Cold storage fresh-keeping is an indispensable refrigeration equipment in modern society. It has a wide variety of varieties. Everyone has heard of it, fresh-keeping warehouse, constant temperature storage, cold storage, freezer, quick-freezing cold storage, quick-freezing flatbed, and air-conditioning fresh-keeping cold storage. The air-conditioned cold storage is one of them. Today, the speed wind cooling will come to you to introduce.
Some customers do not understand what is a controlled atmosphere cold storage, and the air conditioning cold storage is also called a modified atmosphere library or a modified atmosphere storage. Composition: The air-conditioning warehouse is generally composed of an airtight storage system, a gas-conditioning system, a refrigeration system, a humidification system, a pressure balance system, and an automatic detection and control system for temperature, humidity, O2, CO2, and gas.
The atmosphere-controlled fresh-keeping cold storage is to control the proportion of gas to achieve the purpose of storage and preservation. The modified atmosphere preservation technology is a technology for prolonging the storage life and shelf life of food by adjusting the ambient gas. The main principle is: in the sealed cold storage, various adjustment methods are used to obtain a regulating gas different from the normal atmospheric components, and the inhibition causes the food to be defeated. Physiological and biochemical processes and microbial activities.
The air-conditioning cold storage is mainly used for storing fruit and vegetable products. It is the world's most advanced fruit and vegetable cold storage equipment, which can fully meet the temperature, humidity, oxygen and carbon dioxide concentration in the cold storage, ensuring that the fruits and vegetables are fully refrigerated. The longest storage, and can retain the nutrients of fruits and vegetables to the greatest extent, improve the storage quality of fruit and vegetable products, which is not comparable to other types of cold storage.
The use of air-conditioned cold storage to store fruits and vegetables can be extended to 1.5 times to 3 times longer than other cold storages, providing users with longer sales time and greater economic benefits. After the fruit and vegetable storage is completed, the nutrients and warehousing contained in the storage are almost the same, which will not affect the taste and improve the competitiveness of the fruit and vegetable products.
The low-temperature storage of the air-conditioned cold storage can effectively inhibit the effects of pests and diseases of fruits and vegetables, and there is no frost damage, which fundamentally reduces the weight loss of fruits and vegetables. For fruits and vegetables that are more difficult to store, the best storage effect can be achieved, which can effectively increase the income of farmers.
Although the initial investment in the air-conditioning cold storage is higher than other cold storage costs, the economic benefits of the air-conditioning cold storage are considerable compared with the positive benefits created by the air-conditioning cold storage and the service life.
Traditional methods for storage and preservation of fruits and vegetables include simple storage, storage in a ventilated warehouse, radiant preservation, chemical preservation, and cold storage. The simple storage and ventilation storage equipment is simple and the investment is small, but the storage effect is poor, the storage period is short, and the rot loss is serious. Radiation and chemical preservation have certain applicability on some fruits, but there are radiation and chemical residue pollution, not all fruits and vegetables can be applied.
Atmospheric storage can maximize the storage environment of fruits and vegetables by changing the gas composition and relative humidity of the storage environment under suitable low temperature conditions. The effect is as follows: hypoxia (usually O2 content) %-5%), appropriate CO2 concentration can effectively inhibit respiration, reduce the loss of nutrients in fruits and vegetables, inhibit the growth and reproduction of pathogenic bacteria, control the occurrence of certain physiological diseases; remove ethylene in the storage environment gas to inhibit it The ripening effect of fruits and vegetables delays the process of post-ripening and aging; increases the relative humidity in the ambient gas to reduce the transpiration of fruits and vegetables, thereby achieving the purpose of long-term storage and preservation of fruits and vegetables. Therefore, the fruits and vegetables that have been stored under controlled atmosphere have the following characteristics: (1) maintaining the original shape, color and aroma of the fruits and vegetables; (2) the fruit hardness is higher than that of ordinary refrigeration; (3) the storage time is prolonged; (4) the fruit Low rot rate, low natural loss (water loss rate); (5) extended shelf life. Due to the long-term effects of low 02 and high CO 2 on fruits and vegetables, there is still a long period of “hysteresis” or dormancy during the period of deregulation; (6) suitable for long-
distance transportation and export. The quality of fruits and vegetables has improved significantly, creating conditions for export and distribution; (7) Many fruits and vegetables can reach the annual supply of annual output, creating good social and economic benefits.
The atmosphere storage library not only requires good heat insulation, but also reduces the influence of external heat on the temperature inside the storage. More importantly, it requires good air tightness, reducing or eliminating the pressure of the outside air on the gas components in the reservoir. The gas composition in the library is adjusted quickly and the fluctuation range is small, thereby improving the storage quality and reducing the storage cost. The atmosphere storage library is mainly composed of an inner liner and an insulation layer. The atmosphere-controlled fresh-keeping warehouse can be divided into three types according to the building: assembled, brick-mixed, and jacketed. The assembled air-conditioning warehouse envelope structure is assembled by color-plated polyurethane sandwich panels, which has the functions of heat insulation, moisture resistance and airtightness. This type of library is fast and beautiful, but the cost is slightly higher. It is the most commonly used type of new air conditioning library at home and abroad. The air-conditioning warehouse uses a special air-conditioning valve, which should have good thermal insulation and air tightness. In addition, in the long-term storage process after the air-conditioning warehouse is closed, it is generally not allowed to open the air-conditioning door casually, so as to avoid gas exchange inside and outside the warehouse, causing fluctuations in the gas composition in the warehouse. In order to facilitate the understanding of the storage of fruits and vegetables in the warehouse, an observation window should be set. . After the air conditioning library is built, air tightness testing is required. The air tightness should reach 300Pa, and the half-blow time should be no less than 20-30min.
Characteristics of modified atmosphere storage: wide application range: suitable for fruit storage of fruits and flowers in the north and south of China. The storage and storage period is long and the economic benefits are high. If the grapes are fresh for 7 months, apples are 6 months, and after 7 months of garlic, the quality is fresh and fresh, and the total loss is less than 5%. The average price of grapes is only 1.5 yuan / kg, and the price can be 6 yuan / kg before and after the Spring Festival. A one-time investment in the construction of a cold storage, the service life of up to 30 years, the economic benefits are very significant. The investment in the year was effective in the same year. The operation technology is simple and the maintenance is convenient. The refrigeration equipment microcomputer controls the temperature, automatically starts and stops, no need for special personnel supervision, and the supporting technology is economical and practical.
It can not only regulate the temperature and humidity in the library, but also control the content of oxygen, carbon dioxide and other gases in the library, so that the fruits and vegetables in the library are in a dormant state, and the original quality is maintained after the storage.
Carbon Molecular Sieve Adsorption Nitrogen Generator Carbon Molecular Sieve Nitrogen is produced by the principle of pressure swing adsorption. Due to the different kinetic diameters of oxygen molecules and nitrogen molecules, the diffusion rate of oxygen molecules is hundreds of times faster than that of nitrogen molecules. The adsorption amount is proportional to the pressure, and the characteristics of the difference in the adsorption amount of oxygen and nitrogen in a short time are very high. The program controller performs rapid switching between the two towers according to a specific time program, combined with pressurized oxygen adsorption and reduced pressure oxygen. The process of desorption separates oxygen from the air. The carbon molecular sieve nitrogen generator has the characteristics of high purity of nitrogen (up to 99.9%), simple equipment and low price. However, there are many valves in the equipment and frequent switching. Each valve needs to be switched between 200,000 and 400,000 times per year. Big. Therefore, it is required to ensure the quality of the valve, otherwise it will affect the reliability of the equipment.
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