EXTRACTION TEST OF A MODERN SUGAR CENTRAL. 
By L. W. THURLOW and D. S. PRATT. 
(From the Laboratory of Organic Chemistry, Bureau of Science, 
Manila, P. I.) 
INTRODUCTION. 
_ The primary object of this paper is to place before the sugar 
manufacturers in the Philippine Islands some reliable data on 
the operation and efficiency of a modern central of the smaller 
type working under conditions such as are met with in pioneer 
work where exact control is hindered through lack of laboratory 
facilities, skilled workmen, weighing facilities, ete. At present 
these conditions are more or less inevitable. For this reason 
we report results which were obtained when average, rather 
than exceptionally good, conditions of manufacture prevailed. 
By doing this we believe that our conclusions concerning the 
advantage of refining sugar by small centrals over the older and 
commoner methods now in vogue will be much more reliable 
and convincing than a similar but more spectacular treatise 
based upon theoretical or ideal conditions. The results included 
in this report were obtained under very disadvantageous cir- 
cumstances, but they are considered accurate enough for the 
purpose involved and of value to sugar producers of whom the 
majority in the Islands at this time are not acquainted with 
central factory methods. 
DESCRIPTION OF THE PLANT. 
Our tests were made during a four-day run of a small modern 
central located at Muntinlupa, Rizal Province. It is a small 
mill with a capacity of about 100 tons of cane per day of twenty- 
four hours, and was designed by the Harvey Engineering Com- 
pany of Glasgow. 
The crushing portion consists of a 3-roller mill and crusher, 
the latter being of the conical groove type. It is fitted with a 
cane carrier and bagasse feeder which are operated by 2 hori- 
zontal, return tube boilers, arranged with step-grates for burning 
green bagasse. A reciprocating, slide valve engine is used to 
drive the mill and carriers. A plunger pump is attached to the 
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