100- Discussion on the use of feather leaf separators for secondary steam demisters in salty wastewater evaporators, concentrators, and crystallizers

Some industries, such as salt and alkali production enterprises, also need to evaporate, concentrate and crystallize brine during the production process, and vacuum evaporation, concentration and crystallization processes are often used to generate a large amount of secondary steam. The evaporation crystallizers of vacuum salt production enterprises often use multi-effect evaporators to evaporate and concentrate step by step. The secondary steam generated by the front-stage evaporator needs to be boosted by a steam compressor and used to provide heat energy for subsequent evaporators.

Some chemical companies will produce a large amount of brine by-product during the production process and reaction. This large amount of brine also needs to be evaporated, concentrated and crystallized. The by-product solid salt will be sold as a commodity. For example, many caprolactam manufacturers that use the oximation process will produce a large amount of anhydrous sulfate by-product during the production process. Tens of thousands of tons of anhydrous sulfate require step-by-step evaporation, concentration and crystallization processes through a multi-effect evaporation crystallizer. The secondary steam generated by the front-stage evaporator is also often used to boost the pressure through a steam compressor and reuse it as a heat medium in the subsequent evaporator.

Coastal projects and equipment often use seawater desalination devices for water supply. The large amount of salty wastewater produced by the seawater desalination process is also treated by a multi-effect evaporation crystallizer similar to the above. The secondary steam recycling process is also basically similar.

In addition to the evaporation, concentration and crystallization treatment device for saline-alkali solutions that uses MVR multi-effect evaporation crystallizers and compresses and recycles secondary steam through steam compressors, it is understood that many mixed waste acids also use compressor MVR multi-effect evaporation concentrators. For example, the alkylation units, nitration units, and sulfonation units of some fine chemical companies will produce water-containing mixed waste acids. The mixed waste acid may contain strong acids such as sulfuric acid, nitric acid, and phosphoric acid and water, and MVR evaporation and concentration method is required to recycle the mixed acid.

Of course, some friends will say that their company is also a fine chemical company that produces organic fine chemicals. The company uses falling film evaporators, rising film evaporators, and rising and falling film evaporators to evaporate and concentrate semi-finished products and finished products. All solvent vapor generated by the evaporator needs to be condensed and reused. The reason is that the semi-finished products and finished products discharged from the rising/falling film evaporator, as well as the recycled solvent vapor, are all high value-added materials and need to be recycled as much as possible.

Yes, there are many applications for evaporators, concentrators, and crystallizers. However, whether it is vacuum salt production and alkali production, ammonium sulfate recovery, seawater desalination, mixed acid reuse, or the use of rising and falling film evaporators to process high value-added fine chemicals, it is necessary to carefully select an efficient and stable gas-liquid separation demister to efficiently remove droplets carried by the secondary steam and containing salts, alkali, acids or organic matter. Otherwise, the droplets containing salt, alkali, acid and organic matter will flow to the downstream pipeline equipment with the steam, which will not only cause damage to the steam compressor, but also cause the acid, alkali and salt index of the condensate to exceed the standard and significantly increase the post-processing operating costs.

There are many companies manufacturing evaporators, concentrators, and crystallizers in East China, but most of them use traditional, simple and inefficient wire mesh secondary steam demisters. However, the secondary steam carrying the salt-containing alkali liquid droplets will precipitate and accumulate on the wire mesh during the process of passing through the inner parts of the wire mesh, forming a large hard crystal and blocking the flow channel, resulting in a higher and higher secondary steam flow rate, a lower and lower defoaming separation efficiency, a higher and higher operating pressure drop, and the evaporator heating medium temperature corresponding to the requirements is also getting higher and higher. Due to the special physical properties of the gas-liquid mixed fluid, even if the salt-alkali content in the droplets is very low, crystals will continue to precipitate and accumulate due to microscopic effects during the process of the secondary steam passing through the inner parts of the wire mesh. This is why some friends are confused. The salt content of the droplets in the secondary steam is only a few percent, which is far from reaching the saturation concentration. However, white crystals precipitate and block the screen during the process of passing through the inner parts of the screen.

An article, divided into so many sections just to win the prize, is also drunk.~~~

Some evaporator users from Hebei, Shandong, Inner Mongolia, Jiangsu and other places have called us to report that their original evaporator secondary steam demisters mostly use wire mesh demisters, which are often blocked and the defoaming effect is unstable.； Some companies also reported that their original evaporator secondary steam demister used a baffle type, but the defoaming effect was not good, and the secondary steam and condensate indicators were unqualified. We hope that we can provide them with diagnostic and technical upgrade solutions.

This post was last edited by luoli519 on 2022-11-30 18:10 Feather leaf separator, as a technical upgrade product of traditional wire mesh demister, simple baffle demister, etc., has the following technical advantages: 1. Large gas processing capacity, suitable for large-scale production ； 2. Through the design of the precise kinetic separation technology design platform system, precise quantitative separation efficiency can be achieved ； 3. The pressure drop is small, only 1/8~1/6 of the traditional wire mesh separator, which saves energy at the same time. ； 4. The operating flexibility is large and can operate efficiently within the range of 15% to 130%. ； 5. Equipment size, usually about 1/2~2/3 of traditional wire mesh separator ； 6. It has strong tolerance to crystalline particles and waxy viscosity carried in the air flow, does not block, has no spare parts, and has low operation and maintenance costs.