What is the application effect of the boiler desulfurization tower and what is the desulfurization t

Desulfurization flue gas desulfurization - the process of removing sulfur and compounds in flue gas, mainly referring to SO, SO2 in flue gas. to meet environmental requirements. Desulfurization after combustion, also known as flue gas desulfurization (flue gas

Desulfurization, referred to as FGD), in FGD technology, can be divided into the following five methods according to the type of desulfurizer: calcium method based on CaCO3 (limestone), magnesium method based on MGO, sodium method based on Na2SO3, ammonia method based on NH3, organic alkali method based on organic alkali. The commercialized technology commonly used in the world is the calcium method, accounting for more than 90%.

According to the dry and wet state of the absorbent and desulfurization products in the desulfurization process, the desulfurization technology can be divided into wet, dry and semi-dry (semi-wet) methods. The wet FGD technology is to use a solution or slurry containing an absorbent to desulfurize and treat the desulfurization products in the wet state, which has the advantages of fast desulfurization reaction speed, simple equipment and high desulfurization efficiency, but it generally has problems such as serious corrosion, high operation and maintenance costs and easy to cause secondary pollution. The desulfurization absorption and product treatment of dry FGD technology are carried out in a dry state, which has the advantages of no sewage waste acid discharge, light corrosion degree of equipment, no obvious cooling of flue gas in the purification process, high flue gas temperature after purification, conducive to chimney exhaust diffusion, and less secondary pollution, but there are problems such as low desulfurization efficiency, slow reaction speed and large equipment.

Semi-dry FGD technology refers to the flue gas desulfurization technology in which the desulfurizer is desulfurized in the dry state and regenerated in the wet state (such as the water-washed activated carbon regeneration process), or the desulfurization is desulfurized in the wet state and the desulfurization products are treated in the dry state (such as the spray drying method). In particular, the semi-dry method of desulfurization in wet state and treatment of desulfurization products in dry state has attracted widespread attention because of its advantages of fast reaction speed and high desulfurization efficiency of wet desulfurization, as well as the advantages of dry waste-free waste acid discharge and easy treatment of desulfurization products. According to the use of desulfurization products, it can be divided into two types: discarding method and ** method.

The mechanism of scale formation.

Wet. The formation of "dry" scaling is due to the slurry containing caso4, caso3, caCO3 and fly ash containing silicon, iron, aluminum and other substances, these substances have a large viscosity, when the slurry collides with the tower wall, some of them will adhere to the tower wall and settle down. At the same time, due to the high temperature of the flue gas, the evaporation of the water of the sedimentary layer is accelerated, so that the sedimentary layer gradually forms a dense structure, similar to the hard scale of cement.

The enrichment and fouling of scrubbing liquid in the "dry and wet" interface area of the absorption tower belong to this kind of scale.

"Wet and dry" scaling prevention and control "Wet and dry" scaling needs to be washed in time, and the nozzle device is generally used for the flushing structure.

Prevention and control of crystallization scale.

In order to prevent the formation of gypsum scale lake in limestone lime wet desulfurization system, it is necessary to fully and continuously limit the saturation of calcium sulfate (CaSO4) in the desulfurization medium of the circulation loop of the whole desulfurization system not to exceed the critical saturation of gypsum scaling. Forced oxidation.

For the prevention and control of soft scale, most of the desulfurization products are CaSO3·1 2H2O for the wet desulfurization system with non-forced oxidation. Due to the forced oxidation in the system, the desulfurization products CaSO3·1 2H2O have all been converted, and the system does not have the problem of soft scale.

The prevention and control of deposition and scaling makes the system run without producing the problem of deposition and scaling of equipment and pipelines, and the main methods adopted are: the internal structure of the equipment is simple, there are no easily obstructive parts: the pipeline flow rate is selected reasonably, and attention is paid to the smooth flow of pipe fittings and elbows

The bottom of the oxidation tank can be conical bucket structure, which is not easy to form a stacking dead zone, controls the stirring intensity of the agitator, and starts running as soon as the system is started.

<> desulfurization tower is a tower equipment for desulfurization treatment of industrial waste gas. The desulfurization tower was originally the most widely used in granite masonry, which uses the principle of water film desulfurization and dust removal, also known as granite water film desulfurization dust collector, or granite water film desulfurization dust collector.

The scrubber is a device used to purify flue gas. It works by absorbing and decomposing sulfides in flue gases, such as sulfur dioxide, thereby reducing pollution to the environment. Absorbents, such as lime, are added to the scrubbers to convert the sulfides into harmless substances, such as sulfates.

This is important to protect air quality and reduce adverse effects on human health.

It has the characteristics of easy maintenance, and can achieve the effect of dust removal and desulfurization (denitrification) at the same time by formulating different dust collectors. With the development of FRP technology, the desulfurization tower was gradually changed to be made of FRP. Compared with granite desulfurization towers, FRP desulfurization towers have low cost, easy processing, stainless steel and light weight, so they have become the development trend of desulfurization towers in the future.

In addition, 316L stainless steel has three advantages: corrosion resistance, high temperature resistance and wear resistance, and it is also one of the important trends in the development of desulfurization towers. After years of improvement, it has developed into various types of desulfurization towers such as venturi type, swirl plate type, cyclone column type, float type, sieve plate type, pneumatic emulsification type, etc., and the equipment technology is becoming more and more mature, each with its own advantages and disadvantages, and enterprises can choose different types according to their own needs.

The desulfurization tower is a kind of tower equipment for desulfurization treatment of industrial waste gas. This kind of equipment is easy to maintain, and can achieve the effect of dust removal and desulfurization (denitrification) at the same time through different dust collectors. The desulfurization tower was first applied to granite masonry, because it uses the principle of water film desulfurization and dust removal, so it is also known as granite water film desulfurization dust collector and granite water film desulfurization dust collector.

With the development of FRP technology, the desulfurization tower was gradually changed to FRP manufacturing. The desulfurization tower made of FRP is low cost, simple to process, light in weight, and stainless and rotten. At the same time, 316L stainless steel has the three advantages of corrosion resistance, high temperature resistance and wear resistance, and is also one of the important trends in the development of desulfurization towers.

Generally, the large-scale desulfurization device for flue gas desulfurization of the desulfurization tower is called the "desulfurization tower", while the small desulfurization and dust removal device used for the flue gas desulfurization of coal-fired industrial boilers and kilns is mostly called the "desulfurization dust collector". They have certain requirements for desulfurization, namely:

There is a large contact area and a certain contact time between gas and liquid;

The gas-liquid disturbance is strong, the absorption resistance is small, and the absorption efficiency of SO2 is high.

The pressure drop when the air flow passes through should be small;

Stable operation, suitable operational flexibility, etc.

There are many types of scrubbers:

Marsulex Corporation of the United States Circular Sprinkler Tower + Sprinkler Device.

Fisia Babcock GmbH in Germany Circular Spray Air Tower + Structural Optimization.

Altom Corporation of the United States Circular Spray Empty Tower + Structural Optimization.

American Bawei Company Circular Spray Empty Tower + Tray.

German Bichuff Company Circular spray empty tower + slurry stratification, pulse suspension system.

Japan's Mitsubishi Liquid column tower + square tower.

Kawasaki Corporation of Japan Circular spray tower + internal partition, external mist eliminator.

Japan Hitachi Circular Spray Empty Tower + Structural Optimization.

Japan's Ishikawajima Company Circular Spray Empty Tower + Structural Optimization.

Chiyoda Corporation of Japan Round bubbling tower (CT-121 technology).

DUCON Circular Spray Tower + Venturi Grille.

Knoll GmbH Dual-circuit technology.

Italian AEE company Circular spray empty tower + structural optimization.

Italian company IDRECO Circular spray empty tower + structural optimization.

Regardless of how the scrubber changes, the following principles need to be followed.

1. The contact area between the flue gas and the limestone slurry is large, and the contact time is relatively long;

2. The disturbance between the flue gas and the limestone slurry is violent, the absorption resistance is small, and the absorption efficiency is high;

3. The absorption tower is stable in operation, and has different degrees of bearing capacity to load changes;

4. The pressure drop of flue gas through the absorption tower is small;

5. The structure of the absorption tower tends to be simplified, the manufacturing and maintenance are convenient, and the cost is continuously reduced;

6. For different situations, it has the ability of anti-corrosion and anti-clogging.

The desulfurization tower for natural gas purification is divided into dry and wet process.

The dry method is divided into two types: physical adsorption method and direct oxidation method.

There are physical absorption methods and chemical absorption methods for wet processes.

The spray tower is a continuous acid mist exhaust gas introduced into the purification tower by the air duct, through the packing layer, the exhaust gas and sodium hydroxide.

The absorption liquid is fully contacted, absorbed and neutralized by gas-liquid two phases.

After the acid mist exhaust gas is purified, it is dehydrated and defogged by the defogging plate and discharged into the atmosphere by the fan.

The absorbent liquid is pressurized by the water pump at the bottom of the tower and sprayed down at the top of the tower, and finally flows back to the bottom of the tower for recycling. The purified acid mist exhaust gas meets the emission requirements of local emission standards and is lower than the national emission standards.

First, the hot flue gas enters the pre-scrubber and comes into contact with the saturated ammonium sulfate solution, where the flue gas is cooled and at the same time, ammonium sulfate crystals are precipitated due to the evaporation of water in the saturated ammonium sulfate solution.

The flue gas, which has been cooled, enters the SO2 absorption tower through the mist eliminator. In the absorption tower, ammonia is mixed with water to form an ammonia solution. The SO2 in the flue gas is absorbed here and reacts with ammonia to form ammonium sulfate.

Finally, after desulfurization, the flue gas is discharged into the atmosphere through a 120-meter-high chimney.

The ammonium sulphate solution is sent to the pre-scrubber for recycling. The ammonium sulphate slurry in the pre-scrubber enters the dewatering system. It is first dewatered by a water conservancy cyclone, and then ammonium sulfate filter cake is obtained by centrifuge.

The clear liquid from the cyclone and centrifuge** is returned to the pre-washer for recycling. The ammonium sulphate filter cake is sent to the pelletizing system to obtain a high-value granular ammonium sulphate fertilizer, which is stored in a dome storage silo with a capacity of 50,000 tons of ammonium sulphate before being transported by train or truck.

Ozone simultaneous desulfurization and denitrification is mainly to use the strong oxidation of ozone to oxidize NO into nitrogen oxides, and then absorb nitrogen oxides and sulfur dioxide in the scrubber at the same time and convert them into water-soluble substances to achieve the purpose of removal.

Excuse me, what is the function of the scrubber?

The working principle of desulfurization of the scrubber:

It is the use of desulfurization absorbent, through chemical reaction, to achieve the effect of desulfurization. The desulfurizer has surface activity, catalytic oxidation, promotes the direct reaction of sulfur dioxide SO2, accelerates the dissolution of calcium carbonate CaCO3, promotes the rapid oxidation of calcium sulfite CaSO3 to calcium sulfate CaSO4, strengthens the precipitation of calcium sulfate CaSO4, reduces the liquid-gas ratio, reduces the calcium-sulfur ratio, and reduces the evaporation of water.

<> desulfurization tower is a tower equipment for desulfurization treatment of industrial waste gas.

The desulfurization tower was originally the most widely used in granite masonry, which uses the principle of water film desulfurization and dust removal, also known as granite water film desulfurization dust collector, or Ma Hand Stone water film desulfurization dust collector.

Advantages of scrubbers:

Yiwei talks about shirt protection, and can achieve the effect of dust removal and desulfurization (denitrification) at the same time by formulating different dust removers. Now with the development of FRP technology, the desulfurization tower is gradually changed to be made of FRP.

Disadvantages of scrubbers:

For the large scrubbers in the power plant, most of them are vertical and high-rise structures, basically reaching more than 50m. The flue gas scrubber not only bears pressure, temperature and gravity loads, but also dynamic loads such as wind loads and ** loads. If the magnitude, direction and even the application point of the dynamic load change with time, the dynamic load causes the structure to accelerate, cause resonance phenomenon, and is prone to vibration accidents.