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sai SUGAR-CANE SIRUP MANUFACTURE 49 
All pipe lines, especially in factories using the sulphur-lime 
process, are best made of copper. As copper is expensive, placing 
the apparatus as close together as is convenient effects an economy. 
The zine surface of galvanized-iron piping gradually dissolves, ex- 
posing the juice and sirup to iron surfaces. If copper is considered 
too expensive, plain iron pipe may be coated on the inside with a 
heat and acid resistant paint by closing one end, filling the pipe with 
paint, pouring it out, and allowing the pipe to dry. Two coats of 
paint are usually sufficient. 
The plans listed in Table 11 were selected after a careful con- 
sideration of all governing factors. It is more economical and con- 
venient to drive the mills in the smaller plants by belts; in the larger 
mills direct gearing to the engine is almost always used. An ordinary 
slide-valve engine is sufficient for the smail plants. Corliss engines 
are used extensively for driving the larger units. The sizes of engines 
required for plants of varying size are shown in Table 11. 
RAW-JUICE TANK 
A small, plain, galvanized-iron, painted sheet-iron, or copper tank . 
of rectangular cross section (the raw-juice tank) is placed near the 
mill to receive the juice from the juice strainer. The sizes required 
are shown in Table 11. The juice is generally carried to this tank 
through a canal by gravity. 
RAW-JUICE PUMP 
The pump used to pump the juice from the raw-juice tank to the 
sulphur tower may be of the centrifugal, direct-acting, or power 
type. The centrifugal type is less expensive and lends itself to an 
easy method for driving. The direct-acting type is often more 
convenient in larger plants. | 
SULPHUR TOWER 
Among the methods of sulphuring juice are the following: (1) 
Blowing sulphur dioxide directly into the juice through perforated 
pipes placed near the bottom of a suitable tank; (2) conducting the 
raw juice into a sulphur box, from which it is pumped to the defecators 
or heaters, the pump being allowed at the same time to draw in 
sulphur dioxide through the sulphur box; (8) using a sulphur tower 
(fig. 16). The principal objection to the first method is that the 
perforated coils scon become stopped up with sulphur and the 
sulphur dioxide has a detrimental action on the blower. The second 
method gives better results than the first, but practically all of the 
mixing of the sulphur dioxide with the juice takes place in the pump, 
soon destroying the linings, valves, etc. Moreover, this method is 
unsatisfactory for controlling the degree of sulphuring. The third 
method, generally considered the best, provides a means for con- 
trolling the degree of sulphuring and conducts the objectionable 
excess fumes to the outside of the building. 
The sulphur tower, used when the sulphur-lime method of clarifica- 
tion is employed, is made as follows: 2 by 12 inch planks of good 
lumber, preferably cypress, placed as shown in Figure 16, are screwed 
or nailed to 3 by 4 inch crosspieces, to form the sides, and bolted 
together with long bolts. The top is made of 2 by 12 mech lumber, 
56750°—25 | ——4 
