CONTENTS DESIGN PROBLEM INTRODUCTION FLOW CHART OF DESIGN NECESSARY RELATIONS PROPOSED DESIGN CONCLUSIONS BIBLIOGRAPHY

DESIGN PROBLEM Design a shell and tube heat exchanger for heating 370 tons/hr of crude oil (sp gr. of 0.826 at 15 C and normal boiling point 241 C) from 65 C to 90 C using kerosene (sp. gr. 0.81 at 15 C and normal boiling point of 193.5 C) available at a temperature of 150 C. Choose the flow rate of kerosene so that it does not vaporize

INTRODUCTION Most versatile type of heat exchangers Applications - Process industries, Conventional and nuclear power stations Provide relatively large ratios of heat transfer area to volume Used in many alternative energy applications including ocean, thermal and geothermal 2. Used in process industries where heat exchange is in between liquids and heat transfer coefficient is high

DESIGN FLOWCHART

TO CALCULATE UNSPECIFIED W ASSUMING T MAKE ENERGY BALANCE TO CALCULATE UNSPECIFIED W ASSUMING T COLLECT ASSUME OVERALL COEFFICIENT Uo(52 – 88) btu.ft-2. . F-1 Decide upon the no. of Shell and tube passes, ΔTlm,Ft Calculate Area Ao = [Q / (Uo * ΔTm )]

DECIDE TUBE SIZE,LENGTH CALCULATE No, TUBES, SHELL DIAMETER ESTIMATE TUBE SIDE HEAT TRANSFER Coef. --------------- 1 DECIDE BAFFLE SPACING AND SHELL SIDE HEAT TRANSFER COEFFICIENT ---------------- 2 CALCULATE OVERALL HEAT TRANSFER Coef INCLUDING DIRT FACTORS --------------- 3

NO YES CALCULATE TUBE SIDE SHELL SIDE Pre DROPS --------------- 4 WITH IN SPECIFICATIONS ? NO YES

In the present situation the max allowable Pressure drop is 13.48psi SUCCESSFUL DESIGN If the Shell side Pressure drop comes out to be less than the maximum Allowable pressure drop then there is no vaporization of Kerosene In the present situation the max allowable Pressure drop is 13.48psi The Pressure drop calculated using our design comes out to be 12.72 psi

RELATIONS ------------------- 1 --------- 2 ------------------- 3

RELATIONS

Results Hio=88.48 BTU/ft-2 F-1 Ho = 320.62 BTU/ft-2F-1 Uo(assumed) = 53 BTU/ft-2F-1 Uc (Clean Coefficient) = 69.34 BTU/ft-2F-1 Uod (calculated) = 57.40 BTU/ft-2F-1 Error = 8.3 %(within tolerance) ∆Ps = 12.72 psi ∆Pt =12.19 psi

Proposed Design 1 Shell pass,2 Tube Pass(1-2 Heat Exchanger) Length of the Tube = 30 feet Number of tubes = 822 Tube O.D = 0.75” Triangular Pitch = 0.9375” Tube Inner Diameter = 0.56” Shell inner Diameter = 31” Baffle Spacing = 17” Overall Heat Transfer Coefficient = 57.40 BTU/ft-2F-1

Conclusions Pressure Drop results – less than the maximum allowable Pressure drop for this Equipment Heat exchanger dimensions suggested – within the range used as thumb rules in Industry Heat Transfer Area can be increased – Put more Tubes, use finned-tube Heat exchanger Satisfactory Design was proposed

Bibliography Kern, Donald Q., “Process Heat Transfer” Ludwig, Ernest E., “Applied Process Design for chemical and petrochemical plants”, vol.3, Ed.3. Ozisik, Nekati M., “Heat Transfer” Perry’s Chemical Engineers’ Handbook. (software edition)