[Stoves] MANTLE LAMP PHYSICS

Fri Feb 9 09:16:29 CST 2007

Dear Paul, George and All:

Lighting is arguably as important as cooking for a continuing 
civilization, so I'm so glad to see a discussion of mantle lamps finally 
on these sites. Maybe Tim Miles needs to start a separate discussion group.
------------------------------------------------------------------------

I'm sending this particularly to Paul, since I haven't followed the 
whole mantle lamp discussion, but have had a LONG interest in both the 
physics and chemistry of mantle lamps.  If I have missed any of the 
important players, please forward to them.

I was involved in VERY high temperature material science at MIT for 18 
years, so came to know my way around in the >2,000C world of materials 
(excludes 98% of all materials).  I was naturally fascinated by the 
mantle lamp, which operates probably below 1500 C (since no air flame 
exceeds 2100C except acetylene).  (See 
http://en.wikipedia.org/wiki/Gas_mantle  for an excellent history of the 
mantle lamp).

It is interesting the way in which Welsbach discovered the mantle lamp 
properties of thoria.  He was a student of Bunsen, separating various 
rare earths (from Trona?) .  He would make the nitrates, then separate 
them by fractional crystalization, each day getting purer.  At the end 
of the day he would soak a wad of cotton in the purified nitrate and 
pyrolyze it in a Bunsen burner to give a nice bright light.  Working 
with Thoria, he noticed that as the thoria got purer and purer, the 
light got brighter and brighter, but when he got really pure there was 
NO light.  This is due to the introduction of oxygen vacancies in the 
thoria by ceria the principle impurity.  No CeO2, no vacancies, no 
light!  This may well be the first semiconductor research done.  (I 
don't think the white light is due to rare earth lines as it says in 
Wiki, but I'll let Prof. George Honig join the discussion of the band 
structure of Thoria.  Incidentally, ThO2 probably has a band gap of over 
4 EV (and a melting point of 3493K, 3220 C according to my "Free ENergy 
of Binary Compounds" Atlas, available at Woodgas.com). 
------------------------------------------------------------------------

It is very difficult to fabricate materials with melting points in 
excess of 1800C (attainable  in relatively new zirconia fiber insulated 
furnaces).  There are other possible mantle material candidates, 
including particularly stabilized zirconia (same group as thoria) and 
Hafnia. 

More Light for Mankind (more use for biomass)...

Yours truly,      TOM REED

Michael N Trevor wrote:
> ----- Original Message ----- 
> From: "Paul S. Anderson" <psanders at ilstu.edu>
> To: "Frans Peeters" <peetersfrans at telenet.be>; <eddie at britelyt.com>
> Cc: "Harry Stokes - alcohol" <hstokes at blazenet.net>; "Stoves"
> <stoves at listserv.repp.org>
> Sent: Saturday, February 03, 2007 3:51 PM
> Subject: Re: [Stoves] FW: MANTLE LAMP TESTS
>
>
>   
>> Frans,
>>
>> Thanks for the message and for the efforts.
>>
>> Last month I met Mr. Eddie Draper who makes the Britelyt mantle
>> lanterns, and he
>> has a model that runs on any of the alcohols.  A VERY nice product and
>> I showed
>> one at ETHOS.  Sells for about $200 including a cookstove substitute
>> top.  Visit    www.britelyt.com   for info.
>>
>> Britelyt has a stronger mantle than what is common for campstoves.  Any
>> details
>> would need to come from Eddie, who is receiving a copy of this message.
>>
>> Eddie:  Thanks.  The alcohol lantern was performed well at ETHOS.  See
>> photo of
>> it in the photo section of Tom Miles report at     bioenergylists.org    .
>>
>> Paul
>>
>>
>> -- 
>> Paul S. Anderson, Ph.D., Geography professor - Emeritus
>> Telephone:  USA-309-452-7072 (residence and office)
>> Internet site:  www.ilstu.edu/~psanders
>> For my gasifier stoves info, go to:
>> http://bioenergylists.org/contributors#Paul_Anderson
>>
>>
>> Quoting Frans Peeters <peetersfrans at telenet.be>:
>>
>>     
>>>
>>>
>>>
>>>
>>> Dear Paul ,
>>>
>>>    I have tested a camping gass lamp with a mantle of ThO2 .
>>> It is very very weak ! It breaks down in powder by toutching . Gamma
>>> counting 3730 Bq eq . Alfa and beta contamination risk is easy . So it
>>> is no idea to restart this production .
>>>
>>> In a museum ,I saw  information ,the material is ThO2 + CeO .
>>> I did the test with CeO only .
>>> Ceriumoxyde was dissolded in warm nitric acid .
>>> Dryed on silk , cellulose and glas microfiber filter .
>>> Only the glass fibre was strong anough ,but the sodium gave a yellow
>>> color . The wanted  bright effect with CeO only mantle, was
>>> unsuccesfully .
>>>
>>> A vacuum tube with a heater surrounded by white calsite ,CaSO4 cristals
>>> . Is used for gamma radiation dosimeter memory .
>>> Afterwards heated in a photomultiplier luminometer , it gives  light in
>>> proportion to
>>> Accumulated radiation .
>>> Overheated to clear red heat, it  gave no  extra white, glow wanted for
>>> use as mantle !
>>>
>>> Light measurement : with TP 60 SILICON SENSOR at 1 foot gives :(
>>> 1uA=1Lux ) TEA candle =14uA visible and 6 uA IR invisible . Total 20uA
>>> light . So 14 uA/ 1 Candela (Cd ) Gass ThO2 WICK lamp gives 40 uA light
>>> +23 uA IR light ; Total 63 uA . So +- 3 Candelas.
>>>
>>> An US firm sels mantles for ALLADIN  kerosin lamps for 10 $. They do not
>>> answer on questions about mantle specs ; ThO2 or not .
>>>
>>> I finish this old road to extra light .
>>> May be AJH has old methods with rare earth metals to make mantles ?
>>> I lost a stove info about that .
>>>
>>> Better think about NEW technologie . 20 candela LED 20°angle ,  0,064
>>> watts for 2 $ !
>>>
>>> Greetings
>>> Frans
>>>
>>> -----Oorspronkelijk bericht-----
>>> Van: psanders at ilstu.edu
>>> Verzonden: zaterdag 4 november 2006
>>> Aan: Frans Peeters
>>> Onderwerp: Alcohol Mantle Lamp.
>>>
>>>
>>> Dear Martin, Frans
>>>
>>> Interesting comments about wicks.  I do not know how I will utilize that
>>> information.  But here is a possible issue:
>>>
>>> I want to create light by using the "gas mantle" approach.  "gas
>>> mantle".
>>>
>>> An incandescent gas mantle, gas mantle, or Welsbach mantle is a device
>>> for generating bright white light when heated by a flame. The name
>>> refers to its original heat source, existing gas lights which filled the
>>> streets of Europe and North America in the late 19th century, mantle
>>> referring to the way it was hung above the flame. Today they are still
>>> used for portable camping lanterns and pressure lamps. [edit] Mechanism
>>> They work by utilising the heat of a flame, in modern portable
>>> applications produced by using kerosene or liquified petroleum gas, to
>>> heat them up to around 1000 degrees celsius. At this temperature, they
>>> are sufficiently hot to radiate an intense white light as a consequence
>>> of the spectral lines of rare earth elements in the mantle. The light is
>>> not produced through black body radiation, since the temperature is too
>>> low to generate white light.
>>>
>>> Modern mantles are made of ramie-based artificial silk or rayon. When
>>> the mantle, a small net bag, is attached to the lamp and used for the
>>> first time, the heat burns away the bag's cellulose and converts the
>>> in-soaked rare earth nitrates into a rigid, but very fragile, metal
>>> oxide structure.
>>>
>>> Since thorium is radioactive......
>>> (end of quotation.  Much more info is there.)
>>>
>>> Now for my questions and project:
>>> I want to create light by using the "gas mantle" approach.  Seems like
>>> I need to
>>> get about 1000 deg C heat (direct flame) to a mantle.
>>>
>>> Is there any wick mechanism that can yield such heat?  What would be
>>> the fuel? Can alcohol accomplish that heat (because I have invented a
>>> nice alcohol burner
>>> that vaporized the liquid and can send the alcohol vapor as little jets
>>> (call them point-type "wicks?) in any configuration that is specified.
>>>
>>> I have tried this with a very rudimentary arrangement with a bag-type
>>> mantle, and only got small areas to glow for short times.  I think part
>>> of the "trick" is to get the gases to burn right at the position of the
>>> mantle.
>>>
>>>  I simply want to give mantle-light via alcohol fuel to a billion
>>> people, or more.
>>>
>>> I hope each of you will respond.
>>>
>>> Paul
>>>
>>>
>>>
>>>
>>> --
>>> No virus found in this outgoing message.
>>> Checked by AVG Free Edition.
>>> Version: 7.5.432 / Virus Database: 268.17.19/663 - Release Date:
>>> 01/02/2007 14:28
>>>
>>>
>>>
>>>       
>>
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