Classification and analysis of six kinds of wet desulfurization technology

2016-07-19 15:42:04

In recent years, the waste gas treatment has aroused the concern of all circles. This article will introduce six kinds of wet desulfurization technology, the content is as follows:

Despite a variety of wet flue gas desulfurization technology in the world, but the principles are all much of a muchness. The difference is mainly reflected in the absorption tower has a characteristic each, while other systems such as flue gas system of sorbent preparation system, gypsum dewatering system and waste water treatment system is almost no difference.
Wet desulfurization technology can according to the absorption tower of a different classification, can be roughly divided into the following categories: single loop spray tower, double loop spray tower, than convincing Love waves absorption tower, a liquid column injection, bubbling tower, packed tower.

1.1 single loop spray tower
Single loop spray tower is the use of the world's most extensive absorption tower, about more than 80% of the wet flue gas desulfurization using single loop spray tower, the world most professional company with wet flue gas desulfurization technology using the absorption tower, the company mainly for Alstom, IHI, Hitachi, B & W, Steinm ller, AE, abb, Ge, MASULEX etc..
Single loop spray tower is generally cylindrical tower, at the lower part of the tower for the slurry pool, oxidation zone is located in the slurry tank at the lower part, the top of slurry pond, tower in the lower part of the is flue gas inlet, in the upper part of the tower is the spray layer, between the spray layer and a flue gas inlet, a central tower for absorption region, spray layer, near the demister, tower and a flue gas outlet is lateral to the top of the tower.
Single loop spray tower is simple in structure, reasonable in structure, no filler or grating in the tower, reducing the scale and blocking phenomenon, and is also the most economical absorption tower in all absorption tower.

1.2 double loop spray tower
Double loop spray tower Research-Cottrell of the United States and Germany, the company's patented technology - kurtz. Tower structure and single loop spray tower is similar, the difference is in the absorption tower in the loop loop is divided into the lower cycle and the two loop, using double loop circuit operation.
Lower pH value of the lower loop circuit is conducive to the oxidation reaction and gypsum formation, the upper circulating circuit pH value is high, it is conducive to the absorption reaction, can get a higher desulfurization efficiency. Because the double loop circuit is adopted, the reaction in the two loops can be carried out under different pH values, which is beneficial to the improvement of the SO2 removal efficiency and the reduction of the absorbent consumption. Another notable feature of the process is due to the HCl in the flue gas almost in the circulation loop completely removed, so you can will have limit corrosion of chloride in the absorption tower of a very small area, reduce the corrosion of other regions of the tower absorption.

1.3 than convincing Love waves absorption tower
Than convincing Love waves absorption tower in fact is a single loop spray tower, the reason for the list it separately as a category, is because it is unique, and the conventional single loop spray tower is quite different.
Its main characteristic is that it is the slurry pool is divided into two, upper oxidized zone is running at a low pH environment provides the best conditions for oxidation, the lower part of the newly added absorber area and higher pH values, is conducive to the absorption reaction. Than convincing Love waves absorption tower with double loop spray tower points for the different pH values of the regional advantages, but the tower structure than double loop spray tower is simple, just a loop.
Than convincing Love waves absorption tower also a characteristic is its pulse suspension system, does not need the mixer, slurry mixing by pulse pump, long-term shutdown after can be started barrier free.

1.4 liquid injection tower
Liquid injection tower is a Mitsubishi Co's patented technology, the three kinds of absorption towers are all belong to the spray tower, and the liquid column is completely different from the spray tower.
Spray tower is the absorber (slurry) from spray down, spray layer is provided with a plurality of layers, and filling tower is from bottom to top injection, forming a tree of injection, liquid injection in the rise and fall of repeated exposure to tobacco smoke. Complete absorption reaction, spraying layer is arranged in single layer.
Liquid filling tower structure than a spray tower is more simple, especially in spray (spray) layer, spray tower spray layer is a multilayer, distribution of the nozzle and the nozzle spray angle have strict requirements, and liquid spray tower of spray layer without strict requirements, technology is easy to realize.

1.5 packing tower
Packed tower is mainly used in the early wet desulfurization equipment, because of its scaling and clogging problems difficult to solve, the new desulfurization device has been rarely used in packed tower.

1.6 bubble column
Bubble column is Chiyoda chemical construction development development of wet FGD technology, introduced above five mechanism of desulfurization absorption tower is consistent, is through the flue gas and slurry droplets and droplet cocurrent or countercurrent contact reaction, SO2 removal in flue gas, and the drum bubble tower desulfurization machine is completely different, it is the flue gas is connected directly to the slurry, through the flue gas in the slurry bulging bubbles and slurry of contact reaction.
In the absorption tower structure, bubbling tower and spray tower is the most significant difference is bubbling tower is not provided with a spray layer, so system without circulating slurry pump, however, bubble column into the slurry flue gas pipe has many roots, internal parts, more complex structure, system resistance.