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LAMPIRAN APERHITUNGANA.1 Perhitungan % Berat Air AwalPada cawan penguapBerat sampel basah (Wb): 50,41 gramBerat sampel kering/ konstan (Wc): 38,53 gramMaka berat air di pasir mula-mula adalahA.2 Penentuan Kecepatan Pengeringan Berdasarkan PercobaanTray kosong (WT): 0,3497 KgTray + pasir basah (Wm): 0,9497KgPasar basah: 0,6Luas Tray (A): 0,0495Suhu udara kering (Tg): 30,352 CSuhu bola basah udara pengering (Tw): 40,064 CLaju alir udara pengering u1: 0,695 m/s A1: 0,0484 m2A2: 0,784 m2x: 0,00733 m
Tabel A.1 hasil pengamatan
No RunSuhu Bola Basah (C)Suhu Bola Kering (C)Laju Alir (m/s)Berat Sampel + Tray (Kg)
0---0,946
127320,680,946
228,3333,660,710,945
329370,750,943
429,66380,750,942
530,6640,330,680,940
630,33410,670,938
730,6642,330,690,936
83142,330,70,934
93142,330,680,931
1031,33410,680,930
1131420,680,928
123141,660,690,925
1331,33410,680,923
1431,33430,690,921
1531,6643,330,70,92
Contoh perhitungan.Pada menit run ke 2 dan ke 3, menit ke 10X2 = = = 0,339X3 = = = 0,335
X = X3 X2 = 0,335 0,339 = -0,004Nc = Nc = = 0,4724 kg/m2jam
Tabel A.2 Laju pengeringan nowaktu (jam)massa pasir + tray (kg)pasir basah (kg)kadar air Xlaju pengeringan
`100,9460,5970,3420
20,0833330,9460,5970,3420560
30,1666670,9450,5960,3398080,18163953
40,250,9430,5940,3353120,472440945
50,3333330,9420,5930,3330640,236220472
60,4166670,940,5910,3285680,472440945
70,50,9380,5890,3240720,472440945
80,5833330,9360,5870,3195760,472440945
90,6666670,9340,5850,315080,472440945
100,750,9310,5820,3083360,708661417
110,8333330,930,5810,3060880,236220472
120,9166670,9280,5790,3015920,472440945
1310,9250,5760,2948480,708661417
141,0833330,9230,5740,2903520,472440945
151,1666670,9210,5720,2858560,472440945
161,250,920,5710,2836080,236220472
A.3 Penentuan Kecepatan Pengeringan Berdasarkan TeoritisA1= 22 x 22 cm = 484 cm2 = 484 x 10-4 m2 A2= 28 x 28 cm = 784 cm2 = 784 x 10-4 m2 Tg= 40,06oC = 313,06 KTw= 30,35oC = 303,35 K Tf= (313,06 +303,35) / 2 = 308,205 K
= 1.8879 .105 kg/m.s = 1,148 kg/m3Cp= 1004,8 J/kg.KNPr= 0,7058 (Appendix 4.3-3, Geankoplis)Konduktivitas pasir = 0,25 W/m.KPanjang Dryer (L) = 2,89 mLaju Alir U1= 0,695 m/sU2 = = 0,429 m/sNRe = = = 1,221 x 105NNu = 0,664 x (NRe)0,5 x (NPr)1/3 = 0,664 x (1,221 x 105)0,5 x (0,7058)1/3= 221,64