DESIGN OF SHELL AND TUBE DESIGN OF SHELL AND TUBE HEAT EXCHANGERHEAT EXCHANGER

BY-RAHUL OMARBY-RAHUL OMAR06166510200616651020B.TECH.F(CH)B.TECH.F(CH)

Heat Exchanger Includes Shell Tubes Working fluids

Heat Exchanger Shell More expensive to manufacture thantubes Material

Heat Exchanger Tubes Number of tubes Tube wall thickness Tube outside diameter Tube length Tube passes Tube material Tube layout Tube pitch

Heat Exchanger Tubes Number of tubes• Depends on flow rate & available pressure drop• Too many/few tubes Tube wall thickness• All tubes have standards Tube outside diameter• Small diameter means larger pressuredrop

Tube length• Typical lengths – 8, 12, 15, 20 ft. Tube passes• Number of times fluid moves from

one side of HE to other• The more passes the greater the

velocity

Tube material• Meeting requirements• Cost• Thermal properties Tube layout• Square Tube pitch

Heat Exchangers Fluids Viscous fluids belong on shell sidebecause usually improves heattransfer rate Fouling and erosion exist; highervelocity of fluid reduces build-up

Problem Statement

4500kg/hr of ammonia vapour at 6.7 bar 4500kg/hr of ammonia vapour at 6.7 bar pressure is to be cooled from 120pressure is to be cooled from 12000C to 40C to 4000C, C, using cooling water.The maximum supply using cooling water.The maximum supply

temp. of cooling water available is 30temp. of cooling water available is 3000C &the C &the outlet temp. is to be restricted to 40outlet temp. is to be restricted to 4000C.The C.The pressure drop over the exchanger must not pressure drop over the exchanger must not

exceed 0.5 bar for the ammonia stream & 1.5 exceed 0.5 bar for the ammonia stream & 1.5 bar for the cooling water. bar for the cooling water.