Development of evaporation equipment for reforming by spray flow

An experimental study was conducted in order to establish the thermal and fluid design criteria for a new steam reforming device, and a proposal was submitted to employ a flow laden with droplets (water and methanol mixture solution) directly impinging on a heated plate in the new reforming device. Experiments have been conducted by controlling spray impingement on a heated plate covered with a porous plate made by sintered metal. The new configuration of the reforming device is able to enhance the evaporation of liquid by using a low-level heat source held at lower than 600 K. Droplets atomized by a spray nozzle instantaneously evaporate on the heating surface without bouncing, since the sintered metal surface provides a higher Leidenfrost temperature due to surface roughness. The characteristics of spray flow and evaporation efficiency have been measured by Phase Doppler Anemometer which permits local measurements of size and velocity of liquid droplets, size distribution and mass flux of droplet. Results have confirmed that superheated gas was directly generated from the spray liquid with high efficiency, and the locations of heating plates and spray- nozzle were optimized. Finally the rate of evaporation was enhanced by pre-heating the liquid before atomization.