Overall Heat Transfer Coefficient of Reactor by huangyuarong

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									Overall Heat Transfer Coefficient of reactor



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Revision No                       1
Issued to download section on 27.05.12
    chemjunction.com
Calculation of heat transfer coefficients in agitated vessels:
Cooling with water:
Data:
Vessel data:
Material of construction:                SS316
Inner diameter of the vessel, Dv :            2450   mm             [STD. GCL 15.7 KL Reactor]
                                              2.45   m
Wall thickness of vessel,t :                    10   mm
                                              0.01   m
Thermal conductivity of SS316 =                9.4   Btu/ft.h.°F
                                           13.9872   Kcal/h m K
Dirt resistance :-
Inside vessel, Rdi :                       0.0006 h ft2 °F/Btu
                                         0.000123 h m2 K/Kcal
Jacket side [water], Rdj :                 0.0013 h ft2 °F/Btu
                                         0.000266 h m2 K/Kcal

Jacket data:
          Type:                          Limpet (Half-pipe coil type)
          Coil Diameter, Dc :                 2650 mm
                                              2.65 m
           Inner pipe diameter, di :            82 mm
                                             0.082 m
           Equi. Diameter, De= pdi/2 :    0.128857 m

           Medium:                               Water
           Temparature:                        35 °C
           Flow rate:                          18 m3/Hr
           Flow area:                    0.002642 m2
           Velocity, v:                      1.89 m/s
           Density, r :                         1 g/cm3
                                             1000 Kg/m3
           Viscosity, m :                   1.000 cp
                                            0.001 Pa.s
           Thermal conductivity, k :        0.363  Btu/ft.h.°F
                                            0.540 Kcal/h m K
                                          0.00015 Kcal/s m K
           Specific heat, C :                   1 Kcal/Kg K


Vessel fluid data:
Name of the fluid :                               MCB
Temparature:                                    75 °C                         A
Density, r :                                  1.08 g/cm3                      B
                                             1080    Kg/m3
Viscosity, m :                              0.445    cp                       Temp °C
                                         0.000445    Pa.s                           10
Thermal conductivity, k :                  0.0476     Btu/ft.h.°F   [Perry]         75
                                           0.0709    Kcal/h m K
                                         1.97E-05    Kcal/s m K
Specific heat, C :                           0.35    Kcal/Kg K
Agitator data:
Type :                                               Pitch-blade turbine
Sweep                                                      40 %
Diameter, Da :                                            980 mm
                                                         0.98 m
Speed, N                                                   70 rpm
                                                         1.17 rps
                                         Tip speed :     3.59 m/s

Heat transfer coefficients:
Vessel side heat transfer coefficient:
For Agitated vessels without internal coils:
           Nu = 0.62 Re(2/3) Pr(1/3) (m/mw)0.14
                        Ref: Chopey, pg.7-28)

                           Nu = h Dv / k                24071
                           Re = Da2 N r /m            2719404
                           Pr = C m / k                   7.9


Heat transfer co-efficient inside the reactor =           696 Kcal/h m2 K

Heat transfer coefficient inside limpets (Half-pipe coil jacket):
For half-pipe coil jacket:
            Nu = 0.027Re0.8 Pr0.33 (m/mw)0.14(1+3.5De/Dc)
                           (Ref:Chem.engg.,90,vol.106,1,1999)

                           Nu = h De / k                 1206
                           Re = Dev r /m               243902
                           Pr = C m / k                   6.7

Heat transfer co-efficient, hj =                     5054.117 Kcal/h m2 K

Wall Resistance, Rw : l/k                            0.000715 h m2 K/Kcal
                                                      1398.72 Kcal/h m2 K

Heat transfer co-efficient inside the reactor(hi) :                      696 Kcal/h m2 K
Jacket side heat transfer co-efficient (hj) :                           5054 Kcal/(Hr*m²*°C)
Wall resistance (Rw) :                                           0.000714939 (Hr*m²*°K)/ Kcal
Total dirt factor (Rd) :                                         0.000389235 (Hr*m²*°K)/ Kcal
(Overall heat transfer coefficient)-1 :                         0.002738547 (Hr*m²*°K)/ Kcal
Overall heat transfer coefficient (Ud) :                                 365 Kcal/(Hr*m²*°C)


Power Requirement:

Agitator details              Np           No.        Total
Pitch-blade turbine(45°)           1.5           2          3
Anchor                             0.6           1        0.6
                                                          3.6
FHP :   5581 W
        7.48 HP
BHP :   8.80 HP
 vessels:



GCL 15.7 KL Reactor]




            -1.70701      Temp °C         m cp
            471.8691             75 0.444988619

              m cp      C Kcal/Kg K   k Btu/ft.h.°F
                0.911          0.298       0.083
                0.445           0.35 0.047616821

								
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