Design Of Trombone Cooler For Gasses 5ru2y

Design of Trombone Cooler for Gasses Temperatures Highest Temp Lowest Temp Difference

Hot Fluid 200 C 100 C 100 C

Cold Fluid 80 C 30 C 50 C

LMTD=

R=

100 50

120−70 120 ln 70

( )

=2

Differences 120 C 70 C 50 C

= 90 C S=

50 170

= 0.3

From graph we find value of Ft Ft = 0.95

Corrected LMTD = 86 C

Heat duty to be removed =Q = 3.5 x 105 Kj/Hr 5

3.5∗10 4.19∗86

= 1670 Kj/Hr

Hot Fluid at Tube Side Taking 3-inch pipe of schedule 40 At = 0.00476 m^2

L = 2.4 m

Internal Diameter = 0.077 m Outer Diameter =0.089 m G = 3643/0.0047 = 7.8x105 Kj/Hr µ = 2 x 10^-5 Pa. s Re = 5.8 x 105

Mass flow rate of water required =

From graph Jh = 0.003 K = 160 By using equation Hi = 0.13 Hio = 0.13*0.077/0.089 = 0.112

Shell Side Calculations G = 1670/2*2.4 = 348 Taverage = 55 C µ = 0.00102 Kg/ms Re = 4G/µ = 6 x 10 ^ 6 From equation

Ho = 1020 Uc = 1020*0.112/(1020+0.112)= 102

Heat Transfer Area = Q/U Tlmtd A = 38 m2 Number of Tubes Required A/AtL = 38/ 0.716 = 53 tubes