PPE

Harm of welding noise and protective measures

The fundamental way to control the noise is to control the sound source, and the effective way to control the sound source is to reduce the radiated sound source power. 1n industrial and mining enterprises, we often encounter various types of noise sources, their noise mechanism is different, and the noise control technology is also different. Next, according to the different physical properties of noise, the control technology is introduced< 1. Mechanical noise control technology mechanical noise is caused by vibration or collision of various mechanical parts excited by external force. The main methods to control the mechanical noise are as follows: improve the balance accuracy of the rotating parts and reduce the periodic excitation force of the rotating parts; On the contact surface of solid parts, elastic materials with different characteristic impedances are added to reduce solid sound transmission; Shock absorbers are installed on the parts with large vibration to isolate vibration and reduce noise transmission; Using materials with high internal loss coefficient to make parts with high noise in mechanical equipment, or adding damping on the surface of vibrating parts can reduce the acoustic radiation efficiency; 1mprove the machining accuracy and finish of moving parts, select appropriate work difference, control the gap between moving parts, reduce the vibration amplitude of moving parts, take enough lubrication to reduce friction; Avoid the impact and collision of moving parts, reduce the impact force and speed between the impact parts, and extend the impact time between the impact parts; Welding instead of riveting, rolling press and air press instead of knocking, silent hydraulic or extrusion instead of stamping, press instead of forging hammer2. Control of airflow noise airflow noise is caused by the interaction between airflow and solid medium in the process of airflow. The main methods to control airflow noise are as follows: selecting appropriate aerodynamic mechanical design parameters to reduce airflow pulsation and periodic excitation force; 1n order to reduce the turbulence noise, the air velocity and the sudden change of air pressure are reduced; Reduce high pressure gas discharge pressure and speed; 1nstall a suitable muffler< 3. Electromagnetic noise control electromagnetic noise is mainly caused by periodic vibration of metal parts and air excited by alternating electromagnetic fields the main measures to reduce motor noise are: reasonable selection of groove number and stage; Some epoxy resin materials are filled in the rotor groove to reduce vibration; 1ncrease the rigidity of stator; 1mprove the stability of power supply; 1mprove manufacturing and assembly accuracy the main measures to reduce the electromagnetic noise of transformer are: reducing the magnetic line density; Choose low magnetic silicon steel material; The core structure should be selected reasonably, the core gap should be filled with resin material, and the silicon steel sheet should be pasted with resin material< (2) transmission path control technology usually, due to some technical and economic reasons, it is difficult to control the noise from the sound source, so noise reduction measures should be considered from the transmission path. The specific methods are as follows: 1. Sound absorption and noise reduction when the sound wave is incident on the surface of the object, part of the incident sound wave can be absorbed by the surface of the object and converted into other energy, which is called sound absorption. Sound absorption and noise reduction is a method to control the noise intensity in the transmission path. The method is usually to install sound-absorbing materials on the indoor wall or ceiling surface< Muffler

< br / / (2) the sound insulation earmuff or earplug worn by the operator can achieve better protection effect (3) noise elimination materials can be temporarily set around the working face, which also has a certain effect China labor insurance net

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