Purchase, installation and use of agricultural cold storage

Update:15 Oct 2021
Summary:

Cold storage for agricultural products is also called f […]

Cold storage for agricultural products is also called fresh-keeping and cold storage. It is mainly to keep fresh. For a long period of time, the original quality and freshness of some agricultural products are kept to the greatest extent, that is, fresh agricultural products are still freshly picked or fresh after being stored for a period of time. It's close to the freshness when it was just picked.

one. The relationship between the fresh-keeping temperature and storage of agricultural products in cold storage

  After the agricultural products are harvested, they are still alive. In the process of storage, to maintain the life of the cold storage insulation board, it must continue to consume its own storage nutrients, thereby gradually losing its nutritional value and fresh quality. In addition, pests and diseases will take the storage and nutrition of agricultural products as delicacies, which will cause agricultural products to spoil and lose their freshness and edible value. Temperature is the most important factor in how to keep the nutrition and fresh quality of the living body of agricultural products after harvest. Generally speaking, the lower the temperature, the lower the nutrient consumption of the product, the worse the damage caused by pests and diseases, and the longer the freshness quality is maintained. At the same time, the smaller the temperature change, the better the preservation effect. The preservation temperature is not unlimitedly low, because when the temperature is so low that the product can't stand it, chilling or freezing damage will occur. Therefore, fresh-keeping storage requires a relatively stable and suitable low temperature condition. The optimum fresh-keeping temperature for most agricultural products is around 0℃.

two. Maintain the optimum temperature for fresh storage of agricultural products

  The temperature is constantly changing with the seasons of the year and the time of the day. Most agricultural products are conventionally cultivated and harvested, and the temperature is relatively high, and the day and night changes are great, which is extremely unsuitable for product preservation and storage. Many simple methods are to find a place where the natural temperature is relatively low and stable to store agricultural products to extend the freshness of the products, such as caves, crypts, shades, etc. These methods cannot control the temperature arbitrarily, and the freshness preservation effect is poor. Relatively short. According to the temperature required for long-term preservation of the product, the final solution is to manually create a relatively stable low temperature condition, that is, through mechanical equipment and electronic instruments, the temperature can be controlled artificially within a certain range of the cold storage insulation board. Various cold storages are just such a facility.

three. Selection and construction of cold storage types and rural origin

   There are many types of cold storage in our country, and the classification lacks a unified standard. A brief introduction according to the commonly used types in the place of origin is as follows:

  (1) According to the storage capacity, it can be classified into large, medium and small. Generally speaking, commercial large and medium-sized libraries have large storage capacities. According to the relatively small characteristics of domestic cold storage and the customary appellation of the masses, the warehouse with a storage capacity of more than 1,000 tons can be called a large warehouse, a warehouse with a storage capacity of less than 1,000 tons and a warehouse of more than 100 tons is called a medium-sized warehouse, and a warehouse with a storage capacity of less than 100 tons is called a medium-sized warehouse. Small library. The production area is most suitable for the construction of small cold storages ranging from 10 tons to 100 tons.

  (2) According to the refrigerant used in the refrigerator, it can be divided into ammonia machine refrigerated ammonia hangar and fluorine machine refrigerated fluorine hangar. Small cold storages built in rural areas can choose fluorine hangars with high degree of automation.

   (3) According to the temperature of the cold storage, there are low temperature storage and high temperature storage. Fruit and vegetable preservation storage is generally high temperature storage, the lowest temperature is -2℃. The fresh-keeping warehouse for aquatic products and meat is a low-temperature warehouse, and the temperature is below -18℃.

   (4) According to the form of cold storage internal cooling distributor, there are pipe cold storage and air cooler cold storage. The fresh-keeping of fruits and vegetables generally uses air coolers, commonly known as cold air storage.

  (5) According to the construction method of the warehouse, it is divided into civil cold storage, assembly cold storage and civil construction composite cold storage. Civil cold storage is generally a sandwich wall insulation structure, which covers a large area and has a long construction period.

  The prefabricated cold storage is a prefabricated warehouse with thermal insulation panels. Its construction period is short, it can be disassembled, but the investment is relatively large. In the civil construction assembly composite cold storage, the load-bearing and peripheral structure of the warehouse are in the form of civil construction, and the thermal insulation structure is in the form of polyurethane spray foaming or polystyrene foam board assembly. Among them, the civil assembly composite cold storage with polystyrene foam board insulation is the most economical and suitable, and it is the preferred form of cold storage in the production area.