Zitate von James Watt

James Watt Foto
0  0

James Watt

Geburtstag: 19. Januar 1736
Todesdatum: 25. August 1819

Werbung

James Watt [d͡ʒe̯ɪmz wɔt] war ein schottischer Erfinder. Seine einflussreichste Erfindung war die Verbesserung des Wirkungsgrades von Dampfmaschinen durch Verlagerung des Kondensationsprozesses aus dem Zylinder in einen separaten Kondensator. Watt selbst hielt das von ihm entworfene Gestänge, das Wattsche Parallelogramm, für seine größte Erfindung. Er stattete seine Dampfmaschinen mit den vom Windmühlenbau bekannten Fliehkraftreglern zur Konstanthaltung der Drehzahl bei Belastungsschwankungen aus.

Zitate James Watt

„It now appeared that the cylinder of the model, being of brass, would conduct heat much better than the cast-iron cylinders of larger engines,“

— James Watt
Context: In the winter of 1763-4, having occasion to repair a model of Newcomen's engine belonging to the Natural Philosophy class of the University of Glasgow, my mind was again directed to it. At that period my knowledge was derived principally from Desaguliers, and partly from Belidor. I set about repairing it as a mere mechanician; and when that was done, and it was set to work, I was surprised to find that its boiler could not supply it with steam, though apparently quite large enough... By blowing the fire it was made to take a few strokes, but required an enormous quantity of injection water, though it was very lightly loaded by the column of water in the pump. It soon occurred that this was caused by the little cylinder exposing a greater surface to condense the steam, than the cylinders of larger engines did in proportion to their respective contents. It was found that by shortening the column of water in the pump, the boiler could supply the cylinder with steam, and that the engine would work regularly with a moderate quantity of injection. It now appeared that the cylinder of the model, being of brass, would conduct heat much better than the cast-iron cylinders of larger engines, (generally covered on the inside with a stony crust), and that considerable advantage could be gained by making the cylinders of some substance that would receive and give out heat slowly. Of these, wood seemed to be the most likely, provided it should prove sufficiently durable. A small engine was, therefore, constructed... made of wood, soaked in linseed oil, and baked to dryness. With this engine many experiments were made; but it was soon found that the wooden cylinder was not likely to prove durable, and that the steam condensed in filling it still exceeded the proportion of that required for large engines, according to the statements of Desaguliers. It was also found that all attempts to produce a better exhaustion by throwing in more injection, caused a disproportionate waste of steam. On reflection, the cause of this seemed to be the boiling of water in vacuo at low heats, a discovery lately made by Dr. Cullen and some other philosophers... and consequently at greater heats, the water in the cylinder would, produce a steam which would in part resist the pressure of the atmosphere.

„I proposed to remedy this defect by employing wax, tallow, or other grease, to lubricate and keep the piston tight. It next occurred to me“

— James Watt
Context: In Newcomen's engine, the piston is kept tight by water, which could not be applicable in this new method; as, if any of it entered into a partially-exhausted and hot cylinder, it would boil, and prevent the production of a vacuum, and would also cool the cylinder by its evaporation during the descent of the piston. I proposed to remedy this defect by employing wax, tallow, or other grease, to lubricate and keep the piston tight. It next occurred to me, that the mouth of the cylinder being open, the air which entered to act on the piston would cool the cylinder, and condense some steam on again filling it. I therefore proposed to put an air-tight cover upon the cylinder, with a hole and stuffing-box for the piston-rod to slide through, and to admit steam above the piston to act upon it, instead of the atmosphere.... There still remained another source of the destruction of steam, the cooling of the cylinder by the external air, which would produce an internal condensation whenever steam entered it, and which would be repeated every stroke; this I proposed to remedy by an external cylinder, containing steam, surrounded by another of wood, or of some other substance which would conduct heat slowly.

Werbung

„In Newcomen's engine, the piston is kept tight by water“

— James Watt
Context: In Newcomen's engine, the piston is kept tight by water, which could not be applicable in this new method; as, if any of it entered into a partially-exhausted and hot cylinder, it would boil, and prevent the production of a vacuum, and would also cool the cylinder by its evaporation during the descent of the piston. I proposed to remedy this defect by employing wax, tallow, or other grease, to lubricate and keep the piston tight. It next occurred to me, that the mouth of the cylinder being open, the air which entered to act on the piston would cool the cylinder, and condense some steam on again filling it. I therefore proposed to put an air-tight cover upon the cylinder, with a hole and stuffing-box for the piston-rod to slide through, and to admit steam above the piston to act upon it, instead of the atmosphere.... There still remained another source of the destruction of steam, the cooling of the cylinder by the external air, which would produce an internal condensation whenever steam entered it, and which would be repeated every stroke; this I proposed to remedy by an external cylinder, containing steam, surrounded by another of wood, or of some other substance which would conduct heat slowly.

„It is not worth my while to manufacture in three countries only; but I can find it very worthwhile to make it for the whole world.“

— James Watt
Attributed to James Watt in: Joel Mokyr, The lever of riches: Technological creativity and economic progress. Oxford University Press, 1992. p, 245

„About the year 1761, or 1762, I tried some experiments on the force of steam in a Papin's digester, and formed a species of steam-engine by fixing upon it a syringe, one-third of an inch diameter, with a solid piston, and furnished also with a cock to admit the steam from the digester, or shut it off at pleasure, as well as to open a communication from the inside of the syringe to the open air, by which the steam contained in the syringe might escape. When the communication between the digester and syringe was opened, the steam entered the syringe, and by its action upon the piston raised a considerable weight (15 lbs.) with which it was loaded. When this was raised as high as was thought proper, the communication with the digester was shut, and that with the atmosphere opened; the steam then made its escape, and the weight descended. The operations were repeated, and, though in this experiment the cock was turned by hand, it was easy to see how it could be done by the machine itself, and to make it work with perfect regularity. But I soon relinquished the idea of constructing an engine upon its principle, from being sensible it would be liable to some of the objections against Savery's engine, viz., the danger of bursting the boiler, and the difficulty of making the joints tight, and also that a great part of the power of the steam would be lost, because no vacuum was formed to assist the descent of the piston. I, however, described this engine in the fourth article of the specification of my patent of 1769; and again in the specification of another patent in the year 1784, together with a mode of applying it to the moving of wheel-carriages.“

— James Watt

„I can think of nothing else than this machine.“

— James Watt
in a letter to a friend, Dr. Lind, April 29, 1765.

Die heutige Jubiläen
Heinrich Heine Foto
Heinrich Heine86
deutscher Dichter und Publizist 1797 - 1856
Carlo Gozzi Foto
Carlo Gozzi1
Autor und Dramatiker 1720 - 1806
Friedrich Hebbel Foto
Friedrich Hebbel49
deutscher Dramatiker und Lyriker 1813 - 1863
Rudolf Wissell Foto
Rudolf Wissell1
deutscher Politiker (SPD), MdR, Reichsminister in der Wei... 1869 - 1962
Weitere 88 heute Jubiläen
Ähnliche Autoren
Nikola Tesla Foto
Nikola Tesla1
Erfinder und Physiker
Adam Smith Foto
Adam Smith6
schottischer Moralphilosoph, Aufklärer und Begründer der ...
James Clerk Maxwell Foto
James Clerk Maxwell1
schottischer Physiker
Heinz Guderian Foto
Heinz Guderian2
deutscher Offizier und Generaloberst im Zweiten Weltkrieg
Tom DeMarco3
US-amerikanischer Autor
Bud Spencer Foto
Bud Spencer5
italienischer Schauspieler
William Blake Foto
William Blake8
englischer Maler und Dichter