How to store grain safely in a grain warehouse?（三）

Last time, we have introduced the knowledge of grain condition inspection and storage temperature and humidity control. Today, HuaZhong Machinery want to share with you the knowledge of insecticide prevention and simple warehouse storage of grain.

1. Prevention and Control of Insects and Molds

1. Insect lines and nets

Arrange and spray food-grade inert powder, deltamethrin or insect-proof insecticides at warehouse doors and windows, exhaust fan openings, vents, etc., and arrange insect-proof lines with a width greater than 10 cm for daily pest control. Deploy insect-proof nets of 80 mesh or more at the doors and windows.

Mobile centrifugal fan

Grain ventilation duct

2. Safe and environmentally friendly prevention and control of stored grain pests

The use of storage chemicals should be reduced as much as possible,

Preference is given to temperature control to prevent pests, and grain surface sealing films to prevent pests.

Under conditions, green and safe physical insect control technologies and biological control technologies such as food-grade inert powder and air conditioning can be adopted.

3. Implement protective agents to prevent insects on stored grains

For grains stored for more than one year, it is advisable to apply protective agents or food-grade inert powder to the bottom layer of the grain pile and the 30 cm high grain on the upper layer of the grain, and apply it at the standard dosage. When spraying machinery is used to apply the protective agent, it should be applied at fixed points and quantitatively when the belt conveyor transports the grain into the warehouse; the carrier of the protective agent should use the same type of grain husk as the stored grain;

Operators using protective agents should be trained,

The applied protective agent should be registered and approved by the national pesticide and other administrative departments.

4. Fumigation to control pests

General insect food with grain temperature above 15℃ should be eliminated within 15 days; severe insect food should be eliminated within 7 days; dangerous insect food should be immediately isolated and thoroughly insecticidal treatment should be carried out within 3 days. Basically insect-free food and general insect food whose food temperature does not exceed 15 ℃ should be strengthened to detect and do a good job of protection, without the need for insecticide treatment.

When fumigating and killing insects, the storage management department of the grain depot shall formulate a fumigation plan based on the species of pests and the level of pest grains, and shall report to the local grain administrative department for the record after being reviewed by the person in charge of the grain depot.And organize the implementation in strict accordance with the requirements of the management and use specifications of grain storage chemicals.

Specific fumigation methods can be natural deliquescence conventional fumigation, circulation fumigation, slow-release fumigation, intermittent application fumigation, phosphine carbon dioxide mixed fumigation, double-low fumigation, tent fumigation, and nitrogen atmosphere and other grain storage methods to kill insects.

Before the implementation of fumigation and air conditioning operations, the person in charge of the warehousing work, the person in charge of the warehousing department, and the safety officer in the grain depot shall check item by item and sign for confirmation in accordance with the contents of the food fumigation and air conditioning operation sheet. After fumigation and dosing or air conditioning and nitrogen filling, the gas concentration should be checked regularly, and if necessary, the amount of medicine or nitrogen should be added to ensure the insecticidal effect. After the fumigation and air conditioning operations are completed, the warehouse clerk and the person in charge of the grain depot storage department shall jointly sign and confirm.

5. Prevention of mildew in stored grain

Control the moisture and impurity content of the grain in the warehouse, adopt mechanical ventilation, low temperature, quasi-low temperature storage and other technologies to prevent and eliminate condensation on the grain pile. When the stored grain shows signs of fever and mold, ozone should be injected into the grain pile or local grain pile in time or phosphine fumigation should be used to kill the mold and suppress the fever. The moldy grain should be cleared out of the warehouse in time.

二. Simple warehouse storage of grain

1. Simple storage of grain

(1) Basic requirements

It should have the basic functions of "Nine Preventions" and "Four Treatments". "Nine-prevention" refers to nine functions of safe grain storage prevention, including fire prevention, moisture prevention, rain and snow prevention, wind prevention, rodent prevention, bird prevention, insect prevention, mildew prevention, and bottom prevention;

The "four treatments" means that four basic measures for safe storage and treatment of grains must be equipped with effective grain condition detection, fumigation and insecticide, ventilation and cooling, and thermal insulation. The person in charge of the grain depot must strictly check, and those who do not meet the basic requirements shall not store grain.

Intelligent grain truck probe in the grain depot

(2) Grain enters the warehouse

Before entering the grain, do a good job of insecticide and disinfection of simple stockpile foundation, packaging and thatch cover materials, etc., according to the requirements of GB/T 29890.

When feeding grain, the grain should be fed evenly from the center point of the simple grain storage to prevent partial load, reduce impurities and automatically classify and prevent dust from flying.

The temperature measurement cables of the simple grain store are arranged in a ring, and the distance between adjacent cables in the horizontal direction is not more than 5 m, the distance between adjacent cables in the vertical direction is not more than 3 m, and the distance between the grain surface, the bottom and the wall of the grain is 0.3 to 0.5 m.

(3) Grain condition inspection

When the grain temperature of the simple grain store is below 15°C, perform a survey at least once within 5 days; when the grain temperature is 15°C～25°C, perform a survey at least once within 3 days; when the grain temperature exceeds 25°C, perform a survey once a day. Randomly check grain temperature, moisture, pests, mildew and other conditions every month; check grain conditions in time for inclement weather. Record the inspection results in the grain condition (grain temperature) report.

By sampling or combining with the arrangement of temperature measurement points, the grain moisture can be sampled by layers or on-line detection. Appropriately increase the detection points and frequency of surface and upper grain moisture; surface grain moisture should be tested once a week; middle and upper grain moisture should be tested at least once a month; when the season changes, the number of inspections of grain pile surface moisture should be increased.

For grains stored for more than one year, the frequency of grain condition inspections should be increased.

(4) Grain storage measures

After entering the grain, the surface of the grain pile should be treated with pest control and mildew prevention. Insect lines should be sprayed around and at the bottom of the simple grain storage, and insecticide or food-grade mildew-proof agent should be sprayed according to the storage period of the grain and the surrounding environmental conditions. The frequency of spraying should be increased during the seasons and the high incidence of insect pests.

For simple storage, an above-ground cage ventilation duct can be used. Under the condition of a sealed grain storage, a combination of vertical pressure in and suction is used for mechanical ventilation, and a unit ventilation volume of 6-15 m3/h·t should be selected.

The main pests are more than 2 heads/kg, and the grain storage should be sealed and then fumigated and and do the pest killing.

When the grain pile has serious moisture stratification, local condensation, high temperature and heat, etc., timely adopt ventilation and other treatment measures. When the ventilation fails to meet the requirements, the surface layer of the grain pile must be overturned, demolition, and upside-down disposal. When the upper layer of the simple storage grain is condensed, uncover the tarpaulin at the right time,silp the grain surface, and perform natural moisture dissipation treatment.

(5) Grain delivery operations

Open the symmetrical grain outlet of the grain store to deliver grain at the same time, so that the flow rate is consistent, and the grain is delivered slowly and evenly to prevent the unbalanced load and dumping of the body. Or use an auger to draw out grain from the center of the bottom of the stock to form a circular grain pile in the center of the stock to prevent the tilt of the stock

2. Canopy storage of grain

The shed grain storage mainly adopts the storage form of enclosed bulk storage and packed grain stacking.

(1) Basic requirements

It should have the basic functions of "Nine Preventions" and "Four Treatments". The packaging sacks should be disinfected to avoid cross-infection, causing hidden dangers such as grain pests. It is not allowed to use plastic woven bags to store grain as a retaining wall for the storage of bulk grains.

(2) Grain storage operation

When grain enters the grain store, a grain cleaner should be used to remove impurities; multiple grain feed points should be used at the same time to reduce impurities and automatically classify and prevent dust from flying. The mechanized warehousing treatment should minimize grain breakage. The ventilation system should be scientifically designed, and the ventilation ducts should be reasonably arranged to reduce the dead angle of ventilation, prevent running and leakage, and ensure the ventilation effect. 

The thickness of the retaining wall surrounding the package and bulk storage should ensure the safety of the load after the grain is loaded. The arrangement of the grain retaining wall should be carried out simultaneously with the grain warehousing. When building a grain retaining wall, conveyors should not be used to transport grain bales. All sacks used should be intact, free from damage, pollution, and pests. 

New sacks should be used in the lower part of the grain retaining wall. Reinforce and thicken the long side of the grain retaining wall every 3 m, and clean up the grain and debris on the sack in time for each layer, and then build another layer. The height of the retaining wall is not more than 5m, and the total storage of a single (per district) canopy is not more than 20000 t.

(3) Grain storage measures

The layout requirements of the grain condition detection system and sensors are the same as those of the room-type warehouse.

The surface layer of the grain pile should be treated with pests and mildew. The methods and requirements are the same as those of the simple grain storage. The main pests are more than 2 heads/kg, and the grain stacks should be sealed and fumigated to kill the insects.

(4) Grain out of warehouse operations

The rat nets and boards should be removed first, and then the cover should be removed.The sequence of removing the grain retaining wall is to move the grain bales layer by layer from top to bottom and from outside to in. The height and width of the removed grain retaining wall should be consistent with the self-flow angle of the grain pile.

The bottom material under the grain retaining wall should be removed while discharging the grain.If the grain is delivered in batches, the grain condition testing equipment and ventilation system should be guaranteed to work normally.

During the grain out of warehouse period, a dedicated person should check in real time and find whether the grain stacks and facilities are skewed, and should immediately stop the grain delivery and promptly dispose of it. After the grain is delivered, the venue, related equipment and equipment should be cleaned and tidied up in time.

3. Steel structure bulk room type simple grain storage warehouse

The grain retaining structure must be able to withstand the side pressure of the grain pile under dynamic and static loads, and the calculation basis of the steel structure bulk house-type simple grain warehouse design department should be provided.

It must be equipped with effective grain condition detection, ventilation and fumigation process equipment. The requirements for grain condition detection are the same as those of a regular room-style warehouse. Ventilation and fumigation technical measures shall be taken in time after manual review and confirmation of abnormal grain conditions to ensure safe grain storage. During the alternate seasons, strengthen the inspection of dew condensation and mildew on the surface, periphery, corners, and under the aisle slabs of grain piles.

In the high temperature season, the grain surface should be turned over to dissipate the heat accumulated on the top of the grain pile. When airtight and covered, a layer of moisture-absorbing and heat-insulating material can be laid on the grain surface first, and then covered with a thatch cloth to prevent condensation.

The above is the relevant knowledge of insect and mildew control and simple warehouse storage that we shared with you today. Next, the HuaZhong Machinery will continue to share with you: What should we do if there is an abnormal food situation? What issues should we pay attention to in grain out of grain warehouse operations? Let us look forward to it together!

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