The purpose of the lab was to evaluate different metals in search of determining the best piping material for a chemical reactor created by Kauffman Enterprises. The reactor vessel is to be made out of stainless steel and will operate at 525C while containing highly corrosive hydrochloric acid. The primary metals that were evaluated were aluminum, brass, copper and stainless steel. The initial lengths of the rod were taken first, then they were placed into a heat exchanger apparatus where their initial temperature was taken by a thermometer. This apparatus was then hooked up by a hose to a steam generator to cause expansion of the metal rods. This caused a change in length and change in temperature which was recorded by a micrometer and thermometer respectively. The engineers used the change in length, initial length, and change in temperature to determine the metal’s coefficient of linear expansion. The researchers also had to take the cost and corrosion resistance of each metal into account when determining the best material for the pipes. The researchers were able to determine that the copper pipe was the best piping material for the reactor. This material had the second lowest coefficient of expansion, a low material cost, and no corrosion effect.

Introduction and Background

Kauffman Enterprises has hired a group of University of Iowa engineers who are knowledgeable in materials science to work on a chemical reactor being designed by the company. The reactor vessel that will be operated at 525C and will contain highly corrosive hydrochloric acid. The reactor will be created with stainless steel, but a significant amount of piping attached to the reactor will be needed. The job for the engineers is to determine the best material for the piping given four options of: Brass, Copper, Aluminum and Steel. The recommendation will take into account the expansion of the pipes, corrosion resistance and cost.

Since the process will be operated at 525C, there will be some type of expansion with the piping material. Each material that will be tested has a unique coefficient of linear expansion, and this is a property that indicates how much that material will expand when heated or retract when cooled. This coefficient is used in many engineering projects to determine how much stress a material can handle when heated or cooled. These types of stresses can lead to cracking or even deformation of the material depending on the temperature. To calculate this coefficient, you will need to apply the equation:

Figure [1]. Coefficient of Linear Expansion Formula (Kauffman)