Packaging and stacking airtight storage method of agricultural products under mechanical controlled atmosphere mode

Abstract

The invention belongs to the technical field of mechanical controlled atmosphere storage and maintenance of agricultural products. The agricultural product packaging and stacking airtight storage method under the mechanical atmosphere mode is characterized in that: the agricultural product is packed into a packaging bag made of polyethylene plastic film with a non-polar molecular structure and stacked and stored in the warehouse. The nylon composite film made of polar nylon material and non-polar polyethylene material is made into a plastic airtight tent according to the size of the stack of agricultural products and sealed and covered on the stack of agricultural products; while inside the stack The agricultural product packaging bag can allow non-polar nitrogen, oxygen, and carbon dioxide to enter and exit freely, but can block polar water molecules from escaping or entering the agricultural product packaging bag; The synchronous back-injection of gas and nitrogen and the new process technology and equipment configuration mode reserved in the confined space ensure the synergistic effect of carbon dioxide on the control of nitrogen atmosphere to prevent insects and mildew.

Description

technical field [0001] The invention belongs to the technical field of packaging and stacking airtight storage and maintenance of agricultural products, and in particular relates to a method for packaging and stacking airtight storage of wheat and tobacco leaves in a mechanically controlled atmosphere mode. Background technique [0002] The safe storage and management of plant products obtained from agricultural production is an important issue. Some agricultural products, especially wheat and harvested tobacco leaves have their unique storage and maintenance characteristics. It can achieve better eating quality, during which there will be vigorous respiration, which will absorb oxygen and release a large amount of carbon dioxide gas; after the tobacco leaves are planted, there will also be strong respiration during the initial roasting and after threshing and re-baking. It absorbs oxygen and releases a large amount of carbon dioxide gas. In this process, the natural aging o...

AI Technical Summary

Problems solved by technology

[0006] ①.For agricultural products packed in cartons, due to the thick carton body, it is very difficult to monitor and sample the temperature and humidity of agricultural products in the box during the storage of tobacco leaves. The damage caused by the barrier of the carton is also more serious;

[0007] ②. Tobacco leaves packaged in cartons, due to the strict airtightness and good airtightness of the cartons, it is difficult to manually intervene in the air composition and humidity in the cartons during the mechanical control process to make the moisture, nitrogen, oxygen, and carbon dioxide gas molecules enter the cartons smoothly. , which increases the difficulty of mechanical regulation and the energy consumption of equipment;

[0008] ③. Traditional agricultural product packaging and stacking airtight tents use a variety of materials, including polar materials such as polyvinyl chloride, nylon, and polyester materials, as well as non-polar materials such as polyethylene, polypropylene, and polypropylene; the existing Neither the technology nor the public information paid attention to the specific performance and directional selection of the materials selected for the agricultural product packaging bag and the agricultural product stacking airtight tent, nor did they design a scientific combination method for different materials between the two, resulting in During the implementation of the low-emission mechanical control technology, the penetration of nitrogen, carbon dioxide and other gases injected into the airtight stack is difficult to effectively exert (difficult to enter the inner packaging bag), and plastic airtight tents with mismatched performance can easily lead to piles of agricultural products. The gas concentration in the inner space of the stack is difficult to maintain, and the water loss of agricultural products in the packaging bag is also serious;

[0012] ⑤. The traditional method consumes a huge amount of cartons and plastic lined bags every year, and the workload of waste treatment is also quite large, which has become an important cost expenditure of the domestic tobacco industry

[0015] ①. Chinese application number 201110194666.1 patent uses the mixed gas of nitrogen and carbon dioxide to make the concentration of various gas components in the sealed agricultural product stack gradually reach one of the following three conditions to improve the insect control efficiency: the volume concentration of nitrogen 85-97%, the volume concentration of carbon dioxide is 2-14%; the volume concentration of nitrogen is 70-85%, the volume concentration of carbon dioxide is 14-29%; the volume concentration of nitrogen is 40-70%, the volume concentration of carbon dioxide is 29-59%; the concentration combination of the above three gas mixtures is only a description of the goal of aeration, and there is no available process and equipment conditions to meet the above goals. If a nitrogen generator is used to perform the above nitrogen volume concentration To achieve and maintain the target, the nitrogen generator will simultaneously replace the carbon dioxide gas in the stack of sealed agricultural products during the operation of filling nitrogen. Like the membrane separation nitrogen production equipment, the carbon dioxide gas must be separated and excluded from the sealed stack, so it is impossible to effectively implement the demands provided by the above-mentioned patented technology by using the nitrogen generating device in actual work;

The above description also only stays at the description of the target level of filling nitrogen and carbon dioxide, lacks the actual operation process method, and has no technical path for realization; moreover, the technical model of filling the airtight tent with a volume concentration of 97% carbon dioxide is not It meets the policy requirements of low-carbon environmental protection and cannot be promoted and applied;

[0017] ③. Chinese application numbers 201110204112.5 and 201110204134.1 provide a rapid insecticide method for agricultural products, relying on the nitrogen-generating equipment's gas charging port, gas pumping port and the air circulation circuit formed by the airtight insecticidal environment. Repeated cycle deoxygenation makes the nitrogen concentration higher and higher When the oxygen concentration detector detects that the oxygen concentration in the sealed agricultural product stack is below 5%, then fill in carbon dioxide gas so that the carbon dioxide concentration is 3-50%, and the oxygen concentration in the sealed agricultural product stack is below 2%, and maintain the gas concentration 3-10 days to increase the rate of nitrogen-filled insecticide; although this method is beneficial to improve the rate of nitrogen-filled insect control, in the actual application process, if the circulation in the confined space is removed first, the oxygen in the confined space If the concentration is lowered to below 5%, then the exhaust fan is used to extract the gas in the confined space, and at the same time, carbon dioxide gas is charged individually. There are the following problems: First, the nitrogen and carbon dioxide extracted by the exhaust fan cannot be circulated into the confined space, which not only causes a lot of waste, Increase the cost of insecticide, and the high concentration of nitrogen and carbon dioxide pumped out has the potential risk of suffocation, and also poses a safety hazard to the surrounding environment

Second, if after injecting carbon dioxide, use a pressure swing adsorption nitrogen generator or a membrane separation nitrogen generator to circulate nitrogen into the sealed agricultural product stack to maintain the nitrogen concentration, this process will also inject nitrogen into the closed stack. If the nitrogen generator is not used to circulate nitrogen into the sealed agricultural product stack to maintain the nitrogen concentration, the nitrogen concentration inside the sealed stack will not be able to stably reach the effective concentration for pest control;

[0018] The shortcomings and defects of the above-mentioned disclosed technical methods are that there is no process or equipment system for how to store carbon dioxide and nitrogen together in a closed space; although the nitrogen generator used in the previous nitrogen filling technology can guarantee extremely high purity Nitrogen enters the confined space, but the carbon dioxide and oxygen produced by respiration during the storage of agricultural products in the closed tent are removed outside the closed space, even in the cycle nitrogen production mode, the carbon dioxide in the closed space is extracted and released. Excluded from the confined space, so that the synergistic and synergistic effect of the carbon dioxide in the stacking of agricultural products on the insect control of the nitrogen atmosphere will not be brought into play

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