DESIGN OF SHELL-SHELL-TUBE TYPE HEAT EXCHANGER

摘要

IT IS COMPLETELY A NEW IDEA IN THE DESIGN OF SHELL AND TUBE TYPE HEAT EXCHANGER. THIS THEORETICAL DESIGN GIVES A WAY TO DESIGN THE COMPLETELY DIFFERENT TYPE OF HEAT EXCHANGER NAMED AS SHELL-SHELL-TUBE TYPE HEAT EXCHANGER (SSTHE). THIS DESIGN INCLUDES THE THERMAL AND MECHANICAL ASPECTS FOR THE DESIGNING OF SHELL-SHELL-TUBE TYPE HEAT EXCHANGER. THE SSTHE CONSIST OF A MAIN SHELL IN WHICH A NUMBER OF OTHER SMALL SHELLS ARE INTRODUCED AND THESE INNER SHELLS MHER CONTAIN THE TUBES. THE ONE FLUID IS INTRODUCED IN THE INNER SHELLS AND ANOTHER FLUID IS DIVIDED INTO THE TWO STREAMS, ONE IS FLOWING THROUGH THE OUTER SHELL AND ANOTHER THROUGH THE TUBES OF THE INNER SHELLS. THIS TYPE OF HEAT EXCHANGER IS ALSO KNOWN AS STTHE BECAUSE THE INNER SHELLS ACT AS THE TUBES FOR THE OUTER SHELL. HEAT EXCHANGE PROCESS IS THE BACKBONE OF EACH PROCESS INDUSTRY AND FOR THAT THEY USE NUMBER OF EXCHANGER IN SERIES WHICH HAVE HIGH CAPITAL AS WELL AS OPERATING COST AND THEY ALSO REQUIRES HIGH GROUND AREA TO INSTALL. TO OVERCOME THIS INDUSTRIAL PROBLEM WE INTRODUCE THE CONCEPT OF SSTHE. THE SSTHE CONTAINS THE ADDITIONAL HEAT EXCHANGE AREA BY THE INTRODUCTION OF SUB-SHELL/INNER-SHELLS WITHIN THE SAME SHELL AND TUBE HEAT EXCHANGER WHICH INCREASES THE OUTLET PRODUCT TEMPERATURE. SO THE NUMBER OF SERIES OF THE SHELL AND TUBE HEAT EXCHANGER CAN BE SUBSTITUTES BY THE SERIES OF LESS NUMBER OF SSTHE. THE TOTAL OPERATING COST FOR THE SERIES OF SSTHE IS LESS AS COMPARED TO SERIES OF SHELL AND TUBE HEAT EXCHANGER AS WELL AS THERE IS A DECREASE IN TOTAL CAPITAL COST 02 THE SERIES OF THE SSTHE AS COMPARED TO SHELL AND TUBE HEAT EXCHANGER SERIES. SO THE AIM OF THE DESIGNING OF SSTHE DESCRIBES THE ADDITION OF SUB-SHELL TO THE PREDESIGNED SHELL AND TUBE HEAT EXCHANGER TO INCREASE THE HEAT EXCHANGE AREA WITHOUT ANY DECREASE IN NUMBER OF TUBES. THE CAPITAL COST OF THE SYSTEM IS HIGHER THAN ONE SHELL AND TUBE HEAT EXCHANGER BUT IF THE SSTHE IS USED IN SERIES FOR HIGH HEAT TRANSFER THEY REQUIRES LESSER NUMBER OF SSTHE AS COMPARED TO SHELL AND TUBE HEAT EXCHANGER. THE ADVANTAGE OF THE SSTHE IS THE ADDITIONAL HEAT EXCHANGE AREA BY THE INTRODUCTION OF THE INNER SHELL AS WELL AS THE DISTRIBUTION OF ONE FLUID STREAM LEADS TO INCREASE THE OVERALL HEAT TRANSFER COEFFICIENT. BOTH THE FACTOR WILL GIVE THE HIGHER PRODUCT TEMPERATURE WITHIN THE SAME LENGTH THAT OF THE INDUSTRIAL SHELL AND TUBE HEAT EXCHANGER. AN ANOTHER ADVANTAGE OF THIS IS THAT IT HAS LOW FOULING AS COMPARED TO SHELL AND TUBE HEAT EXCHANGER DUE TO INCREASE IN AREA.