Talk:Denis Papin

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Could the author of this article please identify their source(s)? User 346789

Nothing at all to do with Savery?
Looking at the designs in the patents, they appear to work nothing at all like Savery's engine. Nevertheless, this article claims Savery's design was copied from Papin's.

For instance, the second diagram, showing a pump, appears to use steam pressure to push water out of the lower part of the cylinder. In contrast, Saverly's engine used the vacumme created by condensing steam to pump the water. In Papin's design the water is pushed on, in Savery's it is pulled.

I also have serious doubts about the effectiveness of this design, notably in comparison to Newcomen's version. For one, the cylinder remains in contact with the water throughout the cycle, which will lead to considerable condensation. This means that much more steam will have to enter the cylinder in order to build up pressure. In comparison, the pumping action of Newcomen's design was completely separate from the power cycle, allowing the cylinder to remain hotter. Additionally, given the materials and construction techniques of the era, the amount of pressure supplied by the boiler would likely be quite low by later standards.

While I don't mean to diminish Papin's work, claiming that Savery's is based on it appears odd. Notably hen there appears to be historical evidence that Savery actually got his design from Raglan Castle, which pre-dates Papin as well.

Does anyone have a real historical source for this?

Maury 17:34, 28 April 2006 (UTC)

Yes, Papin did invent a steam engine, with the same idea of condensing steam to suck water, then push it to raise the water up. He did that in 1675, when he was working at Cassel, when he was asked to raise the water of the Fulda on the Hill. Papin relates this in a letter to Leibniz, not with many details. Because this machine was broken, and taken away by the river, after a very cold winter.

Comparing Thomas Newcomen engine with Papin 1707 pump...You have to consider that the steam input in the pump is not in direct contact with the water to pump. There is in between a thick and hollow floater. By the way, the pump uses superheat : when it comes into the cylinder, the steam is over heated by the red iron bar, held on the top of the cylinder, right under the safety valve. The floater also has a hollow tube in its center, so that the red iron can find its place, when the water is up.

This pump is also a sort of accumulator of energy : once the water is pumped in the upper reservoir, the air presses on its surface, and so you have water under pressure, to activate a paddle wheel, with no need to have the steam pump working.

Hope I make mayself undertand, my english is not so good !

Vincent Rey, Blois, in France.

I must say that the following paragraph on the article is totaly false :

"He continued to work on steam engines for the next fifteen years. In 1705 he developed a second steam engine with the help of Gottfried Leibniz, based on an invention by Thomas Savery, but this used steam pressure rather than atmospheric pressure. Details of the engine were published in 1707."

1 : Papin has worked on many things, not only on steam engines.

2 : the 1705 is a steam pump, not a steam engine. And Papin did not do that "with the help of leibniz"...even if Leibniz always shared the enthousiasm of Papin.

3 : the 1705 steam pump is not at all based on savery's engine. It doesen't use condensation of water at all ! Papin knew the design of Savery's pump, and he had already tested its bad sides, years before him : thermic chocks, in the reservoir, alterning cold water, then steam.

This shows the technologic advance of Papin : he had alreday aknoledged one of the major problem with steam engines : the heat conservation.

Vincent Rey, Blois, France

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This article was automatically assessed because at least one article was rated and this bot brought all the other ratings up to at least that level. BetacommandBot 03:02, 27 August 2007 (UTC)

Boyle and Papin image
I cannot see how by any stretch of the imagination that Boyle and Papin can be said to be "examining Papin's digester". Papin is looking into space, whilst Boyle appears to be vaguely looking at the strange piece of furniture to Papin's right. The digester can be clearly seen behind them on the mantlepiece, whilst other devices of Papin's invention can be discerned on the top shelf behind them, i.e. the the steam piston and what looks like a cutaway digester. Also behind them is Papin's "second engine". The drawing itself looks like a 19th Century illustration and it would be interesting to know its true source (not the website where the same lack of observation is evident).--John of Paris 13:09, 6 October 2007 (UTC)