling valve completely to minimize operating pressure during cleaning. Use only
enough pressure to re-circulate the cleaning solution without permeate coming out.
Element
Diameter
(m)
Maximum Feed Flow Rate
(gpm) (m3/h)
2.5 5 1.1
4 10 2.3
8 40 9
5. Recycle the concentrate to the cleaning solution tank until the desired temperature is
maintained throughout the solution. Observe any increase in the turbidity to judge
efficiency of the cleaning solution, especially in the case of an alkaline cleaning solution
or a detergent solution. If the cleaning solution becomes turbid or colored, drain the
solution and restart with a freshly prepared cleaning solution. Check the pH during acid
cleaning. The acid is consumed when it dissolves inorganic precipitates. If the pH
increases more than 0.5 pH unit, add more acid.
6. Turn the pump off and allow the elements to soak. Sometimes a soak period of about 1
hour is sufficient. For difficult fouling an extended soak period is beneficial; soak the
elements for 10-15 hours. To maintain a high temperature during an extended soak
period, use a slow recirculation rate.
7. Circulate the cleaning solution at the rates shown in Table 1 for 30-60 minutes. The high
flow rate flushes out the foulants loosened from the membrane surfaces by the cleaning.
If the elements are heavily fouled, a flow rate which is 50 % higher than shown in Table

UCET Page 36
1 may aid cleaning. At higher flow rates excessive pressure drop may be a problem. The
maximum recommended drops are 1.4 bar (20 psig) per element or 4.1 bar (60 psig) per
multi-element vessel. The direction of flow during cleaning must be the same as during
normal operation to avoid telescoping of the elements.
8. Drain the used cleaning solution out of the system. Analyze a sample of the used
solution to determine the types and the amount of substances (fouling materials)
removed from the membrane elements. The results could tell the degree of cleaning and
the causes of fouling.
9. RO permeate or good quality water (filtered, SDI < 3), free of bacteria and chlorine,
conductivity <10,000 μS/cm is used for flushing out the residual cleaning solution. The
minimum flush out temperature is 20 ℃ to prevent precipitation.
10. The RO plant is started up again resuming normal operating conditions. However, the
permeate must be drained until conductivity and pH returns to normal. And also the
permeate side draining is necessary when another cleaning cycle with another cleaning
chemical is to follow. During the rinse out step, the operating parameters should be
noted to judge the cleaning efficiency and to decide if another cleaning is required. If the
system has to be shut-down after cleaning for longer than 24hours, the elements should
be stored in a preservation solution such as 1 % sodium bisulphite and 0.5 %
formaldehyde. For multi-array systems, cleaning should be carried out separately for
each array. This can be accomplished either by using one cleaning pump and operating
one array at a time, or using separate cleaning pump for each array.

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5.5 Practically Generated Cleaning Procedure steps:-

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5.6 Cleaning Chemicals:-
Choosing right cleaning chemicals is important since harsh and frequent cleaning will
shorten the membrane life, and sometimes a wrong choice of cleaning chemicals can
worsen the fouling situation. The cleaning will be more effective if it is tailored to the
specific fouling problem. Therefore, the type of foulants should be determined prior to
cleaning, there are helpful ways to determine the type of foulants as shown below:
 Analyze the plant performance data.
 Analyze the feed water to find potential fouling substances.
 Check the results of previous cleanings which may indicate specific fouling substances.
 Analyze the foulants collected with a membrane filter used for SDI measurement.
 Analyze the deposits on the cartridge filter.
Foulant Cleaning Chemical Comments
Inorganic salts
(CaCO3,CaSO4,BaSO4)
0.2% Hydrochloric Acid.
0.5% Phosphoric Acid.
2.0% Citric Acid.
Best
O.K
O.K
Metal Oxides 0.5% Phosphoric Acid
1.0% Sodium
Hydrosulphite.
Good
Good
Inorganic Colloids 0.1% Sodium Hydroxide
(NaOH), 30℃
0.025 Sodium
Dodecylsulfate/0.1%
NaOH, 30℃
Good
Good
Bio films 0.1% Sodium Hydroxide,
30℃.
1.0% Sodium Ethylene
Diamine Tetra Acetic
Acid (Na4 EDTA) and
0.1% NaOH, 30℃
Best
Best when
biofilm
contains
inorganic
scaling

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5.7 CIP Cost analysis:-
TOTAL COST- 1881 Rs
 ONE MEMBRANE REPLACEMENT COST - 1440 RS
 NO OF MEMBRANE USED IN 1 CHANNEL - 5
 TOTAL NUMBER OF CHANNELS - 15
 TOTAL MEMBRANE USE IN RO PLANT - 75
 TOTAL MEMBRANE REPLACEMENT COST - 108000
Positive Outcome of Chemical Process- 7200(5x1440) - 1881 = 5319 Rs
Organics 0.025%Sodium
Dodecylsulfate/0.1%
NaOH, 30℃.
0.1% Sodium
Triphosphate/1% Na4
EDTA
Good
Good
Silica 0.1% Sodium Hydroxide,
30℃.
1.0% Sodium Ethylene
Diamine Tetra-acetic
Acid (Na4 EDTA) and
0.1% NaOH, 30℃
O.K
O.K
MATERIAL QUANTITY PRIZE
NET
PRIZE
S.L.S 2.5 kg 65 162
CAUSTIC
SODA
1.5 kg 26 39
S.M.B.S 20 kg 12 240
CITRIC
ACID
60 kg 24 1440

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Chapter 6
Vibration Shear
Enhanced Process

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6.1 Problem of High Solid Wastewater:-
High solid wastewater has always provided challenge to membrane filtration due to rapid fouling
tendency. Membrane module configuration is considered along with cross flow velocity as a
primary way to control this problem. This in some instances resulted in very high circulation flow
rate especially in capillary and tubular membrane configurations. Introducing air (either during
service or during backwash does provide help in some wastewater applications). But introducing
vibration is a relatively new approach in case of wastewater with high solid content. As shown in
figure 1, conventional cross flow results in formation of a boundary/gel layer on the membrane
surface resulting in flux declination that in some cases irrecoverable and shortens the membrane
life.
Figure 6.1: Fouling in general RO System [6]
Figure 6.2: Fouling in general RO System [6]

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6.2 VSEP Principle:-
Introducing vibration at the membrane surface exactly where it is needed, reduces the tendency to
form any layer that results consistent flux. In combination with the appropriate type of membrane
and material selection VSEP can provide an effective solution. In a typical VSEP system,
membranes are arranged in a plate and frame configuration (figure 3). Different types of
membrane (Microfiltration, Ultrafiltration, Nanofiltration, Reverse Osmosis) can be used in a
VSEP module to achieve the required product quality. The VSEP system requires a careful pilot
test protocol to obtain a right membrane material in combination with vibration to provide a very
stable flux.
Figure 6.3: Principle of VSEP [6]
Figure 6.4: Inside look at the VSEP plate and frame assembly [6]

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At the core of VSEP's highly efficient operation is a patented resonating drive system (figure
4).This system achieves high energy efficiency by applying shear into a thin zone near the filter
surface. This precise application of shear results in efficient energy conversion and very low
power consumption.
6.3 VSEP Operating Parameters:-
Membrane selection is the single most important parameter that affects the quality of the
separation. Other important parameters that affect system performance are pressure,
temperature, vibration amplitude, and residence time. All of these elements are optimized
during testing and entered into the programmable logic controller (PLC) that controls the
system. The operating pressure is created by the feed pump. VSEP machines can routinely
operate at pressures as high as 68 bar. While higher pressures often produce increased permeate
flow rates, they also use more energy. Therefore, an operating pressure is used that optimizes
the balance between flow rates and energy consumption. In most cases, the filtration rate can be
further improved by increasing the operating temperature. The temperature limit on a standard
VSEP system depends on the membrane selected and can be as high as 90°C. This is
significantly higher than competitive membrane technology. Even higher temperature
constructions are available to treat streams up to 130°C. The vibration amplitude and
corresponding shear rate can also be varied which directly affects filtration rates. Shearing is
produced by the torsion oscillation of the filter stack. Typically the stack oscillates with
amplitude of 1.9 to 3.2 cm peak-to-peak displacement at the rim of the stack. Feed residence
time is set by the frequency of the opening and closing of the exit valve (valve one). The solids
level in the feed increases as the feed material remains in the machine. Occasionally, a cleaner
is added to the membrane stack and continued oscillation helps clean the membrane in minutes.
This process can be automated and only consumes approximately 190 litres of cleaning
solution thus reducing cleaner disposal problems inherent with other membrane systems.

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6.4 VSEP System Components:-
Figure 6.5: Skid Diagram of VSEP system
The VSEP filtration system consists of 6 major components: the VSEP (Frame, Drive System, and
Plumbing), Filter Pack, Interconnecting Piping, Feed Pump Skid, and Metering Pump Skid (with
Cleaning Chemical Totes). For complete specifications, please visit the corresponding product
page.
Frame
A 2" tubular steel construction is used with an epoxy powder coat to assure resistance to
chemicals and weather. The Frame provides structural support and vibration dampening for the
Drive System, Plumbing, and Filter Pack.
Drive system
This patented system includes a 10-20 horse power motor which drives an eccentric weight and
seismic mass, which in turn translates the energy through the torsion spring into the Filter Pack.
Plumbing
Teflon reinforced flex hoses and stainless steel are used to assure maximum compatibility with
most solvents, caustics and acids, and vibration dampening for Interconnecting Piping.

UCET Page 45
Filter Packs
VSEP filter packs employ a filament-wound outer housing, membrane trays, stainless steel end
plates, polypropylene or Kynar permeate carriers and epoxy resins. The membrane trays consist of
a stainless steel disc, drainage cloth and the membrane. The trays are separated by metal spacers
and rubber gaskets, which provide the spacing for the feed to flow over the trays. The assembly is
compressed so that the gaskets form a seal to prevent leaking. acrylic; nylon; polyacrylonitrial
(PAN); polypropylene; polysulfide; polycarbonate; PVDF (Kynar); stainless steel; Teflon; thin-
film composites; Tyvek and others. Most of these membranes have a wide range of pore sizes to
choose from ensuring the optimum separation for any application. The standard modular size of a
VSEP System is 100 to 1,500 square feet composed of discs with a 19 inch (48 cm) active
diameter. Each disc element is manufactured and quality-assured by New Logic.
Interconnecting Piping
A network of piping transfers feed or cleaning solution to the VSEP Filter Pack from the Feed
Pump Skid, and then back as Permeate (clean) and Concentrate (reject) streams. This piping also
includes flexible hoses that help dampen VSEP vibration from being transferred back to the Feed
Pump Skid.
Feed Pump
The feed pumps are used to pump cleaning solution from the cleaning tank to the VSEP Filter
Pack. Valves are used to change destinations between cleaning and feed. Instrumentation is used
for system status and for alarms that protect the filter pack. The electrical circuitry contains two
enclosures; one for electrical components and one for solenoid air valves. There is also motor
speed controllers, which are solid state control device used to run the vibration drive motor, and
feed pump motors. The speed of the motor controls the vibration amplitude, and feed pressure.
The control circuitry cabinet contains the PLC programmable logic controller, HMI touch display,
and the AC and DC control circuitry.
Metering Pump
This allows for automatic transfer of cleaning chemicals to the Feed Pump Skid cleaning tank.
The run time of these pumps is controlled by timers in the programmable logic controller.

UCET Page 46
Control System
Operation of the VSEP system is automated by the PLC. The bulk flow passes through a coarse
bag filter prior to entering the VSEP system to ensure large particles (bigger than beach sand) are
removed.
The feed water then flows to the VSEP module. The water is fed through the top of the filter pack,
the permeate (clean water) exits the top of the filter pack and the concentrate (rejected material)
exits the system through a pipe at the bottom of the filter pack. A valve on the concentrate exit is
throttled to maintain the proper recovery level (amount of clean water recovered as a percentage
of the total).
Once or more times per week, the PLC takes the VSEP module offline for a cleaning. By
controlling the air-actuated valves, the PLC rinses the filter packs with warm water, then and then
meters approximately seven gallons of concentrated chemical cleaning solution into a 300 gallon
clean-in-place (CIP) tank mounted on the VSEP CIP skid. The dilute cleaning solution is fed
through the filter pack, and the first 10% of the flow is diverted to drain. This 10% will contain
roughly 90% of the potential foulants within the filter pack. The remaining 90% of the solution is
re-circulated for 30 minutes. The PLC then initiates a warm water rinse, after which the second
cleaner is metered into the tank and the cleaning process is repeated. After a final warm water
rinse, the module goes back online.
The VSEP system does not require a dedicated operator. The PLC controls all important aspects
of the VSEP operation and will shut down upon any alarm-inducing conditions. The VSEP PLC
can monitor tanks and equipment before and after the VSEP system to prevent overflows, etc. The
operator is required to make routine checks to the system at regular intervals. See the Preventative
Maintenance section of the Appendix for further information.
6.5 Advantages of VSEP System:-
Eight reasons why VSEP outperforms conventional separation systems:
1. High Filtration Rates
2. Fouling Resistance
3. High Solids
4. High Efficiency
5. Engineered Dependability
6. Compact Design
7. Low Cost

UCET Page 47
1. High Filtration Rates
VSEP filtration rates average ten times higher than competing separation technologies.
Membrane-based separations have always had limitations as well as advantages. Limitations such
as high operating costs and low filtration rates made them inefficient to work with. Yet the
advantages such as precise separation, crystal clear filtrate, controlled size exclusion (from
microns to molecular dimensions) and excellent materials compatibility was compelling. With
these advantages in mind, New Logic set out to make the innovations necessary for membrane
separations to enter the mainstream. Now, VSEP is the only filtration system offering high
sustainable filtration rates (despite high suspended solids) in a single pass.
2. Fouling Resistance
VSEP's patented vibratory shear process keeps the filter surface clean.
There are major features and benefits built right into VSEP that were never before available in
conventional filter systems. And it's the vibratory shearing action that makes it all possible. The
shear produces high filtration rates in separations ranging from low molecular weights through 30
microns, making VSEP the only system of its kind and the first real technological breakthrough in
separations to come along in many years.
Remarkable results are achieved through VSEP's vibratory shear enhanced processing. The
application of intense shear waves at the membrane surface prevents the age-old problem of
membrane fouling. The shearing action actually sweeps away foulants from the membrane
surfaces, making rapid filtration possible, even with high solids. There is no product loss (as in a
centrifuge or filter press) and the system requires no flocculent additions (as with rotary drum
filters and clarifiers) and no high energy costs (as with evaporation and biological equipment).
3. High Solids
Achieving high solids in a single pass simplifies processing.
The feed slurry in a VSEP system can be extremely viscous (up to 70% solids) and still be
successfully processed. The way it works is simple. As the membrane leaf elements vibrate
vigorously, the shear waves produced cause solids and foulants to be repelled and liquid to flow
through the membrane pores unhindered. The shear rate at the membrane surface is approximately
150,000 inverse seconds, literally ten times greater than the rates obtainable in cross flow
filtration systems.

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4. High Efficiency
VSEP's energy-to-shear conversion rate is 99%
At the core of VSEP's highly efficient operation is a patented resonating drive system. This
system achieves high energy efficiency by applying shear into a thin zone near the filter surface.
This precise application of shear results in efficient energy conversion and very low power
consumption. A typical VSEP system consumes less than 20 hp.
VSEP allows nearly 99% of the total energy utilized to be converted to shear at the membrane
surface. Compare this to a typical cross flow filtration system where as little as 10% of the energy
is converted to shear on the membranes.
5. Engineered Dependability
Only two moving parts and a self-repairing membrane system eliminate costly downtime.
VSEP is a simple, compact, closed system. Under normal operating conditions, VSEP will require
the same level of attention as a pump. It will perform the instant power is applied, and the
resulting separation is a pure physical occurrence.
VSEP only has two moving parts: the torsion spring — which is tested to assure infinite life; and
the bearings — which are lubricated automatically. Additionally, the patented redundant
membrane system, which automatically self-repairs in case of membrane element failure,
guarantees uninterrupted performance.
6. Compact Design
Only 16 square feet of floor space replaces systems 10 to 100 times larger.
A VSEP system occupying only 20 square feet of floor space can support up to 1500 square feet
of membrane area and do the work of a system 10 to 100 times larger. The system is also modular
for easy expansion. Installation of a system is no more complicated than the installation of a
pump.
7. Low Cost
Reduced energy, maintenance and processing time add up to low cost.
An extremely attractive cost-to-performance ratio combined with VSEP's exclusive features add
up to one of the lowest-cost systems of its kind.

UCET Page 49
• High flux rates mean more throughput capacity per dollar of capital invested.
• Fouling resistance means less membrane replacement and less cleaning and maintenance due to
fouling.
• High solids, achieved in a single pass, simplifies processing.
• High efficiency lowers operating expenses.
• Engineered dependability eliminates costly down time.
• Compact design means savings on installation, space requirements and plant design.
• Convenient testing lowers cost by limiting technical risk.
6.6 Disadvantages of VSEP System:-
 Design constraints in utilizing the resonant vibratory response at 49~56 Hz.
- Complicate vibration excitation mechanism
- Requires a vertical high rod as a torsional spring
 Requires a VSEP system/filter module.

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6.7 Modified VSEP (MVSEP) System:-
Figure 6.6: Principle of MVSEP system
 Direct excitation mechanism of disk tube filter module using a crank arm and connecting
rods.
• Vibration frequency: Controlled by the motor RPM.
• Vibration amplitude: Determined by the distance from motor shaft centre to crank pin.

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6.7.1 MVSEP RO System with Element:-
Figure 6.7: Skid Diagram of MVSEP system with Elements

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Figure 6.8: Skid Diagram of Multi channel MVSEP system
6.7.2 3D Visualization of the MVSEP RO System with Element:-
Figure 6.9: 3D Visualization of the MVSEP RO System
• Motor
• Crank
• Crank Shaft
• Connecting Road
• Bearings

UCET Page 53
6.7.3 Design of Modified VSEP:-
 Design of Rotating Shaft of Motor
 Design of Connecting rod
 Design of Big end Bearing
 Design of Small end Bearing
 Calculation for the Vibration of Membrane
6.7.3.1 Design of Rotating Shaft of Motor:-
Motor Specification:
Power = 50 hp.
Speed = 500 rpm.
Calculation of Diameter of Rotating Shaft:
P = 50hp = 50 x 745 = 37250 N
N = 500 rpm
d = Diameter of Rotating shaft
𝑻 =
𝑷×𝟔𝟎
𝟐𝝅𝑵
=
𝟑𝟕𝟐𝟓𝟎×𝟔𝟎
𝟐×𝟑.𝟏𝟒×𝟓𝟎𝟎
= 𝟕𝟏𝟏. 𝟕𝟖 𝑵𝒎
𝑻 = 𝟕𝟏𝟏𝟕𝟖𝟎 𝑵𝒎𝒎 (1)
Now,
𝑇 =
𝜋
16
× 𝜏 × 𝑑³
711780 =
𝜋
16
× 42 × 𝑑³ (2)
Here, material is Mild steel. Tensile stress of MS is 42 N/mm².
So, from the above equation (2) diameter of rotating shaft achieved,
d³ = 86354.86
d = 44.20 say 44 mm (3)
also length of rotating shaft can take 150 mm.

UCET Page 54
6.7.3.2 Design of Connecting rod:-
Figure 6.10: Connecting rod
Figure 6.11: Cross section of connecting rod
Take Length of connecting rod = 300 mm.
Width of section B = 4t.
Depth of Height of section H = 5t.
t = Thickness of flange and web of section.

UCET Page 55
𝐈𝐱𝐱 = 𝟒 𝐈𝐲𝐲 (4)
Where,
Ixx = moment of inertia of section about X-X axis.
Iyy = moment of inertia of section about Y-Y axis.
Area of section,
𝑨 = 𝟐 𝟒𝒕 × 𝒕 ± 𝟑𝒕 × 𝒕 = 𝟏𝟏𝒕² (5)
𝑰𝒙𝒙 =
𝟏
𝟏𝟐
[𝟒𝒕 𝟓𝒕 𝟑
∓ 𝟑𝒕(𝟑𝒕)³] =
𝟒𝟏𝟗
𝟏𝟐
𝒕⁴ (6)
𝑰𝒚𝒚 = 𝟐 ×
𝟏
𝟏𝟐
× 𝒕 𝟒𝒕 𝟑
±
𝟏
𝟏𝟐
× 𝟑𝒕 × 𝒕 𝟑
=
𝟏𝟑𝟏
𝟏𝟐
𝒕⁴ (7)
𝑰𝒙𝒙
𝑰𝒚𝒚
=
𝟒𝟏𝟗
𝟏𝟐
×
𝟏𝟐
𝟏𝟑𝟏
= 𝟑. 𝟐 (8)
Now,
T = 711780 Nmm
Fc = T/r = 32323.63 N (9)
Therefore,
Buckling load Wb = Fc x F.S.
= 32353.63 x 6 (Take Factor of safety 6)
= 194121.78 N (10)
Radius of gyration about x axis,
𝑲𝒙𝒙 =
𝑰𝒙𝒙
𝑨
= 𝟏. 𝟕𝟖𝒕 (11)
Now, according to rankine’s formula,
𝑾𝒃 =
𝝈𝒄𝑨
𝟏 ± 𝒂(
𝑳
𝑲𝒙𝒙
)²
𝟏𝟗𝟒𝟏𝟐𝟏. 𝟕𝟖 =
𝟑𝟐𝟎×𝟏𝟏𝒕²
𝟏±
𝟏
𝟕𝟓𝟎𝟎
(
𝟑𝟎𝟎
𝟏.𝟕𝟖
)²
(12)
From the above equation (12) t can be determine,
t = 7.66 say 8 mm (13)

UCET Page 56
Thickness of flange and web of section = t = 8 mm
Width of section B = 4t = 32 mm
Depth or Height of section H = 5t = 40 mm
These dimensions are at the middle of the connecting rod. The width B is
kept constant throughout the length of rod, but depth H varies. The depth near
the big end is kept as 1.1H to 1.25H
and depth near the small end is kept as 0.75H to 0.9H.
So,
Depth near the big end H1 = 1.2H = 1.2 x 40 = 48 mm
Depth near the small end H2 = 0.85H = 0.85 x 40 = 34 mm
6.7.3.3 Design of Big end Bearing:-
Let,
dc = Diameter of big end bearing
lc = Length of big end bearing = 1.3 dc
pbc = bearing pressure = F/A =
32353.63
48×32
= 21 N/mm²
Load on the big end bearing,
= projected area x Bearing pressure
= dc.lc.pbc
= dc x 1.3dc x 21 = 27.3 dc² (14)
Now,
27.3 dc² = Fc = 32353.63 N
dc² = 1185.11
dc = 34.42 say 35 mm
and
lc = 1.3 dc = 44.75 say 45 mm

UCET Page 57
6.7.3.4 Design of Small end Bearing:-
Let,
dp = Diameter of small end bearing
lp = Length of small end bearing = 2 dp
Pbp = bearing pressure = F/A =
32353.63
34×32
= 30 N/mm²
Load on the small end bearing,
= projected area x Bearing pressure
= dp.lp.pbp = 60 dp² (15)
Now,
60 dp² = Fc = 32353.63 N
dp² = 539.22
dp = 23.22 say 24 mm
and
lp = 2 dp = 48 mm
6.7.3.5 Calculation for the Vibration of Membrane:-
Take Vibration Frequency about 55 Hz.
So, Angular velocity of membrane given by the following equation,
𝝎 = 𝟐𝝅𝒇 = 2 x 3.14 x 55 = 345.5 rad (16)
Now, Linear velocity of membrane,
V = rω = 22 x 345.5 = 7598.8 mm/s = 7.598 m/s (17)

UCET Page 58
Figure 6.12: Cross section of membrane
S = r.θ (18)
Where,
S = Vibration Amplitude = 2.54 cm
R = Radius of Membrane = 12 cm
θ = Angle of Rotation
From the equation (18),
Angle of Rotation can be determine,
𝜽 =
𝑺
𝒓
= 𝟎. 𝟐𝟏𝟏𝟔 ×
𝟏𝟖𝟎
𝝅
= 𝟏𝟑° (19)
Time required to complete one cycle,
T = 1/f = 1/55 = 0.018 sec (20)

UCET Page 59
Chapter 7
Conclusion

UCET Page 60
With the help of single 3 phase motor, different membrane series can be vibrated. So
power consumption to be minimized. Complicate vibration excitation mechanism is
removed by the MVSEP. No torsional spring requirement and simple crank shaft and
connecting rod mechanism. MVSEP technology able to create a shear rate around 500,000
s¹ which is five times higher than the maximum shear in VSEP operation and 50 times
higher than the maximum shear in cross flow vibration.99 % of total energy utilized is
converted to shear in cross flow separation. Formation of cake layer is minimized up to the
bottom layer. Concentration polarization is effectively controlled at the membrane side.
Scaling and Fouling is to be minimized. Replacement cost of the membranes is to be
minimized.

UCET Page 61
Reference:-
1. Environmental Challenge Facing by Industries, Dr. Mahmoud M. EI-Halwagi, Texas
A&M University.
2. http://www.kochmembrane.com/getattachment/Learning-Center/Configurations/What-are-
Spiral-Membranes/KMS_Spiral_Configuration_Illustration.png.aspx
3. http://www.water-technology.net/projects/perth/images/4.jpg
4. http://www.avistatech.com/photos/laboratory_cleaning/thumbs/Fouled%20membrane%20
open.jpg
5. http://www.lenntech.com/images/Avista/Avista-ro-dirty.jpg
6. Evaluation of VSEP to Enhance Water Recovery During Treatment of Brackish Water and
RO Concentrate, Mark M. Benjamin and Wei Shi, Dept. of Civil & Environmenta
Engineering, University of Washinhton, Seattle, WA.
7. A Brief Review of Reverse Osmosis Membrane Technology, Michael E. Williams, Ph. D.,
P.E.
8. Rverse Osmosis Membrane Fouling, David Paul, Farmington, USA.
9. Cleaning Your RO by Wayne T. Bates, www.membranes.com
10. Scale-up Design of a Spacer-Filled Disk-Type Membrane Module Using CFD, R&D
Center for Membrane Technology and Dept. of Chemical Engineering, Chung Yuan
University, Taiwan.
11. http://www.eco-web.com/edi/img/090714-2.gif
12. http://www.aquaticpoolsupply.com/wpcontent/uploads/2011/08/pacfab_mytilus_fmy_50_f
ilter_cartridge_fc-19203.jpg
13. http://www.traderscity.com/board/userpix36/18173-water-treatment-sand-filter-media-
1.jpg
14. http://blog.poolproducts.com/wp-content/uploads/2012/07/filter-diagram-cartridge-
300x300.jpg
15. http://www.lenntech.com/images/desalination/general/revers1.jpg
16. http://www.mtrinc.com/images/faq/spiral.gif
17. http://www.lenntech.com/images/tubula9.jpg
18. http://www.geap.co.nz/nnz/cmsresources.nsf/0/B5D4F59F9C8145BDC12572E4004CD73
9/$File/PlateFramemembrane.jpg

UCET Page 62
19. http://www.mdpi.com/water/water-05-00094/article_deploy/html/images/water-05-00094-
g002-1024.png
20. Membrane Filtration Handbook by Jorgen Wagner Nov 2011.
21. Prevention and control of Membrane Fouling, Dr. ACM Franken, Membrane Application
Centrum Twente B.V June 2009.
22. http://www.lenntech.com/antiscalants.htm
23. http://www.kochmembrane.com/Learning-Center/Membranes/Technologies/What-is-
Ultrafiltration.aspx
24. http://www.dow.com/product/water%20solution
25. Doshion Veolia Water Solution(DVWS). www.doshion.com
26. ―How Reverse Osmosis Filter Systems Work and What They Do,‖
http://espwaterproducts.com

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