(US5298341-A)      A module is provided for an ion conducting device comprising a number of solid state ion conducting electrolyte elements arranged into a number of stacks with successive elements in each stack being in spaced parallel relationship by way of spacers, the stacks being in a circular array around a central plenum with a longitudinal axis. A number of longitudinal and transverse gas flow passageways are provided in the spaces between the elements and are generally aligned with the plenum. Transverse gas flow passageways radiate from the plenum and are in fluid communication with it.    A number of seals are placed between adjacent stacks of elements, and a pair of manifold plates are sealed against and sandwich the stacks and seals between them with a plenum aperture communicating with the plenum with gas flow apertures communicating with the longitudinal passageways. The stacks are connected in electrical series or parallel arrangement.    USE -   Fuel cells.    (JP6196197-A)      Module for an ion conducting device has solid state electrolyte elements (12) disposed in a generally circular array between end plates, e.g. (24B). Both plates have a central aperture (26), together with further apertures (28), each of which is associated with an element (12). Central space (14) communicates with passageways directed outwards through spacing members forming part of each element, and apertures (28) communicate with longitudinal passageways in the spacers. Seals (30)(32) are positioned between adjacent elements, which are also sealed to the end plates. The elements are connected together electrically, using either a series or a parallel arrangement.    Pref., each element (12) is a polymeric electrolyte membrane, an immobilised liquid membrane, or a molten electrolyte membrane, and four or six elements are arranged at regular intervals around end plate apertures (26). When used as a fuel cell, air is passed through space (14) via these apertures, and fuel gas is passed through apertures (28). When forming a stacked assembly, all apertures in adjacent end plates are aligned. For fuel cell use, the tiers are connected electrically in series or parallel. Elements (12) can also be of oxides of metals such as zirconium, cerium, hafnium, thorium and bismuth. Monolithic plates with surface gas flow grooves can also be used.    USE/ADVANTAGE -   Modules can be assembled to form a fuel cell. They can also operate as steam electrolysers or oxygen concentrators. The electrolyte elements are of relatively inexpensive materials, and flow characteristics of the module provide better performance and reliability than prior devices. The module is of compact size.