不同熏蒸方式下磷化氢的穿透、保持与散逸分析

Penetration,Retention and Dissipation of Phosphine Under Different Fumigation Methods

在整仓密封熏蒸和塑料帐幕密封分垛熏蒸条件下,测定了熏蒸空间以及烟箱内部磷化氢(PH3)的浓度,通过对不同熏蒸方式下熏蒸空间及烟箱内PH3浓度的动态变化比较,结合PH3熏蒸相关指标,分析了两种熏蒸方式的预期效果;在散毒过程中,测定了烟箱内部PH3的浓度,确定了瓦楞纸箱加塑料内衬包装方式下散毒的时间。结果表明:在相同的剂量下,采用塑料帐幕密封、分垛熏蒸处理烟箱内部PH3浓度高于整仓密封处理,且有效浓度维持的时间也较整仓熏蒸长,预期的熏蒸效果优于整仓熏蒸;在仓内温度>20℃的条件下,帐幕密封处理的烟箱内达到PH3有效浓度的时间早。对于瓦楞纸箱+塑料内衬包装的片烟,熏蒸过程需要9～10 d,而整仓处理的则需要11～12 d。另外,与整仓熏蒸相比,采取塑料帐幕密封和分垛熏蒸,药剂投放总量可减少1/2～2/3。

Two fumigation methods： in a sealed warehouse （Method I ） and in a sealed plastic tent （Method Ⅱ ） were compared. The phosphine （PH3） concentration in the fumigation environment and tobacco case was determined. Combining with the relative indexes of PH3 fumigation, the expectant effects of the two fumigation methods were analyzed by comparing the dynamic variation of PH3 concentration inside and outside tobacco case. During the process for PH3 dissipation, the PH3 concentration inside tobacco case was measured to determine the time necessary for dissipation of PH3 in a corrugated paperboard case with plastic liner. The results indicated that at the same dosage, Method Ⅱ was superior to Method Ⅰ in terms of the PH3 concentration and retention duration of lethal concentration inside tobacco case, and expectant effect. When warehouse temperature was 〉20 ℃, the PH3 concentration inside tobacco case in Method Ⅱ reached lethal concentration earlier than that in Method Ⅰ The durations of fumigation process for plastic liner corrugated paperboard case of Method Ⅱ and Method Ⅰwere 9 to 10 and 11 to 12 days, respectively. In addition, Method II reduced the total amount of phoSphine application by 1/2 to 2/3 comparing with Method Ⅰ .