1026
GAS. —Gas Burners.
used was a comparatively low one, and this in allprobability prevented the air supply from beingexcessive, while at the same time the peculiar man-ner in which the gas issued insured completecombustion.
The old iron Argand was used for testing(what was then) 12-candle gas. This was after-wards improved conjointly by Letheby and SUGG,and the improved form known as the “Sugg-Letheby ” gave an increased illuminating power of2 candles with the same quality of gas, thus vir-tually raising the old 12-candle gas to 14 candles.Subsequently Sugg again made improvements inthe construction of the burner, the result of whichwas a further gain of about 2 candles in the illum-inating power ; so that what was formerly 12-candlegas, as measured by the old iron Argand, is nowregistered as equal to 16 candles by the “SuggLondon Argand.”
Fig. 16.
This burner, representedin Fig. 16, gives a powerfulwhite light and well-formedflame, differing slightly inshape from that given byordinary Argands. Thespecial points of construc-tion will be best under-stood by reference to thediagram: a is the screw-piece by which the burneris attached to the fittings.It will be seen that thereis a small conical projec-tion, b, exactly above thatpart of the burner at whichthe gas enters. When theburner is screwed firmlydown, the conical pro-jection entirely closes thegas entrance; but bygiving the burner a fewturns in the opposite direc-tion, the gas is allowed topass in proportion to theamount of unscrewing, andFI I! consequent freedom of thepassage by which the gasenters. The quantity of gaspassing to the burner maythus be easily controlled,and when the amount con-sumed is intended to be a fairly constant quantity,small paper discs may be fitted on to the screw, sothat when the burner is firmly screwed down, theconical projection, B, is still sufficiently above the gasentrance to allow the desired quantity of gas to pass.The gas passes to the burner chamber, E E, by threesmall tubes (two of which only are shown, viz., cand D, in the Fig.). The burner is surroundedby a cone of metal, G G, which helps to regulate thequantity and direction of the air supply. Thechimney, i, is supported by the lateral projections,J J, and kept in position by the spring, ir. The
burner is so constructed that the total area of thecombustion orifices is greater than that of the threetubes which admit the gas to the combustion cham-ber, and the pressure of the gas at the point of igni-tion is therefore nil. The following dimensions ofthis burner have been furnished by Sugg :—
Inch.
External diameter of steatite top,. 0-84
Diameter of centre aperture,. 0-47
Diameter of holes,. 0-04
Number of holes,. 24
This burner has been adopted by the Metropolitangas referees as the standard burner to be used fortesting the quality of the gas at the official testingstations. It is used with a 6-inch by If chimneyfor 14-candle gas, and 6 by 2 inches for gas of16-candle quality. In a later form of Sugg’s Argandthe metallic cone is perforated with a series of holesat its lower edge, which allow a distinct current ofair to circulate between the chimney and the heatedproducts of combustion. The purpose of this arrange-ment is to diminish the amount of radiant heat givenout by the burner, which in ordinary circumstancesis considerable.
The Sitter Burner .—This burner is shown inFigs. 17 and 18; Fig. 17 showing the ordinaryappearance of the burner, while Fig. 18 exhibits asectional view.
File. 17.
The principles of construction are very similar to
the London Argand of Sugg, an external conebeing used, and the pressure at the point of ignitionreduced by a suitable adjustment of the comparativeareas of the inlet and outlet holes. An essentialfeature of this form of burner, as differing fromSugg’s Argand, is that of having a central tubeor shaft, the function of which, according toValentin, is to regulate the inner air draught.Referring to the sectional diagram, it will be seenthat the gas enters at d, and passes by a series ofholes surrounding the chamber, f, into the burner