Method to predict disposition of mineral coals to self-ignition and device for its realisation
SUBSTANCE: to predict disposition of mineral coals to self-ignition, a model is created, which imitates natural processes of hydrothermall and fluidogenic conversion of coals in foci of self-ignition of pit beds. Continuous flow filtration of air and water mix is carried out via a ground coal sample, placed into a quartz reactor with the specified heating mode to temperature not exceeding temperature of coal self-ignition. Then the quartz reactor is cooled down to room temperature, and continuous flow filtration is repeated. The start of sample thermal destruction is fixed by reaction of indicator gas with water-alkaline solution. By the angle of opening of curves corresponding to the first and repeated heating in the chart they determine speed of exothermic reaction behaviour. The time for incubation period of self-ignition is calculated, which is a predictive factor of disposition of mineral coals to self-ignition.
EFFECT: development of a model that imitates natural processes of low temperature hydrothermal and fluidogenic conversion of coals in foci of self-ignition of pit beds.
10 cl, 5 dwg
The invention relates to the field of research materials by determining their thermal properties and is designed to predict the endogenous risk of fire coal shahtoplastov exploration developments.
Chemical and physical changes of coal caused by oxidation, accompanied by evolution of heat, which accumulates due to their poor thermal conductivity. The result is a spontaneous combustion of coal mines, stockpiles, storage in dumps, which creates difficulties in providing security, complicates the environment and leads to a significant loss of raw materials, to injuries. Prone to spontaneous combustion of the coal at all stages of metamorphism, but most tend brown and black.
From the prior art known methods for evaluation of spontaneous combustion of coal, based on measurement of the concentration of indicator gas in the sample mine air (EN 2459959 C1, E21F 5/00, publ. 27.08.2112) , (EN 2271450 C2, E21F 5/00, publ. 10.03.2006) . All known patented methods for evaluation of spontaneous combustion of coal is used directly in the mine workings on the fact of occurrence of endogenous fire and do not solve the task of predicting the propensity of coals to spontaneous combustion in exploration development shahtoplastov.
According to the laboratory method of estimating the propensity Shah is plastow of coal to spontaneous combustion, decl. By order of the Ministry of energy of the Russian Federation from 29.04.1998 No. 151 determine the chemical activity of the speed of sorption of carbon oxygen in the sorption vessel. Apparatus for assessing the activity of coal contains the sorption vessel made of glass with a thickness of 2-3 mm, with two cranes: overhead crane, which is a glass tube with soldered in her tube, which are polished to the throat of the vessel, the bottom of the vacuum valve, three-way. The vessel is fixed on a tripod. At the bottom of the vessel are poured layer of glass rods. The device must be sealed, cranes, well polished, greased with vacuum grease and tested, as a result of adsorption of oxygen by coal in the vessel creates a vacuum. Selected in the mine sample is delivered to a cut, crushed, sieved on a sieve with a selection of narrow fractions 1-3 mm (more than one, less than three mm) and immediately tested. Storage of samples is permitted only in hermetically sealed glass vessels.
Determined by the method of chemical reactivity of coals is important, but insufficient factor in the prediction of endogenous fire risk. The possibility of spontaneous combustion of coal is determined not only by chemical activity, but also the external conditions in which there is accumulation of debris.
The closest to the technical nature of the claimed image is ateneu is a method of detection of spontaneous combustion of coal , includes measuring trace gas at the outlet of accumulations of coal and rock, taken as a prototype of the present invention.
The prototype method is not possible in the laboratory to predict the propensity of coals to spontaneous combustion to obtain conclusions about the endogenous risk of fire coal shahtoplastov in preparing the field for commercial development.
The present invention is to develop a laboratory method for predicting the propensity of coals to spontaneous combustion when preparing deposits for commercial development.
The problem is solved with the new achievement of the technical result - the creation of models that simulate natural processes of low-temperature hydrothermal and fluidising conversion of coals in the foci of spontaneous combustion shahtoplastov through the implementation of continuous flow water filter-air mixture through the crushed sample of coal, placed in a quartz reactor with a given mode of heating.
This technical result is achieved in that a method for predicting the propensity of coals to spontaneous combustion enables measurement of the concentration of indicator gas in the test sample. According to the invention create a model that simulates the natural processes of hydrothermal and fluidyn the CSOs conversion of coals in the foci of spontaneous combustion shahtoplastov by continuous flow filtration water-air mixture through the crushed sample of coal, placed in a quartz reactor with a given mode of heating, thus a continuous flow filtration of water-air mixture is carried out in the temperature range of 25-100°C for brown coal, 25-150°C for coal, 25-250°C for anthracite coal, then cooled quartz reactor to room temperature and repeat continuous flow filtration of water-air mixture at the specified temperature ranges and record the beginning of thermal decomposition of the sample (ito) by the reaction of the tracer gas with an aqueous-alkaline solution and
- angle of divergence of the curves corresponding to the first and re-heated on the graph according to T°C=f(t) determine the rate of exothermic reaction V by the formula V=δT/t°C/min, then
- calculate the incubation period τ of spontaneous combustion of coal by the formula τ=TCB - UTR/V min, which is a prognostic factor in the propensity of coals to spontaneous combustion.
In some cases, of the complete method:
as the aqueous alkaline solution using calcium hydroxide;
- continuous flow filtration of water-air mixture through the quartz reactor is performed by the suction pump performance 0.2-1 l/min
A method for predicting the propensity of coals to spontaneous combustion is carried out by the device according to the invention contains a quartz reactor in the form of rotunno pipe to accommodate samples of coal, automatic suction pump with rotameter, water-alkaline bubbler made of transparent glass, removable heater covering the quartz reactor at its input connected to the block temperature control, while a quartz reactor with inlet and outlet fittings, which are fitted with air filters made of glass wool, the ends of the quartz reactor equipped with sealed plugs through the two holes in the tube, located at the exit of the quartz reactor skipped electrodes, the outputs of which are connected to the temperature logger, quartz reactor through an outlet fitting connected with an aqueous-alkaline bubbler flexible hose on the end of which a spray of air, immersed in an aqueous-alkaline solution, and an aqueous-alkaline bubbler through the nozzle is connected by a flexible hose with a rotameter aspirator.
In special cases the device run:
- the volume of the quartz reactor is 150 cm3;
the rotameter has a capacity of 0.2 to 1 l/min;
- the volume of the bubbler is 0.5 l;
air filters are made of glass wool;
- electrodes thermocouples made of chromel-alumel;
as the aqueous alkaline solution in Barbulators used calcium hydroxide CA(Oh)2.
When heated coal to 100°C at the inlet of the quartz reactor is formed n novastoshnah mixture, which extends to the exit of the quartz reactor, thereby activating a sample of coal, which loses up to 80% moisture. When re-heating after cooling the quartz reactor is an increase in chemical (sorption) activity and decrease the initial temperature of accidentally (utrs) of the sample which leads to the acceleration of spontaneous combustion of coal and is a simulation model of the complex processes of spontaneous combustion of coal by hydrothermal fluidization shahtoplastov.
The invention is illustrated by figures of the drawings.
Figure 1 shows a schematic drawing of an apparatus for implementing the method for predicting the propensity of coals to spontaneous combustion.
Figure 2 shows graphs of concentration WithCO2, mW/mg values of the ion current DTA, 10-10And the mass loss of the sample TG,% from the heating temperature T°C, obtained on the instrument STA S for not oxidized lignite, where TG is a thermogravimetric curve, the DTA curve of differential thermal analysis, WithCO2- curve of a synchronous allocation of CO2, STS - initial temperature of accidentally coal, TCB - temperature spontaneous combustion of coal.
Figure 3 shows graphs of concentration WithCO2, mW/mg, the mass loss of the sample TG,% and ion current DTA, 10-10And from the heating temperature T°C, obtained on the instrument STA S for oxidized brown coal, STS - initial temperature of accidentally coal, TCB - temperature spontaneous combustion of coal.
Figure 4 shows comparative graphs of the dependencies changes in the temperature of the sample, T°C is not oxidized brown coal at the outlet of the reactor from time blowing coal air, min, with 2-fold heating the reactor to a temperature not exceeding the initial temperature of accidentally coal, where curve 1 corresponds to the first cycle of heating and curve 2 - re-cycle heating conducted after cooling the reactor to room temperature, T1the point of intersection of curves 1 and 2, the angle α is their difference, δt is the temperature change in the first and second cycle of heating samples of coal.
Figure 5 shows comparative graphs of the dependencies changes in the temperature of the sample, T°C oxidized brown coal at the outlet of the reactor from time blowing coal air, min, with 2-fold heating the reactor to a temperature not exceeding the initial temperature of accidentally coal, where curve 1 corresponds to the first cycle of heating and curve 2 - re-cycle heating conducted after cooling the reactor to room temperature, T1the point of intersection of curves 1 and 2, the angle α is their difference, δt is the temperature change in the first and second cycle of heating samples of coal.
A device for predicting the propensity of a lawsuit the activity of coals to spontaneous combustion (figure 1) contains a quartz reactor 1 in the form of tubes with a volume of 150 cm 3to accommodate samples of coal, automatic aspirator 2 stamps AR-4, water-alkaline bubbler 3 a volume of 0.5 liters, made of transparent glass, removable heater 4, covering the quartz reactor 1 at its input connected to the block temperature control 5. Quartz reactor 1 has an inlet port 6 and outlet fitting 7, which is installed filters 8 and 9, respectively, are made of glass wool. The ends of the quartz reactor 1 is equipped with sealed tubes 10, 11. Through two holes in the tube 10 missed electrodes chromel-alyuminievoi tertiary 12, the outputs of which are connected to the temperature logger 13. Quartz reactor 1 through an outlet nozzle 7 is connected with an aqueous-alkaline Barbarum 3 flexible hose 14, the end of which a spray of air 15, immersed in an aqueous solution of CA(Oh)2. Output water-alkaline bubbler 3 through the fitting 16 is connected by a flexible hose 17 with the flowmeter 18 automatic aspirator 2 performance 0,-1 l/min
In a quartz reactor 1 is installed tube 10 with thermocouple 12, load it with a sample of crushed coal weighing 150-200 g and close the airtight tube 11. The output nozzle 7 through a flexible hose 14 is connected with an aqueous-alkaline bubbler 3, the fitting 16 which through a flexible hose 17 is connected flowmeter 18 performance 0.2-1 l/min automatic Asper the Torah 2. At the entrance of the quartz reactor 1 is installed removable thermopatch 4. In block temperature control 5 specify one of three modes of heating the quartz reactor 1 for the studied brands of coals: 25-100°C for brown coal, 25-150°C for coal, 25-250°C for anthracite coal, which is caused by difference for initial temperatures of accidentally (ito).
Due to the vacuum generated by the automatic aspirator 2, the air through the inlet port 6 and the filter 8 with a speed of 0.5-1 l/min is supplied in a quartz reactor 1 is filled with crushed coal fraction 0,16-0,5 mm When heated quartz reactor 1 in the specified mode 25-100°C for brown coal sample, placed in it, is activated by loss of up to 80% moisture for 70 minutes Then thermopatch 4 off and kept quartz reactor 1 for 24 hours at room temperature to cool the sample.
Dried thus a sample of coal is subjected to repeated heating mode of the first cycle, which leads to increased binding of oxygen mainly due to the formation of radicals, carboxyl and hydroxyl groups and heating the sample due to the exothermic oxidation reactions contained combustible components. The oxidation of coal is accompanied by the release of CO2that is, entering into a chemical reaction with an aqueous solution of CA(Oh)2,about the will formed an insoluble precipitate of caso 3milky-white color. Visually the beginning of solution turbidity in aqueous-alkaline bubbler 3 determine the actual value of the initial temperature T0accidentally (utrs) of the sample when it is re-heated. Temperature logger 13 in automatic mode gives the graphs of dependences of temperature change of the sample at the outlet of the reactor T°C from time t blowdown coal air per minute, with 2-fold heating the reactor to a temperature not exceeding the initial temperature of accidentally coal (utrs), where curve 1 corresponds to the first cycle of heating and curve 2 - re-cycle heating conducted after cooling the reactor to room temperature, T1the point of intersection of curves 1 and 2, the angle α is their difference, δt is the temperature change in the first and second cycle of heating samples of coal. The value of T0=70°C at the point of divergence of the curves 1 and 2 for non-oxidized coals (figure 4) and T0=90°at the point of divergence of the curves 1 and 2 for oxidized coals indicates decrease the initial temperature of accidentally coal that occurred when re-heating of the sample.
Angle of divergence of the curves of drying and re-heating (figure 5) determine the velocity V of the exothermic reaction. The resulting difference of divergence of the curves separately for the non-oxidized (figure 4) and oxidized (figure 5) borehole compare with the results of simultaneous differential thermal (DTA), thermogravimetric (TG) and mass spectrometric (CCO2analysis of control duplicate samples on the instrument STA S.
For research were used reference samples oxidized and not oxidized coal grade B shahtoplastov lignite deposits of the Khabarovsk Krai, prone to spontaneous combustion. Samples were selected point or furrow method depending on the capacity and structure of the coal seam. To prevent coal from further oxidation during transportation to the place of laboratory tests, Rostov-on-don), lumpy material samples were gerotziafas and were placed in plastic bags with a special marking.
Preparation of samples for laboratory tests were fragmentation and dispersion of powdered coal fractions: a 3.0-0.5 mm, 0.5 to 0.16 mm and less than 16 mm, the Processed sample was distributed according to the standard plastic bottles 250-500 ml, in which they were stored until further testing. From coal fractions of 3.0-0.5 mm were cut-briquettes for the evaluation of microcracks and the degree of oxidation of the coal petrographic method according to GOST 8930-94. Under the microscope, when the increase is not more than 650 times were determined proportion of the total area of weathered areas of coal grains to the entire area cut-Brik is and. Counting was carried out point method (400 points), oxidation of the samples (CAp) was calculated in percentage by the formula
where is the number of points weathered squares cut-briquettes; N - number of points not weathered squares cut-briquette.
The depth of the weathering process of the studied plots was estimated by the appearance of grain disintegration rounded irregular voids and cavities leaching, and the presence in collinite wedge-shaped cracks weathering framed "dark border" oxidized coal width of 2-10 microns with lower values of vitrinite reflectance (R0). After petrographic sort of coal to non-oxidized and oxidized, material fraction 0.5-0.16 mm method Kvantovaya was divided into two parts - the main sample and the duplicate, which were placed in a desiccator with sulfuric acid and dried up natural moisture. The main microsamples were tested at pilot plant, simulating the processes of low-temperature oxidation and spontaneous combustion of coal in a laboratory environment. Duplicate samples were studied on the device STA S Jupiter, NETZSCH, Germany, 2007 by differential is but-thermal (DTA) and thermogravimetric (TG) analyses with continuous registration of release of carbon dioxide by heating the sample from ambient temperature to 500°C, to confirm the degree of oxidation. The device contains a measuring unit, power supply, thermostat, system controller TASK and the computer. Temperature range of the instrument is 25-1550°C. Sealed oven gives you the opportunity to collect without loss of indicator gases emitted from the substance when heated, and send them to the console of mass spectrometric analysis in the continuous mode of the experiment.
Each of the prepared duplicate microprobe three oxidized and three not oxidized coal weighing 30-50 mg in a special crucible was placed in a furnace device STA S and subjected to a smooth and continuous heat up to 500°C with automatic registration of the experimental curves - DTA, TG and CCO2. The results of DTA were used to study such chemical reactions as dehydration, dissociation and other physical transformations in coal under heating the samples in air. Usually this kind of chemical reactions and physical transformations are accompanied by thermal effects is exothermic in the case of heat and endothermic in the case of absorption. Many reactions, including accidentally organic matter of coal, also accompanied by changes in the weight of the substance that is fixed thermogravimetric TG curve. With mnost this method, which unlike DTA has a quantitative nature, is that the sample studied coal is heated in a furnace for continuous weighing. Obtained information about the weight loss of the original samples provide an opportunity to judge the amount of volatile components in the coal, as well as on the kinetics of the processes of decomposition, dehydration, dissociation, oxidation, and other phenomena. Thus, in many cases, the task of definition of temperature, for storing the communication stability of water molecules and hydroxyl ions.
As shown in figure 2 and 3, endothermic effects are responsible for the amount of evaporated moisture from microsamples of coal are present in the temperature range of 60-100°C and occur without allocation of CO2. With a selection of CO2corresponds to the initial temperature of accidentally coal (utrs) at T=145°C for not oxidized (figure 2) and at T=130°C for oxidized (figure 3) coals.
The maximum allocation of CO2in the temperature range 420-500°C, accompanied by an intense mass loss of the test substance TG were recorded temperature of spontaneous combustion of coal TCB, which was equal to 427,3°C for not oxidized coal (figure 2) and 465°C for oxidized coal (figure 3). Building prediction of spontaneous combustion shahtoplastov brown coals were carried out on samples of brown coal of the Khabarovsk Krai in the following way.
1. Angle RA is walking the curves of drying and re-heating (figure 4) determine the velocity V of the exothermic reaction is not oxidized coal:
2. Angle of divergence of the curves of drying and re-heating (figure 5) determine the velocity V of the exothermic reaction of oxidized coal:
3. Calculate the incubation period τnotOKspontaneous combustion is not oxidized coal by the formula
τnot OK=TCB-UTR/V=427.3°C-70°C/1.63°C/min=216,7 minutes
4. Calculate the incubation period τOKspontaneous combustion of oxidized coal by the formula
τOK=TCB-UTR/V=465°C-90°C/ 1.9°C/min=197,3 minutes
Thus obtained for each sample time values incubation period of spontaneous combustion of coals put on hypsometric plan of a mine field in areas of restraint coal seam exploration production. However, if the map plots with heterogeneous values of the incubation period of spontaneous combustion, it is concluded that the presence of focal areas of spontaneous combustion of coal and recommendations about the need for the mapping of prediction of spontaneous combustion of coal shahtoplastov.
Sources of information
1. EN 2459959 C1, E21F 5/00, publ. 27.08.2112.
2. EN 2271450 C2, E21F 5/00, publ. 10.03.2006 - prototype.
3. The method of estimating the propensity shahtoplastov of coal to spontaneous combustion. Decl. By order of the Ministry of energy of the Russian Federation from 29.04.1998 No. 151.
1. A method for predicting the propensity of coals to samov is shorney, including the measurement of the concentration of indicator gas in the test sample, wherein creating a model that mimics natural processes and hydrothermal fluidising conversion of coals in the foci of spontaneous combustion shahtoplastov to do this continuously flowing filtered water-air mixture through the crushed sample of coal, placed in a quartz reactor with a given mode of heating to a temperature not exceeding the temperature of spontaneous combustion of coal (TCB), then cooled quartz reactor to room temperature and repeat continuous flow filtration of water-air mixture and record the beginning of thermal decomposition of the sample (ito) by the reaction of the tracer gas with an aqueous-alkaline solution and on a corner the divergence of the curves corresponding to the first and re-heated on the graph according to T°C=f(t), where T C is the temperature of the sample at the outlet of the reactor, t is the time blowing coal air, determine the rate of exothermic reaction V by the formula V=δT/t, °C/min, where δT is the temperature change in the first and second cycle of heating samples of coal, then calculate the incubation period τ of spontaneous combustion of coal by the formula τ=TCB-UTR/V min, which is a prognostic factor in the propensity of coals to spontaneous combustion.
2. The method according to claim 1, characterized in that the water-Selo the aqueous solution using calcium hydroxide.
3. The method according to claim 1, characterized in that the continuous flow filtration of water-air mixture is performed by the suction pump performance 0.2-1 l/min
4. The device for implementing the method according to claim 1, characterized in that it comprises a quartz reactor in the form of long tubes to accommodate samples of coal, automatic suction pump with rotameter, water-alkaline bubbler made of transparent glass, removable heater covering the quartz reactor at its input connected to the block temperature control, while a quartz reactor with inlet and outlet fittings, which are fitted with air filters made of glass wool, the ends of the quartz reactor equipped with sealed plugs through the two holes in the tube, located at the exit of the quartz reactor, skipped electrodes, the outputs of which are connected the temperature logger, quartz reactor through an outlet fitting connected with an aqueous-alkaline bubbler flexible hose on the end of which a spray of air, immersed in an aqueous-alkaline solution, and an aqueous-alkaline bubbler through the nozzle is connected by a flexible hose with a rotameter aspirator.
5. The device according to claim 4, characterized in that the volume of the quartz reactor is 150 cm3.
6. The device according to claim 4, characterized in that the flowmeter aspirate is and has a capacity of 0.2-1 l/min
7. The device according to claim 4, characterized in that the volume of the bubbler is 0.5 liters
8. The device according to claim 4, characterized in that the air filters are made of glass wool.
9. The device according to claim 4, characterized in that the electrodes thermocouples made of chromel-alumel.
10. The device according to claim 4, characterized in that as the aqueous alkaline solution in Barbulators used calcium hydroxide CA(Oh)2.
SUBSTANCE: fuel or air stream is passed at a constant rate through a water separator consisting of multiple cells arranged in series one after the other, formed by a coagulator and a separating grid, and water obtained from separation on a porous partition wall is removed into a settling tank. Pressure in front and behind the partition wall is constantly or periodically measured; information on the pressure measurements is transmitted to an analytical recording unit; hydraulic resistance of the porous partition wall is calculated based on the pressure difference; the obtained data are then used to determine the amount of water retained by the porous polyvinyl formal of the coagulator; based on the obtained calibration data on change in hydraulic resistance of the porous partition wall depending on water content in the coagulator and in the fuel stream, and based on said data, the amount of water contained in the fuel is determined. An apparatus for realising the method is also described.
EFFECT: high accuracy and reliability, easy determination.
8 cl, 2 dwg
SUBSTANCE: amount of resins before and after washing with n-heptane (washed resins) is determined according to GOST 1567, and presence of a detergent additive in the motor petrol is determined from the difference in the amount of resins before and after washing with n-heptane. There are no detergent additives in the motor petrol if there is no difference between the amount of resins before and after washing with n-heptane. Conversely, if a detergent additive was added to the petrol, there is a considerable difference in the amount of resins before and after washing with n-heptane.
EFFECT: high reliability of determination.
SUBSTANCE: invention relates to methods of inspecting explosive substances and forensic identification preparations. The method of labelling an explosive substance involves adding a labelling composition to the explosive substance, said composition containing identifiers, the number of which is equal to the number of properties to the labelled. The identifiers used are a mixture of polyorganosiloxanes with different molecular chain lengths, wherein each property matches an identifier in form of a polyorganosiloxane with a corresponding molecular chain length and corresponding "exit time" (retention) on a chromatogram. Thus a "chemical barcode" is formed in the explosive substance, which is read from the chromatrogram based on the principle of the presence or absence of a component at a certain time of its "exit" (retention). The method is suitable for labelling mixed and separate explosive substances, as well as components thereof, for example inorganic oxidants, particularly ammonia nitrate.
EFFECT: method provides high reliability of identifying an explosive substance with a simple process of determining its code.
SUBSTANCE: method involves determining resins washed with n-heptane in gasoline before and after adding the analysed additive according to GOST 1567, wherein the gasoline used contains washed resins in amount of at least 5 mg per 100 ml gasoline (e.g. secondary gasoline - catalytic and thermal cracking, viscosity breaking, coking, polymerisation etc, usually with high content of olefin hydrocarbons). The analysed additive is added in amount of 0.03-0.1 wt %. Presence of detergent properties in the analysed additive is determined from the difference in the amount of washed resins in the gasoline before and after adding the analysed additive.
EFFECT: high reliability of determination.
SUBSTANCE: method involves measuring the reaction force of gasification products when burning a sample of solid fuel, armoured on the side surface, wherein the reaction force and time for complete combustion of the sample of solid fuel placed in a constant volume explosion apparatus are measured, at pressure in the range of (0.5-1.5)MPa, generated by an inert gas, e.g. nitrogen or argon, wherein the volume of the explosion apparatus and the mass of the sample are in a given ratio, and the value of the unit pulse of is determined using a calculation formula.
EFFECT: enabling determination of a unit pulse using small fuel samples in laboratory conditions without using large stand equipment and explosion-proof boxes.
SUBSTANCE: method, which is meant for establishing safe application and combat applicability of artillery munitions, involves sample collection by applying filter paper to liquid droplets on the surface of ballistit powder, followed by dissolving the collected sample in acetone or water heated to 80°C, with addition of 10% potassium hydroxide solution after dissolving in acetone or copper hydroxide after dissolving in water and with evaluation of the result from the colour of the solutions in red-violet colour in the first case or light-blue colour in the second case.
EFFECT: rapid confirmation of detection.
FIELD: oil and gas industry.
SUBSTANCE: in process of method realisation on the basis of quality parameters of field coal determined at the stage of exploration and process testing, the lower calorific value of this field coals is determined for any condition of fuel according to the specified formula, a curve of coal lower calorific value dependence on moisture and ash content is built, and efficient determination of coal lower calorific value is carried out by readings of operating moisture and ash content with the help of the curve.
EFFECT: simplification and increase of determination efficiency.
3 tbl, 1 dwg
SUBSTANCE: content of monomethyl aniline in motor gasoline is determined using an indicator test agent from colour transition thereof after coming into contact with a sample of the analysed gasoline. The indicator used is 4-methoxybenzenediazonium tetrafluoroborate which is deposited on a solid support. The indicator test agent used is either reagent test paper, the solid-phase support-base used being rapid test paper, wherein content of monomethyl aniline is determined from change in colour of the paper from white to pink, light-red, red or maroon, or an indicator tube, the solid-phase filler-base used being silicon dioxide, and content of monomethyl aniline is determined from the length of the dark-red coloured area of the tube.
EFFECT: high reliability and accuracy and simple analysis.
2 cl, 5 ex, 1 tbl, 3 dwg
SUBSTANCE: invention relates to a method of producing a fraction of polymethyl-substituted C18-C36 alkanes of formula: , where n=4-10 by reacting molten atactic polypropylene with atmospheric oxygen at 150-250°C for 1-6 hours with air flow rate of 0.6-1.9 l/min∙kg using secondary low-molecular oxidation products as raw material. The method is characterised by that first, low-molecular products are fractionated collection of the basic fraction at 200-310°C followed by catalytic hydrofining from impurities of alkenes in gas phase or oxidation of alkenes at 100°C with aqueous solution of KMnO4 with weight ratio of the fraction to KMnO4 of 2.5-3.0:1.0, followed by freezing the organic layer at minus 20°C and separating the crystalline water-containing precipitate. The invention also relates to use of said fraction as a chemical marker for hydrocarbon fuels.
EFFECT: disclosed marker has a low cost and high concealment.
2 cl, 5 ex, 1 tbl, 4 dwg
FIELD: weapons and ammunition.
SUBSTANCE: invention relates to application of a compound for detection of availability of a vegetated explosive substance on the surface of combustible cartridge cases, combustible cylinders, from which missiles are made for tank guns. To confirm availability of the defect of combustible cartridge cases and combustible cylinders it is proposed to analyse observed crystals for determination of their qualitative composition.
EFFECT: method improvement.
FIELD: fire prevention facilities.
SUBSTANCE: invention relates to the field of providing fire safety and explosion safety, and in particular to methods of preventing ignition, explosion and detonation of hydrogen-air mixtures. The method of preventing detonation and destruction of stationary detonation wave lies in adding of inhibitor - propane or mixture of propane-butane into a hydrogen-air mixture. The components are mixed, the mixture is exposed to ensure complete mixing of its composing components, and the mixture is fed into the reactor evacuated to a pressure of 100 Pa, and a section of initiation evacuated to a pressure from 80 to 90 kPa. The section of initiation is filled with stoichiometric oxygen-hydrogen explosive mixture until achievement of the total pressure in the reactor and the section of initiation of 100 kPa. The detonation is initiated in the explosive mixture and it is recorded in the test inflammable mixture. The ratio of components in the test mixtures, in vol.%: hydrogen is 25.0-55.0, propane is not less than 2.5, air is up to 100 or hydrogen is 20.0-57.0, propane-butane is at least 2.5, air is up to 100. The mixing time of gaseous components of the test mixtures is not less than 15 hours.
EFFECT: ability of use of cheaper and more affordable inhibitor that has less chemical aggressiveness to the materials.
4 dwg, 1 tbl
SUBSTANCE: dust-removing composition for treating dusty surfaces contains a polyelectrolyte and water, and is characterised by that it contains aqueous solutions of an alkali metal polyacrylate and a copolymer of acrylamide with acrylic acid derivatives, wherein copolymers of acrylamide with dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate or dimethylaminopropyl acrylamide are used, the alkali metal polyacrylate solution has concentration of 0.1-1.0 wt %, the solution of the copolymer of acrylamide with acrylic acid derivatives has concentration of 0.05-0.5 wt %.
EFFECT: good erosion resistance of the treated surface.
SUBSTANCE: method of mine insulation involves preliminary determination of rock deformation depth around the mine to be insulated. Further, a system of blast holes not deeper than rock deformation zone is created in insulation area before bridge erection. Blast holes are positioned in fan pattern, with at least three rings formed across the mine to be insulated. Work agent is loaded to blast holes till intake is exhausted. Then, airtight bridges are installed in blast hole intervals between outermost rings, and gas medium is pumped to space between bridges to maintain gas pressure in space between bridges not lower than pressure in the insulated mine during the whole mine insulation period.
EFFECT: enhanced reliability of mine insulation by sealing surrounding rock fractures regardless of fracture position and formation time.
3 cl, 1 ex, 4 dwg
SUBSTANCE: method includes supply of inert gas in mined space in liquid condition. At the same time the inert gas is supplied in a tightly closed reservoir with a broken shell. The reservoir shell is damaged at the specified temperature and is controlled by variation of dimensions and mechanical strength of the shell. Tightly sealed reservoirs are fed to the mined space along wells drilled from the surface or from mines, or are placed in the mined space at the bottomhole side, if lava is moving.
EFFECT: improved efficiency of fire fighting in mines, safety of mining works.
SUBSTANCE: method consists in collection of data related to depth of mining operations h, length of working face LE of the value of excavated stope ℓ with falling angle α and its capacity m, rate of working face advance ν, weighted average coefficient of coal strength f, stresses in an untouched massif σ0 and on the face line σз, primary ξpr and secondary ξ0 steps of roof collapse, strength limit of rocks for simple compression σ com, rheological parameter α, reduced time t, coefficient of concentration of stresses K and distance from the face to maximum pressure Xav. Specified data is substituted into a mathematical formula, if any of the specified data is produced by calculations. Using the value of outburst hazard value, working face outburst hazard is decided.
EFFECT: higher efficiency of prediction due to selection of technical parameters that most accurately characterise conditions for uncoupling of a spontaneous outburst of coal and gas.
3 cl, 1 dwg
SUBSTANCE: method consists in detection of mining operations performance depth from surface, section of a mine by coal, pressure of gas in an untouched bed massif, coefficient of weighted average coal strength in a bed, coal adhesion, stress in a coal massif along a face line and area of coal massif unloading in front of the face. The specified data is substituted into a mathematical formula, with the help of which prediction of outburst hazard of a development drift R is made. If R>0, the bed is related to outburst hazardous, and if R<0 - to safe regarding coal and gas outbursts.
EFFECT: possibility to apply the method both when tunnelling and at the design stage due to use of technical characteristics of mines carried out under similar conditions or being at the stage of design solutions.
SUBSTANCE: method includes drilling of wells between earth surface and roof of an underground mine, erection of an insulating barrier link by supply of a hardening material into an underground mine whenever an emergency occurs related to self-ignition of coal. The section of the underground mine in the place of erection of the isolating barrier link is worked with increased height, which is gradually increased from borders of this section to its middle. The well is drilled between earth surface and a point with maximum height of the underground mine, and supply of the hardening material into a mine is carried out to complete filling of the section with increased height with hardening material. On the borders of the section with increased height of the mine prior to start of hardening material supply into an underground mine, barriers are installed, width of which is accepted as equal to or less than the width of the mine in the place of barriers installation, and the height of the barriers is determined using a special expression.
EFFECT: increased reliability of isolation of an emergency section in case of underground fires and reduced material and labour inputs.
SUBSTANCE: set of inventions relates to safe deep mining of solid hydrocarbons. Proposed method proceeds from continuous ground monitoring of geodynamic state of massif and seismic activity of bed roof and bed working on surface area covering bed headway in real time by passive prospecting seismology methods. Obtained results are automatically processed to isolate zones with abnormally-high seismic energy emission, define their area and depth coordinates so that map of anomalies of seismic emission. Maximum magnitudes of seismic emission are used to define coordinates of slope ratio of coal bed fracturing well. Development of main cracks is forecast from the well by the method of double refraction of transverse waves from surface excitation source. After fissuring, direction of main crack development in face bulk is controlled. Area is drilled from surface in directions of main crack development to pump methane out from the wells. With seismic emission decreasing, possibility to extract coal is forecast.
EFFECT: higher safety and intensity of coal extraction.
3 cl, 3 dwg
SUBSTANCE: method to prevent explosion of a gaseous mixture includes removal of combustible gas from a monitored room through ventilation. At the same time it is additionally burnt by periodical ignition, with one or several electrical dischargers, controlled with a timer. Dischargers are installed in the monitored room around potential areas of combustible gas leakages at the minimum distance sufficient for its ignition. The ignition period is defined with the minimum time for creation of an explosive gaseous mixture around the discharger and is set with the timer's programme.
EFFECT: higher efficiency of preventing explosion of a gaseous mixture.
SUBSTANCE: method includes well drilling between surface and roof of underground mine working, delivery of hardening material to the mine working in case of emergency situation related to coal fire breeding. Section of underground mine working is driven in the place of isolating barrier wall erection; height of mine working is increased towards the middle of the section. Well is drilled between ground surface and point of maximum height of underground mine working. Hardening material is delivered to the mine working till mine working section driven with various height is completely filled. Maximum height of mine working in the middle of this section is determined by expression hmax≥hb+tgφ·b/2h where hmax is maximum height of underground mine working on the section of isolation barrier wall erection, m; hb is height of underground mine working outside the section within which isolation barrier wall is erected, m; φ is angle of hardening material spreading, degrees; b is width of underground mine in the rough, m.
EFFECT: improving reliability of emergency section isolation during underground fire.
FIELD: mining industry; methods and devices for localization of explosion of methane-and-air mixture and coal duct.
SUBSTANCE: proposed device includes bin filled with flame suppressing powder and provided with filling neck which is closed with cover and easily breakable diaphragm at its outlet. Device has pneumatic cartridge coaxially located in perforated intermediate chamber which is coaxially located in its turn in bin; it is cone-shaped or cylindrical in form. One end of intermediate chamber is rigidly secured on inner end wall bin and other end is rigidly secured at bin outlet in spryer made in form of swirler. Pneumatic cartridge has several working chambers connected with exhaust holes, actuating mechanism with spherical movable supports engageable with spring-loaded stepped piston which is located in main working chamber closing its holes; subsequent exhaust holes of working chambers are closed by spring-loaded slide valves having bypass passages of equal section which are located in working chambers dividing them; cartridge has front chamber between its housing and sliding sleeve containing gas-forming chemical agent. According to another version, device has two base modules which are connected by mirror image; each module has pneumatic cartridge and perforated intermediate chamber.
EFFECT: enhanced efficiency.
20 cl, 15 dwg