Owners of private houses that are heated using solid fuel boilers regularly face the same problem - coal dust accumulates in fuel storage areas. If you do not clean the room, then over time a lot of waste is collected, so many begin to wonder: is it possible and how to heat the house with coal dust. Experienced stokers say that this is quite possible. Moreover, there are two options for the use of dusty waste.
The easy way and its disadvantages
A simple way to heat a house using coal dust involves loading it into an already melted boiler. To do this, dry firewood is placed in the firebox, kindled when the combustion process reaches a certain stage, coal of a large fraction is loaded. The fuel should burn well., otherwise, after loading the dust, the fire will simply go out. If you add coal suspension at the final stage of this process, then it will smolder for a long time, while releasing a sufficient amount of heat.
What are the disadvantages of the described method? One of them has already been mentioned - if dust is loaded into the boiler untimely or in too much quantity, the combustion will stop, and when trying to re-ignite the fire, you may encounter certain difficulties. At the same time, there is no formula for the exact calculation of the required amount of dust. Here you have to focus on the internal volume of the furnace, the maximum traction force in the boiler and many other factors. That is, it is possible to determine the desired figure only by experience.
The second drawback is more serious. The fact is that coal dust itself is highly explosive. In a settled state, it does not pose a threat, but if the concentration of suspended matter in the air reaches certain values, an explosion may occur with a high degree of probability. Its destructive power will not be so great, but the main danger in such situations comes from the subsequent fire. Owners who are seriously thinking about how to heat a house with coal dust should always remember this property of crushed fuel.
Preparation of a special mixture
It was an attempt to eliminate the fire hazard arising from the use of dry coal dust that led to the emergence of a second method of heating with its help. In this case first, a special mixture is prepared, somewhat reminiscent of fuel briquettes . There is nothing complicated in this technology and, in principle, everyone can master it at home.
So, to prepare the fuel mixture, they take the same amount of coal dust and small sawdust, combine them, add water and mix until a homogeneous mass is obtained. The main secret here is to correctly determine the required amount of water, which, when added, is guided by the consistency of the mixture. It should resemble too thick plaster, be slightly damp and seize in dense lumps during mixing.
How to heat a house with coal dust, or rather a mixture based on it? To begin with, firewood is loaded into the boiler, completely filling the volume of the furnace. For this purpose it is desirable to select wood with a dense structure, which, when burned, gives good coals, and does not crumble into fine ash. After the firewood flares up, wait 10-15 minutes for a suitable fire to be established in the internal volume of the boiler. temperature regime. Next, the burning logs are carefully leveled with a poker and the prepared mixture is spread on top of the slide.
Since the coal-sawdust mixture has a high moisture content, immediately after loading it, the temperature in the boiler will drop sharply. That's why it is necessary to open the full draft, and if possible, direct a strong air flow into the lower blower. To do this, you can use a regular small fan. It is turned off as soon as the combustion process is restored, and the temperature slowly rises. At the same time cover the air duct damper.
A mixture of coal dust and sawdust will not so much burn as actively smolder. This process can last up to 5 hours - it all depends on the mode of air exchange in the boiler. Experience shows that the thermal energy that is released during the complete combustion of 15 liters of the mixture is enough to heat a house with an area of 100-120 square meters. meters for 10-12 hours. Thus, the procedure described above will have to be repeated twice a day.
So, if you are seriously thinking about how to heat a house with coal dust, then you have two options. In the first case, you simply pour dust into the boiler, where coarse coal is already burning. At the same time, it is very important to determine the optimal amount of pulverized fuels, and also to prevent the transition of dust into a suspended state, since this is fraught with its explosion with all the consequences. The second method is more complicated - the dust is mixed with sawdust and, gradually pouring in water, the desired consistency of the mixture is achieved, which is then loaded into the boiler over burning firewood. This method requires preliminary preparation, but it is safer and more effective.
organic dust In most cases, they do not cause pneumoconiosis on their own. The cases of coniosis described in the literature, caused by certain organic dusts, with a more thorough analysis of the symptomatology, often turn out not to be coniosis, but to other forms of lung disease. Of all the types of organic dust, coal dust is the most important. Fibroses of the lungs observed in anthraco-silicoses are not caused by coal, but, as mentioned above, contained in it as an impurity of mineral dust, which includes quartz and silicates.
The admixture of mineral particles in coal dust can be quite significant; so, in brown coals it reaches 25-30%. Distinguishing charcoal dust particles from mineral particles under a microscope is quite difficult, since large black charcoal particles cover colorless mineral particles. The opinion that pulmonary fibrosis in these cases is caused by mineral dust is confirmed by the fact that the presence of an increased amount of silica is chemically determined in the lung tissue of workers who inhaled coal dust with an admixture of mineral.
However research recent years, conducted by the Institute of Occupational Physiology (Rabvin et al.), point to the possibility of developing pulmonary fibrosis under the influence of inhalation of pure coal dust, which does not contain either quartz or silicates. These fibroses are benign.
Dust and pneumonia. The penetration of dust into the alveoli may be accompanied by the formation of inflammatory exudate in them. This exudate, in the presence of sufficiently virulent pathogenic microbes, can spread to a more or less extensive area of \u200b\u200bthe lung tissue and give a clinical picture of lobar, or lobular, pneumonia. These acute dust pneumonias are possible primarily in workers engaged in grinding the so-called Thomas slag, a by-product of steel production.
The latter thanks to the great the content of phosphorus salts is a valuable artificial fertilizer. To make the slag usable, it is ground into a powder. During the period when the milling of Thomas slag was introduced at the factories, workers, according to foreign authors, often experienced pneumonia with a severe course and a high percentage of mortality, and the death rate from pneumonia among workers engaged in grinding Thomas slag was 30-60 times higher than the rest of the population of the same age.
Considered form pneumonia refers most often to lobar. Its outcome in cases ending in recovery may be a sharp emphysema. In addition to thomas slag, pneumonia is caused by dust of manganese ore (brown iron ore) and potassium dichromate. In Russia, these pneumonias are rare.
Along with the dust lungs spores of various fungi can be introduced - mold, radiant, etc., which leads to the development of so-called pneumomycosis. The most common infection is with Aspergillus species. Flour grinders, agricultural workers, workers in breweries, workers dealing with animal hair, etc. are susceptible to infection of the lungs with fungi. The disease proceeds either in the form of pneumonia or in the form of bronchitis, mostly sluggishly, with remissions, and in most cases ends in recovery.
vegetable dust lead to acute, subacute, as well as chronic lung lesions. Their mode of action has not been elucidated, and in some cases the harmful agent found in the vegetable matter of the seeds, such as certain proteins, alkaloids, or other irritating and toxic substances, is unknown; sometimes their harmful effect is due to biological pollution (bacteria, spores, mycelium) and mineral (silicium).
Danilov Alexander Gennadievich
Engineer-expert of LLC "GorMash-YuL", expert unified system conformity assessment in coal industry.
Co-authors: Grachev Eduard Alexandrovich - expert of the Unified Conformity Assessment System in the coal industry;
Kulchitsky Stanislav Vladimirovich - expert of the Unified Conformity Assessment System in the coal industry;
Galiev Marat Gaptullovich - expert of the Unified Conformity Assessment System in the coal industry.
The explosiveness of coal dust is determined by the physical and chemical properties of the developed mine seam and the mining conditions under which an explosion is possible.
The physical and chemical properties include: the stage of coal metamorphism, quantitatively expressed by the release of volatile substances, the content of ash and moisture in coal, the dispersion of floating and deposited coal dust. The mining conditions include: the concentration of suspended and deposited coal dust in the mine working, the source of ignition, the content of methane in the atmosphere.
The degree of influence of these factors on the explosibility of coal dust is different.
Influence of volatile substances.
It is generally accepted, according to research data from the research institutes MakNII, VostNII, etc., that with the growth of volatile substances (Vcdaf), the explosiveness of coal dust increases, and there is limit value the release of volatiles, at which the dust ceases to explode. At Vcdaf ≤ 6% - coal is not dangerous for dust explosions, with an increase in the yield of volatiles, the frequency of occurrence of non-explosive samples decreases, and at Vcdaf ≥ 15%, the coal seam is accordingly dangerous for dust explosions. For coals with Vcdaf >30%, the lower explosive limit of coal dust increases insignificantly and practically remains constant. As an indicator of the explosibility of coal dust in individual countries, different values of the release of volatile substances have been adopted. For example, in the UK, the limiting yield of volatile substances, which determines the explosiveness of coal dust, is 20%. In Poland, the Czech Republic and Belgium, coal seams with a volatile yield of more than 12-14% are considered hazardous in terms of dust explosion. In France, the explosibility of coal dust for each mine seam is determined by laboratory tests, regardless of the release of volatile substances. AT Russian Federation according to the current FNiP in the field of industrial safety "Safety Rules in Coal Mines", coal seams with a volatile matter yield of 15% or more, as well as coal seams (except for anthracites) with a lower volatile matter yield, the dust explosiveness of which has been established by laboratory studies, are considered dangerous for dust explosions and testing of coal dust for explosiveness. This is justified by a systematic analysis of data from tests of coal dust for explosiveness, the results of which are shown in Fig.1. It can be seen from the graph that at Vcdaf ≤ 6%, all tested samples of coal dust are non-explosive. With an increase in the yield of volatile substances, the frequency of occurrence of non-explosive samples decreases, and at Vcdaf = 15% or more, all tested samples of coal dust turned out to be explosive.
Fig.1. Dependence of frequency n of occurrence of non-explosive coal dust on the release of volatile substances Vcdaf.
Based on previous studies, both in our country and abroad, it can be concluded that the coal dust of mine seams with a volatile matter yield of 6% or less is non-explosive according to accepted test methods. However, the release of volatile substances is not always an unambiguous indicator of the explosibility of coal dust. Reason is difference chemical composition volatile substances. Studies of the chemical composition of coal thermal decomposition products have shown that the main components of volatile substances that determine the explosiveness of coal dust are resinous substances and unsaturated hydrocarbons on the basis that resins begin to be released at lower temperatures, and unsaturated hydrocarbons have a low concentration explosive limit. The influence of other components of volatile substances is of secondary importance. However, no quantitative dependence of dust explosibility on the yield of these components has been established and no explanation has been given for the fact of explosibility of coal dust with a yield of volatile substances less than 10%, which practically do not contain resinous substances.
Based on the concept of the structure of coal matter, under thermal action on pulverized coal particles, first of all, the chains of side groups of molecules that are most remote from the central core are opened. In this case, gaseous, liquid and solid substances are formed from the products of thermal pyrolysis, synthesis, and residues of side groups. Gaseous products are a mixture of gases consisting of CO2; CO; H2; CH4; C2H6, etc. Given that the process of coal dust explosion proceeds quickly, during the preparation for it, the particles of the dust cloud are heated to a temperature much lower than the temperature of the ignition source (flame front). Dust pyrolysis occurs in a low-temperature regime, and gaseous products are characterized by a high content of methane, its homologues, and unsaturated hydrocarbons. The latter makes it possible to consider that the main component of gaseous pyrolysis products, which determines the explosiveness of coal dust, is methane (CH4). This is also confirmed by the fact that with an increase in the yield of volatile substances, the content of CH4 in pyrolysis products increases (Fig. 2.).
Fig.2. Dependence of methane content in gaseous workings of coal pyrolysis products V on the yield of volatile substances Vcdaf.
For coals with a volatile matter yield of up to 30%, there is a strict pattern between the methane content in the pyrolysis products and the degree of dust explosibility, which is used for the appropriate classification of coal seams.
The presence of combustible gases in the atmosphere. So, in the presence of methane in the production, the lower concentration explosive limit of coal dust decreases and is determined by the following empirical formula: ; at CH4=0.5% - 30 g/m3; at CH4=2% - 10 g/m3).
Influence of nonflammable substances and moisture.
Mineral non-combustible substances are constituents of coals and, according to their origin, can be divided into two groups, one of which is internal or constitutional ash, and the second is external. Constitutional ash is characterized by the fact that non-combustible substances are chemically bound with coal matter, evenly distributed in coal, and, consequently, in dust. Its content is low and usually does not exceed 2%. The content of external ash is mainly determined by the technology of coal mining. Ash as an inert additive reduces the explosibility of coal dust due to the shielding effect and the cost of heat for its heating, thereby reducing the heat balance of the system. In addition, non-combustible solids mixed with coal dust, being in the state of an aerosol, dilute the concentration of explosive particles and, at the stage of thermal pyrolysis, contribute to the termination of reaction chains. These properties of non-combustible substances led to the use of inert dust for the prevention and localization of coal dust explosions.
The material composition of non-combustible components also influences the explosive properties of coal dust. For example, if they are represented by carbonates, then when heated to 1073 K and more, significant amount(12-15% vol.) carbon dioxide, the admixture of which in the products of pyrolysis increases the concentration limit of explosiveness of combustible gases.
The influence of the content of non-combustible substances on the explosiveness of dust in layers of different stages of metamorphism affects differently. For coal dust with a yield of volatile substances less than 15%, the influence of the content of non-combustible components is more significant than it is with a higher yield of volatile substances. MakNII research has established that the explosibility of coal dust with a volatile matter yield of less than 15% is significantly reduced at an ash content of 20-30%. In some cases, this ash content is sufficient to completely neutralize explosive dust. With an increase in the yield of volatile substances by more than 15%, the degree of influence of natural ash content decreases. When the output of volatile substances is more than 30%, the natural ash content does not affect the explosiveness of coal dust.
Moisture present in coal manifests itself in two ways. On the one hand, it acts as an inert additive, on the other hand, as a factor contributing to the autohesion of small particles, leading to a decrease in the specific surface of the dust and, consequently, to a decrease in its explosiveness. Due to the high specific heat capacity and heat of evaporation, with an equal mass, it absorbs 4.5-5 times more heat than inert dust. The content of natural moisture in coal is insignificant and does not have a noticeable effect on the explosibility of coal dust. But if the deposited dust is moistened to 12% or more, then it is not able to move into a suspended state; and create explosive concentrations. At a humidity of 20-25%, dust usually does not explode.
Influence of the disperse composition of dust.
Numerous studies have established that the degree of dispersion is an essential factor determining the explosiveness of coal dust. Particles of different sizes less than 1000 microns take part in the dust explosion, and the explosibility of coal dust increases with increasing dispersion.
The influence of the dispersed composition of coal dust on its explosibility was studied in detail at the MakNII. The studies were carried out in laboratory devices with dust from mine layers of various stages of metamorphism of the following fractions: 600-300; 300-150; 150-75; 75-50; 50-30; 30-10 and less than 10 microns, and for coal with a high yield of volatile substances (Vcdaf = 40.5%) less than 5 microns.
On fig. 3 shows the dependence of the pressure (P) developed during the explosion of coal dust on the average size of its particles (d).
As an indicator of explosiveness, the specific pressure developed during a dust explosion in a closed volume is taken. In two cases, a decrease in the explosibility index was observed for a fraction of less than 10 microns. The reason for the decrease in this indicator for fine dust is autohesion, which is more effective, the finer the dust. This was proved with the help of a small addition of coarse dust, which sharply reduces autohesion, but practically does not change the total specific surface area. As a result of this addition, a significant increase in the explosibility of dust fractions of less than 10 μm was achieved.
Noteworthy are the studies carried out in Poland. In an experimental mine, he studied the explosiveness of dusts of the same layer containing 85% of particles smaller than 75 microns in one and 96.3% of particles smaller than 15 microns in the other. For the first dust, to neutralize its explosiveness, an addition of inert dust was required, equal to 4 kg per 1 kg of coal, for the second - 6.7 kg. According to the results of this work and other studies, it was found that particles smaller than 1000 µm take part in the explosion, fine coal dust with particle sizes of 60–100 µm has the highest explosive properties, i.e. dust passing through a No. 80 sieve has the highest explosive properties of coal dust with a particle size of 45 microns.
Based on the foregoing, it can be concluded that the explosiveness of coal dust increases with increasing dispersion, so coal dust in mine workings mines, as they move away from the source of dust formation, are potentially more explosive.
The amount of suspended dust. Dust suspended in the air is called dust aerosol. With a very high degree of dust, the distance between individual dust particles is very small, and the dust is non-explosive. By increasing the distance between the dust particles, we reach a point where ignition and explosion are still possible, this is called upper limit explosiveness. A further increase in the distance between the particles until the explosion becomes impossible, leads to the so-called lower explosive limit. The most destructive effect is the explosion of a dust-air mixture containing 300 g of dust in 1 m3 of air. For the most dangerous coal dust, the lower explosive concentration limit is 10g/m3.
Chemical and mineral composition of dust. Dust, with the content of non-combustible components in it from 60-70%, is not explosive.
List of used literature:
- Federal rules and regulations in the field industrial safety“Safety rules in coal mines, approved. by order of Rostekhnadzor dated November 19, 2013 No. 550.
- Federal norms and rules in the field of industrial safety "Instructions for the fight against dust in coal mines", approved. by order of Rostekhnadzor No. 462 dated October 14, 2014.
- GOST R 54776-2011 Equipment and means for the prevention and localization of explosions of dust-air mixtures in coal mines, dangerous for gas and dust.
Another environmental scandal related to coal - the residents of the village of Vanino suffer from coal dust, which they are generously endowed with by the port of Vanino. "Oxygen.LIFE" read the local media, and came to the conclusion that at this point on the map of the Far East, there was clearly no dialogue between big business and the local population. And it will be quite difficult to cut this knot now.
Rosprirodnadzor reacted to the massive complaints of residents of the village. Vanino (Khabarovsk Territory) "for air pollution in connection with the sorting of coal at the site of Port Vanino OJSC", one of the largest Far East. Based on the results of an administrative investigation, the service banned the operation of ten crushing plants that emit harmful emissions. She also demanded to suspend the activities of the entire enterprise for up to 90 days (there is no court decision on this matter yet; UPDATE - on February 3, it became known that the port was fined 250 thousand rubles for emissions).
Rosprirodnadzor received complaints from the local population throughout the past year, Vanino Commercial Sea Port OJSC (one of the key shippers of Port Vanino OJSC, controlled by Mechel Group and specializing in coal exports) was brought to administrative responsibility four times for environmental violations . But they did nothing to fix it. After another complaint, Rosprirodnadzor decided to check the process units used at the enterprise for sorting coal. And I found out that some of them were exploited illegally. They were sealed on January 27th. “The volume of unauthorized emissions in Rosprirodnadzor is called “significant” for the quality of atmospheric air and water area in connection with the “round-the-clock work of the port,” writes the Kommersant newspaper.
Nevertheless, last Sunday a protest rally was held in Vanino against air and water pollution of Vanino Bay (Tatar Strait) with coal and alumina dust (the port specializes in processing coal and alumina). It was attended, according to various media, from 500 to 1000 people. "Cargo handling, including processing of coal and alumina open way, is produced in violation of technology, despite the program signed last year with the government of the Khabarovsk Territory to improve environmental safety. Coal and alumina dust not only harms the health of port workers and residents of the village, but also represents an explosive mixture, which in one more parameter makes the enterprise a dangerous production,” the resolution of the protesters, which was sent to everyone top management country, as well as the authorities of the Khabarovsk Territory.
Among the demands of the rally: "immediate stop of mobile sorting, crushing plants, screens in the port of Vanino", "immediate start of modernization of coal processing in compliance with environmental safety", development and implementation of a regional program to improve the environment in the village, etc. However, as IA REGNUM recalls, “since the sale of the controlling stake in OAO Vanino Commercial Sea Port to Mechel, the Vanino region has been unresting over violations of environmental laws. For the first time, residents of Vanino came to the rally in May 2013. At the same time, on behalf of the governor of the region Vyacheslav Shport An environmental program was developed and approved, but not implemented. Another program was developed and approved by the regional government in 2016, but it was not implemented either.”
Among the demands of the rally in Vanino: "an immediate stop of mobile sorting, crushing plants, screens in the port of Vanino"
It's been going on for three years
The problem with coal dust in Vanino is a long-standing one, according to local media - it has been going on since 2012, when, according to environmental activists, the port began to increase coal transshipment to the detriment of other types of cargo (but in the interests of the new owner). Last year, the residents of Vanino even promised to go on the rails if the problem with open transshipment of coal was not resolved, Pacific Star writes. “You see, even with the active intervention of the regional authorities, the Port Authority promises a lot, but does nothing. For a whole year, the supervisory authorities gave the port management to correct the situation, but, alas, the port ignores all the requirements ... If earlier coal was shipped from points as far as possible from the village of Vanino, now coal is literally under the windows, from crushing plants to the windows of the nearest house 150 meters norm of at least 500 meters,” the chairman of the initiative told the media environmental group"Vanino" Vadim Moskvichev (quotes - according to the newspaper "Pacific Star" and "Kommersant").
According to the eco-activist, the problem with coal dust is especially aggravated in winter: “They bring frozen coal. These machines, which are called crushers, seeders, work with him. They drive the coal, sift it, and in the process of running, this active dusting is created. A coal curtain stands over the villages of Vanino and Toki. People are suffocating, I am already silent about the fact that they are sick. Moskvichev also added that as soon as the installations stopped working, the people of Vanino immediately felt it, indeed, there was much less coal dust.”
“The owners of the port, who live far from Vanino, will leave their children multi-billion dollar accounts in foreign banks. And what will they leave for the children of those who live today in Vanino, who work in the port? Dust, dirt and ruined health? We do not intend to put up with this state of affairs and, together with the residents of the Vaninsky district, we will seek respect from the owners of the port for the people who live here! Elena Greshnyakova. And acting heads of the Vaninsky district Nikolai Ozharovsky added that the Vanino port is the only enterprise that "does not take part in the socio-economic development of the region": "Vanino port has not given the region a penny since the change of ownership."
"We do our best"
The management of the port of Vanino states that the accusations against the enterprise of inaction in connection with coal dust are unfounded. “The administration of the enterprise is open to dialogue with the public and regularly posts on its website and in the media information about the implementation of the “Action Plan for the Prevention of Coal Dust Pollution in the Port of Vanino”, approved by the government of the Khabarovsk Territory. In 2017, the enterprise intends to increase the amount of funds allocated for the implementation of the environmental program," the port's press service said in a statement. And, indeed, the news feed of the website of Port Vanino OJSC is more like a summary of the ongoing battle with coal dusting.
“Unfortunately, dusting occurs from coal - this is an inevitable consequence of the work of any port complex dealing with coal. This problem is acute in the period of negative temperatures. We understand the public concern, we share it and we will apply all available methods to prevent dusting, ”says CEO OJSC "Port Vanino" Valery Balakin. According to him, the company has already studied the experience of the largest coal terminals in the Baltic States, Europe and Korea, which use the clamshell transshipment technology.
And a number of measures have already been taken: “A snow generator is already working in the port to suppress dust. We bought four more similar units, they will be launched in February. In conditions of negative temperatures, this is the most effective technological solution for combating coal dust. The advantage of these installations is that they produce snow that effectively settles the dust suspension. Simplicity of a design provides reliability in operation. It is also important that this equipment will be used all year round, forming a water mist in summer.”
In addition, at the end of February, the company will purchase a vacuum device that will clean access roads and storage areas in the port, which will also reduce dust levels. “The next stage is the installation of special fences in all places where we store coal,” Balakin said. The work has already begun: a number of storage areas are fenced off with reinforced concrete slabs. Fencing slabs for the rest of the warehouses have been purchased and will be installed in the near future upon delivery of the necessary components.
In the second quarter of this year, the port expects the arrival of another expensive item - a high-speed vacuum loading machine designed to work in sea and river ports, or in industries where it is required to collect spills of dirt and debris, as well as coal, alumina, crushed stone, pulp, any bulk and liquid materials. The machine is a powerful industrial vacuum cleaner complete with a road sweeper, and it will allow efficient and continuous cleaning of the entire industrial area of the port.
Regarding the crushers, which were banned by Rosprirodnadzor, the press service of the port stated that “in order to reduce coal dusting, the port refused to transship coal that requires crushing before shipment. Crushing and screening machines are used exclusively as a magnetic separator - for the purpose of trapping metal inclusions in the incoming coal. Also, in order to reduce dusting, the port moved coal warehouses from the 9th and 11th berths to other areas of the port, remote from the residential area of the village of Vanino.
“Unfortunately, dusting occurs from coal - this is an inevitable consequence of the work of any port complex dealing with coal. This problem is acute in the period of negative temperatures.
Mechel will help
On January 25, Vyacheslav Shport, Governor of the Khabarovsk Territory, during a working trip, held a meeting with residents of the Vaninsky District, which was also attended by the Chairman of the Board of Directors of Mechel PAO Igor Zyuzin. The port mainly transships coal to the Mechel company, which has long-term contracts with coal consumers in the Asia-Pacific countries, supply failures for which are unacceptable and can lead to the loss of sales markets. Therefore, Mechel, as a client of the port, is interested in uninterrupted operation and further technological modernization of equipment and infrastructure, General Director of Mechel Trans Management Company LLC, a member of the Board of Directors of Vanino Port, said at the meeting. Alexey Lebedev.
He also added that “the company has extensive experience working with many European ports, where they have already solved the problem of dusting. The company, together with Port Vanino, will develop environmental measures and assist in organizing an effective dust suppression system in winter and summer.”
The governor also said that a special working group would control the progress of fulfillment of the enterprise's obligations to improve the environmental situation. “Compliance with environmental requirements is an absolute priority for us. We stand on the side of the citizens here, we will control the process and help them. We need healthy citizens who will help to make a profit,” Vyacheslav Shport noted. According to him, the group will definitely include representatives of the public, the government of the region, the district administration, deputies and the port authorities. “Together we will form an action program to improve the environmental situation, necessarily with financial support. We will coordinate the document with Mechel and together we will monitor its implementation. In my opinion, two weeks are enough to draft such a program,” the head of the region said.
ONF: business needs to increase its environmental responsibility
The “Vaninsky case” testifies not only to the difficulties of dialogue between big business and the inhabitants of a small but proud village, which, by the will of fate, has become one of the many remote production sites for the business giant. Moreover, according to Kommersant, it is not critical: in case of problems with transshipment at the port of Vanino, coal from Mechel can go to other Far Eastern ports, for example, to Posyet.
But this case also showed that the administrative levers for violators are weak and do not always work as they should. It is no coincidence that the Special Representative of the President of Russia for Environmental Protection, Ecology and Transport Sergey Ivanov not so long ago he announced that fines for those enterprises that refuse to modernize their production facilities will increase several dozen times.
Experts from the Center for Public Monitoring of the All-Russian People's Front (ONF) on environmental issues and forest protection said that the current fines for enterprises that seriously pollute the environment do not at all encourage them to take a more responsible attitude towards nature and modernize equipment. According to the coordinator of the Center Vladimir Gutenev, "in the vast majority of cases, these figures do not attach importance to the damage they cause to the environment and try to hide it in every possible way, and when violations are recorded, they prefer to limit themselves to fines, rather than eliminating the causes of their occurrence."
At the same time, according to Gutenev, the topic of environmental modernization Russian enterprises is not new at all and has been raised repeatedly over the past decade: “A significant part of enterprises not only have not carried out modernization, but also do not plan to take action in this direction. At the same time, the problem of pollution environment does not always refer to old enterprises that have been operating for decades. There are cases when newly created enterprises do not pay due attention to the environmental consequences of their activities.
The ONF is in favor of strengthening control over the mandatory modernization of industries that cause environmental harm. “Perhaps, under the control of oversight agencies, the preservation of a favorable environment for the local population will become a priority production task", - summed up Gutenev.
By the way, the problem of coal dust is relevant not only for Vanino. A video has already appeared on Youtube, made in one of the schools in Nakhodka (Primorsky Territory), located close to the coal terminal (probably the port of Vostochny). “Dirty, they don't get washed, we have to breathe it. Now I'll show you, look at the floors, okay floors, look here. Do you see it? This is what we all breathe, ”the voice of the student is heard. In addition to textbooks and notebooks, students of this school bring a pack of napkins with them to wipe their desks and chairs. Each pack is enough for about a couple of days, Nakhodka TV reports.
Vladimir Gutenev: "A significant part of the enterprises not only have not carried out modernization, but also do not plan to take action in this direction"
The properties and characteristics of coal dust include the size of dust particles. Coal dust consists of particles up to 300 microns in size with a predominance of fine fractions. Most of all in coal dust particles ranging in size from 20 to 50 microns, depending on the fineness of grinding. Dust, especially coal rich in volatiles, is prone to spontaneous combustion, which is one of the main causes of explosions in dust preparation systems. The risk of spontaneous combustion of dust is also included in the properties and characteristics of coal dust, it increases with increasing ambient temperature and in contact with hot surfaces. The most explosive is the dust containing particles less than 200 microns. To characterize the grinding properties of the fuel, the so-called laboratory relative grindability coefficient of the fuel is used. These are important properties and characteristics of coal dust. It is understood as the ratio of the specific energy consumption during grinding (in a standard laboratory mill) of the reference and test fuels. The properties and characteristics of coal dust also include the quality of the dust particles. The quality of the dust obtained in dust preparation plants is usually characterized by the fineness of grinding, determined by the sieving of the sample on sieves with different hole sizes. As a result of sifting, the rest of the dust on the indicated sieves is determined, which characterizes the fineness of grinding. According to the sieving data, the dependence of the residue on different sieves on the particle size (sieve opening size) can be built, which is called the grain characteristic of the dust. Residue values on sieves 90 and 200 µm make it possible to judge the uniformity of the dust. Obviously, the more uniform the dust, the less electricity has to be spent on its preparation. The greater the difference between the residues on sieves 90 and 200 microns, the dust is more uniform in composition. Distinguish between bulk and apparent density of dust. Bulk density is understood as the ratio of the mass of dust to its total volume (the total volume, consisting of the volume of the solid phase of the particles, the pores inside the particles and the air gaps between the particles). The apparent density of dust is understood as the ratio of the mass of dust to the total volume occupied by the solid phase of dust particles and the pores inside the particles. Bulk density is used when calculating the capacity of dust bins for dust storage. Apparent density is used in the design of dust feeders, separators and cyclones. The moisture content of the finished dust affects the conditions of its ignition and the course of the combustion process. The lower the moisture content of the dust, the easier it ignites and burns faster. Usually, dust drying is carried out in such a way that its moisture content is close to the hygroscopic moisture content of the fuel (Wg - see § 2-2).
Fuel combustion processes
Combustion is a rapid combination of oxygen with combustible fuel elements (carbon, hydrogen and sulfur) and is accompanied by the release of heat and light. Oxygen is supplied to the furnace with air. Dry air consists of two elements: 21% oxygen and 79% nitrogen. Only oxygen is involved in the combustion of fuel. In order for the combustion of fuel to begin, it is necessary to bring the temperature to the ignition temperature, at which combustion occurs independently, without heat supply. The ignition temperature depends on the type of fuel and the conditions in which the combustion process takes place. The ignition temperature of fuel oil is 500-700 °, coal 500 °, anthracite 700 °, firewood 300 °. Carbon is the main constituent of any fuel, it burns or in carbon dioxide(CO2), or into carbon monoxide (CO). When a sufficient amount of air (and hence oxygen) is supplied to the furnace, the carbon combustion reaction proceeds completely. With a lack of air, the carbon combustion reaction will not proceed completely, and much less heat will be released. Due to the incomplete combustion of carbon, not carbon dioxide is obtained, but carbon monoxide. The second combustible element that is part of the fuel is hydrogen (H2). The combustion of hydrogen is also accompanied by the release of heat. From the equations of combustion of carbon as the main combustible element of any fuel, it can be seen that with incomplete combustion of carbon, i.e., when combustion occurs with a lack of air and as a result of combustion carbon monoxide (CO) is obtained instead of carbon dioxide (CO2), heat will be released three times less. This implies the conclusion that it is necessary to strive to create such conditions under which the combustion of the fuel will occur completely, that is, with a sufficient amount of air so that carbon burns into carbon dioxide (CO2). Knowing the composition of the fuel of each grade, it is possible to calculate the amount of air required for complete combustion. If we divide the amount of air actually introduced into the furnace for burning 1 kg or 1 m3 of fuel by the calculated amount of air, i.e., by the amount of air required for the same purposes, but determined as a result of calculations (theoretically), we get a number called the excess air ratio. Therefore, the excess air coefficient is the ratio of the air practically necessary for burning a unit of fuel (kg, m3) to the calculated (theoretical) amount of air. It is always necessary to strive for complete combustion of the fuel with a minimum excess air ratio.