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Encyclopedia > Oxyhydrogen
"Knallgas" redirects here. For bacteria which oxidize hydrogen, see Knallgas-bacteria.

Contents

Oxyhydrogen is a mixture of hydrogen and oxygen gases, typically in a 2:1 atomic ratio, the same proportion as water.[1] This gaseous mixture is widely used for torches for the processing of refractory materials. This article is about the chemistry of hydrogen. ... This article is about the chemical element and its most stable form, or dioxygen. ...


Properties

Oxyhydrogen will combust when brought to its autoignition temperature. For a stoichiometric mixture at normal atmospheric pressure, autoignition occurs at about 570 °C (1065 °F).[2] The minimum energy required to ignite such a mixture with a spark is about 0.02 millijoules.[2] At normal temperature and pressure, oxyhydrogen can burn when it is between about 4% and 94% hydrogen by volume.[2] This article does not cite its references or sources. ... The autoignition temperature, or the ignition temperature of a substance is the lowest temperature at which a chemical will spontaneously ignite in a normal atmosphere, without an external source of ignition, such as a flame or spark. ... In chemistry, stoichiometry is the study of the combination of elements in chemical reactions. ... Atmospheric pressure is the pressure at any given point in the Earths atmosphere. ...


When ignited, the gas mixture converts to water vapor and releases energy, which sustains the reaction: 241.8 kJ of energy (LHV) for every mole of H2 burned. The amount of heat energy released is independent of the mode of combustion, but the temperature of the flame varies.[1] The maximum temperature of about 2800 °C is achieved with a pure stoichiometric mixture, about 700 degrees hotter than a hydrogen flame in air.[3][4][5] When either of the gases is mixed in excess of this ratio, or when mixed with an inert gas like nitrogen, the heat must spread throughout a greater quantity of matter and the temperature will be lower.[1] Water vapor or water vapour (see spelling differences), also aqueous vapor, is the gas phase of water. ... It has been suggested that this article or section be merged with Heating value. ... KJ or kJ is an acronym that could be referring to: KJ is the model code of the Jeep Liberty kilojoule (kJ), an SI unit of energy equal to 103 joules British Mediterranean Airways IATA airline designator Kaisertreue Jugend, a German monarchist organization Kevin Johnson nickname, former NBA player karaoke... The lower heating value (also known as net calorific value) of a fuel is defined as the amount of heat released by combusting a specified quantity (initially at 25°C) and returning the temperature of the combustion products to 150°C. The lower heating value assumes the latent heat of... Look up mole in Wiktionary, the free dictionary. ... This article is about the chemistry of hydrogen. ... In chemistry, stoichiometry is the study of the combination of elements in chemical reactions. ... An inert gas is any gas that is not reactive under normal circumstances. ...


Production

A pure stoichiometric mixture is most easily obtained by water electrolysis, which uses an electric current to dissociate the water molecules: Hoffman voltameter used to electrolyze water. ... This box:      Electric current is the flow (movement) of electric charge. ...

electrolysis: 2 H2O → 2 H2 + O2
combustion: 2 H2 + O2 → 2 H2O

The energy required to generate the oxyhydrogen always exceeds the energy released by combusting it. (See Electrolysis of water:Efficiency). Hoffman voltameter used to electrolyze water. ...


Applications

Limelights used an oxyhydrogen flame as a high-temperature heat source
Limelights used an oxyhydrogen flame as a high-temperature heat source

Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... This article does not cite any references or sources. ...

Historic uses

Many forms of oxyhydrogen lamps have been described, such as the limelight, which used an oxyhydrogen flame to heat a piece of lime to white hot incandescence.[6] Because of the explosiveness of the oxyhydrogen, limelights have been replaced by electric lighting. Look up Lamp in Wiktionary, the free dictionary. ... This article does not cite any references or sources. ... Lime has several meanings: Look up Lime in Wiktionary, the free dictionary Lime (mineral) - a group of calcium compounds and minerals in which they predominate, including: Limestone Agricultural lime - a mineral soil additive Calcium oxide (also quicklime) - a chemical compound Calcium hydroxide (also slaked lime) - a chemical compound Lime (fruit... As the temperature decreases, the peak of the black body radiation curve moves to lower intensities and longer wavelengths. ... Molten glassy material glows orange with incandescence in a vitrification experiment. ... Most of the industrialized world is lit by electric lights, which are used both at night and to provide additional light during the daytime. ...


It was much used in platinum works, as platinum could be melted (at a temperature of 1768.3 °C) only in an oxyhydrogen flame, or an electric furnace (which is now used instead). General Name, Symbol, Number platinum, Pt, 78 Chemical series transition metals Group, Period, Block 10, 6, d Appearance grayish white Standard atomic weight 195. ... A furnace is a device for heating air or any other fluid. ...


Oxyhydrogen torch

An oxyhydrogen flame
An oxyhydrogen flame

An oxyhydrogen torch is an oxy-gas torch, which burns hydrogen (the fuel) with oxygen (the oxidiser). It is used for cutting and welding metals, glass, and thermoplastics.[6] An oxyhydrogen torch is used in the glass industry for "fire polishing"; slightly melting the surface of glass to remove scratches and dullness. “Oxyacetylene” redirects here. ... For other uses, see Fuel (disambiguation). ... An oxidizing agent is a substance that oxidizes another substance in electrochemistry or redox chemical reactions in general. ... This article is about metallic materials. ... This article is about the material. ... For other uses, see Plastic (disambiguation). ...


The oxyhydrogen flame begins a short distance from the torch tip; if the distance is great enough the torch tip can remain relatively cool.[7]


Water torch

A bubbler apparatus used to mitigate potential flashback.
A bubbler apparatus used to mitigate potential flashback.[8]

A water torch is a kind of oxyhydrogen torch that is fed by oxygen and hydrogen generated on demand by water electrolysis. The device avoids the need for bottled oxygen and hydrogen, and requires electricity. Water torches must be designed to mitigate flashback by strengthening the electrolytic chamber. Use of an intermediary water bubbler eliminates potential electrolyzer damage from flashback, with a dry flashback arrestor being ineffective due to flame velocity. The bubbler is connected directly in series with the output gas. A water bubbler is sometimes referred to as a wet flashback arrestor, and effectively captures any remaining electrolyte in the output gas. Suitable electrolytes include sodium or potassium hydroxide, and other salts that ionize well.[7] Also "the electrolyzer system must be of high enough pressure to keep the gas velocity at the nozzle above the combustion velocity of the flame, or the system will backfire".[7] For images of water torch equipment see these links: [1] [2] [3][4][5][6][7][8]. Hoffman voltameter used to electrolyze water. ... A flashback Arrestor is a device most commonly used in Oxy-fuel welding to stop flame from burning back up into the equipment and causing damage or explosions. ... An electrolyte is any substance containing free ions that behaves as an electrically conductive medium. ... Sodium hydroxide (NaOH), also known as lye, caustic soda and (incorrectly, according to IUPAC nomenclature)[1] sodium hydrate, is a caustic metallic base. ... The chemical compound potassium hydroxide, (KOH) sometimes known as caustic potash, potassa, potash lye, and potassium hydrate, is a metallic base. ...

The series cell design by Yull Brown.
The series cell design by Yull Brown.[8]

Brown's design

Some models of water torches mix the two gases immediately after production (vs. the torch tip) making the gas mixture more accurate.[8] This electrolyzer design is referred to as "common-ducted",[7] and the first was invented by William A. Rhodes in 1966.[9] Oxyhydrogen gas produced in a common-ducted electrolyzer is commonly referred to as "Brown's gas", after Yull Brown who received a utility patent for a series cell common-ducted electrolyzer in 1977 and 1978 (the term "Brown's gas" is not used in his patents, but "a mixture of oxygen and hydrogen" is referenced).[8][10] Brown's torches also used an electric arc to increase the temperature of the flame (called atomic welding):[8] Atomic Hydrogen Welding (AHW) is an arc welding process that uses an arc between two metal tungsten electrodes in a shielding atmosphere of hydrogen and without the application of pressure. ...


As a fuel supplement

Oxyhydrogen improves emissions and economy of internal combustion engines when combined with air/fuel ratio and timing modification; these effects will be achieved in exchange for performance. The Hydrogen content of Oxyhydrogen affects the burn rate of fuels and lean combustion capabilities of internal combustion engines.[11][12][13][14] See: hydrogen fuel enhancement.


Heating

  • Sang Nam Kim claims "an energy generating apparatus using the cyclic combustion of Brown gas wherein a heat generating unit is heated to a temperature of 1,000°C".[15]

Klein's design

HHO gas or Klein gas is an oxyhydrogen mixture made by water electrolysis, which has been trademarked Aquygen by the firm Hydrogen Technology Applications. Dennis Klein's patent states that his electrolyzer differs from Yull Brown's in that it lacks the electric arc feature.[16] The claimed applications of HHO are practically indistinguishable from the original claims of Yull Brown.


The HHO trademark is associated with an unproven state of matter called magnegases, and a discredited theory about magnecules, [17] which is the basis for a number of fraudulent claims, and water-fuelled car scam attempts similar to Stanley Meyers' water fuel cell hoax. A popular scam attempt includes marketing "run your car on water" as an electrolysis based hydrogen fuel enhancement system in disguise, which is also most likely a subsequent scam attempt (See: Hydrogen fuel enhancement:Fraud considerations). A water-fuelled car is a hypothetical motor car that uses ordinary water as its fuel. ...


References

  1. ^ a b c 1911 Encyclopedia. "Oxyhydrogen Flame". (Available here Accessed 2008-01-19.)
  2. ^ a b c O'Connor, Ken. "Hydrogen", NASA Glenn Research Center Glenn Safety Manual. 
  3. ^ Calvert, Dr. James B. (2006-09-09). Hydrogen. University of Denver faculty page. Retrieved on 2008-04-05. "An air-hydrogen torch flame reaches 2045 °C, while an oxyhydrogen flame reaches 2660 °C."
  4. ^ Adiabatic Flame Temperature. The Engineering Toolbox. Retrieved on 2008-04-05. "Oxygen as Oxidizer: 3079 K, Air as Oxidizer: 2384 K"
  5. ^ Temperature of a Blue Flame. Retrieved on 2008-04-05. "Hydrogen in air: 2,400 K, Hydrogen in Oxygen: 3,080 K"
  6. ^ a b William Augustus Tilden. Chemical Discovery and Invention in the Twentieth Century. Adamant Media Corporation, 80. ISBN 0543916464. 
  7. ^ a b c d George Wiseman. Brown's Gas Book 2. Eagle Research, 59. ISBN 1895882192. 
  8. ^ a b c d e US4,014,777 (PDF version) (1977-03-29) Yull Brown Welding 
  9. ^ US3,262,872 (PDF version) (1966-7-26) William Rhodes Generator Patent 
  10. ^ US4,081,656 (PDF version) (1978-3-28) Yull Brown Arc-assisted oxy/hydrogen welding 
  11. ^ Mathur H.B., Das L.M. (1991). "Performance characteristics of a Hydrogen Fueled SI Engine using Timed Manifold Injection". Int. J. Hydrogen Energy (vol 16, pp. 115-117, 1991). 
  12. ^ Yougen Kong, Sam Crane, Palak Patel and Bill Taylor (January, 2004). "NOx Trap Regeneration with an On-Board Hydrogen Generation Device". SAE Technical Paper Series (2004-01-0582): p. 6-7. 
  13. ^ John Houseman and D.J. Cerini at the Jet Propulsion Lab., California Institute of Technology "On-Board Hydrogen Generator for a Partial Hydrogen Injection Internal Combustion Engine". Abstracts of papers of the American Chemical Society (1974) West Coat Meeting, Anaheim, Calif. August 12-16 (meeting abstract paper# 740600)
  14. ^ Hoehn FW, Baisley RL, Dowdy MW, "Advances In Ultralean Combustion Technology Using Hydrogren-Enriched Gasoline", IEEE Transactions on Aerospace and Electronic Systems 11 (5): 958-958 1975. (meeting abstract)
  15. ^ US6,443,725 (PDF version) (2002-9-3) Sang Nam Kim Apparatus for generating energy using cyclic combustion of brown gas 
  16. ^ US6,689,259 (PDF version) (2004-2-10) Dennis Klein Mixed gas generator 
  17. ^ J. M. Calo (November 3, 2006). "Comments on “A new gaseous and combustible form of water,” by R.M. Santilli (Int. J. Hydrogen Energy 2006: 31(9), 1113–1128)". International Journal of Hydrogen Energy (32): p. 1309-1312. doi:10.1016/j.ijhydene.2006.11.004

This article incorporates text from the Encyclopædia Britannica Eleventh Edition, a publication now in the public domain. Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 252nd day of the year (253rd in leap years) in the Gregorian calendar. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Anno Domini (or common era), in accordance to the Gregorian calendar. ... is the 95th day of the year (96th in leap years) in the Gregorian calendar. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Anno Domini (or common era), in accordance to the Gregorian calendar. ... is the 95th day of the year (96th in leap years) in the Gregorian calendar. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Anno Domini (or common era), in accordance to the Gregorian calendar. ... is the 95th day of the year (96th in leap years) in the Gregorian calendar. ... Also: 1977 (album) by Ash. ... is the 88th day of the year (89th in leap years) in the Gregorian calendar. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... Encyclopædia Britannica, the eleventh edition The Encyclopædia Britannica Eleventh Edition (1910–1911) is perhaps the most famous edition of the Encyclopædia Britannica. ... The public domain comprises the body of all creative works and other knowledge—writing, artwork, music, science, inventions, and others—in which no person or organization has any proprietary interest. ...


External links


  Results from FactBites:
 
Catheter with oxyhydrogen catalytic thermal tip - Patent 4796622 (2421 words)
Regardless, a stoichiometric ratio of oxyhydrogen is passed down the annular space of the catheter 10 between the outer tubing 18 and the inner tubing 24.
In operation, the oxyhydrogen gas reaches the catalytic chamber 28, encased by the metallic tip 20, where a piece of palladium sponge 30 resides, and chemical combustion is started by the catalytic action of the palladium sponge on the mixture of oxygen and hydrogen.
The oxyhydrogen passing down the annular space between the outer tubing 18 and the inner tubing 24 is progressively heated by the high temperature steam that is evacuated through the inner tubing 24.
  More results at FactBites »

 

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