IPPTA ZONAL SEMINAR
6th & 7th of Aug’2015
Hotel Courtyard
Marriott, Ahmedabad
RAJESH MAGAR . V
CRI Pumps Pvt. Ltd., Coimbatore
TITLE :
“LIFE CYCLE COST - OF
CENTRIFUGAL PUMPS
IN PAPER & PULP
INDUSTRIES
FOR MAXIMISING PROFITS”.
Definition :
The Life Cycle Cost (LCC), of
any piece of Equipment is
the total “lifetime” cost…
which starts from Purchase,
Install, Operate, Maintain
and Dispose of that
Equipment.
INTRODUCTION :
Centrifugal pumps are the most common Pump type and
predominantly used in the Pulp and Paper Industries.
Applications :
- Paper stock and Fibrous Pulp
- Fan Pump
- White, Black & Green Liquors
- Process & Fibrous Effluents
- Dewatering & De-inking Liquors
- Air Entrained Liquors
- Corrosive and Non-Corrosive Liquors
- All corrosive and Non corrosive Effluents
- Liquors with Suspended solids
Conventional Approach of Purchasing Equipment :
Engineering : Are often overly conservative when specifying and
selecting pumps & generally advice a redundant equipment i.e.
Stand-by pump to avoid costly failures.
Purchase Dept : Buys lower grade equipment to get favorable
purchase price variances.
Project engineering: Builds plant with a 6 month view of successfully
running the plant only during start-ups, rather than long term view
of low cost operation.
Process Engineering: Operates equipment using a philosophy that
the equipment is capable of operating at 150% of rated condition.
Maintenance: Defers required corrective/preventive actions to
reduce budgets & thus long term cost increase because of neglect for
short term management gains.
Beyond the purchase price:
Pumps are the Heart of any Process Industry & generally
Industrial Pumping systems often have a lifespan of 15 to 20 years.
This means that a poor decision can haunt a user for many years.
Pumps need to be installed, maintained, and sometimes repaired.
They also require electricity (or other driving means) to run. All too
often, the final decision is dictated by one of the more insignificant
costs of the total LCC, namely, the “Purchase Price”.
Generally, in today’s work culture, people only consider the
procurement cost neglecting other important costs. Here the
procurement cost of an equipment is like a tip of iceberg which does
not show the underlying hidden cost. The consideration of only the
tip of iceberg is hazardous as the difficulties and hazards generally
are hidden in the inside as depicted below :
Purchase cost - Tip of
the iceberg
Why should an Organization care about LCC…?
As most organizations only consider the Initial purchase and
installation cost of the equipment.
 It is in the fundamental interest of the Plant designer to
evaluate the Life Cycle Cost, of different equipments before
installation of new plant or expansion.
 In today’s competitive market, organizations must continuously
seek cost saving methods, which will improve their profitability.
 LCC also helps in developing awareness about environmental
impact of their business and conserving energy , to reduce
emission, preserve natural resources and reduce carbon foot
print.
According to the Hydraulic Institute life-cycle-costing for
pumps is calculated as following :
LCC = Cip + Ce + Cm + Co + Cs + Cenv + Cin wherein,
Cip = Initial purchase price (pump, system, pipe, auxillary services)
Ce = Energy costs (predicted cost for system operation, including pump
driver, controls, and any auxillary services)
Cm = Maintenance and repair costs (routine and predicted repairs)
Co = Operation costs (labor cost of normal system supervision)
Cs = Downtime costs (loss of production)
Cenv = Environmental costs & disposal costs (contamination from
pumped liquid and auxiliary equipment)
Cin = Installation and commissioning cost (including training).
Note :
Each of these values vary widely in significance from application to application, in
Process Industries such as Paper & Pulp, Petrochemical (or) Pharmaceutical.
Pie-Chart depicting the Total LCC :
It is noticed that the Initial capital costs represent only a
small fraction of the total LCC for process equipment.
“Energy Cost” and “Maintenance costs” typically remain
the highest Single source of cost over a pump’s life.
I ) Energy Costs (Ce) :
The energy savings potential for pumping systems within the Pulp and
paper industry is estimated at over 6,000 GWh/year, yet capital
expenditures for pumping-related energy efficiency improvement
projects are very minimal.
Energy consumption - is often one of the larger cost elements and
dominates the LCC, especially if pumps run more than 5000 hours, per
year.
The Power input for a Pump is given by the following equation :
P = Q x H x s.g. [kW]
367 x hp
where P = power, Q = rate of flow (m3/hr), H = head (m) or (ft),
hp = pump efficiency and s.g. = specific gravity of liquid
Reducing Energy Costs can be achieved by the following 3
methods :
a) Replace Old Inefficient Pumps by New Efficient Pumps
b) Energy Savings through Pump Control
c) Proper Pump selection & System Changes
1 (a) Replace Old Inefficient Pumps by New Efficient Pumps :
Pump specifiers and purchasers are often overly conservative when specifying
and selecting pumps. Often pumps are specified for planned future production
increases, resulting in some Inefficiencies.
Application : Unbleached Pulp
Duty Parameters :
Flow
Head
SG of liquid
Model
Efficiency %
BKW
Motor Rating
Speed
MOC
Existing Pump
Proposed CRI Pump
440 m3/hr
440 m3/hr
14 Mtrs
1.03
14 Mtrs
1.03
APP-C-31-150
ECC - 8 x 6 x17
62 %
70%
27.8 ( Approx.)
24.7
37 KW
30 KW
1450 RPM
CI / SS 316
1450 RPM
CI / SS 316
Note : The difference in Bkw - 3.1 Kw. It is estimated that the savings per annum will be
approximately Rs. 1,35,780/- by replacing the Old Pump with New Energy Efficient Pump .
Considering commercial energy price at Rs. 5/- kwhr , the ROI will be approximately 9
months !!
1 ) Paper & Pulp Pumps (CRI Make - ECP) Suitable
for Pulp Consistency upto 8%
Operating Conditions :
Centrifugal Back Pull-out with
Open Impeller .
Head
: to 95 mts
Capacity : to 3200 m3/hr
RPM - 1000 & 1500
Working Pr. – 10 Bar
Temperature - 232 deg C
MOC Offered – SS 316, 304,
CI & any other alloys of Steel
2 ) PROCESS Pumps (CRI Make -ECC) Suitable for
Pulp Consistency upto 4%
Manufactured strictly to ANSI
B 73.1 , with Semi-Open Impeller
Operating Conditions :
Head
: Upto 120 mts
Capacity: to 1000 m3/hr
RPM - 750 to 3600
Working Pr. - 10 to 16bar
Temperature - -20 to + 200 deg C
MOC Offered – SS 316, 304,
CD4MCu, Hastealloy, Alloy 20, &
any other alloys of Steel.
3 ) SLURRY
Pumps (CRI Make - ECH) Suitable for
For Applns. such as Green liquor, white liquor, and lime mud
abrasive liquids (all products of the chemical pulping process).
Pump Type : End suction Centrifugal Pump Back Pull-out
Pump with Closed Impeller.
Operating Conditions :
Head
: to 90 mts
Capacity: Upto 3200 m3/hr
RPM - 750 to 1450
Working Pr. – 10 bar
Temperature - 200 deg C
MOC Offered – Hichrome,
Nihard & Rubberlined
I (b) Energy Savings through Pump Control :
(i) Use of Variable Speed Drives (VFD) to control pump flow rate or
maintain pressure. Black liquor pumps are often candidates for
variable speed drives because the black liquor viscosity can vary
significantly with relatively minor variation in temperature, thus
altering the Pressure requirements and Pump Performance.
(ii) Use of Power monitors to track motor power usage and/or shut
them down if power deviates. The potential Pumping and Motor
system energy efficiency savings - is equal to 5% of the operating
margins within the pulp and paper industry (DOE* 1998).
(iii) Use of PLC or similar logic controls to monitor - Flows, Pressures,
Power Consumption, Temperature, etc., These are a bit complex and
costly, but allow just a few operators to monitor multiple pumps and
systems.
* US Department of Energy's Office, of Industrial Technologies
I (c) Proper Pump selection & System Changes :
Generally, the pump selection has to always be close to and on the left
hand side of the Best Efficiency Point (BEP). The BEP is the point at which the
pump operates most cost-effectively in terms of both Energy efficiency and
Maintenance considerations. Thus, operation near the BEP minimizes wear to
seals, bearings and other parts.
I (c) Proper Pump selection & System Changes (Cont’d) :
Narrow pipes running through a maze of twists and turns as
shown below- increases the System Head required and in turn,
the Pump power.
Whereas, Larger pipe sizes create less friction for a given flow
rate than smaller pipe sizes. The reduced friction loss reduces the
pressure requirements, but the larger pipe size incurs an extra
initial equipment cost.
Add to that any changes in viscosity, product buildup, or corrosion
on the pipe walls, and the power requirement can climb further.
II) Maintenance Costs (Cm) :
Obtaining optimum working life from a pump requires regular and
efficient servicing. Inadequate maintenance lowers pump system
efficiency, causes pumps to wear out more quickly and increases costs.
Better maintenance will reduce these problems and the most
important – to save energy.
Following are the maintenance Checks :
 Replacement of worn impellers, especially in caustic applications.
 Trimming of Pump impellers
 Bearing lubrication replacement, once annually or semi-annually.
 Inspection and replacement of Gland packing seals
 Inspection and replacement of mechanical seals
 Pump/motor alignment check.
Pump Impeller Trimming :
 Oversized and throttled pumps that produce excess pressure are excellent
candidates for impeller replacement or “trimming,” to save energy and
reduce costs.
 Trimming reduces the impeller’s tip speed, which in turn reduces the
amount of energy imparted to the pumped fluid; as a result, the pump’s
flow rate and pressure both decrease.
 Correcting pump oversizing in Paper Industries can save upto 15% to
25% of electricity consumption for pumping systems.
Open /Stock Impeller
Semi –Open
Closed
Improved Bearing Life (> 50000 hrs) by Using Angular
Contact Bearings at DE & NDE
Existing pump
Single row ball bearing
LLC / CRI Pump
Angular contact paired bearing
Inspection and Replacement of Mechanical Seals :
 Mechanical seal failures accounts for up to 70% of pump failures
in many applications, thus increasing the downtime costs.
 However the most important factor contributing to adequate seal
life is without doubt the use of appropriate STUFFING BOX
design.
 Modern pump stuffing box designs for use in fibre plants are
generally based upon the “Taper or big bore concept”.
Energy Savings Tips for Paper Pulp Industries :
 One straight forward way to increase the efficiency of a pump
system by 2-5% points is to install a higher efficiency motor.
 Another energy-efficient retrofit opportunity, especially for paper
stock pumps, is to replace the pump "stock" impellers with
"process" impellers..
 Slowing a pump's speed will reduce the system pressure and flow,
and therefore the brake horsepower is reduced and the pump
efficiency curve will shift to the left. For example, a 20% reduction
in pump speed will reduce the flow rate by 20%, but the power
consumption will decrease by almost 50%.
 Run LCC calculations for all new pump installations. Existing
pumps should be examined as well.
An experienced Pump Representative / Solutions Providers from
CRI Pumps - can assist with this and help you perform a Pump
Survey (or) a Power Audit, to help identify problems and suggest
potential solutions.
CONCLUSION :
Significant opportunities exist to improve the - Energy
Efficiency and reduce the Life Cycle Costs of Pumping
Systems in the pulp and paper industry by using existing
technologies and proven Practices.
Savings can be optimized by taking a systems approach,
which considers the entire process system and the individual
Equipment, rather than the Purchase cost alone……!!!
THANK YOU……