The Pacific commercial advertiser. [volume] (Honolulu, Hawaiian Islands) 1856-1888, 1882-03-25
Committee on NI~achIncry Report.

Committed ON NTachIncry Report
In the limited time at its disposal, the com
mlttee has not been able to collect the facts and
figures it would be desirable 10 place before the
mil owners and managers, but viii present a few
items IN regard to improvements in machinery,
which have come under the observation of its
members, which possibly may be worthy of
discussion and investigation on the part of the
Association. y number of the most notable de-
p~artures from the STYLES of machinery, and boil
ing house apparatus usually adopted at the mills
on these Islands are to be found at the mills of
the Hawaiian Commercial Company on Maui.
and the results of some of these improvements
will be found interesting. We will present items
in regard to several departments.
CRUSHING MACHINERY.
The first mill erected by the H. c. c.. was of
the kind known as the Five Roller Mill, the first
of its kind erected on these Islands, though by
no means unknown in Cuba and other sugar pro-
ducing countries, and the results obtained were
such that the three mills planned subsequently
were made of the same kind. The Hydraulic
Attachment, - however on these mills we believe
was applied here first. BY means of it the up
per rolls are forced down by hydraulic pressure,
so that the same crushing force is exerted on a
small quantity of cane as on Il large mass, and
.irregularity of feeding does not result in imper-
feet grinding. The five rollers are arranged in
two sets. \ set of three, and n set of two. The
set of three is similar to any three roll mill in
the set of two, one roll is directly over the other.
the trash from the three rolls is carried by an
apron to the pair, and leaves them dry enough
to be taken directly to the furnaces. The amount
of juice extracted from the trash by the second
set of rollers is 16 per cent. of that obtained by
the first set. All of the cane of the whole crop,
yielding over l 700 tons of sugar, was weighed as
1t was brought III on the cars, and the juice OBJ
tanned was Il per cent. of the cane. tits believ-
ed that there are not many mills, that can show
an efficiency IN crushing power equal to that. 1t
Is unfortunate that no other mills have facilities
for weighing cane, so that exact results can be
compared. \ very good test of the efficiency of
any mill can be made however by ascertaining
the amount of moisture remaining in the trash
after crushing, weighing u quantity of trash Just
from the rolls, drying 1T thoroughly, and weigh
ing again. The loss III weight will be the amount
of moisture to be ascertained. Tested in this
way, the trash from the II. c. Co.'S Mill was
found to contain So per cent. of moisture, or in
other words. from 100 lbs of cane, II lbs of juice
were obtained, and of the residue IL lbs were
moisture, and IS lbs dry trash. Although the
largest mills crush nearly if not quite as efficient
ly as this, it seems that with the five roller ar
rangement, a much larger amount of cane can be
put through in a given time than with the triple
rolls OF the same size.
CANE ENGINE.
The use of the compound engine, for driving
a mill, has not been known anywhere on the Is
lands, except at the H. G.. Co.'S Works. Those
who understand the principles of the compound
engine Will perceive that one result would be, a
very small proportion of exhaust steam to use
afterwards in cleaning or evaporating. There is
probably greater economy of steam in using it
so as to get as much work as possible out of it
at once than to depend on utilizing a large amount
of exhaust, although it would take careful exper-
iment and more or less intricate calculations, to
establish the fact. There is no more exhaust es-
Gaping from these engines than barely sufficient
to heat the juice before it passes into the clean
ing pan.
CLEANING PANS.
A great variety of cleaning pans are use on
these Islands. The latest style of those made by
the Honolulu Iron Works, do excellent work.
The pans are about II feet long, 6 feet wide and
2 feet deep, with Il copper coil in the bottom, and
Il scum box at the end. 1t is generally admitted
that shallow pans do better work than deep
ones, both III respect to time and economy of
steam. Some advantages are claimed for con-
tiuuous cleaning in long, shallow pans, where
the juice runs in constantly at one end and out
at the other. Very economical work in pans of
this kind is seen at the mill of Alexander & Bald
win, on Maui excellent results are also obtained
at the II. c. Co : mills where the juice is run
directly into the continuous working pans, in
stead of being heated and skinned first in
the ordinary CHARTERS. The difficulty of Inning
the Juice uniformly will, no doubt, suggest itself
in this connection, and we would call attention
to the apparatus by which this is accomplished.
The lime is slaked and mixed with water in a
small iron tank, in which revolving arms keeps
the milk of the lime agitated. A simple device
prevents the the sediment and unslaked Jumps
from being drawn off, and the milk of the lime
is forced into the juice by a small piston con-
nected Will the juice pump. The stroke of the
small piston is variable at will, so that the
amount of lime-watcr mixed with the juice at
each stroke of the pump can be accurately regu-
lated, and by this means a very thorough mixture
of the lime with the juice is accomplished.
JUICE sTRAINER.
1t has been noted in the experience of two mem
bers OF your committee that the amount of scum
collecting in the CHARTERS, is materially reduced
by the use of very fine juice strainer5. In one
instance a change was made from a strainer of
sheet copper, with holes one-eighth of an inch
in diameter, to n strainer of copper wire cloth,
30 mesh per inch. At the II. c. Co.'s works, it
was found at the first mill that the amount of
skimmings when a moderately fine sieve was
used, was SIX times the amount obtained in the
new mill, with a strainer of centrifugal lining.
Upon noting this fact, the strainer of the old mill
was changed, and the same results were obtained,
rs III the new mill.
EvAPoRATING APPARATUs.
Although the double and triple effect evapora-
ting pans have come into use on these Islands
only within the last two years, no doubt every
one understands the great economy of steam IN
their use. The advantage of this apparatus over
the open evaporators, may be briefly stated thus:
First. The juice is evaporated with from IA
to 16 the amount Of steam required IN an open
evaporatur.
Second. The evaporation being done at
low temperature, the juice is not discolored, as
it is to a certain degree in an open eyaporator.
The first cost of a triple effect apparatus looks
large, but any mill owner who has fuel bills to
pay, can very soon calculate how much he will
gain by saving from 81 to So of the fuel requir-
ed to make steam to concentrate his juice.
There is some choice between the different
STYLES of the double and triple effect pans. OF
those III use in Hawaiian mills, the American
made pans, have some points of advantage over
those Of English make. In the pans of the Eng
lish apparatus the space above the drum is not
large enough, so that the juice will frequently
boil over ii not very carefully watched. In the
American apparatus made by Deeley Il Co., the
space above the steam drum is very high, and be-
sides that the vapor is taken off from the highest
point, and with the patent arrangement in the
top, for catching and returning any overflow, the
liability of loss from boiling over Is reduced to a