流體引起的振動ppt課件-文庫吧資料
2025-05-07 06:33本頁面
【正文】 sturbances might be caused by obstructions in the duct or pipe, sharp right angle turns, abrupt changes in diameter, etc. 當(dāng)有某種東西干擾或阻礙流體在泵、風(fēng)機(jī)、壓縮機(jī)或真空泵中正常流動時，紊流就會發(fā)生。然而，若回流引起的振動過高，會損壞軸承、磨損環(huán)、閥和其它相關(guān)部件。SKF Slide 14 [Code] SKF [Organisation] Recirculation Characteristics 回流特點(diǎn) 1. Recirculation generates vibration spectra very similar to those caused by cavitation. That is, it will often have random, higher frequency vibration, sometimes superimposed with vane pass frequencies. 回流頻譜與氣蝕頻譜非常相似，也有隨機(jī)寬帶振動，有時還有葉片通過頻率。兩個或多個反向的液流會引起噪聲和振動。 When it occurs, a portion of the fluid returns from the discharge to the impeller as the pump attempts to move an excessive amount of fluid through the pump. This brings about a reverse flow and results in 2 or more fluids moving in opposite directions causing noise and vibration. 回流發(fā)生時，一部分流體會從出口回流到葉輪中，因?yàn)楸脤?shí)際上在輸送過多的流體。SKF Slide 13 [Code] SKF [Organisation] Recirculation 回流 In the case of a pump, recirculation is just the opposite of cavitation. Recirculation can occur when a pump is operated at too low a capacity or too high suction pressure. 對于泵來講，回流是與氣蝕相反的問題。典型的抽空頻譜與氣蝕頻譜幾乎完全一樣。中等程度的氣蝕產(chǎn)生的噪聲象沙子在泵中流動，而嚴(yán)重的氣蝕產(chǎn)生的噪聲象小石子在泵中通過。 20220529 169。SKF Slide 11 [Code] SKF [Organisation] Cavitation Characteristics 氣蝕特點(diǎn) 1. Classic spectra indicating cavitation have random, broad band energy most often between approximately 20,000 CPM up through approximately 120,000 CPM. 通常在 300Hz至 2,000Hz的頻率范圍內(nèi)有隨機(jī)寬帶的振動。SKF Slide 10 [Code] SKF [Organisation] Typical Spectrum of Cavitation amp。 在泵輸送量過大或入口壓力偏低條件下，泵容易產(chǎn)生氣蝕。SKF Slide 9 [Code] SKF [Organisation] Cavitation and Starvation 氣蝕與抽空 Cavitation is a mon problem with centrifugal pumps and can be quite destructive to internal pump ponents. Often, pumps subjected to continuing cavitation will have badly pitted and/or eroded impellers. In some cases, cavitation can pletely erode away impeller vanes. Cavitation most often occurs when a pump is operating with excess capacity or low suction pressure. 氣蝕是離心泵的常見問題，經(jīng)常造成泵內(nèi)
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