Slurry Pump

Calgary Pump Symposium 2005Calgary Pump Symposium 2005Calgary Pump Symposium 2005Calgary Pump Symposium 2005

How to Specify the Operating Conditions for a Slurry Pump

J. A. Sharpe

President

J.A.S. Solutions Ltd.


Presentation Outline

• Background to the use of slurry pumps in oil sands processing

• Particle size and settling velocities

• Range of flows and pressure drops

• ANSI/HI Standard for Slurry Pumps

• Wear rates

• Conclusions


In the beginning was the dragline


Followed by the bucketwheel

Calgary Pump Symposium 2005Calgary Pump Symposium 2005Calgary Pump Symposium 2005Calgary Pump Symposium 200514 – 2.4 m3 buckets


And then miles of conveyors

Calgary Pump Symposium 2005Calgary Pump Symposium 2005Calgary Pump Symposium 2005Calgary Pump Symposium 2005Dumping onto a surge pile


Finally into a tumbler, where the oil sand meets hot water


Trucks and ShovelsIn the mid 1990s trucks and shovels replaced the draglines and bucketwheels

Additional capacity is readily available

Maintenance of haul roads

Flexible for blending ore composition to extraction

High unit cost ($/tonne_km)

Ability to switch units between ore and waste

Labour intensiveLower capital cost

ConcernsBenefits

Calgary Pump Symposium 2005Calgary Pump Symposium 2005Calgary Pump Symposium 2005Calgary Pump Symposium 2005Hitachi Shovel at Albian Sands Muskeg River Mine

Calgary Pump Symposium 2005Calgary Pump Symposium 2005Calgary Pump Symposium 2005Calgary Pump Symposium 2005Shovel Loading a 320 T truck

Calgary Pump Symposium 2005Calgary Pump Symposium 2005Calgary Pump Symposium 2005Calgary Pump Symposium 2005Double truck dump into the crusher feed hopper


Conveyor from Crusher to Surge Pile

Calgary Pump Symposium 2005Calgary Pump Symposium 2005Calgary Pump Symposium 2005Calgary Pump Symposium 2005Hydrotransport replaced tumblers - Slurry Preparation Towers

Calgary Pump Symposium 2005Calgary Pump Symposium 2005Calgary Pump Symposium 2005Calgary Pump Symposium 2005Conveyor Discharging Oil Sand into the Cyclofeeder


Hydrotransport feedPumpbox

Calgary Pump Symposium 2005Calgary Pump Symposium 2005Calgary Pump Symposium 2005Calgary Pump Symposium 2005Weir Hydrotransport Pumps at Syncrude’s North Mine

Calgary Pump Symposium 2005Calgary Pump Symposium 2005Calgary Pump Symposium 2005Calgary Pump Symposium 20053 km later the final destination, the primary separation cell


Particle Size and Settling Velocities

Deposition velocity in a pipeline is a function of:

D50 of the particles in the slurry

Pipe diameter

Particle size distribution

Slurry density


Typical Particle Size Distribution

0

10

20

30

40

50

60

70

80

90

100

1 10 100 1000 10000

Particle Size (microns)

Pe

rcen

t P

as

sin

g

Low

Average

High

Coarse High


Calculation of Deposition Velocity (based on D50 and dia.)

“Deposition-Limit Nomograms for Particles of VariousDensities in Pipeline Flow”, K.C. Wilson, Queen’s University,

Hydrotransport 6, September 1979


Saskatchewan Research Council Pipeflow ProgrammeInputs

FlowratePipe - internal diameter, wall roughness and slopeSlurry - specific gravity and temperatureSolids densityWater - density and viscosityD50 of coarse particles > 75 µFraction of fines < 75 µCarrier fluid viscosity

OutputsPipeline velocityDeposition velocityPressure gradientSolids volume fractionParameters outside the range of the database


Fines % vs Deposition Velocity(29" I.D. pipe, data from SRC Pipeflow 2003 Programme )

2

2.5

3

3.5

4

4.5

5

5.5

0 5 10 15 20 25 30

Fines %

De

po

sit

ion

Velo

cit

y

(m/s

) D50 = 400

D50 = 300

D50 = 250

D50 = 200D50 = 150


Slurry Density vs Deposition Velocity( 2 9 " id l ine, f ines f ract ion = 2 0 %, D 50 = 2 0 0 micron

SR C Pip ef low prog ramme)

1200

1250

1300

1350

1400

1450

1500

1550

1600

1650

4.60 4.65 4.70 4.75 4.80 4.85 4.90 4.95 5.00

D eposit ion V elocit y ( m/ s)

Reduction in density of 0.1 t/m3results in approximately 3%increase in deposition velocity


Range of Flows and Pressure Drops

Need to strike a balance between:

Exceeding the deposition velocity in the worst case scenario,which is usually the highest d50 with the lowest fines (MUST)

Minimizing the overall wear, which has to take into accountthe relative concentrations of the different ores and minimizing the overall pressure drop and therefore the powerrequired for the transportation. That is minimize velocity.

Maximizing the allowable turndown to achieve flexible operation

Optimizing the overall processing capability balanced against the capital and operating costs


38,130 m3/h

8,535 t/h oil sand5.3Coarse high

D50 400, 5% fines

176,750 m3/h

7,087 t/h oil sand4.4High

D50 250, 10% fines

604,295 m3/h

4,510 t/h oil sand2.8Average

D50 180, 15% fines

203,068 m3/h

3,220 t/h oil sand<2Low

D50 80, 30% fines

% of ore body

Flow rate at deposition velocity

Deposition velocity m/s

Ore Grade

29” id pipe, slurry density 1.55 t/m3


MUST provide sufficient pumping capacity to process thecoarse high grade 400 µ at a velocity of 5.3 m/s

Capital requirements are based on oil sand tonnage processed,therefore reduce rate on coarse high grade to 8,000 t/h bydecreasing the slurry density, maintaining the same velocity

Increase the slurry density on other grades to minimize flow requirements and increase available turndown

Increase tonnage processed to 8,000 t/h on all grades so thatoverall throughput is maximized and turndown increased


Resultant design basis, 8,000 t/h all grades, 29” id pipe

05.3

(8,130 m3/h)

1.52Coarse high

D50 400, 5% fines

125.0(7680 m3/h)

1.55High

D50 250, 10% fines

404.7

(7,230 m3/h)

1.58Average

D50 180, 15% fines

574.7

(7,230 m3/h)

1.58Low

D50 80, 30% fines

Turndown

%

Operating velocity m/s

Slurry density t/m3

Ore Grade


Pressure Drop in a Hydrotransport Pipeline

SG = 1.5k = 70 µPipe id =29”

TypicalDSRC = 180 µcPf = 3Fines 23%

CoarseDSRC = 400 µ cPf = 2Fines 15%

Section AB is upstream ofsection CD

“Performance of Sand Slurry Pipelines in the Oil Sands Industry”,R. Sean Sanders, Jason Schaan, Roxby Hughes and Clifton Shook,

Canadian Journal of Chemical Engineering, Vol. 82, Aug 2004


1.00.29

(29.6)

8130 (35,800)

5.3

Coarse high

0.720.225

(22.9)

7680 (33,800)

5.0

High

0.660.19

(19.4)

7230 (31,800)

4.7

Average

0.290.085

(8.7)

4620 (20,300)

3.0

Low turndown

Relative

Pressure Drop

Pressure drop kPa/m

(m slurry/km)

Flow rate m3/h (USgpm)

Velocity m/sOre grade

Calculated Pressure Drops


Coarse highgrade headadjusted to 40 m (131 ft) andother pointspro-rated


Pump Spacing Considerations

No.of pumps required = (static head + frictional head)head developed per pump

The greater the number of close coupled pumps, the higher the required pressure rating of the pump casing

The more spaced out the pumps are the lower the required pressure rating, but the higher the infrastructure costs


Pipeline profile

0

20

40

60

80

100

120

140

160

180

200

0 1 2 3 4 5 6 7 8 9 10

Distance from Plant (km)

Ele

vati

on

(m

)


Coarse highgrade headadjusted to 50 m (164 ft) andother pointspro-rated


ANSI/HI Standard for Slurry Pumps12.1-12.6-2005


Standard viscosity correction procedures can be used for homogeneous non-settling slurries provided the apparent viscosity is known


For heterogeneous slurries use Fig 12.20 and: Correct for solids sg = Cs =

((Ss-1)/1.65)0.65

Fines fraction = Cfp =(1 - fraction<75micron)2

Solids volumetric conc. = Ccv =(Cv%/15)

Modified Rh = Rh*Cs*Cfp*Ccv

Efficiency reduction follows head reduction

Reff = Rh





Wear Rates in Slurry Pumps

Influenced by:

Rotational speedDeveloped headParticle size distributionSlurry densityFlowrate

The first two items are controllable, the last three are process design issues


Suction side liner

Impeller

Shell

Main Wear Components – GIW TBC Slurry Pump

Hub liner

Calgary Pump Symposium 2005Calgary Pump Symposium 2005Calgary Pump Symposium 2005Calgary Pump Symposium 2005Worn Impeller from a Hydrotransport Pump


Relative Costs

Initial Capital compared with Cost of Wear Components

Pump + gearbox + couplings + motor + baseplate = 100 units

Cost Annual usage TotalSuction side liner 3 3 9Impeller 4.5 1.5 6.8Shell 20 1 20Hub liner 2 1.5 3

Spare parts cost per year 38.8

In approximately 21/2 years spare parts cost (excl. labour and downtime) = initial capital


Cost of Downtime

Oil sand rate = 8,000 t/hOre grade = 11% bitumenRecovery = 90%Bitumen density = 1 t/m3

Conversion from m3 to barrels = 6.29 Value of bitumen = Cdn$30/bbl

One hour’s production = 8000*0.11*0.9*6.29*30

= Cdn$149,450


A four foldincrease insolids sizeresults in20x casingwear rate

“Prediction of Slurry Pump Component Wear and Cost”, A. Sellgren,G. Addie, R. Visintainer and K. Pagalthivarthi. Paper presented at Western Dredging Association Conference, Houston, 2005

Effect of Solids Size on Casing Wear Rate


Effect of Pump Head on Liner Wear Rate

“Prediction of Slurry Pump Component Wear and Cost”, A. Sellgren,G. Addie, R. Visintainer and K. Pagalthivarthi. Paper presented at Western Dredging Association Conference, Houston, 2005

85% increasein pump headresults in3x increase in suction liner wear rate

D2 = impeller outside diameterD1 = impeller inside diameter

Calgary Pump Symposium 2005Calgary Pump Symposium 2005Calgary Pump Symposium 2005Calgary Pump Symposium 2005Parts Replacement as per the Sales Brochure

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Impeller Replacement on GIW Pump

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Slurry Pumps Installed in Series

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Cutaway View of a Weir 600 HTP Slurry Pump

Outer casing

Impeller

Throatbush

Volute Liner

Back liner


Exploded View of a Weir 600 HTP Slurry Pump


Weir 600 HTP Slurry Pump Installation


Parts Replacement on a Weir 600 HTP Slurry Pump


Conclusion

The steps required to successfully specify the operating conditions of a slurry pump are:

• Establish the particle size distribution of the ore body and split it out into suitable fractions, say 20, 60, 20

• Determine the settling velocities for the full range of slurries at the rates required in various pipe diameters

• Establish the most appropriate pipe diameter

• Adjust the flow conditions (density) to balance the conflicting requirements of settling velocity, wear rates and turndown


Conclusion (continued)

• Calculate the total pressure drop for the system using an appropriate programme

• Establish the “Service Class” for the slurry

• Specify the number of pumps required in series

• Select the pump based on: hydraulic fit anticipated wear rates time required to overhaul spare parts cost and lastly the initial capital cost


Acknowledgements

The assistance provided by the following companiesin the preparation of this presentation is greatly appreciated

Albian Sands Energy Inc.GIW Industries Ltd.Syncrude Canada Ltd.Weir Slurry Group Inc.

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Slurry Pump