How to reduce the noise of rotary vane blowers?
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A Roots blower is a typical positive-displacement blower that converts the mechanical energy supplied by the prime mover into pressure and kinetic energy of the gas, through changes in the volume of the rotor. Compared with centrifugal blowers, it has advantages such as high head pressure, less influence of resistance on flow rate, and stable air supply, but it generally suffers from low efficiency and high noise levels during operation. Since fans generate significant noise that deteriorates working conditions and pollutes the living environment, there is an increasing focus on fan noise. Please discuss how to reduce the noise of rotary vane blowers
The Roots blower is equipped with a silencer, and it’s also very important to install additional noise-absorbing materials to ensure smooth operation. Yet even with these measures in place, the noise level remains high. Our solution was to build a dedicated room for it, installing noise-absorbing materials inside; by closing the door, the noise level can be significantly reduced
First, it is necessary to check for any issues with the Roots blower itself, such as the lubrication of the bearings, whether the blades are worn, whether the foundation is secure, and whether there are any blockages in the air ducts. Then, a dedicated silencer should be installed. I disagree with the view expressed on the second floor, as it is necessary to carefully analyze the medium transported by the Roots pump; if it is a flammable or explosive gas, as mentioned on the second floor, an accident could occur in the event of a leak.
Build a soundproof room. Try to keep the equipment in good condition.
Here we have units with small rooms, and there is sound-absorbing material inside. But the noise is still very loud. The medium is air, and the air intake filter tends to get clogged.
In coal chemical industry, can the fit dimensions between the gear hub and shaft of the Roots blower be increased?
A soundproof enclosure still needs to be installed; following the specifications should allow the noise level to be reduced below the standard
All the fans we import come with noise reduction chambers; if it’s convenient, consider modifying them
The noise problem associated with Roots compressors has always been a hassle. In our facility, there are no soundproof enclosures for the Roots compressors; although there are noise reduction rooms, the noise level remains quite high. I would like to get more information on such soundproof enclosures – could anyone provide some details? Thank you.
The inherent drawback of rotary vane fans is their high noise level. A common solution is to use soundproof enclosures, which helps meet environmental regulations; however, this makes inspections more difficult. Therefore, it is recommended to avoid using rotary vane fans and instead opt for centrifugal fans or similar alternatives.
It is a fact that rotary vane blowers generate a lot of noise. Some units use isolation chambers to reduce this noise, and the choice of equipment can also help; those with three vanes produce much less noise than those with two vanes.
The Roots blower comes with a silencer, but the noise is still quite high and unbearable. Its noise level remains at 140–160 decibels (with an outlet pressure of 30–40 KPa). Soundproofing the outlet of the Roots pump as well as the outlet ducts using sound-absorbing material can reduce the noise level to 90–100 decibels under the same load. The effect is pretty good.
I think we should start from the following aspects: First, the oxide scale and dirt on the fan rotor need to be removed to keep the rotor surface smooth and clean. Second, a silencer should be installed at the air inlet
The methods vary depending on the medium being transported. In coal chemical industries, where gas is transported, building a silencing chamber can be very dangerous; if the oil seal of the fan leaks, poor air circulation within the chamber increases the risk of accidents. It’s also not possible to use sound-dampening material at the outlet, as the medium in question is quite dirty. It gets clogged easily. Transporting air is easy to handle in any case
Just add a soundproof enclosure; in our case, the sound becomes very low once the door of that enclosure is closed
The medium we transport is a toxic gas, and there are numerous connecting pipelines, making it impossible to install soundproof rooms. It is better to adjust the gaps between the impellers and also between the impellers and the wall panels, and to install silencers to reduce the temperature. Are there any other good ways?
The main sources of noise generated by rotary vane pumps are: 1) aerodynamic noise radiated from the inlet and outlet (the primary source); 2) mechanical noise emitted by the casing, motor, bearings, etc.; 3) solid vibration noise resulting from foundation vibrations. Among them: pneumatic noise mainly includes rotational noise and vortex noise. Methods for controlling pneumatic noise: 1. Install silencers; 2. Create isolation enclosures; 3. Adopt sound-insulating measures in the fan room; 4. Wrap the pipes; 5. Use vibration isolation. The fundamental ways to reduce noise are: 1. Design the impeller as a twisted-leaf impeller; 2. Replace the impeller with a three-leaf impeller. Wait. Personal opinion.
Nowadays, **there are increasing demands for environmental protection; if the flow rate and pressure conditions permit, it is recommended to choose centrifugal fans, as they produce much less noise.**
Rotary vane blowers generate a lot of noise because they involve changes in volume. Since these machines are used, it’s impossible to avoid that noise; one can only try to reduce it. Nowadays, exhaust silencers are commonly used, along with sound-insulating enclosures, and this helps to keep the noise level below 80 DBA at a distance of 1 meter – which is considered quite good
We used a two-vane Roots blower with silencers at the inlet and outlet, and the entire blower was housed in a soundproof enclosure; yet the results were still not satisfactory. I plan to switch to a three-blade version; it’s much quieter than the two-blade one.
The noise level of the 20# scmn model with two blades is higher; for the version with three blades, a sound insulation cover is also necessary in order to reduce the noise level to below 80 bDA. I deal in the import of German fans, and we can discuss this further if needed