Killing pests in granular food

摘要

Killing pests infecting a granular food (8) comprises pumping nitrogen with an oxygen content of < 3 (preferably < 7) vol.% through a mass of grains covered by a gas impermeable membrane (7). The gas pressure is 1-100 Pa above ambient. The nitrogen is produced on-the-spot by extraction from the atmosphere (1) and pumped through the grains. Oxygen-enriched gas (4) which remains after extraction of the nitrogen is recombined with the nitrogen (9) after the gas is pumped through the grains, so that there is no change in the composition of the air near the assembly. The nitrogen is generated by /- 1 gas separation membrane (3) and/or pressure swing absorption assemblies using active carbon granules. The gas impermeable membrane (7) is a plastic sheet and/or a metal foil. The membrane is preferably high-density polypropylene (HDPE), polypropylene (not stretched) (PP), or polyvinyl chloride (PVC) having a thickness of 10-100 mu m and with minimal oxygen permeability.