平房仓气密性改造对氮气储粮应用效果的影响

The effect of the air tightness renovation of horizontal warehouse on the application effect of nitrogen stored grain

通过对2个试验仓的仓墙、仓门、通风口等易漏气部位进行气密性进行改造,粮堆采用“六面封”,实施氮气气调作业。采用负压法测定压力半衰期,检测粮堆氮气浓度,检查虫害致死情况,测算氮气储粮费用,对仓房气密性、氮气杀虫效果、储粮成本进行对比分析。结果表明:在改造后,仓房气密性达到气调储粮标准,甚至超过了一级气调标准;氮气浓度保持在98%以上的天数超过28 d,对磷化氢有抗性的储粮害虫可全部杀死,而有效浓度天数达不到的仓房,个别部位仍有谷蠹活动;仓房的气密性越好,储粮的成本越低,气密性超过一级气调标准的仓房,氮气储粮成本甚至低于磷化氢熏蒸,由此可见,气密性是决定氮气储粮成本的关键因素。

The air tightness of the wall,door,vent and other parts prone to air leakage of the two test warehouses was reformed.The grain was sealed in six-Side with polyvinyl chloride film.The method of nitrogen controlled atmosphere was applied.The negative pressure method was used to measure the half-life of pressure,detect the nitrogen concentration of grain pile,check the death of insect pests,calculate the cost of nitrogen grain storage,and compare and analyze the air tightness of warehouse,the insecticidal effect of nitrogen and the cost of grain storage.The results showed that the air tightness of the warehouse reached the standard of grain storage by air conditioning,and even exceeded the first-level air conditioning standard.When nitrogen concentration was kept above 98%for more than 28 days,all the stored grain pests resistant to phosphine could be killed.In the warehouse where the effective concentration was less than 98%for more than 28 days,the Rhyzopertha dominica was still found in some parts.The better the air tightness of the warehouse,the lower the cost of grain storage.The air tightness of the warehouse exceeded the first-level air conditioning standard,and the cost of grain storage with nitrogen was even lower than phosphine fumigation.Therefore,air tightness was the key factor determining the cost of grain storage with nitrogen.