cp&e agitation systems 7 15

High Efficiency Hydrofoil Agitators

Presentation by

Chemical Plant & Engineering Pty Ltd Australia

Company Introduction

Chemical Plant and Engineering Pty Ltd (CPE) was formed in 1953 and has over 30 years of equipment supply history with many leading Mining companies.

Is an operating subsidiary of CEM International Pty Ltd and is a wholly owned Australian company.

Designs and manufactures process equipment for the wine, food, mineral processing, chemical, water and wastewater treatment industries.

Offers a complete engineering service starting from laboratory and pilot plant testing through to detail engineering design, manufacturing, and supervision of installation and commissioning.

CPE HAS MANUFACTURING FACILITIES IN BOTH AUSTRALIA AND CHINA

Company Introduction

CPE design / engineering philosophy is to provide the client with BEST SOLUTION to their problem at a cost effective price.

We CUSTOM design and engineer every product to the requirements of the client.

We do not supply standard off-the-shelf equipment for any application.

Laboratory testing is available to understand the rheology of non-Newtonian fluid required for agitator design

CPE provide ENGINEERED solutions for every project.

Local Sales & Support

Chemical Plant and Engineering Pty Ltd (CPE) is represented in the Americas by Crimar Industrial, based in Tucson, Arizona, with offices in Chile, Mexico, and China and sales agencies in Brazil and Canada

Crimar’s primary focus is on the mining and water treatment industries in the global market

Agitation Technology

The flow generated and the energy consumed by an agitator (just like a pump) are determined by published formulae that recognise the degree of work required to create process change.

The degree of work reflects the magnitude of the forces to be overcome and the environment in which this has to occur.

For a given process situation (tank size, physical and chemical nature of fluid etc) and a given set of physical conditions (diameter, speed etc) the effectiveness with which process change is accomplished is determined by the geometry of the device (impeller in this case).

Each Impeller is uniquely defined by two dimensionless groups– Nq which is the pumping number– Np which is the power number.


In order to make a comparison of flow between agitators the only item that changes in the formula below is Nq

Primary Pumping Capacity:

Q = Primary Pumping Capacity (m3/min)

Nq = Pumping Number

N = Shaft Speed (rpm)

D = Impeller Diameter (m)

n = Number of impellers

Q = Nq N D3 n


In order to make a comparison of power required between agitators, the only item that changes in the formula below is Np.

Absorbed Power:

Power = kW

Np = Power Number

N = Shaft Speed (rpm)

D = Impeller Diameter (m)

n = Number of impellers

ρ = Density (kg/m3)

fμ = Viscosity Factor

Power = Np (N/60)3 D5 ρ fμ n


An agitator impeller is defined by it’s Power Number, Np, and it’s primary Pumping Number, Nq.

The relationship between power number and pumping number defines the efficiency of an impeller.

These numbers are constant.


The flow generated is a measure of the extent to which the shape impacts the fluid ; for example blades that impact at 90o(S4) will exert more force on the fluid (and thus create more flow) than a flat disc which impacts the fluid at 0o and creates little or no flow.

Conversely the work required to overcome the resistance to flow created by the S4 is significant whereas the flat disc is able to move through the fluid relatively easily.

Older technology was focussed on ensuring sufficient flow was created to achieve process change without a lot of consideration for the energy being consumed.

Modern technology strives to achieve a combination of effective flow whilst consuming a lower amount of energy.

The RTF4 impeller has the best ratio of flow created per unit of energy input.


Agitation Technology Shift

PropellerFlat Blade

Turbine

(S4)

HydrofoilPitch Blade

Turbine(P4)

Technology Progression

Impeller Efficiency Curve

0

0.5

1

1.5

2

2.5

3

3.5

Rushton 6 Blade 90 Pitch Blade

Turbine

45 Pitch Blade

Turbine

Prochem Maxflo Philadelphia Denver

Equipment MIL

Chemineer HE3 Warman AF Lightnin A310 CPE RTF4

Pu

mp

ing

No

./P

ow

er

No

.

1st Generation Hydrofoils

2nd Generation Hydrofoil

Turbine Impellers

RTF4

Impeller Data

Manufacturer/Type Power Number Pumping Number

CPE RTF4 Hydrofoil 0.15 0.50

Lightnin’ A310 Hydrofoil 0.30 0.56

Ekato Hydrofoil 0.32 0.50

Chemineer HE-3 Hydrofoil 0.36 0.50

Warman AF Hydrofoil 0.37 0.58

Philadelphia Hydrofoil 0.40 0.50

45o Pitch Blade Turbine 1.37 0.68

90o Pitch Blade Turbine 3.50 0.74

Rushton 6 Blade Disc 5.00 0.82

High Efficiency RTF4 Hydrofoil

WHY IS IT BETTER?

The RTF4 Hydrofoil was developed to reduce power consumption by maximizing flow and minimizing turbulence (or shear).

It does this by transferring the available energy into pure axial flow without turbulence at the impeller

HOW DOES IT WORK? Increasing width Profiled Edge Blade twist The Arch

High Efficiency RTF4 Hydrofoil

WHY IS IT BETTER?

The RTF4 Hydrofoil is manufactured in dedicated tooling to ensure the shape profile is maintained

Unlike the first generation Hydrofoils the shape is not taken from commercially available components (i.e. line pipe) and made to suit…the shape is optimum and has been developed first in theory and then manufacturing tooling made.

Independent verification by CSIRO has validated the dimensionless groups (Np & Nq) that define this shape.

Benefits to Mineral Plant Processing Operators

Power Savings generated by implementation of a programme to retrofit second generation hydrofoil impeller technology.

Ability to increase tank flow if required to increase yield or to reduce scale accumulation (if applicable) without the need to change the drive train

Capacity expansion if required without the need for expensive modifications to tank and agitator mounts etc

Increase of drive train service factors resulting in lower loadings, longer operating life and reductions in downtime and maintenance.

Power Savings

An example of the potential benefit by replacing impellers with latest generation technology.

Design Agitator Flow = 150,000 gpm (568 m3/min)

P4 Pitch Blade

P4 Pitch Blade Lightnin A310CPE

RTF4

Impeller Diameter 150" 175" 150" 150"

Impeller Speed (rpm) 15.1 9.5 18.3 20.5

Power Consumption (Hp) 23.5 12.7 9.17 6.44

* Calculations based on SG = 1.0 and single impeller system.

Power Savings

In this example the annual benefits to plant operators would be as follows:

Annual savings based upon 98% utilisation @ A$

0.10/kWh


0.12/kWh


0.14/kWh

P4 Blade ( original configuration)

Nil (base case) Nil (base case) Nil (base case)

P4( modified configuration)

A$6868 A$8242 A$9615

Lightnin A310 A$9220 A$11064 A$12908

CPE RTF4 A$12967 A$15236 A$17776

Process Improvement

Agitator intensity is measured on a scale from 1 – 10 with scale 1 being very gentle agitation and scale 10 being rigorous turbulent flow agitation.

Application of technology that has been developed for certain applications over many years will generally suffice however in certain markets additional flow is required to address other process issues (like scale accumulation)

For example in a typical off bottom suspension application the design would call for a scale 3 degree of agitation whereas in an alumina application one might apply scale 4 or 5 to keep the internal tank velocities higher and thus limit potential for scale to adhere to the tank wall.

CPE analyses the entire application including related tank connections to ensure these are adequate and not sites for scale to commence to deposit.

Scale of Agitation Intensity

Unstable fillets on vessel

bottom

(agitation Intensity = 1)

Particles swept off vessel

bottom and uniformly

suspended for 13 of tankheight


Solids homogeneously

distributed for full tank

height


13 h

Mechanical Service Factors

Drive train selection involves the application of routine mechanical engineering data however the degree of safety applied between a theoretical requirement and actual installed capacity can sometimes vary.

In OEM applications we apply a service factor of between 1.5 and 2.5 ( the higher the service factor the longer the component life)

In applications where an RTF4 is retrofitted we can generally increase the process performance significantly without need to change motor or gearbox capacity and in some cases we increase the gearbox service factor thus increasing service life.

Current Market Activity

“ALL CPE RTF4 RETROFITS”

BARRICK GOLD – Granny Smith Mine (Australia) Completed

(Lightnin Agitators) 2008

LIHIR GOLD – Lihir Gold Mine (Papua New Guinea) Completed

(Lightnin Agitators)

RESOLUTE MINING – Carpentaria Gold (Australia) Completed

(Mixtec Agitators) 2007

NEWMONT MINING - Mill 5 Quarry (USA) Ordered

(Lightnin Agitator) 2009

NEWMONT MINING – Phoenix Gold Mine Waiting for (Hayward Gordon Agitators) approval to

proceed

Retrofits

Chemical Plant & Engineering, through use of its world leading RTF4 Hydrofoil, can offer retrofitting solutions for installations not meeting the process requirements. These limiting factors might be

Power Supply

Degree of Agitation

Detailed below are some case studies of industrial applications highlighting the actual situation and benefits delivered in a significant process plant situation.

Case StudyPoseidon GoldPlant Operator: Poseidon Gold

Big Bell MineDate: 1994Application: Gold Leaching

Process Data:Tank dimensions 13.6m diam x 14.1mOperating volume (m3) 2000Specific gravity solids 2.7Specific gravity liquid 1.0Specific gravity slurry 1.47% solids by weight 50Solids size (micron) 120

Process Limitation/Problem:Insufficient agitation due to agitator power consumption exceeding available motor power.

Case StudyPoseidon GoldApplication Gold leachInstalled Power 55 kWShaft RPM 13.8Impeller Type 2 x Lightnin A310

Impeller Diameter 4.88 metresPower Draw Excl. Drive Losses 29.6 kW (i)Agitation Scale 2 (ii)Pumping Capacity 1.8 x 106 litres/minute

Notes: (i) Original recommended speed was 16.7 RPM but insufficient drive power

was available to support this operating condition in the application(Power draw @ 16.7 RPM = 52.5 kW excluding drive losses).

(ii) Agitation Scale 2 will only provide off bottom suspension of solids.

Case StudyPoseidon Gold

Original Retrofit

Application Gold leach Gold leachInstalled Power 55 kW 55 kWShaft RPM 13.8 16.7

Impeller Type 2 x Lightnin A310 2 x CPE RTF4

Impeller Diameter 4.88 metres 5.334 metres

Power Draw 29.8 kW 41.1 kW

Agitation Scale 2 5

Pumping Capacity (m3/min) 1800 2500

Therefore the RTF4 impeller created 40% more pumping capacity for noincrease in installed power. Tank yield improved proportionately. Scale 5agitation intensity provides complete uniformity suitable for overflowdischarge.

Big Bell purchased one retrofit in 1994 as a trial and after successful commissioning purchased a further four units.

Case StudyLihir GoldPlant Operator: Lihir GoldDate: 2005Application: Gold Leaching

Process Data:

– Tank dimensions 13.7 m diam x 15.0 m– Operating volume (m3) 2182– Specific gravity solids 2.9– Specific gravity liquid 1.0– Specific gravity slurry 1.33– % solids by weight 40– Solids size (micron) 150

Process Limitation/Problem:

Agitator performance was satisfactory however excessive power consumption was noted.

Case StudyLihir Gold

Original Retrofit

Application Gold leach Gold leachInstalled Power 75 kW 75 kWShaft RPM 20 20Impeller Type 2 x Lightnin A310 2 x CPE RTF4

Impeller Diameter 1 x 4125 mm 2 x 4700 mm1 x 4775 mm

Agitation Scale 5 5Pumping Capacity (m3/min) 2006 2082

Power Draw (Actual) 75 kW 46.2 kW

The RTF4 impeller retrofit created savings of 38% on power usage whilst creating slightly more pumping capacity. Improved solids suspension also noted.


PROCESS OUTCOMES:

Good agitation was achieved in the tanks with minimal solids buildup in the bottom.

Power consumption was reduced considerably after the agitator retrofit.

Agitator life was increased due to minimal erosion due to solids buildup.

Gold Leach Agitators Installed at Lihir Gold

Case StudyBarrick Gold (Granny Smith)

Plant Operator: Barrick GoldGranny Smith Mine - Australia

Date: 2008Application: CIP

Process Data:Tank dimensions 11.1 m diam x 12.3mOperating volume (m3) 1190Specific gravity solids 2.8Specific gravity liquid 1.0Specific gravity slurry 1.47% solids by weight 50Solids size (micron) 140

Process Limitation/Problem:Some settling of solids and poor overall distribution of solids in suspension.


Original Retrofit

Application CIP CIPInstalled Power 45 kW 45 kWShaft RPM 25.6 19.7Impeller Type 1 X Lightnin A310 2 x CPE RTF4

1 x Lightnin A510

Impeller Diameter 2 x 3750 mm 1 x 4300 mm1 x 3810 mm

Power Draw 44.6 kW 18.3 kWAgitation Scale 5 5Pumping Capacity (m3/min) 1346 1337

Therefore the RTF4 impeller maintained the existing pumping capacity with a corresponding 59% reduction in power draw.

Case Study

Newmont Gold (Phoenix)Plant Operator: Newmont GoldDate: 2009Application: CIPProcess Requirement: Improved solids suspensionProcess Data:

Tank dimensions 11,125 mm x 13,198 mm

Operating volume m3 1223.6 Specific gravity solids 3.1Specific gravity liquid 1.0Specific gravity slurry 1.6% solids by weight 55Solids size (micron) max 208μm

Process Limitations:Existing installation indicates flow available from the agitator is grossly undersized for this solids loading and the flow being generated based upon the existing impeller characteristics represents about 60% of that necessary for the effective solids suspension for the solids data provided for the application.The required flow to provide a scale of 5 intensity is 2247 m3/min

Case Study

Newmont Gold (Phoenix)Application CIPInstalled Power 55kWShaft RPM 20 Impeller Type 2 x Hayward Gordon

Impeller Diameter 4115mmPower Draw 46.2 kW (inc 10% belt drive loss)

Agitation Scale 1 – 2 (i)Pumping Capacity 1393 m3/min

Notes: (i) The scale of 1 – 2 intensity available from the existing agitator will result in

ineffective suspension of the larger and / or heavier particles and they will accumulate on the tank bottom and eventually form a solid mass which when contacted by a rotating impeller blade generate significant stresses that may result in catastrophic failures that are being experienced,

Case Study

Newmont Gold (Phoenix)

Original Retrofit

Application CIP CIPInstalled Power 55kW 55kWShaft RPM 20rpm 20rpmImpeller Type 2 x Hayward Gordon 2 x CPE RTF4

Impeller Diameter 4115mm 4826mmPower Draw 46.2kW 52.7kWAgitation Scale 1 - 2 5

Pumping Capacity 1393m3/min 2247m3/min

Retrofit - Material of construction: Mild SteelExternal Lining: Natural Rubber

Case Study

Newmont Gold (Phoenix)

Comments on Retrofit

Guidelines for the retrofit set by the client required the utilization of the existing mechanical drive train.

Consequently the design was based upon the existing gearbox output shaft speed to ensure the unit operated within the available torque capacity of the gearbox.

Analysis shows that the RTF4 impeller was able to achieve the required flow for solids suspension (Scale 5) based upon the design data provided.

The consumed power of 52.7kW included a 10% allowance for losses in belt drive.

The selection was also made on the basis that the maximum recommended tip speed for rubber lined impellers in abrasive environments, as quoted by rubber manufacturers, was 5m/sec

The tip speed for the 4826mm impeller was 5m/sec at 20rpm.

Agitator Retrofit AnalysisMineral Processing Applications

Conclusions

Utilisation of the RTF4 impeller in mineral processing plants, either OE supply or as a retrofit, will reduce agitator operating costs.

Additional benefits will also result in the form of reduced scale build, better service life and reduced maintenance cost.

Chemical Plant is able to undertake an evaluation of refinery problem agitator applications and provide recommended courses of action if mineral processing plant operators have an interest in adoption of this technology.

CPE Local Representative

Crimar Industrial6720 E. Camino Principal, Tucson, AZ 85715(520) [email protected]

Santiago, Chile office: (56)2 431 5424 Regus CCU, Av. Vitacura 2939 Piso 10, Las Condes, Santiago, Chile [email protected]

Sonora, Mexico office: (662) 2-60-03-03 Blvd. Garcia Morales No.326, Col. El Llano, Hermosillo, Sonora [email protected]

Hebei, China office: (1590)321-6384 c/o Hauhua Zhongyi GFRP Co. Ltd., South Rd., West Belt Highway, Shijiazhuang, Hebei 050091 [email protected]

Brazil agent: InTec Inovação Aplicação Industrial Ltda. (55) 71-3289 3611 Av. Lui Tarquinio Pontes, 2,580, Lauro de Freitas, Bahia, Brasil [email protected]

Canada agent: SinFin Ltd., (416) 474-1588 31 Daffodil Avenue, Thornhill, Ontario,Canada

[email protected]

mailto:[email protected]

http://www.crimar.org/






Contact Us

CHEMICAL PLANT & ENGINEERING Pty Ltd

Phone + 61 393094822

Fax + 61 393090069

Mobile + 61418368881

Website www.cem-int.com.au/ourbusinesses/cpe/

Address P.O. Box 160 Broadmeadows VictoriaAustralia

http://www.cem-int.com.au/ourbusinesses/cpe/



cp&e agitation systems 7 15

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