4 doe case studies

8/13/2019 4 DOE Case Studies

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ENEFITS

Saves 700,000 kilowatt-hours (kWh)

annually

Reduces maintenance costs by

$10,000 per year

Improves equipment life

Increases efficiency

PPLICATIONS

ffluent pump systems are widespread

n the paper industry and can consume

significant portion of the electricity

sed in paper mills. In cases where

multiple pumps are used, a proper

ontrol strategy can improve efficiencynd save energy by optimally matching

he available pumping capacity to the

ystem requirements.

May 2002OFFICE OF INDUSTRIAL TECHNOLOGIES

ENERGY EFFICIENCY AND RENEWABLE ENERGY, U.S. DEPARTMENT OF ENE

FORESTPRODUCTS

BestPracticesProject Case Study


Pump System Optimization Saves Energy and Improve

Productivity at Daishowa America Paper Mill

Summary

In 2000, Daishowa America implemented an improvement project on the effluen

pumping system at its paper mill in Port Angeles, Washington. Because of chronmaintenance issues and rising energy costs, personnel at the Port Angeles milldecided to review the pumping system for optimization opportunities. The reviewled mill personnel to implement a system-level project that decreased the pumpsystems energy consumption. The project involved the installation of mechanicaAdjustable Speed Drives (ASDs) on two pumps in the mills pumping system. Thproject allowed the system to operate more effectively, and resulted in annual enesavings of $32,000 and 700,000 kilowatt-hours (kWh). The project also eliminatemany problems that led to excessive maintenance costs and resulted in annualmaintenance savings of $10,000. Because the project received partial funding frthe Northwest Energy Efficiency Alliance (NEEA), the total mill project cost was$60,000. With a total annual savings of $42,000, the simple payback was slightly m

than 15 months.

DAISHOWA AMERICASPORTANGELESPAPERMILL


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Project Results

The implementation of the project has improved the operation of the effluent pumping system andresulted in significant energy savings for the Port Angeles mill. With the newly configured pumpingsystem, the mill no longer depends on bypass and throttling valves to control the pumping system.The ASDs can vary the pump speed to match the pump output capacity with the mills required

process flow rate. The new configuration allows the mill to baseload only one of the pumps whileoperating the other one at partial load. By not operating both pumps at full capacity, cavitation andvibration have been drastically reduced. Because they are uncoupled from the pump motors, theASDs allow the pumps to start gradually, which eliminates water surges and pipe hammer. This, inturn, lessens stress on the systems piping and internal components, reduces maintenance needs,and prolongs equipment life.

The systems flow rate has declined by 31 percent, or 2,200 gpm from 7,000 gpm, and rarely exceeds4,800 gpm. Power demand has declined from 142 kW to 62 kW. The reduction in the systems flowrate and power demand are due to the installation of the ASDs, the rebuilt pumps, and the operationof one pump at partial load versus two pumps at full load. The mill saves $32,000 and 700,000 kWhin annual energy costs, and $10,000 per year in maintenance costs. Because of a cost sharing

and installing spacers between the motors and the pumps. No inverter-duty motors, extensive

rewiring, or reconfiguration of the pump stations were necessary. Second, ruggedness and a lackof sensitive electronic parts made these mechanical ASDs less prone to maintenance problems inan environment such as the mills effluent treatment process. Because the mills system is a medium-voltage application, these ASDs were less costly than comparable VSDs. Finally, these ASDs aremechanical, so there are no direct connections between the motors and pumps; this substantiallyreduces vibration and allows softstart capability.

ANEFFLUENTPUMP WITH THEMECHANICAL ASD


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MOTOR CHALLENGEProject Fact Sheet

A Business Case Study

BENEFITS

Reduced energy consumption

by almost 44%

Reduced cleaning and

maintenance

Extended equipments

expected life

Increased system capacity

25 %

Decreased noise

TOWN OF TRUMBULL PUMP OPTIMIZATION PROJECTYIELDS$60,000 NETPRESENTVALUE

The Town of Trumbull was looking for a way to increase the operating perfor-mance of one of its 10 sewage pumping stations. Built in 1971, the stationconsisted of twin sewage handling pumps (40-hp direct drive, wound rotormotor) vertically mounted below ground, handling 340,000 gallons of raw sew-

age per day. The system used one pump to handle the entire peak flow undernormal operation, and used the second pump in only extreme conditions. Eachpump rarely operated more than five minutes at a time. The system experi-enced frequent breakdowns, occasional flooding, and sewage spills.

Decision

With the help of ITT Flygt Corporation (new-pump manufacturer), engineersinvestigated total system performance and decided to add a smaller, 10-hppump with direct online motor starters and a level control system with floatswitches. The new pump handles the same volume as the original pumpsduring non-peak periods, but runs for longer periods of time. The old pumpshandle infrequent peak flows. The 2 compressors for the bubbler level control

system and the 2 circulating pumps for the old motor control system were alsoeliminated, and lighting efficiencies were implemented.

OFFICE OF INDUSTRIAL TECHNOLOGIESENERGY EFFICIENCY AND RENEWABLE ENERGY U.S. DEPARTMENT OF ENER

Net Present Value: $60,000

Internal Rate of Return: 52%

Payback: 1.9 years

TOTALVALUE ADDED

EXISTING40-HP PUM PMOTOR


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1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

Motor Challenge, administered by Office of Industrial Technologies, ivoluntary partnership program witindustry to promote the use of eneefficient electric motor systems.Thousands of industrial partners hajoi ned Motor Challenge and areimproving their, and in turn, the Nacompetitiveness and efficiency.

Motor Challenge assists the OITIndustries of the Future by identifyinear-term gains in energy efficiencthese industries can achieve byadopting existing technologies.

PROJECT PARTNERS

Town of TrumbullTrumbull, CT

ITT Flygt CorporationTrumbull, CT

FOR ADDITIONAL INFORMATIO

PLEASE CONTACT:

The OIT Information ClearinghousePhone: (800) 862-2086Fax: (360) 586-8303http://www.motor.doe.gov

Visit our home page atwww.oit.doe.gov

Please send any comments,questions, or suggestions to

[email protected]

Office of Industrial TechnologiesEnergy Efficiencyand Renewable EnergyU.S. Department of EnergyWashington, D.C. 20585

This decision produced the following results:

u Reduced energy consumption by almost 44%due to: lower outflow rate reduced losses in the piping system lighting system upgrades elimination of the bubbler level control and cooling water pumps

u Reduced cleaning and maintenancerequirements (supplies and labor) andassociated downtime eliminated the need to replace 2 mechanical seals per year new, submersible pump is much easier to swap out if repair/replacement

is neededu Extended equipments expected lifedue to longer operating times and

reduced power inputu Increased system capacity 25%, potentially deferring need for additional

pump stationsu Decreased noisefrom new pump, improving relations with local residents

These modifications can be easily replicatedat other sites (new sites or retrofit).A new pump site under construction in Trumbull is using the submersible pump

technology and saving an additional $10,000 - $12,000 by eliminating the need todig a second hole.

Value Added:Equipment Cost, fully installed: $12,000

Annual Savings:

Energy savings $2,600 31,900 kWh/yr

Maintenance Savings:

Supplies $1,800 2 seals/yr * $900 each

Labor $1,800Total $6,200

Rationale

($Thousands) Time (years 0 - 12) (years) 0 1 2 3 4 5 6 7 8 9 10 11 12SAVINGSEnergy 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6Supplies 1.8 1.8 1.8 1.8 1.8 1.8 1.8 1.8 1.8 1.8 1.8 1.8Labor 1.8 1.8 1.8 1.8 1.8 1.8 1.8 1.8 1.8 1.8 1.8 1.8

COST 12.0Incremental (12.0) 6.2 6.2 6.2 6.2 6.2 6.2 6.2 6.2 6.2 6.2 6.2 6.2 savings

Incremental Cashflow Analysis

Time (years 13 - 25)(years cont) 13 14 15 16 17 18 19 20 21 22 23 24 25SAVINGSEnergy 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6Supplies 1.8 1.8 1.8 1.8 1.8 1.8 1.8 1.8 1.8 1.8 1.8 1.8 1.8Labor 1.8 1.8 1.8 1.8 1.8 1.8 1.8 1.8 1.8 1.8 1.8 1.8 1.8

Incremental 6.2 6.2 6.2 6.2 6.2 6.2 6.2 6.2 6.2 6.2 6.2 6.2 6.2Savings

NET PRESENT VALUE $601

INTERNAL RATE OF RETURN 52%

1Cashflows are discounted at 7%

February 1999


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OPTIMIZING PUMP SYSTEMS AT A COAL SLURRYPREPARATION PLANT

Summary

Peabody Holding Company, the largest U.S. coal producer,has completed a project to improve the performance of a coalslurry pumping system at its Randolph Coal Preparation plant.Changes to the coal washing process resulted in cyclone pumpsystems that were larger than necessary to meet systemrequirements. Finding ways to increase the efficiency of these

oversized pump systems was the objective of this MotorChallenge Showcase Demonstration Project. This case studydescribes the performance optimization conducted by theShowcase Demonstration team on one of the six classifyingcyclone pumps. Using a systematic approach, three energy-saving opportunities were identifiedinvolving the motor, belt drive, and pump components of the pumping system. The modificationssaved 87,184 kWh of electricity, equivalent to $5,231 in annual energy cost savings, and overallenergy consumption of the pumping system decreased by approximately 15 percent. Total costs toimplement the project amounted to $15,693 yielding a simple payback of 3.3 years. When performedon each of the remaining five pumps, the performance optimization will result in an estimated 523,000kWh in energy savings and $31,000 in annual energy cost savings.

Company Background

Peabody Holding Company, Inc. generates more than $2 billion in annual revenues by providingpolicy management and strategic planning to the Peabody Group, comprised of 50 coal mining,marketing, and related corporations in the United States and Australia. Together, these corporationsoperate 29 mines and own or operate roughly 12 billion tons of steam and metallurgical coal reservesthroughout the world. Peabody initiated this Motor Challenge Showcase Demonstration project in

order to improve their motorsystems and because of theirheightened awareness of energyefficiency and environmentalconcerns.

Project Overview

The Randolph Coal preparationplant processes and cleansbituminous coal supplied byPeabodys Marissa UndergroundMine, located in west-central Illinoisnear Baldwin, Illinois. The coal isremoved by continuous minersusing the Room and Pillarmethod, a coal extraction technique

CASE STUDYShowcase Demonstration

Randolph Coal Preparation Plant

Project Profile

Industry: Coal Mining

Process: Coal Slurry Separation

System: Cyclone Pump

Technology: Resized Pump,Energy-Efficient Motor


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involving rotary drums that shear coal, shale, and fire clay from thecoal seam. After removing large non-coal fragments, water is addedto the raw coal to produce a 12 percent coal slurry to separate theremaining shale, fire clay, and other particles from the coal. Six 200hp classifying cyclone pumps transport the coal slurry from acommon sump to the two classifying cyclones which separate the

slurry into two types. The slurry containing smaller mesh particlesis discarded while the slurry containing larger mesh particles isdewatered and discharged as clean coal.

The Randolph preparation plant was selected for processoptimization due to numerous changes to the coal washing process.The six pumps used to transport slurry to the cyclones exceededsystem process requirements, which can lead to inefficient operation.Alternatives to increase the energy efficiency of the pumping systemwere identified and evaluated. This project focuses on one (Number5) of the six cyclone classifying pumps which is representative of allsix pumps. Only one pump was selected so that multiple systemoptimization techniques could be explored without excessive costs.

Project Team

In addition to the host company, the Showcase Demonstration project team involved several Motor Challengepartners including U.S. Electric Motors, GIW Industries, Inc. and the local electric utility. U.S. Electric Motors andGIW Industries, Inc. supplied the equipment and performed system modifications throughout the projectsimplementation period. Electric metering of the pumping system for the base case and alternative scenarioswas provided by the local electric utility. Other mechanical engineering services and hardware provided to thehost company were performed by The Benham Group.

Project Implementation - The Systems Approach

Project engineers realized the current system was

oversized, not operating at its best efficiency point, and hadnot received proper maintenance over the years. Todetermine potential improvement opportunities, theengineers applied the systems approach. The systemsapproach is a way to increase the efficiency of an electricmotor system by shifting the focus away from the individualelements and functions to total system performance. Byutilizing the systems approach, Peabody Holding was ableto determine an overall strategy for optimizing the No. 5cyclone pump.The strategy involved all three main elementsof the pumping system: the pump casing and impeller, themotor, and the V-belt dr ive.

The Old System

Under normal conditions, the pump runs at constant volumeand operates approximately 16 hours a day for 250 days ayear. The original pump system util ized a 10" x 10" casingequipped with a 32" diameter impeller designed to pumpan estimated 4,650 gallons per minute (gpm) at a head of114 feet. The pump was driven by a 200 hp, 1,750 rpmstandard efficiency motor through a conventional V-beltClassifying Cyclone Pump

CLASSIFYING

CYCLONES

DISTRIBUTOR

CLASSIFYINGSUMP

DISCHARGEPRESSURETRANSDUCER

PANAMETRICSPT-868 ULTRASONICFLOWMETER

SUCTIONPRESSURETRANSDUCER

CLASSIFYING CYCLONE PUMP

60f

t.

21f

t.6

in.

20f

t.

SIC:1211

Products: Clean coal

Location: Marissa, Illinois

Employees: 66

Showcase Team Leader: Ronald Cross

Company Philosophy: Peabody iscommitted to implementing an energyefficiency plan that is cost-effective andsupports voluntary actions to reducegreenhouse gases.


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drive. After performing system analyses, theteam determined that the original systemexceeded process requirements. Overall wire-to-water system efficiency was rated at lessthan 59 percent. Average volume flow wasestimated at an average of 3,612 gpm at a head

of 107 feet, less than the pumps most efficientoperating point. Overall energy consumption wasestimated at 513,766 kWh of electricity per year.

Alternatives Considered

Several alternatives were considered tooptimize the pump system. One option involvedslowing down the pump to reduce speed andlower energy consumption levels; however,initial calculations showed little energy savings from performing this task. Engineers also considered stagingthe six pumps, but this proved impractical. Another area explored was replacing the V-belt drive with a newertoothed-belt drive, rated at efficiency levels of 98 percent. After several tests, it was determined that the

toothed-belt drive did not significantly increase the efficiency of the pump system. In addition, toothed-beltdrives are less tolerant of contamination and are significantly more noisy than V-belt drives. The optimal solutionproved to be a combination of system modifications which include replacing the pumps motor with a moreefficient motor, downsizing the pump, and re-tensioning the V-belt.

The New System

The modified system uses a smaller pump with an 8" x 10" casing and a 32" diameter impeller with an outputthat more accurately matches system flow requirements. The original motor was replaced with a new premiumefficiency 200 hp, 1800 rpm motor rated at 96.5 percent efficiency. At the time of replacement, the team alsodetermined that the motor slide base should be replaced as a result of extreme corrosion. Maintenance of theV-belt drive, to prevent corrosion and set the proper tension, was also performed.

Results

Prior to system modifications, the pumping system operated at an average 58.7 percent wire-to-water efficiency.After the motor and slide base were replaced, efficiency levels increased to 60.4 percent. By re-tensioning theV-belt drive, efficiency increased by an additional 2.5 percentage points to 62.9 percent. The most significantefficiency increase occurred after the pump was downsized to match volume flow requirements. Efficiencyincreased another 10.7 percent to an average wire-to-water efficiency of 73.6 percent. Overall energy efficiencyas a result of the motor replacement, V-belt drive tensioning, and pump modifications increased by 14.9 percentagepoints from 58.7 percent to 73.6 percent efficiency.

Coal Slurry Pumping System

Why Oversized Pumps Decrease Performance

Many design engineers purposely oversize pumps, taking into account factors such as safety margins,potential corrosion build up, and the possibility of increased flow requirements in the future. This often leadsto throttling the system with a control valve because the pump delivers more flow than the system requires.The result is a pump that is not running at its Best Efficiency Point (BEP). Possible consequences of thisinclude noise and vibration, excessive bearing loads, cavitation, and excessive power consumption. Pumpsthat are being throttled and are operating far off their BEP should be considered for retrofit. Possible changesthat should be considered are retrofitting with a smaller pump, using an impeller with a smaller diameter, orslowing the operating speed of the pump. In many cases, these changes will not only save energy, but alsoincrease the reliability of the system.


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The reduction in annual energy consumption is estimated to be87,184 kWh of electricity, equivalent to approximately $5,231 incost savings. With a cost of $15,693, the project yielded a simplepayback of 3.3 years. In addition, the project resulted in lowermaintenance costs for replacement parts since the new pump issmaller.

Lessons Learned

Aside from the energy savings achieved by modifying the system,several lessons were learned during the project implementationprocess. The experiences gained may provide practicalinformation for other projects targeting energy efficiencyimprovements. The lessons learned include: (1) To ensure thatpump systems are performing at optimal levels, the volume flowrate should be calculated to determine the appropriate sizedpump, rather than automatically replacing old pump casings withnew pump casings of the same size when they wear out. By notonly replacing the pump casing but by changing the size of the

pump casing to more accurately match the required flow rate,operating costs can be reduced significantly; (2) High performancebelt drives can increase energy efficiency and reduce costs;however, routine maintenance of the V-belt drive rather thanreplacement of the drive with high performance belt drives mayyield higher savings. Also, high performance belt drives are noisy relative to V-belt drives; and (3) After a pumpcasing and impeller are replaced with smaller ones, the system requires less motor power than was neededprior to system modifications. A smaller motor may be sufficient to operate the system, and can reduce projectcosts.

Contact:

Motor Challenge Information

Clearinghouse (800) 862-2086

www.motor.doe.govPrinted with a renewable source ink on paper containing at

least 50% wastepaper, including 20% postconsumer waste

February 1997

ORNL/MC-CS

About Motor Challenge

The Motor Challenge is a joint effort by the U.S. Department of Energy (DOE), industry, motor systems equipmentmanufacturers and distributors, and other key stakeholders to put information about energy-efficient electric motorsystem technology in the hands of people who can use it.

Showcase Demonstration Projects target electric motor-driven system efficiency and productivity opportunities inspecific industrial applications. They show that efficiency potential can be realized in a cost-effective manner andencourage replication at other facilities.

DOE provided technical assistance and independent performance validation (IPV) of energy savings. A DOE-sponsored IPV team reviewed the test plan and provided assistance, as requested by the host site, on testingprocedures, instrumentation techniques, and data acquisition. The DOE team developed a detailed IPV Reportthoroughly documenting the project. The Report is available by calling the number listed below. DOE did notwitness the actual test data, and the conclusions in this case study are based solely on data provided by the hostsite and their partners.

For more information on becoming involved in the Motor Challenge or sponsoring a Showcase Demonstration, callthe Motor Challenge Information Clearinghouse at (800) 862-2086.

Net Cost to Implement Project $15,693

Annual Energy Cost Savings $5,231

Simply Payback (years) 3.3

Demand Savings (kW) 21.8

Energy Savings (kWh) 87,184

182,633 lbs

Carbon Equivalent 49,900 lbs

5,115 lbs

1,090 lbs

PM 42.4 lbsCO 21 lbs

Non-Methane Hydrocarbons 2.5 lbs

Performance Improvement Summary

CO2

SO2

NOx

Total Annual Emissions Reductions

Annual Energy and Cost Savings
http://www.motor.doe.gov/http://www.motor.doe.gov/


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ENEFITS

Saves $280,000 annually

Reduces annual energy consumption

by 3.2 million kWh

Reduces water consumption

Improves system performance

Reduces purchases of water

treatment chemicals

Yields a simple payback of

15 months

PPLICATIONS

Mill or river water pumping systems

rovide process-cooling water for

dustrial plants and can consumegnificant quantities of energy.

ptimizing aging and inefficient mill

r river water pumping systems can

educe energy consumption, water use,

nd chemical treatment of river water.

March 2003OFFICE OF INDUSTRIAL TECHNOLOGIES

ENERGY EFFICIENCY AND RENEWABLE ENERGY, U.S. DEPARTMENT OF ENE

GLASSBestPracticesProject Case Study


Millwater Pumping System Optimization Improves

Efficiency and Saves Energy at an Automotive Glass P

Summary

In 2001, Visteon Corporations automotive glass plant in Nashville, Tennessee,

renovated its millwater pumping system. Over time, technological advances hadimproved the plants manufacturing efficiency, which lowered demand for procescooling water. However, because of its size and configuration, the pumping systwas providing more water than necessary. The renovation project involved retrofithe systems large, aging pumps with smaller units fitted with Variable Speed Dr(VSDs) to more effectively match the systems output to the plants demand. Thcompleted project greatly improved the systems efficiency and reduced the planwater use, saving substantial amounts of energy and water treatment chemicalsaddition, the project improved plant safety by eliminating an electrical hazard onpump barge. The projects total cost was $350,000 and the total annual savingswere $280,000, yielding a simple payback of 15 months.

Plant Background

Visteon is an automotive parts manufacturer that was spun off from Ford MotorCorporation in 2000. With 81,000 employees and more than 130 technical,

The Barge Pumping System at Visteons Nashville Plant


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Project Implementation

The plant personnel decided to retrofit the millwater pumping system based on Tencarvas systemreview and recommendations. The project centered on replacing the existing 350-hp pumps with two250-hp pumps, each fitted with a VSD. The proposed system design called for one pump to operatecontinuously while the second one would be brought online in a trim capacity to maintain theappropriate clarifier tank levels. The project was implemented without interrupting the plants watersupply, so production was unaffected. Existing bypass piping was utilized to isolate each pump as itwas being replaced. In addition, the clarifier tank was filled with enough water to buffer the systemwhile the new pumps were activated.

manufacturing, sales, and service facilities in 23 countries, Visteon produces a wide range of

automotive components for manufacturers all over the world. The companys three main businesssegments are Dynamics and Energy Conversion; Comfort, Communication and Safety; andAutomotive Glass.

The Visteon Nashville glass plant opened in 1956 and has since undergone 10 expansions thathave doubled its floor space and production output. It is the worlds largest complete automotiveglassproduction plant with more than 2 million square feet of work and storage space. The plant produceswindshields, backlights, and door glass. The millwater pumping system is important because itprovides water for the process cooling applications. Prior to project completion, the plant was servedby three 350-horsepower (hp) centrifugal pumps mounted on a barge in the Cumberland River. Twoof the pumps were constantly operated in parallel to pump water from the river to a clarifier where

the water was chemically treated. The third pump was kept for back up use.

Project Overview

Working with Tencarva Machinery Company, plant personnel reviewed the pumping system inrelation to the plants process cooling water needs. The review team began by assessing of theplants water demand, which allowed Tencarva to determine the optimal size and type of pumpingsystem.

The existing pumps were installed in 1968 when the plants load was approximately 5,200 gallonsper minute (gpm). Since then, increases in manufacturing efficiency and reduced need for coolingwater by the compressed air system had significantly reduced the plants load. The assessmentindicated that under normal operating conditions, the plant could operate effectively with 3,125 gpm.

Although plant personnel knew that the flow rate of 5,200 gpm was excessive before the review, therate could not be adjusted because of the pump system design. The pumps had an on/off controlsystem and because one pumps output was insufficient, two pumps were required to operate atfull load. Running both pumps this way consumed excess energy. Furthermore, the excess waterwas passed through the clarifier before being returned to the river, which consumed more watertreatment chemicals than necessary.

The review also revealed that the pumping systems controls were antiquated and did not haveremote monitoring capability. Therefore, two powerhouse operators had to go to the barge twice aday to perform the required system checks manually. In addition, the pumps controls and electricalsubstation, located on the barge, created an electrocution hazard when the deck of the barge flooded.The barges deck gets flooded periodically when storms allow debris to get wedged in the wheelsthat allow the barge to rise and fall with the river level. The debris prevents the barge from rising,


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In addition to being smaller, the new pumps possess remote monitoring capability, whicheliminates the need for powerhouse operators to check the system manually. Finally, the pumpcontrols and the electrical substation that serves the barge were relocated on land to eliminatethe electrocution hazard.

Results

The Nashville plants pumping system project has yielded important energy savings and hasimproved the systems performance. Before project completion, the plant operated two of its three350-hp centrifugal pumps at full load, which moved 5,200 gpm. The VSDs are now able to varythe pumps output capacity to accurately match the plants load and provide better tank levelcontrol of the clarifier. With the new system in place, the systems flow rate averages 3,125 gpm,a 40% reduction. Because the plant is able to meet its load by operating one pump at a time,plant personnel alternate each pump to share the load equally, thus preventing excess wear of eitherpump. The reduced flow rate has saved 3.2 million kilowatt-hours (kWh) and $98,000 per year.

One of the Two New 250-HP VSD-Controlled Barge Pumps


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BestPractices is part of the Office ofIndustrial Technologies Industries of theFuture strategy, which helps the countrysmost energy-intensive industries improvetheir competitiveness. BestPracticesbrings together emerging technologiesand best energy-management practicesto help companies begin improving energyefficiency, environmental performance,and productivity right now.

BestPractices emphasizes plant systems,where significant efficiency improvementsand savings can be achieved. Industrygains easy access to near-term andlong-term solutions for improving theperformance of motor, steam, compressedair, and process heating systems. Inaddition, the Industrial Assessment Centersprovide comprehensive industrial energyevaluations to small- and medium-sizemanufacturers.

PROJECTPARTNERS

Visteon CorporationNashville, TN

Tencarva Machinery CompanyNashville, TN

FOR ADDITIONALINFORMATION,PLEASECONTACT:

OIT ClearinghousePhone: 800-862-2086Fax: [email protected]

Visit our home page atwww.oit.doe.gov

Please send any comments,questions, or suggestions [email protected]

Office of Industrial TechnologiesEnergy Efficiencyand Renewable EnergyU.S. Department of EnergyWashington, DC 20585-0121

DOE/GO-102003-1658March 2003

In addition to energy savings, the project has allowed the plant to reduce itspurchases of water treatment chemicals, saving $116,000 annually. The plantalso saves $66,000 per year by checking the pumping system remotely. Thisnew functionality precludes the need for the powerhouse operators from goingonto the barge to manually check the pumps. The total project savings are thus$280,000 per year and, with a total project cost of $350,000, the simple paybackis just 15 months. Also, plant safety was improved by the eliminating the electrical

hazard posed by the controls being located on the pump barge. Finally, the moreefficient utilization and reduced use of Cumberland River water is importantbecause policies under review by the Tennessee Valley Authority (TVA) indicatethat additional surcharges may be forthcoming for the use of TVA-controlledinland water.

Lessons Learned

Aging and improperly configured industrial pumping systems can waste energyand incur high maintenance or operating costs. As industrial plants evolve overtime and manufacturing processes become more efficient, demand requirementswill also shift. Recognizing and adjusting the output capacities of industrial motor

systems in response to changing demand patterns saves energy and improvesproductivity. In the case of the Nashville Glass Plant, replacing aging, fixed-output pumps with smaller units fitted with VSDs created an optimally sizedpumping system that can effectively vary output in response to demand. Suchreconfiguring leads to important savings in energy, maintenance, and watertreatment chemicals.

Industry of the FutureGlassIn April 1996, several organizations representing the glass industry signed a

compact with the Department of Energy (DOE) in an effort to encourage

technological innovations that will reduce energy consumption, pollution, and

production costs in the industry. The glass industry published a report entitled

Glass: A Clear Vision for a Bright Future, which articulated the industry's

vision of its future. This compact set the foundation for collaborative efforts

between the industry and the Federal government. Signed by both key industry

players and Department of Energy officials, it was a formal commitment to

align DOE's limited resources to meet the challenges identified in the vision.

OIT Glass Industry Team Leader: Elliot Levine 202-586-1476.

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