18 
BULLETIN 1158, U. S. DEPARTMENT OF AGRICULTURE 
Sw££T 
PnrATors 
WaxchousA Ckatc'C- 
**Trifii^?r„ 1 
Stock Feed 
Fig. 11. — Flow diagram for swee 
of the crude sirup was then added and thoroughly mixed, and this 
mixture was pumped into the cooling tank in which the crude sirup 
was stored. The sirup was then pumped into the filter press. The 
filtrate was usually clear from the start. A small belt-driven pump 
was attached to the delivery tank, with valves so arranged that the 
filtrate could be sent either to the cooling tank or to the evaporator, 
as desired. The pressure used in filtering was allowed to build up 
gradually during the filtration to about 25 pounds. 
Fifty pounds of kieselguhr proved to be nearly enough to fill the 
18 frames of the filter press. The filter cake was washed by pumping 
cold water in through the feed ports. Laboratory experiments, using 
a small filter press of the same type, showed that it was practicable to 
reignite and reuse the kieselguhr. This, however, was not done in the 
field trials at Fitzgerald. 
EVAPORATION OF FILTERED SIRUP. 
After being filtered, the sirup was evaporated to the desired 
density, using the evaporator employed for crude sirup, thoroughly 
cleaned, of course. As the dilute filtered sirup in boiling foamed 
more than the crude wort, a special procedure was evolved to over- 
come this difficulty. Unless the level of the sirup was kept rather 
low in the evaporator, it had a tendency to foam over every time 
the freshly filtered sirup was added. When a low sirup level was 
maintained, however, the steam gauge at the head of the evaporator 
coils became a convenient guide in indicating when to add a por- 
tion of the freshlv filtered sirup. As the contents of the evaporator 
approached the densitv of the finished sirup, the steam pressure in 
the coils gradually increased to 40 or 45 pounds. As the stream 
of filtered sirup was slowlv added by means of the pump, this pres- 
