Preparative Chromatography - Alternative Preparative Techniques > The Simulated Moving Bed Preparative Chromatography System > Page 57
Figure 29. The Multi-Column Simulated Moving Bed Column
The disc was constructed from two thick steel discs, the lower disc carried the connections to the columns and the upper disc carried the connections to the different inlet and outlet ports. The lower disc was assembled on a steel framework to provide support for the columns. The upper disc, was thus free to rotate and, when programmed correctly, could simulate the moving bed.
The disc was fairly complex in design and contained many sliding surfaces all of which had to be leak proof when under considerable external pressure. Nevertheless, it could be constructed relatively simply when compared with the complex construction of Barkers large wheel device. Using appropriate surface grinders and lapping procedures, despite its size the disc valve could be made leak proof even when under hydraulic pressure when used for liquid chromatography separations.