The Pacific commercial advertiser. [volume] (Honolulu, Hawaiian Islands) 1856-1888, 1883-02-03
ECONOMY OF FUEL.

The question Of how best TO economic
fuel" says the Canadian Manufacturer, -
as every year becoming of greater import
ance to our manufacturers. Those who use
steam engines for their motive power cannot
afford to keep the old style of fire eaters,
nor yet TO continue using a good engine that
Is out of order. Many of those who use
steam engines do not know that great diff
t%erences exist between differeet engines as
to amount OF steam required to keep them
going. Two engines recently tested, run
ming In factories in this country, show the
following results, obtained from a study OF
the indicator diagrams:
t both factories about seventy pounds
OF steam pressure was carried into the boil
ers, and both engines were supposed TO be
using steam 'expansively.' We say were
supposed to be, advisedly; because in the
one case the indicator showed that it was
mere supposition, and that steam entered
the cylinder at beginning of stroke, about
twenty-five pounds below the boiler pressure.
almost to the end of the stroke. The effect
of this was found to be that about sixty
pounds weight of steam passed through the
cylinder for each horse power every hour
The amount of coal consumed was in keep
AHSt "hp VS. certainly uOt IrSS tldu tcu
pounds per horse power per hour. The in
dicator diagrams revealed the cause of the
trouble. and clearly proved the great ex-
travag,nce of the engine. witch had before
been only partly suspected the large
amount of coal used having been accounted
for by assuming that the boilers were bad
steam makers and so on.
1.-The other engine referred to was found
to admit the steam about ten pounds below
boiler pressure, to carry that pressure for
about one-third of the stroke, and then
sharply 'cut off, expanding the ste I'M dur
ing the remainder of the stroke. The CON
sumption of steam as shown by the indie tor
Was about sixteen pounds per horse power
per hour, or only slightly more than one,
fourth that OF the first mention egine.
"Ihe difference between the economy of
these two engines can be easily accounted
Tor when the diagrams are carefully studied.
The one really worked expansively; the
other, while fitted with expansion valve,
etc., was only n sham, so far as an expansion
was concerned. The first exhausted into the
air, while the other was fitted with an air
pump and condenser. Another source of loss
was occasioned by the large cylinder caps
city for the amount of power obtained. This
led to a diminished pressure. and greater
condensation of steam in the cylinder. The
effect was that at the one factory as much
work was done for six tons of coal as at the
other, which required the consumption of
twenty-four tons. Or, taking coal at So per
ton, $50 did as much at the one as $l20 at
the other. But this does not represent all the
loss, because, in order to supply the large
quantity of steam used or rather wasted, an
increased amount of boiler capacity was
necessary, and three boilers were required
where with a better engine only one would
have been needed. The interest on the first
cost, the ear and tear, and ma intenance of
the two extra boilers, as we'll as the increased
cost of labor in firing t%wenty-four tons, in
stead Of six, should be added to the bare cost
of the fuel in order DO arriva at a fair COZ
psrieo"
"Our manufacturers ought to study ii
fuel question for themselves. They will fin
many points of great interest involved in
and very much that will pay them to app
u to their own business"