瀝青尾氣凈化塔及裝置Asphalt exhaust gas purification tower and system
瀝青煙氣具有以下特點：瀝青煙氣組分極為復(fù)雜，既有瀝青揮發(fā)組分凝結(jié)成的固體和液體微粒，又有蒸氣狀態(tài)的有機物，部分有機物是高分子聚合物,對環(huán)境造成嚴重污染。煙氣中含有多種有機物，包括碳環(huán)烴、環(huán)烴衍生物及其它化合物，有不少對人身健康有危害作用，瀝青煙含有苯并芘、苯并蒽、咔唑等多種多環(huán)芳烴類物質(zhì)，且大多是致癌和強致癌物質(zhì)，粒徑多在0．1～1．0μm之間，最小的僅0．01μm，最大的約為10．0μm，尤其是以3，4-苯并芘為代表的多種致癌物質(zhì)。其危害人體健康的主要途徑是附著在8 um以下的飄塵上，通過呼吸道被吸人體內(nèi)。吸入瀝青煙能引起頭痛、眩暈、惡心、嘔吐、肝臟腫大和白血球增高等癥狀。接觸瀝青煙，可引起急性光敏性皮炎、角膜炎，并使皮膚產(chǎn)生明顯的色素沉著，形成黑頭粉刺、毛囊炎和血管腫瘤等。苯并(a)蓖等化合物還是致癌物質(zhì)。
此外易粘附, 在一定溫度之上易燃爆。在瀝青煙氣的收集、輸送及消煙過程中, 極易粘著管道及設(shè)備表面形成液態(tài)至固態(tài)瀝青。固結(jié)后的瀝青很難清除掉, 往往造成管道堵塞、設(shè)備破壞, 使系統(tǒng)無法正常運行。
因此，對瀝青煙氣進行合理有效凈化治理，使排放滿足大氣環(huán)境標(biāo)準(zhǔn)，又能保證裝置正常生產(chǎn)運行是非常必要的。針對瀝青煙氣的特點，采用洗油吸收的方法和高效凈化工藝，來處理瀝青煙氣，改善環(huán)境，使得凈化后煙氣滿足《大氣污染物綜合排放標(biāo)準(zhǔn)》。工藝選擇的主要設(shè)計原則為：
1） 采用先進、成熟、可靠的凈化工藝和成套技術(shù)，凈化效率高、設(shè)備選材合理、裝置能夠長周期穩(wěn)定運行。
2） 吸收劑的來源可靠。
3） 凈化系統(tǒng)運行成本低。
4） 副產(chǎn)品的處置途徑可靠。
5） 保證尾氣凈化系統(tǒng)的狀況不影響主體系統(tǒng)的正常運行。
The characteristics of asphalt fumes are as follows: The composition of asphalt fumes is extremely complex. There are both solid and liquid particles formed by the volatilization of asphalt components, as well as organic substances in vapor state. Some of these organic substances are high-molecular polymers, causing severe pollution to the environment. The fumes contain various organic compounds, including cycloalkanes, cycloalkane derivatives, and other compounds. Many of them are harmful to human health. Asphalt fumes contain various polycyclic aromatic hydrocarbons such as benzo[a]pyrene, benzo[a]anthracene, and carbazole, and most of them are carcinogenic and highly carcinogenic substances. The particle size is mostly between 0.1 and 1.0 μm, with the smallest being 0.01 μm and the largest being approximately 10.0 μm. Especially, various carcinogenic substances represented by 3,4-benzopyrene are included. The main way for it to harm human health is to adhere to the dust particles of 8 μm or less and be absorbed into the body through the respiratory tract. Inhalation of asphalt fumes can cause symptoms such as headache, dizziness, nausea, vomiting, liver enlargement, and increased white blood cells. Contact with asphalt fumes can cause acute photosensitive dermatitis, keratitis, and significant pigmentation on the skin, resulting in blackheads, folliculitis, and vascular tumors. Compounds such as benzo(a)pyrene are also carcinogenic substances.
In addition, it is prone to adhesion and is flammable and explosive at certain temperatures. During the collection, transportation, and smoke elimination process of asphalt fumes, it is easy to adhere to the surfaces of pipelines and equipment, forming liquid to solid asphalt. The consolidated asphalt is difficult to remove and often causes pipeline blockage and equipment damage, making the system unable to operate normally.
Therefore, it is very necessary to conduct reasonable and effective purification treatment of asphalt fumes to ensure that the emissions meet the atmospheric environmental standards and also guarantee the normal operation of the equipment. In view of the characteristics of asphalt fumes, the methods of oil absorption and efficient purification processes are adopted to treat asphalt fumes, improve the environment, and make the purified fumes meet the "Integrated Emission Standards for Air Pollutants". The main design principles for the process selection are:
1) Adopt advanced, mature, and reliable purification processes and complete technologies, with high purification efficiency, reasonable equipment selection, and the device being able to operate stably for a long period.
2) The source of the absorbent is reliable.
3) The operation cost of the purification system is low.
4) The disposal route of the by-products is reliable.
5) Ensure that the condition of the tail gas purification system does not affect the normal operation of the main system.
