Elevator noise is one of the common residential noises at present. The occasions where elevators are used, such as residential buildings, shopping malls, hospitals, office buildings, etc., will have varying degrees of elevator noise impact. It is more difficult to control the noise of machine room elevators. The shaft is narrow and the noise reduction equipment is inconvenient for the transportation and installation. Today we will take a look at the noise control methods of machine room elevators.
1. Noise analysis of elevator without machine room
The noise of machine roomless elevators is usually relatively large, and the noise mainly includes motor current noise, motor brake noise, and contactor relay noise. The main equipment of the machine roomless elevator is installed on the hoistway. The vibration of the main machine will cause the transmission of vibration and noise of the building structure, so it is not recommended to use the machine roomless elevator in residential buildings.
2. Noise control plan for machine roomless elevators
Elevator noise pollution is different from general noise conditions. It belongs to low-frequency noise pollution, accompanied by slight vibration pollution. The main transmission route is solid-state sound transmission, while the general noise is air as the sound transmission medium. Reinforced concrete slab is a high-density substance, low-frequency sound propagates in it, with fast speed and low attenuation. In view of the above characteristics, the following treatment measures are taken.
1. The original elevator main engine and the foundation of the power distribution cabinet are rigidly connected to the reinforced concrete of the building, which becomes the main transmission "sound bridge" of elevator noise. The original foundation was transformed into a composite broadband K-value (neck coefficient) vibration reduction and noise reduction foundation to isolate the propagation path of low-frequency noise;
2. The electromagnetic radiation noise of the power distribution cabinet is also one of the strong pollution sources. The composite foundation with the lowest excitation frequency of 1HZ is used for the foundation of the power distribution cabinet; the incoming and outgoing wires are treated with soft contact, and the rigid connection between the building and the floor is disconnected to form a "sound bridge" , Cut off electromagnetic low-frequency noise from the source;
3. Based on the low-frequency noise components and characteristics of the elevator, the ratio of structural resonance transmission value to airborne sound energy is 200:1. In addition, the sound insulation of the wall is generally above 50dB, so sound insulation and absorption measures are added according to the sound insulation of the common wall of the elevator main room.
It is relatively difficult to control the noise of machine-room-less elevators, and it takes more time to control the noise. Therefore, it is generally recommended to conduct noise control during the elevator installation stage to avoid causing the elevator to stop for a long time and affect the normal life of users.