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On gas burnters, gas pressure regulators and governor burners, gas globes and globe holders, and gas fixtures
408
Gerhard:
[J. F. I.,
recommends the award of the John Scott Legacy P r e m i u m and Medal to Edward G. Acheson, for his discovery of a new and valuable artificial abrasive material. Adopted at the stated m e e t i n g of the Committee on Science and the Arts, held Wednesday, F e b r u a r y 7, I894. JOSEPH M. WILSON, President. WM. H. WAHL, Secretary. Countersigned by ARTHUR BEARDSLEY, Chairman.
[Copyrighted by lke A ulhor, z894.]
ON GAS B U R ~ E R S , GAS P R E S S U R E R E G U L A T O R S AND G O V E R N O R B U R N E R S , GAS GLOBES AND GLOBE H O L D E R S , AND GAS F I X T U R E S . BY WM. PAUL G~RHARD, C.~., Consulting Engineer for Sanitary Works, New York City.
[Continued from ~. 3¢3.] II.--GAS PRESSURE REGULATORS.
It is a well-known fact that the gas pressure in the supply mains is constantly fluctuating, and that, at times and in certain districts, it is greatly in excess of what is required for proper combustion at the burners. Consumers are made aware of such excessive gas pressure by the roaring, hissing or singing gas flames, by irregularly shaped gas jets and cracked globes, by the j u m p i n g up of flames and other irregularities. It is a popular fallacy that gas companies wilfully put on a high pressure at the works in order to make the con. sumers' meters go faster. A moment's reflection ought to convince any fair-minded person that this is not the case. If the above supposition were true, the gas companies would be the losers in two ways, viz.: (I) A high pressure leads to a larger loss by leakage at the joints in the street mains, a loss usually estimated at
June, i894.]
Gas Burners, etc.
409
from seven to ten per cent. of the total gas o u t p u t , b u t often largely in exeess of this a m o u n t . (2) A n exeessive p r e s s u r e w o u l d m e a n an increased cons u m p t i o n , or r a t h e r waste, of gas in all s t r e e t l a m p s h a v i n g u n g o v e r n e d b u r n e r s and w h i c h are not supplied t h r o u g h a meter, b u t for w h i c h gas c o m p a n i e s are paid a fixed s u m p e r year. It is, nevertheless, true t h a t it is i m p r a c t i c a b l e for gas c o m p a n i e s to m a i n t a i n a c o n s t a n t pressure in the street mains. In a t o w n of small extent, w i t h a b s o l u t e l y level districts a n d w i t h centrally l o c a t e d gas works, a g a s p r e s s u r e of {~ inches of w a t e r w o u l d be a m p l e to s u p p l y all consumers. S u c h conditions, however, are q u i t e exceptional, and, as a rule, o w i n g to v a r i a t i o n s in levels of v a r i o u s districts, o w i n g to v a r i o u s d i a m e t e r s of the gas s u p p l y mains, o w i n g to t h e u n a v o i d a b l e friction in t h e pipes and t h e e x t r e m e distances to w h i c h gas has to b e c o n d u c t e d from t h e works, t h e gas w o r k s are obliged to p u t on a h i g h pressure, in order to ins u r e a sufficient s u p p l y to t h e m o s t d i s t a n t c o n s u m e r s and to t h o s e located in low-lying districts. Again, the p r e s s u r e in the h o u s e pipes and at t h e b u r n e r s c h a n g e s w i t h the v a r y i n g n u m b e r of b u r n e r s lit at one time in a dwelling, a n d also, and m u c h m o r e so, with the v a r y i n g c o n s u m p t i o n in a s t r e e t or in a district. T h e s e u n a v o i d a b l e fluctuations of p r e s s u r e r a n g e from ~-~ to }{} inches of w a t e r pressure. T h e evils of h i g h gas p r e s s u r e h a v e long b e e n recognized, and efforts m a d e to avoid the same. A n excess of p r e s s u r e at the gas b u r n e r m e a n s i m p e r f e e t c o m b u s t i o n , loss of i l l u m i n a t i n g power, v i t i a t i o n of the a t m o s p h e r e , b l o w i n g and h i s s i n g gas j e t s and a w a s t e f u l use of gas. In s p e a k i n g of burners, I h a v e a l r e a d y s t a t e d t h a t a h i g h press u r e and small b u r n e r s are n o t to be r e c o m m e n d e d ; t h a t on t h e contrary, ample v o l u m e of gas, i s s u i n g at a low pressure, from large burners, are desirable conditions for successful g a s illumination. T h e following results of experiments, t a k e n from an able p a p e r b y Mr. B u t t e r w o r t h , the general m a n a g e r of the
41o
[J. F. 1.,
Gerhard:
C o l u m b u s (O.) Gas Company, e x h i b i t clearly the evil effect of over-pressure at the b u r n e r :
Pressure ...........
con,ump.o.,u cu ,o feet per hour,
TABLE I.
TABLE I I .
C o m m o n 3-foot B u r n e r Tip.
C o m m o n 5-foot B u r n e r T i p .
~ j • •
{~]
{~ ! {~
xx~-45
I ~.... I .... I o,. i,o.-o t~ ~ ~
7"45 :6'32
Candle-power per cubic)
i 2"
2"2ot x" z
x'Sz-
"
9"70 xt'5o It3"x5
I4"2o
21"96 /23'28 2~'8o 20'28
2"~9x 2"264 2"025 1"655 1"428
T h e s e ~xperiments d e m o n s t r a t e the e n o r m o u s w a s t e of gas o c c u r r i n g w i t h c o m m o n burners, w h e r e no a t t e m p t is m a d e to r e g u l a t e the pressure. T h e y also s h o w t h a t h i g h p r e s s u r e m e a n s a loss in candle-power; for w h e r e a s t h e c o n s u m p t i o n of gas doubled, the efficiency of t h e b u r n e r d e c r e a s e d fifty-seven per cent. for the three-foot burner, and fifty-three per cent. for t h e five-foot burner, s h o w i n g a slight a d v a n t a g e in f a v o r of t h e larger burner. T h e r e are v a r i o u s w a y s in w h i c h the gas p r e s s u r e in t h e h o u s e pipes or at t h e b u r n e r s m a y be controlled and checked. One r o u g h m e t h o d consists in t h r o t t l i n g t h e m a i n g a s cock at the gas meter, and a n o t h e r in t u r n i n g t h e g a s k e y s at each fixture, i. e., at the burners. Both m e t h o d s , however, are u n s a t i s f a c t o r y and unreliable, b e c a u s e the control of p r e s s u r e is n o t a u t o m a t i c , and b e c a u s e it w o u l d obv i o u s l y be i m p r a c t i c a b l e to r e q u i r e t h e c o n s u m e r s to d e v o t e care, time and a l m o s t c o n s t a n t a t t e n t i o n to the continual a d j u s t m e n t of t h e b u r n e r keys, m a d e n e c e s s a r y b y the cons t a n t fluctuations in t h e pressure. A m u l t i t u d e of check burners h a v e b e e n devised, all h a v i n g in view a r e t a r d a t i o n of the v e l o c i t y w i t h w h i c h gas e s c a p e s at t h e burners. This t h e y accomplish to a certain extent, b u t as t h e o b s t r u c t i n g m a t e r i a l is, as a rule, fixed in t h e b u r n e r and cannot be a d j u s t e d , w h e r e a s the p r e s s u r e fluctuates constantly, it is o b v i o u s t h a t check b u r n e r s c a n n o t and do not a t t e m p t to r e g u l a t e t h e flow of g a s or g o v e r n the pressure. E v e n t h e b e s t of check burners, h a v i n g adjust-
June, t894.]
411
Gas Burners, etc.
able checks, would require a frequent adjustment during the evening hours and, therefore, would have no advantage over the simpler method of checking the flow by turning the gas keys. All that can really be said in favor of che~ck burners is that they are better than the common gas burners and that they are somewhat cheaper than automatic governor burners. T h e Empire burner, the Young America, the Broenner, Leoni and Bray burners, Sugg's " W i n s o r " burner, Gregory's mica check burner and Silber's batswing burner, having a lower chamber in which the gas expands and thus escapes at the slit of the burner tip under diminished pressure, are examples of this class. From Mr. Butterworth's paper I quote again two tests of consumption and efficiency, made with a five-foot Empire check burner and a No. 6 Bray special burner : TABLE III.
TABLE IV.
5-foot E m ,ire Check
Pressure,
.......
½~
Consumption in cubicl.
feet perhour, . . . . . . Candle-power,
. 3"1o
J-" i
C.andle-.powerpercubic'[foot, J
~ 4'o5
~ 4'85
Burner.
~ 5"50
~
No. 6 Bray Special Burner.
~
6'05 I 6"xo
9"24 12'44 x5'18 ~6"74 t8"°4 2"98z 3"°7t 3"129 3'o44 2"982
~ 7"75
~ 9 "xo xo'25 bl'w'g
x5"6° x8"56 20"74
22'7~ i - -
2"557 2'395 2"279 a'=x6
--
It is evident, from the above observations, that cheek burners do not prevent wasteful use of gas, that they do not control gas pressure and that the gas consumption of check burners necessarily varies with the pressure. In the above tests the consumption of the Empire burner was nearly doubled when the pressure increased from {~} to {~, whereas the candle-power per unit of gas consumption remained the same. While the gas works may, by using station and district governors, reduce, or control to a certain extent, the pressure in the street mains, it is obviously desirable that the consumers should use means in their houses for controlling the gas pressure automatically. Gas companies long ago recognized the evils of excessive pressure, and also the fact
4I 2
Gerhard:
[J, F. I.,
that economy in tighting depends upon its efficient control. W h e r e they undertake to f u r n i s h public illumination of streets and squares by contract with the city for a stated fixed annual sum of money for each street lamp, they therefore, applied to the burners automatic means for controlling the pressure and thus preventing waste of gas. Two entirely different methods m a y be adopted by the consumer to effect an automatic control of the gas pressure. He may apply an automatic gas governor on the house service pipe at the meter, w h i c h regulates and reduces the pressure in the whole house pipe system, or else he m a y use automatic gas governor burners, which control the volume of gas supplied to each light separately, establishing a constant Consumption at each burner, while leaving the full pressure in the house pipes. T h e r e are a large n u m b e r of gas pressure regulators in the market, and as it is the chief object of this paper to point out to the consumer that there are means available for efficient control of the gas pressure, rather than to offer a detailed description of these devices, m a n y of which are quite similar in principle and in construction, I will simply state that there are two kinds of pressure regulators, namely, the dry and the wet regulators, the former using a leather diaphragm, whereas the latter use a float, cup or bell, dipping either in glycerine or else in mercury. The Suffg diaphragm pressure regulator and Peebles' diaphragm regulator are examples of English devices of the first class, whereas the Stott, Shaw, Sugg, Bower, Ewart, Brown's " E x c e l s i o r " and Peebles' mercury, are English pressure regulators belonging to the second class. T h e " N a t i o n a l " automatic and the Amick gas regulators are American liquid governors, having a brass globe floating in a seal of glycerine, and t h e Beattie, O'Gorman and Patterson regulators are examples of American mercury seal regulators. Some of these are obtainable forsale, whereas others are only placed on rental in the houses of consumers by companies obtaining a revenue from the saving effected, as shown by t h e m o n t h l y gas bi/ls. It is an essential condition, where pressure regulators
J~ane, I894.]
Gas Burners, etc.
4I 3
are applied, t h a t the h o u s e pipes should be v e r y ample in size, t h a t there are as few e l b o w s or b e n d s in the pipes as possible, a n d t h a t the t u b i n g of g a s fixtures, the a p e r t u r e of g a s keys and t h e slits of the b u r n e r s are large ; in o t h e r words, t h a t t h e v o l u m e of g a s supplied to the b u r n e r s is ample, o t h e r w i s e t h e i n e v i t a b l e result of a control of pressure is a p a u c i t y of light. Therefore, such p r e s s u r e regulators should n e v e r be u s e d b y c o n s u m e r s w h e r e the a b o v e conditions are not complied with, o t h e r w i s e the r e m e d y m i g h t p r o v e worse than the evil complained of. It is e q u a l l y useless to a p p l y p r e s s u r e r e g u l a t o r s to h o u s e s in low-lying districts w h e r e the p r e s s u r e is already low. In all cases the s a v i n g in gas consumption, w h i c h is the result of a r e d u c t i o n in gas pressure, should be effected w i t h o u t any loss of i l l u m i n a t i n g power. A p r e s s u r e r e g u l a t o r placed on the service pipe of a h o u s e r e d u c e s an excessive g a s pressure and secures a tolerable u n i f o r m i t y of p r e s s u r e and s u p p l y at all b u r n e r s ; b u t this is only true of b u i l d i n g s with small floor area and of few stories in height. F o r large factories and halls with m a n y lights on the s a m e level, w h e r e the whole n u m b e r is a l w a y s lighted, a pressure r e g u l a t o r will answer. In the case of large b u i l d i n g s and in all b u i l d i n g s of m a n y stories, on the o t h e r hand, an a b s o l u t e l y u n i f o r m pressure is not attained, b e c a u s e no m a t t e r h o w well the d i s t r i b u t i o n pipe s y s t e m has b e e n calculated and arranged, there is necessarily s o m e loss of p r e s s u r e t h r o u g h friction in long pipes and at elbows, so t h a t t h e g a s at b u r n e r s s i t u a t e d at a distance flows at a l o w e r pressure. O w i n g to its specific gravity, w h i c h is n o t q u i t e one.half t h a t of air, gas tends to gain in p r e s s u r e with increased elevation, each rise of ten feet vertically a d d i n g one-tenth inch of w a t e r pressure. This explains why, in high buildings, even with a pressure regulator at t h e meter, the gas p r e s s u r e increases for each floor, c a u s i n g t h e b u r n e r s in u p p e r stories to " b l o w . " Therefore, the b e t t e r m e t h o d in such cases is to provide a g o v e r n o r on each floor. It is s o m e t i m e s feasible in cases w h e r e the n u m b e r of b u r n e r s l i g h t e d r e m a i n s constant, and w h e r e the pressure
414
Gerkard."
[J. F. I.,
varies o n l y slightly, to control and r e d u c e the p r e s s u r e on each floor level b y a governor, a n d in a d d i t i o n to use a good check btrrner at the fixtures. S u g g ' s " W i n s o r " screw r e g u l a t i n g b u r n e r has been devised with this special object in view. T h e best a n d s u r e s t r e m e d y , u n d o u b t e d l y , consists in the use of a u t o m a t i c a c t i n g governor burners at all fixtures. G o v e r n o r b u r n e r s m u s t not be c o n f o u n d e d w i t h cheek burners, which only retard, w h e r e a s g o v e r n o r b u r n e r s regulate, the flow of gas in such a w a y that, as the pressure increases, t h e i r r e g u l a t i n g action increases and vice versa. Such g o v e r n o r b u r n e r s cause the gas to issue at the b u r n e r in a c o n s t a n t ~'olume, no m a t t e r w h a t the pressure ifl the service pipe is, hence the n a m e " V o l u m e t r i c " b u r n e r s is s o m e t i m e s applied to t h e m . T h e first a u t o m a t i c r e g u l a t i n g b u r n e r s were devised for street lamps, and t h e y were s o m e t i m e s v e r y c l u m s y in shape, c a s t i n g large s h a d o w s downwards. T h e y h a v e been m u c h i m p r o v e d of late years, and now there are several good governor b u r n e r s o b t a i n a b l e w h i c h are c o m p a c t in shape and w h i c h act a l m o s t perfectly in r e g u l a t i n g t h e s u p p l y to t h e burners, and in p r e v e n t i n g gas from f o w i n g out u n d e r excessive pressure. E v e n g o v e r n o r burners, however, m a y in "time clog up, a n d will require occasional cleaning. T h e r e are m a n y different m a k e s of v o l u m e t r i c burners, and it is n o t m y i n t e n t i o n to describe a n y of t h e m in detail. Briefly stated, the flow of gas is controlled in t h e m b y a l i g h t cup, cone or disc, placed in an e n l a r g e d c h a m b e r of the burner, w h i c h floats up or d o w n as gas pressure increases or d i m i n i s h e s , and b e i n g c o n n e c t e d w i t h a valve at the e n t r a n c e to the burner, it opens or closes the same, and t h u s causes more gas to be a d m i t t e d w h e n the pressure fails, and w h e n the p r e s s u r e rises it reduces the supply. V o l u m e t r i c g o v e r n o r b u r n e r s are e q u a l l y applicable to far,flame, round-flame, r e g e n e r a t i v e a n d i n c a n d e s c e n t burners. T h e best r e g e n e r a t i v e lamps are a l w a y s fitted up w i t h such a regulator, and likewise are t h e A r g a n d and fiat-flame b u r n e r l a m p s of the h i g h e s t m a k e a l w a y s sold w i t h them. • A m o n g the b e s t , k n o w n g o v e r n o r b u r n e r s I m e n t i o n those
June, t894.]
Gas Burners, etc.
4I 5
of Giroud, Wilder, Sugg, P e e b l e s and Lux, the first one b e i n g a F r e n c h burner, t h e second a b u r n e r of A m e r i c a n make, the third of English, the f o u r t h of Scotch make, and t h e last one b e i n g a G e r m a n v o l u m e t r i c burner. O t h e r burners, n o t so well k n o w n or e x t e n s i v e l y used, are the R a p p l e y e r h e o m e t r i c g o v e r n o r burner, e n d o r s e d in I882 b y the C o m m i t t e e on Science and A r t s of the Franklin I n s t i t u t e ; the C h a m p i o n burner, p a t e n t e d b y V a n W i e s in I89o; the Chamberlain, Boore and J a c k s o n burners, all of A m e r i c a n m a k e ; t h e S c h u e l k e a d j u s t a b l e gas g o v e r n o r burner, of G e r m a n make, and the Orme, H a w k i n s and A c m e burners, of English make, the H a w k i n s b u r n e r b e i n g the only g o v e r n o r b u r n e r w i t h union j e t tip k n o w n to me. My list does not p r e t e n d to b e exhaustive, and it is quite possible t h a t I m a y h a v e u n i n t e n t i o n a l l y o m i t t e d some good b u r n e r s w h i c h h a v e n o t come to m y notice. T h e W i l d e r v o l u m e t r i c g o v e r n o r b u r n e r is the invention of Moses G. Wilder, M.E., of Philadelphia, w h o o b t a i n e d a p a t e n t for it in 188o. T h i s b u r n e r is a good example of an A m e r i c a n g o v e r n o r burner, and it is suitable not only for flat-flame and A r g a n d burners, b u t also for r e g e n e r a t i v e l a m p s and for the W e l s b a c h i n c a n d e s c e n t light. T h e maker, in d e s c r i b i n g it, states that it is not a pressure r e d u c e r or regulator, t h a t the flow of gas t h r o u g h it is not c h a n g e d b y v e r y wide variations of pressure, and that it secures a uniform rate of s u p p l y to the burner, with little or no reduction of pressure. T h e i n v e n t o r of the Boore burner, Mr. Lewis Boore, of Buffalo, N. Y., states that he e n d e a v o r e d to p r o d u c e a reliable and simple a u t o m a t i c g o v e r n o r b u r n e r of low cost, w h i c h w o u l d indicate practically correctly for a v e r y wide r a n g e of pressure, w i t h o u t h a v i n g such an e x t r e m e accur a c y or such close a d j u s t m e n t as to d e s t r o y its utility. W m . S u g g & Co. m a k e t w o kinds of v o l u m e t r i c burners, a steatite float g o v e r n o r and a leather d i a p h r a g m g o v e r n o r burner. Sugg's patent "Alexandra" governor burners combine g r e a t e c o n o m y with efficiency, and p r o d u c e a brilliant, white, silent light. T h e y are fitted with steatite float governor,
416
[J. F. I.,
Gerhard:
and the superior light attained is also a result of adopting double annealed Albatrine globes with wide opening. A n even better flat-flame burner by the s a m e maker is Sugg's patent "Christiania" governor burner, fitted with a specially prepared leather diaphragm governor, with Sugg's patent table top circular slit steatite b u r n e r tip. Sugg's London improved A r g a n d burner always has a governor b u r n e r attached to the fixture. Mr. Wilder calls attention to the fact that his governor burner, to operate well, requires a full street pressure. This rule is applicable to all volumetric burners ; hence, where these are used, a pressure regulator should not be used at the meter. * In order to show, by actual experiments, how nearly uniform the consumption of gas remains with governor burners, I refer the reader again to Mr. Butterworth's able paper on governor burners, wherein is published the following table, showing the gas consumption of a n u m b e r of such burners under varying pressures : TABI,~ V.
Pressure, .
{~
. . . . . . . . .
CU, f l .
Six-foot governor burner, . Six-foot governor burner, . Five-foot governor burner, Five-foot governor burner, Five-foot governor burner, Adjustable burner, ..... Adjustable burner, ..... Adjustable burner, • ....
. . • • •
p e r hr. 6"20
5"95 4"50 4"5o ,4"9o 5"60 4"96 4"95
15 IT cu. f t . cu. fe. cu. . cu. f t . ft. .it. p e r hr. p e r lzr. p e r ~rr• # e r hr. #cu. e r hr. pcu. e r hr.
6'20 6"5 ° 4'50 4"65 4"95 5"50 5"97 4"95
6"35 6"20 4"55 4"55 4"95 5 "40 6"21 4"95
6'30 6"20 4"55 4"65 4'95 5"30 6"19 4"95
6"25 6"05 4"65 4"70 4"9 o 5"O7 6"05 4"95
6 '25 6"15 4"65 4"65 4"9° 4"80 5"89 4"95
6"4C~ 6"05 4"60 4"55 4"90 4"60 569 4"95
T h e last burner in the table showed a perfect uniformity of supply under the wide range of pressures used in the test. Some of these governor burners are adjustable, and if they are required to pass a certain q u a n t i t y of gas per hour, a nice a d j u s t m e n t is necessary, which can only be accomplished if the candle power and quality of gas, its pressure and specific gravity are known. A governor burner adjusted for a gas of certain specific gravity would not remain correct for a gas of different density, or for a n y temperature which would change the density.
June, t894.]
Gas Burners, etc.
4x 7
Both, t h e p r e s s u r e r e g u l a t o r s on t h e m a i n service pipe and the g o v e r n o r burners, accomplish a s a v i n g in gas cons u m p t i o n b y p r e v e n t i n g useless waste, a m o u n t i n g to a r e d u c t i o n of from t w e n t y to forty per cent. in the gas bills. O t h e r incidental a d v a n t a g e s g a i n e d are: a g r e a t improvem e n t in t h e steadiness of a gas flame w i t h o u t r e g a r d to the n u m b e r of b u r n e r s lit or t h e c o n s t a n t l y c h a n g i n g street pressure ; t h e h i s s i n g or r o a r i n g noise, the blowing, and the flickering of lights is p r e v e n t e d ; the illumination b e c o m e s s t r o n g e r ; t h e s m o k i n g of A r g a n d b u r n e r s is p r e v e n t e d , and the air of the room is v i t i a t e d to a m u c h smaller e x t e n t b y the p r o d u c t s of i m p e r f e c t c o m b u s t i o n . With governor burners, however, t h e s e results are a t t a i n e d in a h i g h e r degree than w i t h p r e s s u r e r e g u l a t o r s on the service pipe. T o s u m up, practical considerations m u s t decide w h i c h form of r e g u l a t i o n it is b e s t to adopt. In this connection the following rules are to be r e c o m m e n d e d , viz. : (a) W h e r e the street m a i n s are large and the differences of level insignificant, use either check b u r n e r s or volumetric burners. (b) W h e r e t h e street m a i n s are small, or the p r e s s u r e is low or the h o u s e pipe insufficient, n e i t h e r m e t h o d of regulation should be employed. (c) W h e r e the t o w n is hilly and there are considerable differences of elevation in the districts, a p r e s s u r e r e g u l a t o r will answer, p r o v i d e d the h o u s e pipes are large, the gas keys full bore, and t h e b u i l d i n g only a few stories in height, and not of g r e a t e x t e n t laterally. (d) W h e r e in such districts the b u i l d i n g s are high or v e r y large, a pressure r e g u l a t o r on each floor should be used, t o g e t h e r w i t h r e g u l a t i n g check b u r n e r s at the fixtures, b u t in such cases g o v e r n o r b u r n e r s are a simpler remedy, and are, therefore, to be preferred. I I I . - - G L A S S GLOBES A N D GLOBE H O L D E R S .
Flat-flame b u r n e r s are, as a rule, s u r r o u n d e d with glass globes, and practical experience and o b s e r v a t i o n have e s t a b l i s h e d the fact t h a t if these are u n s u i t a b l y arranged or of i m p r o p e r shape, t h e y c o n s t i t u t e a n o t h e r factor, causVoL. CXXXVII 27
418
Gerhard."
[J.F.L,
in K deficient illumination, i m p e r f e c t combustion, and freq u e n t l y a w a s t e of gas and a c o r r e s p o n d i n g increase in the gas bills. Gas globes are used chiefly to p r o t e c t open flames a g a i n s t d r a u g h t , and t h e r e b y to p r e v g n t the a n n o y i n g u n s t e a d i n e s s and flickering of lights. T h e y are also e m p l o y e d to s h a d e the eyes from the direct glare of t h e light, to diffuse and soften the light, also to add to the good external a p p e a r a n c e of gas fixtures ; and finally, gas globes are, for safety's sake, placed over n a k e d lights to shield the flame from c o m i n g into direct c o n t a c t with i n f l a m m a b l e materials. F r o m all of w h i c h it follows that gas globes are used for u t i l i t y even more than for ornament, hence their design and construction should be b a s e d on sound principles. In order to Obtain g o o d illumination, and to avoid the flickering of gas lights, the air n e c e s s a r y for c o m b u s t i o n should be b r o u g h t to the flame in a slow, u n i f o r m and s t e a d y current. If the air s u p p l y is insufficient a flame is apt to s m o k e and will blacken ceilings and c o n t a m i n a t e t h e air. If the air r u s h e s to the flame in a violent manner, this will d e s t r o y the s t e a d i n e s s of the light, the light will flicker and j u m p , and it has the f u r t h e r d e t r i m e n t a l effect of cooling the flame, and t h e r e b y r e d u c i n g its brilliancy. T h e old style glass g l o b e s were q u i t e defective in shape, form and material. T h e y were m a d e w i t h v e r y narrow top and b o t t o m openings, or if tulip-shaped and w i d e n i n g at the top, the b o t t o m o p e n i n g was e x t r e m e l y narrow, b e i n g often b u t one and one-half or two inches in diameter, and, w h e r e such globes were in use, the ceiling was often the only welli l l u m i n a t e d place. Tile result was that, o w i n g to the smallness of the b o t t o m aperture, the c o n t r a c t e d g l o b e acted like a chimney, c a u s i n g the air c u r r e n t to i m p i n g e upon the flame to such an e x t e n t as to seriously d i s t u r b the flame, and t h e r e b y c a u s i n g s a m e to flicker in a d i s t r e s s i n g manner. A n o t h e r defect of the old style globes is that t h e y form d u s t traps, and t h a t t h e y are readily soiled in lighting. rf, a d d e d to this defect in the globes, the g a s p r e s s u r e at the b u r n e r was excessive, t h e r e s u l t i n g i l l u m i n a t i o n necessarily was v e r y imperfect. To d e t e r m i n e the actual loss of
June. I894.]
Gas Burners, etc.
4I 9
l i g h t due to small o p e n i n g s in globes, Dr. W a l l a c e made a series of experiments, which showed t h e following results : A n a k e d flame was tested a n d f o u n d to g i v e I6"8 candle light. T h e same flame, s u r r o u n d e d w i t h a seven and one-half inch d i a m e t e r clear globe, w i t h two and t h r e e - e i g h t h inch b o t t o m opening, gave I5"4 candle lights, or loss of 8"3 per cent. T h e s a m e flame, s u r r o u n d e d with a seven and one-half inch d i a m e t e r clear globe, w i t h two and one-quarter b o t t o m o p e n i n g gave 15"2 candle light, or loss of 9"5 per cent. T h e same flame, s u r r o u n d e d w i t h a seven and one.half inch d i a m e t e r clear globe, w i t h two inch b o t t o m opening, gave I3"6 candle light, or loss of n i n e t e e n per cent. T h e same flame, s ~ r r o u n d e d w i t h a seven and one.half inch d i a m e t e r clear globe, w i t h one and one-half inch b o t t o m o p e n i n g gave I3" candle light, or loss of t w e n t y - t w o per cent. T h e same flame, s u r r o u n d e d w i t h a seven and one-half inch d i a m e t e r clear globe, w i t h one inch b o t t o m opening, gave I2" candle light, or loss of 28"6 per cent. All glass globes, moreover, absorb a certain a m o u n t of light, and t h e l o s s of l i g h t a n d c o r r e s p o n d i n g waste of gas d u e to this cause increases the more opaque the glass globe is. F a n c y " r u b y " or o t h e r colored, etched or otherwise decorated globes in p a r t i c u l a r o b s t r u c t a large a m o u n t of light, and hence increase gas bills b y the necessity of keepi n g a l a r g e r n u m b e r of l i g h t s b u r n i n g on a chandelier. It is s t a t e d on,good a u t h o r i t y t h a t l i g h t is o b s t r u c t e d as follows: F e r cenl.
By clear glass globes, . . . . . . . . . . . . . . . . . . . IO'I5 By slightly ground globes, . . . . . . . . . . . . . . . . 24 By globes ground all over, . . . . . . . . . . . . . . . . . 25"4o By opal thick glass globes, . . . . . . . . . . . . . . . . . 35'6o By colored or painted globes, . . . . . . . . . . . . . . . . 64 L a s t l y , the globes w i t h n a r r o w b o t t o m and wide top o p e n i n g are objectionable, because i n s t e a d of c a s t i n g l i g h t o u t w a r d and d o w n w a r d by reflection, t h e y throw the greatest a m o u n t of l i g h t up to the ceiling, where it is not wanted. I t m a t t e r s little how a t t r a c t i v e in shape and artistic in o u t l i n e such old style globes are; as long as t h e y tend to d i s t u r b the flame t h e y are clearly objectionable. These d e f e c t s h a v e been g r a d u a l l y recognized, and such globes
420
Gerhard.
[ J. F. I.,
with contracted openings happily are now being discarded. The new form of globes has wide bottom openings, which admit the air without causing a draft; the shape of the globe is designed more with a due regard to its proper functions than solely from a decorative point of view. Such globes induce a straight, upward, gentle current of air, and the flame remains steady and bright. All globes of modern construction have bottom openings four and five inches in diameter, and have the incidental advantage that a portion of the light falls directly downward without being obstructed. The Sugg "Alez~andra" and " C h r i s t i a n i a " burners are surrounded with globes of most desirable shape and material; the Broenner burners have similarly shaped " Cornelian" globes; and Wilder, in the description of his volumetric burner, recommends globes four and one-half inches in diameter at the bottom and five and one-half inches at the top. R e g a r d i n g the material for globes, clear crystal glass is the best, because it absorbs the least light. Still, it oftentimes becomes desirable to render the light of a gas flame soft and mellow, and f ~ r such cases thin milk-white opal globes are best and quit~ effective. Sugg uses with h i s b e s t fiat flame governor burners double annealed large size globes, with wide bottom opening, which he calls " Albatrine " globes, and which give a particular softness to the light. The cheaper kind of thick opaque white glass globes should be avoided, as they intercept as much as seventy to eighty per cent. of light. In connection with globes, it is noteworthy that somewhat increased illumination is obtained by using globe holders which are as little light obstructing as possible, i.e., very thin sheet brass or brass wire globe holders. T h e old style fixtures had h e a v y and cumbrous cast brass holders, or heavy discs, triangles or rings, all of which are objectionable, because they intercept a portion of the light, and cast a shadow downward and thereby cause a loss of light. T h e new shadowless globe holders, made of three simple prongs of brass wire, not more than one-eighth of an inch thick, and
June, I894..]
Emery and other Abrasives.
42!
without any rims whatever, are r e c o m m e n d e d by all dealers in advanced gas light fixtures. Lastly, the position of the glass globe in reference to the gas flame is of a good deal of importance where it is desired t o secure a steady, bright light. It has been found long ago, by experiment, that by arranging a shadowless globe holder on the burner in such a m a n n e r as to place the level of the bottom of the flame in line with the bottom edge of the globe, the flame will burn very quietly and steadily, and will not be affected much, if any, by the ascending air current, whereas if the flame is set higher it is apt to flicker. This correct position and shape of a glass globe has been pointed out repeatedly by such gas engineers as Wilder, Peebles, Sugg, Broenner, Silber and others, in connection with their gas burning appliances; but on the whole, in practice, little attention has been paid to this simple yet efficient rule. [ To be concluded.]
E M E R Y AND O T H E R A B R A S I V E S . ~ BY T. DUNKIN PARET, President of t h e Tanite Company.
[ Concluded from p. 372.]
While small specimens of corundum, in the form of imperfect sapphires, have come from Montana, where the existence of this mineral has long been known, no other locality has yielded corundum except that well-known belt which reaches from Massachusetts to Georgia, and which seems to have its center in the corner where North and South Carolina, Georgia and Tennessee come together. In this belt the localities where corundum occurs are innumerable, but the prevalence of the mineral is a poor indication of its quantity. Corundum occurs in pockets, seams, sand veins, narrow streaks and detached crystals, seldom in large mass. Chester County, Pa., is, apparently, the only locality where large solid masses have been found. The
Gerhard:
[J. F. I.,
recommends the award of the John Scott Legacy P r e m i u m and Medal to Edward G. Acheson, for his discovery of a new and valuable artificial abrasive material. Adopted at the stated m e e t i n g of the Committee on Science and the Arts, held Wednesday, F e b r u a r y 7, I894. JOSEPH M. WILSON, President. WM. H. WAHL, Secretary. Countersigned by ARTHUR BEARDSLEY, Chairman.
[Copyrighted by lke A ulhor, z894.]
ON GAS B U R ~ E R S , GAS P R E S S U R E R E G U L A T O R S AND G O V E R N O R B U R N E R S , GAS GLOBES AND GLOBE H O L D E R S , AND GAS F I X T U R E S . BY WM. PAUL G~RHARD, C.~., Consulting Engineer for Sanitary Works, New York City.
[Continued from ~. 3¢3.] II.--GAS PRESSURE REGULATORS.
It is a well-known fact that the gas pressure in the supply mains is constantly fluctuating, and that, at times and in certain districts, it is greatly in excess of what is required for proper combustion at the burners. Consumers are made aware of such excessive gas pressure by the roaring, hissing or singing gas flames, by irregularly shaped gas jets and cracked globes, by the j u m p i n g up of flames and other irregularities. It is a popular fallacy that gas companies wilfully put on a high pressure at the works in order to make the con. sumers' meters go faster. A moment's reflection ought to convince any fair-minded person that this is not the case. If the above supposition were true, the gas companies would be the losers in two ways, viz.: (I) A high pressure leads to a larger loss by leakage at the joints in the street mains, a loss usually estimated at
June, i894.]
Gas Burners, etc.
409
from seven to ten per cent. of the total gas o u t p u t , b u t often largely in exeess of this a m o u n t . (2) A n exeessive p r e s s u r e w o u l d m e a n an increased cons u m p t i o n , or r a t h e r waste, of gas in all s t r e e t l a m p s h a v i n g u n g o v e r n e d b u r n e r s and w h i c h are not supplied t h r o u g h a meter, b u t for w h i c h gas c o m p a n i e s are paid a fixed s u m p e r year. It is, nevertheless, true t h a t it is i m p r a c t i c a b l e for gas c o m p a n i e s to m a i n t a i n a c o n s t a n t pressure in the street mains. In a t o w n of small extent, w i t h a b s o l u t e l y level districts a n d w i t h centrally l o c a t e d gas works, a g a s p r e s s u r e of {~ inches of w a t e r w o u l d be a m p l e to s u p p l y all consumers. S u c h conditions, however, are q u i t e exceptional, and, as a rule, o w i n g to v a r i a t i o n s in levels of v a r i o u s districts, o w i n g to v a r i o u s d i a m e t e r s of the gas s u p p l y mains, o w i n g to t h e u n a v o i d a b l e friction in t h e pipes and t h e e x t r e m e distances to w h i c h gas has to b e c o n d u c t e d from t h e works, t h e gas w o r k s are obliged to p u t on a h i g h pressure, in order to ins u r e a sufficient s u p p l y to t h e m o s t d i s t a n t c o n s u m e r s and to t h o s e located in low-lying districts. Again, the p r e s s u r e in the h o u s e pipes and at t h e b u r n e r s c h a n g e s w i t h the v a r y i n g n u m b e r of b u r n e r s lit at one time in a dwelling, a n d also, and m u c h m o r e so, with the v a r y i n g c o n s u m p t i o n in a s t r e e t or in a district. T h e s e u n a v o i d a b l e fluctuations of p r e s s u r e r a n g e from ~-~ to }{} inches of w a t e r pressure. T h e evils of h i g h gas p r e s s u r e h a v e long b e e n recognized, and efforts m a d e to avoid the same. A n excess of p r e s s u r e at the gas b u r n e r m e a n s i m p e r f e e t c o m b u s t i o n , loss of i l l u m i n a t i n g power, v i t i a t i o n of the a t m o s p h e r e , b l o w i n g and h i s s i n g gas j e t s and a w a s t e f u l use of gas. In s p e a k i n g of burners, I h a v e a l r e a d y s t a t e d t h a t a h i g h press u r e and small b u r n e r s are n o t to be r e c o m m e n d e d ; t h a t on t h e contrary, ample v o l u m e of gas, i s s u i n g at a low pressure, from large burners, are desirable conditions for successful g a s illumination. T h e following results of experiments, t a k e n from an able p a p e r b y Mr. B u t t e r w o r t h , the general m a n a g e r of the
41o
[J. F. 1.,
Gerhard:
C o l u m b u s (O.) Gas Company, e x h i b i t clearly the evil effect of over-pressure at the b u r n e r :
Pressure ...........
con,ump.o.,u cu ,o feet per hour,
TABLE I.
TABLE I I .
C o m m o n 3-foot B u r n e r Tip.
C o m m o n 5-foot B u r n e r T i p .
~ j • •
{~]
{~ ! {~
xx~-45
I ~.... I .... I o,. i,o.-o t~ ~ ~
7"45 :6'32
Candle-power per cubic)
i 2"
2"2ot x" z
x'Sz-
"
9"70 xt'5o It3"x5
I4"2o
21"96 /23'28 2~'8o 20'28
2"~9x 2"264 2"025 1"655 1"428
T h e s e ~xperiments d e m o n s t r a t e the e n o r m o u s w a s t e of gas o c c u r r i n g w i t h c o m m o n burners, w h e r e no a t t e m p t is m a d e to r e g u l a t e the pressure. T h e y also s h o w t h a t h i g h p r e s s u r e m e a n s a loss in candle-power; for w h e r e a s t h e c o n s u m p t i o n of gas doubled, the efficiency of t h e b u r n e r d e c r e a s e d fifty-seven per cent. for the three-foot burner, and fifty-three per cent. for t h e five-foot burner, s h o w i n g a slight a d v a n t a g e in f a v o r of t h e larger burner. T h e r e are v a r i o u s w a y s in w h i c h the gas p r e s s u r e in t h e h o u s e pipes or at t h e b u r n e r s m a y be controlled and checked. One r o u g h m e t h o d consists in t h r o t t l i n g t h e m a i n g a s cock at the gas meter, and a n o t h e r in t u r n i n g t h e g a s k e y s at each fixture, i. e., at the burners. Both m e t h o d s , however, are u n s a t i s f a c t o r y and unreliable, b e c a u s e the control of p r e s s u r e is n o t a u t o m a t i c , and b e c a u s e it w o u l d obv i o u s l y be i m p r a c t i c a b l e to r e q u i r e t h e c o n s u m e r s to d e v o t e care, time and a l m o s t c o n s t a n t a t t e n t i o n to the continual a d j u s t m e n t of t h e b u r n e r keys, m a d e n e c e s s a r y b y the cons t a n t fluctuations in t h e pressure. A m u l t i t u d e of check burners h a v e b e e n devised, all h a v i n g in view a r e t a r d a t i o n of the v e l o c i t y w i t h w h i c h gas e s c a p e s at t h e burners. This t h e y accomplish to a certain extent, b u t as t h e o b s t r u c t i n g m a t e r i a l is, as a rule, fixed in t h e b u r n e r and cannot be a d j u s t e d , w h e r e a s the p r e s s u r e fluctuates constantly, it is o b v i o u s t h a t check b u r n e r s c a n n o t and do not a t t e m p t to r e g u l a t e t h e flow of g a s or g o v e r n the pressure. E v e n t h e b e s t of check burners, h a v i n g adjust-
June, t894.]
411
Gas Burners, etc.
able checks, would require a frequent adjustment during the evening hours and, therefore, would have no advantage over the simpler method of checking the flow by turning the gas keys. All that can really be said in favor of che~ck burners is that they are better than the common gas burners and that they are somewhat cheaper than automatic governor burners. T h e Empire burner, the Young America, the Broenner, Leoni and Bray burners, Sugg's " W i n s o r " burner, Gregory's mica check burner and Silber's batswing burner, having a lower chamber in which the gas expands and thus escapes at the slit of the burner tip under diminished pressure, are examples of this class. From Mr. Butterworth's paper I quote again two tests of consumption and efficiency, made with a five-foot Empire check burner and a No. 6 Bray special burner : TABLE III.
TABLE IV.
5-foot E m ,ire Check
Pressure,
.......
½~
Consumption in cubicl.
feet perhour, . . . . . . Candle-power,
. 3"1o
J-" i
C.andle-.powerpercubic'[foot, J
~ 4'o5
~ 4'85
Burner.
~ 5"50
~
No. 6 Bray Special Burner.
~
6'05 I 6"xo
9"24 12'44 x5'18 ~6"74 t8"°4 2"98z 3"°7t 3"129 3'o44 2"982
~ 7"75
~ 9 "xo xo'25 bl'w'g
x5"6° x8"56 20"74
22'7~ i - -
2"557 2'395 2"279 a'=x6
--
It is evident, from the above observations, that cheek burners do not prevent wasteful use of gas, that they do not control gas pressure and that the gas consumption of check burners necessarily varies with the pressure. In the above tests the consumption of the Empire burner was nearly doubled when the pressure increased from {~} to {~, whereas the candle-power per unit of gas consumption remained the same. While the gas works may, by using station and district governors, reduce, or control to a certain extent, the pressure in the street mains, it is obviously desirable that the consumers should use means in their houses for controlling the gas pressure automatically. Gas companies long ago recognized the evils of excessive pressure, and also the fact
4I 2
Gerhard:
[J, F. I.,
that economy in tighting depends upon its efficient control. W h e r e they undertake to f u r n i s h public illumination of streets and squares by contract with the city for a stated fixed annual sum of money for each street lamp, they therefore, applied to the burners automatic means for controlling the pressure and thus preventing waste of gas. Two entirely different methods m a y be adopted by the consumer to effect an automatic control of the gas pressure. He may apply an automatic gas governor on the house service pipe at the meter, w h i c h regulates and reduces the pressure in the whole house pipe system, or else he m a y use automatic gas governor burners, which control the volume of gas supplied to each light separately, establishing a constant Consumption at each burner, while leaving the full pressure in the house pipes. T h e r e are a large n u m b e r of gas pressure regulators in the market, and as it is the chief object of this paper to point out to the consumer that there are means available for efficient control of the gas pressure, rather than to offer a detailed description of these devices, m a n y of which are quite similar in principle and in construction, I will simply state that there are two kinds of pressure regulators, namely, the dry and the wet regulators, the former using a leather diaphragm, whereas the latter use a float, cup or bell, dipping either in glycerine or else in mercury. The Suffg diaphragm pressure regulator and Peebles' diaphragm regulator are examples of English devices of the first class, whereas the Stott, Shaw, Sugg, Bower, Ewart, Brown's " E x c e l s i o r " and Peebles' mercury, are English pressure regulators belonging to the second class. T h e " N a t i o n a l " automatic and the Amick gas regulators are American liquid governors, having a brass globe floating in a seal of glycerine, and t h e Beattie, O'Gorman and Patterson regulators are examples of American mercury seal regulators. Some of these are obtainable forsale, whereas others are only placed on rental in the houses of consumers by companies obtaining a revenue from the saving effected, as shown by t h e m o n t h l y gas bi/ls. It is an essential condition, where pressure regulators
J~ane, I894.]
Gas Burners, etc.
4I 3
are applied, t h a t the h o u s e pipes should be v e r y ample in size, t h a t there are as few e l b o w s or b e n d s in the pipes as possible, a n d t h a t the t u b i n g of g a s fixtures, the a p e r t u r e of g a s keys and t h e slits of the b u r n e r s are large ; in o t h e r words, t h a t t h e v o l u m e of g a s supplied to the b u r n e r s is ample, o t h e r w i s e t h e i n e v i t a b l e result of a control of pressure is a p a u c i t y of light. Therefore, such p r e s s u r e regulators should n e v e r be u s e d b y c o n s u m e r s w h e r e the a b o v e conditions are not complied with, o t h e r w i s e the r e m e d y m i g h t p r o v e worse than the evil complained of. It is e q u a l l y useless to a p p l y p r e s s u r e r e g u l a t o r s to h o u s e s in low-lying districts w h e r e the p r e s s u r e is already low. In all cases the s a v i n g in gas consumption, w h i c h is the result of a r e d u c t i o n in gas pressure, should be effected w i t h o u t any loss of i l l u m i n a t i n g power. A p r e s s u r e r e g u l a t o r placed on the service pipe of a h o u s e r e d u c e s an excessive g a s pressure and secures a tolerable u n i f o r m i t y of p r e s s u r e and s u p p l y at all b u r n e r s ; b u t this is only true of b u i l d i n g s with small floor area and of few stories in height. F o r large factories and halls with m a n y lights on the s a m e level, w h e r e the whole n u m b e r is a l w a y s lighted, a pressure r e g u l a t o r will answer. In the case of large b u i l d i n g s and in all b u i l d i n g s of m a n y stories, on the o t h e r hand, an a b s o l u t e l y u n i f o r m pressure is not attained, b e c a u s e no m a t t e r h o w well the d i s t r i b u t i o n pipe s y s t e m has b e e n calculated and arranged, there is necessarily s o m e loss of p r e s s u r e t h r o u g h friction in long pipes and at elbows, so t h a t t h e g a s at b u r n e r s s i t u a t e d at a distance flows at a l o w e r pressure. O w i n g to its specific gravity, w h i c h is n o t q u i t e one.half t h a t of air, gas tends to gain in p r e s s u r e with increased elevation, each rise of ten feet vertically a d d i n g one-tenth inch of w a t e r pressure. This explains why, in high buildings, even with a pressure regulator at t h e meter, the gas p r e s s u r e increases for each floor, c a u s i n g t h e b u r n e r s in u p p e r stories to " b l o w . " Therefore, the b e t t e r m e t h o d in such cases is to provide a g o v e r n o r on each floor. It is s o m e t i m e s feasible in cases w h e r e the n u m b e r of b u r n e r s l i g h t e d r e m a i n s constant, and w h e r e the pressure
414
Gerkard."
[J. F. I.,
varies o n l y slightly, to control and r e d u c e the p r e s s u r e on each floor level b y a governor, a n d in a d d i t i o n to use a good check btrrner at the fixtures. S u g g ' s " W i n s o r " screw r e g u l a t i n g b u r n e r has been devised with this special object in view. T h e best a n d s u r e s t r e m e d y , u n d o u b t e d l y , consists in the use of a u t o m a t i c a c t i n g governor burners at all fixtures. G o v e r n o r b u r n e r s m u s t not be c o n f o u n d e d w i t h cheek burners, which only retard, w h e r e a s g o v e r n o r b u r n e r s regulate, the flow of gas in such a w a y that, as the pressure increases, t h e i r r e g u l a t i n g action increases and vice versa. Such g o v e r n o r b u r n e r s cause the gas to issue at the b u r n e r in a c o n s t a n t ~'olume, no m a t t e r w h a t the pressure ifl the service pipe is, hence the n a m e " V o l u m e t r i c " b u r n e r s is s o m e t i m e s applied to t h e m . T h e first a u t o m a t i c r e g u l a t i n g b u r n e r s were devised for street lamps, and t h e y were s o m e t i m e s v e r y c l u m s y in shape, c a s t i n g large s h a d o w s downwards. T h e y h a v e been m u c h i m p r o v e d of late years, and now there are several good governor b u r n e r s o b t a i n a b l e w h i c h are c o m p a c t in shape and w h i c h act a l m o s t perfectly in r e g u l a t i n g t h e s u p p l y to t h e burners, and in p r e v e n t i n g gas from f o w i n g out u n d e r excessive pressure. E v e n g o v e r n o r burners, however, m a y in "time clog up, a n d will require occasional cleaning. T h e r e are m a n y different m a k e s of v o l u m e t r i c burners, and it is n o t m y i n t e n t i o n to describe a n y of t h e m in detail. Briefly stated, the flow of gas is controlled in t h e m b y a l i g h t cup, cone or disc, placed in an e n l a r g e d c h a m b e r of the burner, w h i c h floats up or d o w n as gas pressure increases or d i m i n i s h e s , and b e i n g c o n n e c t e d w i t h a valve at the e n t r a n c e to the burner, it opens or closes the same, and t h u s causes more gas to be a d m i t t e d w h e n the pressure fails, and w h e n the p r e s s u r e rises it reduces the supply. V o l u m e t r i c g o v e r n o r b u r n e r s are e q u a l l y applicable to far,flame, round-flame, r e g e n e r a t i v e a n d i n c a n d e s c e n t burners. T h e best r e g e n e r a t i v e lamps are a l w a y s fitted up w i t h such a regulator, and likewise are t h e A r g a n d and fiat-flame b u r n e r l a m p s of the h i g h e s t m a k e a l w a y s sold w i t h them. • A m o n g the b e s t , k n o w n g o v e r n o r b u r n e r s I m e n t i o n those
June, t894.]
Gas Burners, etc.
4I 5
of Giroud, Wilder, Sugg, P e e b l e s and Lux, the first one b e i n g a F r e n c h burner, t h e second a b u r n e r of A m e r i c a n make, the third of English, the f o u r t h of Scotch make, and t h e last one b e i n g a G e r m a n v o l u m e t r i c burner. O t h e r burners, n o t so well k n o w n or e x t e n s i v e l y used, are the R a p p l e y e r h e o m e t r i c g o v e r n o r burner, e n d o r s e d in I882 b y the C o m m i t t e e on Science and A r t s of the Franklin I n s t i t u t e ; the C h a m p i o n burner, p a t e n t e d b y V a n W i e s in I89o; the Chamberlain, Boore and J a c k s o n burners, all of A m e r i c a n m a k e ; t h e S c h u e l k e a d j u s t a b l e gas g o v e r n o r burner, of G e r m a n make, and the Orme, H a w k i n s and A c m e burners, of English make, the H a w k i n s b u r n e r b e i n g the only g o v e r n o r b u r n e r w i t h union j e t tip k n o w n to me. My list does not p r e t e n d to b e exhaustive, and it is quite possible t h a t I m a y h a v e u n i n t e n t i o n a l l y o m i t t e d some good b u r n e r s w h i c h h a v e n o t come to m y notice. T h e W i l d e r v o l u m e t r i c g o v e r n o r b u r n e r is the invention of Moses G. Wilder, M.E., of Philadelphia, w h o o b t a i n e d a p a t e n t for it in 188o. T h i s b u r n e r is a good example of an A m e r i c a n g o v e r n o r burner, and it is suitable not only for flat-flame and A r g a n d burners, b u t also for r e g e n e r a t i v e l a m p s and for the W e l s b a c h i n c a n d e s c e n t light. T h e maker, in d e s c r i b i n g it, states that it is not a pressure r e d u c e r or regulator, t h a t the flow of gas t h r o u g h it is not c h a n g e d b y v e r y wide variations of pressure, and that it secures a uniform rate of s u p p l y to the burner, with little or no reduction of pressure. T h e i n v e n t o r of the Boore burner, Mr. Lewis Boore, of Buffalo, N. Y., states that he e n d e a v o r e d to p r o d u c e a reliable and simple a u t o m a t i c g o v e r n o r b u r n e r of low cost, w h i c h w o u l d indicate practically correctly for a v e r y wide r a n g e of pressure, w i t h o u t h a v i n g such an e x t r e m e accur a c y or such close a d j u s t m e n t as to d e s t r o y its utility. W m . S u g g & Co. m a k e t w o kinds of v o l u m e t r i c burners, a steatite float g o v e r n o r and a leather d i a p h r a g m g o v e r n o r burner. Sugg's patent "Alexandra" governor burners combine g r e a t e c o n o m y with efficiency, and p r o d u c e a brilliant, white, silent light. T h e y are fitted with steatite float governor,
416
[J. F. I.,
Gerhard:
and the superior light attained is also a result of adopting double annealed Albatrine globes with wide opening. A n even better flat-flame burner by the s a m e maker is Sugg's patent "Christiania" governor burner, fitted with a specially prepared leather diaphragm governor, with Sugg's patent table top circular slit steatite b u r n e r tip. Sugg's London improved A r g a n d burner always has a governor b u r n e r attached to the fixture. Mr. Wilder calls attention to the fact that his governor burner, to operate well, requires a full street pressure. This rule is applicable to all volumetric burners ; hence, where these are used, a pressure regulator should not be used at the meter. * In order to show, by actual experiments, how nearly uniform the consumption of gas remains with governor burners, I refer the reader again to Mr. Butterworth's able paper on governor burners, wherein is published the following table, showing the gas consumption of a n u m b e r of such burners under varying pressures : TABI,~ V.
Pressure, .
{~
. . . . . . . . .
CU, f l .
Six-foot governor burner, . Six-foot governor burner, . Five-foot governor burner, Five-foot governor burner, Five-foot governor burner, Adjustable burner, ..... Adjustable burner, ..... Adjustable burner, • ....
. . • • •
p e r hr. 6"20
5"95 4"50 4"5o ,4"9o 5"60 4"96 4"95
15 IT cu. f t . cu. fe. cu. . cu. f t . ft. .it. p e r hr. p e r lzr. p e r ~rr• # e r hr. #cu. e r hr. pcu. e r hr.
6'20 6"5 ° 4'50 4"65 4"95 5"50 5"97 4"95
6"35 6"20 4"55 4"55 4"95 5 "40 6"21 4"95
6'30 6"20 4"55 4"65 4'95 5"30 6"19 4"95
6"25 6"05 4"65 4"70 4"9 o 5"O7 6"05 4"95
6 '25 6"15 4"65 4"65 4"9° 4"80 5"89 4"95
6"4C~ 6"05 4"60 4"55 4"90 4"60 569 4"95
T h e last burner in the table showed a perfect uniformity of supply under the wide range of pressures used in the test. Some of these governor burners are adjustable, and if they are required to pass a certain q u a n t i t y of gas per hour, a nice a d j u s t m e n t is necessary, which can only be accomplished if the candle power and quality of gas, its pressure and specific gravity are known. A governor burner adjusted for a gas of certain specific gravity would not remain correct for a gas of different density, or for a n y temperature which would change the density.
June, t894.]
Gas Burners, etc.
4x 7
Both, t h e p r e s s u r e r e g u l a t o r s on t h e m a i n service pipe and the g o v e r n o r burners, accomplish a s a v i n g in gas cons u m p t i o n b y p r e v e n t i n g useless waste, a m o u n t i n g to a r e d u c t i o n of from t w e n t y to forty per cent. in the gas bills. O t h e r incidental a d v a n t a g e s g a i n e d are: a g r e a t improvem e n t in t h e steadiness of a gas flame w i t h o u t r e g a r d to the n u m b e r of b u r n e r s lit or t h e c o n s t a n t l y c h a n g i n g street pressure ; t h e h i s s i n g or r o a r i n g noise, the blowing, and the flickering of lights is p r e v e n t e d ; the illumination b e c o m e s s t r o n g e r ; t h e s m o k i n g of A r g a n d b u r n e r s is p r e v e n t e d , and the air of the room is v i t i a t e d to a m u c h smaller e x t e n t b y the p r o d u c t s of i m p e r f e c t c o m b u s t i o n . With governor burners, however, t h e s e results are a t t a i n e d in a h i g h e r degree than w i t h p r e s s u r e r e g u l a t o r s on the service pipe. T o s u m up, practical considerations m u s t decide w h i c h form of r e g u l a t i o n it is b e s t to adopt. In this connection the following rules are to be r e c o m m e n d e d , viz. : (a) W h e r e the street m a i n s are large and the differences of level insignificant, use either check b u r n e r s or volumetric burners. (b) W h e r e t h e street m a i n s are small, or the p r e s s u r e is low or the h o u s e pipe insufficient, n e i t h e r m e t h o d of regulation should be employed. (c) W h e r e the t o w n is hilly and there are considerable differences of elevation in the districts, a p r e s s u r e r e g u l a t o r will answer, p r o v i d e d the h o u s e pipes are large, the gas keys full bore, and t h e b u i l d i n g only a few stories in height, and not of g r e a t e x t e n t laterally. (d) W h e r e in such districts the b u i l d i n g s are high or v e r y large, a pressure r e g u l a t o r on each floor should be used, t o g e t h e r w i t h r e g u l a t i n g check b u r n e r s at the fixtures, b u t in such cases g o v e r n o r b u r n e r s are a simpler remedy, and are, therefore, to be preferred. I I I . - - G L A S S GLOBES A N D GLOBE H O L D E R S .
Flat-flame b u r n e r s are, as a rule, s u r r o u n d e d with glass globes, and practical experience and o b s e r v a t i o n have e s t a b l i s h e d the fact t h a t if these are u n s u i t a b l y arranged or of i m p r o p e r shape, t h e y c o n s t i t u t e a n o t h e r factor, causVoL. CXXXVII 27
418
Gerhard."
[J.F.L,
in K deficient illumination, i m p e r f e c t combustion, and freq u e n t l y a w a s t e of gas and a c o r r e s p o n d i n g increase in the gas bills. Gas globes are used chiefly to p r o t e c t open flames a g a i n s t d r a u g h t , and t h e r e b y to p r e v g n t the a n n o y i n g u n s t e a d i n e s s and flickering of lights. T h e y are also e m p l o y e d to s h a d e the eyes from the direct glare of t h e light, to diffuse and soften the light, also to add to the good external a p p e a r a n c e of gas fixtures ; and finally, gas globes are, for safety's sake, placed over n a k e d lights to shield the flame from c o m i n g into direct c o n t a c t with i n f l a m m a b l e materials. F r o m all of w h i c h it follows that gas globes are used for u t i l i t y even more than for ornament, hence their design and construction should be b a s e d on sound principles. In order to Obtain g o o d illumination, and to avoid the flickering of gas lights, the air n e c e s s a r y for c o m b u s t i o n should be b r o u g h t to the flame in a slow, u n i f o r m and s t e a d y current. If the air s u p p l y is insufficient a flame is apt to s m o k e and will blacken ceilings and c o n t a m i n a t e t h e air. If the air r u s h e s to the flame in a violent manner, this will d e s t r o y the s t e a d i n e s s of the light, the light will flicker and j u m p , and it has the f u r t h e r d e t r i m e n t a l effect of cooling the flame, and t h e r e b y r e d u c i n g its brilliancy. T h e old style glass g l o b e s were q u i t e defective in shape, form and material. T h e y were m a d e w i t h v e r y narrow top and b o t t o m openings, or if tulip-shaped and w i d e n i n g at the top, the b o t t o m o p e n i n g was e x t r e m e l y narrow, b e i n g often b u t one and one-half or two inches in diameter, and, w h e r e such globes were in use, the ceiling was often the only welli l l u m i n a t e d place. Tile result was that, o w i n g to the smallness of the b o t t o m aperture, the c o n t r a c t e d g l o b e acted like a chimney, c a u s i n g the air c u r r e n t to i m p i n g e upon the flame to such an e x t e n t as to seriously d i s t u r b the flame, and t h e r e b y c a u s i n g s a m e to flicker in a d i s t r e s s i n g manner. A n o t h e r defect of the old style globes is that t h e y form d u s t traps, and t h a t t h e y are readily soiled in lighting. rf, a d d e d to this defect in the globes, the g a s p r e s s u r e at the b u r n e r was excessive, t h e r e s u l t i n g i l l u m i n a t i o n necessarily was v e r y imperfect. To d e t e r m i n e the actual loss of
June. I894.]
Gas Burners, etc.
4I 9
l i g h t due to small o p e n i n g s in globes, Dr. W a l l a c e made a series of experiments, which showed t h e following results : A n a k e d flame was tested a n d f o u n d to g i v e I6"8 candle light. T h e same flame, s u r r o u n d e d w i t h a seven and one-half inch d i a m e t e r clear globe, w i t h two and t h r e e - e i g h t h inch b o t t o m opening, gave I5"4 candle lights, or loss of 8"3 per cent. T h e s a m e flame, s u r r o u n d e d with a seven and one-half inch d i a m e t e r clear globe, w i t h two and one-quarter b o t t o m o p e n i n g gave 15"2 candle light, or loss of 9"5 per cent. T h e same flame, s u r r o u n d e d w i t h a seven and one.half inch d i a m e t e r clear globe, w i t h two inch b o t t o m opening, gave I3"6 candle light, or loss of n i n e t e e n per cent. T h e same flame, s ~ r r o u n d e d w i t h a seven and one.half inch d i a m e t e r clear globe, w i t h one and one-half inch b o t t o m o p e n i n g gave I3" candle light, or loss of t w e n t y - t w o per cent. T h e same flame, s u r r o u n d e d w i t h a seven and one-half inch d i a m e t e r clear globe, w i t h one inch b o t t o m opening, gave I2" candle light, or loss of 28"6 per cent. All glass globes, moreover, absorb a certain a m o u n t of light, and t h e l o s s of l i g h t a n d c o r r e s p o n d i n g waste of gas d u e to this cause increases the more opaque the glass globe is. F a n c y " r u b y " or o t h e r colored, etched or otherwise decorated globes in p a r t i c u l a r o b s t r u c t a large a m o u n t of light, and hence increase gas bills b y the necessity of keepi n g a l a r g e r n u m b e r of l i g h t s b u r n i n g on a chandelier. It is s t a t e d on,good a u t h o r i t y t h a t l i g h t is o b s t r u c t e d as follows: F e r cenl.
By clear glass globes, . . . . . . . . . . . . . . . . . . . IO'I5 By slightly ground globes, . . . . . . . . . . . . . . . . 24 By globes ground all over, . . . . . . . . . . . . . . . . . 25"4o By opal thick glass globes, . . . . . . . . . . . . . . . . . 35'6o By colored or painted globes, . . . . . . . . . . . . . . . . 64 L a s t l y , the globes w i t h n a r r o w b o t t o m and wide top o p e n i n g are objectionable, because i n s t e a d of c a s t i n g l i g h t o u t w a r d and d o w n w a r d by reflection, t h e y throw the greatest a m o u n t of l i g h t up to the ceiling, where it is not wanted. I t m a t t e r s little how a t t r a c t i v e in shape and artistic in o u t l i n e such old style globes are; as long as t h e y tend to d i s t u r b the flame t h e y are clearly objectionable. These d e f e c t s h a v e been g r a d u a l l y recognized, and such globes
420
Gerhard.
[ J. F. I.,
with contracted openings happily are now being discarded. The new form of globes has wide bottom openings, which admit the air without causing a draft; the shape of the globe is designed more with a due regard to its proper functions than solely from a decorative point of view. Such globes induce a straight, upward, gentle current of air, and the flame remains steady and bright. All globes of modern construction have bottom openings four and five inches in diameter, and have the incidental advantage that a portion of the light falls directly downward without being obstructed. The Sugg "Alez~andra" and " C h r i s t i a n i a " burners are surrounded with globes of most desirable shape and material; the Broenner burners have similarly shaped " Cornelian" globes; and Wilder, in the description of his volumetric burner, recommends globes four and one-half inches in diameter at the bottom and five and one-half inches at the top. R e g a r d i n g the material for globes, clear crystal glass is the best, because it absorbs the least light. Still, it oftentimes becomes desirable to render the light of a gas flame soft and mellow, and f ~ r such cases thin milk-white opal globes are best and quit~ effective. Sugg uses with h i s b e s t fiat flame governor burners double annealed large size globes, with wide bottom opening, which he calls " Albatrine " globes, and which give a particular softness to the light. The cheaper kind of thick opaque white glass globes should be avoided, as they intercept as much as seventy to eighty per cent. of light. In connection with globes, it is noteworthy that somewhat increased illumination is obtained by using globe holders which are as little light obstructing as possible, i.e., very thin sheet brass or brass wire globe holders. T h e old style fixtures had h e a v y and cumbrous cast brass holders, or heavy discs, triangles or rings, all of which are objectionable, because they intercept a portion of the light, and cast a shadow downward and thereby cause a loss of light. T h e new shadowless globe holders, made of three simple prongs of brass wire, not more than one-eighth of an inch thick, and
June, I894..]
Emery and other Abrasives.
42!
without any rims whatever, are r e c o m m e n d e d by all dealers in advanced gas light fixtures. Lastly, the position of the glass globe in reference to the gas flame is of a good deal of importance where it is desired t o secure a steady, bright light. It has been found long ago, by experiment, that by arranging a shadowless globe holder on the burner in such a m a n n e r as to place the level of the bottom of the flame in line with the bottom edge of the globe, the flame will burn very quietly and steadily, and will not be affected much, if any, by the ascending air current, whereas if the flame is set higher it is apt to flicker. This correct position and shape of a glass globe has been pointed out repeatedly by such gas engineers as Wilder, Peebles, Sugg, Broenner, Silber and others, in connection with their gas burning appliances; but on the whole, in practice, little attention has been paid to this simple yet efficient rule. [ To be concluded.]
E M E R Y AND O T H E R A B R A S I V E S . ~ BY T. DUNKIN PARET, President of t h e Tanite Company.
[ Concluded from p. 372.]
While small specimens of corundum, in the form of imperfect sapphires, have come from Montana, where the existence of this mineral has long been known, no other locality has yielded corundum except that well-known belt which reaches from Massachusetts to Georgia, and which seems to have its center in the corner where North and South Carolina, Georgia and Tennessee come together. In this belt the localities where corundum occurs are innumerable, but the prevalence of the mineral is a poor indication of its quantity. Corundum occurs in pockets, seams, sand veins, narrow streaks and detached crystals, seldom in large mass. Chester County, Pa., is, apparently, the only locality where large solid masses have been found. The