AF泡沫泵除霧器板片形狀和特點(diǎn)
  濕法FGD系統(tǒng)中的除霧器板片常用高分子材料(聚丙烯、玻璃鋼)或不銹鋼制作，除霧器板片種類繁多，如圖3-20所示，按幾何形狀可分為折線型和流線型，按結(jié)構(gòu)等征可分為2通道板片和3通道板片:煙氣流向改變90°為一個(gè)折拐，也稱為一個(gè)通道。
    各類結(jié)構(gòu)的除霧器板片各具特點(diǎn)。圖3-20(a)形板片結(jié)構(gòu)簡(jiǎn)單，易沖洗，適用于各種材質(zhì);圖3-20(b)、(c)形板片臨界流速較高，易請(qǐng)洗，目前在大型脫硫設(shè)備中使用較多；圖3-20(d)形板片除霧效率高，但清洗困難，使用場(chǎng)合受到限制。
  三、除霧器布置方向及優(yōu)缺點(diǎn)
  除霧器的布置方向是根據(jù)煙氣流過(guò)除霧器截面的方向來(lái)定義的，分為垂直布置和水平布置兩種。對(duì)于垂直除霧器，除霧器的組件水平放置，煙氣垂直向上流過(guò)除霧器組件，如圖3-21所示。水平流除霧器的組件是垂直布置，煙氣流沿水平方向通過(guò)除霧器，如順流格柵填料吸收塔(見(jiàn)圖3-9)和噴射鼓泡反應(yīng)器(見(jiàn)圖3-10)的除霧器。
    除霧器的這兩種布置方式都有優(yōu)缺點(diǎn)，從圖3-21可以看到，在水平流除霧器中，從煙氣中去除的液滴沿板片凹槽、垂直于煙氣流向向下流，而垂直流除霧器捕獲的液滴是沿除霧器板片較寬的一邊逆著流方向向下流。因此，水平流除霧器降低了氣流剝離板片上液膜形成二次帶水的可能性。而垂直流除霧當(dāng)情況正好用反，特別當(dāng)離開(kāi)板片的液滴較小時(shí)，即使煙氣流速比較低，也易被再次霧化進(jìn)入用煙氣中。因此，在較高煙氣流速下，水平流除霧器除霧效果較垂直除霧器更好。AF泡沫泵

Shape and characteristics of AF foam pump demister plate

In wet FGD system, mist eliminator plates are usually made of polymer materials (polypropylene, fiberglass reinforced plastics) or stainless steel. There are many kinds of mist eliminator plates. As shown in Figure 3-20, mist eliminator plates can be divided into two-channel plates and three-channel plates according to their geometrical shapes and structural characteristics. The change of 90 degrees of smoke flow direction is also called a bend. For a channel.

The defogger plates of various structures have their own characteristics. Figure 3-20 (a) plate is simple in structure and easy to wash, which is suitable for all kinds of materials; Figure 3-20 (b), (c) plate has high critical flow rate and easy to wash, and is widely used in large-scale desulfurization equipment; Figure 3-20 (d) plate has high defogging efficiency, but its cleaning is difficult, and its use is limited.

3. Distribution direction and advantages and disadvantages of demister

The layout direction of mist eliminator is defined according to the direction of smoke passing through the cross section of mist eliminator, which is divided into vertical layout and horizontal layout. For a vertical demister, the components of the demister are placed horizontally, and the smoke flows vertically upward through the demister components, as shown in Fig. 3-21. The components of the horizontal flow demister are arranged vertically, and the smoke flow passes through the demister along the horizontal direction, such as the demister of the downstream grid packing absorption tower (see Figure 3-9) and the jet bubbling reactor (see Figure 3-10).

The advantages and disadvantages of the two layout methods of demister can be seen from Figure 3-21. In horizontal flow demister, droplets removed from flue gas flow downward along the plate groove, perpendicular to the smoke flow, while droplets captured by vertical flow demister flow downward along the wider side of the demister plate. Therefore, the horizontal flow demister reduces the possibility of secondary water entrainment from the liquid film on the stripping plate. Vertical flow defogging is reversible, especially when the droplets leaving the plate are small, even if the smoke velocity is relatively low, it is easy to be re-atomized into the used smoke. Therefore, the horizontal defogger has better defogging effect than the vertical defogger at higher flue gas velocity.