IRSST - Institut de recherche Robert-Sauvé en santé et en sécurité du travail

Tower silo ventilation taking the chute into consideration


Fodder stored in conventional tower silos undergoes fermentation, a process that generates toxic gases at concentrations that could cause serious poisoning, possibly resulting in death. Due to insufficient oxygen and the presence of these gases, it is difficult to determine when the indoor atmosphere does not pose a hazard to workers. Since ventilation is the best means of ensuring the healthfulness of these confined spaces, the researchers documented in an initial study (Report R-672) the critical period in fodder fermentation and in the production of toxic gases when the doors between the chute and the silo are closed. They then formulated recommendations on the blowing ventilation time necessary to ensure good quality air in the fodder silo.

This time, at the request of the CSST, the scientists will adapt the previously developed analytical model to calculate the ventilation time necessary to ensure good quality air in both the silo and the chute, when the doors are open. They will thus obtain an analytical model for calculating the necessary ventilation time under such circumstances to obtain an acceptable air quality in both the silo and the chute. This information can be added to the information on the ventilation time necessary when the silo is completely closed, presented in the Guide sur la prévention dans les silos (Guide to prevention in silos), produced by the CSST, in collaboration with the UPA.