动态分离器技术介绍Introduction of Dynamic Classifier Technology 随着电力事业的快速发展,世界各国对电厂环保的要求越来越高,许多机组都在使用低NO x排放技术。
为了降低NOx和飞灰排放量又不增加运行成本,作为锅炉系统重要辅机的磨煤机也相应进行了技术改进,采用了动态分离器技术。
With the rapid development of electric power project,most countries begin to think much of the environment. As a result, many units are incorporating infurnace low NO x technology. For reduceing the NOx and ash and without disposal cost, pulverizer that is one of the most important assistant equipment of the boiler system have been improved and equipped with Dynamic Classfier .HP磨煤机配套的动态分离器装置主要包括以下几个部分:The primary components of the Dynamic Classifier are:1.轴承和驱动装置 Bearing and Drive Assembly2.变频电机和涡轮蜗杆减速器Variable Frequency Motor and Worm Gear Reducer3.V带V-Belt4.变频器Pulse Width Modulated Variable Frequency Drive(VFD)5.转子装置Rotor Assembly动态分离器使用一对脂润滑角接触球轴承,轴承放置在结构件制成的轴承座中,上、下轴承各有一个热电阻用于监测轴承温度。
为了保护轴承,上、下各有一个油封。
迷宫气封的设计也是为了防止粉尘进入驱动装置。
The Dynamic Classifier use two grease lubricated angular contact ball bearings installed in fabricated steel housing.There are two thermocouples to monitor the temperature of the two ball bearings.To protect the bearings,upper and lower oil seals are byrinth design air selas are also used to seal the drive assembly from coal dust.变频电机和涡轮蜗杆减速器通过联轴器连在一起,变频电机通过变频器改变频率从而改变转速。
涡轮蜗杆减速器输出轴上安装主动轮,通过皮带带动与转子装置连接在一起的从动轮,从而使转子转动。
转子的旋转方向为从磨煤机上方往下看为顺时针方向。
The Variable Frequency Motor and Worm Gear Reducer are connected by a coupling.The frequency of the motor is changed by the VFD and then the speed of the rotor can be changed.A driver sheave is assembled at the output shaft of the worm gear reducer,and it drives the drived sheave which is connected with the rotor assembly ,and so the rotor can rotate.The Dynamic Classifier Rotor is designed to rotate in a clock-wise direction when viewed from above the mill.变频器采用成熟技术制成,与机械变速相比,变频器几乎不用维护,可靠性很高。
VFD have high reliability using proven technology with little or no required maintenance as compared to mechanical speed control.转子采用耐磨合金钢制成,整体锥形结构,设计寿命超过50000小时。
The rotor design is a multi bladed rotor with a basic conical shape.It is fabricated from an abrasion resistant alloy steel and designed with lives exceeding 50,000 hours. 带动态分离器HP磨煤机的工作理:HP磨煤机的主要功能是将直径小于等于38mm的原煤研磨成0.075mm左右的煤粉,供锅炉燃烧。
热一次风(用来干燥和输送磨煤机内的煤粉)从磨碗下部的侧机体进风口进入,并围绕磨碗毂向上穿过磨碗边缘的叶轮装置,旋转的叶轮装置使气流均匀分布在磨碗边缘并提高了气流的速度,与此同时,煤粉和气流就混合在一起了,气流携带着煤粉冲击固定在分离器体上的固定折向板。
颗粒小且干燥的煤粉仍逗留在气流中并被携带沿着折向板上升至分离器,大颗粒煤粉则回落至磨碗被进一步碾磨,分离器体下部的固定折向板使煤粉在碾磨区域进行了初级分离。
Operation principle of HP mill with with Dynamic ClassifierThe primary function of HP mill is to grind coal from diameter≤38mm to diameter 0.075mm and send ground coal to boiler for burning.The hot primary air enters mill from the air inlet of millside and pass through the vane wheel assembly encircling the bowl hub.The rotating vane wheel assembly directs, equalize and accelerates the primary air.And at the same time the coal and air mix.As the coal-air mixture rises up through the separator body ,the initial classification occurs when theheaviest particles lose their momentum and fall back to the bowl for regrinding.煤粉和气流上升,通过分离器体进入旋转的叶片式转子,在转子外沿处,气流和煤流相互作用,转子会阻止较大颗粒通过,使较大颗粒返回磨碗进一步碾磨,而细度合格的煤粉则可以通过转子排出磨煤机。
通过变频器和变频电机可以改变转子的转速,通过改变转子的转速可以调整煤粉的细度。
the coal-air mixture risesup to through the spinningrotor.At the outside face of therotor,the air and the coalstream interact with therotor.The rotor rejects thelarger particles and sends themback to the grinding zone forfurther size reduction whilethe samller particles are permitted to pass through the rotor and exit the mill through the discharge valves.Finess is varied by changing the speed of the rotor.This is done by means of avariable speed motor and variable frequency drive.带动态分离器的磨煤机由于内循环负荷比静态分离器小,所以能够提高磨煤机出力,这是由于分离效率提高实现的,就是说避免了细小颗粒(粒度小于200目的)不必要的重新碾磨次数,这样合格的煤粉就可以较快的排出磨煤机。
也就是说:相同的煤质和细度要求下可以提高磨煤机出力;或者相同的煤质和出力要求下可以提高煤粉细度。
The addition of a Dynamic Classifier to a pulverizer results in an increase in capacity due to a reduction in the recirculation load created by the classifier. The reason for thes increase in capacity is the change in classification in efficiency.That is ,unnecessary over-grinding of the very small particles (those less than 200 mesh ) isreduced, thus properly sized particles are discharged quicker with the Dynamic Classifier. The increase in capacity can be utilized in one of two ways: an increase in coal flow for constant coal properties and constant tineness,or increased fineness capability for constant coal properties and coal flow.HP磨煤机采用动态分离器后煤粉颗粒分布关系:Distrubuting of coal ground by HPmill with Dynamic ClassifierHP1003/Dyn磨煤机动态分离器技术参数HP1003/Dyn mill Dynamic Classifier technical data1. 变频电机额定功率 45kWRated power of variable frequency motor 45kW2. 变频电机频率 16.7~50HzFrequency of variable frequency motor 16.7~50Hz3. 转子转速 30~130 rpmSpeed of rotor 30~130 rpm4. 煤粉细度 R=5%~35%90Coal finess R90=5%~35%动态分离器的操作和维护动态分离器的控制要根据给煤量和现场调试时绘制出的校准曲线来确定转子转速。