In order to study the air concentration distribution in the flow area near the solid bottom and walls of a chute, the length of a protective segment in response to a combination of bottom and lateral aerators with different heighttolength ratios was investigated through model experiments, and the sensitivity of the length of the protective segment of the aeration facility to the heighttolength ratio of the aerator was analyzed using the singleparameter sensitivity analysis method. The results show that, when the conditions of other factors remain unchanged, the length of the protective segment of the bottom aerator increases with the discharge and the heighttolength ratio of the bottom aerator, and increases slightly with the heighttolength ratio of the lateral aerator. The length of the protective segment of the lateral aerator increases with the discharge and, with the increase of the heighttolength ratio of the lateral aerator, it increases quickly at first and then slowly. Although the sensitivity of the length of the protective segment of the lateral aerator to the heighttolength ratio of the lateral aerator is higher than the sensitivity of the length of the protective segment of the bottom aerator to the heighttolength ratio of the bottom length, the heighttolength ratio of the bottom aerator is more important to the whole length of the protective segment of the aeration facility. The length of the protective segment can be effectively increased only when a reasonable combination of aeration facilities is used.