Prosyma Research Ltd report to Plastics (Manchester) Ltd.

S F Bush

Introduction

Plastics (Manchester) Ltd wish to supply 3 mm thick thermoformed polypropylene cladding to cover 40 mm of rock wool insulating stainless steel tanks. The tanks are suspended by 70 mm x 70 mm x 5 mm carbon steel box sections welded to the tank and attached to a frame.

Over most of the area to be covered by the PP cladding its temperature will be close to atmospheric by virtue of the rock wool insulation. However, where the suspending box sections emerge from the rock wool, it may be expected that the temperature in the steel will be significantly above this. Because the small gap between the PP cladding and the steel box section is to be filled with a silicone sealant, the PP will be in local thermal contact with the steel.

The objective of the following calculations is to establish the temperature at the steel/sealant/PP contact point. As will be seen, this temperature is strongly affected by wind flow around the tank and over the suspending box sections. Without measurements of these flows only very approximate estimates can be made.