Lempor Ejector Calculator Beta 1.1 [PDF]

Citation preview

INTRODUCTION by Richard Stuart



This spreadsheet originated with two live steam locomotive projects, commenced without knowledge sides of the world. Michael Guy in Toronto, Canada, and myself in Perth, Western Australia, both dec gauge Garratt locomotives. Both of us decided independently to fit our locomotives with a Lempor ex



The benefits of the Lempor exhaust had been widely described in the printed and electronic media, a the technology has been subsequently prepared by Michael on his web pages (appendix 1 Ref 1). B read Ing. L. D. Porta's 1974 paper (appendix 1 Ref 2) describing the theory of the Lempor ejector, an intimidated by the complexity of the mathematics used. However, a start had to be made somewhere background in fluid mechanics and experience as an oil and gas pipeline engineer, I ought to make th work. The result was a primitive combination of hand and spreadsheet based calculations, which gav Porta's paper and provided chimney throat and nozzle sizes for the Lempor exhaust design on my (R project.



The decision to develop the spreadsheet into a more user-friendly form was prompted by Michael, wh by a mutual friend, Russell Dunn. The ensuing cooperation between two live steam enthusiasts who this workbook. - Perth, Australia, October 2005



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INTRODUCTION by Michael Guy



Our intent has been to try to make L.D.Porta's important work on steam locomotive draughting more model engineer by removing the need to work complex mathematics to achieve a design. This workb to use and I believe that it is thanks to Richards clear analytical thinking. The user inputs are few and such as cylinder and wheel dimensions for the most part.



In using it myself, I found that even though an initial set of numbers looked really good, when I actual go back and tweak the sheet inputs as the reality of heights and clearances made themselves felt. Th Lempor calc sheet makes it very easy to see the effect of changing the diffuser geometry to suit your with Porta's instructions, post-installation track testing may require adjustments. The need to do this i method. To prove the sheet works, I built an ejector for my Romulus locomotive. Using the original no from 57mm water to 126mm, a huge improvement. As time allows I will try different nozzles to swap s draught for lower cylinder back-pressure. Go ahead, play with the numbers it can be great fun and the results will more than repay the effort. - Toronto, Canada, November 2005



IT IS IMPORTANT TO NOTE that this spreadsheet represents one implementation of Porta's theory that the implementation accurately reflects the great man's intent. The spirit in which the spreadshee summed up by Porta's introduction to his paper, in which he says:



"It is not a kitchen recipe guaranteeing good results without a good tuning up with measurem may try, providing that if success crowns his trial and error, the merit is to be credited to the t expects that the failure is not to be credited to the theory, but to the user." The spreadsheet will crunch the numbers but the user still has to interpret the results and design the



SPREADSHEET LAYOUT The workbook is split into the following sheets: - Introduction. - Lempor exhaust sizing calculation. (Use this sheet to design the ejector once you know the steam fl - Steam mass flow rate calculation. (Use this sheet to estimate the steam flow rate of your engine) - Appendix 1 of explanatory notes, cautions and hyperlinks. - Appendix 2, tables of locomotive data used in calculation verifications.



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CONDITIONS OF USE



Attention is drawn to the disclaimers printed on the Lempor and Steam Rate calculation work



It is considered that others in the live steam community will have the knowledge and experience to m improvements to the spreadsheet.  Such corrections and improvements are welcomed, provided that spreadsheet are clearly marked to identify changes and avoid confusion between versions, and that shared within the live steam model engineering community. Initial releases of the workbook will have passworded to prevent accidental changes. If you wish to try to make improvements or alter the math please contact us at the address below for an open version.



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The Lempor Ejector Calculator For the Model Engineer, Live Steamer and Student of the Second Generation Steam Locomotive Beta version 1.1 released November 2005



This workbook is copyright © Richard Stuart & Michael Guy, all rights reserved 2005



INTRODUCTION by Richard Stuart



This spreadsheet originated with two live steam locomotive projects, commenced without knowledge of each o sides of the world. Michael Guy in Toronto, Canada, and myself in Perth, Western Australia, both decided to b gauge Garratt locomotives. Both of us decided independently to fit our locomotives with a Lempor exhaust.



The benefits of the Lempor exhaust had been widely described in the printed and electronic media, and an exc the technology has been subsequently prepared by Michael on his web pages (appendix 1 Ref 1). Both Micha read Ing. L. D. Porta's 1974 paper (appendix 1 Ref 2) describing the theory of the Lempor ejector, and both of intimidated by the complexity of the mathematics used. However, a start had to be made somewhere, and I de background in fluid mechanics and experience as an oil and gas pipeline engineer, I ought to make the effort to work. The result was a primitive combination of hand and spreadsheet based calculations, which gave a soluti Porta's paper and provided chimney throat and nozzle sizes for the Lempor exhaust design on my (Richard St project.



The decision to develop the spreadsheet into a more user-friendly form was prompted by Michael, who was pu by a mutual friend, Russell Dunn. The ensuing cooperation between two live steam enthusiasts who have nev this workbook. - Perth, Australia, October 2005



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INTRODUCTION by Michael Guy



Our intent has been to try to make L.D.Porta's important work on steam locomotive draughting more accessibl model engineer by removing the need to work complex mathematics to achieve a design. This workbook was to use and I believe that it is thanks to Richards clear analytical thinking. The user inputs are few and are read such as cylinder and wheel dimensions for the most part.



In using it myself, I found that even though an initial set of numbers looked really good, when I actually drew th go back and tweak the sheet inputs as the reality of heights and clearances made themselves felt. The graphin Lempor calc sheet makes it very easy to see the effect of changing the diffuser geometry to suit your own loco with Porta's instructions, post-installation track testing may require adjustments. The need to do this in no way method. To prove the sheet works, I built an ejector for my Romulus locomotive. Using the original nozzle size, from 57mm water to 126mm, a huge improvement. As time allows I will try different nozzles to swap some of th draught for lower cylinder back-pressure. Go ahead, play with the numbers it can be great fun and the results will more than repay the effort. - Toronto, Canada, November 2005



IT IS IMPORTANT TO NOTE that this spreadsheet represents one implementation of Porta's theory and no gu that the implementation accurately reflects the great man's intent. The spirit in which the spreadsheet is made summed up by Porta's introduction to his paper, in which he says:



"It is not a kitchen recipe guaranteeing good results without a good tuning up with measurements. Ho may try, providing that if success crowns his trial and error, the merit is to be credited to the theory. If expects that the failure is not to be credited to the theory, but to the user." The spreadsheet will crunch the numbers but the user still has to interpret the results and design the ejector.



SPREADSHEET LAYOUT The workbook is split into the following sheets: - Introduction. - Lempor exhaust sizing calculation. (Use this sheet to design the ejector once you know the steam flow rate) - Steam mass flow rate calculation. (Use this sheet to estimate the steam flow rate of your engine) - Appendix 1 of explanatory notes, cautions and hyperlinks. - Appendix 2, tables of locomotive data used in calculation verifications.



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CONDITIONS OF USE Attention is drawn to the disclaimers printed on the Lempor and Steam Rate calculation worksheets.



It is considered that others in the live steam community will have the knowledge and experience to make corre improvements to the spreadsheet.  Such corrections and improvements are welcomed, provided that all revise spreadsheet are clearly marked to identify changes and avoid confusion between versions, and that all improv shared within the live steam model engineering community. Initial releases of the workbook will have protection passworded to prevent accidental changes. If you wish to try to make improvements or alter the math for your please contact us at the address below for an open version.



CONTACT INFORMATION



The authors hope that this workbook will be of interest and of use to the model engineering community worldw build or modify a model or indeed, a full-sized locomotive, we would be interested to hear about it and to see



Your feedback, photographs and suggestions for improvements or corrections are requested and welcomed a



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[email protected] ACKNOWLEDGEMENTS The authors would like to thank the following people: Nigel Day for kindly answering a number of emailed questions. Joe Dunham for MS Excel consulting to Michael Guy. Trevor Heath for kindly offering to host this work on his Livesteaming.com site



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Lempor Calculation Spreadsheet



Rev 1.1



Date: 1st November 2005



This workbook is copyright © Richard Stuart & Michael Guy, all rights reserved 2005. This spreadsheet is intended to provide a solution to Equation 9 of the following publication: "THEORY OF THE LEMPOR EJECTOR AS APPLIED TO PRODUCE DRAUGHT IN STEAM LOCOMOTIVES", L.D. PORTA, BUENOS AIRES, 1974 Disclaimers: No warranties or guarantees are given as to the correctness or appropriateness of the calculations in this spreadsheet. All input data, and all interpretations and applications of the results, are the responsibility of the user. By using this spreadsheet the user consents to take full responsibility for all costs and consequences arising directly and/or indirectly from any application of the results. Notes: Values in black to be input by user. Bold print indicates principal user input values. Values in red are calculated by spreadsheet Input Data column shows terms {ξb, etc} as used by Porta and units (m3/kg) as used in this workbook. PROJECT DATA Locomotive Description: Designer: Date:



7-1/4" gauge Romulus. R. Marsh November 20th 2005



INPUT DATA Exhaust System Parameters Gas mass / steam mass, L/D Coefficient, ξ Coefficient, ξb



PARAMETER



COMMENTS



2 2 (Appendix A3 and text of Porta's paper) 0.1 0.1 (Text of Porta's paper) 0.04 0.04 (Text of Porta's paper) 1.9 1.9 (Appendix A3 of Porta's paper)



Specific volume of exhaust steam, ν (m3/kg) Specific volume of gas, νb (m3/kg)



1.9 1.9 (Appendix A3 of Porta's paper) 1.9 (Appendix A3 of Porta's paper)



Specific volume of steam/gas mixture, ν1 (m3/kg)



1.9 4 (Appendix A1 of Porta's paper.) Note that this may not be 7 achievable in practice due to loading gauge constraints. 0.8 0.8 to 0.85 (Appendix A1 of Porta's paper.)



Chimney exit area/chimney throat area, Fs/F1 Diffuser efficiency, η Flow Parameters Design steam mass flow rate, D (kg/s)



0.0122 Steam flow through the exhaust system per second. Take the value from Steam Rate Sheet line 66. 875 Required smokebox vacuum 0.024304 Calculated - Steam mass flow rate x L/D



Design draught (Pa) Gas mass flow rate, L (kg/s)



The objective of the calculation is to determine the chimney throat area, F1 and Tuyere area, F, by trial and error solution of Equation 9. CALCULATED PARAMETERS Calculation Steps Trial value of chimney throat diameter (mm) Chimney throat area, F1 (m2) Chimney exit area, Fs, (m2) Ideal diffuser outlet area, F0, (m2) Equation term, λ D2v F1(Draught) Equation 9 denominator term Equation 9 denominator term Equation 9 denominator term Results Steam tuyere area, F (m2) Steam tuyere nozzle diameter (mm)



38 Vary this by trial and error to maximise Tuyere nozzle size 0.001134114947946 Calculate area from throat diameter 0.007938804635621 0.00243838446058 0.608163265306122 0.0002805750976 0.992350579452676 1.46544052224172 0.474999635943155



Multiply throat area by exit/throat ratio. From Porta's formula From Porta's formula Porta's equation 9 Porta's equation 9 Porta's equation 9 Porta's equation 9



0.000142920147414 Total area of the Lempor nozzles 6.745 Diameter of an individual Lempor nozzle - Assumes a 4 nozzle system.



Tuyere nozzle diameter (mm)



6.750



Value offset percentage Trial Value from cell B40



6.745 6.740 6.735 6.730 6.725 6.720 6.715 36.1



37.1



38.0



39.0



39.9



Chimney Throat Diameter (mm)



The above graph should exhibit a convex curve. Adjust the trial value chimney throat dia. until it does. The correct nozzle diameter is at the curve apex.



Tuyere Area Individual Nozzle Diameter



Imperial conversions 0.005512 lb/second 3.5 Inch H2O



1.496 inches



0.266 inches



This chart calculates values for the graph 95.0% 36.1 0.0010235 0.0071648 0.0022006 0.6081633 0.0002806 0.8955964 1.62E+00 0.5263154



97.5% 37.05 0.0010781 0.0075468 0.002318 0.6081633 0.0002806 0.9433533 1.54E+00 0.4996709



100.00% 38 0.00113411 0.0079388 0.00243838 0.60816327 0.00028058 0.99235058 1.47E+00 0.47499964



102.50% 38.95 0.00119153 0.00834071 0.00256183 0.60816327 0.00028058 1.04258833 1.39E+00 0.45211149



105.0% 39.9 0.00125 0.008753 0.002688 0.608163 0.000281 1.094067 1.33E+00 0.430839



0.00014 6.727



0.00014 6.741



0.00014 6.7448



0.00014 6.741



0.00014 6.729



The above graph should exhibit a convex curve. Adjust the trial value chimney throat dia. until it does. The correct nozzle diameter is at the curve apex.



Steam Rate Calculation Spreadsheet



Rev 1.1



Date: 1st November 2005



This workbook is copyright © Richard Stuart & Michael Guy, all rights reserved 2005. This spreadsheet is intended to provide a solution to Equation 61 of the following publication: "E. A. PHILLIPSON, 1936, "Steam Locomotive Design: Data and Formulae", Pub. Camden Miniature Steam Services, ISBN No. 0-9536523-9-4 Disclaimers: No warranties or guarantees are given as to the correctness or appropriateness of the calculations in this spreadsheet. All input data, and all interpretations and applications of the results, are the responsibility of the user. By using this spreadsheet the user consents to take full responsibility for all costs and consequences arising directly and/or indirectly from any application of the results. Notes: Values in black to be input by user Values in red are calculated by spreadsheet PROJECT DATA Locomotive Description Designer Date INPUT DATA Locomotive Geometry Cylinder diameter (mm) Piston stroke (mm) Wheel diameter (mm) Number of cylinders Operating Parameters Design speed (km/h) Design cut off (%) Cylinder Parameters Clearance volume (% cyl swept volume) Clearance volume, c (decimal of cyl swept volume) Volume swept to point of cut off, v (decimal of cyl swept volume) Volume from point of compression to end of stroke (% cyl swept volume) Volume from point of compression to end of stroke, x (decimal of cyl swept volume) Steam Parameters Boiler pressure (MPa gauge) Admission pressure (% boiler pressure) Admission pressure (MPa gauge) Admission pressure (MPa abs) Admission temperature (°C) Specific volume of steam at pressure of admission, Va (m3/kg)



Case 1 is based on SAR modified 25NC, case 2 on SAR 19D. Case 3 for 7-1/4" gauge Romulus miniature loco. Numerical Calculation Check Nov 16 2005



Case 1 610 711 1524 2



PARAMETER Case 2 Case 3 533 57.15 660 83.8 1372 165.1 2 2



COMMENTS Case 4 610 711 1524 2



70 35



70 35



12 75



70 35



10 0.1



10 0.1



10 0.1



10 0.1 Calculated - From % clearance volume



0.35



0.35



0.75



15



15



15



0.15



0.15



0.15



1.55 85 1.3175 1.4175 425 0.228821



1.38 85 1.173 1.273 425 0.2494



0.62 85 0.527 0.627 154 0.355



0.135



0.135



0.135



1.28



1.28



1.28



0.35 Calculated - From design cut off 15 Typical value estimated from published indicator diagram data: 15% 0.15 Calculated - From % compression volume



1.55 85 1.3175 1.4175 425 0.228821



Calculated - From % value input by user Calculated - add atmospheric pressure to gauge pressure Use superheater output temperature if so fitted User to input from steam tables at admission pressure and temperature



Temperature at initial pressure of compression (°C) 0.135 Range suggested by Phillipson: 19-20 psi (abs)



Initial pressure of compression (MPa abs) Specific volume of steam at initial pressure of compression, Vc (m3/kg)



CALCULATED PARAMETERS Calculation Steps Cylinder cross sectional area (mm2) Individual cylinder swept volume (mm3) Individual cylinder swept volume, V (m3) Distance travelled per wheel revolution (mm) Design speed (mm/min) Wheel revolutions, R (rpm) 120R {(v+c)V} / Va



1.28 User to input from steam tables at pressure and temperature of initial compression



COMMENTS 292246.66 223123 2565.2066 292246.66 Calculated from cylinder diameter 207787373 147261166 214964.31 207787373 Cross sectional area x stroke 0.2077874 0.1472612 0.000215 0.2077874 Convert units to cubic metres for convenience 4787.7872 4310.2651 518.67695 4787.7872 Equal to wheel circumference 1166667 1166667 200000 1166667 243.67555 270.67167 385.59647 243.67555 29241.066 32480.601 46271.576 29241.066 0.4086352 0.2657078 0.0005147 0.4086352



Convert km/hr to mm/min Divide design speed by distance travelled per revolution First term of Phillipson equation Second term of Phillipson equation



{(x+c)V} / Vc



0.0405835 0.0287619 4.199E-05 0.0405835 Third term of Phillipson equation Steam consumption per cylinder per hour 10762.225 7696.1436 21.87341 10762.225 Calculated by Phillipson Equation 61 (kg/hr) Results Total steam consumption per hour (kg/hr)



21524.45 15392.287 43.746821



21524.45 Multiply consumption per cylinder by number of cylinders



Steam consumption per minute (kg/min)



358.74084 256.53812 0.7291137 358.74084 Alternative units (kg/min)



Steam consumption per second (kg/s)



5.9790139 4.2756353 0.0121519 5.9790139 Units (kg/s) Enter this value in Lempor sheet cell B36



CONDITIONS OF USE Attention is drawn to the disclaimers printed on the Lempor and Steam Rate calculation



It is considered that others in the live steam community will have the knowledge and experience improvements to the spreadsheet.  Such corrections and improvements are welcomed, provide spreadsheet are clearly marked to identify changes and avoid confusion between versions, and shared within the live steam model engineering community. Initial releases of the sheet will hav passworded to ensure clean downloads. If you wish to try to make improvements or alter the m contact us at for an open version.



The Lempor Ejector Calculator



This workbook is copyright © Richard Stuart & Michael Guy, all rights reserved



APPENDIX 1 CONDITIONS OF USE



Attention is drawn to the disclaimers printed on the Lempor and Steam Rate calculation workshee



It is considered that others in the live steam community will have the knowledge and experience to make improvements to the spreadsheet.  Such corrections and improvements are welcomed, provided that all spreadsheet are clearly marked to identify changes and avoid confusion between versions, and that all im shared within the live steam model engineering community. Initial releases of the sheet will have protectio passworded to ensure clean downloads. If you wish to try to make improvements or alter the math for yo contact us at for an open version.



LEMPOR EXHAUST SIZING CALCULATION WORKSHEET The "Lempor Calculation" worksheet determines the following basic dimensions of the exhaust system: Chimney throat size. Blast nozzle size.



Note: Porta's equation expresses these sizes as areas. For the user's convenience, the worksheet converts areas to diameters, o system comprises a single chimney with four blast nozzles. For a multiple chimney system, the user will need to compute th nozzle diameters from the area data generated by the worksheet.



Attention is therefore brought to the work of J.J.G. Koopmans (Ref 3) which may provide a method of calculating multiple ch the values for a single chimney are known. The following input data is required: Mass flow rate of steam through the exhaust system. Required smokebox vacuum. A trial diameter for the gas mixing chamber and the small end of the chimney.



Note regarding Line 33: Chimney exit area/chimney throat area, Fs/F1. If room is available for a tall stack (e.g. on a narrow gauge locomotive) this value may exceed 4 to accommodate the recomm diffuser angle and the available height. Similarly, if headroom is short, the value may be less than 4. There are various methods of determining the mass flow rate of steam, including the following: Technical specifications of an existing locomotive with known parameters.



Experimental measurements on an existing locomotive. Calculations to determine the evaporation rate from the boiler. Steam consumption calculations based on the cylinder volume, wheel diameter, speed, assumed cut-off, etc.  This method capable of providing the volume of steam to be consumed.  The Steam Rate worksheet provides an approximate method of consumption rate using this philosophy. See below. The required smokebox vacuum can similarly be determined by various methods including the following:



Technical specification of an existing locomotive with known parameters. Experimental measurements on an existing locomotive. First principle calculations based on the required gas flow through the boiler. For full size locomotives, Wardale (Ref 4) and Chapelon (Ref 5) provide smokebox vacuum data for various locomotive type The smokebox vacuum for model engineering scale locomotives is much lower than full size. Experimental data from meas locomotives with conventional exhaust systems has been published by Michael Guy (Ref 6). 735 Pa may be used as a start



STEAM RATE CALCULATION WORKSHEET The "steam rate calculation worksheet" determines the steam flow rate per second through the exhaust system. The worksheet uses a method published by E. A. Phillipson (Ref 7) that requires the user to input the following information:



The engine geometry. The locomotives cylinder bore and stroke, wheel diameter and the number of cylinders used. Assum diameter. The operating parameters. The maximum speed of the locomotive and the designed maximum cut-off. The cylinder parameters section allows "tweaking" clearance volume etc to suit specific designs. The steam parameters section accepts boiler and cylinder admission pressures and temperature.



Note: The specific volume of steam is required in two places. These values can be obtained from steam tables or via the web, see The admission temperature should take into account the superheater if one is fitted.



Caution: Engine speed, valve-gear cut-off and steam "specific volume" input numbers make a real difference to the sheet output stea If the "Lempor calculation sheet" results are to be meaningful, these inputs must be realistic and accurate.



Note: The detail design of the components for an actual Lempor Ejector installation requires several dimensions not calculated by mathematical explanation of the ejector and the additional dimensions, written to assist the Live Steam enthusiast and Mode by Michael Guy and is available on the web (Ref 8).



REFERENCES & HYPERLINKS Ref 1/ Michael's Locomotive Pages: "Index page". Ref 2/ Ing. L. D. Porta's technical paper describing his Lempor Ejector Ref 3/ J.J.G. Koopmans "A Theory for the Design of Multiple Exhausts for Steam Locomotives" Ref 4/ "The Red Devil and Other Tales from the Age of Steam" D. Wardale, Pub. By Author, ISBN # 0-9529998-0-3



Ref 5/ "La Locomotive A Vapeur" Andre Chapelon, Camden Miniature Steam Services, ISBN # 0-9536523-0-0 Ref 6/ Michael's Locomotive Pages: "Vacuum Test Page". Ref 7/ "Steam Locomotive Design: Data and Formulae", E.A. Phillipson, Camden Miniature Steam Services, ISBN # 0-953652 Ref 8/ Michael's Locomotive Pages: "A Lempor Exhaust Ejector for the Garratt". OTHER LINKS Camden Miniature Steam Services The Ultimate Steam Page Martyn Bane's Steam & Travel Pages: "Modern and Modernised Steam Locos"



Useful Tools The authors of this worksheet have no connection with the following companies but have found these pages to be helpful. EngNet Tips and Tools page EngNet Metric Conversion Calculator Selection page ChemicaLogic's SteamTab Companion - a free downloadable Steam Table Calculator



of the freely please



This workbook is copyright © Richard Stuart & Michael Guy, all rights reserved 2005. Locomotive Data Source of data



SAR Modified 25NC



SAR Modified 19D



Model Locomotive Data



D Wardale, The Red Devil and Other Tales from the Age of Steam, Tables 26 & 27



D Wardale, The Red Devil and Other Tales from the Age of Steam, Tables 19 & 20



Comparison between asdesigned draft and Lempor-modified draft from track tests.



Steam flow rate through blast nozzle (kg/hr)



23,150



13050



Stack type



Steam flow rate through blast nozzle (kg/s)



6.431



3.625



Chimney Choke



Total chimney choke area, F1, cm2



2,798



1638



Chimney exit



Total chimney choke area, F1, m2



0.2798



0.1638



Total chimney exit area, Fs, cm2



6,196



4346



Total chimney exit area, Fs, m2 Fs/F1



0.620



0.4346



2.214



2.653



Track Test Results



Total blast nozzle tip area, F, cm2



302.5



176.6



Maximum Draft at 12-14 km/hr



Total blast nozzle tip area, F, m2



0.03025



0.01766



4865



5030



0.2743



0.1486



Design smokebox vacuum, Pa



Lempor Calculator Output Total chimney choke area, F1, m2 Discrepancy, % Total blast nozzle tip area, F, m2 Discrepancy, %



-1.97



-9.28



0.0297



0.01688



-1.82



-4.42



A Note regarding these results. Separate work was done to check the steam flow output against David Wardale's results. The steam flow output given by the steam rate sheet cannot be used directly because about 17.5% of the steam generated by the 25NC was tapped off for the feedwater heater and GPCS. This means that the steam flow output should be about 7.8kg/s to match Wardale's 6.43kg/s through the blast nozzles.



Mixing chamber or petticoat Blast nozzle type



% Change Blast pipe backpressure



R. Marsh Romulus Case 1



Modified Romulus Case 2



Modified Romulus Case 3



Existing Locomotive believed true to original design.



With Lempor Ejector as With same ejector calculated by the chimney but original sized spreadsheet without tuning. single hole blast nozzle.



Straight



10 degree taper Lempor Ejector with mixing chamber.



10 degree taper Lempor Ejector with mixing chamber.



Non



38mm



38mm



73mm



102mm



102mm



Non



38mm x 76mm



38mm x 76mm



Single hole 3/8"



4-hole diverging @ 9deg. 1/4" diameter holes.



Single hole 3/8"



57mm water



51mm water



127mm water -11%



Not measured, assumed to be similar to case 3.



122%



Lower than case 3, but not Above manometer range quantified during testing. of 178mm water.



A web page documenting these track test results is here.