車間除塵設(shè)備的凈化工藝流程解析

Analysis of purification process of dedusting equipment in workshop

(1)吸收裝置：吸收裝置基本上可以分為三***類型，即填料塔、板式塔、噴淋塔(包括文丘里管與噴射泵)。另外還有一些***殊的塔型如湍球塔，見(jiàn)圖2-19.填料塔是在塔內(nèi)裝有一定高度的填料層，液體從塔***沿填料表面呈薄膜狀向下流動(dòng)，氣體則呈連續(xù)相由下向上同液膜逆流接觸，發(fā)生傳質(zhì)過(guò)程.板式塔是在塔內(nèi)裝有一定數(shù)量的塔板，氣體以鼓泡或噴射形式穿過(guò)板上液層時(shí)，進(jìn)行氣液接觸.噴淋塔是在塔內(nèi)氣液直接接觸。

(1) absorption device: the absorption device can be basically divided into three types, namely, packing tower, plate tower, spray tower (including venturi tube and jet pump). In addition, there are some special tower types, such as turbulent sphere tower, as shown in Figure 2-19. The packed tower is equipped with a certain height of packing layer. The liquid flows down the packing surface in a film shape from the top of the tower, while the gas is in a continuous phase and contacts with the liquid film in reverse flow from the bottom to the top. Mass transfer occurs in the plate tower. A certain number of plates are installed in the tower, when the gas passes through the liquid layer on the plate in the form of bubbling or spraying The spray tower is in direct contact with the gas and liquid in the tower.

(2)除塵處理：在吸收之前，若能專門設(shè)置高效的除塵器(如電除塵器等)，那是***理想的，然而也可能是不太經(jīng)濟(jì)的.若能在吸收時(shí)考慮在清除氣態(tài)污染物的過(guò)程中，一同清除煙氣，那是較為理想的.如在吸收塔前增設(shè)預(yù)洗滌塔;或只用一個(gè)塔，下段為預(yù)洗段、上段為吸收段;或研究出既能除塵又能吸收氣體的濕式洗滌器，不過(guò)這二者的設(shè)計(jì)要求是不***一致的，應(yīng)予充分注意。

(2) dedusting treatment: before absorption, it is the most ideal if a high-efficiency deduster (such as electrostatic precipitator) can be specially set up, but it may not be economical. It is more ideal if the flue gas can be removed together in the process of removing gaseous pollutants during absorption. For example, a pre washing tower is added in front of the absorption tower, or only one tower is used, the lower section is the pre washing section, and the upper section is the suction section The design requirements of the wet scrubber, which can not only remove dust but also absorb gas, should be paid more attention.

(3)預(yù)冷卻處理：吸收操作希望在較低溫度下進(jìn)行，但有的廢氣溫度較高，這就豁要在吸收之前進(jìn)行煙氣的冷卻，其方法可采用換熱器，但設(shè)備龐***;也可用水直噴人煙道增濕降溫，但易形成酸霧腐蝕設(shè)備或阻塞管道;目前使用較廣的是用預(yù)洗滌塔或預(yù)洗滌段，效果較***。

(3) pre cooling treatment: the absorption operation is expected to be carried out at a lower temperature, but some exhaust gases have a higher temperature, so it is necessary to cool the flue gas before absorption. The method can be heat exchanger, but the equipment is huge; it can also be used to humidify and cool the flue gas by direct injection of water, but it is easy to form acid mist to corrode the equipment or block the pipeline; at present, the pre washing tower or pre washing section is widely used, with better effect OK.

(4)凈化氣體的熱處理：在冷卻增濕處理***量煙氣和某些不利的氣象條件下，將發(fā)生“白煙’，白煙在沒(méi)有充分上升、擴(kuò)散之前就已回到地面，會(huì)產(chǎn)生較高濃度的污染.防止白煙的措施之一是設(shè)置尾部撇燒護(hù)，嫩燒天然氣或重油，使少量燃?xì)饣烊藘艋瘹庵?，這種效果較***。

(4) heat treatment of purified gas: under the condition of cooling and humidifying a large number of flue gas and some unfavorable meteorological conditions, "white smoke" will occur, and white smoke will return to the ground before fully rising and diffusing, which will produce high concentration of pollution. One of the measures to prevent white smoke is to install tail skimming protection, tender burning of natural gas or heavy oil, so that a small amount of gas is mixed with purified gas, which has a better effect OK.

(5)廢液處理：吸收了氣態(tài)污染物的富液如果丟棄，不僅浪費(fèi)了資源，而且造成了二次污染、所以，必須經(jīng)濟(jì)合理地對(duì)廢液進(jìn)行處理和利用如吸收了廢氣中so1的堿液，可以用加熱和減壓再生的方法，恢復(fù)吸收劑的能力，而同時(shí)又排放出硫酸副產(chǎn)品;也可以用濃縮富液和結(jié)晶分離的方法，獲得亞硫酸鈉副產(chǎn)品，這些都達(dá)到了廢物資源化的目的。

(5) waste liquid treatment: if the rich liquid absorbed gaseous pollutants is discarded, it will not only waste resources, but also cause secondary pollution. Therefore, it must be treated and utilized economically and reasonably. For example, if the alkali liquid absorbed SO1 in the waste gas can be regenerated by heating and reducing pressure to restore the capacity of the absorbent, and at the same time, the byproduct of sulfuric acid can be discharged; it can also be used to concentrate the rich liquid and The method of crystal separation and the by-product of sodium sulfite have achieved the goal of waste recycling.