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The Ultimate Steam Page

The Ultimate Steam Page

Uploaded February 25, 2000
page updated March 14, 2009

The Lempor Theory

This page provides an on-line version of Ing. L. D. Porta's technical paper describing his Lempor Ejector, written in 1974.. The Lempor Ejector is the most efficient exhaust system for steam locomotives developed so far.

Theory of the Lempor Ejector
as Applied to Produce Draught
in Steam Locomotives

by Ing. Livio Dante Porta


Introductory note by the author
Theory of the Lempor Ejector
Appendix A1. The Equivalent Ideal Diffuser
Appendix A2. The Kylpor Ejector
Appendix A3. Complementary Notes
Appendix A4. Specific Volumes of Steam, Gas, and Steam-Gas Mixture

Corrections to Lempor Theory (added January 2, 2006)

Jos Koopmans supplied the following corrections to the Lempor Theory. These may be typographical errors in transposing the theory from paper to electronic media or they may be errors in the original theory.

1. Fig.1 has D1, W1 near the orifice, should be D , W
2. In the list of definitions: W should be steam velocity at tuyere exit plane
3. At the bottom of the same page the division should not be by 2(L+D) but by (L+D)
4. Equation 2 carries a loose subscript 1 just before the square parentheses, remove
5. Next page has a sentence: "The optimal Fo that..." This should be Fb since the next differentiation is to Fb.

Note- as time allows, I will make these changes in the Lempor Theory as hosted on these pages.

An Adobe PDF version of the Lempor Theory may be downloaded here.

Michael Guy has provided a Microsoft Excel spreadsheet for designing a Lempor exhaust system here:

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