Part 3 (1/2)
[Ill.u.s.tration: UNION-JET.
HOLLOW-TOP OR SLIT-UNION.
BATSWING.
FIG. 12.--BRAY'S ”SPECIAL” BURNERS.]
Mr. Bray's series of ”special” burners--embracing union-jet, hollow-top, and batswing--are constructed upon the principle of, and in form are somewhat similar to Bronner's burners, which have already been fully described. Apart from its being of greater bulk, the main divergence in the construction of the ”special” burner from that of the earlier ”regulator” is the introduction, into the lower part of the bra.s.s case, of a plug or washer of enamel, pierced by a small circular hole for the admission of gas into the burner; the diameter of this hole determining the quant.i.ty of gas which, at any particular pressure, is admitted into the burner. Just above the enamel washer, a layer of muslin is inserted, as in the ”regulator” burner; which, in this case, is for the purpose of subduing the agitation, or swirl, acquired by the current of gas in pa.s.sing through the narrow aperture in the washer. A tip of enamel, made of the particular description (union-jet, hollow-top, or batswing) required, fitting into the upper part of the bra.s.s case, completes the burner. The objects aimed at in the ”special” burner are to cause the gas to be consumed at the lowest pressure compatible with the maintenance of a firm flame, and with the least agitation, or swirl, in the current of gas as it issues from the burner. The former is attained, as in Bronner's burners, by diminis.h.i.+ng the area of the opening admitting into the burner, without a corresponding diminution of the orifices through which the gas issues into the atmosphere; the latter, by the interposition of the layer of muslin which is immediately above the diminis.h.i.+ng arrangement, as well as by the enlargement of the gas chamber in the upper part of the burner. The improvement thus effected in the illuminating power developed from the gas is well shown in the following tables extracted from an exhaustive series of tests of gas-burners carried out by Mr. T. Fairley, F.R.S.E., Borough a.n.a.lyst of Leeds, and embodied by him in a report presented to the Leeds Corporation. The full text of the report will be found in the _Journal of Gas Lighting_ for February 6, 1883.
_Medium Lighting Power Union-Jets._
-----------------------------------+----------------------------------- ”Regulator” Burners.
”Special” Burners.
------+------+-----+-------+-------+------+------+-----+-------+------- No.
Pres-
Cubic
Illumi-
Illumi-
No.
Pres-
Cubic
Illumi-
Illumi- of
sure
Feet
nating
nating
of
sure
Feet
nating
nating Burner
in
per
Power
Power
Burner
in
per
Power
Power
Inches
Hour
in
per 5
Inches
Hour
in
per 5
Stand.
Cubic
Stand.
Cubic
Candls.
Feet.
Candls.
Feet.
------+------+-----+-------+-------+------+------+-----+-------+------- 3
05
350
68
97
3
05
343
113
164 3
10
480
69
72
3
10
490
156
158 3
15
620
75
605
3
15
603
176
146 4
05
465
122
131
4
05
373
133
178 4
10
667
142
106
4
10
515
174
169 4
15
816
142
88
4
15
657
224
171 5
05
572
170
149
5
05
480
176
183 5
10
797
200
126
5
10
667
244
183 5
15
973
218
112
5
15
830
300
182 6
05
590
180
152
6
05
548
201
183 6
10
835
230
138
6
10
765
284
186 6
15
1060
280
132
6
15
920
342
187 ------+------+-----+-------+-------+------+------+-----+-------+-------
_Medium Lighting Power Slit-Unions._
-----------------------------------+----------------------------------- ”Regulator” Burners.
”Special” Burners.
------+------+-----+-------+-------+------+------+-----+-------+------- No.
Pres-
Cubic
Illumi-
Illumi-
No.
Pres-
Cubic
Illumi-
Illumi- of
sure
Feet
nating
nating
of
sure
Feet
nating
nating Burner
in
per
Power
Power
Burner
in
per
Power
Power
Inches
Hour
in
per 5
Inches
Hour
in
per 5
Stand.
Cubic
Stand.
Cubic
Candls.
Feet.
Candls.
Feet.
------+------+-----+-------+-------+------+------+-----+-------+------- 3
05
422
138
164
3
05
304
108
178 3
10
637
202
159
3
10
461
164
176 3
15
814
258
159
3
15
588
199
169 4
05
425
148
174
4
05
382
142
186 4
10
588
206
175
4
10
569
208
183 4
15
795
265
166
4