Cold storage forklifts are an essential handling equipment in each link and more and more attention in the industry, especially ELECTRIC FORKLIFT, including ELECTRIC PALLET TRUCK, ELECTRIC PALLET STACKER, ELECTRIC REACH TRUCK, etc., and have become the first choice for the food industry and cold chain logistics companies. It is necessary to understand the requirements of forklifts working in cold storage environment.

一、the characteristics of cold storage environment

1、according to the temperature range is divided into 4 kinds of cold storage

(1) High temperature warehouse L +5 to -5 degrees Celsius, mainly used to store vegetables, eggs, medicinal materials, wood preservation and drying;

(2) Medium temperature storage D class -10 to -18 degrees Celsius, mainly used to store meat, aquatic products and other products suitable for this temperature; (3) Low-temperature storage J-23 to -28 degrees Celsius, mainly used for ice cream, ice cream and low-temperature food;

(4) Ultra-low temperature storage below -30 degrees Celsius, frozen food and industrial, medical and other special purposes. High temperature storage does not require a special cold storage forklift, other cold storage need to use cold storage forklift.

2、extreme temperature and humidity changes in the working environment

Especially in the south and coastal areas, the humidity of the outdoor environment causes the humidity of the charging area and the loading 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, the surface temperature is close to the ambient temperature in the cold storage, the forklift opens the cold storage into the charging area or the loading area, and the surface of the condensation and condensate appear in a short time.

二、the hardware requirements of cold storage forklift

1、metal parts need special anti-rust treatment;

2、rubber parts need to choose low-temperature materials to ensure its working state at low temperature;

3、the wheel is made of low hardness polyurethane material, the surface is slotted to prevent slippage and sufficient bearing capacity, the hardness is generally 72SH;

4、select low-temperature characteristics of the oil;

5、the hydraulic cylinder is equipped with air holes, and the surface of the piston rod is plated with chromium alloy and thickened;

6、all electrical systems with sealing or heating devices;

7、All plugs are filled with special grease;

8、the controller must reach IP54 protection level, some parts need to reach IP65 protection, if necessary, sealant isolation treatment;

9、liquid crystal display requires sealing and heating device.

三、the application characteristics of forklift trucks in cold storage

1、Frequent handling of goods in and out of cold storage

This mode of operation is suitable for counterweight battery forklift truck and battery hand pallet truck operation, is a common way of plane handling, it is the first choice for plane handling, the waterproof requirements of forklift trucks are lower, forklift hardware (such as: oil pipes, oil seals and other wearing parts) life is relatively long.

2、long time to deal with high shelf stacking and unloading

Due to the different working characteristics, the task of the narrow roadway stacker is to stack the goods carried into the cold storage on the high shelf, or take the goods from the high shelf to the ground, so it is in use, and the continuous operation time in the cold storage is relatively long.

3、the use of different levels of vehicles in different cold storage environments

(1) The refrigerated truck at -18 ° C shall not work for more than 1 hour in the cold storage at a temperature higher than -18 ° C;

(2) The refrigerated truck of -30℃ can be used in the cold storage of -18℃, there is no time limit, and the working time in the cold storage of -18℃ to -30℃ shall not exceed 15 minutes/hour;

(3) The refrigerated truck of -40 ° C can be used in the cold storage of -18 ° C, there is no time limit, and the work in the cold storage of -18 ° C to -30 ° C shall not operate for 3 hours, and must be operated outside the cold storage for half an hour or rest for the same time. The working time shall not exceed 15 minutes/hour in the -40℃ cold storage.

四、the impact of the discharge characteristics of the battery on the use of the cold storage forklift

Due to the chemical characteristics of the battery, the freezing point of the electrolyte has a great relationship with the specific gravity, and the battery can not release normal electricity at low temperature.

1、Freezing point of electrolyte

(1) The freezing point of sulfuric acid with a specific gravity of 1.13 is about -12℃;

(2) The freezing point of sulfuric acid with a specific gravity of 1.29 is about -60℃;

(3) Below zero, the battery can release less than 60% of the total capacity.

2、battery selection and use of precautions

(1) Select high-grade brand batteries to ensure the use of forklift trucks and battery change time;

(2) Try to keep the battery in a full state to ensure that the specific gravity of the 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 height.

五、establish a buffer zone to prevent forklift high temperature operation

Through long-term application research, we have a method to prevent the generation of large amounts 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 is opened out of the cold storage, rest and replace the battery in the buffer zone, and ensure that the temperature of the buffer zone is about 0 degrees 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 a dehumidifier, and the temperature can be controlled by isolating the loading and unloading area to ensure low humidity.

六、 the use of cold storage forklift precautions

1、all cold storage vehicles can not be turned off and parked in the cold storage, otherwise it may lead to damage to the hydraulic system and electrical system;

2、all cold storage vehicles must do hydraulic and walking actions before entering the cold storage until the temperature of each component rises and enters the cold storage;

3、according to different grades of cold storage vehicles, in accordance with the standard sustainable working hours in the cold storage operation;

4、if there is condensate on the surface of the vehicle after leaving the warehouse, it must be dried or wait for the condensate to dry out before entering the cold storage again.

5、the use of cold storage special oil, regular maintenance and replacement;

6、Shorten the maintenance period of lubrication points to prevent early wear of lubricating points;

7、the battery can not be vacant for a long time after discharge, timely charging and maintain a high proportion of electrolyte to prevent the battery electrolyte from freezing;

8、different models cooperate with the operation to improve the effectiveness 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 zone or maintenance area.

Cold storage forklift truck is a special handling machinery, its use and maintenance methods are directly related to the service life of the forklift truck, professional recommended models and various models of use, professional maintenance and repair can ensure the effective utilization of cold storage forklift truck, good rate and service life.