11

Designing of submarine ballast-Designing of submarine ballast-drainage centrifugal pump with low drainage centrifugal pump with low

noise & vibration levelnoise & vibration level

Ballast-Drainage System

22

ContentContent

Piping & Instrumentation DiagramPiping & Instrumentation Diagram 44 Pump Unit PerformancePump Unit Performance 55 Impeller ProfileImpeller Profile 66 Impeller detail drawingImpeller detail drawing 77 Diffuser ProfileDiffuser Profile 88 General ArrangementGeneral Arrangement 99 Cross Sectional DrawingCross Sectional Drawing 1111 Dynamic Balancing of the Rotor AssemblyDynamic Balancing of the Rotor Assembly 1313 Researching PartResearching Part 1414 Balancing of Axial & Radial ForcesBalancing of Axial & Radial Forces 1717 Vibration & Noise ProtectionVibration & Noise Protection 1818 NPSHr ReductionNPSHr Reduction 1919

33

Content (continuation)Content (continuation)

Impeller Fabrication MethodImpeller Fabrication Method 2020 Impeller MachiningImpeller Machining 2121 Adapter for Impeller MachiningAdapter for Impeller Machining 2222 Manufacturing CostsManufacturing Costs 2323 ConclusionsConclusions 2424

44

Piping & Instrumentation DiagramPiping & Instrumentation Diagram

4 – Gate valve 5 – Ballast system piping 6 – Sea inlet 7 – Sluice valve 8 – Filter (mud box) 9 – Stop valves (switchgear)10 – Ballast pump11 – Drainage pump12 – Gate valve13 – Separator 14 – Hand pump15 – Protection cell16 – Drainage piping

1 – Suction filter2 – Mud box3 – Nonreturn valve

55

Pump Unit PerformancePump Unit Performance

Head = 30m Capacity = 300m3/h NPSHa = 5m NPSHr = 0,7m Ns = 2935 Nssimpeller = 13010 Rated Power = 45,93kW E-motor Power = 55kW Speed = 1500rpm Efficiency = 55%

66

Impeller ProfileImpeller Profile

Vanes profile

Velocity vector

diagram (outlet)

Velocity vector

diagram (inlet)

77

Impeller detail drawingImpeller detail drawing

Balancing holes

Space vanes

Back wear ring design

88

Diffuser ProfileDiffuser Profile

Back vanes

Inlet

Outlet

99

General ArrangementGeneral Arrangement

Gap between pump casing and mounting surface

1010

General ArrangementGeneral Arrangement

Elastomer between pump casing supports and

mounting surface

1111

Cross Sectional DrawingCross Sectional Drawing

Sleeve bearings

Axial-vortex stage

Balance drum

1212

Cross Sectional DrawingCross Sectional DrawingProvisions for vibration

measurement

Junction box

Cable glands

1313

Dynamic Balancing of the Rotor AssemblyDynamic Balancing of the Rotor Assembly

1414

Researching PartResearching Part

Inducer Axial-Vortex Stage

NPSHr & Noise level

1515

Researching PartResearching Part

Inducer• Amount of back flow is bigger• Noise level is higher• NPSHr is higher

Axial-Vortex Stage • Amount of back flow is less• Noise level is lower• NPSHr is lower

1616

Researching PartResearching Part

NPSHr & Noise level 1 – Impeller 2 – Inducer 3 – Axial-Vortex Stage

First acoustical positive suction head

Second acoustical positive suction head

Net positive suction head (Head drop by 3%)

Net positive suction head (Head drop by 25%)

1717

Balancing of Axial & Radial ForcesBalancing of Axial & Radial Forces

Axial loadAxial load• Back impeller wear ringBack impeller wear ring• Impeller balancing holesImpeller balancing holes• Balancing drumBalancing drum• Rotor weight reductionRotor weight reduction

Radial loadRadial load• Diffuser designDiffuser design

1818

Vibration & Noise ProtectionVibration & Noise Protection

Static balancing of rotate partsStatic balancing of rotate parts Dynamic balancing of the rotor assemblyDynamic balancing of the rotor assembly Sleeve bearingsSleeve bearings Low number of revolutionsLow number of revolutions Low NPSHrLow NPSHr Gap between pump casing and mounting Gap between pump casing and mounting

basebase Elastomer between casing supports and Elastomer between casing supports and

mounting basemounting base Flexible suction & discharge transition Flexible suction & discharge transition

pieces pieces

1919

NPSHr ReductionNPSHr Reduction

Using of Axial-Vortex StageUsing of Axial-Vortex Stage Reducing number of revolutionsReducing number of revolutions Increasing impeller eye squareIncreasing impeller eye square

2020

Impeller Fabrication MethodImpeller Fabrication Method

Casting Rotary machining (CNC unit) Turning

Turn broaching Turning Radial drilling

2121

Impeller MachiningImpeller Machining

Radial drilling

Rotary machining (CNC unit) Turn broaching

2222

Adapter for Impeller MachiningAdapter for Impeller Machining

2323

Manufacturing CostsManufacturing Costs

C1 – Material cost C2 – Buy-out cost C3 – Factory overheads C4 – Salary for involved employees

C1 = 43,7% C2 = 21,3%

C3 = 11,6%

C4 = 8,7%

C5 = 5,8%C6 = 3,6%

C7 = 2,3%

C8 = 3%

C5 – Equipment maintenance cost C6 – Shop overheads C7 – Social insurance for involved employees C8 – Out-of-process costs

2424

ConclusionsConclusions

Noise & Vibration Level ControlNoise & Vibration Level Control Weight & Overall Dimensions ControlWeight & Overall Dimensions Control High ReliabilityHigh Reliability Manufacturing Cost ReductionManufacturing Cost Reduction Easy Maintenance & RepairEasy Maintenance & Repair InterchangeabilityInterchangeability Environment ProtectionEnvironment Protection