Buttermilk Hydro

Chittendon Falls

Claytor Dam

Collins Bascule Dam

ESAC WORKS July 1985

Fiske Mill

1852 Fourneyron

Golden Pond Hydro

Hunts Pond

Jaffery FireProtection

Konkapot Creek

Lake May PeltonWheel Removal

Livermore Falls

Martinsville Hydro

OSV

Shaker Mill Dam

Silk Knitters- RonMacleod

South Village Dam

Sparhawk Mills

Tannery Pond

Tannery Rebuild

Turners FallsGenerator Rewind

Valatie Falls

Valley Paper

USEFUL ENGINEERING:

Air Admission toHydro Runners

The Banki WaterTurbine Mockmooreand Merryfield

Barrel StaveBearing Repair

Bishops Method-STABGM Program

Blade Pitting-Boving LTD 1930

Cavitation-AcceleratedResearch, AllisChalmers Research

Cavitation &Vibration of a

In order to allow for work on the turbine, being done in the dry, designers elevated turbine. A cylindrical pipe was attached to the discharge end of the turbine to convey thshear weight, of the cylinder of water, created a vacuum at the discharge end of the runnturbine is a direct function of the drop in pressure across it, the lower pressure, creatincreased the total drop.

<<<<<<< Note cylindrical draft tube.

Figure Three: Hercules turbine with cylindrical draft tube. The early American builders were not mathPrinciple.

In the early years, prior to the turn of the last century, effective thrust bearingweight of the turbine, turbine shaft, generator rotor and the hydraulic thrust on the runvitae) thrust bearings, most units were designed with horizontal shafts. This put the deawooden thrust bearing only had to support the hydraulic thrust. In order to turn the waterunner, into the vertically discharging cylinder, a 90 degree cast iron elbow was inserte



Vibration of aDraft Tube

Cavitation-Prevention &Reduction, AllisChalmers Research

Causes & Effects ofCavitation inHydraulic Turbines

Chain Turbine by:Nguyen Minh Duy

Chain TurbineMechanics-Discussions withDuy

Characteristics ofModern HydraulicTurbines-ChesterLarner

Comparative TestsOn ExperimentalDraft Tubes- C MAllen & I A Winter 1923

Design of anOvershot Waterwheel

(by Carl Weidner)

Design of Pelton

Buckets

Design of SmallWater Turbines forFarm and SmallCommunities

Design of therunner of a Kaplanturbine for smallhydroelectric powerplants: TimoFlaspöhler

Draft Tube Design

Draft Tubes ofHydro-ElectricStations by M. F.Gubin

Draft Tube Tests

Ejection intoTailraces ofHydropower Plants:S. M. Slisskii

Evolution ofHydraulic PrimeMovers-Byron McCoy

Fall Increaser-Henry Ford

Fall IncreaserHerschel VenturiT b

Figure Four: Two runner on a horizontal shaft. This configuration is theoretically balanced, with wooden, lignum vitae, bearings. The hydraulic thrust is also taken up by a wooden, lignum vitae, thrurunner is pushing against each other there is no resultant thrust. In practice, leaves and debris block

As turbine designers in the U.S. became more theoretical, it was noted that a seriouthe high discharge velocities exiting the cylindrical draft tube. By applying Bernouli’s cylinder, it was noted that one could recover the velocity head by slowing the water downexchanging the cylinder for a cone. As the water enters the small end of the cone, it slothe length of the cone. The velocity head is recovered and converted into vacuum head on

Figure Five: Example of a conical draft tube coupled to a horizontal shaft turbine with a cast iron

The problem is, if you create a cone with too large a 1/2 angle, the water becomes dtube. At the point of separation, you get a high velocity, cylindrical core, passing throlaboratories, including WPI’s Alden Hydraulic Research Laboratory, investigated separatioincluding the simple conical tube (these are also called diffusers).

If you were to take a conical draft tube and project its sides to the apex of the cocone) the angle between the sides is the draft angle If you were to measure the same ang



Tube

Fall IncreaserMoody EjectorTurbine

Fall IncreaserHydraulic JumpApron

Feasibility Studiesfor Small ScaleHydropowerAdditions, A GuideManual, US ArmyCORPS of Engineers

Flashboard Pins

Gatecase Design-Kovalev

Governor Theory forthe Plant Operator

Graphics of WaterWheels- William Fox

Hydraulic Motors-M. Bresse & F. A.Mahan 1869

Hydraulic Turbines-Robert LongDaugherty

Hydraulic Turbinesby Arnold Pfau

Hydraulic TurbinesGelpke & Van Cleve

Hydrokinetic Energyin Massachusetts-William D. B. Fay

Hydrostatic BeamAnalysis

Impulse Turbines by Ely Hutchinson

Interferencefitting a largerunner shaft

Kaplan Blade DesignNACA Air Foil-Report No. 460

Kaplan Blade DesignNACA Air Foil-Report No. 628

Kaplan Design-Kovalev

Kaplan Design MarkoKogovsek.xls

A Laboratory Studyto Improve theEfficiency ofCrossflow Turbines-N. Aziz & V. Desai

cone) the angle between the sides is the draft angle. If you were to measure the same angvertical axis, the angle is called a ½ angle. For design purposes, the ½ angle should notseparation of flow.

As the years went by, engineers developed larger and larger sites. In order to keep horizontal shaft, turbine manufacturers started adding more and more runners to the horizAs Kingsbury developed his tilting wedge bearing, it was possible to install the unit witvertical conical draft tube to slow the water down, required a tremendously deep excavativertical distance from the bottom of the conical draft tube to the discharge pit floor isdraft tube.)

Figure Six: Here are four runners on a common shaft. The rpm stays the same because the diamis increasing with the number of runners. The dead weight is still on the wooden, radial bearings and runners discharging at the ends of the tee stands. The down side is the length of the turbine pit and d

In order to save on excavation costs and effectively turn the water back into the tincorporated. Here, the water is initially slowed down in a conical draft tube. The end ohorizontal section conveys the water back to the tailrace. It is interesting that the earthe cross sectional area of the elbow draft tube expanding along the length of the tube. the water tries to bend around the sharp, inner bend, of the 90 degree section and separahigh speed, horizontal, jet bashing along the floor of the draft tube.



N. Aziz & V. Desai

MeggeringGenerators

Meggering Earth Resistance

Motors asGenerators forMicrohydro, NigelSmith

Operation &Maintenance ofHydro-Generators

Out Gassing ofCross Flow Turbines

Parallel Operationof TurbinesAnalysis

Pelton Design-Daugherty

Powerhouse Design-

Miniwatt Hydro

Powerhouse Design-Natick Dam

Power PlantInspection

Rake-Leonard

Rake-Newport News

Rack Design-Chicopee-OlavHotvedt

Rack Design- PHI-Bill Fay

Rack Design-PHI-Brian French

Rack Design-PHI-KenSmith

Rack Design-ASCE

Rack Design-Hydraulic Institueof Munich

Rack Design-FlowInduced Vibrations

Rigging a largegenerator

Selecting HydraulicReaction TurbinesBUREC

Shafts- Kovalev

Shaft Couplings

Snows ImprovedWater Wheel

G

Figure Seven: Various forms of elbow draft tubes

It can be shown that it is impossible to have separation of flow in an accelerating designers cleverly slowed the water down in the vertical, conical section. They then decrtube through the elbow! This caused the water to accelerate through the elbow and the wat

the horizontal section of the tube back to the tailrace. It is important with elbow draftsubmergence is created at no flow conditions between the crown of the draft tube exit and

I inspected a draft tube for a utility in Maine. They complained that the newly insturned out that the draft tube had not been designed to the correct vertical length. The of water by 22 inches. This allowed air to extend all the way back to the elbow and most recovered.

It is extremely important that the draft tube for a high specific speed Francis rundesigned to recover the velocity head exiting from the runner. For these units, 35% of thtube.

Now, let’s design a simple conical draft tube.



Governor

Standard forHydraulic Turbineand Generator ShaftCouplings and ShaftRunout Tolerances

Stoplog DesignCalculation

Stoplog StructureDesign Calculation

Stress Analysis ofHydraulic TurbineParts, BUREC- F.O.Ruud

Some Fluid FlowCharacteristics ofa Cross Flow TypeHydraulic Turbine-Durgin & Fay

Tenth Census of theUS, 1880, WaterPower of the US,Part I- ProfessorTrowbridge

Tenth Census of theUS, 1880, WaterPower of the US,Part II- ProfessorTrowbridge

Tests on a KaplanHydraulic Turbine

TheoreticalConditions Relatedto an Open ChannelFlow LinearTurbine- Ishida &

Service

Theory of Turbines-De Volson Wood

Treatise relativeto the Testing ofWater-Wheels andMachinery, JamesEmerson 1879

Turbine Water-WheelTests- RobertHorton

Turgo, A High SpeedImpulse Turbine-Paul Wilson

Vortices at Intakes

Water Hammer-Lorenzo Allievi-Text

Water Hammer-Lorenzo Allievi-Figures

FIGURE ONE: SIMPLE CONICAL DRAFT TUBE

From trigonometry:

Tan theta= rise/run= R0/(X+L)=RI/X

Where: L= length of the draft tube

RO= outlet radius (big end)

RI= inlet radius (small end)

theta= draft tube ½ angle

Solve for x:

X= RI/Tan theta

Or

(X + L)= R0/Tan theta

X= (R0/Tan theta)-L

Setting X =RI/Tan theta= (R0/Tan theta)-L

L= (R0/Tan theta)-(RI/Tan theta)

= (R0-RI)/Tan theta but R=D/2

= (D0-DI)/2Tan theta

DO= outlet diameter (big end)

DI= inlet diameter (small end)

Previously I said the ½ angle to prevent separation of flow in conical draft tubes



Water Hammer-ASMESymposium 1933

Water Hammer _Norman Gibson

Water Hammer-E.B.Strowger

WaterpowerEngineering-DanielWebster Mead

Water Wheel Design-Ken Smith

Weights

WHAMO

Wooden Penstocks

TRADE CATALOUGES:

Bradway Turbine (progressive gate)

C.P.Bradway Turbine

Brook Waterwheel

Charmilles Turbines

Christiana Machine(register gate)

Dayton Globe

Electric MachineryCompany (EM)

English Pelton

ESAC

Essex Turbines

GE WW Vert Gen

GE Springbed Brg

Gilkes Turbines

GilkesWaterpower

Head Gate Hoists-S. Morgan Smith

Holyoke Hercules

Hunt Cat 29 A&B

Hunt cylinder

J & W Jolly (cylinder gate)

Kingsbury Brg

Leffel Bulletin 38

Leffel Bulletin 54

Leffel Hoppes Unit

Leffel LaboratoryUnit

Previously I said the ½ angle to prevent separation of flow in conical draft tubes

Inserting 6 degrees into our equation yields:

L= 5*(Dexit-Dinlet)

This is a conservative equation for sizing conical draft tubes for small turbines that do not need

As an example, Celesty purchased two Leffel, 17A Samson turbines. These are equippedbridge tree with a lignum vitae thrust bearing is cast into the end of the draft tube. Thdraft tube is too short and the bridge tree disturbs the flow in the draft tube. We decidinstalled a 3/8 inch steel plate, conical draft tube. We used a Timken bearing, located othrust and weight.

From Leffel’s Bulletin 38 at 12 feet of head,

Q17A= 1394 cfm= 23 cfs

Industry practice is one meter per second velocity from the end of the draft tube o

For an incompressible fluid, the discharge area is:

Q= V * A or

Area= flow/velocity= Q/A

At 23 cfs, the area is:

A= 23 cfs/3 fps= 7.67 feet square

But:

A= phi* D*D/4 or:

D= (4*A/phi)^0.5

D= (4*7.67)/phi)^0.5

= 3 feet<<<<<<

We measured the discharge end of the runner. Remember to measure the inside diameteroutside diameter. The water flows out of the inside diameter.

The discharge diameter measured with a large caliper was 21.25 inches= 1.77 feet.

From our formula, L= 5*(Dexit-Dinlet):

L= 5*(3.00-1.77)= 6.15 feet or 74 inches.

And that’s what we made!!!!!!



LeffelMiscellaneous

Kingsbury CatalogC-1

Lombard Direct-Connected OilPressure GovernorsBulletin N0. 113October 1st, 1912

Lombard Governor

Lombard GovernorCompany Type TInstruction Book

Lombard Governorsfor Waterwheels andSteam Engines-1902

Lombard Water WheelGovernors Catalouge26

Michell Bearings

Pelton Wheel (1909)

Pelton Wheel (1925)

Ridgway PerfectionWater-Wheel

Rodney Hunt

Samson PamK

Smith Bulletin 110

Smith Power Tables

Smith Kaplan

Smith Power

Smith Pelton

Smith Develop

Smith Turbines:Bulletin 105

Swain Turbine

Trump HydraulicTurbines

Trump Turbines

Tyler Turbine

Vertical ShaftWater Wheel DrivenGenerators- GeneralElectric

Wellman SeaverMorgan

Westinghouse SmallVerticalWaterwheel-DrivenA-C Generators,July 1944

Here is Celesty's draft tube being rolled at the fabrication shop. It is morseries of progressively larger cones and butt weld them together. Mike Piesyk of Chicopee, Ma realized he could roll two axial shells and weld the longitudinal seAfter is was welded, he installed the turbine throat ring and flange to complete



y

Westinghouse WWGenerators

Woodward Governor

Links:Swiftriverhydro.com

damengineers.com

Smith AlternativeEnergy(www.smithtest.com)

Here Mike Piesyk and I are loading the completed draft tube into my trusty FTannery Pond site. Note the cylindrical throat and flange we designed to match ththe small step at the bottom of the throat. This step matches the size of the Saminside diameter of the step matches the inside diameter of the turbine skirt ringseamlessly out of the runner and into the draft tube.

Here is Celesty's little draft tube being lowered into the waterbox. The red draft tturbine. It is resting in the steel thimble that housed the Leroy Somers tube turbine.



Here we have leveled the two draft tubes. We set them on I-beams and installand the draft tube flange. We used a Starrett 12 inch, Master Precision Machinistten thousanths of an inch per foot to complete the leveling. We then poured the cCelesty's little draft tube is setting on the steel leveling I-beams. We have insthe powerhouse to keep the concrete in.



Here is the 17 A Samson turbine sitting on top of Celesty's draft tube readygrouted in between the I-beams. We made a stiff mix of concrete and sloped it up to slip into the turbine wicket gates.



Draft Tubes

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