The present study has been conducted to offer an geometrically optimal structure of a storage tank for a regenerator. In this paper, three kinds of baffle plates supposed to increase the regeneration rate and classified as "Type A($L^*$=0.25, 80(L)$ imes$300(W)$ imes$50 (H) [mm])", "Type B($L^*$=0.5, 150(L)$ imes$300(W)$ imes$50 (H) [mm])", and "Type C($L^*$=0.75, 230(L)$ imes$300(W)$ imes$50(H) [mm])" were suggested and tested. They were placed between the vertical C-C layers in the tank. Solution temperature and concentration were used to evaluate the regeneration rate. As a result, the regeneration rate was better in "Type C".