1. Modified Atmosphere Storage Container

Airtightness is a key characteristic that distinguishes controlled atmosphere storage facilities from refrigerated warehouses. Controlled atmosphere storage requires the protective structure to not only provide thermal insulation and moisture prevention, reducing heat exchange with the outside, but also to ensure strict sealing around the walls, doors, and all pipeline connections to minimize gas exchange between the interior and exterior. Only then can the gas composition within the storage be artificially adjusted, reducing or avoiding interference from external gases. Due to the stringent requirements for airtightness in the protective structure of controlled atmosphere storage, as the temperature and pressure inside the storage change during the cooling and gas adjustment process, a pressure difference may occur between the two sides of the protective structure, potentially damaging the airtight layer or even causing the protective structure to crack or collapse. To balance and reduce the pressure difference between the interior and exterior of the storage, controlled atmosphere storage facilities need to be equipped with safety valves and gas adjustment bags, and it is recommended to use gas adjustment equipment that employs positive pressure nitrogen infusion and oxygen reduction.

Refrigeration Equipment

Modern controlled atmosphere storage design aims to keep the temperature fluctuation within ±0.5℃. To achieve this, in addition to requiring the protective structure to have a high thermal resistance to minimize external influences, the evaporator design within the storage should employ a large-area, low-temperature difference air cooler scheme. The entire refrigeration system design of the controlled atmosphere storage can adopt either centralized cooling with large units or individual storage room cooling with small units, depending on different circumstances; the latter offers greater flexibility. To ensure the refrigeration unit operates economically during the controlled atmosphere process, the insulation layer of the storage's protective structure should be thicker than that of general high-temperature storage.

3. Climate Control Equipment

Nitrogen Generation and Oxygen Reduction Equipment

The aeration storage facility typically uses a positive pressure inflation displacement method to reduce oxygen levels. This involves obtaining nitrogen with a high concentration (≥98% nitrogen content) through a nitrogen generation and oxygen reduction system, which is then run through the oxygen reduction equipment system and infused into the storage facility via pipelines. Simultaneously, the oxygen-rich air within the storage facility is exhausted through another pipeline. This process of inflation and exhaust is repeated, effectively reducing the oxygen content within the storage facility to approximately 3%-5%. Subsequently, through the respiration of the fruit itself, the oxygen level continues to decrease, and the carbon dioxide concentration is increased, thereby achieving the goal of adjusting the gas composition within the storage facility.

(2) Carbon Dioxide Removal Machine

During the controlled atmosphere storage of fruits and vegetables, the release of carbon dioxide due to their respiration gradually increases the concentration of CO2 within the storage. When the CO2 concentration reaches a certain level, it can cause CO2 damage and trigger a series of adverse symptoms, leading to spoilage and deterioration. At this point, it is necessary to use a CO2 removal machine to eliminate the excess CO2 from the storage to achieve the desired controlled atmosphere parameters.

(3) Ethylene Removal Unit

Ethylene is a plant hormone that promotes the respiration and accelerates the aging of fruits and vegetables, sometimes referred to as the "ripening hormone." It is a byproduct of the fruit's own metabolism and is also present in certain amounts in the smoke emitted from chimneys, vehicle exhaust, and exhaust gases from some factories. Fruits highly sensitive to ethylene require the installation of ethylene removal devices to reduce the ethylene concentration in storage conditions to below the threshold level.

(4) Automatic Control Equipment

The controlled atmosphere (CA) storage facilities require precise measurement and control of the gas composition throughout the storage period. To enhance the level of automation in the operation and management of CA storage, domestic and international manufacturers of CA equipment have developed corresponding automated control systems, largely automating the aforementioned tasks. A single control system can manage around 20 CA chambers, with each chamber capable of setting its own CA parameters according to the type of fruit and performing automatic巡回 inspections.

4. Humidification Systems and Disinfection Equipment

Due to the long storage period of fruit products in a controlled atmosphere warehouse, the nitrogen infused is also very dry, leading to significant moisture evaporation. To reduce the vapor pressure difference between the storage environment and the fruit products, and to maintain a higher relative humidity in the warehouse while minimizing water loss in fruits and vegetables, it is common to install a sealed ultrasonic humidifier in the warehouse. Ozone sterilization is a safe and environmentally friendly technology that utilizes the air inside the warehouse to produce ozone (ionized oxygen) in a controlled manner, thereby reducing the proliferation of various pathogens and microorganisms. It can mitigate a series of issues caused by long-term cold storage, such as premature aging, spoilage, pathogen growth, and water loss. After a period of storage, it helps maintain the quality and freshness of the fruits, with low maintenance costs and equipment that does not require replacement filters, membranes, or tablets.