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Fuel and its use
156
Fuel and its Use.
of the usual size of about 1~ inches diameter. It is scarcely necessary to call attention to the economy of original construction and finish, of this plan for balanced valves, and the facility of access if repair should ever be required ; but these are obviously not the least of its merits.
FUEL AND IT8 U8E. By PROF. H. FRITZ, Zurich. [From
the Journal of Applied Science, A u g u s t 1, 1876.]
Although frequent attempts have been made to render the use of fuel as advantageous as possible, the results are far from satisfactory, as only part of the heating power is utilized. The difference between theoretical and effective heating power for various sorts of fuel may be seen by the following table, which gives the number of pounds of water evaporated by one pound of fuel H e a t i n g Power. Fuel. Theoretical.
])et ro]eul'Ii.., ..........................
Anthracite ........................... Coal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Charcoal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coke . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B r o w n coal . . . . . . . . . . . . . . . . . . . . . . . . . . . Peat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Wood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Straw ..................................
16'30 12.4~i 11-51 10"77 9--10"8 7'7 5 5--7'4 4'3--5'6 8.0
I n S t e a m Boilers. In Open Boilers3 10--14 5"2--8 6--6.75 5--8 2.2--5.5 2.5--5 2.5--3-75
5-2 3.7 1 '5--2.3 1-7--2.8 1-85--2.1
1 '86--1-92
As regards the heating of steam boilers, Mr. Thompson found, by a series of experiments, that, on an average, only forty-seven per cent. of the theoretical heating power of the fuel is utilized, the remainder being lost through imperfect combustion, radiation, and other causes. Since portable engines have been arranged for straw burning, this fuel has become of great importance for agricultural purposes. Trials at the Vienna Exhibition proved that one pound of strawis capable of evaporating from 181 lb. to 1"97 lb. of water into steam of seventy pounds pressure aM 805°6 Fahr. Compared with Thompson's figures for other fuels, straw would seem to give more
Fuel and its Use.
157
work than even coal ; but the trials in Vienna were made with Exhibition engines, and under the most favorable circumstances. Amongst the other caloric engines tried up to the present time, only those working with h o t air, exploding gas, and exploding vapor of petroleum have proved of practical use. The following table shows the comparative merits of different systems : - -
Air Engines.
Belou . . . . . . . . . . . . . . . . . . . . . . . . . Leawitt ....................... Lel~mann . . . . . . . . . . . . . . . . . . . . Leauberau ................... Ericsson ......................
Oas Engines.
Otto a n d L a n g e n . . . . . . . . . . . Hugon ........................ Lenoir ........................
Petroleum Engine. Itock .........................
P o u n d s of F u e l p e r Hour, and H. P.
Relation between Effective and Theoretical Work of Fuel.
3.8--4.84 6 10.12 9.9--13"15 11--16-5
6'0--4"1 3.5 1-9 2.0--1.4 1.8--1.2
Quantity of Gas reduced to O o a l in lbs.
3-96--6 9"9 9'9--12
5.0--3.5 2.0 2.0--1.8
P e t r o l e u m in lbs.
1.65--2.86
8"4--i.6
Comparing the different steam engines with these motors, i t is found that as regards work they are nearly equal, or rather, the duty varies for steam engines and other caloric motors almost between the same limits. To show this, the following table is arranged according to the work of the different motors : - P e r cent.
Small high-pressure engine without expansion . Air engine, Ericsson . " Leaubereau " Lehmann . Gas engine, Lenoir . " Hugon . Portable steam engine . . . . High-pressure steam engine with expansion . Air engine, Leawilt. " Belou
.
!'8 1"8 1'8 1"9 2 0 2"0 28 3"0 3'5 4"1
158
.Book Notice.
Condensing engine with expansion 4"5 Gas engine, Otto and Langen 5"0* Petroleum engine, ttoek . . 8"4 Large steam engine, best make . 9"0 Although, according to this table, the work of high pressure steam engines is less than that of gas or air engines, the cost of fuel for the latter still exceeds that for steam engines from 2"5 to 5 times, a circumstance which explains the fact that, notwithstanding the many advantages of air or gas engines, they are not able to replace the ordinary liigh pressure steam engine.
Book
hTotice.
HEAT.--R. S. MeCulloch, C.E., Professor of Mechanics, Washington and Lee University, Va. 12mo, ')88 pp. D. Van Nostrand, New York, 1876. It would be difficult to find a parallel example of so excellent, thorough, and exact a text book, as completely wanting in inductive arrangement; while at the samc time it is not known where to look for any corresponding prescntadon of the dynamics of heat of equal clearness or accuracy. If, however, it is assumed that the book is a r(!.-umg of lessons--that it has followed, and accompanied courses of physics and practical mechanics, in which the several propositions have originated, then the mathematical demonstrations in some order of sequence, will have become invaluable aids to the learner, and this recapitulation in the groups chosen, will be highly advantageous. In the preface of the work the author speaks of the retrogression " o f scientific, as well as classical, education in this country, and superficially is the fashion of the day," by way of apology for the use of the concise language of modern mathematics. Without denying the decline of Greek scholarship--Is not the publication of this work in this country at all an indication of progress ? The first page of notation, which is not that of the " fluxional calculus," is evidence of the growth of English m:lthematical science during the past fifty years. T R E A T I S E ON TIIE MECIIANICAL TIIEORY OF
* This rate of actual economic effect for the Otto and Langen engine is delusive in some regards. First, there are obvious limits of size for the Otto and Langen principle of action when reduced to working practice, so that the relative economy would be affected (impaired) materially when an engine develops any large quantity of power, s a y above 8 to 10 horse power, and second, the Otto and Langen engine is especially economical in the performance of irregular labor, in which regard it appears to p r e s e n t striking advantages over any other engine known. The English reports of this engine also place it higher in the scale than is shown on this t a b l e - - S e e JOURNAL OF THE FRANKLIN INSTITUTE, vol. Cp p. 262. (Note
by E~,.F. I. J.)
Fuel and its Use.
of the usual size of about 1~ inches diameter. It is scarcely necessary to call attention to the economy of original construction and finish, of this plan for balanced valves, and the facility of access if repair should ever be required ; but these are obviously not the least of its merits.
FUEL AND IT8 U8E. By PROF. H. FRITZ, Zurich. [From
the Journal of Applied Science, A u g u s t 1, 1876.]
Although frequent attempts have been made to render the use of fuel as advantageous as possible, the results are far from satisfactory, as only part of the heating power is utilized. The difference between theoretical and effective heating power for various sorts of fuel may be seen by the following table, which gives the number of pounds of water evaporated by one pound of fuel H e a t i n g Power. Fuel. Theoretical.
])et ro]eul'Ii.., ..........................
Anthracite ........................... Coal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Charcoal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coke . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B r o w n coal . . . . . . . . . . . . . . . . . . . . . . . . . . . Peat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Wood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Straw ..................................
16'30 12.4~i 11-51 10"77 9--10"8 7'7 5 5--7'4 4'3--5'6 8.0
I n S t e a m Boilers. In Open Boilers3 10--14 5"2--8 6--6.75 5--8 2.2--5.5 2.5--5 2.5--3-75
5-2 3.7 1 '5--2.3 1-7--2.8 1-85--2.1
1 '86--1-92
As regards the heating of steam boilers, Mr. Thompson found, by a series of experiments, that, on an average, only forty-seven per cent. of the theoretical heating power of the fuel is utilized, the remainder being lost through imperfect combustion, radiation, and other causes. Since portable engines have been arranged for straw burning, this fuel has become of great importance for agricultural purposes. Trials at the Vienna Exhibition proved that one pound of strawis capable of evaporating from 181 lb. to 1"97 lb. of water into steam of seventy pounds pressure aM 805°6 Fahr. Compared with Thompson's figures for other fuels, straw would seem to give more
Fuel and its Use.
157
work than even coal ; but the trials in Vienna were made with Exhibition engines, and under the most favorable circumstances. Amongst the other caloric engines tried up to the present time, only those working with h o t air, exploding gas, and exploding vapor of petroleum have proved of practical use. The following table shows the comparative merits of different systems : - -
Air Engines.
Belou . . . . . . . . . . . . . . . . . . . . . . . . . Leawitt ....................... Lel~mann . . . . . . . . . . . . . . . . . . . . Leauberau ................... Ericsson ......................
Oas Engines.
Otto a n d L a n g e n . . . . . . . . . . . Hugon ........................ Lenoir ........................
Petroleum Engine. Itock .........................
P o u n d s of F u e l p e r Hour, and H. P.
Relation between Effective and Theoretical Work of Fuel.
3.8--4.84 6 10.12 9.9--13"15 11--16-5
6'0--4"1 3.5 1-9 2.0--1.4 1.8--1.2
Quantity of Gas reduced to O o a l in lbs.
3-96--6 9"9 9'9--12
5.0--3.5 2.0 2.0--1.8
P e t r o l e u m in lbs.
1.65--2.86
8"4--i.6
Comparing the different steam engines with these motors, i t is found that as regards work they are nearly equal, or rather, the duty varies for steam engines and other caloric motors almost between the same limits. To show this, the following table is arranged according to the work of the different motors : - P e r cent.
Small high-pressure engine without expansion . Air engine, Ericsson . " Leaubereau " Lehmann . Gas engine, Lenoir . " Hugon . Portable steam engine . . . . High-pressure steam engine with expansion . Air engine, Leawilt. " Belou
.
!'8 1"8 1'8 1"9 2 0 2"0 28 3"0 3'5 4"1
158
.Book Notice.
Condensing engine with expansion 4"5 Gas engine, Otto and Langen 5"0* Petroleum engine, ttoek . . 8"4 Large steam engine, best make . 9"0 Although, according to this table, the work of high pressure steam engines is less than that of gas or air engines, the cost of fuel for the latter still exceeds that for steam engines from 2"5 to 5 times, a circumstance which explains the fact that, notwithstanding the many advantages of air or gas engines, they are not able to replace the ordinary liigh pressure steam engine.
Book
hTotice.
HEAT.--R. S. MeCulloch, C.E., Professor of Mechanics, Washington and Lee University, Va. 12mo, ')88 pp. D. Van Nostrand, New York, 1876. It would be difficult to find a parallel example of so excellent, thorough, and exact a text book, as completely wanting in inductive arrangement; while at the samc time it is not known where to look for any corresponding prescntadon of the dynamics of heat of equal clearness or accuracy. If, however, it is assumed that the book is a r(!.-umg of lessons--that it has followed, and accompanied courses of physics and practical mechanics, in which the several propositions have originated, then the mathematical demonstrations in some order of sequence, will have become invaluable aids to the learner, and this recapitulation in the groups chosen, will be highly advantageous. In the preface of the work the author speaks of the retrogression " o f scientific, as well as classical, education in this country, and superficially is the fashion of the day," by way of apology for the use of the concise language of modern mathematics. Without denying the decline of Greek scholarship--Is not the publication of this work in this country at all an indication of progress ? The first page of notation, which is not that of the " fluxional calculus," is evidence of the growth of English m:lthematical science during the past fifty years. T R E A T I S E ON TIIE MECIIANICAL TIIEORY OF
* This rate of actual economic effect for the Otto and Langen engine is delusive in some regards. First, there are obvious limits of size for the Otto and Langen principle of action when reduced to working practice, so that the relative economy would be affected (impaired) materially when an engine develops any large quantity of power, s a y above 8 to 10 horse power, and second, the Otto and Langen engine is especially economical in the performance of irregular labor, in which regard it appears to p r e s e n t striking advantages over any other engine known. The English reports of this engine also place it higher in the scale than is shown on this t a b l e - - S e e JOURNAL OF THE FRANKLIN INSTITUTE, vol. Cp p. 262. (Note
by E~,.F. I. J.)