Manufacturing Technology Today

M. Ravi Kumar ¹, P. Srinivas ¹, M. Madhavi ¹

Affiliations
1 Dept of Mechanical Engg., M. V. S. R. Engineering College, Nadergul, Hyderabad, IN

Abstract

Advanced composites with their inherent advantages such as strength to weight ratio, became an ideal choice mostly in the fields like aerospace, missiles, submarines and ground structures like heavy military bridges etc. Composite materials also proved to be good insulators and have wide application in boiler tubes, heat exchanger shells and electrical applications. In any power plant apart from the turbine, boiler and pump, the heat exchanger is a vital component. The present investigation proposes EGlass/Vinyl Ester filament wound FRP (Fiber Reinforced Polymer) heat exchanger shell due to its good thermal insulation and noncorrosive properties. Experimental investigation was carried out to determine thermal conductivity on FRP shell. Based on these investigations, a single tube & shell type heat exchanger with copper as tube and FRP as shell is designed and developed in order to carryout performance analysis of a composite shell for both parallel and counter flows for a range of temperatures from 40 °C to 150 °C. The heat exchanger effectiveness for FRP shell is found to be 28% more than mild steel shell in the heat exchanger. The present study recommends that the existing metal boiler shells can be replaced with FRP material due low maintenance cost and less radiation effect.

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M. Madhavi ¹, K. Rama Swamy ², K. V. J. Rao ³, K. Narayana Rao ⁴

Affiliations
1 Dept. of Mechanical Engg., M V S R Engg. College, Hyderabad, IN
2 Defense Research & Development Organization, Hyderabad, IN
3 St. Peter’s College of Engineering, Hyderabad, IN
4 AICTE, New Delhi, IN

Abstract

Composite pressure vessels developed by filament winding technology falls into two categories i.e., pressure vessels with equal pole openings & unequal pole openings. Usually composite pressure vessels with equal pole openings can be developed with geodesic paths. Geodesic lines connect two points along the shortest distance over the surface. In this case no friction force is required to keep the fiber from slipping, since it follows a self-stable trajectory. There are, however situations where it is not possible to place fibers, at least in some region of the mandrel, on the geodesic curve. It implies that we have to resort to modified helical winding (non-geodesic) at cylindrical portion or dish ends or both. A composite pressure vessel like CRMC (composite rocket motor casing) with unequal pole opening is an example of this. In the present study, a composite pressure vessel with unequal pole openings considering deviation from the geodesic path only on the cylindrical portion is designed, developed and tested for burst pressure. The shell is subjected to uniform internal pressure and the conditions of thin walled structure and balanced symmetry winding pattern with carbon T300/Epoxy are considered.

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