perancangan air disperser pada Spray Dryer perancangan nozzle pada Spray Dryer

Dipilih spesifikasi pipa Tabel 11 Kern, 1965 : IPS = 1 in Sch = 40 ID = 1,0490 in = 0,0266 m OD = 1,3200 in = 0,0335 m A = 0,8640 in 2 = 0,0006 m 2 Laju alir volumetrik F v : F v = mix ρ G = . , g am . , gm 3 = 3,247 m 3 jam = 0,000902 m 3 s Kecepatan aliran, v : v = A F v = , m 3 s , = 1,503 ms Bilangan Reynold, N Re : N Re = mix mix μ ID v ρ   = . , × , × , , = 73.709,06 turbulen 2100 Maka anggapan menggunakan aliran turbulen adalah benar. Spesifikasi nozzle standar Brownel and Young, 1959, App. F item 1 dan 2, hal.349 : Flange Nozzle thickness n = 0,2 in Diameter of hole in reinforcing plate DR = 2 in Length of side of reinforcing plate , L = 10 in Width of reinforcing plate , W = 12 58 in Distance, shell to flange face, outside , J = 6 in Distance, shell to flange face, inside , K = 6 in Distance from Bottom of tank to center of nozzle - Regular, Type H = 6 in - Low, Type C = 3 in 2. Nozzle Aliran udara Masuk Data perhitungan : Laju alir massa G = 20.354,956 kgjam = 5,654 kgs Densitas ρ udara = 0,616 kgm 3 Viskositas udara = 0,0289 kgm.s Dari persamaan 5.15, hal. 161. Coulson, 1983, sehingga diperoleh : di opt = 226.G 0,5 . ρ -0,35 = 226 x 5,654 0,5 x 0,616 -0,35 = 636,697 mm = 25,067 in Dipilih spesifikasi nozzle : OD = 25,625 in = 0,65 m ID = 24,981 in = 0,635 m Laju alir volumetrik F v : F v = ρ G = . , g am , gm 3 = 33.043,76 m 3 jam = 9,178 m 3 s  Nozzle Produk 3. Nozzle Aliran Produk MKP Data perhitungan : Laju alir massa G = 2.525,253 kgjam = 0,7 kgs = 0,7 kgs x 0,995 = 0,698 kgs Densitas ρ mkp = 2.338 kgm 3 Viskositas mkp = 0,001145 kgm.s Dari persamaan 5.15, hal. 161. Coulson, 1983, dianggap aliran turbulen. sehingga diperoleh : di opt = 226.G 0,5 . ρ -0,35 = 226 x 0,698 0,5 x 2.338 -0,35 = 12,5 mm = 0,492 in Dipilih spesifikasi pipa Tabel 11 Kern, 1965 : IPS = 12 in Sch = 40 OD = 0,84 in = 0,02134 m ID = 0,622 in = 0,0158 m A = 0,00211 ft 2 Laju alir volumetrik F v : F v = mix ρ G = . , g am . gm 3 = 1,08 m 3 jam = 0,0003 m 3 s Kecepatan aliran, v : v = A F v = , m 3 s , = 1,5 ms Bilangan Reynold, N Re : N Re = mix mix μ ID v ρ   = . × , × , , = 277.053 turbulen 2100 Maka anggapan menggunakan aliran turbulen adalah benar. Spesifikasi nozzle standar Brownel and Young, 1959, App. F item 1 dan 2, hal.349 : Flange Nozzle thickness n = 0,2 in Diameter of hole in reinforcing plate DR = 1 716 in Length of side of reinforcing plate , L = 10 in Width of reinforcing plate , W = 12 58 in Distance, shell to flange face, outside , J = 6 in Distance, shell to flange face, inside , K = 6 in Distance from Bottom of tank to center of nozzle - Regular, Type H = 4 in - Low, Type C = 3 in 4. Nozzle Aliran Udara + Umpan keluar Data perhitungan : Laju alir massa G = 20.354,956+220,810 + 18,424 +2.024,759 kgjam = 22.745,212 kgjam = 6,318 kgs Densitas ρ mix = 1 kgm 3 Dari persamaan 5.15, hal. 161. Coulson, 1983, sehingga diperoleh : di opt = 226.G 0,5 . ρ -0,35 = 226 x 6,318 0,5 x 1 -0,35 = 568,07 mm ID = 22,37 in Dipilih spesifikasi nozzle : ID = 22,37 in gambar F.5. Nozzle Reinforcing Plate H D 2 4 1 

g. Perhitungan berat pada Spray Dryer

a. Berat Shell

ID s = 8,202 ft = 2,5 m OD s = 8,238 ft H s = 7,835 m = 25,705 ft ρ steel = 489 lbft 3 Foust, App. D-10, p. 742 Berat shell = ¼.π.OD s 2 – ID s 2 .H s .ρ stell = ¼.π. 8,238 2 – 8,202 2 . 25,705. 489 = 5.839,83 lb

b. Berat Conis

ID c = 8,202 ft = 2,5 m OD c = 8,238 ft H s = 2,165 m = 7,1 ft ρ steel = 489 lbft 3 Foust, App. D-10, p. 742 Berat conis = 112 .π.OD c 2 – ID c 2 .H s .ρ stell = 112 .π. 8,238 2 – 8,202 2 . 7,1. 489 = 537,675 lb

c. Berat Atomizer

Volume Atomizer = = 0,00157 m 3 V c = 0,055 ft 3 ρ steel = 489 lbft 3 Foust, App. D-10, p. 742 Berat koil = volume koil x ρ steel = 0,055 x 489 = 27,11 lb

d. Berat Air disperser

OD c = 4,957 ft ID c = 1,5 m = 4,9212 ft H s = 0,3 m = 0,984 ft ρ steel = 489 lbft 3 Foust, App. D-10, p. 742 Berat air disperser = ¼.π.OD s 2 – ID s 2 .H s .ρ stell = 133,58 lb

e. Berat opening

 Berat nozzles Nozzle aliran F 11 : Ukuran Nozzle = 1 in Berat Nozzle = 4 lb fig.12.2. B Y, 1959 Nozzle aliran F 14 : Ukuran Nozzle = 0,5 in Berat Nozzle = 2 lb fig.12.2. B Y, 1959 Nozzle aliran F 9 : Ukuran Nozzle = 8 in Berat Nozzle = 30 lb fig.12.2. B Y, 1959 Nozzle aliran F 12 : Ukuran Nozzle = 8 in Berat Nozzle = 30 lb fig.12.2. B Y, 1959 Berat nozzle total = 2 + 4 +30 + 30 = 66 lb  Berat total opening Berat total opening = berat nozzle = 66 lb  Berat fluida dalam spray dryer Waktu tinggal = 6 s  Berat bahan baku Berat bahan baku = 4.789,246 kg 3600 x 6 s = 17,56 lb  Berat udara Berat bahan baku = 20.354,956 kg 3600 x 6 s = 74,63 lb  Berat total fluida Berat total fluida = Berat bahan baku + Berat air pendingin = 17,56 lb + 74,63 lb = 92,19 lb  Berat spray dryer Berat mati Spray dryer = berat shell + berat atomizer + berat air disperser + berat opening + berat fluida dalam spray dryer = 6696,385 lb = 3.043,81 kg

h. Perancangan Penyangga pada Spray Dryer

Berat untuk perancangan = 1,2 x berat mati Spray Dryer = 1,2 x 6696,385 lb = 8.035,662 lb m Spray Dryer dengan 4 kaki. Kaki penyangga dilas di tengah – tengah ketingggian 40 dari tinggi total Spray Dryer . Gambar F.6. Sketsa sistem penyangga Spray Dryer a h L 2 5 H t bp