離心風(fēng)機(jī)是依據(jù)動(dòng)能轉(zhuǎn)換為勢(shì)能的原理,應(yīng)用高速旋轉(zhuǎn)的葉輪將氣體加速,然后減速、改動(dòng)流向,使動(dòng)能轉(zhuǎn)換成勢(shì)能(壓力)。在單級(jí)離心風(fēng)機(jī)中,氣體從軸向進(jìn)入葉輪,氣體流經(jīng)葉輪時(shí)改動(dòng)成徑向,然后進(jìn)入擴(kuò)壓器。在擴(kuò)壓器中,氣體改動(dòng)了活動(dòng)方向并且管道斷面面積增大使氣流減速。
According to the principle that kinetic energy is converted into potential energy, centrifugal fan uses high-speed rotating impeller to accelerate the gas, then decelerates and changes the flow direction, so that kinetic energy is converted into potential energy (pressure). In a single-stage centrifugal fan, the gas enters the impeller from the axial direction, changes to the radial direction when passing through the impeller, and then enters the diffuser. In the diffuser, the movement direction of the gas is changed and the cross-section area of the pipe is increased to slow down the gas flow.
這種減速作用將動(dòng)能轉(zhuǎn)換成壓力能。壓力增高主要發(fā)作在葉輪中,其次發(fā)作在擴(kuò)壓過程。在多級(jí)離心風(fēng)機(jī)中,用回流器使氣流進(jìn)入下一葉輪,產(chǎn)生更高壓力。離心風(fēng)機(jī)本質(zhì)是一種變流量恒壓安裝。當(dāng)轉(zhuǎn)速一定時(shí),離心風(fēng)機(jī)的壓力-流量理論曲線應(yīng)是一條直線。由于內(nèi)部損失,實(shí)踐特性曲線是彎曲的。離心風(fēng)機(jī)中所產(chǎn)生的壓力遭到進(jìn)氣溫度或密度變化的較大影響。
This deceleration converts kinetic energy into pressure energy. The increase of pressure mainly occurred in the impeller, followed by the expansion process. In the multistage centrifugal fan, the air flow is sent into the next impeller with a reflux device to produce higher pressure. Centrifugal fan is essentially a variable flow and constant pressure installation. When the rotating speed is fixed, the theoretical curve of pressure flow of centrifugal fan should be a straight line. Due to internal losses, the practical characteristic curve is curved. The pressure produced in the centrifugal fan is greatly affected by the change of inlet air temperature or density.

對(duì)一個(gè)給定的進(jìn)氣量,進(jìn)氣溫度(空氣密度)時(shí)產(chǎn)生的壓力。關(guān)于一條給定的壓力與流量特性曲線,就有一條功率與流量特性曲線。當(dāng)鼓風(fēng)機(jī)以恒速運(yùn)轉(zhuǎn)時(shí),關(guān)于一個(gè)給定的流量,所需的功率隨進(jìn)氣溫度的降低而升高。
For a given intake volume, the highest intake temperature (lowest air density) produces the lowest pressure. For a given pressure and flow characteristic curve, there is a power and flow characteristic curve. When the blower is running at a constant speed, the required power increases with the decrease of inlet air temperature for a given flow.
磨損問題離心風(fēng)機(jī)傳動(dòng)部位磨損是常呈現(xiàn)的設(shè)備問題,其中包括抽風(fēng)機(jī)軸承位、軸承室磨損、鼓風(fēng)機(jī)軸軸承位磨損等。針對(duì)離心風(fēng)機(jī)上述毛病,傳統(tǒng)維修辦法有堆焊、熱噴涂、電刷渡等,但均存在一定弊端:補(bǔ)焊高溫產(chǎn)生的熱應(yīng)力無法完整消弭,易形成材質(zhì)損傷,招致部件呈現(xiàn)彎曲或斷裂;而電刷鍍受涂層厚度限制,容易剝落。
The wear problem of the transmission part of the centrifugal fan is a common equipment problem, including the wear of the bearing position of the suction fan, the bearing chamber, and the bearing position of the blower shaft. In view of the above problems of centrifugal fan, the traditional maintenance methods include overlay welding, thermal spraying, brush crossing, etc., but all of them have some disadvantages: the thermal stress generated by high temperature of repair welding can not be completely eliminated, and it is easy to form material damage, resulting in bending or fracture of parts; while brush plating is subject to the limitation of coating thickness, which is easy to peel off.
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