400 
The Philippine Journal of Science 
1920 
There are still factories that do not feel justified in making this 
product, due to the cost of manufacture and the care that must be 
exercised; also because the possibility exists that the product may be 
refused, or that it may have to be sold for as much as 20 centavos a 
picul less than the price agreed upon. Even at the reduced price the 
factories are usually glad to get rid of the sticky stuff. 
At the same time, no by-product of the sugar factory has been so 
neglected, while as a matter of fact no other product is so easily man- 
ufactured, and even so low a market value as 48 to 52 centavos per 
picul would warrant its manufacture. However, the manufacturer who 
contemplates starting in this business must first abandon the idea that 
his old pans, etc., which are no longer fit for the manufacture of sugar 
proper, constitute all the equipment he will require in the new enterprise. 
To begin with, he will need a first-class vacuum pump, one that will 
give a vacuum of at least 69 centimeters. If there is no such pump 
on the grounds, or should its purchase be considered unnecessary, troubles 
are bound to result and disappointment is sure. It is better to sell the 
molasses in liquid form than to try to solidify it without a good pump. 
Preferably a separate pump should be used for the molasses pan, for the 
following reasons: 
(1) To obtain a constant vacuum not influenced by the opening or 
shutting of the valves on the other pans. 
(2) Because the vapors attack the walls of the juice catchers and 
pipe lines to such an extent that cases have occurred in which after two 
seasons these had to be replaced. If this happens when a separate pump 
is used — and it is less likely to occur when a high vacuum is maintained — 
it will be necessary to repair only the line for the molasses pan; while, 
otherwise, perhaps the whole piping system for the central condensation 
would have to be repaired or even renewed. 
The best way is to insure a connection between the vacuum line for 
the molasses station and the other pans, but separated by a tight-shutting 
valve or a blind flange. This plan offers the advantage that, if the 
central pump breaks down, the material can be worked off in the pans 
with the other vacuum pump, though obviously that process is bound 
to be slow. 
The pan itself must be a coil pan, in which the coils are neither too 
close together nor too close to the wall of the pan. This will facilitate 
discharge and will give better circulation. 
If both pump and pan conform to these specifications, one can be sure 
of a good product, and the total time of boiling should not exceed between 
six and seven hours for a strike of 135 hectoliters, inclusive of cooling. 
Water circulation in separate iron coils is then unnecessary, and even 
undesirable, since the iron coils harm the circulation between the steam 
coils. 
Boiling can be finished in five hours, if necessary, with live steam, and 
it is recommended that the finished molasses be allowed to cool for from 
one to two hours under vacuum. A pan with a capacity of 135 hecto- 
liters is sufficient for a grinding capacity of 14,000 piculs 4 of cane, and 
will handle all the molasses, taking into account the time required for 
4 The Javanese picul is about 1 pound less than the common Philippine 
picul. — H. J. C. 
