Food-grade inert powder aerosol insecticidal technology is a technology in which aerosolized inert powder is driven by a fan to be evenly distributed in the voids of the wheat grain pile in the form of a gas-solid two-phase flow. This paper discusses that the inert powder is evenly distributed on the grain feed conveyor while the bulk wheat is fed into the silo, so that the inert powder aerosol is evenly distributed in the gap of the grain pile. The results show that the application of inert powder aerosol has a better pest control effect. At the same time, after the inert powder aerosol was applied to the wheat that was put into the warehouse, no live insects were found from August 2017 to August 2018. Wheat grains without inert powder aerosol for pest control In early August 2018, Indian grain moths appeared on the grain surface. Food-grade inert powder aerosol is a green stored grain pest control technology with good application prospects. Keywords: inert powder; prevention and control; stored-grain pests; real warehouse applications. Today, food safety requirements are becoming more and more stringent. Food advocates organic, green, safe and assured food. It must be controlled from the source, and there is no pollution in the whole production process. In the process of storage, it is necessary to control and reduce the number of fumigation and insecticides of toxic chemicals, so as to reduce the residue of toxic chemicals. The promotion of green grain storage grade inert powder aerosol technology is the current green grain storage technology. In the aspect of insecticide prevention and control of stored grains in my country, chemical fumigants such as aluminum phosphide and insecticide are the mainstays. Although after decades of continuous screening, the agents that are highly toxic to the human body and have many residues are gradually being eliminated, but they are highly effective and low-toxic. The drug is still toxic to the human body, and the drug residues are still serious to the food pollution, causing pollution to the environment and causing certain harm to the human body, and there are also serious safety hazards during the use process, and safety accidents occur from time to time. With the use of pesticides for fumigation and insecticide for decades, stored-grain pests have developed a certain resistance to commonly used pesticides, so that the dose of pesticides has to be increased. Sometimes the same batch of wheat grains is used multiple times during the five-year storage period, and the pesticides are frequently used. Drug residues increase due to medication. In view of the increasingly serious problem of chemical pollution, it is particularly important to propose scientific and green grain storage in a timely manner. Grain storage technology must develop in the direction of green, healthy, environmental protection and low-carbon. The technology of chemical fumigation to prevent and control insect pests has attracted the attention of scientists across the country. In this experiment, in the dry climate of Xinjiang, the effect of using inert powder to prevent insects.

1. Food-grade inert powder (silica) is a food additive that has insecticidal effect and meets the requirements of GB25576, and is used as an anticaking agent for raw grains in accordance with the recommended addition amount of GB2760, and is a substance used to kill insects in grain piles. The main component of the inert powder is (SiO2•nH2O), which has small particles. The molecular size of more than 99% of the silicon dioxide is about 0.5m, the density is about 0.2g/cm3, and the specific gravity is low. Studies have found that the food-grade inert powder has both physical insecticidal and anti-insect effects.

2. The insecticidal mechanism is that the inert powder affects the activity of the insect membrane, causing the limbs and antennae to be unable to move, leading to the final death of the pests. In the book "Horizontal Technology of Grain Storage", there are five hypotheses about the insecticidal mechanism of inert powder. 1. The inert powder particles block the air valve, causing the insects to suffocate and die. 2. The inert powder particles are embedded on the epidermis, causing the worm's epidermal scratches to lose excessive moisture and die. 3. Inert powder absorbs moisture on the surface of insects. 4. Insects and mites die due to ingestion of inert powder particles. 5. The inert powder absorbs lipids in the upper epidermis of arthropods and destroys the epidermis, causing excessive dehydration or drying of the insect body. The insecticidal mechanism of inert powder aerosol needs further research, but as a new type of environmentally friendly physical insecticide, its effect is remarkable.

Three, usage and dosage

The scope of application of inert powder is in accordance with the provisions of "National Food Safety Standards and Food Additives Standards" GB2760. SiO2 can be used as an anticaking agent in raw grains, and the maximum allowable amount is 1.2g/kg. It is used to prevent and kill insects in stored grain, and the dosage is 4mg-20mg per kilogram. Inert powder is used to prevent and control stored grain pests. It can be sprayed through grain ventilation pipes to form aerosols. The spray on the grain pile is carried out by suction with the pipe at the bottom of the grain pile. It can be sprayed in an empty warehouse, insect-proof threads, surface mixing of grain piles, partial treatment of grain piles, and surface treatment of packed grains, etc., are required to be evenly mixed.

Fourth, the application of inert powder storage grain pest control

The company uses wheat to rotate new warehouses and chooses a 5,000-ton standard warehouse with a span of 21 meters, a length of 54 meters, a beam bottom elevation of 7.8 meters, and a grain stacking line of 6 meters. Use inert powder to prevent insects, combined with grain entering the warehouse, spray inert powder on the conveyor to prevent insects while feeding the grain. Calculate according to 20mg/kg to determine the whole warehouse dosage, and spray the dosage evenly. The economy is normal, and the amount of inert powder is 100 kg.

Five, the problems encountered during the experiment

1. With the application of inert powder into the warehouse, although the whole warehouse can be sprayed evenly, the whole warehouse space is filled with inert powder because the grain is thrown into the warehouse along with the conveyor flow during the feeding process. And because the inert powder itself is very light, as the grain floats in the air after being thrown up, it takes a long time to settle down.

2. Wheat grain is generally fed in from July to September, and the temperature is relatively high. With the application of inert powder to the grain, the grain feeding environment is very poor and the operator's protection requirements are high.

3. The grain replenishment machine is high and operates outside the warehouse. It is difficult to apply inert powder along with the grain during the grain replenishment operation. The grain surface must be leveled after the replenishment is completed, and the grain surface must be sprayed to ensure that the inert powder is evenly applied throughout the warehouse.

6. Inspection and conclusion of pest control effect

In August last year, the grain was sprayed with inert powder. After sampling every month, the pests were checked. After a one-year grain storage cycle, no pests were found and the pest control effect was very good.

Inert powder anti-insect grain storage test, no chemicals are used, and green methods are used to prevent and control insects. Based on its prevention principles, it has opened up new research directions for our green grain storage, and achieved good results. The problem that appears is that the inert powder that enters the silo with the grain will cause the grain's dispersibility to decrease, the porosity to increase, and the bulk density to decrease. The fine particles of inert powder cannot be recycled, causing increased dust pollution when leaving the warehouse. After spraying, the inert powder cannot be recovered completely, and part of the inert powder remaining in the grain will enter the finished grain and bran. After being eaten by humans, animals, and livestock, they enter the human body through the food chain. Since it is uncertain whether inert powder will harm humans and animals, it needs to be carefully monitored in the future to ensure people's health. Inert powder is non-toxic, low cost, and low pollution. It can be combined with air conditioning (low oxygen) and low temperature control grain storage technology to form a green grain storage technology system with Chinese characteristics.