Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Subcooled boiling heat transfer to R 12 in an annular vertical channel (1988)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 11 (1988), S. 320-327 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Detailed knowledge of the physical phenomena involved in subcooled boiling is of great importance for the design of liquid-cooled heat generating systems with high heat fluxes. Experimental heat transfer data were obtained for forced convective boiling of dichloro-difluoroethane (R 12). The flow is circulated upwards through a concentric annular vertical channel. The inner and outer diameters of the annulus are 0.016 m and 0.03 m respectively. The reduced pressures studied were 0.24 ≤ p/pcrit ≤ 0.8, inlet subcooling varied from 10 to 75 K and mass fluxes from 500 to 3000 kg/m2s, which corresponds to Re numbers from 30000 to 300000. The experiments, described in this study, demonstrate that liquid fluorocarbons show certain unusual boiling characteristics in the subcooled flow, such as hysteresis of the boiling curve. These characteristics are attributed to the properties of the fluid, mainly the Pr number and the very low surface tension. The pronounced boiling curve hysteresis can be explained by the fact that large nucleation sites may have been flooded prior to incipient boiling. A dimensionless regression formula is presented which predicts the onset of subcooled boiling as a function of reduced pressure (p/pcrit), Boiling-(Bo), Reynolds-(Re), and a modified Jacob number (Ja), over the whole range of parameters studied, with a good accuracy, including water data from literature.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270110142
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Separation of liquid from vapour upon pressure relief (1989)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 12 (1989), S. 54-63 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: When a chemical reactor is depressurized or pressure in a vessel, filled with saturated liquid, has to be decreased, generally both vapour and liquid flow out through the relief valve. Since chemical reactors are usually operated with toxic and explosive fluids, the discharged liquid which vaporizes on the ground around the vessel may reach dangerous concentrations, causing explosions or accidents with the poisonous gas. During a research project, some fundamentals were developed for the design of separation systems which separate liquid from vapour and store it in a receiver. The requirement for a separation efficiency of a least 80% is related to the condition that the separated liquid should flow back into the reactor still during the pressure relief phase. For safety reasons, both separation and re-storage are to be carried out without the supply of external energy. Theoretical and experimental investigations of pressure distribution within the piping to the relief valve and in an integrated separator show that re-storage of the separated liquid in the vessel can be achieved under certain flow conditions. Therefore, the separator must be integrated in the pipe at a certain height above the vessel, so that the hydrostatic pressure of the separated liquid, corresponding to the difference in height, is sufficient to lead it back through another pipe against the internal pressure of the vessel. First, several separators were tested with air-water mixtures. A swirl separator and a reversing separator have been developed to such an extent that they appear suitable for the set task. Experimental results with air-water mixtures and refrigerant R12 upon pressure relief show separation efficiencies of between 90 and 100% at low pressure drops within the whole operating range. As an alternative to separation outside the vessel, a rotary separator was also developed which is fixed to the outlet opening in the vessel. A centrifugal field is produced by the separator rotor and the heavier liquid is largely separated from the vapour so that only drops in the range 〈 100 μm flow together with the vapour towards the central standpipe. The outflowing vapour leaves the separator via 4 tangentially arranged nozzles, under critical conditions. The vapour flow momentum drives the separator rotor. The arrangement was developed and tested during various series of experiments, under conditions or pressure relief with refrigerant R12. So far, separation efficiencies between 60 and 95% have been achieved at stirring speeds of up to 2500 min-1.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270120110
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Aerosolabscheidung im Venturi-Wäscher mit mehrstufiger Eindüsung der Waschflüssigkeit im SelbstansaugbetriebVortrag von M. Lehner auf der GVC-Fachausschußsitzung „Mehrphasenströmungen“, 24. bis 26. März 1993 in Köln. (1993)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 65 (1993), S. 1355-1357 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330651112
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Experimentelle Untersuchung der Thermo- und Fluiddynamik in einem horizontalen Verdampferrohr mit EinspritzungVortrag von K. LAUFS anläßlich der GVC-Fachausschußsitzung „Wärme- und Stoffübertragung“, 7./8. März 1996 in Lahnstein. (1996)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 68 (1996), S. 1574-1578 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330681208
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Umrechnungsbeziehungen für die Übertragung des zweiphasigen Reibungsdruckverlustes von Frigen 12 auf WasserVorgetragen von L. Friedel auf dem Jahrestreffen der Verfahrens-Ingenieure, 17. bis 20. September 1974 in München. (1975)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 47 (1975), S. 293-293 
    Details
    ISSN: 0009-286X
    Keywords: Zweiphasen-Flüssigkeits/Dampf-Strömung ; Reibungsdruckverlust ; Dimensionsanalyse ; Modellgesetz ; angenäherte Ähnlichkeit ; unbeheizte Rohrströmung ; Reibungsdruckverlust-Diagramme ; Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330470706
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Blasenbildung und Wärmeübergang beim Sieden in freier und erzwungener Konvektion (1975)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 47 (1975), S. 737-748 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Der Wärme- und Stoffaustausch beim Sieden ist trotz einer großen Zahl experimenteller und theoretischer Untersuchungen noch nicht in allen Details seines physikalischen Ablaufes geklärt. Aus der Notwendigkeit, Verdampfer für die Energie- und Verfahrenstechnik auszulegen, ist eine Reihe halbempirischer Wärmeübergangsbeziehungen entstanden, die in den Modellvorstellungen ihres Ansatzes nicht nur aus Gründen des Rechenaufwandes, sondern auch mangels Detailkenntnisse von vereinfachten Annahmen ausgehen, müssen, aber durch Anpassung an Meßergebnisse trotzdem für die Praxis zum Großteil ausreichend genau sind. - Es werden die wichtigsten Phänomene des Wärme- und Stofftransportes bei der Verdampfung beschrieben und daraus einige Ansätze für die Berechnung der Wärmeübergangskoeffizienten erläutert. Behandelt wird das Sieden sowohl bei freier Konvektion als auch bei Zwangsströmung längs Heizflächen über den gesamten, in einem Dampferzeuger zu erwartenden Bereich vom Zustrom unterkühlter Flüssigkeit bis zur vollständigen Verdampfung.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330471802
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Tropfenmitriß und Flüssigkeitsverteilung bei Ringströmung von Gas/Flüssigkeits-Gemischen (1978)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 50 (1978), S. 554-555 
    Details
    ISSN: 0009-286X
    Keywords: Tropfenmassenstrom ; Entrainment ; Zweiphasenströmung ; Ringströmung ; Erhaltungssätze ; optische Meßtechnik ; Phasenverteilung ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330500718
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Experimental and analytical study of countercurrent flow limitation in vertical gas/liquid flows (1992)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 15 (1992), S. 51-62 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An experimental and analytical study of adiabatic countercurrent flow limitation (flooding) in single vertical ducts is reported. The experiments were carried out in a rectangular channel using saturated liquid and vapour of Refrigerant 12 (CCl2F2). The steady-state liquid delivery (flooding) curves as well as local pressure drop and void fraction distributions in the countercurrent flow were measured in a range of system pressures from p/pcrit = 0.16 to p/pcrit = 0.31, and for various total liquid injection rates and locations. The measured flooding curves j1 = f(jg) as well as pressure drop and void fraction during partial liquid delivery (j1 〈 j1in) were not affected either by the axial liquid feed location or by the excess liquid rate carried upwards by the vapour. Moreover, for given flow conditions during flooding pressure drop and void fraction were essentially the same at different axial positions. Radial void fraction distributions evaluated from optical fibre probe data indicate an annular-type flow pattern. Based on this experimental evidence, a mechanistic core/film flow model was developed for the calculation of flooding. The analytical results are compared with the present high pressure and with comparable atmospheric pressure experimental data, showing reasonable overall predictions not only of the flooding curves, but also of the pressure drop in countercurrent flow.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270150110
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Neue Gleichung zur Berechnung der Staubabscheidung im HochleistungsventuriwäscherVortrag auf dem Jahrestreffen der Verfahrens-Ingenieure, 27 bis 29. Sept. 1978 in Aachen. (1979)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 51 (1979), S. 235-235 
    Details
    ISSN: 0009-286X
    Keywords: Venturi-Wäscher ; Staubabscheidung ; Berechnungs-gleichung ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330510318
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Stand der thermohydraulischen Kenntnisse bei DruckentlastungsvorgängenVortrag auf dem Jahrestreffen der Verfahrens-Ingenieure, 1. bis 3. Okt. 1980 in Straßburg. (1981)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 53 (1981), S. 424-432 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Description / Table of Contents: The state of thermohydraulic understanding of pressure release phenomena. In calculating the depressurization, for example for the construction of safety valves, retardation of boiling, foaming-up due to flashing, phase separation, critical discharges as well as thermo- and fluid-dynamic coupling of different plant components play an important role. Sufficient knowledge of these physical phenomena only exists for water, within the context of nuclear-reactor-safety research. In this article, the state of the art with respect to the above fluid dynamic phenomena is discussed, including computer-programs which allow the prediction and analysis of the variation of pressure and fluid levels during pressure release: the treatment is also applicable to composite plant. In addition, the application and transfer of thermohydraulic data to chemical plants is illustrated.
    Notes: Bei der Berechnug der Druckentlastung, z. B. für die Auslegung von Sicherheitsventilen, spielen Siedeverzug, Aufschäumen durch Entspannungsverdampfung, Phasenseparation, kritisches Ausströmen sowie die thermo- und fluiddynamische Kopplung von Apparatekomponenten und -Gruppen eine Rolle. Kenntnisse über diese physikalischen Vorgänge sind in ausreichendem Maße nur für Wasser aus Untersuchungen zum Störfallverhalten von Kernkraftanlagen vorhanden. Es wird der Stand der Kenntniss über diese fluiddynamischen Vorgänge diskutiert, unter Einschluß von Rechenprogrammen, welche den zeitlichen Druck- und Füllstandsverlauf auch im Apparateverbund analysieren lassen. Wege zur Anwendung und Übertragung der thermohydraulischen Kenntnisse auf Chemieanlagen werden aufgezeigt.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330530607
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...