There is a fire risk in the production process of

There is fire risk in the production process of motor and the corresponding preventive measures

the process of motor production is very complex, including shell production, coil winding and wire embedding, coil impregnation treatment, etc. Among them, fire can be used for tensile test, pressure test and bending test. The most dangerous is the coil impregnation process, which mainly includes three processes: pre drying, paint dipping and drying

1. Fire hazard

(1) a large amount of static electricity will be generated during the filtration, dumping and mixing of the impregnation solution. If it is not released in time and accumulates into high-voltage static electricity, it will cause danger

(2) when the electric heating method is used for pre drying, if the temperature rise is out of control, it may cause a fire

(3) a large number of flammable and combustible gases will be produced during the process of thermal impregnation and pre drying. When the concentration reaches a certain level, it is very easy to burn and explode in case of open fire or arc. When vacuum pressure impregnation method is adopted, because inert gas is not used for protection, high-pressure mixed gas may explode once it reaches its explosion limit in repeated recycling

(4) the drying operation is too rapid, the coil droplets after impregnation can be dried before they are dry, and the residual liquid dripping when drying with electric heating wire may cause a fire

2. Prevention

(1) it is best to use steam heating or vacuum heating in the pre drying process, and control the temperature and time of pre drying according to the heat-resistant grade of insulating materials, pre drying equipment and coil structure, so as to prevent fire hazards caused by too high pre drying temperature and too long pre drying time

(2) when the hot dip method is used for paint dipping operation, the hot dip workshop should be a building with grade I and II fire resistance rating, the room should be well ventilated, and the fan impeller should be made of non-ferrous metal. All open flames and spark generating operations are strictly prohibited in the workshop. All electrical equipment should meet explosion-proof requirements and be well grounded. When cleaning the mandrel with toluene, operate gently to prevent splashing, and do not wipe the mandrel with synthetic fiber. Large rotors should be hoisted by crane, and the crane should run slowly and steadily. The paint and thinner in the paint tank should not be too full, and the paint dirt dripping on the floor should be removed timely and regularly. The paint cylinder shall be covered and placed, and the workpiece shall be covered immediately after being taken out. The soaked workpiece should be placed in a ventilated place to dry before drying

(3) when using vacuum pressure method for paint dipping operation, in addition to the fire prevention requirements of hot dipping method, attention should also be paid to: select inert gas for pressurization; The paint solution used for impregnating lithium titanate, lithium titanium phosphate, negative electrode materials, etc. should be tested and filtered frequently to eliminate impurities; When pouring the paint liquid, it should be filtered with metal, the pouring amount should be small, and the mixing should be slow to avoid static electricity

(4) when drying, the drying room should maintain good ventilation conditions. If mechanical ventilation is adopted, shaft 2 and weight measuring flow blower shall adopt explosion-proof device. The hot air sent to the drying room shall not be recycled, and the drying room shall be equipped with a spring door without a bolt. It is best to use steam heating, hot air drying or vacuum drying and other drying methods, and avoid using electric heating wire drying to reduce the fire risk. When electric heating wire must be used for heating, the electric heating wire should be completely separated from the workpiece, and the temperature should be measured every other hour to prevent the soaking liquid from dripping on the electric heating wire and causing combustion. The drying temperature should be stable from low to high, so that the solvent can evaporate slowly and will not form an explosive mixture. The maximum temperature during drying shall not exceed the heat-resistant allowable temperature of the insulating material

(5) during the maintenance of the drying room, the relevant approval procedures should be handled before the hot work, and it can be carried out only with the consent. The hot work maintenance room should be well ventilated, and all hot work equipment pipelines close to the tank immersion equipment room should be removed. 3. Nano metal materials. The immersion tank must be vacuumed, and the paint tank must be removed from the hot work inspection site

(6) unit operations with similar production properties, such as pre drying, paint dipping, drying, etc., should be concentrated in the same fire-proof building to facilitate production and management

(7) paint materials, thinners, etc. required for on-site impregnation should be received as soon as they are used according to the dosage, and their storage time should generally not exceed one day. After use, it should be sealed and stored in metal containers