THE EXTRACTION OF THE JUICE BY MILLS 



189 



The results may be interpreted as favouring a high speed and a thin 

 blanket of material. 



4. Under pressures up to 60 Ibs. per sq. in. it was found that the volume 

 occupied by bagasse varied inversely as the 2 5th root of the pressure, 

 or symbolically V P' 4 = constant, where V is the volume of the bagasse 

 and P is the pressure. If the bagasse be pressed in a cylinder, H, the height 

 of the column of bagasse under pressure may be substituted for V. Data 

 of an experiment are given below, the results being also expressed as a 

 curve in Fig. 77. 



HEIGHT OF 0-221 LB. BAGASSE, CONTAINING 32-6 PER CENT. FIBRE, ON A SURFACE 



OF 8-43 SQ. INS., CORRESPONDING TO IOO.OOO LBS. CANE . CONTAINING 12 PER CENT. 



FIBRE PER HOUR, AT A SURFACE SPEED IN ROLLERS OF 25 FT. PER MINUTE IN A 78-iN. 

 MILL. UP TO PRESSURES OF 60 LBS. PER SQ. IN. 



Pressure Ibs Height, 



persq. in. =P. inches =H. H.P.-* 



3-358 



2-238 



I- 



6- 

 ii- 

 16- 



21' 



26- 

 31* 



36- 



56' 



658 

 467 



333 

 283 



183 

 100 



039 

 0-989 

 0-944 



4-90 



4-51 

 4-96 

 5-01 

 4'99 

 4-92 

 5-09 

 4-96 



4*85 

 4-80 



4'77 

 4*74 



5. At higher pressures, 1,000 Ibs. per sq. in. and upwards, the volume 

 of bagasse varied inversely as the 5th root of the pressure, or symbolically 

 HP- 2 = constant. Data of an experiment are given below, the results 

 being also expressed as a curve in Fig. 78. 



0.397 LBS. BAGASSE CORRESPONDING TO 120,000 LBS. OF 12 PER CENT. FIBRE CANE 

 PER HOUR IN 78-IN. MlLL, AT A SURFACE SPEED OF 25 FT. PER MIN. 



Pressure Ibs. 

 per sq. in. =P. 



83 

 162 



321 



480 



640 



703 

 H93 

 1595 

 2390 



3137 



3972 



4778 



5574 



6369 



7166 



798o 



8757 

 J 0347 

 11940 



Height, 

 inches =H. 

 1-79 

 i-io 

 0-845 

 0-67 



o-53 



0-52 



o- 50 



0-465 



0-42 



0-39 



0'37 

 0-36 



o-35 

 o-34 

 o-33 

 0-32 



0-3I5 

 0-31 



0-305 

 o- 30 



HP- 8 



3-97 

 2-65 

 2-37 



2-12 



90 

 8 9 

 90 



8 4 

 85 



86 

 82 

 91 

 90 

 '9 

 89 

 90 



93 

 97 



H 5 P 



983-0 

 131-0 

 73'7 

 43-o 

 21-7 

 24-7 

 24-2 

 24-7 



21- I 



21-7 



22-3 

 19-9 

 23-2 

 24-7 

 25-2 

 24-2 

 24-7 

 25-2 



26-5 

 29-7 



At higher pressures the volume of juice expressed from chopped cane 

 varied as the twentieth root of the pressure, or symbolically / P~ = con- 

 stant, where/ is the volume of the juice expressed.* 



*In my original publication I gave the volume as varying with the twelfth root. In commenting on these 

 results Bolk 8 observed that the twentieth root gives a much more constant value. 



