AF泡沫泵煙氣換熱器
  一、概述
  1.煙氣換熱器作用
  煙氣換熱器作用是利用原煙氣將脫硫后的凈煙氣進(jìn)行加熱，使排煙溫度達(dá)到露點(diǎn)之上，減輕對(duì)凈煙道和煙囪的腐蝕，提高污染物的擴(kuò)散程度。同時(shí)降低進(jìn)入吸收塔的煙氣溫度，降低塔內(nèi)對(duì)防腐的工藝技術(shù)要求。
  濕法脫硫工藝系統(tǒng)中，自鍋爐引風(fēng)機(jī)來(lái)的煙氣(溫度一般為120~150°C)在進(jìn)入吸收塔中洗滌脫硫前，首先經(jīng)過(guò)吸收塔進(jìn)口煙道上的換熱器，從換熱器出來(lái)的煙氣溫度降至90~100°C左右，然后進(jìn)入吸收塔先滌脫硫，其目的是:①為了保護(hù)吸收塔中的元件及防腐層②使吸收塔內(nèi)煙氣達(dá)到有利于吸收SO2的溫度:③減少吸收塔中蒸發(fā)水量，降低水耗。吸收塔出口洗滌脫硫后的煙氣被冷卻到45~55°C為了保證煙氣能充分?jǐn)U散，降低排煙的可見(jiàn)度，避免煙囪降落液滴，同時(shí)避免凈煙氣在排放時(shí)結(jié)露造成腐蝕，需要將煙氣加熱到75~80°C。
  煙氣換熱器通常有蓄熱式和非蓄熱式兩種形式。蓄熱式煙氣換熱器是通過(guò)熱載體或載熱介質(zhì)將熱地氣的熱量傳遞給冷煙氣，主要有回轉(zhuǎn)式氣-氣換熱器(GGH)、水一氣換熱器（MGGH）和蒸發(fā)管式換熱器（簡(jiǎn)稱(chēng)熱管)非蓄熱式煙氣換熱器是通過(guò)蒸汽或天然氣燃燒等加熱冷煙氣，這種加熱方式初投資較小，但功耗高、運(yùn)行費(fèi)用較大，這里主要對(duì)蓄熱式的換熱器進(jìn)行介紹。AF泡沫泵

Flue gas heat exchanger

I. overview

1. Function of Flue Gas Heat Exchanger

The function of flue gas heat exchanger is to use the original flue gas to heat the net flue gas after desulfurization, so that the exhaust gas temperature can reach above dew point, reduce the corrosion of the net flue and chimney, and improve the diffusion degree of pollutants. At the same time, the flue gas temperature entering the absorption tower is lowered, and the technical requirements for anticorrosion in the tower are reduced.

In the wet desulfurization process system, the flue gas from the boiler induced draft fan (the temperature is generally 120-150 degrees C) passes through the heat exchanger at the inlet flue of the absorption tower before it is washed and desulfurized. The temperature of the flue gas from the heat exchanger drops to about 90-100 degrees C, and then it is washed and desulfurized before entering the absorption tower. Its purpose is: (1) to protect the components and anticorrosive layer in the absorption tower; (2) to make the absorption tower inside. The flue gas reaches the temperature favorable for SO2 absorption. 3. Reduce the evaporation water quantity and water consumption in the absorption tower. The flue gas after scrubbing and desulfurization at the outlet of absorption tower is cooled to 45-55 degrees C. In order to ensure that the flue gas can fully diffuse, reduce the visibility of exhaust smoke, avoid droplets falling from chimneys, and avoid the corrosion caused by condensation of net flue gas during discharge, it is necessary to heat the flue gas to 75-80 degrees C.

There are two types of flue gas heat exchangers: regenerative and non-regenerative. Regenerative flue gas heat exchanger transfers heat from hot ground gas to cold flue gas through heat carrier or heat carrier. The main types of heat exchanger are rotary gas-gas heat exchanger (GGH), water-gas heat exchanger (MGGH) and evaporative tube heat exchanger (heat pipe) non-regenerative flue gas heat exchanger, which heates cold flue gas through steam or natural gas combustion. This heating method has low initial investment, but high power consumption and operation. The cost is large. Here, the regenerative heat exchanger is mainly introduced.