What are the safety and protection operations of high-frequency welding using induction heating?
Induction brazing involves placing the brazed parts in an alternating magnetic field produced by the induction coil and heating the weldment by induction current. The intensity of the induced current is proportional to the frequency of the alternating current in the induction circuit. The higher the frequency, the greater the induction current, the faster the heating rate. However, the higher the frequency is, the more obvious the skin effect of the induced current is, and the thinner the heating thickness is, the thermal conductivity of the weldment itself depends on the material itself. In addition, the current penetration depth and the resistivity and permeability of. The higher the resistivity, the greater the penetration depth of the current. Therefore, when brazing materials with different physical properties, different induction current frequencies should be selected for heating.
The harm of high frequency electromagnetic field to human body is mainly caused by dysfunction of central nervous system and sympathetic nervous system. The main symptoms are dizziness, headache, malaise, fatigue, insomnia, forgetfulness, irritability, low working efficiency, and sweating, hair loss, weight loss and other symptoms occur. But the function of the obstacles, not to implement qualitative sex change, as long as from the work site for a period of time, the body can be restored to normal, to take certain protective measures can avoid the harm of high frequency electromagnetic field on the human body.
High frequency induction heating power supply in the process of high frequency electromagnetic field leakage seriously, the surrounding environment constitutes electromagnetic wave pollution. It mainly includes two aspects: radio wave interference and the harm to people's health. At the same time, the intensity of pollution is directly proportional to the power of the high-frequency power supply. Therefore, in induction brazing, it is necessary to take strict protective measures against the leakage of high frequency electromagnetic field, which has reduced the pollution to the environment and human body, so that it can reach harmless level.
The production practice shows that the current and frequency range of induction brazing is wide and can be used between 10~460KHz. At present, high frequency power supply including thyristor rectifier, high-frequency power supply and vacuum tube type high-frequency power supply can be used for induction brazing.
The production practice shows that the most effective protection for the high-frequency heating power is to effectively shield the leaked electromagnetic field. Usually, the whole screen is used, and the high frequency equipment and feeder, induction coil and so on are all placed in the shielding room. Operators operate inside and outside the screen.
