当前位置:网站首页 > 新闻中心 > 行业资讯

N

新闻中心

  • 怎么样选择除尘器
  • 本站编辑:四川国清源环保科技有限公司发布日期:2020-01-08 19:09 浏览次数:
除尘器的选型要考虑多种影响因素和条件,从各影响因素和条件考虑,可从如下方面进行选型:
 
  1 按粉尘的分散度和密度选型
 
  粉尘分散度对除尘器的性能影响很大,而粉尘的分散度相同,由于操作条件不同也有差异。因此,在对除尘器进行选型时,首先是要确切掌握粉尘的分散度,如粒径多在10μm以上时可选旋风除尘器;在粒径多为数微米以下,则应选用静电除尘器、布袋除尘器。而具体选择,可以根据分散度和其他要求,参考常用除尘器类型与性能表进行初步选择,然后再依照其他条件和除尘器的种类和性能介绍确定。
 
  粉尘密度对除尘器的除尘性能影响也很大。这种影响表现较为明显的是重力、惯性力和离心力除尘器。所有除尘器的一个共同点是堆积密度越小,尘粒分离捕集就越困难,粉尘的二次飞扬越严重,所以在操作与设备结构上应采取特别措施。
 
  2 按处理气体量选型
 
  处理气体量的多少是除尘器大小、类型的决定性因素,对于大气量,一定要选能处理气量大的除尘器,如果用多个处理小气量的除尘器并联使用往往是不经济的;对于较小气量,要比较用哪一种类型的除尘器较经济、较容易满足尘源点的控制和粉尘排放的环保要求。
 
  由于除尘器进入实际运行后,受操作和环境条件影响有时是不易预计的,因此,在决定设备容量时,需保证有一定的余量或预留一些可能增加设备的空间。
 
  3 按气体含尘浓度选型
 
  对重力、惯性力和旋风除尘器来说,进口含尘浓度越大,除尘效率越高,可是这样又会增加出口含尘浓度,所以不能仅根据除尘效率高就笼统地认为粉尘处理效果好。对文氏管除尘器、喷射洗涤器等湿式除尘器,以初始含尘浓度在10g/m³以下为宜;对布袋除尘器,含尘浓度愈低,除尘性能愈好。在较高初始浓度时,进行连续清灰,压力损失和排放浓度也能满足环保要求。而静电除尘器初始浓度在30g/m³以下,不加预除出尘器也可以使用。
 
  4 粉尘黏附性对选型的影响
 
  粉尘和壁面的黏附机理与粉尘的比表面积和含湿量关系很大。粉尘粒径d越小,比表面积越大,含水量越多,其黏附性也越大。
 
  在旋风除尘器中,粉尘因离心力黏附于壁面上,有发生堵塞的危险;而袋式除尘器黏附的粉尘容易使过滤袋的孔道堵塞;电除尘器则易使放电极和集尘极积尘。
 
  5 粉尘比电阻对选型的影响
 
  电除尘器的粉尘比电阻应该在104~10nΩ·cm范围之内。粉尘的比电阻随含尘气体的温度、湿度不同有很大变化,对同种粉尘,在100~200℃之间比电阻值较大;如果含尘气体加硫调质则比电阻降低。因此,在选用电除尘器时,需事先掌握粉尘的比电阻,充分考虑含尘气体温度的选择和含尘气体性质的调整。
 
  6 含尘气体温度对选型的影响
 
  干式除尘器原则上必须在含尘气体露点以上的温度下进行。在湿式除尘器中,由于水的蒸发和排放到大气后的冷凝等原因,应尽可能在低温下进行处理。在过滤筒除尘器中,直接或间接地处理含尘气体的温度应降低到滤布耐热温度以下。玻璃纤维滤布的使用温度一般在260℃以下。其它滤布则在80~200℃之间。在电除尘器中,使用温度可达400℃。要考虑粉尘的比电阻和除尘器结构热膨胀来选择处理含尘气体的温度。
 
  7 选用湿式除尘器的注意事项
 
  湿式除尘器绝大部分是用水的。若尘源设备规模较小,需要同时除去有害气体,或者需要把极其微细的炭黑、铅尘等粉尘捕集起来时,往往采用湿式除尘器。选用湿式除尘器应考虑污水处理以防止二次污染。
 
  此外,为有效地利用除尘器,应根据情况进行处理。处理含一氧化碳的烟气时,应有防止爆炸的措施,如在发生炉出口烟道的高温部位导入空气,把一氧化碳氧化成二氧化碳。
 
  除了根据以上基本因素对除尘气进行预选外,还可根据以下因素进行选型:
 
  对预选出的除尘器进行技术经济指标的分析,综合考虑设备费、运行费、使用年限、占地面积等有关因素,确定除尘器提供依据。
 
  确定除尘器必须进行环境效益的全面分析。除尘效果好,气体排放浓度低,给环境带来效益,也给生产生活带来好处,因此选择设备不可忽视。
 
  除尘器选定根据当地条件、本单位操作管理水平,并结合上述情况选定除尘器的型式。


The selection of dust remover should consider many kinds of influence factors and conditions. Considering each influence factor and condition, the selection can be made from the following aspects: 1. According to the dispersion and density of dust, the dispersion of dust has a great influence on the performance of dust remover, the dispersion degree of dust is the same, but it is different because of different operating conditions. Therefore, in the selection of dust remover, first of all, it is necessary to accurately grasp the dispersion of dust, such as more than 10 m in the size of the cyclone can be selected; in the size of more than a few microns, it should be selected electrostatic precipitator, bag filter. The concrete selection can be made according to the dispersion and other requirements, referring to the types and performance tables of common dust collectors, and then determined according to other conditions and types and performance introduction of dust collectors. The dust density also has a great influence on the dust removal performance of the dust collector. The effects of gravity, inertia force and Centrifugal Force are obvious. A common feature of all dust collectors is that the smaller the packing density, the more difficult the separation and collection of dust particles, and the more serious the secondary dust emission, so special measures should be taken in operation and equipment structure. 2 according to the type selection of treatment gas volume, the amount of treatment gas volume is the decisive factor of the size and type of the dust remover. For the air volume, we must choose the dust remover which can handle the large air volume, it is not economical to use several dedusters with small gas volume in parallel. For small gas volume, it is necessary to compare which type of deduster is more economical and easier to meet the control of dust source point and the environmental protection requirement of dust emission. It is not easy to predict the operation and environmental conditions of the dust remover when it is in actual operation. Therefore, when determining the capacity of the dust remover, it is necessary to ensure a certain margin or reserve some space which may increase the capacity of the equipment. 3 according to the type selection of gas dust concentration, for the gravity, inertia force and cyclone dust collector, the greater the dust concentration at the inlet, the higher the dust removal efficiency, but this will increase the dust concentration at the outlet, therefore, we can not generally think that the dust treatment effect is good only according to the high dust removal efficiency. For Venturi Tube and Jet Scrubber, the initial dust concentration is below 10g / m, and for bag filter, the lower the dust concentration is, the better the dust removal performance is. When the initial concentration is high, the continuous ash removal, pressure loss and emission concentration can also meet the environmental protection requirements. The initial concentration of electrostatic precipitator is less than 30g / M, no pre-precipitator can also be used. The adhesion mechanism of dust and wall surface is closely related to the specific surface area and moisture content of dust. The smaller the particle size of d, The larger the specific surface area and the more water content, the greater the adhesion. In the cyclone, the dust adhered to the wall surface due to centrifugal force, and there was the risk of blocking, while the dust adhered to the bag filter was easy to block the pore of the bag filter, and the electrostatic precipitator was easy to make the discharge electrode and dust collecting positive. 5 The influence of dust specific resistance on type selection, the dust specific resistance of electrostatic precipitator should be in the range of 104 ~ 10n cm. The specific resistance of the dust varies greatly with the temperature and humidity of the dust-containing gas. For the same kind of dust, the specific resistance is larger between 100 °C and 200 °C. Therefore, it is necessary to know the specific resistance of the dust in advance, and to consider the selection of the temperature and the adjustment of the properties of the dust-containing gas. In principle, the dry dust collector must be carried out at the temperature above the dew point of the dust-containing gas. In wet deduster, due to the evaporation of water and the condensation after discharge into the atmosphere, it should be treated at low temperature. In the cartridge filter, the temperature of directly or indirectly treating the dust-containing gas should be lower than the temperature of the heat-resistant filter cloth. The operating temperature of glass fiber filter cloth is usually below 260 °c. The other filter cloth is between 80 °C and 200 °C. In the ESP, the operating temperature can reach 400 °C. The specific resistance of the dust and the thermal expansion of the structure of the dust collector should be taken into account to select the temperature at which the gas containing dust is treated. 7 choose wet dust collector matters needing attention, wet dust collector is mostly water. If the dust source equipment is small, need to remove harmful gases, or need to be very fine carbon black, lead dust dust and other dust collection, often using wet dust collector. The choice of wet dust collector should consider sewage treatment to prevent secondary pollution. In addition, in order to effectively use the dust collector, should be handled according to the situation. When dealing with the flue gas containing carbon monoxide, there should be measures to prevent explosion, such as introducing air into the high-temperature part of the furnace outlet flue to oxidize carbon monoxide into carbon dioxide. In addition to pre-selecting the dust-removing gas according to the above basic factors, the type of dust-removing gas can also be selected according to the following factors: analyzing the technical and economic indexes of the pre-selected dust-removing devices, comprehensive consideration of equipment costs, operating costs, service life, area and other relevant factors to determine the basis for dust remover. The comprehensive analysis of environmental benefits must be carried out to determine the dust remover. Dust removal effect is good, gas emission concentration is low, to bring benefits to the environment, but also to the production and living benefits, so the choice of equipment can not be ignored. Dust Collector selected according to local conditions, the unit's level of Operation Management, and combined with the above-mentioned selection of dust collector type.

028-85358503(四川)

0571-86020907(总经理)

13881981010

成都市武侯区领事馆路8号万兴苑A座503室