#scrubber wetairscrubber airpollutiom airtreatment wetscrubber

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How air pollution destroys our health

As the world around us becomes more polluted and overpopulated, factories continue to emit air pollutants into the atmosphere and half of the people does not have access to clean fuels or technologies, the levels of air pollution we breathe are becoming more dangerous — currently, 9 out of every 10 people breathe particulate pollutants, which lead to 7 million deaths each year.

Air pollution has severe health consequences - one-third of deaths from stroke, lung cancer, and heart disease are caused by the absence of air pollution control and insufficient air treatment. This is equivalent to exposure to tobacco smoke and much more serious than, for instance, the consequences of consuming excessive amounts of salt.

Air pollution is difficult to avoid no matter how rich the area you live in. Microscopic particulate pollutants can pass through the protective mechanisms of our body, penetrating deep into the respiratory and circulatory system and destroying the lungs, heart, and brain.

The absence of visible smog does not mean that there is healthy air around. All around the world, both cities and villages are exposed to toxic air pollutants that exceed the annual average recommended in the WHO air quality guidelines (the World Health Organization).

The true cost of climate change can be seen in our hospitals and felt by our lungs. The influence of dirty energy sources is so great that the transition to cleaner and more sustainable options for energy, transport and food systems will eventually pay off. When health concerns are taken into account, reducing the effects of climate change promises opportunities, not costs.

"Breathe Life", a global campaign for clean air led by the WHO, the Climate and Clean Air Coalition, and the United Nations Environment Program, calls on communities to reduce the impact of polluted air in cities, regions, and countries, providing strict air pollution control, herewith, it currently reaches about 97 million people.

The WHO, the UN environment program and the "Breathe life" campaign of the Climate and clean air coalition have developed an online tool for measuring particulate pollutant levels to help people better understand how polluted the air is where they live. 

The WHO and its partners have repeatedly held conferences on air pollution and human health in order to bring all of humanity together to meet key commitments to solve the problem. The conference attendants draw attention to this growing public health issue and provide information and tools for taking action on health risks associated with air pollution.

The Conference focuses on air treatment activities. There are available strategies for reducing emissions from energy generation, vehicle use, waste management, housing, and industrial activities. These air pollution control activities often provide other benefits, such as limiting traffic and reducing noise that contribute to improved health and well-being.

Better air quality provides benefits for all of us and everywhere. The conference calls for urgent action and agreement on a goal to reduce deaths caused by air pollution.

There are two types of pollution — outdoor air pollution and indoor pollution, which is associated with burning fuels (such as coal, firewood, or kerosene) over an open fire or in stoves in poorly ventilated areas. Both types of air pollution can aggravate each other, as air moves from rooms to the outside and vice versa.

Indoor air pollution kills 4 million people every year, mostly in Africa and Asia, where polluting fuels and technologies are used daily in homes for cooking, heating, and lighting. Women and children who spend more time indoors are most affected.

The main particulate pollutants are fine particles, i.e. a mixture of solid particles and small drops produced mainly in fuel combustion and traffic; nitrogen dioxide arising from traffic and use of gas stoves indoors; sulfur dioxide resulting from the burning of fossil fuels, and ozone at the earth's surface, formed by the reaction of sunlight with air pollutants emitted by motor vehicles. The greatest impact on people is caused by small particulate matters (often referred to as PM and used as a unit of measurement for air pollution).

Particulates with a diameter of 10 microns or less (≤ PM10) can penetrate and settle deep in the lungs, but even more dangerous to health are particles with a diameter of 2.5 microns or less (≤ PM2.5). These are the smallest particulates — 60 of these particles are equal to the thickness of a human hair.

PM2.5 can enter the lungs and circulatory system. They can increase the risk of heart and respiratory diseases, as well as lung cancer.

Polluted air has a devastating effect on children's health. Worldwide up to 14% of children aged 5-18 years suffer from asthma caused, among other things, by air pollution. Every year 543.000 children under the age of 5 die from respiratory diseases related to air pollution. Air pollution is also linked to childhood cancer. The influence of polluted air on pregnant women can lead to fetal brain development. Air pollution is also associated with cognitive impairment in both children and adults.

Ozone is one of the main causes of asthma (or its aggravation), and nitrogen dioxide and sulfur dioxide can also lead to asthma, bronchial symptoms, pneumonia, and reduced lung function. 

In addition to affecting our health, air pollutants cause long-term environmental damage, leading to climate change, which is also a significant threat to health and well-being.

The WHO and its partners, such as the United Nations Environment Program, are developing air treatment options for supporting countries. For example, the WHO is developing a set of methodologies (a set of methodologies for ensuring clean energy sources in households) to help countries implement the WHO's recommendations on household fuel combustion and develop strategies for increasing the use of clean energy sources at home.

The UN intergovernmental group of experts on climate change has warned that to limit the rate of global warming at 1.5°C, it is necessary to stop generating electricity by burning coal by 2050. Otherwise, we may see a major climate crisis in 20 years.

So how can we achieve air pollution control? For example, at present, the requirements of legislation and industry regulations on environmental protection have significantly increased. Each company that releases various particulate pollutants into the air pays for ambient air pollution if they do not exceed the established standards, in case of exceeding the standards, are subject to penalties up to the suspension of production.

Besides, it is possible to perform the air treatment of polluted air in industries. Gas air treatment devices, such as scrubbers are used for cleaning industrial gaseous waste.

A scrubber is an industrial unit used for air treatment of waste polluted air from various particulates. The scrubber is considered to be the most effective device for removing solid particles of any dispersed composition from gases. In addition to capturing dust, it can perform heat exchange and absorption processes.

A wet scrubber is a device designed for air treatment of gas from various impurities by washing the gas medium with a liquid (usually water).

The scrubber applications include:

●     Engineering;

●     Chemical industry;

●     Ferrous and non-ferrous metallurgy;

●     Oil production and petrochemical industry;

●     Coal industry;

●     Powerhouses;

●     Other areas of industry where there is a need to clean the gas from particulate pollutants.

The scrubber operating principle is based on the wet air treatment technique — the gas in the working chamber is mixed with water or other technical liquid, as a result, water droplets surround dust particulates or other contamination, after which the treated gas goes into the atmosphere, and the wastewater is drained from the working chamber. The wet air scrubber can treat the gas up to 99% due to this principle of operation.

Scrubber systems differ in the principle of operation - the size and performance of scrubbers depend on this.

Main types of scrubbers:

Centrifugal wet air scrubber;

Nozzle scrubber;

Hollow scrubber;

Venturi scrubber;

Packed bed scrubber (which, in its turn, is divided according to the principle of operation into foam and bubble).

Advantages of using scrubber systems for air treatment:

● The wet air scrubber allows you to quickly and effectively treat the environment from various particulates. The system demonstrates an uninterrupted operation for a long time.

●    The design meets safety standards. The equipment can operate even at pressures above 0.07 MPa.

●    The scrubber is multi-functional since it can be used not only for dry but also for wet air treatment. Small and large pollution, smoke, fumes, and dust are eliminated almost instantly.

●    The wet scrubber reduces the flue gas temperature and steam condensation, which is especially important for large petrochemical plants.

●    The design humidifies the air. Evaporation occurs smoothly, so temperature and pressure differences are not obvious.

● The wet air scrubber is a cost-effective device, as in the process of operation in the equipment are disposed of outgoing gases.

If you would like to make your contribution to improving air quality in order to provide air pollution control, you should choose a new type of wet scrubbers that is Multi-Vortex scrubber. Multi-Vortex wet air scrubber could apply water contaminated with dust, sand, and even small rocks to capture particulate pollutants, different types of dust and some gases from the air.  This type of scrubber is an ideal solution for ore and coal mining. Thus, it can be used in different mining, combustion and chemical processes to capture gases. Also, in some cases, the unique Multi-Vortex scrubber design allows utilizing cheaper reagents to capture the pollutant gas with more efficiency than a standard wet scrubber. If you would like to buy Multi-Vortex wet air scrubber or have some questions, please contact us at info@optromix.com

[optromix]

The application of Wet Air Scrubbing Systems in the mining industry

With the development of technology and increasing the level of air pollution, people have naturally moved towards the creation of efficient air treatment devices, one of which is a scrubber — a system of dust and gas collecting, applied in a wide range of industrial and processing enterprises.

Scrubbing systems are industrial devices designed for cleaning gaseous matters from pollutants. The application of scrubbers includes technological and chemical processes, various fields of industry. The principle of the wet scrubber operation was developed in the early to the mid-19th century.

Scrubbing systems are devices of various designs, which are used for cleaning gases with special liquids in order to clear up them and to extract one or several components, as well as drum engines for cleaning mineral resources. Such air treatment devices are widely used for capturing products of coal carbonizing process and cleaning industrial gases from dust, for moistening and cooling gases, in various chemical-technological processes.

The principle of the scrubbing system is that the scrubber picks up suspended particulate matters from the exhaust gases. After that, the gas is cleaned with water or a special solution. The process is based on the intensive mixing of gas and liquid. This cleaning technique is called wet air scrubbing. The size of air pollutants increases due to condensation of water vapor on them resulting in efficient air treatment.

For example, a hollow nozzle Venturi scrubber is designed to create a high gas flow rate. The gas enters, accelerates in the narrowing part of the scrubbing system, and then mixes with a cleaning solution at high speed. It is widely used for gas moistening and cooling, for air treatment from dust pollutants.

The wet air scrubbers treat the incoming gas-air stream with the help of water or a special deactivating solution. Based on application parameters, wet scrubbers can be divided conditionally into air treatment devices and drum engines for cleaning mineral resources.

Scrubbing systems are employed in the mining industry for catching coking pollutants. In this industry, wet air scrubbers of conical or cylindrical shape are used predominantly, resembling a drum, in the center of which there is a rotating paddle. Fossils that require cleaning procedure are placed in a scrubbing system, where they, mixing with the cleaning solution, are moved in a spiral by the paddles. Pollutants containing clay and limestone are diluted by water and then removed from the drum with it, leaving the purified material. When it comes to air pollution treatment, the purified gas is transported to the atmosphere after the air treatment process, and the liquid with sludge enters the scrubbing system's tank through the drain pipe.

The store of cleaning solution is replenished through the tank with the reserve content, and the process can be carried out again. The capacity of wet scrubbers used in the mining industry is pretty high and amounts to 200 tons, with insignificant water consumption of 3-6 m3 / ton. and with minimal time intervals.

Types of scrubbers used in the mining industry are divided into reverse-flow and straight-flow depending on the water movement relative to the material. If the direction of material flow coincides with the direction of the water flow, then the scrubber is called direct-flow, if it is not the same, then the scrubber is reverse-flow.

Thus, it is possible to clean the gas from particles of any size.

The disadvantage of wet scrubbing technology for air treatment can include the formation of a large amount of sludge. The advantages include the relatively low cost of wet scrubbing device. This method is applied in the chemical industry, foundry, leather, ceramic production, oil refining, and mining industry during working with various types of bitumen, as well as the combustion of industrial gases and waste.

Scrubbing systems are installed in large enterprises in treatment facilities. The main requirement for the wet scrubbers is the most developed surface of the contact phase. This is necessary for more complete extraction of a given component from the gas phase. The scrubbers with a movable nozzle most fully meet the conditions.

These scrubbing systems can operate at high loads in terms of gas temperature and volume, as well as concentrations of extracted components, they are characterized by high efficiency, and also have an important property - the mobility of the nozzle that eliminates the formation of suspended particles sediment and clogging the effective section of the wet scrubbing device. The high speed of the gas (3-8 m/s) makes it possible to manufacture the devices rather compact.

Modern scrubbers with a movable nozzle have different shapes and design features depending on their purpose, such as mass transfer, heat transfer, or heat-mass transfer. Herewith, the heat and mass transfer processes can take place in the device selectively at different mass transfer elements for different substances, and even during the use of absorbers differing in their characteristics.

Such properties and capabilities of scrubbers with a movable nozzle predetermined their wide distribution and application in various industries. Generally, the scrubber consists of the following parts (they may vary slightly depending on the purpose and features of operation):

air circulation and gas circuit systems;

carbonation chamber (optional);

in fact, an operational body (cleaning room);

trapping separator, (otherwise - a drop  or mist separator);

pump;

self-cleaning system and/or recycling system (optional);

outlet pipe.

In addition to washing application, scrubbing systems are used for separation (sizing) material. In order to perform the separation procedure, a conical perforated part is connected to the drum of the wet scrubber. An important feature of the wet scrubber operation is that, in fact, undesirable pollutants do not disappear anywhere during the cleaning process, but they are only “removed” from the passing polluted stream and are concentrated on a liquid solution, paste or dry powder.

It often happens that waste products from wet scrubbing systems also need to be carefully disposed of: for example, the contents of the collectors after the treatment of mercury ores should be safely buried in special mercury storage.

Nevertheless, it is impossible not to take into account the positive aspects. For example, wet air scrubbers, cleaning emissions of power plants, form synthetic gypsum of high quality as output waste that is successfully used for the manufacture of gypsum board and other building materials. And this is not the only example of rational disposal of sludge.

The following advantages should be mentioned among others:

compact size, and consequently, easy installation in the industry: the small size of the wet scrubbing devices results in less capital investment with high mobility of the structures compared with units of the same productivity, but of a different type of action;

no secondary sources of dust and air pollution: once packed in the collector, waste is easily transported without any leaks;

the ability to operate with highly saturated and high-temperature flows: no problems with condensation and temperature limitations (as, for example, in electrostatic separators or bag filters);

maximum fire and explosion safety: the presence of a liquid medium minimizes the possibility of detonation or fire in the scrubber;

universality: the ability to operate with both gaseous chemical and mechanical air pollutants of various fractions.

Such properties of dust particles as particle density, adhesion (the ability of strong adhesion), flowability, wettability, solubility of particles, electrical and electromagnetic properties of particles, ability of spontaneous combustion and formation of explosive mixtures with air have a great influence on the choice of methods and techniques of dust collection and dust suppression.

Wet scrubbing devices are characterized by high cleaning efficiency from fine dust (0.3-1.0 microns), as well as the possibility of cleaning hot and explosive gases from dust. Therefore, you should keep in mind the following during choosing means for cleaning emissions into the atmosphere:

dry mechanical methods and scrubbing devices are not effective at removing fine and sticking dust.

wet scrubbing techniques are not effective in cleaning up emissions that contain poorly cohesive and lumpy substances (for example, cement).

electric separators are not effective in removing contaminants that are poorly charged with electricity.

bag filters are not effective in cleaning the emissions from the adhesive and wetted contaminants.

wet scrubbers are not suitable for outdoor use in winter conditions.

For scrubbing of non-explosive dust, like iron ore dust, it is more beneficial to use wet scrubbers rather than dry ones. Firstly, such productions in most cases already utilize water in their manufacturing cycle.  Secondly, dry scrubbers, such as tubular cloth filters or electrofilters, usually operate at average gas flow speeds of not more than 1.5 m/s, while most wet scrubbers operate at flow speeds of 4 m/s and more.

High gas scrubbing speeds favorably affect the overall dimensions which allow wet scrubbers to be placed directly above the conveyor belt or in dusting areas.

Nowadays it is quite difficult to find an appropriate manufacturer of scrubbing systems offering high-quality scrubbing products that can be applied in numerous fields of application. Therefore, if you search the best air treatment device for the mining industry or other areas in order to improve air quality, you can buy a high-tech completely new type of wet air scrubber – a Multi-Vortex wet air scrubber produced by Optromix company.

Optromix is a fast-growing vendor of wet air scrubbers. The multi-vortex scrubber is able to remove gas emissions, dust, vapors, and other pollutants from a gas stream.  It is an innovative technology created to save water that makes it more cost-efficient and differs from other types of scrubbers.  If you have any questions or would like to purchase a multi-vortex wet air scrubber, please contact us at info@optromix.com