Pittsburg dispatch. [volume] (Pittsburg [Pa.]) 1880-1923, 1892-11-16

the oil is vapoIiZed, or in technical Ian
guage, suffers destructive distiliation. All
| the elements OF the oil are still present and
| if lighted match is applied to the column
OF smoke it will ignite and burn with
bright flame. Similarly, when bituminous
| coal is charged on the top of fire it cannot
| all be heal ed instantaneously, but portions
OF it will suffer destructive distillation as it
| gradually approaches dead heat, and a
| all parts OF the freshly added fuel where the
temperature is not high enough to ignite 1t.
This, yellow smoke consists mainly OF
which give to coal smoke its adhesive and
| greasy character.
II we could always have a flame playing
| over all portions of the JoD OF lire, and at
the same time an ample supply of hot air
thoroughly mixed with the Iuel gases, there
woulu never be any notable quantity OF
either yellow or black smoke passing up the
chimney. Theoretically the complete u boli-
tion OF smoke can be secured by having a
top flame and top supply OF hot air, but
just here is where the practical difficulties
begin, Tor however ample may be the admis-
sion of air to the ashpit, and however well
cleared may be the suriace OF the CRATE bars,
the passage OF air through four or five
inches of IncanGescent fuel completely de-
prives it of free oxygen, so there is none
available to ignite the freshly charged coal.
Mixing the Air With the Gases.
But air admitted simply through slits in
the fire door. while helping to keep up a top
flame, yet being cold and imperfectly dis
q, Will chill some pOrtlOnS Oh the 1uel
gases below the igniting point, and conse-
QuentIy imperfect combustion, with the pro-
duction of black smoke, will result. Hence,
al essential requirement. OF devices for
smoke-prevention is: an ample, timely and
thorough mixture of air with the combust-
ible gases distilling from the fuel
The style of iur mace known as the "regen-
erative" is the best known plan for pre-
heating the air which is to be supplied to the
fuel through the air door. 1t, however, is
not suited for boilers and for many other
applications of fuel. The former are prob
ABLY the greatest smoke producers in Pitts
burg and Aleg heny and are daily becoming
more numerous, owing to the increasing use
power in buildings throughout these cities
Much of their smoke is due TO badly con-
structed furnaces and to the fact that the
boiler CAPACITY is insufficient to properly
fulfiIltne duty required or them.
In order to preheat the top air before it
reaches the fuel gases ft is sometimes ad-
mitted through openings in the brfckwork
fire bridge. This is a partial remedy only,
because the air is rarely sufficiently heated
or mixed thoroughly enough with the dis
tilling products of the coal.
Boilers Must Not Be Crowded
These are mechanical arrangements more |
or less complicated and costly, designed to |
supply the fuel not inter Imittently but con. |
stantly and to spread it in thin layers over |
the fire. There are several very good |
stokers now on the market which accom-. |
plisn the desired result with greater or less |
success according as they are permitted to
feed the coal slowly or rapidly. II the iced. |
ing 10 made slow enough the suppression Of |