Method for air conditioning, separator of coal bed gases, mine separator with net

FIELD: technological processes.

SUBSTANCE: invention may be used in mining industry. Separator intended for separation of coal bed gases is placed in cavity of mine. Hydrocarbons separated in separator are exhausted via gas line, and volume of gases discharged from mine is substituted with atmospheric air. Separator comprises body with nozzle of gas inlet 14, nozzle of light gas discharge 12 and nozzle of heavy has discharge 1, engine 20. In toroidal cavity 5 of separator body there is radial-axial centrifugal compressor installed with hollow blades, in which frontal slots 1 and rear slots 2 are provided. Propeller 10 is fixed on tubular extension of shaft 11. To inner surface of propeller 10 there are blades of radial-axial centripetal compressor 9 fixed.

EFFECT: efficient separation of heavy and light gases, reduction of power inputs for air conditioning in mine.

3 cl, 6 dwg, 2 tbl

 

The technical field relates to a group of inventions

Group of inventions relates to an air conditioning (gas), including the separation of hydrocarbons in underground mining.

The level of technology

We will arrange, within the framework of this review, to name a geometrical figure formed by the rotation of the elongated powellites around an axis parallel to the axis of powellites lying in the plane of powellites, but not crossing, the doughnut, if the top of powellites is farther from the rotation axis than the axis.

Air conditioning (gas) - bringing it more favorable for human life, machines and mechanisms.

Separator (<.separator - separator] - apparatus for separation of the mechanical force of some substances from other or separating them from the mixture.

There is a method of conditioning air cavities underground workings, based on the use of special ghatotkacha installations. The essence of this method lies in the fact that air conditioning is used ghatotkacha installation, forcing air generation in pipeline gas exhaust system. In this case, applying high pressure (up to 1500 daPa) and high performance (up to 1800 nm3/min) ghatotkacha fans technical characteristics is which can drain methane-air mixture with a methane concentration of 0-100% (see "Principles of mining", Avimet and other Kuzbassvuzizdat, 2006, S.255) (prototype claim 1 of the formula).

This method is cost-effective and achievable effect has reached the leading position. However, in the latter years of the accident in the off gas suction systems questioned its safety. "When applying it ...sucked gas-air mixture may acquire properties that cause it to auto-ignition and even explosion" (ibid, s-259). In addition, the abstraction of the production of a methane-air mixture requires its replacement by atmospheric air, which is supplied by worked-out space. However, the speed of the air flow in the formulation is limited.

As an analogue to the invention, it is possible to specify inventor's certificate SU 1793067 A1, which describes a method of cleaning mine air from dust and harmful gases in the manufacture of blasting and device for its implementation. The essence of the method is to create a rotating flow of polluted air, while it is repeatedly treated with dispersed active liquid and passed through a filter with catalyst. As an active fluid using an aqueous solution of hydrogen peroxide, and as a catalyst for the filter granules of iron ore. The disadvantage of this method is the introduction into the cavity generate active substances is comparatively low the traveler productivity and efficiency.

Machine for compression and movement of gases under pressure will be referred to as a compressor. By type of actors compressors will be divided into centrifugal and centripetal, which we will distinguish in the direction of gas flow their action. For example, quite widely used radial centrifugal compressor in which the gas motion is directed away from the axis of rotation of the impeller to the ends of the blades. As an example of its application can be called a "fan"used to separate grain from the chaff (prototype 2 formulas). In her circular motion of the blades of the impeller, the air is put into rotation. At the ends of the blades pressure by the centrifugal force increases, and in prisna reduced. The blades are placed in a circular cylindrical casing. Through the ends of the casing enters the air in Prienai space. Cowling cowl cut out a rectangular box in front of rolling weed seeds. Grain less change the direction of its movement by the action of the air flow, and cocklebur and dust are carried beyond the limits of "winnower".

As a counterpart, you can specify inventor's certificate SU 1729601 A1, which describes a centrifugal separator. The increase in the degree of purification is achieved by increasing the "separation factor", which is created by translating the suspension aerosol and action center the panorama forces.

Analog can be considered and the invention of U.S. patent US 4145197 A, which describes a device for separating dust particles from the air in which the dust is captured by the sprayed water.

A common shortcoming of these alternatives is the use of water sprays for dust.

The essential point of the compressors is available, along with the radial motion of the gas, its simultaneous displacement in a direction parallel to the axis of rotation. This shift in centrifugal machines can be observed. It is the result of the discharge gas in pricebuy region, because we can talk about radial-flow centrifugal compressor. Radial-flow centrifugal compressors are unknown to the applicant. Axial movement of the air in the fan, in his opinion, does not contradict the last statement, so as not caused by compression and rarefaction of air, which formally corresponds to our definition of radial-axial centrifugal compressor.

Centrifugal force is used in a device such as a centrifuge, which can be considered as a kind of radial centrifugal compressor.

For conditioning of gases in terms of mine production is necessary to simultaneously solve the problem of separating gas from suspended particles of dust and mist. This kind of problem is solved in the patent RU No. 2293761 Ro the Cova I.S. (prototype p.3 formula), where it is shown that the use of mobile grid allows to achieve an acceptable level of cleaning gas from the aerosol.

As peers, you can specify author's certificate SU 1731298 A1 (Centrifugal classifier), SU 450418 A3 (Vortex cleaner), SU 670731 (Centrifugal cyclone separator). Their disadvantages are the relatively low productivity and efficiency in relation to hydrocarbons.

Disclosure of inventions

The invention according to claim 1 of the formula is a method of conditioning air in the cavity of the mine workings.

The technical result consists in: improving the working conditions of miners and their safety; reducing energy consumption for air movement for ventilation of underground workings, corrective action load restriction on cleaning the face on the gas factor ("gas barrier").

The specified problem is solved by the method of conditioning air in the mine development at which its lead in the development, the air is output through the pipeline and replace naturally. When this air conditioning are in relation to hydrocarbons, which are output by the pipeline and replace all of the volume of atmospheric air.

The invention according to claim 2 of the formula is the creation of the separator, providing separation of the gas extracted from coal seams, heavy is small and light fraction.

The technical result is achieved by increasing the concentration of light hydrocarbons in methane-air mixture that is extracted from coal seams by suction, first applied the mechanical separation of hydrocarbons.

The specified problem is solved by the separator gas in coal seams. It includes a housing located on the connections of the input and exhaust gases, engine, radial-flow centrifugal and centripetal compressors, impellers, blades which rotate around the axis of the hollow propeller. While the blades of the impeller of the centrifugal radial-axial compressor performs hollow. They supply slots in the front and rear surfaces. The slots extend from the propulsion to the toroidal cavity of the compressor. The ends of the blades choke. The plugs perform radially oriented channels adjustable section. The upper edges of the blades are bent in the direction of rotation, the bottom and end in the opposite direction. Input and output gases in the cavity of the rotation of the impeller leading through the plate lattice in the form of a circular ring width from the edges of the donut to the surface of the thruster without touching it. Radial and circular plate grids set at an acute angle to the axis of rotation. The propeller is fixed to the tubular extension of the motor shaft, articulated with the body through the your two bearings. To the inner surface of the mover fixed blade radial-flow centrifugal compressor. The cavity of the tubular extension report with the cavity of the propulsion device and the pipe outlet is relatively light components. Relatively heavy components are selected through a nozzle with an adjustable cross-section, which is cut in the most remote from the axis of rotation spot doughnut. The input gas in this tube passes through a dead-end tunnel.

The invention according to claim 3 of the formula is a creation of mine cage with mesh for air separation output component groups.

The technical result of this problem is expanding Arsenal of technical means of air conditioning cavity mine workings, in particular, the creation of opportunities for the conclusion of the oral production of hydrocarbons and other component groups of the air output.

The solution of the stated problem is achieved by creating a mine cage mesh. Known characteristics of the device are the centrifugal and centripetal, centrifugal and axial-flow compressors, propulsion, engine and valves. While one unit is put together from two to eight centrifugal and two centripetal radial-flow compressor. The blades of the impellers all compressors are fixed on a common vehicle. The input cavity from top to protect what Ontario, which secure the pipe with flange removal of light gases, and a perimeter enclosing bars connecting the umbrella with the donut upper radial-flow centrifugal compressor. The blades of the input radial-flow centrifugal compressor smoothly bent in the direction of rotation from the end to the beginning of the circular plate lattice. The upper edges of the blades along the entire length attached to a circular ring. The lower edge is also attached to the circular ring width from the ends to the beginning of the circular plate grids, and then (up to the surface propulsion) are bent in the direction opposite to rotation. On the ends of the blades of the input radial-flow centrifugal compressor fix a fine mesh in the form of a circular cylinder.

Brief explanations of the tables and schematic drawings.

Table 1 presents the approximate composition of the mine atmosphere, and quantitative characteristics of their contents are given for the Earth's atmosphere. For gases, characterized by mine workings, their quantitative content differs from hydrocarbons. In the footnotes below for more information. The table has 19 rows and 8 columns. The first row contains column names, in the subsequent quantitative characteristics of gases.

Table 2 illustrates the differentiation of gasow cavities of the blades of the impellers depending on their density and the distance from the axis of rotation by comparing the pressure gradient [grad p = density x acceleration). In the note to table indicates the pressure gradient of the atmosphere at the Earth's surface.

Figure 1 - blade radial-flow centrifugal compressor; the position of the sections, plugs and channel it, the location of the front and rear slots. Illustration 2 formula. 2, 3, 4 - profile of the blades on AA', BB' and CC'. Illustration 2 formula. 5 is a separator gases of coal seams. Illustration 2 formula. 6 is a mine cage with a grid, illustration, paragraph 3, of the formula.

The implementation of a group of inventions

1. The advantages of the proposed method of air conditioning underground goaf consider the example of a coal-mining area 24-47 OAO mine them. After S.M. Kirov in Kuzbass ("Principles of mining", s.312, table 11). Measurements in the ventilation hole 24-46 07.04.2005 from the well was pumped 660 m3/min of air. While methane emission rate was 15,97 m3/min, which is equal to 2.42% of the volume of air extracted from the mine.

The amount supplied in the production of replacement air cannot be arbitrarily large. If you increase the speed of the air, "to work in a mining face will be impossible due to the high dust and zero visibility" (ibid, s-254). With increasing depth of the mines increases and methane emission rate", reaching 60 m3/min, which allows us to talk about "gas BA is here" productivity growth and the increasing depths of the mine workings. Separation of hydrocarbons directly in the elaboration and conclusion from its cavity, with abandonment of nitrogen and oxygen, reduces the amount of air injected into the production, significantly reduces gas barrier, improves health and safety of miners and the performance of the technology, improves the environment, creates an additional amount of energy.

2. In 1940-1941 in England and the United States started work on the study and application of methods for the separation of the isotope uranium-235. The end result was the formation of a set of technologies for the separation of isotopes, in which there is mechanical separation. It is called by the method of mass-centrifugation (Handbook on nuclear physics", translation from English under the editorship of academician. Luarsabovich, M.: Gosizdat, 1963, s).

Ibid at s.353 the definition of partition coefficient:

,

where ζ is the coefficient of separation;

n'1- the number of atoms in one gram of mass m1after separation;

n'2- the number of atoms in one gram of mass m2after separation;

n1- the number of atoms in one gram of mass m1before the separation;

n2- the number of atoms in one gram of mass m2prior to the separation.

In addition to the separation factor of the authors of the "Handbook..." point and on other process parameters, among which marked: 2 output separated products; 3) the total amount of material in the separation process; 4) the time required to achieve a stationary operating conditions or equilibrium process; 5) the efficiency of the process.

For the separation of isotopes of uranium-235 is used centrifuges with great speed, "causing a lot of mechanical difficulties, and the separation factor depends on the difference in mass of isotopes". Judging by the formula (1), it is directly connected with difference values relative masses. The method is successfully applied for the separation of uranium isotopes using uranium hexafluoride" (UF6). Molecular weight hexafluoride uranium-235 349 Amu From stable hexafluoride uranium-238, the molecular weight of 352 u, its just 3 Amu, or about 0,86% of the mass of the molecules.

The mass of the molecules of argon 39,948, oxygen - 31,9968 Amu (see table 1). The difference of mass is 7.9512 Amu relative to the mass of oxygen difference relative masses is 24,85%, and in relation to the mass of the argon - 19,90%, 23.1-28,9 times more than in the separation of uranium-235. Accordingly, reduced requirement for speed and mechanical properties of materials centrifuges. This fact introduces a method of mass-centrifugation in the category of technologies in the public domain.

The proposed separator gas coal seam includes a radially-is sevie centrifugal and centripetal compressor, to distinguish which presents figures 5 and 6 on the arrows on the blades of the impellers, the pointing direction of the gases. We will, in addition, to distinguish between the front and rear surfaces of the blades of the impellers. Because the blades of the impellers, radial-flow centrifugal compressor is hollow, there is a need to distinguish between the inner front and inner rear surfaces. In the front and the rear surfaces of the blades are made of radial openings for the intake and bypass gases, area and shape of the cross sections are, their location and the length must match solvable technical problem.

Frontal movement of the blades of all of the compressors in their rotation provides capture, compression, axial displacement and separation of the gas, whereby the heavier molecules, so they are closer to the surface of the blade. Relatively light molecules outside of the cavity of the blade continues its movement in the direction defined by pulses received from its upper edge and the front surface. Passing through the front slot 1 into the cavity of the blade molecules lose the axial velocity. The action of the inner surface of the back of her hand going to the bottom of the cavity, where, esclavas reach the top, dropping a light fraction decreases in the rear region of the blade through the back of the slot 2, is where she picked up another blade and its action is directed down on the blade of the output radial-flow centrifugal compressor.

The gas in the cavity is forced to rotate together with the blade. The centrifugal force it rapidly moves to the end of the blade, which is muted. The consequence of this is the formation in the cavity of the blade radial gas column extending from the cover plate 3 before the back of the slot. Accordingly, it is separation in radial and vertical directions and the bypass light gases through the rear slot. The stub end of the blade provide channel 4 with an adjustable cross-section for the passage of a given amount of gas reaching the set pressure for him.

Obviously, the diameter of the channel stub specifies the expiry time of the cavity of the blade of the gas in the volume column of gas. This time should be sufficient for "surfacing" the force of Archimedes molecules detachable light gases. Otherwise, they will reduce the separation factor, having the toroidal cavity 5. This time there should be more than sufficient in extent, are beyond the scope defined by the difference of molecular weights, otherwise it will reset the heavy fraction. Respectively will be reduced and the separation factor.

Table 2 (from the fourth to the seventh column) shows the pressure gradient in the layers column gas cavity of the blade in the closed channel end caps and the rotation of the blade with a speed of 50 Rev/sec. The table shows that the creep is he, when a sufficient number of xenon will not be able to take the pole position not only at the level of 0.5 m, but also on any other level, and therefore must leave the cavity. Xenon in the air 10-6%, butane, isobutane and propane can exceed 3-4%. To separate them from the following gases behind them, and together with xenon, krypton and ozone, the content of which together do not exceed a thousandth of a percent. Mol of propane equal 44,068, mol argon 39,948, their difference - 4,12. The difference of the relative masses of about 10%. Mol of oxygen equal 31,9968. The difference of propane is equal to 12.1. The difference of the relative masses of about 30-38%. Since argon is inert and its contents are slightly to simplify the configuration can be neglected his joining a particular faction.

Thus, a certain time is set by the pressure gradient, the difference in relative molecular mass, the volume of the column of gas in the blades, the cross-sectional area of the channel in the plug blades and the balance a mixture of gases. To manage them, we can taking into account these values.

Let us imagine that we have a rotating horizontal tube, which is attached to the ball. The ball in the tube acting centrifugal force, directed toward its open end, so that in the absence of friction radial velocity of the ball increases. At the exit of the tube, the ball will continue its movement in the direction of the resultant of the two is leaving: tangent to the trajectory of the end of the tube at the place of separation of the ball and in the radial direction. It can be stated that the gas coming out of the cavity of the impeller blade in the toroidal cavity of the compressor will contribute to the stratification of the gas in the cavity.

Located at the ends of the blades, the gas is compressed, and the compression process is practically isothermal, due to the fact that the blades are metal and intensively blown air streams. Leaving cavities, the gas is expanded, resulting in a temperature decrease. Compression, expansion and decrease in temperature may cause condensation to form part of a pair, which flows into the drive condensate 6.

The gas in the output radial-flow centrifugal compressor also compress, steam, condenses, falls into the storage tank condensate.

In the toroidal cavity is going relatively heavy gas, the selection of which lead through the stub tunnel pipe 7 with an adjustable cross-section. This adjustment allows to displace the lighter gases from the toroidal cavity in the lower chamber 8 of the separator, where they are captured by the blades 9, the lower edges of which are bent in the direction of rotation of the radial-flow centrifugal compressor in the cavity of the mover 10 and are directed into the cavity of the tubular extension of the motor shaft 11 and further to the exhaust pipe with the flange 12. While radial and circular plate grids set at an acute angle to the axis of rotation of the blades is La damping the rotation of the gas when entering the cavity.

Thus, the gases introduced into the upper chamber 13 of the separator through a pipe with a flange 14, by the action of the impeller is driven through a circular lamellar grating 15, divided into heavy and light fractions. In addition to the above elements figure 5 shows the shape of a toroid 16, the bent ends of the blades 17, the lower bearing 18, solenaye tubular extension shaft with the bottom 19 of the lower cavity of the compressor, the engine 20 and the upper solenaye bearing 21.

It is known that methane is the primary component of natural and mine gases, where its concentration ranges from 60 to 99%. Its molecular weight is about 16 Amu and we attribute it to light gases. The separator discussed above, will not be difficult to adjust to the separation of methane, helium and hydrogen from the gas, which is sucked off from the coal seams, and thus ensure stable operation of the boiler.

However, in addition to methane, natural gas may contain butane, isobutane, propane, ethane, ethylene and other hydrocarbons, which we refer to as heavy. Their content can be up to 30-40% and to present well-known energy value and risk (see table 1 and the notes thereto). Their discharge into the atmosphere along with the heavy components of the unwanted air and on environmental grounds.

3. Mine separator grid is a device skomponovano is from several (two to eight) radial-flow centrifugal and two centripetal. As an example, consider the action of the separator with four radial-flow centrifugal compressors. This choice is due to the fact that the composition of the air by the difference of the masses of the molecules, taking into account the conditions of coal mines can be divided into 5 groups. In the notes to tables, note the properties of the specific gas, which as a by-product can be removed and others, that will require an increase in the number of groups, or the use of separators according to claim 2 or 3 groups of gases.

Illustrates p.3 formula scheme presented on Fig.6. Here we see that above the entrance cavity of the separator stretched umbrella 22, which is fixed to the pipe with flange for removal of light gases. With a pipe through the bearing jointed tubular extension of the motor shaft, which is similar to claim 2 of the formula fixed propeller with fixed blades on it all involved compressors. The umbrella is attached to the upper edge of a cylindrical grating 23, which has its lower edge secured to the upper toroid radial-flow centrifugal compressor through pipe gas outlets 24 which assign the most serious of them. As indicated above (see point 2), this group of gases includes, in addition to xenon, krypton, ozone, carbon dioxide and argon, and heavy hydrocarbons, butane, isobutane, propane. Their content in the group may previse the ü 90%.

The second group is the oxygen of mass number greater than or equal to 32 Amu, is discharged through pipe 25.

The third group of molecules isotopes of oxygen, nitrogen and carbon monoxide with mass numbers lower 32, but large 28 is discharged through pipe 26. The quantitative content of these isotopes is very small, but in terms of excavation in the composition of this group will be composed of ethane and ethylene.

The fourth group - nitrogen and carbon monoxide with mass numbers equal to or smaller 28, will pass through the pipe 27.

The fifth group - neon, water vapor, helium and hydrogen, light gases will pass through the pipe with the flange attached to the umbrella. In terms of mining the main component of the group - methane.

Distinguishes mine the separator from the separator gas in coal seams and the presence of the input radial-flow centrifugal compressor 29. This compressor provides a slight increase in pressure in front of grille upper and subsequent compressors and gas stratification in the input cavity, while the gases are arranged in order of increasing mass number a in the radial direction, thereby reducing the time stratification in the cavities of compressor blades. For this purpose, the blades of the input radial-flow centrifugal compressor are curved from end to beginning of circular plate grills is, their upper edges along the entire length attached to a circular ring. The lower edge is also attached to the circular ring width from the ends to the beginning of the circular plate grids, and then to the surface of the mover edges are bent in the direction opposite to the direction of rotation. As in the previous case, the separator is equipped with a drive condensate 6. Differs mine air conditioning and the presence of a metal wire grid 30 in the form of a circular cylinder, which is fixed on the ends of the blades of the input radial-flow centrifugal compressor.

Let us assume that the distance of the grid from the axis of rotation equal to 0.5 M. When the engine speed 3000 rpm = 50 Rev/sec resulting centrifugal force prevents the buildup of sediment on the grid, i.e. the grid is inherent in the self-purification.

To assess its purifying action of the gas from suspensions will take advanced that the amount passed through her air of 600 m3/min = 10 m3/s ("Basics of mining. C, table 10); the height of the circular grid of 0.3 m of the surface mesh S≈0,94 m2and, accordingly, normal air velocity relative to the grid will be about 10 m/sec. The linear speed of movement of any grid cell will be 157 m/s. When the thickness of the wire mesh 5-10-4m and the same window size of the cell for its change will require 1·10-3 m / 157 m/s = 6,4·10-6sec. During this time, the suspension will move at 10 m/s × 6,4·10-6s = 6,4·10-5m, that is, it will not pass the path equal to half the thickness of the wire mesh, and will be discarded. Even if the suspension will have a size smaller than one micron, the grid will be for her an insurmountable obstacle. To go inside the grid, suspension should increase the component of velocity normal to the direction of the velocity grid.

Take the speed of the suspension is equal to 40 m/sec. Being at the initial moment at the front in the direction of wire mesh cell, it will move on the 40 m/s × 6,4·10-6=2,56·10-4m, that is, a suspension will be held in the cavity of the grid, and for her passage width is substantially less than the width of the window of the cell in the grid, making the grid separare suspended in size. The size of the molecules, as a rule, do not exceed 5·10-10m, and the speed can reach hundreds of m/s. For them, the grid will not pose significant obstacles.

Table 1
ComponentMol µVol. %ρ, g/ltCrete, °CpCrete, at.ρCrete, g/cm3
1. Xenon2Heh131,308·10-65,8589916,5960,161,105
2. Krypton3Kr83,8011·10-53,74-63,855,90,908
3. Bhutan4With4H1058,522,73204152,0137,470,228
4. Isobutane58,522,73204134,9836,000,221
5. Ozone5About347,99822·10-62,1418-1254,60,54
6. Carbon dioxide6CO244,10793,3·10-21,977 31,0to 75.20,468
7. Propane744,0681,966496,842,00,220
8. Argon Ar39,9480,9341,783-122,4349,6mean HDI of 0.531
9. Oxygen8O231,996820,951,429-118,8449,710,41
10. Ethan930,0681,34232,2748,30,203
11. Ethylene10to 28.051,26039,5050,650,227
12. Nitrogen11N228,013478,09 -147,033,50,311
13. Carbon monoxide12CO28,010551,25-140,234,60,301
14. Neon13Ne20,1831.6 x 10-30,9004-228,627,750,484
15. Water is H2O (pairs)18,015340,484 (0,80)14374,2218,50,32
16. Methane15CH416,043030,7159-82,545,8rate £ 0.162
17. Helium is Not4,00264,6·10-40,1785-268°of 2.260,0693
18. Hydrogen 2,015945·10-50,08988-24012,80,031
2The atomic radius of 2.18 Å, obtained from air, used in vacuum technology and fluorescent lamps.
3The atomic radius of 1.98 Å, obtained from air, used in vacuum technology for filling lamps, thyratrons, advertising tubes (pure white light).
4Mixtures with air containing 1.5 to 8.5% of Bhutan [CH3(CH2)2CH3] or 1.8-8.4% of isobutane [(CH3)2CH2CH2] explosive. Butane contained in natural gas. The average content of ethane, butane and propane in the composition of coal gas ranges from 1 to 10%, increasing individual samples up to 15-20%. These gases occur in rocks from depths of 10-20 m
5Very toxic concentration of 10-5% can cause headaches, irritation of the respiratory tract and eyes, the use of ozone due to its oxidizing disinfectant and bactericidal action.
6When the content in the air more than 4% causes respiratory tract irritation, tinnitus, dizziness, headache. There is a selection of rocks.
7Ignition temperature 465°C; limits vzryvaem and in mixtures with air 2,1-9,5%vol.; at a pressure of 1 ATM and 0°C decomposes.
8On receipt of 1 nm399%of the oxygen is consumed not less than 0.5 kW·h of electricity. Oxygen forms compounds with all chemical elements except the inert gases. The speed of oxidation reactions increases with increasing temperature. A special role as a catalyst plays water. The flame of carbon monoxide, burning in wet oxygen at the introduction into the atmosphere of dry oxygen immediately goes out.
9The limits of explosive with air 3,22-12,45%; derived from oil and natural gas, where it contains 5-10%; and has a weak narcotic effect.
10The limits of explosive with air 3-34 vol.%; in medicine ethylene is used for General anesthesia in surgical interventions; contained in natural gas.
11On receipt of 1 nm3nitrogen is consumed 0.25 kW·h of electricity.
12Flammability limits in a mixture with air of 12.5-74%. Rocks, particularly coal, sometimes include significant quantities of carbon monoxide, causing them to "spontaneous combustion" in the showdown.
13The atomic radius of 1.6 Å, obtained from the air used to fill the cheap incandescent bulbs, and fluorescent lights (red glow), under vacuum.
14In parentheses indicate the density of 1 mole of steam in the void.
15The limits of the ot is weemote from 5 to 15%. At lower concentrations support combustion, when large - lit. Ignites when 695-742°C. is Used as fuel and as raw material for Promsintez.

2,1418
Table 216
Componentρ kg/m3r=0.5 mr=0.4 mr=0.3 mr=0.2 m
1. Xenon Xe5,85899289129,4231303,5173477,6115651,8
2. Krypton Kr3,74184561,5147649,2110736,973824,6
3. Bhutan4H102,73204134820,7107856,680892,453928,3
4. Isobutane2,73204134820,7107856,680892,453928,3
5. Ozone O3105693,584554,863416,142277,4
6. Carbon dioxide CO21,97797561,078048,858536,639024,4
7. Propane1,966497037,977630,358222,738815,2
8. Argon Ar1,78387987,570390,052792,535195,0
9. Oxygen O21,42970518,356414,642311,028207,3
10. Ethan1,34266225,052980,039735,026490,0
11. Ethylene1,260362193,349754,637316,024877,3
12. Nitrogen (N21,25161734,349387,437040,624693,7
13. Carbon monoxide CO1,2561685,049348,037011,024674,0
14. Neon Ne0,900444433,035546,426659,817773,2
15. Water is H2O (pairs)0,484 (0,80)23884,419107,514330,69553,8
16. Methane CH40,715935328,228262,621196,914131,3
17. Helium is Not0,17858808,67046,95285,23523,4
18. Hydrogen H20,089884435,43548,3 2661,21774,2
16Table 2 shows the differentiation achieved by the application of the proposed methods and devices. Notes supplemented by information about the radioactive gas radon. It is:
1) the Fourth and subsequent columns of the table, judging by the dimensions presented values are the pressure gradient in the cavities of compressor blades that exceed those in the gravitational field of the Earth. In particular, sea level pressure falls approximately 12 PA with increasing height of 1 m, which is approximately 5000 times smaller than the gradient of ethylene at a distance of 0.5 m from the axis of rotation at 3000 rpm/min
2) Known gases present in the atmosphere, differentiated by density. So the density of the heavy xenon gas equal 5,85899 kg/m3the most easy - hydrogen - 0,08988 kg/m3i.e. the ratio of their densities is approximately equal to 65. This natural phenomenon. The use of centrifugal radial-flow compressor, as can be seen from the table that allows to increase this differentiation. To be sure, divide the pressure gradient xenon from the 4th column on the pressure gradient of the hydrogen 7-th column. 289129,4/1774,2=163, i.e. produced increased 2.5 times.
3) In the composition of the atmosphere of the Earth is a radioactive gas radon. Known 19 isotopes of radons mass numbers 204 and 206-224. The most long-lived isotope with mass number 222 has a half-life 3,8229 days. 1 m3air under normal conditions contains 7·10-6g radon. On cold surfaces radon is easily condensed to a colorless phosphorescent liquid. Despite its chemical inertness, radon is one of the most toxic and dangerous poisons, due to its radioactivity. Radon is widely used in medicine (radon baths) and when looking at the nature of radioactive elements. Known methods of obtaining and purification of radon based on the linkage of associated gas, after which the radon frozen in liquid nitrogen, and helium and hydrogen is pumped out. To obtain 1 mol of radon during the mechanical separation must pass through the separator about 222/7·10-6=31714286 nm3air. When the performance of the separator through the air 10 nm3/s, this result is achieved through 36.7 days of operation of the separator. This gas has unique properties, and therefore is a valuable by-product of mechanical separation.

1. The method of conditioning air in mine development, in which the separator is placed in the cavity output, characterized in that the conditioning of conduct in respect of hydrocarbons, which are output by the pipeline and replace all of the volume at oferim air.

2. The separator gas in coal seams, comprising a housing with connections to input and exhaust gases, engine, radial-flow centrifugal and centripetal compressors, impellers, blades which rotate around the axis of the hollow propeller, characterized in that the blades of the impeller of the centrifugal radial-axial compressor performs hollow and provided with slots in the front and rear surfaces, the slots extend from the propulsion to the toroidal cavity of the compressor, the ends of the blades choke, caps perform radially oriented channels, the input and output gases in the cavity of the rotation of the impeller leading through the plate lattice in the form of a circular ring width from the edges of the donut to surface propulsion, not touching her, the surface of the radial and circular plates grids set at an acute angle to the axis of rotation, a propeller secured on the tubular extension of the motor shaft to the inner surface of the thruster fixed blade radial-flow centrifugal compressor, a tubular extension of the motor shaft sochinyayut to the housing of the separator by means of two bearings, his oral report with a cavity propulsion and pipe outlet is relatively light components, a relatively heavy components are selected through a pipe, which is cut in the most remote from the axis of rotation is the place doughnut.

3. Mine cage with a grid that includes a radial-flow centrifugal and centripetal compressors, propulsion, engine and valve, characterized in that it contains from two to eight centrifugal and two centripetal radial-flow compressor, which are arranged in one unit; the blades of the impellers all compressors mounted on a common vehicle; input cavity from top to secure the umbrella in which secure the pipe with flange removal of light gases, and a perimeter enclosing bars connecting the umbrella with the donut upper radial-flow centrifugal compressor; the blades of the input radial-flow centrifugal compressor smoothly curved from all prior circular plate lattice; on the input ends of the blades of the compressor are fixed fine mesh in the form of a circular cylinder.



 

Same patents:

FIELD: mining.

SUBSTANCE: previously frame is prepared for heating with the help of flexible heating element, which is arranged along perimetre of outer or inner surface of frame with fixation on it. Afterwards heating element via terminal box arranged inside connecting box is connected to sensor for control of air temperature supplied to area of frame location. Sensor is connected to source of power supply. Area of sensor location together with connecting box is a section of frame, towards which largest part of cold atmospheric air flow is directed in process of reverse. Under conditions of negative temperatures, prior to reversing of ventilation jet at specified time by actuation of air temperature control sensor, heating element is connected to source of power supply, providing for preheating of supply channel folding door frame. As ventilation jet is reversed with supply of cold atmospheric air, channel folding door is transferred to position of reverse mode with the possibility of adjacency to heated frame. At the same time frame heating is continued, and heat is transferred from frame to folding door, preventing its icing. As time of ventilation jet reversing elapses, frame heating is stopped by de-energising of heating element. Then since channel folding door will not freeze to frame, it is freely changed into initial position. Prevents icing of folding door in supply channel during ventilation jet reversing under conditions of negative temperatures.

EFFECT: heating of supply channel folding door as it adjoins heated frame in reverse mode position.

6 cl, 4 dwg

FIELD: mining.

SUBSTANCE: invention refers to the sphere of mining industry and may be used in mines ventilation. Method for automatic regulation of temperature of air supplied in mine includes application of geothermal heat of mine pumping water, at the same time pipe of pumping with radiators for increase of heat exchange area between water and air is pulled through surface tunnel with length of 30-50 m, arranged in front of heater, moreover, pipe is arranged with at least two turns and is installed with a permanent inclination of at least 0.02 along with water flow.

EFFECT: method makes it possible to considerably save thermal energy in winter and to cool hot air down in summer.

2 dwg

FIELD: oil-and-gas production.

SUBSTANCE: providing of stability of well walls, process controllability of opening of waterbearing formation of operation of two waterbearing formations of one upward drain borehole has become possible ensured by creation of backpressure in annular space of well during all time of its drilling in incompetent rocks and also usage in particular case in the capacity of intermediate string of filtering pipe string. Device for opening of waterbearing stratums in incompetent rocks by upward drain borehole includes drilling rig, rotator, main mud pump, drilling assembly, intermediate string, filtering pipe string and equipment of wellhead, containing conductor, wellhead mandrel, pipes grab, gland, closing sleeve, outlet and shutter. Intermediate string is outfitted by ring, rigidly installed to it at bottom end with ability of installation of sealing ring for overlapping of annular gap between conductor and intermediate string. Device is outfitted by additional boring pump, connected to outlet of wellhead mandrel, and also by nozzle installed at outlet of this branch diametre of which depends on static level of waterbearing formations at wellhead and rotary crane for passing of water into outlet from additional drilling pump.

EFFECT: providing of ability of additional water removing.

3 cl, 4 dwg, 2 ex

Stowing mixture // 2386035

FIELD: oil-and-gas production.

SUBSTANCE: stowing mixture contains, wt %: halite wastes of reprocessing of potassic ores 96.5-98.3, bonding agent - magnesia cement 1-2, lignosulfonate 0.7-1.5%.

EFFECT: achievement of required strength of backfilling at minimal content of bonding agent.

1 tbl, 1 dwg

FIELD: heating.

SUBSTANCE: method involves heating of ambient air with flue gases coming from fuel combustion chamber, its supply to the mine through ventilation system. Hot air addition is dosed to ventilated air flow directly to suction channel of the main mine ventilation fan. Secondary blasting is used in combustion chamber. Secondary air is heated in convection jacket of side walls of combustion chamber. In outlet gas duct there used is cold air blast which is directed upwards at an angle not less than 45°. Fuel combustion chamber is equipped with outside located secondary air fans and inclined slit atomisers provided in side walls. External surface of side walls of fuel combustion chamber is equipped with convection jacket. Gas burners are located in ceiling part of fuel combustion chamber. Mine air heating is improved by preventing flue gas penetration into ventilation flow supplied to the mine.

EFFECT: increasing air-heating plant efficiency owing to complete fuel combustion, decreasing metal consumption of air pipeline.

4 cl, 3 dwg

FIELD: mining.

SUBSTANCE: invention refers to mining industry, and namely to the method used for hydraulic filling of long single mine workings. It involves influence of retaining and filtering connection straps, installation of pulp pipeline, and supply of filling pulp. Water is drained via drain holes made in connection straps installed on the side opposite to the pulp supply. Filling pulp is supplied to the filled area via pulp pipeline with the holes made in lower part, which is attached to the roof of mine working throughout its length. The holes made at the beginning of the pipeline are equipped with petal valves.

EFFECT: increases the filling degree of the worked-out area in hard-to-reach sections.

2 cl, 2 dwg

FIELD: mining.

SUBSTANCE: invention is related to mining industry, namely to method for preparation of stowing mix. Tails of dressing works are sent to several stowing complexes with application of hydraulic transport system, comprising working and drain branches. Tails are separated in each stowing complex into condensed product sent for preparation of stowing mix and lightened discharge. Working and drain branches of hydraulic transport system are separated. Tails from working branch are sent to each stowing complex, and lightened discharge is drained to drain branch. End part of working branch and beginning of drain branch in hydraulic transport system are joined by emergency bridge comprising stop valves. Each stowing complex newly added to system of hydraulic transport is duplicated with emergency bridge. System of hydraulic transport includes several separated working and drain branches, which service groups of stowing complexes that vary in number. Working and drain branches of hydraulic transport system for sending of tails to several groups of stowing complexes may be combined into headers.

EFFECT: provision of stable high quality of mines stowing, increased efficiency and safety of mining works, lower costs for preparation of stowing mix and transportation of dressing works tails in servicing of several mines.

7 cl, 8 dwg, 1 ex

FIELD: mining.

SUBSTANCE: invention is related to mining industry, namely to charging devices for belt conveyors, intended for transportation of large-sized materials. Rotary-vane feeder of conveyor comprises drum, which consists of two rims joined to each other by means of radial blades, support rollers and tray, which are installed on frame. Besides support rollers are installed in pairs on balancing levers, which are hingedly joined to frame. Radial blades are equipped with breaking beams, which are arranged over blades and are connected to them by means of elastic elements.

EFFECT: increased reliability and durability due to reduction of contact tensions between rims and rollers and reduction of dynamic impact loads at blades.

3 dwg

FIELD: mining.

SUBSTANCE: invention refers to mining engineering and can be used during underground development of mineral deposits. Erection method of filling connection strap involves making of rock dike by laying as to width and height of the filling working of large rock pieces 1, on which there put is layer of finer rock or sand 2 with drain pipe 3 passed through rock dike. On rock dike there installed are pneumocylinders 4, which are forced outwards, between rock dike and roof of working by supplying to pneumocylinders 4 of compressed air with outward pressure which is more than limit value, at decrease of which pneumocylinders 4 are forced with backfill material 5 to the side of non-filled part of the working. Distance between rock dike and roof of working is determined by the ratio: amin<h<0.75amax, where: amin - minimum height of pneumocylinder 4 when in folded position till compressed air is supplied to it; h - distance between rock dike and roof of working; amax - size of pneumocylinder 4 after compressed air has been supplied to it.

EFFECT: increasing efficiency of filling operations.

1 cl, 1 dwg

FIELD: mining.

SUBSTANCE: invention refers to mining engineering and can be used during underground development of mineral deposits. Erection method of filling connection strap involves making of rock dike by laying as to width and height of the filling working of large rock pieces 1, on which there put is layer of finer rock or sand 2 with drain pipe 3 passed through rock dike. On rock dike there installed are pneumocylinders 4, which are forced outwards, between rock dike and roof of working by supplying to pneumocylinders 4 of compressed air with outward pressure which is more than limit value, at decrease of which pneumocylinders 4 are forced with backfill material 5 to the side of non-filled part of the working. Distance between rock dike and roof of working is determined by the ratio: amin<h<0.75amax, where: amin - minimum height of pneumocylinder 4 when in folded position till compressed air is supplied to it; h - distance between rock dike and roof of working; amax - size of pneumocylinder 4 after compressed air has been supplied to it.

EFFECT: increasing efficiency of filling operations.

1 cl, 1 dwg

FIELD: process engineering.

SUBSTANCE: invention relates to catalytic filtration of diesel soot. Catalytic filter for diesel soot comprises filter element coated by catalytic agent to allow diesel soot to settle in contact with catalytic agent when diesel engine exhaust comes through porous filter element modified as follows: catalytic agent comprising alkaline metal, cerium and oxygen with molar ration of alkaline metal to cerium makes, in the case of catalytic agent, varies from 0.5 to 5. Method of reducing ignition temperature or diesel soot oxidation temperature comprises the stage of bringing exhaust gas in contact with catalytic agent. Catalyst comprises catalytic agent that includes alkaline metal, cerium and oxygen with molar ration of alkaline metal to cerium for catalytic agent varies from 0.5 to 5.

EFFECT: reduced ignition or diesel soot oxidation temperature.

25 cl, 5 dwg, 1 tbl, 4 ex

FIELD: process engineering.

SUBSTANCE: invention relates to CO2-extraction device and method of fast removal of depleted material from regenerator that forms in the device. Proposed device comprises absorption column, regeneration column, condenser and refrigerator. Absorption column CO2-containing gas and CO2-absorbing solution are brought into contact to produce solution enriched by CO2. The latter is fed into regeneration column wherein weak solution results due to removal of CO2 from enriched solution. Fraction of weak solution comes via offtake line into regenerator. Weak solution is heated in regenerator to produced condensed wastes and evaporated solution that absorbs CO2. Condensed wastes from generator are fed into refrigerator and cooled to or below 50°C. Solution absorbing CO2 recovered in regenerator is fed into regeneration column.

EFFECT: reduced weak material cooling time, simplified process.

6 cl, 3 dwg

FIELD: process engineering.

SUBSTANCE: invention relates to CO2-extraction device and method of fast removal of depleted material from regenerator that forms in the device. Proposed device comprises absorption column, regeneration column, condenser and refrigerator. Absorption column CO2-containing gas and CO2-absorbing solution are brought into contact to produce solution enriched by CO2. The latter is fed into regeneration column wherein weak solution results due to removal of CO2 from enriched solution. Fraction of weak solution comes via offtake line into regenerator. Weak solution is heated in regenerator to produced condensed wastes and evaporated solution that absorbs CO2. Condensed wastes from generator are fed into refrigerator and cooled to or below 50°C. Solution absorbing CO2 recovered in regenerator is fed into regeneration column.

EFFECT: reduced weak material cooling time, simplified process.

6 cl, 3 dwg

FIELD: process engineering.

SUBSTANCE: invention relates can be used in metallurgy, electronics and in production of pigments and welding electrodes. Wastes of production of ferrous alloys containing, mainly, manganese represent slimes of fume gases washing from furnaces producing ferromanganese and silicon manganese. Said wastes are directed for thermal sulphating 1 that comprises furnace processing of material fed from mixer wherein said wastes have been subjected to treatment by acid with flow rate approximating to stoichiometric. Teflon chutes are used inside the furnace to produce SO2. Then hydrometallurgical phase is performed consisting of vatting stage 2, primary 3 and secondary 4 washing stages and that of conditioning. Vatting is carried out at intensive mixing in reactor with coating that regulates acidity using anolyte of electolyser or synthetic anolyte. Primary washing stage 3 is carried out in the same reactor till pH increases to values approximating to neutral one by removing, mainly, iron and aluminium. Produced fine pulp is filtered in pressure filter, flushed by water, preferably, in the same pressure filter, to produce inert wastes. Fine pulp flushing water is added into the mixer or used again to concentrate manganese therein. At secondary flushing stage 4, zinc impurity is removed by settling ZnS. Solution obtained after conditioning 5, is directed to electrolysis 6 to produce electrolytic manganese.

EFFECT: possibility to recover wastes to produce 99,9%-pure manganese.

5 cl, 6 dwg

FIELD: process engineering.

SUBSTANCE: invention relates can be used in metallurgy, electronics and in production of pigments and welding electrodes. Wastes of production of ferrous alloys containing, mainly, manganese represent slimes of fume gases washing from furnaces producing ferromanganese and silicon manganese. Said wastes are directed for thermal sulphating 1 that comprises furnace processing of material fed from mixer wherein said wastes have been subjected to treatment by acid with flow rate approximating to stoichiometric. Teflon chutes are used inside the furnace to produce SO2. Then hydrometallurgical phase is performed consisting of vatting stage 2, primary 3 and secondary 4 washing stages and that of conditioning. Vatting is carried out at intensive mixing in reactor with coating that regulates acidity using anolyte of electolyser or synthetic anolyte. Primary washing stage 3 is carried out in the same reactor till pH increases to values approximating to neutral one by removing, mainly, iron and aluminium. Produced fine pulp is filtered in pressure filter, flushed by water, preferably, in the same pressure filter, to produce inert wastes. Fine pulp flushing water is added into the mixer or used again to concentrate manganese therein. At secondary flushing stage 4, zinc impurity is removed by settling ZnS. Solution obtained after conditioning 5, is directed to electrolysis 6 to produce electrolytic manganese.

EFFECT: possibility to recover wastes to produce 99,9%-pure manganese.

5 cl, 6 dwg

FIELD: process engineering.

SUBSTANCE: invention relates can be used in metallurgy, electronics and in production of pigments and welding electrodes. Wastes of production of ferrous alloys containing, mainly, manganese represent slimes of fume gases washing from furnaces producing ferromanganese and silicon manganese. Said wastes are directed for thermal sulphating 1 that comprises furnace processing of material fed from mixer wherein said wastes have been subjected to treatment by acid with flow rate approximating to stoichiometric. Teflon chutes are used inside the furnace to produce SO2. Then hydrometallurgical phase is performed consisting of vatting stage 2, primary 3 and secondary 4 washing stages and that of conditioning. Vatting is carried out at intensive mixing in reactor with coating that regulates acidity using anolyte of electolyser or synthetic anolyte. Primary washing stage 3 is carried out in the same reactor till pH increases to values approximating to neutral one by removing, mainly, iron and aluminium. Produced fine pulp is filtered in pressure filter, flushed by water, preferably, in the same pressure filter, to produce inert wastes. Fine pulp flushing water is added into the mixer or used again to concentrate manganese therein. At secondary flushing stage 4, zinc impurity is removed by settling ZnS. Solution obtained after conditioning 5, is directed to electrolysis 6 to produce electrolytic manganese.

EFFECT: possibility to recover wastes to produce 99,9%-pure manganese.

5 cl, 6 dwg

FIELD: process engineering.

SUBSTANCE: invention relates to production of catalysts applied onto porous oxide carriers for detoxication of exhaust gases. In compliance with one version, proposed method consists in that oxide carriers or their mixes with zeolites are treated by aqueous solutions of acetic acid with concentration varying from 15% to 98% by volume, dried and impregnated with aqueous solutions of noble metal nitrates. In compliance with second version, proposed method comprises impregnation of oxide carriers with aqueous solutions of noble metal nitrates. Note here that acetic acid is incorporated into impregnation solutions. In compliance with third version, wet applied catalysts can be processed into coat dispersion without preliminary roasting. Coat is then applied onto one-piece cellular element to be dried and roasted in airflow. Produced catalysts are used detoxication of automotive exhaust gases and those from stationary industrial plants.

EFFECT: production of catalysts containing mixed metal oxide particles of noble metals with adjustable grain size.

18 cl, 11 ex, 2 tbl

FIELD: process engineering.

SUBSTANCE: proposed invention relates to chemical and petrochemical industries. Acid gas flow containing carbon sulphide as initial material is fed into combustion stage in the presence of oxygen. Oxidising conditions are selected so that carbon sulphide-to-sulfur dioxide exceeds 2:1. Combustion products flow is directed to catalytic stage of Klaus reaction which results in reaction gas containing sulfur to be extracted therefrom. End gas containing less than 1000 ppmv of sulfur dioxide is fed into biological system of gas desulfuration. Said biological system allows producing sulfur and neutral gas containing less than 100 ppmv of carbon hydrogen.

EFFECT: reduced content of sulfur dioxide in Klaus process end gases, hence, reduced consumption of alkali and lower operating costs.

17 cl, 2 dwg, 1 tbl, 1 ex

FIELD: process engineering.

SUBSTANCE: proposed invention relates to chemical and petrochemical industries. Acid gas flow containing carbon sulphide as initial material is fed into combustion stage in the presence of oxygen. Oxidising conditions are selected so that carbon sulphide-to-sulfur dioxide exceeds 2:1. Combustion products flow is directed to catalytic stage of Klaus reaction which results in reaction gas containing sulfur to be extracted therefrom. End gas containing less than 1000 ppmv of sulfur dioxide is fed into biological system of gas desulfuration. Said biological system allows producing sulfur and neutral gas containing less than 100 ppmv of carbon hydrogen.

EFFECT: reduced content of sulfur dioxide in Klaus process end gases, hence, reduced consumption of alkali and lower operating costs.

17 cl, 2 dwg, 1 tbl, 1 ex

FIELD: process engineering.

SUBSTANCE: invention is intended for cleaning flue gases of harmful admixtures. Proposed method comprises mixing flue gases with ozone-air mix and oxidising nitrogen oxide (NO) to nitrogen dioxide (NO2) in pre-oxidising chamber, feeding acid condensate for cleaning of acid components into heat recovery unit first chamber operated in cold conditions, separating solution of hydrogen nitrate solution (HNO3·3H2O) and forcing it in hydrogen nitrate storage tank. It comprises also adding hot air flow to blow air prior to feeding it into processing zone for cooling flue gases, parallel feed of purified flue gases into heat recovery unit second chamber wherein stepwise ice defrosting occurs during regeneration by purified flue gases that are forced from heat recovery unit into atmosphere. Finally, cold air is directed into second chamber, while purified flue gases are directed in first chamber to repeat abode described cycle. Proposed device comprises processing zone including the chamber of pre-oxidising with distributor of ozone-air mix, heat exchange-condensation and absorption-condensation sections with separate trays, pump, heat recovery unit consisting of two identical chambers with trays wherein inclined slot-like shelves are staggered.

EFFECT: higher efficiency of flue gas cleaning of nitrogen oxides.

2 dwg

FIELD: gas treatment.

SUBSTANCE: invention relates to adsorption separation of gases and provides carbon dioxide absorbent, which is prepared by impregnating porous alumina with potassium carbonate, alumina having been preliminarily treated with alkali solution, in particular solution of alkali metal hydroxides and/or carbonates. Alkali treatment is carried out at temperature above 40оС. Method of removing carbon dioxide from gas mixture, including adsorption separation of carbon dioxide from atmospheric air in cyclic processes under thermal regeneration or short-cycle heating-free adsorption conditions, is characterized by that process is conducted at 20 to 200оС with above indicated absorber.

EFFECT: increased dynamic capacity of absorber and increased carbon dioxide absorption velocity.

5 cl, 2 dwg, 9 ex

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