Within Électricité de France (EDF) hydroelectric power stations, IGCBoxes are industrial mini PCs dedicated to industrial process data archiv-ing. These equipments expose distinctive features, mainly on their storage system based exclusively on flash memory due to environmental constraints. This type of memory had notable consequences on data acquisition performance, with a substantial drop compared with hard disk drives. In this setting, we have designed Chronos, an open-source NoSQL system for sensor data management on flash memories. Chronos includes an efficient quasi-sequential write pattern along with an index management technique adapted for process data management. As a result, Chronos supports a higher velocity for inserted data, with acquisition rates improved by a factor of 20 to 54 over different solutions, therefore solving a practical bottleneck for EDF.