Study On The Concentration Of The Methyl Bromide In A Container At Lower Temperature And The Comparison Of Different Goods

A 40-feet carton was fumigated with methyl bromide at 5-15℃to study its concentration change and distribution in this container. In addition, three kinds of exported goods, the grain, feed and wood were chosen as research targets to demonstrate the effect of different physics property of goods to the distribution of the methyl bromide.By research on the concentration change and distribution of methyl bromide in the container, we found that in the first period of fumigating, the absorption of the goods to methyl bromide became quickly, so did the concentration decline of the fumigant because of leakage of the carton itself. The distribution of the fumigant is not uniform in the aclinic and vertical directions. The absorption of the goods to methyl bromide completed after 6 hours delivered the gasified fumigant and the distribution of the concentration in space got balance. Therefore, it was made that the detected concentration after 6 and 24 hours delivered the fumigant were higher than 70% and 50% of the fumigant dose as the detected criteria. And the concentration we detected was much higher than that detected in fumigated tent as well as the period of the fumigant got uniform in space in terms of its concentration distribution was shorter, the accumulated CT values in every detected position agreed with the request of the quarantine.It was found that the goods with different physics property indeed affected the concentration distribution of the methyl bromide. In terms of the three goods, the concentration balance in the grain and feed obtained in aclinic and vertical directions after 6 hours delivered the gasified fumigant, while the wood needed 6 hours. The absorption degree of the three goods to methyl bromide was: feed > grain > wood.