Experimental Investigation of the Heating Surfaces for Regenerative Air Heaters.

A newly designed heating surface for air heaters is tested, in laboratory conditions, in a wind tunnel. It consists of a dense layer of balls connected so as to form a grid. The grids are laid one upon another so that their ball nodes form a spatial checkerboard pattern. Grey-iron grids with 16. 5 mm ball diameters, and silumin grids with 8. 5 mm ball diameters, are tested. This arrangement ensures high thermal efficiency and good access for cleaning. It is found that the new heating surface can be practically applied only at moderate gas and air velocities - not higher than 2. 5-3. 0 m/s. Further research is needed to establish an optimum shape of the grids.