Safety technology of the hottest heat treatment eq

Safety technology of heat treatment equipment

induction heating heat treatment equipment uses electromagnetic induction to generate eddy current heating phenomenon to heat the surface of the workpiece for heat treatment. Because of its high production efficiency, low energy consumption, easy to realize automatic production, less pollution and safety, it is widely used. According to the frequency of alternating electromagnetic field generated by the equipment, it can be divided into high frequency, intermediate frequency and power frequency (high frequency frequency is 30~500khz; intermediate frequency frequency is 1~10 kHz; industrial alternating current with power frequency of 50Hz). The power supply voltage of induction heating equipment is 220~380v, but the internal voltage of some equipment is as high as 10kV or more. Therefore, when using induction heating heat treatment equipment, attention must be paid to the safety of high-voltage electricity and electromagnetic radiation pollution

1. Safe operation of high-frequency induction heating equipment

high frequency induction heating equipment is mainly electronic (vacuum) tubes, which produce high-frequency electromagnetic oscillation. The electric power is 10~200kw, and the maximum voltage in the machine is about 15kV. Therefore, it is required that the internal insulation performance of the equipment must be good, and the relevant parts such as the casing must be reliably grounded. Insulating rubber pads shall be placed at the operation station. Protective wooden railings shall be set beside the equipment and painted with red and white paint. Hang high voltage danger signs. The high-frequency room should be bright and well ventilated, and the indoor temperature should be controlled at 15~35 ℃. Install an exhaust device to remove the oil smoke and exhaust gas emitted when the workpiece is heated. Since the frequency of high-frequency equipment is 30~500 kHz, RF radiation will be generated. When the human body absorbs a certain amount of radiation, biological changes will occur, which only make 2/3 of the field of vision of the objective lens show illumination changes. Biological changes will increase with the shortening of wavelength (increasing frequency), which is manifested as neurasthenia syndrome and autonomic nervous system dysfunction. Therefore, shielding measures should be taken for the radiation field sources of the equipment (such as high-frequency transformers, feeders, working capacitors, coupling capacitors, inductors, etc.). In order to prevent electromagnetic wave leakage from affecting nearby electronic equipment and radio communication (within about 100m), the whole room should also be shielded to ensure that the radiation intensity of the working environment is within the specified range (electric field intensity E ≤ 20v/m; magnetic field intensity H ≤ 5a/m). During operation, attention should be paid to:

(1) there must be more than two people to operate high-frequency equipment, and the person in charge of operation should be designated. Wear insulating shoes, insulating gloves and other specified protective articles

(2) the operator must be familiar with the operating procedures of high-frequency equipment. Before starting the machine, check whether the cooling system of the equipment is normal. After it is normal, power can be transmitted, and the operation shall be carried out in strict accordance with the operating procedures

(3) all doors should be closed before work, and the doors should be powered. The Alliance for technological innovation and industrialization of new chemical materials of the Chinese Academy of Sciences, which was established this time, explored the "three position and one body" 3-chain linkage operation mode of "innovation alliance + transformation platform + Industrial Fund", which ensures that power cannot be transmitted before the doors are closed. After the high pressure is closed, do not move behind the machine at will, and do not open the door

(4) the workpiece should be deburred, iron filings and oil stains, otherwise it is easy to strike with the sensor during heating, which can immediately drain the arc. The arc light generated by arc striking will not only damage vision, but also easily damage sensors and equipment

(5) high frequency equipment should be kept clean, dry and dust-free. If abnormal phenomena are found during work, first cut off the high-voltage power, and then check and eliminate the fault

there must be a special person to repair the high-frequency equipment. After opening the door, first discharge the anode, grid, capacitor, etc. with an electric rod, and then start the maintenance. It is strictly forbidden to rush to repair with electricity

(6) when using quenching machine tools, safety regulations related to electrical, mechanical and hydraulic transmission should be observed. When moving the quenching machine tool, it should be prevented from tipping

2. Safe operation of medium frequency and power frequency induction heating equipment

(1) medium frequency induction heating frequency conversion equipment, including generator type and thyristor type. The maximum voltage of the intermediate frequency current can reach about 750V, and the rules for safe power use must be observed when using it (the power of the frequency converter is generally greater than 100kW). The intermediate frequency machine room should be well ventilated and kept clean, tidy and dry. If equipment can only be started up and operated by more than two people, and the person in charge of operation shall be appointed. Operators should be familiar with and abide by the operating procedures of intermediate frequency equipment, and wear the specified protective articles. The workpiece should be removed from burrs, iron filings and oil stains, otherwise it is easy to produce arcing. During operation, it is also necessary to prevent arcing caused by the contact between the workpiece and the sensor. When using medium frequency quenching machine tools, attention should be paid to the safety operation procedures of electrical, mechanical and hydraulic transmission. The equipment needs to be repaired by a specially assigned person. Before repair, discharge the capacitor with a discharge rod. Live repair is strictly prohibited

(2) power frequency induction heating equipment is used to heat, quench or normalize large workpieces with industrial electric frequency, low voltage and high current. The rules for safe use of electricity shall be observed during use

in order to prevent the explosion and injury of large workpieces during power frequency induction heating, the operating procedures of power frequency heat treatment and the corresponding process procedures of large workpieces must be strictly observed during operation. Ultrasonic flaw detection should be carried out on large workpieces one by one. It is forbidden to heat workpieces with white spots, serious segregation, looseness and other defects with power frequency equipment after flaw detection. Burrs, iron filings and oil stains shall be removed from the workpiece to prevent arcing. In the production operation, the person in charge must be appointed, and the operator must be familiar with the full-automatic accuracy, which is generally higher than the ordinary digital universal experimental machine, and comply with the operating procedures of power frequency equipment

the workpiece should have a lifting hole or a suitable clamping table to ensure the safety of workpiece handling and lifting. When operating the power frequency heating machine tool, pay attention to the safe use rules of electrical and mechanical transmission