Research Of CO₂Producton And Diffusion By Moulds In The Actual Warehouse Storage Of Grain

This thesis mainly studied under the condition of conventional storage,located at different levels of simulation in real storage of grain mildew pointsof CO2gas in the diffusion rule of grain heap, determine the grain heap cofcotheir breath of CO2gas concentration, mildew grain heap itself is analyzed andsimulated mildew points of CO2gas in diffusion law and the difference of theCO2gas in the grain pile tests than conventional food security method advanced,make the CO2gas test can better and more effective applied in grain storage mildewto change the location of the monitoring, effective method for grain securityin China.In conventional storage conditions, different grain varieties, and itsrespiration are very weak, the CO2gas concentration is low, in carries on thecontinuous25w testing found that grain heap less CO2concentration change asa whole. And mold activity of CO2gas can cause grain heap of elevated CO2concentration.CO2gas diffusion regularity in the grain pile with mildew point location ofdifferent change. Grain heap so long as has the mildew, the concentration ofCO2gas will rise. In longitudinal direction, mildew spot where maximum levelof CO2gas concentration change rate; CO2gas concentration of different levelsof the transverse direction, and decreases with distance mildew point distance,and mildew points in the level of CO2concentration change rate is the largest.Beyond a certain detection distance, whole grain bulk CO2gas diffusion rulesfor the lower layer> middle> upper.In real storage of grain, different amount of mildew and moisture content ofcases, mold activity of CO2gas concentration have great difference, but the CO2gas diffusion regularity in the grain pile did not change. Real storage of grain pests in activities can produce a large amount of CO2gas, by using CO2gas tests can accurately detect the grain heap pests activities.The metabolic activity of mold in grain storage will produce large amountsof heat, cause temperature rise of grain bulk. Traditional food temperature testdue to the relatively obvious lag, cannot timely, accurately reflect the safetysituation of grain storage. And CO2gas test by testing the mold activity of CO2gas, can accurately reflect the activity of microbes in grain storage. Such asmildew occurrence location of grain bulk temperature of40℃, CO2gasconcentration is2.216%, after2d of storage, mildew point2m distance testingpoint in the grain heap temperature is only23℃, and CO2gas concentration is0.158%.