Evaporator apr 2013
-
Upload
wwtfproduction -
Category
Business
-
view
1.074 -
download
4
description
Transcript of Evaporator apr 2013
![Page 1: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/1.jpg)
Evaporation
•Evaporasi adalah …• Driving force = perbedaan titik didih cairan penyusun larutan
1
![Page 2: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/2.jpg)
Komponen Evaporator
1. Heat-exchanger 2. Vacuum 3. Vapour separator 4. Condenser
2
![Page 3: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/3.jpg)
FeedSteam (Saturated vapor)
Product
Condensate (Saturated Liquid)
Vapor Separator
Heat Exchanger
Vacuum for non condensable
Condensor
3
![Page 4: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/4.jpg)
Jenis-jenis Evaporator
1. Horizontal-Tube Evaporators2. Short-Tube (Calandria) Vertical
Evaporators3. Long-Tube Vertical Evaporators 4. Forced Circulation Evaporators5. Agitated Thin Film Evaporators
4
![Page 5: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/5.jpg)
Types of evaporators 1. Horizontal Tube Evaporator
Concentratedproduct
Vapour
Steam inlet
larutan encer
larutan pekat
steamkondensat
vapor
5
![Page 6: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/6.jpg)
Horizontal Tube Evaporators (lanjutan) Pipa-pipa pemanas horisontal tercelup
dalam larutan yang akan dievaporasi. Waktu tinggal lama
6
![Page 7: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/7.jpg)
Types of evaporators
Dilute feed
Condensate
Concentratedproduct
Vapour
Steam inlet
2. Short-tube (Calandria) Vertical Evaporators
7
![Page 8: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/8.jpg)
Steam mengalir dalam pipa-pipa HE, liquid di luar pipa-pipa.
Perbedaan densitas feed yang panas & dingin menyebabkan feed yang panas naik sementara yang dingin turun.(?)
Kevakuman menjaga agar titik didih larutan yang dievaporasi ...
Short-tube (Calandria) Vertical Evaporators lanjutan
8
![Page 9: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/9.jpg)
3. Long-tube Vertical Evaporators
Transfer panas baik Ada 2 jenis :
a. Climbing (Rising) film evaporatorsb. Falling film evaporators
9
![Page 10: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/10.jpg)
10
![Page 11: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/11.jpg)
11
![Page 12: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/12.jpg)
Steam terkondensasi di permukaan luar pipa-pipa. Feed yang mengalir dalam pipa-pipa mendidih
sehingga uap mengalir ke atas melewati bagian tengah pipa, sedangkan liquidnya membentuk lapisan tipis di dinding pipa.
Semakin cepat uap mengalir, lapisan liquid di dinding pipa semakin tipis dan bergerak semakin cepat, sehingga waktu tinggal produk semakin cepat.
Contoh : pada industri kertas, makanan, susu.
Climbing (Rising) film evaporators (lanjutan)
12
![Page 13: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/13.jpg)
b. Falling Film Evaporator
13
![Page 14: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/14.jpg)
Falling Film Evaporators(lanjutan)
Aliran liquid dalam pipa-pipa memanfaatkan gaya ...
Steam terkondensasi pada bagian luar pipa-pipa sehingga evaporasi lapisan tipis liquid menuruni sisi dalam pipa.
14
![Page 15: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/15.jpg)
15
4. Forced Circulation Evaporator
![Page 16: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/16.jpg)
Forced Circulation Evaporator (lanjutan)
Fluida dipompa dari ruang evaporator melalui steam pemanas.
Pemisahan vapor-liquid terjadi di ruang pemisahan.
Umpan encer ditambahkan ke sistem resirkulasi.
Waktu tinggal produk kemungkinan lebih lama.
16
![Page 17: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/17.jpg)
5.Agitated Thin Film Evaporator
17
![Page 18: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/18.jpg)
Agitated thin-film terdiri dari 2 bagian : tabung yang dipanasi & rotor.
Feed masuk tabung & terlempar ke dinding dalam tabung karena gerakan rotor yang memutar tabung.
18
5.Agitated Film Evaporator (lanjutan)
![Page 19: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/19.jpg)
Tipe evaporator Sifat feedbersih Kapasitas
besarSensitif suhu
viscous
Horizontal tube YaVertical short tube YaRising film Ya YaFalling film Ya Ya yaForced circulation Ya YaAgitated thin film Ya ya ya ya
19
Kriteria pemilihan evaporator
![Page 20: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/20.jpg)
Berdasarkan jumlahnya, evaporator dibagi menjadi 2 :1. Single effect evaporator
(hanya satu evaporator)2. Multi effect evaporator
(terdiri beberapa evaporator) a. forward feed multi effect evaporator b. backward feed multi effect evaporator
20
![Page 21: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/21.jpg)
Foreward Feed Multi Effect Evaporator
P >>T >>
P >T >
P <T <
Cond. Cond. Cond.
![Page 22: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/22.jpg)
P >>T >>
P >T >
P <T <
Cond. Cond. Cond.
Backward Feed Multi Effect Evaporator
![Page 23: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/23.jpg)
Multi effect Evaporator (lanjutan) • Temperatur steam evaporator I >>
evaporator II (maupun evaporator berikutnya).
• Agar vapor dari evaporator I berfungsi sebagai steam pada evaporator II (maupun evaporator berikutnya), boiling temperature bahan yang dipekatkan pada evaporator II harus << evaporator I dengan cara tekanan bahan yang dipekatkan pada evaporator II ... 23
![Page 24: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/24.jpg)
Foreward feed digunakan bila produk dapat rusak oleh T >> atau feed bersuhu >> (?)
Backward feed digunakan bila produk sangat viscous atau feed bersuhu << (?)
Backward feed memerlukan pompa karena harus memindahkan liquid dari P ... ke P ...
24
![Page 25: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/25.jpg)
Faktor-faktor kecepatan evaporasi1. Latent heat of vaporisation of feed 2. Total surface area of HE3. Beda suhu pelarut & zat terlarut4. Thermal conductivity of HE5. Thermal conductivity of feed6. Circulation rate in heat exchanger
25
![Page 26: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/26.jpg)
Neraca massa
26
Evaporator
F
P
V
(xA) F
(xA) P
![Page 27: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/27.jpg)
Neraca massa total :F = V + P
Neraca massa komponen terlarut :
(xA)F .F = (xA)P .P
27
![Page 28: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/28.jpg)
Di mana : F = feed (kg/jam) V = vapor yang terbentuk (kg/jam) P = produk (kg/jam) (xA)F = fraksi massa zat terlarut
dalam feed (xA)P = fraksi massa zat terlarut
dalam produk 28
![Page 29: Evaporator apr 2013](https://reader035.fdocuments.in/reader035/viewer/2022081414/54dc7e724a7959ef358b47b5/html5/thumbnails/29.jpg)
29
Contoh :Sebuah single effect evaporator digunakan untuk memekatkan larutan gula dari konsentrasi 10% menjadi 3_, _%. Larutan gula masuk evaporator dengan kecepatan 2 _ _ kg/jam. Tentukan :1. Banyaknya produk yang terbentuk
(kg/jam)2. Banyaknya vapor yang terbentuk
(kg/jam)