Worlds largest spiral element - history and development

In 2002, Koch Membrane Systems (KMS) embarked upon a project to produce a large-scale spiral membrane element. The purpose was to offer savings resulting from the increased scale of the target element. It was projected that these savings would be realized as the result of reduced number of piping connections, reduced foot print required for the plant, and ease of operation and maintenance from a smaller number of components. The plan was to use standard materials and design wherever possible. However, since the flow capacity and forces on the element are proportional to the square of the element diameter certain aspects of a standard spiral element had to be reviewed and alternatives selected. We discuss the choice of number and attachment of the component leaf units, the choices for the central core tube and inter-element connection system, and how the elements are supported within a multi-element housing against flow induced differential pressure. Finally we show how loading and handling issues dictated departures from traditional spiral element design. We present the results of in house and field testing to show how we were able to successfully meet each of our design issues resulting in a successful new product.