身處羅茨鼓風機領域得人應當都懂，噪聲是羅茨鼓風機生產制造的一項必要性指標值，早已造成廣泛關注。羅茨鼓風機噪聲一直是無法解決的問題，目的是為了根據電磁感應、機械設備、自然通風三方面要素一同危害。對于羅茨鼓風機噪聲的降低**的方法是：尋找噪聲形成的根本原因，或使用一些科技手段消弱羅茨鼓風機的噪聲。下邊我就降低羅茨鼓風機噪聲的方式，為大伙兒做一個簡單介紹吧：

　　一.從聲源處下手，降低噪聲羅茨鼓風機減噪*壓根的方法是以聲源處下手，選用一些消音器、隔音、吸音、減振等基本的降低噪聲的技術性。

　　1.降低排氣管噪聲。排氣管噪聲是發電機組*主要的噪聲源，其特點是噪聲級高，排氣管速度更快，整治難度大。選用精制的抗阻型復合型的消音器，一般可讓排氣管噪聲降低40-60db(a)。

　　2.降低軸流式風機噪聲。降低發羅茨鼓風機組冷卻風機噪聲時，務必考慮到兩個問題，一是排氣管安全通道所容許的壓力損失。二是規定的消音量。對于以上二點，可采用阻性管式消音器。

　　3.主機房的隔音、吸音解決和發電機組減振

　　(1)主機房隔音。設備的排氣管噪聲和冷卻風機噪聲降低以后，剩下來的關鍵噪聲源是羅茨鼓風機械噪聲。選用的方法是什么除需要的與隔離室相互連接的墻內視窗以外，其它窗子均去除，全部孔、洞要密實度堵漏，墻體墻面的隔音性規定要40db(a)之上。計算機房窗門選用防火安全隔音窗門。

　　(2)進風和排風系統。數據中心隔音解決以后，要處理主機房內排風排熱難題。進氣口應與羅茨鼓風機組、排風口設定在同一平行線上。進氣口應配以阻性管式消音器，因為進氣口壓力損失亦在允許范圍內，能使主機房內出入排風量當然做到均衡，自然通風排熱效果明顯。

　　(3)吸音解決。主機房內除路面外的五個邊界層能作吸音解決，依據羅茨鼓風機組的頻域特點選用穿孔鋁板共震吸音構造。

　　(4)室內環境的溝通交流，主機房的優良隔音，會讓羅茨鼓風機組關機機會屋內的氣體無法得到熱對流，屋內的持續高溫亦無法立即降下去，可選用低噪聲軸流式風機，另配上阻性管式消音器就能夠解決困難。

　　(5)發電機組減振。羅茨鼓風機組組裝前，應嚴苛按生產廠家供應的相關材料開展減振解決，規避導致構造聲的長距離散播，請在散播中持續輻射空氣聲，沒法使大氣污染物噪聲級合格。對因不合格而規定整治的目前羅茨鼓風機組，需要評測發電機組周邊路面的震動狀況，假如振感顯著，則需先對羅茨鼓風機組開展減振解決。

　　二.羅茨鼓風機噪聲一直是無法解決的問題，

　　目的是為了根據電磁感應、機械設備、自然通風三方面要素一同危害。在安裝羅茨鼓風機的情況下，應用幾類處理辦法針對抑止羅茨鼓風機機械設備噪聲較為合理。

　　1.電機轉子軸力造成的噪聲。當定轉子軸力時，會造成單側磁抗拉力噪聲：

　　a.電動機軸兩邊噪聲比較大

　　b.切斷電源后立刻消退

　　c.響聲相對穩定

　　當發生之上狀況時，理應各自查驗電機轉子鐵芯相對于兩邊軸承臺的圓柱度和電動機軸兩邊槽口相對于電機定子鐵芯的平行度。

　　(1)假如是電機轉子軸力，可根據以軸承臺為標準，重打中心孔后再光(磨)電機轉子的方法來處理

　　(2)假如是電機定子軸力，能夠電動機軸槽口為標準車圓電機定子鐵芯公稱直徑。

　　需要注意的是：不管哪種方法，都是會擴大磁密，這可能使功率因數減少。因而加工量需把控在0.3mm之內。適度**磁密能夠降低諧波電流電磁場的幅度值，降低磁密的不勻稱度并能使徑向力波的幅度值降低，都可讓噪聲隨著降低。

　　2.軸承軸向側隙的調節。

　　軸承的軸向工作中側隙是造成軸承噪聲的主要原因，尤其是軸承軸向工作中側隙小了或無空隙運作，噪聲超標準更加突顯。從實驗獲知：H560-H355的軸承軸向裝配間隙(軸承孔與軸承中間)確保在0.013-0.028mm的范圍之內，就可基本上清除無空隙或間隙小了運作，軸承噪聲顯著降低。

　　3.改裝消聲罩。

　　目的是為了用于降低自然通風噪聲。在大中小型羅茨鼓風機中，消音罩通常加進通風管道的前面。吸音材料襯層薄厚取50-70mm，吸音材料選用塑料泡沫或者海棉，消音罩的效果明顯。

　　總的來說，為了能降低羅茨鼓風機噪聲，除開從聲源處下手外，還能夠選用科學合理、**的加工工藝對策，這針對降低羅茨鼓風機噪聲全是有益的，使羅茨鼓風機品質獲得確保。結合我廠售后部門的維修維護經驗，我們總結出了兩種短期內有效控制羅茨鼓風機噪音的方法！

　　有效控制羅茨鼓風機噪聲*壓根的方法由下面二種：

　　1.羅茨風機改裝隔聲罩

　　1)將隔聲罩進風口部位挪到罩體下邊，是隔聲罩內氣旋產生連續流，并通過電機和離心風機人體開展制冷

　　2)隔聲罩進風口擴大至600mm*250mm，降低進氣口摩擦阻力減少羅茨離心風機負載。

　　3)隔聲罩進風口由戶外送風改成房間內送風，禁燒自然通風摩擦阻力，改進風機房自然通風情況。

　　4)風機房內**排風扇，將隔聲罩內熱氣直接排放戶外，排氣扇安裝消音器;請在在其中設定止逆閥。

　　2.對風機房開展隔音降噪提高。

　　1)風機房門改成隔音門，設計方案隔音性為30聲貝，原鋼質門隔音性不夠10聲貝

　　2)西邊窗子改成隔聲窗，為降低成本費在原來窗子里側改裝固定不動窗戶，正中間做隔聲解決。

　　3)風機房撞南墻下邊進氣口設定消音進箱式風機。進氣口合理離心風機依據3臺羅茨離心風機需要進排風量明確。

　　4)撞南墻兩部排風扇改成低噪聲排氣管上，并裝有消音器，排風扇為降低室內氣溫應用。

　　該羅茨離心風機減噪新項目解決完成后，通過檢驗，在3臺開全很有可能較大工作狀況下，風機房均值噪聲即將到來76聲貝，監控室挨近風機房噪聲即將到來62聲貝，大氣污染物噪聲即將到來47聲貝，超過我國有關自然環境噪聲規范！

　　People in the field of Roots blower should understand that noise is a necessary index value for the production and manufacture of Roots blower, which has already caused widespread concern. The noise of Roots blower has always been a problem that cannot be solved. The purpose is to do harm together according to electromagnetic induction, mechanical equipment and natural ventilation. The way to reduce the noise of Roots blower * * is to find the root cause of the noise, or use some scientific and technological means to weaken the noise of Roots blower. Next, I'll give you a brief introduction on how to reduce the noise of Roots blower:

　　I Starting from the sound source, the most fundamental way to reduce the noise of Roots blower is to start from the sound source, and select some basic noise reduction techniques such as muffler, sound insulation, sound absorption, vibration reduction, etc.

　　1. Reduce the noise of exhaust pipe. Exhaust pipe noise is the main noise source of generator set, which is characterized by high noise level, faster exhaust pipe speed and great difficulty in remediation. The noise of the exhaust pipe can generally be reduced by 40-60db (a) by selecting a refined resistance composite muffler.

　　2. Reduce the noise of axial flow fan. When reducing the noise of the cooling fan of the roots blower unit, two problems must be considered: one is the allowable pressure loss of the safety channel of the exhaust pipe. The second is the specified volume reduction. For the above two points, the resistive pipe silencer can be used.

　　3. Sound insulation and absorption of main engine room and vibration reduction of generator set

　　(1) Sound insulation of main engine room. After the exhaust pipe noise and cooling fan noise of the equipment are reduced, the remaining key noise source is roots blower machinery noise. What is the method selected? Except for the window in the wall that needs to be connected with the isolation room, other windows should be removed, all holes and holes should be sealed with compactness, and the sound insulation of the wall should be above 40dB (a). The windows and doors of the computer room shall be fireproof, safe and sound proof.

　　(2) Air intake and exhaust system. After the sound insulation of the data center is solved, the problem of air and heat exhaust in the host room should be solved. The air inlet shall be set on the same parallel line with roots blower unit and exhaust outlet. The air inlet should be equipped with a resistive pipe muffler, because the pressure loss of the air inlet is also within the allowable range, which can naturally balance the air volume in and out of the main engine room, and the natural ventilation and heat removal effect is obvious.

　　(3) Sound absorption solution. The five boundary layers in the main engine room except the road surface can be used for sound absorption. According to the frequency domain characteristics of Roots blower unit, perforated aluminum plate co vibration sound absorption structure is selected.

　　(4) The communication of the indoor environment and the excellent sound insulation of the main engine room will make the roots blower unit shut down. The gas in the house cannot get thermal convection, and the continuous high temperature in the house cannot be reduced immediately. You can choose a low-noise axial-flow fan and add a resistive pipe muffler to solve the problem.

　　(5) Vibration reduction of generator set. Before the assembly of Roots blower unit, the vibration reduction solution should be strictly carried out according to the relevant materials supplied by the manufacturer to avoid the long-distance spread of structural sound. Please continue to radiate air sound in the spread, which cannot make the noise level of air pollutants qualified. For the current roots blower units that are required to be rectified due to disqualification, it is necessary to evaluate the vibration condition of the road around the generator unit. If the vibration is significant, it is necessary to carry out vibration reduction for Roots blower units first.

　　II The noise of Roots blower has always been an unsolvable problem,

　　The purpose is to do harm together according to electromagnetic induction, mechanical equipment and natural ventilation. In the case of installing roots blower, it is reasonable to apply several kinds of treatment methods to suppress the noise of Roots blower mechanical equipment.

　　1. Noise caused by motor rotor axial force. When the stator and rotor shaft force, it will cause unilateral magnetic anti tension noise:

　　a. The noise on both sides of the motor shaft is relatively large

　　b. Immediately fade after cutting off the power supply

　　c. The sound is relatively stable

　　When the above situation occurs, it is necessary to check the cylindricity of the motor rotor core relative to the bearing platforms on both sides of the shaft and the parallelism of the slots on both sides of the motor shaft relative to the motor stator core.

　　(1) If it is the axial force of the motor rotor, it can be handled according to the method of taking the bearing platform as the standard, re punching the center hole and then polishing (grinding) the motor rotor

　　(2) If it is the axial force of motor stator, the slot of motor shaft can be the nominal diameter of stator core of standard turning motor.

　　It should be noted that either method will expand the magnetic density, which may reduce the power factor. Therefore, the processing volume should be controlled within 0.3mm. Moderately increasing the magnetic density can reduce the amplitude value of harmonic current electromagnetic field, reduce the asymmetry of magnetic density and reduce the amplitude value of radial force wave, which can reduce the noise.

　　2. Adjustment of axial clearance of bearing.

　　The side clearance of bearing in axial operation is the main cause of bearing noise, especially when the side clearance of bearing in axial operation is small or there is no clearance, the noise exceeding the standard is more prominent. It is learned from the experiment that the axial assembly clearance (between the bearing hole and the bearing) of the bearing of h560-h355 is ensured to be within the range of 0.013-0.028mm, which can basically eliminate the operation without clearance or with small clearance, and the bearing noise is significantly reduced.

　　3. Refit the muffler.

　　The purpose is to reduce the noise of natural ventilation. In large, medium and small roots blowers, the muffler is usually added in front of the ventilation duct. The thickness of the sound-absorbing material lining is 50-70mm. The sound-absorbing material is plastic foam or sponge, and the effect of the muffler is obvious.

　　In general, in order to reduce the noise of Roots blower, in addition to starting from the sound source, scientific, reasonable and excellent processing technology countermeasures can also be selected, which is beneficial to reduce the noise of Roots blower and ensure the quality of Roots blower.

　　There are two ways to effectively control the noise of Roots blower:

　　1. Refit the sound insulation cover of roots centrifugal fan

　　1) Move the air inlet of the sound insulation cover to the lower side of the cover, because the cyclone in the sound insulation cover generates continuous flow, and refrigeration is carried out by the motor and centrifugal fan

　　2) The air inlet of the acoustic enclosure is expanded to 600mm*250mm to reduce the friction resistance of the air inlet and reduce the load of roots centrifugal fan.

　　3) The air inlet of the acoustic enclosure is changed from outdoor air supply to indoor air supply, and the friction resistance of natural ventilation is prohibited, so as to improve the natural ventilation of the fan room.

　　4) The exhaust fan is lifted in the fan room to directly discharge the hot gas in the sound insulation hood outdoors, and the exhaust fan is installed with a silencer; Please set the check valve in it.

　　2. Improve the sound insulation and noise reduction of the fan room.

　　1) The fan room door is changed into a sound proof door. The sound insulation of the design scheme is 30 sound shells, and the sound insulation of the original steel door is not enough to 10 sound shells

　　2) The west window is changed into a sound insulation window. In order to reduce the cost, the fixed window is refitted on the inner side of the original window, and the sound insulation is done in the middle.

　　3) The silencing box type fan is set at the air inlet under the south wall of the fan room. The reasonable air inlet of centrifugal fan is determined according to the inlet and exhaust air volume of three roots centrifugal fans.

　　4) The two exhaust fans on the south wall are changed into low-noise exhaust pipes and equipped with silencers. The exhaust fans are used to reduce indoor temperature.

　　After the completion of the new project of noise reduction of roots centrifugal fans, the inspection showed that under the working condition that the three fans are likely to be fully opened, the average noise of the fan room is about to reach 76 sound decibels, the noise of the monitoring room close to the fan room is about to reach 62 sound decibels, and the noise of air pollutants is about to reach 47 sound decibels, exceeding the relevant natural environmental noise norms of our country!