As an essential handling equipment in all links, the cold storage forklift has attracted more and more attention in the industry, especially the battery forklift has become the first choice for the food industry and cold chain logistics companies.
Characteristics of cold storage environment
1. There are four kinds of cold storage according to the temperature range
(1) The high-temperature storehouse has an L level of + 5 to - 5 degrees Celsius. It is mainly used to store vegetables, eggs, medicinal materials and wood for preservation and drying.
(2) The medium temperature storehouse is grade D - 10 to - 18 degrees Celsius. It is mainly used to store meat, aquatic 名媛直播 and other 名媛直播 suitable for this temperature.
(3) The low-temperature storage is j-grade - 23 to - 28 ℃, which is mainly used for ice cream, ice cream and low-temperature food.
(4) The ultra-low temperature warehouse is lower than - 30 ℃. It is used for quick-frozen food, industrial, medical and other special purposes. High temperature storage does not need special cold storage forklift, and other cold storage need to use cold storage forklift. 2. Working environment with extreme temperature and humidity changes
Especially in the South and coastal areas, due to the high outdoor environmental humidity, the humidity in the charging area and loading and unloading area outside the cold storage is much higher than that in the cold storage. The forklift operates in the cold storage for more than half an hour, and its surface temperature is close to the ambient temperature in the cold storage. When the forklift leaves the cold storage to enter the charging area or loading and unloading area, condensation and condensate appear on its surface in a short time.
Hardware requirements of cold storage forklift
(1) Metal parts need special anti rust treatment;
(2) Low temperature materials shall be selected for rubber parts to ensure their working state at low temperature;
(3) The wheels are made of polyurethane with low hardness, and the surface is slotted to prevent slipping and have sufficient bearing capacity. The hardness is generally 72sh;
(4) Select oil 名媛直播 with low temperature characteristics, such as Mobil Mobil HVI 26 or shell aero shell 41 for hydraulic oil; Gear oil is refrigerated, model: 75w-90 GL-5 - 60 ℉ ~ 90 ℉; Low temperature lubricating oil shall be used for portal frame and bearing lubricating oil, model: shell Steiner HDS or Mobil 532, etc;
(5) The hydraulic cylinder is equipped with vent holes, and the surface of piston rod is plated with chromium alloy and thickened;
(6) Sealing or heating devices for all electrical systems;
(7) Fill all plugs with special grease;
(8) The controller must reach IP54 protection grade, and some parts must reach IP65 protection. If necessary, it shall be sealed and isolated;
(9) Liquid crystal displays need sealing and heating devices.
Application characteristics of forklift in cold storage
1. Frequent access to cold storage and handling of goods
This operation mode is suitable for the operation of balance weight battery forklift and battery hand-held turning. It is a common way of plane transportation. As the first choice of plane transportation, it has low waterproof requirements for forklift, and the service life of forklift hardware (such as oil pipe, oil seal and other vulnerable parts) is relatively long.
2. Long time handling of high shelf stacking and unloading
Due to the different working characteristics, the task of the narrow roadway stacker is to stack the goods transported into the cold storage on the plane to the high shelf, or take the goods from the high shelf to the ground. Therefore, in use, the continuous operation time in the cold storage is relatively long.
3. Use of vehicles of different grades in different cold storage environments
(1) The refrigerated truck at - 18 ℃ shall not work for more than 1 hour in the cold storage at a temperature higher than - 18 ℃.
(2) Refrigerated trucks at - 30 ℃ can be used in the cold storage at - 18 ℃ without time limit. The working time in the cold storage at - 18 ℃ to - 30 ℃ shall not exceed 15 minutes / hour.
(3) Refrigerated vehicles with temperature of - 40 ℃ can be used in the cold storage with temperature of - 18 ℃ without time limit. Working in the cold storage with temperature of - 18 ℃ to - 30 ℃ shall not be operated for 3 hours, but must operate outside the cold storage for half an hour or rest for the same time. The working time in the cold storage shall not exceed - 40 ℃ / 15 hours.
Influence of battery discharge characteristics on the use of cold storage vehicles
Due to the chemical characteristics of the battery, the freezing point of the electrolyte is closely related to the specific gravity. Under low temperature, the battery cannot discharge normal electricity.
1. Freezing point of electrolyte
(1) The freezing point of sulfuric acid with specific gravity of 1.13 is about - 12 ℃
(2) The freezing point of sulfuric acid with specific gravity of 1.29 is about - 60 ℃
Below zero, the battery can discharge less than 60% of the total capacity
2. Battery selection and precautions during use
(1) Select high-grade brand batteries to ensure the use of forklifts and battery replacement time;
(2) Try to keep the battery in a full state and ensure that the specific gravity of battery electrolyte is in a high specific gravity state;
(3) The forklift and battery should be preheated before entering the cold storage;
(4) Keep the battery surface dry and the battery liquid level high.
Establish buffer zone to prevent high temperature operation of forklift
Through long-term application research, we have a method to prevent the generation of a large amount of condensate: if a buffer zone is built between the cold storage and the charging area and the loading and unloading area, after the forklift is used for a specified period of time, the forklift leaves the cold storage, rests in the buffer zone and changes the battery, so as to ensure that the temperature of the buffer zone is about 0 ℃ and the humidity is controlled below 40%, the generation of condensate can be effectively controlled. The humidity of the buffer zone can be controlled with the help of the dehumidifier, and the temperature can be controlled by isolating the loading and unloading area to ensure low humidity.
Precautions for the use of cold storage vehicles
(1) All cold storage vehicles shall not be shut down and parked in the cold storage, otherwise the hydraulic system and electrical system may be damaged.
(2) Before entering the cold storage, all cold storage vehicles must do hydraulic and walking actions, and enter the cold storage after the temperature of each component rises.
(3) According to different cold storage vehicle grades, operate in the cold storage according to the standard sustainable working hours.
(4) After the vehicle leaves the warehouse, if there is condensate on the surface, it must be dried or wait for the condensate to dry completely before entering the cold storage again.
(5) Use special oil 名媛直播 for cold storage and maintain and replace them regularly.
(6) Shorten the maintenance cycle of lubrication points and prevent early wear of lubrication points.
(7) The battery cannot be left vacant for a long time after discharge. Charge it in time and maintain a high proportion of electrolyte to prevent freezing of battery electrolyte.
(8) Different models cooperate to improve the efficiency of various models in the cold storage.
(9) When the vehicle fails in the cold storage, it must be removed from the cold storage as soon as possible and repaired in the buffer area or maintenance area. Cold storage forklift is a kind of special handling machinery. Its use and maintenance methods are directly related to the service life of forklift. The combination of professional recommended models and various models and professional maintenance and repair can ensure the effective utilization rate, intact rate and service life of cold storage forklift.
