A Technique for Cryopumping Hydrogen

A Technique for Cryopumping Hydrogen PDF Author: Jack Grobman
Publisher:
ISBN:
Category : Catalysis
Languages : en
Pages : 32

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Book Description
Experimental tests performed in vacuo indicated that a chemical adsorption reaction can be used to facilitate the cryopumping of H with liquidN-cooled condensers. Cryopumping is accomplished by reacting H with O to form H2O, which will readily condense on a liquid-N-cooled surface. The reaction in vacuo was performed on a solid catalyst, which consisted of a bed of Pd-coated alumina pellets. Cryopumping was observed at pressures as low as about 0.4 micron of mercury. A laboratory cryopump consisting of 5.8 lb of catalyst and a liquid-N-cooled condenser achieved a pumping speed of about 570 l/sec at 1.0 micron of Hg. A laboratory model of a cryopump which could be used in an electric rocket test facility was studied. The experimental data obtained were used to estimate the size of the catalyst bed necessary to test a 50-kw electric thermal rocket with an H propellant flow rate of 0.00063 kg/sec (a pumping speed of 580,000 l/sec at an operating pressure of 10 microns of Hg. (Author).

A Technique for Cryopumping Hydrogen

A Technique for Cryopumping Hydrogen PDF Author: Jack Grobman
Publisher:
ISBN:
Category : Catalysis
Languages : en
Pages : 32

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Book Description
Experimental tests performed in vacuo indicated that a chemical adsorption reaction can be used to facilitate the cryopumping of H with liquidN-cooled condensers. Cryopumping is accomplished by reacting H with O to form H2O, which will readily condense on a liquid-N-cooled surface. The reaction in vacuo was performed on a solid catalyst, which consisted of a bed of Pd-coated alumina pellets. Cryopumping was observed at pressures as low as about 0.4 micron of mercury. A laboratory cryopump consisting of 5.8 lb of catalyst and a liquid-N-cooled condenser achieved a pumping speed of about 570 l/sec at 1.0 micron of Hg. A laboratory model of a cryopump which could be used in an electric rocket test facility was studied. The experimental data obtained were used to estimate the size of the catalyst bed necessary to test a 50-kw electric thermal rocket with an H propellant flow rate of 0.00063 kg/sec (a pumping speed of 580,000 l/sec at an operating pressure of 10 microns of Hg. (Author).

Cryopumping

Cryopumping PDF Author: René A. Haefer
Publisher: Oxford University Press, USA
ISBN:
Category : Literary Criticism
Languages : en
Pages : 464

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Book Description
This book covers the physical theory, practical techniques, and applications of cryopumping--the production of a vacuum through the use of low temperatures. The importance of this technique has increased greatly in recent years due to the proliferation of new uses and the demand in many vacuum procedures for ultraclean gas atmospheres, low final pressures, and high specific pumping speeds. The author reviews recent developments that have resulted in safer pumps that allow full automation and that are superior to conventional pumps in installation and operation costs.

Cryopumping by Three Arrays at Pressures of 10( -3) to 10( -8) Mm Hg

Cryopumping by Three Arrays at Pressures of 10( -3) to 10( -8) Mm Hg PDF Author: Carlisle B. Barnes (Jr.)
Publisher:
ISBN:
Category : Liquefied gases
Languages : en
Pages : 94

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Book Description
Three arrangements of surfaces cooled to 21.5 K were investigated theoretically and tested to determine condensing rates and resultant vacuum pumping performance of the arrays at pressures of 1/1000 to 10 to the -8 mm Hg. These are identified as unshielded, flat shielded, and angled fin arrays. Theoretical performance and experimental performances were correlated. Measurement of vacua below 1/10,000 mm Hg. were shown to be of uncertain accuracy.

Capture Pumping Technology

Capture Pumping Technology PDF Author: K. Welch
Publisher: Elsevier
ISBN: 9780444508829
Category : Science
Languages : en
Pages : 384

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Book Description
This is a practical textbook written for use by engineers, scientists and technicians. It is not intended to be a rigorous scientific treatment of the subject material, as this would fill several volumes. Rather, it introduces the reader to the fundamentals of the subject material, and provides sufficient references for an in-depth study of the subject by the interested technologist. The author has a lifetime teaching credential in the California Community College System. Also, he has taught technical courses with the American Vacuum Society for about 35 years. Students attending many of these classes have backgrounds varying from high-school graduates to Ph.D.s in technical disciplines. This is an extremely difficult class profile to teach. This book still endeavors to reach this same audience. Basic algebra is required to master most of the material. But, the calculus is used in derivation of some of the equations. The author risks use of the first person I, instead of the author, and you instead of the reader. Both are thought to be in poor taste when writing for publication in the scientific community. However, I am writing this book for you because the subject is exciting, and I enjoy teaching you, perhaps, something new. The book is written more in the vein of a one-on-one discussion with you, rather than the author lecturing to the reader. There are anecdotes, and examples of some failures and successes I have had over the last forty-five years in vacuum related activities, I'll try not to understate either. Lastly, there are a few equations which if memorised will help you as a vacuum technician. There are less than a dozen equations and half that many rules of thumb to memorize, which will be drawn on time an again in designing, operating and trouble-shooting any vacuum system.

NASA Technical Note

NASA Technical Note PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 414

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Book Description


Advances in Cryogenic Engineering

Advances in Cryogenic Engineering PDF Author: K.D. Timmerhaus
Publisher: Springer Science & Business Media
ISBN: 147570531X
Category : Science
Languages : en
Pages : 591

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Book Description
The 1961 Cryogenic Engineering Conference Committee is pleased to present the papers of the 1961 Cryogenic Engineering Conference. We are grateful to have had the University of Michigan at Ann Arbor, Michigan as our host for the seventh annual meeting of this group. The Conference Committee in presenting the papers oftbis Conference takes this opportunity to acknowledge the assistance of an Editorial Committee in the selection of papers for the program. Since over one hundred and twenty papers were submitted, their task of screening and evaluating the papers was a dif ficult one. The Committee guided by G. j. V an Wylen, who also served as chair man of the Conference Committee, included R. W. Arnett, B. W. Birmingham, D. B. Chelton, R. j. Corruccini, C. j. Guntner, M. j. Hiza, R. B. jacobs, A. J. Kidnay, R. H. Kropschot, j. Macinko, D. B. Mann, R. P. Mikesell, R. L. Powell, J. R. Purcell, R. P. Reed, R. j. Richards, A. F. Schmidt, R. B. Stewart, and K. A. Warren.

Vacuum Technology

Vacuum Technology PDF Author: A. Roth
Publisher: Elsevier
ISBN: 044459874X
Category : Technology & Engineering
Languages : en
Pages : 575

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Book Description
This third updated and enlarged edition includes about 350 new papers added to the previous list of references. The contents have been revised and updated in the areas of: Thermonuclear pumping; Throughput; Transmission probability; Electronic circuit simulation; Sorption on charcoal; Desorption from porous materials; Desorption from stainless steel, A1 alloys (outgassing rates); Ion bombardment (glow discharge) cleaning; Clay - type pumps; Turbomolecular pumps-improvements; Cryosorption; NEG (Nonevaporable getter) linear pumps; Standards for measurement of pumping speed (Recommended practice, test domes); Spinning rotor gauges; Quartz friction gauges; Increase of sensitivity of thermocouple gauges; Lubrication in vacuum; Calibration of diffusion leaks; Improvements in leak detection. Besides its role in educational activities, the book will also serve as a handbook for those working in this field, or in fields connected to Vacuum Technology.Comments from the press on the second edition:"A valuable reference work for undergraduate libraries...well organized and clearly written and strikes an appropriate balance between completeness and attention to fundamentals. The index and references are unusually complete. Recommended." (Choice) "Roth's new book contains a comprehensive collection of information on rarefied-gas flow, physical and chemical phenomena associated with vacuum technology, the production and measurement of high vacuum and sealing and leak-detection techniques. One finds a wealth of equations, numerical examples, tables, graphs and monographs. The book is more a handbook than a source book of latest developments. It is suitable for teaching, but the wealth of organized data should also make the book highly useful to engineers..." (Physics Today)

Proceedings of the Ninth International Cryogenic Engineering Conference, Kobe, Japan, 11-14 May 1982

Proceedings of the Ninth International Cryogenic Engineering Conference, Kobe, Japan, 11-14 May 1982 PDF Author: K. Yasukochi
Publisher: Butterworth-Heinemann
ISBN: 1483164098
Category : Technology & Engineering
Languages : en
Pages : 873

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Book Description
Proceedings of the Ninth International Cryogenic Engineering Conference, Kobe, Japan, 11-14 May 1982 contains the papers presented during the entirety of the conference. The overall focus is on the presentation of technical developments and new applications in the field of cryogenics. The topics covered during the conference include high speed magnetic levitation train, magnetic fusion energy and its cryogenic applications, and cooling effects in a vortex cooler. Superconductivity and fusion, digital applications of the Josephson effect, thermally activated stirling cryocooler, and large cryogenic systems of the energy doubler are discussed as well. Physicists, chemists, engineers, and researchers in the field of cryogenics will find the compendium very insightful.

Experimental Investigations of Solid Nitrogen Formed by Cryopumping

Experimental Investigations of Solid Nitrogen Formed by Cryopumping PDF Author: K. W. Rogers
Publisher:
ISBN:
Category : Nitrogen
Languages : en
Pages : 52

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Book Description


Conceptual Design Study of a Multipurpose Aerospace Test Facility

Conceptual Design Study of a Multipurpose Aerospace Test Facility PDF Author: George C. Marshall
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 82

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Book Description