7. Goods must be stacked on double-sided pallets; fresh-keeping pallets cannot be covered with plastic film, which will block the circulation of cold air to the goods; the floor under the goods must not be blocked.
Generally, the floor of refrigerated trucks is made of ventilated aluminum rail floors; but some refrigerated trucks do not have aluminum rails and use flat non-slip floors. Usually, third-party transport companies or corporate transport vehicles for dairy products use flat non-slip floors, the purpose is to be suitable for the transportation of a variety of products, or to facilitate floor cleaning. However, when loading, you must pay attention to using double-sided pallets to load goods to ensure the circulation of cold air on the ground. It is strictly forbidden to stack goods directly on the flat floor.
8. Do not stack goods in front of the evaporator outlet, otherwise it will hinder the cold air flow; obstruction above the goods will cause the cold air flow to short-circuit. Keep a minimum distance of 225 mm between the top of the goods and the roof.
When loading, do not stack the goods too high, and make sure that the loading height is not higher than the flat height of the air outlet. If the air outlet is blocked by goods or too close to the goods, it will not only affect the storage and transportation temperature of the goods, but also affect the normal operation of the refrigeration unit.
Because the air outlet is blocked by goods, the cold air (or hot air) cannot circulate normally in the compartment, thus causing the local temperature of the goods to rise.
On the other hand, some of the defrosting designs of the refrigeration unit use air induction defrosting. When the goods are too close to the air outlet, the coil in the evaporator of the unit will quickly frost (or ice), and the air induction switch will immediately operate, and the unit will quickly enter the defrosting state; when the coil temperature rises to about 9 degrees (design temperature), the defrosting ends immediately. As a result, the unit will have the above-mentioned operation repeated, resulting in the phenomenon that the temperature in the compartment cannot be lowered. The only visual feeling given to everyone is that the unit is always defrosting frequently. In fact, it is caused by the cargo being loaded too high (too much).
9. The interior of the compartment must be kept clean; there should be no wrapping paper and paper scraps on the ground; debris will hinder air flow or be sucked into the evaporator.
When using a refrigerated truck, the interior of the compartment should be kept clean. Due to the action of the evaporator fan, the air will circulate in the car, causing the ground debris or dirt to be sucked into the evaporator fan. Long-term action will cause a large amount of impurities to be sucked into the evaporator coil, thus affecting the refrigeration effect of the refrigeration unit. Because the coil will be surrounded by impurities little by little, the heat exchange rate of the coil will decrease. Therefore, after using the refrigerated truck for a few years, everyone will feel that the refrigeration effect is not as good as at the beginning. In addition to the fault itself, it is because the coil is too dirty. Therefore, ensuring the cleanliness of the floor in the car is the key to ensuring the normal operation of the refrigeration unit.
10. Proper handling; the freezer should be turned off when the door is open; the door should be opened as short as possible; strip curtains should be used as much as possible when loading and unloading goods. Use partitions to separate dry goods (empty baskets) and perishable items.
In order to ensure the temperature of the goods in the car, it is recommended to use strip curtains for urban distribution vehicles to ensure that the cold air in the car will not be lost quickly when unloading quickly (when the refrigeration unit is not turned off).
Goods of different temperatures are strictly prohibited from being stored in the same compartment space. They should be placed separately with partitions. Since the freezer is used to maintain the temperature of the goods, not to cool them down, mixing goods of different temperatures will affect the temperature of the goods and affect the quality of the goods.
Correct operation and use of refrigerated trucks is the key to ensuring the quality of temperature-controlled goods. It is also the key to ensuring that the refrigeration equipment can work properly.