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The Acetylene Lamp

Forum to discuss all areas of lighthouse technology such as optics, fuels, fog signals, radiobeacons, daymarks, construction, etc.

Postby Zachary » Sun Apr 03, 2005 1:22 pm


How did this work, I understand it was the kind used in lighthouses such as Rubicon Point, CA and many HI towers with no lantern rooms?
Also, does anyone have a picture of it?
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Postby island » Sun Apr 03, 2005 6:54 pm


The most common acetylene light does not look all that different from drum lamps fueled by kerosene or containg a light bulb. The most distinctive feature is the cap on the top which is more pointed (approx. 45 degree slope) than those on the other lamps. The lens were the basic Fresnel dioptric design.

The light source was a small acetylene burner positioned at the focal point of the lens. The acetylene gas was supplied from specially designed gas cylinders. These cylinders were filled with porous mass of charcoal, diatomaceous earth and binding constituants. The cylinders were filled with about 40% by volume of acetone. Acetylene dissolves freely in acetone, the solubiliity increasing whith pressure applied. Acetylene dissolved in acetone is far less explosive under pressure than acetylene alone.
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Postby Terry_Pepper » Sun Apr 03, 2005 10:05 pm


As is the case with many inventions and scientific discoveries, there is frequently a synchronicity of knowledge which causes individuals to reach similar conclusions while separated by borders and even oceans.

As such, there are almost certainly those who would differ on its origin, however it is generally acknowledged that acetylene was first discovered by English chemist Mr. Humphrey Davy in 1836.

Acetylene is an odorless, colorless gas produced by processing calcium oxide from limestone with coke, two products which in turn react to create calcium carbide, which in turn reacts with water to form acetylene gas (C2H2.)

It was quickly discovered that when ignited, acetylene produced an intense white light, and a few attempts were undertaken to illuminate a couple of English towns with the the newly found gas. While acetylene burned considerably brighter than that produced by burning coal gas, with coal being of a seemingly endless supply throughout Europe, and being far less expensive to manufacture, store and distribute, acetylene never attained the widespread adoption for municipal lighting that coal gas enjoyed.

While it was soon identified that the intense white light produced by acetylene could serve as an excellent illuminant for lighthouses, it would have been a daunting task to supply sufficient volumes of the gas to remote lighthouses in the heavy cylinders required to keep the light burning for any reasonable length of time.

In 1901, Nils Gustaf Dalén was serving as Technical Chief of Svenska Karbid-och Acetylen AB (Swedish Carbide and Acetylene, Ltd.) when the company purchased the patent rights to a French dissolved acetylene manufacturing system. Dalén again realized the potential the bright-burning gas represented as a light source for aids to navigation if it could be equipped with some type of automatic flasher to reduce gas consumption, Dalén set about work on designing such a mechanism soon thereafter.

The mechanism Dalén designed was based on a groundbreaking principle though which the gas flow could be almost simultaneously opened and closed, enabling a small quantity of acetylene gas to provide several thousand very rapid but distinct flashes.

Bypassing the flashing mechanism with a small tube of low volume gas created a pilot, which by burning constantly could immediately ignite the gas passing through the flashing mechanism, the flow would then be almost instantaneously shut off, leaving the pilot burning and ready to ignite the next discharge of gas through the flashing mechanism.

Dalén continued his experiments over the following years, eventually designing a reliable system through which the light could be caused to emit a single intense flash of 0.03 seconds duration every 3 seconds, thereby reducing gas consumption to only 7% of that which would have been consumed by a fixed light; thereby drastically reducing the number of trips required to supply such a light with new tanks of gas to replace those expended, and allowing a light to operate virtually untended for long periods of time.

Dalén quickly came to the realization that a lighthouse outfitted with such a flashing mechanism would require little maintenance beyond the keepers turning the mechanism on at dusk and off at dawn, and determined that if he could devise a system whereby the light could automatically turn on and off at the appropriate points during the day, a light could be completely automated.

Thus he set about designing such a mechanism, which he patented in 1907, and which came to be known as the Sun Valve.

The Sun Valve was controlled by four metal rods enclosed in a glass tube, the center rod of which was blackened, while the other three were gilded and highly polished. As daylight was absorbed by the blackened rod, it heated and expanded, pressing up against a valve, and shutting off the flow of acetylene to the flasher, leaving only the dim pilot illuminated. As daylight decreased, the black rod cooled and contracted, once again opened the flow of gas through the flashing mechanism.

While subsequent improvements in his design incorporated adjustment of the duration of both flash, the eclipse and the amount of heat and cooling required to activate the Sun Valve, the 0.03 second flash followed by a 2.7 second eclipse remained a very common characteristic in lights converted over to acetylene illumination.

Such acetylene systems were installed directly in many Fresnel lenses to replace the existing oil lamps. Since the storage tanks were heavy, and the gas itself volative, the tanks were frequently stored in iron sheds attached to the exterior of the lighthouse, and the piping for the acetylene routed up unto the tower. Such a shed can be seen to the right of the tower in on of the photos in my prior posting on Fourteen Mile Point.

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A three-burner AGA acetylene system from a buoy light. The pilot tube can be seen at the right curving toward the burner tips.

Image
An AGA Sun Valve manufactured to Daléns patent. The black rod which expended and contracted to trip the valve can clearly be seen in the center of the assembly.
Last edited by Terry_Pepper on Mon Apr 04, 2005 5:47 am, edited 1 time in total.
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Postby island » Mon Apr 04, 2005 5:43 am


As a result of Dalen's work, existing lighthouses were automated and new automated lighthouses and light buoys were placed in remote inhospitable locations.

Dalen was awarded the Nobel Prize in Physics in 1912 "in recognition of his remarkable invention of automatic valves designed to be used in combination with gas accumulators in lighthouses and light-buoys." http://nobelprize.org/physics/laureates/1912/dalen-bio.html
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Postby Terry_Pepper » Tue Apr 05, 2005 9:14 pm


Zachary - Has your question been adequately answered, or are there any other questions you have on acetylene lighting systems?
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Postby mickel » Tue Apr 26, 2011 3:02 am


You need a very hot oxy-acetylene flame for silver brazing. This is the standard and best torch out there for silver brazing small things like jewelry. I have one, it gives you a pencil thin flame with excellent control.
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