Abstract:

In the field of Chemical Engineering teaching, it is usual to find laboratory environments in which the experimental setups are limited either, by space, by the duration of the session or by the excessive cost of materials. These limitations generate labs where students are not able to explore all possibilities or variations of a system. The group of Educational Innovation of the Chemical Engineering Department of the University of Valencia is trying to meet these limitations by using small, simple and intuitive computer applications (applets) that reproduce the laboratory setups. These applets also allow to study the effect of parameter variations which, either on the characteristics of the experimental setup, either by time constraints, cannot be modified on the actual assembly (the volume of a reactor, the initial concentration, the heating power, the area of heat exchangers, the power or number of centrifugal pumps, the number of plates of a distillation column, etc.).

Until now, two applets have been already generated to simulate the experimental setups of Mass Balance and Energy Balance. The aim of the mass balance experimental setup is to obtain the variation with time of the concentration of a component in a stirred tank, in which a constant flow of water is introduced and from which an identical flow is extracted. The computer applet developed allows predicting this variation by solving the characteristic equations of the mass balance, and allows varying the volume of the tank, the initial concentration in the tank and inlet and outlet flows.

In the case of energy balance, the experimental setup consists of a perfectly adiabatic agitated tank with heating by electrical resistors and output overflow system that maintains a constant volume. The aim of this practice is to observe the evolution of temperature in the tank over time to a process of heating or cooling. In this case, the computer applet allows varying the volume of the tank, the initial temperature, inlet and outlet flow rates, and the heating power.

The visual interface of these applets incorporates a graphic area on which you can compare the evolutions obtained by modifying each parameter. The applets are installed in a computer next to the experimental setup, so that the student can use them to predict the experimental results while performing practice. Furthermore, the applets are also available for download, extending the horizons of the laboratory up to the student’s house.

In order to evaluate the usefulness of the implanted applets, user surveys have been conducted, which include technical aspects such as accessibility, usability or quality, and training aspects as the ability of these virtual environments to promote understanding of the mass and energy balances or the integration of the theoretical aspects in the laboratory. The applets have been well received by students, and have proven effective for understanding the mass and energy balances, as well as to understand other concepts such as the hydraulic residence time or the accumulation term. Using these applets promotes independent learning and is an attractive way for students to learn basic knowledge of chemical engineering. Moreover, the tool can be used in the first years of many degrees (Biotechnology, Chemical Engineering, Chemistry, etc.).

Keywords:

Innovation, applet, mass balance, energy balance, lab experiences, computer software on education.