kirloskar corrocoat gfc casestudy
TRANSCRIPT
IMPROVING LIFE AND
EFFICIENCY OF PUMPS &
SYSTEMS USING
COMPOSITE COATINGS
Cost of energy for pumping water constitutes an important element of
utilities for industries. The authorities responsible for pumping water
are among the biggest consumer of electricity and in some locations
largest single consumer. Cost of electricity in pumping the water over
a period of its' life amounts to 90-95 % of the total cost, while 5-
10% relates to purchase of pump and maintenance cost.
In any pumping system, over the years, the hydraulic passages of
casings and impeller vane shape gets damaged due to wear, tear and
corrosion, also the clearance in wearing rings increases substantially.
All these damages lead to head & flow losses and ultimately
deteriorate hydraulic performance. Due to this deterioration of
performance the power consumption increases putting pressure on
energy demand due to inefficient operation of pump.
In order to keep balance of energy demand, frequent shutdown of
plants are essential. These frequent shutdowns lead to production
loss and lower utilization of scarce energy resource. To overcome
these situations it is essential to have a longer period between
shutdowns and minimal cost for maintenance.
To achieve these objectives high technology composite resin systems
along with glass fiber matting technology are available which can be
used to refurbish and restore the hydraulic passages of the pump.
These passages can be applied with specially formulated energy
improvement coating, “Fluiglide.” The Fluiglide system helps to
achieve very low coefficient of friction as compared to original metal
substrate. With this, not only performance is improved
over existing one but the life of equipment is also increased.
Over a period of last 8-10 years number of pumps have been applied
with Fluiglide systems. These systems have following attributes:
They limit the effect of mechanical damage.
They resist chemically aggressive constituents in the service
environment.
They provide a barrier to prevent permeation of corrosion ions to
the substrate.
They provide low coefficient of friction.
Most of the pumps, medium and large size, can be effectively treated
with polymer resin systems, both old and new. Before deciding the
specific polymer system for the pump under consideration its
operating and service conditions are studied. Based on the operating
and service conditions a appropriate resin system is selected to give
protection to the substrate from corrosion and /or erosion. This resin
system is then over-coated with “Fluiglide.”
These coatings are known to be effective by two established
qualities:
1. The reduction in surface roughness. (Refer Illustration No. 1)
2. The hydrophobic nature of coating. (Refer Illustration No. 2)
1. The reduction in surface roughness :
It is well known that surface roughness has substantial bearing on
flow characteristics. A rough surface introduces micro or even macro
turbulent eddies in the boundary layer causing an increase in velocity
gradient. This velocity gradient creates resistance in passage of flow.
With the application of coatings surface roughness is reduced by
manifolds, thereby allowing the flow to be comparatively less
turbulent. Due to this phenomenon overall performance i.e. head and
flow characteristics increases.
For example the surface roughness of a cast iron substrate is Ra 18.8
microns while surface roughness of Fluiglide coating is as low as Ra
0.4 to 0.08 microns (Refer illustration no. 1). Due to lower coefficient
of friction, between the fluid and the coating and hydrophobic nature
2. The hydrophobic nature of coating:
When the attractive forces between the substrate and the water
molecules exceed the cohesive forces in the fluids, then the water or
other media will spread across the surface until a state of equilibrium
is reached between the two.
Therefore, where the surface energy is high, low contact angles will
be achieved and where surface energy or attraction is low, the high
contact angles will result in large gradients in velocity between the
mainstream flow and the boundary layer. In case of aqueous media,
materials which have low surface attraction are hydrophobic and repel
water, will result in lower frictional losses than surfaces which are
highly attractive to water molecules.
As all common untreated metals have relatively high attraction
energies wetting out of the surface with aqueous media and the
consequent low contact angle is readily achieved. A substantial
reduction in boundary layer friction can therefore be achieved by
utilizing a coating, which is hydrophobic. The effects of these are
demonstrated below
It has been observed that efficiency gains from coating are presented
in two different ways:
An increase in flow (water output) for the same input energy
(electrical consumption).
A reduction in input energy for the same water output.
It is possible to obtain the combination of these two extremes and
this is usually the case. The actual improvements achieved depend on
various factors including the specific speed of the pump.
A lot of experimentation has been carried out by coating small as well
as medium and large size pumps and testing them. After the study it
has been established that low flow pumps having delivery sizes upto
100-mm size are not amenable to substantial efficiency enhancement
by coating. But pumps of delivery sizes larger than 100 mm and
impellers with outlet widths larger than 20 mm show a remarkable
improvement in efficiency, and discharge rates and head development.
The life of coating is generally more than 5 years. The coating can get
damaged only by external causes like foreign matter with sharp
corners and edges getting into the pump and passing through it or by
operation of the pump under cavitation due to inadequate available
NPSH or cavitation due to re-circulation during operation at part
capacities.
GLASS FLAKE TECHNOLOGY
TORTUOUS PATH
Tortuous path for corrosive ion
Layers of glass flakes
Coating
SUBSTRATE
• The development of in-house Glassflake technology has allowed for the production of the inner more uniform and consistent Glassflake
• Glassflake can now be made at sub micron thickness
ADVANCED GLASSFLAKE TECHNOLOGYADVANCED GLASSFLAKE TECHNOLOGY
COMPARISONS OF PHYSICAL PROPERTIES
COMPARISONS OF PHYSICAL PROPERTIES
ALUMINIUM
BRONZE
CAST IRON
MILD STEEL
POLYESTER COMPOSITE
EPOXY COMPOSITE
DENSITY TENSILE STRENGTH
MODULUS OF ELASTICIY
SHEAR STRENGTH
lbs/cuft kg/m²
168
557
458
491
104
94
2698
8920
7300
7860
166
1550
22
33
32
47
117
90
155
230
220
325
807
621
10
15
17
30
18
17
3.0
4.5
26.1
5.0
12.0
9.0
1.9
31
180
35
83
62
70
103
120
210
123
120
PSIx10³ MPa PSIx106 MPaGPa PSIx103
• Excellent temperature resistance
• Excellent chemical resistance
• Excellent dry and immersed adhesion
• Low permeation rate
• Applicable over a wide range of substrates
• High abrasion resistance
• Machinability
BENEFITS/PROPERTIES OF
GLASSFLAKE COATINGS
BENEFITS/PROPERTIES OF
GLASSFLAKE COATINGS
• Dimensional stability
• Reparability
• Impact resistance
• High tensile strength
• High resistance to cathodic disbondment
• Durability, very long service lives
• Very low VOC
• Cost effective
Sr. No. Liquid Type and
Name
Description Specifications Attributing Properties of
Coating
1 Clear Water
Fluiglide System
Dry Film
Thickness
DFT 1000 microns Avg. Tolerance minus
100 micron
Dry Film Thickness
Base Coat A medium viscosity pre accelerated
Bisphenol ‘A’ polyester glass flake
compound, cured by the addition of organic
compound.
Adhesion layer to ensure
proper bonding with
respect to Base Metal
Intermediate Coat A heavy Built Glass Flake coatings based on
low reactivity , Bisphenol ‘A’ Polyester resin
pre accelerated, A two pack resin system
sing organic peroxide
Anticorrosion Layer
Top Coat A cold cured highly modified chemically
resistant, two-pack resin system filled with
stabilizing enforcement to reduce cold flow
characteristics. The coating should have
good gloss with waxy appearance when
cured.
Efficiency Improvement
Layer
2 Raw Water , ETP
and Sewage
Fluiglide E System
Dry Film
Thickness
DFT 1500 microns Avg. Tolerance minus
100 micron
Dry Film Thickness
Base Coat A solvent free, high build, two or three pack
epoxy coating with excellent erosion
resistance, toughness and outstanding
erosion properties.
Adhesion layer to ensure
proper bonding with
respect to Base Metal
Intermediate Coat A solvent free, two or three pack epoxy
coating with excellent erosion resistance,
toughness and outstanding erosion
properties.
Anticorrosion Layer
Top Coat A cold cured 100 % solid epoxide specially
modified to give roughness amplitude of
0.08 microns.
Efficiency Improvement
Layer
PUMPS
After 4 years sea-water service
After refurbishment with Corrocoat Corroglass
After 7 years service
PUMPS
After 7 years service
After refurbishment with Corrocoat Corroglass, note the wear ring areas using specialist casting techniques
After 4 years sea-water service
Case Study
Background:
20”X24” horizontal split casing pumps, 8 Nos. are working for supplying
cooling water. These pumps were designed for 70.4 meter head and
4500 M3 / Hr. flow at 90.5% efficiency. These pumps were installed in the
year 1985. During the course of operation it was observed that these pumps
were operating at lower head at 50.0 meter and higher flow consuming more
power and operating with the danger of cavitation.
The customer considered trimming of impeller to suit the actual site duties of
4500 M3 / Hr at 50.0 meter head. They approached the manufacturer and
informed that with such a severe trimming of impeller there would be loss of
efficiency. The trimming was carried out and this resulted in deterioration
of efficiency.
At this point customer approached us. A proposal was
put forward by us to restore the new duty point efficiency to
original level by modification to the casing and application of energy
efficient Fluiglide system. Customer placed an order for refurbishment
and coating of one pump.
Following activities were involved in the process:
1. Test the pump at factory with trimmed impeller and establish the
existing performance.
2. Design and carry out modification in the casing to suit new trimmed
impeller.
3. Application of energy efficient coating.
4. Test the pump after modification and coating with Fluiglide system to
establish the restoration of efficiency.
5. We decided to carry out CFD analysis of as built design and also with
modification (before carrying out actual modification on pump) to
give confidence to the client about the proposed modification in
design.
Performance parameters: Performance
Parameters
Original
Performance
Performance
after
trimming of
impeller
After
refurbishment
& application
of coating
Flow in m3/Hr 4500 4500 4523.4
Head in m 70.4 50 50
Speed in RPM 990 990 990
Pump input in kW 953.31 729.45 671.64
Best efficiency 90.5% 84% 91.23%
• Due to restored dimensions inside casing and improved efficiency of
91.23% the modified pump consumes pump-input power of 671.64 kW only.
• Power saving 57.81 kW.
• This saving converted on yearly basis is 506415.6 kwH and is for one pump.
• For 8 pumps working it would be 40,51,324.8 kWH per year. This meant
saving of Rs.22,78,867 annually.
• Pay back period for re-furbishment worked out to be only 2-3 months.
GU
NA
PU
MP
IN
PU
T (
)
ACHIEVED
DT-
DISCHARGE ( )
HEAVY WATER BOARD, MANUGURU
O/A NO./ITEM NO.:-
IMP. DIA./MAT.:-
CLIENT
CONSULTANTS/
SERVICE
INDENTOR
PROJECT
0
10
10J0V0050/01.00
-- mm --
COOLING WATER
--
--
1000 2000 3000
70
PU
MP
EF
FIC
IEN
CY
(
% )
30
20
40
50
60
80
90
400
2000
600
GUARANTEED DUTY POINT
990
--
--
729.5
84
4500
50
MIN. SUBMERGENCE13/11/1999
RECOMMENDED PRIME MOVER
FULL LOAD SPEED
REQUIRED NPSH
DISCHARGE Q
PUMP EFFICIENCY
PUMP INPUT
PUMP HEAD
4000 5000
m3/hr
H
6000 7000
mm
rpm
kW
%
m
kW
m3/hr
m
0
2
SPECIFIED
TE
ST
WIT
NE
SS
ED
BY
:
NP
SH
R I
N (
)
6
4
8 m
10
DA
TE
:--
--D
RA
WN
BY
:
17
/11
/00
DA
TE
:
ACHIEVED
THIS CURVE RELATES TO THE LIQUID OF SP. GRAVITY
KIRLOSKAR BROTHERS LIMITED, PUNE (INDIA)
20/24 CME (DV)
50PU
MP
HE
AD
(
)kW
30
40
60
m 70
80
85
*PERFORMANCE CURVE OF
PUMP AS DELIVERED TO KBL*
CORPORATE RESEARCH & ENGG.
DIVISION
mm
RKP/20173/0
SPECIFIED
SPECIFIED
1
SUC.
CURVE NO.
600
DA
TE
:
AP
PR
OV
ED
BY
:C
HE
CK
ED
BY
:
17
/11
/00
DA
TE
:
RG
PJT
K
17
/11
/00
500DEL. mm
GU
NA
PU
MP
IN
PU
T (
)
DT-
DISCHARGE ( )
HEAVY WATER BOARD, MANUGURU
O/A NO./ITEM NO.:-
IMP. DIA./MAT.:-
CLIENT
CONSULTANTS/
SERVICE
INDENTOR
PROJECT
0
10
10J0V0050/01.00
-- mm --
COOLING WATER
--
--
1000 2000 3000
70
PU
MP
EF
FIC
IEN
CY
(
% )
30
20
40
50
60
80
90
400
2000
600
GUARANTEED DUTY POINT
990
1080
--
673.76
91
4500
50
MIN. SUBMERGENCE13/11/1999
RECOMMENDED PRIME MOVER
FULL LOAD SPEED
REQUIRED NPSH
DISCHARGE Q
PUMP EFFICIENCY
PUMP INPUT
PUMP HEAD
4000 5000
m3/hr
H
6000 7000
mm
rpm
kW
%
m
kW
m3/hr
m
0
2
TE
ST
WIT
NE
SS
ED
BY
:
NP
SH
R IN
( )
6
4
8 m
10
DA
TE
:--
--D
RA
WN
BY
:
17
/11
/00
DA
TE
:
THIS CURVE RELATES TO THE LIQUID OF SP. GRAVITY
KIRLOSKAR BROTHERS LIMITED, PUNE (INDIA)
AFTER REFURBISHING OF CASING AND COATING OF PUMPS
20/24 CME (DV)
40PU
MP
HE
AD
(
)
kW
30
20
60
m 80
100
85
*PERFORMANCE CURVE OF
*
CORPORATE RESEARCH & ENGG.
DIVISION
mm
RKP/20172/0
1
SUC.
CURVE NO.
600
DA
TE
:
AP
PR
OV
ED
BY
:C
HE
CK
ED
BY
:
17
/11
/00
DA
TE
:
RG
PJT
K
17
/11
/00
500DEL. mm
View of Bottom & Top Casing prior to blasting…………..
View of coated components, top casing……
View of coated components, bottom casing…….
View of coated Impeller after coating & balancing…..
Conclusion:
During last 5-6 years our company has used
Fluiglide coating systems on hundreds of
medium and large size pumps resulting in
efficiency gain of 1-3 points depending on
type of pump & the specific speed, in case of
new pumps. This gain in efficiency was over
and above designed one.
Also hundreds of old pumps have been
refurbished to restore the shapes of hydraulic
passages near to its original one and
application of Fluiglide systems have resulted
into gain in efficiency of 4-6 points and
improvement in head – flow characteristics
over its existing one during the operation in
the plant.
As the efficiency enhancement achieved with
Fluiglide treatment is expected to be retained
for a period of at least 3 years, the benefits
achieved is expected to continue for a
minimum period of 3 years. This has been
established by inspecting the pumps after
opening them during shutdown after a period
of 4-5 years.
The concept of composite resin systems could
be advantageously used for internal lining of
pipelines to combat corrosion on internal
surface of pipes, which takes place mainly
due to depositions of chlorides and sulphates.
The depositions over a period of time increase
frictional head by reducing area of pipes.
Composite coatings combined with appropriate
refurbishing techniques have potential to provide
pumping solutions which were so far not available.
This is a concept and not a product, which should
be propagated across the length and breadth of our
country to arrest huge national loss taking place
due to corrosion and wear of pumping and other
equipments.
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