• Table of Contents
• Introduction
• Plant Data
• Electrolyte Properties
• Concentration Converter
• Cell Voltage
• Alumina Feeding
• Anode Table Layout

• Table of Contents
• Introduction
• How to Use AlPrg
• Plant Data
• Alumina Feeding
• Electrolyte Properties
• Cell Voltage

• Table of Contents
• Introduction
• ATab Version 2
• Layout-View
• Evaluation-View
• 3D-View
• Floating Windows
• Optimization Window
• Examples
• Downloads

• Table of Contents
• Principles Hall-Héroult
• Mass Balance
• Electrolyte Properties
• Cell Voltage
• Energy Balance

• Current Efficiency

• Raw Materials

• Cell Operation

• Measurements

• Environment, Emissions
• Examples, Exercises
• Literature

• News and Events
• Name Index
• Subject Index
• Sitemap
• Recreation

Interactive Web Page and PC Program

The Hall-Héroult electrolysis process consumes its carbon anodes and consequently the old used anodes have to be replace after some time period. This time period is usually about 25 days depending on the size and quality of the anodes and on operational parameters like the intensity of the electric current. This anode change is executed according to a defined schedule in order to eliminate cell disturbances caused by the changing operation.
You study the behavior of the anode table during and anode change cycle period either with an interactive webpage:

Anode Table Interactive Web Page

On this web page you set the anode numbering layout and the anode change schedule. You observe the behavior of the anode table during an anode change cycle period.

or with a PC program (ATab) that you may download:

ATab PC Program

Compared to the interactive web page you can in addition evaluate the anode change pattern according to several criteria. The goal is to find an optimal way to change the anodes

Evaluation

During their lifespan in the electrolytic cell the anodes decrease their height and surface area decrease. Consequently other values of the anode table will change during the anode cycle time like the weight distribution, the height and surface difference of adjacent anodes. These changing parameters affect among other things the load distribution of the anode beam, the cover of the anodes with crushed bath or alumina i.e. the protection of the anodes against air attack and the distribution of the electric current.
ATab evaluates these parameters (distance anodes, load distribution, height and surface differences, etc.) not only for a momentary situation but also over the entire cycle period to assess a selected anode numbering schema and anode change pattern.

Optimization [ Lit.]

There are obviously a lot of ways to number the anodes and to assign changing patterns. It is also evident that is too time consuming to evaluate this vast amount of possible anode table layouts by numerical model calculations or pot room trials. A solution is to determine for each layout key values and to use these parameters to select promising layout candidates.
This method reduces the amount of numerical calculation but still 3'628'800 layouts must to be examined for the case of an electrolytic cell with ten anodes in other words 10! = 3'628'800 permutations must be treated. ATab solves this problem by dividing this task into several steps with less calculation work.