Talk:Condenser (laboratory)
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Changes made! -- graham/grahams?
[edit]updates: i've read what you guys have written, and i mostly (or maybe entirely) agree. i've made many/all of the changes you've suggested, and i also uploaded some additional images.
graham/grahams: does anyone have a definitive answer? who is this graham/grahams guy? and what is his actual name? if anyone finds a source, please update the article. — Preceding unsigned comment added by Fleximus (talk • contribs) 12:48, 2 June 2011 (UTC)
I suspect that the "Graham condenser" is named after Scottish chemist Thomas Graham (1805–1869). He eventually rose to become Master of the Mint, but he was also consulted by the Board of Inland Revenue on matters concerning the taxation of alcohol (ethanol).
- In 1852, he was asked to determine the accuracy of a method that beer brewers used to estimate the fraction of alcohol in their beer. (Graham found that the method wasn't accurate. His report is here. )
- In 1852, the British medical journal The Lancet, which had established a committee to determine presence of adulterants in foods and drinks, asked him to confirm or refute a widespread rumor that British beer makers were using strychnine instead of hops to give their beers a bitter taste. (Graham found no strychnine in British beer. His report is here.)
- In 1856, he was asked by the Board of Inland Revenue to find a way to denature alcohol ; he recommended using methanol. (His report is here.)
Graham's work on determining the alcohol content of beer involved distilling the wort in a retort in order to separate the alcohol (as stated on p. 255 of the report linked above). Later, distilling flasks that were connected to Graham condensers were used for that purpose, as is illustrated on page 320 of this 1975 article. I suspect that the switch from using retorts to using Graham condensers probably took place in the late 19th or early 20th century, when glassblowers were able to fabricate such complicated glassware at a reasonable price. (However, I still haven't found any proof of that.) I also suspect that although Graham probably never used such a condenser, it was probably named after his method of analysis as much as it was named after him.
VexorAbVikipædia (talk) 01:20, 10 April 2017 (UTC)
Accuracy Disputed: Incorrect / confusing nomenclature
[edit]I strongly believe the naming and descriptions on this page are either incorrect or confusing, specifically with regards to the coil, Grahams & Friedrich condensers. The article suggests, and illustrates, that a Grahams condenser can be run with the vapour traveling around the cooling spiral. If you investigate this with the big name glassware companies, this is a COIL condenser (or Dimroth if the water enters and leaves in a similar location). The version wherein the vapour travels through the spiral is the GRAHAMS condenser. I see people mixing the two up even on the better science forums, and then arguing over the technicalities due to the naming error. GRAHAMS condensers are also called INLAND REVENUE condensers.
A Friedrichs condenser is not simply a bigger COIL condenser. Inside, there is a cold finger with a spiral groove molded into it's edge. The finger is almost the same size as the outer glass shroud, forcing the vapours into intimate contact with the cold finger. This is an attempt to provide a large flow path but to also avoid solvent bypassing the the cold surfaces; e.g. in a COIL condenser, driving the solvent through aggressively can allow some of it to creep around the edges of the coil, which is why jacketing is sometimes used. The Friedrichs is another approach to that.
"A Graham condenser in the first configuration is used to prevent the toluene from boiling away while it is being refluxed."
That is a COIL condenser, NOT a Grahams. Note the water entering the sides and running through the coil.
Search the catalogs of Sigma, Quickfit and ChemGlass for these names, and you'll see they are being incorrectly transposed in the article. The only time there is a crossover is when Sigma call a COIL condenser a Coil (Grahams). However, this condenser is made by QuickFit in the UK, and checking their own page (SciLabWare), you'll see they have a distinct naming policy that differentiates the two.
I would rate this article as currently being critically flawed and in need of serious repair. [editor name not given]
- Then fix it. It seems you have the knowledge and sources. 71.213.233.229 (talk) 15:10, 6 February 2011 (UTC)
- A better initial response would be to note that catalogs are not sources for encyclopedic knowledge. While in OChem areas they are often correct in their representations of glassware, they are nevertheless not without errors, and are (for reasons of commercial aims) not acceptable sources here. 173.15.56.201 (talk) 00:51, 12 February 2015 (UTC)
- Otherwise, this is a singularly unhelpful response, and does not invite the improvements to the encyclopedia that are desperately needed. There are individuals with subject matter expertise that will never care to involve themselves in the arcane markup technical skill that this place has only recently begun to address. If the person's suggestions are valid (and I will look to them now), whoever can, should implement them. The "just fix it" mantra is one we too often hide behind to maintain mediocrity. 173.15.56.201 (talk) 00:48, 12 February 2015 (UTC)
- A better initial response would be to note that catalogs are not sources for encyclopedic knowledge. While in OChem areas they are often correct in their representations of glassware, they are nevertheless not without errors, and are (for reasons of commercial aims) not acceptable sources here. 173.15.56.201 (talk) 00:51, 12 February 2015 (UTC)
Pictures/Drawings
[edit]Some pictures or drawings of the different glassware would improve the article immensely! Probably start by checking if there are any available on Commons. Larsenbagvendt (talk) 10:50, 4 June 2010 (UTC)
- Sorry, didn't see the gallery there at the end of the article. May I suggest moving some of the pictures up into the article, or at least refer to the gallery? Larsenbagvendt (talk) 10:53, 4 June 2010 (UTC)
- Done. One pair of colour-carified images move up, to better introduce the subject, before the fact dist image. 173.15.56.201 (talk) 00
- 52, 12 February 2015 (UTC)
West condenser
[edit]There is no mention of a West condenser. Isn't this a Liebig with a narrower jacket? —Preceding unsigned comment added by 151.204.242.197 (talk) 17:23, 12 February 2011 (UTC)
Direction of the coolant flow
[edit]Even though the text tries to correct this mistake, a number of the diagrams have the coolant running in the wrong direction. The flow of the vapors and that of the coolant is supposed to be in opposite direction. (Coolant enters at top, exits at bottom.) Jcwf (talk) 22:42, 31 March 2012 (UTC)
- Are you sure about this? In all setups I have ever seen, the coolant was entered at the bottom inlet... otherwise, it would just spray down the outside of the jacket, without surrounding the inner tube\coil. For example: www.chem.ucalgary.ca/courses/351/laboratory/reflux.pdfBlob800 (talk) 22:37, 8 July 2013 (UTC)
- Increase efficiency and lower thermal shock would be gotten from counter-current flow, starting at the top. Concurrent flow, while it may be the standard practice, will give poorer performance. For details of why it has lower performance and higher thermal stress, see Countercurrent exchange. 47.21.153.202 (talk) 21:07, 28 January 2014 (UTC)
- This change cannot be made without a non-wikipedia source. While the theoretical argument being made is sound, in standard practice (says this mid career practicing OChemist), e.g., in reaction refluxing situations, thermal shock is of little or no concern; the goal, rather, is to accomplish essentially all condensation of solvent vapour in the first fifth or quarter pf the condenser, leaving the remainder to capture last vestiges. That is to say, there is no fractionation being attempted, whatsoever. In this situation, the chemist may not take pains to consider the theoretical efficiency (a conjecture that may underpin why the "in all" comments from Blob800. Let's resolve it, reporting what sources say, s'il vows plait. 173.15.56.201 (talk) 01:00, 12 February 2015 (UTC)
- Consider the Friedrichs type. How do you plan on filling the cold finger jacket without it coming in the middle?
While some condensers will allow the water to flow in either direction some require the water to flow from top to bottom, or will be significantly more annoying to set up.149.171.157.13 (talk) 01:01, 27 April 2015 (UTC)
Sources
[edit]One reason that the foregoing issue exists, is that apart from Wiberg, this article is very poorly sourced. In this first pass, I will try to add, as "Further reading", further absolutely reliable sources, for futures editors to use. They will focus on German and UK practice. Cheers. 173.15.56.201 (talk) 01:02, 12 February 2015 (UTC)
Issue with changes to citation formats
[edit]I have been engaging in a major academic sort of edit of the content of this article, as explained above, putting good source of information into the "Further reading" section, then slowly mining these sources for content related to the article. (The sources chosen are from a career of several decades in the field, spanning two continents and familiar with more.)
The editing has hit a snag as a result of well meaning efforts on the part of another editor to standardize the formatting of citations. To make the point, note the following. The useful, easily accessible content of the text in the "Further reading" section:
- Erich Krell, 1982, "Handbook of Laboratory Distillation, with an Introduction to Pilot Plant Distillation" (Series, TechnIques and instrumentation in Analytical Chemistry, 2nd edn.), Amsterdam:Elsevier, ISBN 0444997237, see [1] and [2] for further leads.
Is not the same as what one has at their fingertips from this edited text, made uniform by way of templates:
- Krell, Erich (1982). Handbook of Laboratory Distillation: With an Introduction into the Pilot Plant Distillation. Techniques and instrumentation in Analytical Chemistry (2nd ed.). Amsterdam: Elsevier. ISBN 9780444997234.
Please review the above, both as it appears here, and by clicking on edit, so you can see how different the two appear in markup (which is what we have to deal with while immersed in the editing).
I would make the simple points, (1) that in the second format, I have lost information that was in the first format, that I was using to create content, and (2) for regular subject matter experts that are editing, the first format is the more useful, and less cumbersome in markup.
As WP policies indicate that there is no single correct way to do science citations (and that one should seek consensus before making major changes to citation formats), I am asking that we hold on converting sources to templates until after the expert work on the content is finished. After that point, we can have a discussion about how best to convert to a uniform style (as an appropriate finishing touch, "end game" activity, rather than a requisite middle game one).
I have therefore asked the well meaning editor at his talk page—and am asking any others interested, by writing here—to allow me to continue my content work, without having to deal with major changed to the citations I add (edits which make my access to content for editing problematic).
Let's leave the format changes until later. Can we? After the major content editing is done,we can then discuss how to keep content, but make it all more uniform.
Le Prof 7272 71.239.87.100 (talk) 03:37, 26 February 2015 (UTC)
- Sounds like a good plan. Did not realize major work was underway. Just unifying various cite formats -- there were several different methods in use. The https://aussiedistiller.com.au/books/Chocaholic/ does not work, so I removed it. AManWithNoPlan (talk) 03:56, 26 February 2015 (UTC)
- links like [3] are deprecated because they look like references and they don't tell you what they are. They should be like Google books and include link texts. AManWithNoPlan (talk) 14:33, 26 February 2015 (UTC)
- Points taken—the reason for the two refs here was that the first took you to the actual citation without giving access to the content, and the second gave actual content. I will find a replacement for the latter, because it appears to have been taken down in a Comodo certificate issue (relation to the ongoing Lenovo-Superfish fiasco circumstantial?). THanks for the understanding. Will be back to it tonight. Le Prof. — Preceding unsigned comment added by 71.239.87.100 (talk) 15:20, 26 February 2015 (UTC)
- Here is the Krell source, in PDF: [4], a test, to see if this alternative approach works. 71.239.87.100 (talk) 15:31, 26 February 2015 (UTC)
- Points taken—the reason for the two refs here was that the first took you to the actual citation without giving access to the content, and the second gave actual content. I will find a replacement for the latter, because it appears to have been taken down in a Comodo certificate issue (relation to the ongoing Lenovo-Superfish fiasco circumstantial?). THanks for the understanding. Will be back to it tonight. Le Prof. — Preceding unsigned comment added by 71.239.87.100 (talk) 15:20, 26 February 2015 (UTC)
- links like [3] are deprecated because they look like references and they don't tell you what they are. They should be like Google books and include link texts. AManWithNoPlan (talk) 14:33, 26 February 2015 (UTC)
Spiral vs Helix
[edit]There are numerous locations where the various structures of the condensers are referred to as a spiral. A spiral is typically 2D and the radius increases as you proceed around the spiral. I think a better word to use would be helix as that does describe it accurately. Is there any particular reason why they are called spirals and not helices?149.171.157.13 (talk) 01:03, 27 April 2015 (UTC)
English nomenclature
[edit]Being a non-native speaker of the English language, I'm not sure what is going on here:
This article freely mixes four very distinct items, namely coolers, reflux condensors, distillation condensors and distillation columns under the same name.
I find this very odd, and rather disturbing from a safety point of view.
Is this common practice, or have i just stumbled over the worst wikipedia article that is older than a week and longer than ten lines?
Best regards, --Maxus96 (talk) 00:43, 30 November 2015 (UTC)
- it is pretty lose with language. The whole condenser area of Wikipedia was recently revamped and greatly improved by a group of people (not me), but in the huge influx of useful information and pictures, the quality of the language exactness greatly suffered AManWithNoPlan (talk) 01:39, 30 November 2015 (UTC)
- Well, i don't know the original state, but i can hardly imagine this being an improvement. The "air cooled types" described simply are not condensers, but distillation columns. That's a completely different subject, imo. Using a Graham-type cooler as a condenser in any way is bad practice and frankly dangerous.
- And what's that with the Liebig cooler? You basically say that one can abuse its inner tube as a column. I'd call that shooting yourself in the foot. Air convection will cause the upper part of the tube be heated by the condensing liquid in the lower part. You would do equally good without any tube, imo. The whole idea of using a column is letting the condensing and re-evaporating liquid create it's own equilibrated boiling-point temperature gradient. --Maxus96 (talk) 02:20, 30 November 2015 (UTC)
- I agree about such abuse, but I assume that it is common practice in classes since it means one less piece of glassware to buy and store. AManWithNoPlan (talk) 15:26, 30 November 2015 (UTC)
- Well, i'm glad my universities in Germany valued our lab training higher than that.
- But at least wikipedia must tell what proper equipment looks like. How should a student ever know? --Maxus96 (talk) 23:26, 7 December 2015 (UTC)
Liebig condenser: forerunners
[edit]The simple Liebig condenser had a number of forerunners, as Jensen states in his article on the subject: Jensen, William B. (2006) "The origins of the Liebig condenser," Journal of Chemical Education, 83 : 23. (Available at: University of Cincinnati (Ohio) )
The identity of the inventor of the Liebig condenser is disputed: Two men could claim to have invented it in 1771, and another two could claim to have invented the condenser later and independently.
(1) In 1781, an anonymous pamphlet was published in French, presenting a retort with a condenser, which, the author proposed, could be used to distill brandy and salinate seawater aboard ships at sea. The pamphlet was: Nouvelle Construction d'Alambic pour faire toute sorte de distillation en grand, … (New construction of a retort in order to do every sort of distillation on a large scale, … ), 1781. On the title page of a copy that was in the collection of the state library of Cassel, Germany, was written "par Jean-Hyacinthe de Magellan" ([written] by Joao Hyacinth de Magellan). Magellan (1723–1790) was a Portuguese friar who settled in London and who wrote a book on heat (Essai sur la nouvelle théorie du feu élémentaire et de la chaleur des corps [Essay on the new theory of elemental fire and on the heat of bodies] (London, 1780)). (Speter, 1909b), p. 3 and (Schelenz, 1910), p. 1978 both mention this attribution to Magellan, although Schelenz suspected that the pamphlet had actually been written by Lavoisier. On p. 5 of the pamphlet, the Préface stated: "La première idée de la Machine distillatoire dont il sera question dans cet Ecrit, remote à l'année 1770. Il en fut d'abord exécuté différens modèles en petit, & notamment un dans le mois de Janvier 1773 ; enfin, peu de temps après, par les ordres de M. de Boynes, alors Ministre de la Marine, la Machine fut exécutée à Paris en grand, … " (The first idea of a distillation device that is the subject of this work, arose in the year 1770. Different models were executed at first on a small scale, and in particular one in the month of January 1773 ; at last, shortly afterwards, at the order of Mr. de Boynes, then Minister of the Navy, the device was executed in Paris on a large scale, … ) Illustrations in the pamphlet show a retort to which a tube was fitted. The tube carried the retort's vapors through a rectangular box, which acted as a condenser and in which cold water flowed from the condenser's lower end to its upper end — a counter-current condenser.
(2) The other claimant to being the earliest inventor of the Liebig condenser was the German scientist Christian Ehrenfried Weigel who published an article about his condenser in 1771: Weigel, Christian Ehrenfried, Observationes chemicae et mineralogicae (Goettingae [Göttingen], (Germany): 1771). (in Latin) As Fig. 2 on the last page of his book, he shows his condenser. The parts are identified in a footnote on p. 11, and the condenser's construction is explained on pp. 8–9. The condenser consisted of two coaxial tubes made of pure tin. The condenser was tilted; at the condenser's lower end, the gap between the tin tubes was sealed with sheet metal; the condenser's upper end was open, allowing water to be discharged into a funnel, which emptied into a drain. A collar around the open upper end prevented the discharged water from streaming down the condenser. An inlet tube in the condenser's lower end allowed water to enter the condenser from an elevated reservoir, which discharged into a funnel that was joined to the condenser's inlet. A glass tube that extended from a retort at the condenser's upper end passed down the middle of the condenser's inner tin tube; at the condenser's upper end, the glass tube was supported by strips of sheet metal that were soldered onto the tin tube's inner surface and that held the glass tube in the center of the condenser. (See Fig. 4.) This arrangement avoided the danger of the glass tube's shattering, as might happen if the glass were in direct contact with the cold water of the condenser while a substance with a high boiling point were being distilled. In a second volume of his book on chemistry and mineralogy — Weigel, Christian Ehrenfried, Observationes chemicae et mineralogicae, part 2 (Gryphiae [Greifswald], (Germany): 1773). (in Latin) — Weigel mentioned a modification of his original condenser in which the inner tin tube had been replaced with a glass tube, which was secured to the outer tin jacket by plaster. Weigel also devised a clamp to hold his condenser; the clamp consisted of a pair of fork-shaped jaws which were closed by a screw.
(3) According to Jensen, in 1779 "P.J. Poisonnier" described a condenser of his own design. However, "P.J. Poisonnier" was actually P.I. Poisonnier — Pierre-Isaac Poissonnier — physician to Louis XV. In 1763, the French navy built and tested a still that he had designed in order to allow ships at sea to produce fresh water from seawater.
- Brunner states in his article on desalinization — Brunner, Jean (1875) "Distillation de l'eau de mer pour en obtenir de l'eau potable" (Distillation of seawater in order to obtain drinking water), La nature: revue des sciences et de leurs applications aux arts et à l'industrie, 4 : 268–270 ; see p. 269 — "Le premier projet qui ait reçu une exécution pratique est de Poisonnier, médecin du roi ; il date de 1763." (The first project [to desalinate seawater aboard a French naval ship] that was executed in practice was [that] of Poisonnier, physician to the king ; it dates from 1763.) Brunner cites as his source Lavoisier's account of Poisonnier's work: Ministry of Public Education, ed.s, Œuvres de Lavoisier (Paris, France: Imprimerie impériale, 1868 ; reprinted: New York, New York: Johnson Reprint Corp., 1965), vol. 4, p. 766. However, the illustration of Poisonnier's still on p. 767 reveals that it was a conventional still, and that it did not employ a condenser resembling Liebig's.
- However, Poisonnier did subsequently design another still for producing fresh water from seawater aboard a ship. He described it in: P. I. Poisonnier, Appareil distillatoire présenté au Ministre de la Marine (Paris, France: 1779). The still is depicted as Fig. 8 on p. 170 of: Dujardin. Jules, Recherches rétrospectives sur l'art de la distillation: … (Paris, France: (Self-published), 1900), pp. 169–170. A retort containing seawater is shown on the left. A tube extends from the retort through a rectangular box to which are attached an inlet pipe on the box's right end, to supply cold water from the tank (O), and a discharge pipe on the box's left end.
(4) The Swedish-Finnish scientists Jakob Gadolin and his son Johan Gadolin also designed condensers similar to Weigel's.
- In 1778, Jakob (or Jacob) Gadolin proposed condensers for use in distilleries and in laboratories. These condensers also consisted of a metal jacket which surrounded the discharge tube from a distillation vessel and through which a countercurrent of cold water flowed. (See: Gadolin, Jakob (1778) "Förslag at föbättra Brännerie-slangen" (Proposal for an improved distillery hose [i.e., condenser]), Kungliga Vetenskaps Akademiens Handlingar (Proceedings of the Royal Academy of Sciences), 39 : 283–289. [in Swedish] German translation: Gadolin, Jacob (1783) "Vorschlag, die Schlange beym Brantweinbrennen zu verbessern" (Proposal to improve the condensers in distilleries), Der Königlich Schwedischen Akademie der Wissenschaften Abhandlungen, 40 : 271–276. [in German])
- In 1791, Johan Gadolin proposed a condenser for use by commercial distillers. (See: Gadolin, Johan (1791) "Beskrifning på en förbåttrad Afkylnings-Anstalt vid Brånvins-Brånnerier" (Description of an improved cooling device of brandy distillers), Kungliga Vetenskaps Akademiens Nya Handlingar (New Proceedings of the Royal Academy of Sciences), 2nd series, 12 : 193–213. [in Swedish] German translation: Gadolin, Johann (1792) "Beschreibung von einer neuen Vorrichtung zum Abkühlen bey den Branntweinbrennereien" (Description of a new apparatus for cooling at brandy distilleries), Chemische Annalen … , pp. 368–379.)
(5) Jensen also cited a discussion of Weigel's condenser by the German chemist Johann Friedrich August Göttling, who urged pharmacists to use Weigel's condenser (instead of the traditional still) because it was compact. (Göttling was a former student of Weigel.) See: J. F. Göttling, Taschenbuch für Scheidekünstler und Apotheker (Pocket book for [chemical] analysts and apothecaries), 15th ed. (Weimar, (Germany): Hoffmannische Buchhandlung [Hoffmann's bookstore], 1794), pp. 129–135.
(6) Liebig's contributions to the development of the laboratory condenser seem to have been: (1) eliminating Weigel's inner metal tube and allowing direct contact between the cold water in the condenser's jacket and the glass tube containing vapor from the distilling flask ; and (2) when distilling small quantities, using a glass tube, instead of a metal one, as a jacket for the condenser. However, so far I haven't found any evidence that he ever fused a glass jacket to the inner tube carrying the hot vapor.
- In — Geiger, Philipp Lorenz and Liebig, Justus, ed.s, Handbuch der Pharmacie … , 5th ed. (Heidelberg, Germany: C.F. Winter, 1843), § 420, "Destillation," pp. 172-175 — on p. 173, Liebig mentions the condensers of Gedda, Beindorf, and Göttling; however, the first two are industrial (not laboratory) condensers.
- Liebig, Justus von; Poggendorff, J.C.; Wöhler, Fr., ed.s, Handwörterbuch der reinen und angewandten Chemie, vol. 2 (Braunschweig, (Germany): Friedrich Vieweg und Sohn, 1842), article: "Destillation," pp. 526–554. On p. 532, Fig. 29, a condenser is shown in which the inner glass tube containing the hot vapors from the distilling flask is now in direct contact with the cooling water in the condenser's jacket. Fig. 30 on p. 533 shows a condenser with a glass (not metal) jacket, for distilling small batches of material.
(7) Reviews of the history of distillation:
- Forbes, Robert J., A Short History of the Art of Distillation: … (Leiden, Netherlands: E.J. Brill, 1970).
- Kahlbaum, Georg W. A. (1896) "Der sogenannte Liebig'sche Kühlapparat" (The so-called Liebig condenser), Berichte der Deutschen Chemischen Gesellschaft, 29 : 69–71.
- Schelenz, Hermann (1910) "Nochmals Kühler nach dem Gegenstromprinzip und seine Erfinder" (Once again, the condenser based on the counter-current principle and its inventor), Zeitschrift für angewandte Chemie, 23 : 1978–1980.
- Schelenz, Hermann, Zur Geschichte der Pharmazeutisch-Chemischen Destilliergerate [On the history of pharmaceutical [and] chemical distillation apparatuses], (Berlin, Germany: Julius Springer, 1911).
- Speter, Max (1908a) "Die historischen chemischen Originalapparate des "Deutschen Museums von Meisterwerken der Naturwissenschaft und Technik" zu München" (The historic original chemical apparatus of the German Museum of masterpieces of science and technology at Munich), Zeitschrift für angewandte Chemie, 21 (14) : 625–632.
- Speter, Max (1908b) "Geschichte der Erfindung des "Liebig'schen Kühlapparat" (The history of the invention of the "Liebig" condenser), Chemiker Zeitung, 32 (1) : 3–5.
I'm still reviewing these sources (some of them contradict others). However, I intend eventually to modify the subsection on the Liebig condenser to include material from these sources.
VexorAbVikipædia (talk) 23:23, 5 April 2017 (UTC)
Can't make sense of Widmer's condenser
[edit]I cannot make sense of Widmer's condenser. There seem to be no way to remove the heat of condensation. Either the description is wrong, or the device's purpose was not to condense vapors.
Was the device merely intended to ensure better mixing or a more uniform and constant temperature in the outgoing vapor stream?
Could it be that the device was only Widmer's idea of a "better condenser", but he did not understand the physics of heat transfer and did not see the need for a coolant flow? Was his design ever used in practice, by Widmer or anyone else?
Or is the diagram wrong, and the middle "rod" was actually a cold finger with internal water flow (as in Friedrichs' design)?
Also, I cannot see the point if having the vapor flow in countercurrent next to itself, twice. That arrangement would make for a pecular heat flow between the first, middle, and last third of the vapor stream. To what purpose?
--Jorge Stolfi (talk) 18:49, 18 February 2020 (UTC)
- Try reading about it in the revision before your edits. It said it was cooled after the "tube". Btw. numbers (marked with #) in the section "Widmer's condenser" is referring to numbers on the figure. Christian75 (talk) 21:57, 18 February 2020 (UTC)
Photograph
[edit]Is there a better picture to illustrate the lead than File:Distillation 2-3.jpg? I can identify at least three serious safety hazards in it. (1) Distilling from an isomantle; a no-no except for purifying large volumes of solvent. (2) No means of removing the heat source in a hurry, such as a scissor jack. (3) No support for the flask other than the mantle. If the clamp twists, the GG joints either side of the anti-splash bulb will spring. If the liquid is flammable...
I don't much like the way that the water supply is out of reach or the kinks in the hose either. Narky Blert (talk) 10:28, 23 February 2020 (UTC)
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