1- Collection of Carbide, Lamps and Oxyacetylene Torches, owned and restored by Ralph and Wendy Thomas
Front
row: L to R: Carbide burning in ashtray, natural raw carbide,
working Miner’s cap lamp.
Back row: L to R: Motorcycle headlamp, two Bicycle headlamps,
oxyacetylene torches and flint striker, miner’s
cap and hand lamps, carbide sales tin.
2 - Miners cap lamp, originally used in Geevor Tin Mine in Cornwall, Great Britain. These carbide lamps were phased out in 1961 and replaced by Battery cap lamps. Sensing the end of an era prompted Wendy and Ralph to collect some at that time. They demonstrate them at shows and functions run by the Machinery Preservation Club of W.A. Inc.
How
they work
Revised from Ralph Thomas’ article in Old Ploughs
and Pistons June 1995
Calcium
carbide is produced in an electric furnace at 2000°C,
and cast into ingots, which are cooled and crushed.
Quicklime + coke = calcium carbide + carbon monoxide.
Calcium carbide + water = acetylene + slaked lime (bye
product)
ACETYLENE
Acetylene was discovered in 1836, but it only started
to assume industrial importance after 1890, when a manufacturing
process for calcium carbide was found.
USES
It was first used for lighting, such as headlamps in cars,
bicycles and miner’s lamps.
The new acetylene safety lamps for miners represented
a significant improvement over some of the previous lighting
systems used in those times. However it wasn’t until
the invention of the oxyacetylene torch in 1901, which
led to the rapid development of the acetylene industry.
The oxyacetylene flame could attain temperatures up to
3100° C, which is the highest attainable for any of
the hydrocarbon gases, and is what makes this flame so
useful in welding, scarfing and cutting.
Finally in the 1930’s acetylene also became increasingly
important as a starting material for the manufacture of
organic chemicals, especially the vinyls.
MANUFACTURE
Acetylene is manufactured by several different processes.
The most familiar is by reaction of calcium carbide with
water to form the acetylene and hydrated lime. Other manufacturing
processes include thermal cracking of petroleum compounds,
partial oxidation of natural gas and passing fuel oil
through an electric arc.
PROPERTIES
Pure acetylene is odourless, however most commercial supplies
have a characteristic odour due to certain impurities.
It is not a toxic gas, but has the potential to displace
oxygen from air and for this reason it is classified as
an asphyxiant. It has anaesthetic properties and was once
used in this way under the name narcylene. There are reports
as late as 1951, where safety directions were issued for
those working in operating theatres warning of its explosive
properties.
By
Ralph Thomas - Email: rwthomas@mail2me.com.au
Photos by Wendy Thomas.