Production of hydrogen and carbon by solar thermal methane splitting. II. Room temperature simulation tests of seeded solar reactor

In the design of a solar thermal methane splitting reactor seeded with powder particles, care must be taken to prevent destruction of the reactor window by contact with incandescent solid particles. The method of screening the window by application of the tornado flow configuration (Int. J. Hydrogen Energy 28 (11) (2003) 1187) inside the reactor enclosure was studied experimentally by reactor flow simulation tests at room temperature. A secondary effect of the tornado flow pattern was identified during these tests. Friction between the swift jet of gas leaving the reactor enclosure in the axial direction and the surrounding relatively quiescent gas engenders a weak stream of gas along torroidal streamlines. Solid particles entrained by this secondary stream are carried towards the reactor window. An efficient gasdynamic method is described by which the above-mentioned negative effect is counteracted and eliminated. A solar reactor model of a special design was developed in order to enable demonstration of the effectiveness of the proposed method. Carbon black powder seeding tests were performed with this reactor model. Powder seeding conditions under which the reactor window is perfectly screened were determined by experiment.