Method for selective evaluating hydratcellulose fibres as precursor with production of carbon fibres

FIELD: chemistry.

SUBSTANCE: method is described that includes heating hydratecellulose fibres, examining their thermochemical transformation into carbon fibres, and determining physical and mechanical properties, characterized in that the test HC-fibres are subjected to derivatographic analysis in comparison with a similar analysis of the HC-sample of the reference fibre, evaluating the obtained data, selecting the test HC-fibres nearest to the reference HC-fibre during pyrolysis is carried out, then the selected HC-fibre is tested for the process of the thermochemical transformation into a carbon fibre using the technology of producing a reference sample and the technology mode for producing the carbon fibre of the test fibre is corrected.

EFFECT: high efficiency of selective evaluation and process optimisation in the production of carbon fibres based on new hydrate-cellulose raw materials.

1 dwg, 1 tbl, 1 ex



Same patents:

FIELD: measurement equipment.

SUBSTANCE: invention relates to the field of investigation of materials of building structures of a building using thermal means. The method to detect parameters of a local fire includes technical visual inspection of building structures in a wood floor of a building, which were exposed to thermal gradient under conditions of the local fire; detection of a scheme of fire impact at components of the floor; determination of type and grade of building wood, indices of its moisture and density in natural condition, solidity of elements of the wooden floor, finding the normative resistance of building wood for bending and speed of its burning, differing by the fact that technical visual inspection of the building wooden floor is complemented with instrumental measurements of geometric dimensions of the burning area, a control cell of the floor in the fire site is assigned, the area of cross section of the floor cell openings is measured, the index of floor cell opening is calculated; the thickness of the charring layer is determined in the cross section of wood floor elements; the combustible material volume value is calculated, as well as mass speed of burning of building pine wood in the floor cell and coefficient of reduction of pine wood burning speed, then they detect duration of local fire and maximum temperature of local fire, which are calculated on the basis of specified ratios.

EFFECT: invention provides for valid assessment of main parameters of past fire damage, as well as reduced labour intensity and timing for technical visual inspection of thermally damaged elements of a building wooden floor.

2 cl, 4 dwg, 1 ex

FIELD: construction.

SUBSTANCE: method comprises the preliminary moistening of concrete sample and its subsequent heating, in which the thermal emission is carried out in case of discharging of 700 mm Hg and temperature of 80-300°C.

EFFECT: increase of the efficiency and acceleration of analysis.

1 dwg

FIELD: measurement equipment.

SUBSTANCE: invention proposes a small-sized instrument for quick assessment of flame-proof properties of flame-proof timber treatment, which consists of a housing made in the form of an open box-type profile, a specimen installation and positioning mechanism, a gas burner activation mechanism and a gas burner installation mechanism. An inclination angle of the specimen installation and positioning mechanism is unchanged relative to a vertical axis of the housing, and additionally, it includes a fixation device of an application point of flame to the specimen with a cut-out in the upper part of the device. All components of the instrument are installed in the cavity of the housing.

EFFECT: providing reliable test results.

4 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to a method of increasing the thermal-oxidative stability of lubricating oils, in accordance to which samples of lubricating oil are thermostatted by heating in a hermetic cup without mixing for the constant time at atmospheric pressure and fixed temperature, which at each thermostatting of the new sample is step-by-step increased in the range of temperatures, determined by the purpose of the lubricating oil, after heating sampling and testing of the thermostatted samples for resistance to oxidation are carried out. Sampled is a constant weight sample, which then is heated in the presence of air with mixing for a specified time depending on the basic base of the lubricating oil at constant temperature and constant mixing rate, the oxidised samples are photometrically scanned, the coefficient of the light flow absorption is determined, with the determination of the graphical dependence of the change of the parameter of thermo-oxidative stability evaluation on the thermostatting temperature, which is used to determine the optimal temperature of thermostatting, providing maximal resistance to oxidation, characterised by the fact that as a criterion for the evaluation of the thermo-oxidative stability of the lubricating oil taken is a resource of the thermostatted oil work capacity. In the process of testing each new thermostatted sample for resistance to oxidation the sample of the oxidised oil is sampled after equal time intervals, the coefficient of the light flow absorption is determined by photometry, graphical dependences of the light flow absorption coefficient on the oxidation time of the thermostattted oils are built at each temperature of thermostatting, and used to determine the time of reaching the light flow absorption coefficient of the selected value for each oxidised thermostatted oil at different temperatures, the graphical dependence of the time for reaching a selected value of the coefficient of absorption of the light flow of the oxidised thermostatted oils on thermostatting temperature is built with the point of the said dependence with the maximal ordinate, characterising the resource of work capacity being used to determine the temperature of thermostatting, ensuring the maximal resistance to oxidation.

EFFECT: ensuring self-descriptiveness of the increase of the thermo-oxidative stability of lubricating oils and increase of their work capacity resource.

2 cl, 1 tbl, 3 dwg

FIELD: test equipment.

SUBSTANCE: device includes gas generator and operation part with structural material sample, connected in series. Gas generator features removable mixing head. Cylindrical combustion chamber of the gas generator features ignition device and orifice plate. Operation part includes interconnected clamping flange with central hole and flange holding a sample. Central longitudinal axes of flange and sample are coincident. Internal cylindrical surface of clamping flange forms an annular slot with the sample surface, the slot joins a cavity ending with output nozzle through end outlet holes in the flange around sample.

EFFECT: possible maintenance of required pressure-heat loading modes for samples, modelling natural thermal stress state of structural materials of various aggregates operating in alternate heat modes.

1 dwg

FIELD: chemistry.

SUBSTANCE: method comprises drying a polymer solution until complete evaporation of water; heating the polymer formed after drying the polymer solution, and determining the temperature range of active decomposition of the polymer at a given heating rate, as well as the degree of decomposition of the polymer in said temperature range; drying, performing thermal analysis in the temperature range which includes the temperature range of active decomposition of the polymer, and calculating weight loss of a weighed amount of the sample of porous medium and a weighed amount of the same sample of porous medium after pumping the polymer solution; determining the weight concentration of the polymer that has penetrated the porous medium based on the obtained values.

EFFECT: high accuracy of the obtained data and rapid analysis.

6 cl, 3 dwg

FIELD: measurement equipment.

SUBSTANCE: invention refers to measurement equipment and can be used for automatic determination of metal concentration in ore. According to the method before control of grade of ore, ore passes through conveyor without metal impurities. For heating, area thermal source is used, which width does not exceed conveyor width. After time τspec when heating is finished, measured is average value of temperature based on heated surface of ore without metal T1av. Based on these measurements, formed is calibration curve. Then ore containing metal is continuously supplied to conveyor and heated. After time τspec average value of temperature Tavi is measured on each i frame. Value Tavi-T1av is determined based on calibration curve. Using value (Tavi-T1av), determined is percentage of metal in ore. Besides, a device for implementation of the above method is proposed.

EFFECT: improving reliability of determination of metal concentration in ore.

6 cl, 7 dwg, 1 tbl

FIELD: test equipment.

SUBSTANCE: test bench comprises the appliances to place the unit under test thereat, source of temperature effects with water feed and drain systems arranged under said unit and vertical screen. The latter is arranged along the edges of said source and secured at the columns and elevated above soil to vary the spacing between soil level and source lower edge. Besides it incorporates the system of protection against satellite observation of tests and unit under test. Said system comprises horizontal screen secured from above at vertical screen columns. Said vertical screen consists of metal frame and refractory metal cables spaced in parallel along the frame lengthwise axis and over width exceeding the object overall dimensions. Said cables are braided in crosswise direction at the screen centre part by nichrome bands completely covering the object outlines.

EFFECT: higher accuracy of tests, protection against observation from space.

3 dwg

FIELD: measurement equipment.

SUBSTANCE: invention relates to measurement equipment and can be used for heating and temperature measurement of specimens, which are transparent in an infrared (IR) radiation region. The invention proposes a method for determination of temperature of specimens, which are transparent in an IR region, subject to action with flows of charged particles or electromagnetic radiation, which involves heating or cooling of specimens, measurement of temperature of specimens by means of thermocouples. Specimens are placed in a closed housing made from material with high thermal conductivity and located in a vacuum chamber; air is pumped out till the pressure is 10-3-10-5 Pa; the housing is heated or cooled at the specified temperature interval. Continuous preliminary temperature measurements are performed with thermocouples located outside and inside the housing together with the test specimens till temperature stabilisation moment. Then, final temperature measurements are performed with these thermocouples at a stabilisation moment of the temperature that coincides with the temperature of the test specimen till external action with flows of charged particles or electromagnetic radiation. External action is performed; after external action is completed, a specimen temperature measurement procedure is repeated.

EFFECT: improving accuracy of determination of temperature of specimens transparent in an IR region.

1 dwg

FIELD: measurement equipment.

SUBSTANCE: group of inventions relates to measurement equipment and can be used for testing of fire-resistant efficiency of protective compounds and coatings for timber. The proposed method involves preparation of a specimen, flame action on the specimen, temperature measurement of exhaust gaseous combustion products, measurement of weight of the specimen and determination of weight loss, as per which fire-resistant efficiency is determined. Specimen weight measurement is performed continuously during flame action on the specimen and after the action is completed, and a moment exceeding the limit weight loss established by classification or moment of stabilisation of specimen weight after completion of its burning is taken as a test completion moment. This method is implemented by a device containing a chamber for arrangement of a specimen, a gas burner, an exhaust system with a thermoelectric converter, an instrument for measurement and recording of temperature of exhaust gaseous combustion products. The device is also equipped with a unit for automatic measurement and recording in time of specimen weight during fire tests, which includes a lever mechanism made so that a specimen holder can be installed and connected to a weight measurement instrument connected to the processing and recording unit.

EFFECT: obtaining more accurate data for investigation of a fire protection mechanism.

5 cl, 1 tbl, 4 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to chemical fibre technology and a method of spinning fibres from graphene ribbons. The method of spinning fibres from graphene ribbons begins with unfolding carbon nanotubes to form graphene ribbons, cleaning and drying the graphene ribbons and dissolving the graphene ribbons in a suitable solvent, preferably a superacid, to form a spinning solution. The spinning solution is used to spin such that spliced fibres are fed into a coagulation medium, also known as an anti-solvent, where spun or spliced fibres undergo coagulation. The coagulation medium flows in the same direction as the orientation of fibres formed from the graphene ribbons. The coagulated fibres, formed from the graphene ribbons, are pulled off, neutralised and washed and then wound on a spool.

EFFECT: invention enables to produce fibres from graphene ribbons.

15 cl, 7 dwg

FIELD: nanotechnology.

SUBSTANCE: group of inventions relates to the field of nanotechnologies, in particular to the technologies of production of carbon nanostructures and nanomaterials for use as substrates for applied catalysts, high-strength fillers, and relates to hollow carbon nanoparticles, carbon nanomaterial and method of its preparation. The carbon nanoparticle has an average size of not less than 5 nm, and comprises a central inner cavity and an outer closed casing enclosing the inner cavity on all sides. At that the outer casing comprises at least a pair of separate carbon layers. The carbon material comprises a mixture of hollow carbon nanoparticles comprising a central inner cavity and an outer closed casing enclosing the inner cavity on all sides. At that the outer casing comprises at least a pair of separate carbon layers, and the single-walled and double-walled carbon nanotubes. The method of producing the carbon material comprising a mixture of hollow carbon nanoparticles and single-walled and double-walled carbon nanotubes comprises catalytic decomposition of hydrocarbons at a temperature of 600-1200°C with obtaining a mixture of carbon nanoparticles, which is separated from the gaseous products and annealed at 1700-2400°C in the atmosphere of inert gas.

EFFECT: invention provides obtaining of novel carbon nanoparticles and nanomaterials having high strength at low weight, which can be used to create new composite light and high strength materials.

4 cl, 2 dwg, 3 ex

FIELD: nanotechnology.

SUBSTANCE: invention relates to a method of production of carbon nanofibres and/or carbon nanotubes. The method comprises the pyrolysis of dispersed cellulosic and/or carbohydrate substrate impregnated with a compound of the element or elements, which metal or alloy, respectively, is able to form carbides in the substantially oxygen-free atmosphere comprising a volatile silicon compound, optionally in the presence of carbon compound.

EFFECT: invention enables to obtain carbon nanotubes or nanofibres of a certain shape.

15 cl, 4 dwg

FIELD: chemistry.

SUBSTANCE: apparatus for thermal treatment of carbon-containing fibrous materials includes a carbonisation device and a graphitation device insulated from the carbonisation device, between which is integrated a device for accumulating and cooling carbonised material and/or washing and drying thereof. The graphitation device can be in the form of two identical electro-graphite furnaces which are not linked with each other and arranged in parallel one over the other. The electro-graphite furnace includes a heating element, a pipe for removing volatile products, a valve at the outlet for preventing entry of gaseous medium into the furnace, pipes for feeding an inert gas, a drive mechanism for transporting the material to be thermally treated, and a cooled metal housing with a heat insulation unit, in which there are horizontal slit-type channels for transporting material. The inlet channel is in the form of a pipe with a rectangular cross-section for removing volatile products, and between its upper and lower inner surfaces over the transported material at an inclination to said surfaces there is a graphite screen with gaps between the upper surface of the channel and the upper end of the screen, and between the lower surface of the channel and the lower end of the screen. The screen divides the heating chamber into a maximum temperature area, having a heater, and a medium temperature area.

EFFECT: high efficiency and stability of the process of thermal treatment of carbon-containing fibrous materials, high quality of the end product.

4 cl, 5 dwg

FIELD: electricity.

SUBSTANCE: nanoobjects sorting method (objects with at least one spatial dimension within the range from ~0.05 nm up to ~500 nm) wherein a) the initial mix with any primary content of electrically conductive nanoobjects and more electrically conductive nanoobjects contact any part of liquid substance surface; b) energy of the above mix of nanoobjects is transmitted so that different nanoobjects depending on degree of their conductivity are subjected to different degree of heating (per time unit), at that during any non-zero period of time upon beginning of the energy transmission T temperature is maintained in any part of the above contact substance surface at the level sufficient for compliance with at least one of the following conditions: (1) temperature T differential module for any part of the above surface of the contact substance and temperature of its active evaporation (Te) is less than ΔTn (i.e. |Te-T|<ΔTn), (2) temperature T differential module for any part of the above surface of the contact substance and temperature of the active chemical reaction threshold with the above substance (Tcs) is less than ΔTn (i.e. |Tcs-T|<ΔTn), (3) temperature T differential module for any part of the above surface of the contact substance and temperature of the active chemical reaction threshold with nanoobjects (Tcn) is less than ΔTn (i.e. |Tcn-T|<ΔTn)), and moreover it is provided that nanoobjects heated up to different temperature (Tn) are subjected to different degree of fixation with the contact surface (up to failure to fix), c) non-fixed and weakly fixed nanoobjects are separated from the surface and d) at least one spatially separated object is received out of pluralities of nanoobjects, which contains nanoobjects with the average conductivity differing from the average conductivity of nanoobjects in the initial mix.

EFFECT: improving the efficiency of sorting.

7 cl, 1 dwg, 12 ex

FIELD: chemistry.

SUBSTANCE: invention relates to chemical technology, in particular to processes of carbonisation of fibrous viscose materials, and can be used in production of graphitised fibrous materials, used as filling agents of composite materials; electrodes; flexible electric heaters; filters of aggressive media; in products for sport and medical purposes, etc. The material is preliminarily subjected to relaxation processing. The obtained material, which contains a pyrolysis catalyst, is continuously transported through zones of carbonisation heating. Carbonisation is carried out to 320-360°C in not less than three zones of heating, heat- and gas-isolated one from another by transporting material with inclination from bottom to top, with increase of heating temperature from 160-200°C in the first zone by 40-60°C in each next zone of heating, in comparison with the previous one. Volatile products are simultaneously removed from the said zones into the evacuation zone, heat- and gas-isolated from the external environment and located above the heating zones and connected with them via a perforated wall. Temperature in the evacuation zone of volatile substances is set by 5-15°C higher than temperatures of the respective heating zones, temperature of the output branch piece being 5-15°C above the maximum temperature of carbonisation.

EFFECT: invention ensures increase of the process efficiency and improvement of quality of the obtained carbon fibrous materials.

2 dwg, 1 tbl, 5 ex

FIELD: chemistry.

SUBSTANCE: method involves treating viscose fibre material with pyrolysis catalysts, heating to carbonisation temperature and subsequent graphitation to temperature of 3000°C in an inert medium. Carbonisation is preceded by preparation of precursor by preliminary washing of the starting material with water and/or 5-10% sodium hyposulphite solution with heating and drying, and/or ionising irradiation with a beam of fast electrons during transportation through the irradiation chamber of an electron accelerator, and/or warm-wet synthesis of a complex catalyst on the surface of viscose fibres and in the pore system thereof in boiling 10-20% aqueous ammonium chloride solution and with addition of diammonium phosphate in ratio of 0.5-4.0, followed by steaming in hot steam and final ventilated drying with constant transportation, which enables to deposit the catalyst in form of an amorphous film.

EFFECT: high stability of the process of carbonising viscose fibre material and improved physical and mechanical properties of the obtained carbon material.

6 cl, 7 dwg, 1 tbl, 12 ex

FIELD: chemistry.

SUBSTANCE: invention relates to modification of the surface of inorganic fibre by forming a highly developed surface of inorganic fibre used as filler by forming carbon nanostructures on the surface of the fibres and can be used in producing high-strength and wear-resistant fibre composite materials. The method of modifying the surface of inorganic fibre involves the following steps: (a) soaking inorganic fibre with a solution of an α2 sinter fraction in organic solvents; (b) drying the soaked fibre; (c) heat treatment of the soaked inorganic fibre at 300-600°C; (d) depositing a transition metal salt onto the surface of the fibre heat treated according to step (c); (e) reducing the transition metal salt to obtain transition metal nanoparticles; (f) depositing carbon onto the transition metal nanoparticles to obtain carbon nanostructures on the surface of the fibre. The composite material contains modified fibre made using the method given above and a matrix of polymer or carbon.

EFFECT: high strength of the composite material in the cross direction relative the reinforcement plane by preventing surface deterioration when modifying with carbon nanostructures.

9 cl, 3 ex, 1 tbl, 5 dwg

FIELD: process engineering.

SUBSTANCE: proposed method comprises processing initial cellulose fibrous material by liquid-phase composition containing silanol groups with molecular weight varying from 900 to 2400 and viscosity varying from 520 to 1700 cPs, and 2-7%-water solution of fire retardant. Processed material is dried to 105-125°C for 60-120 min. Then, carbonisation is performed in air at 140-170°C for 25-40 min. Carbonisation is terminated at 700°C to proceed with high-temperature processing at, at least, 2200°C.

EFFECT: high physical properties and yield.

4 cl, 6 ex

FIELD: chemistry.

SUBSTANCE: invention relates to heterogeneous catalysis and can be used to recycle hydrocarbons and halogen-substituted hydrocarbons when producing composite materials, catalysts, sorbents and filters. Catalytic pyrolysis of hydrocarbons is carried out at 500-700°C on a catalyst obtained by dispersing articles of solid nickel and alloys thereof with other metals, e.g., iron, chromium, as a result of reaction with 1,2-dichloroethane vapour. The catalyst contains dispersed active nickel particles attached to carbon nanofibres with diameter 0.1-0.4 mcm. The starting material used is bromine- or chlorine-containing hydrocarbons, alkanes, olefins, alkynes or aromatic hydrocarbons, e.g., ethane, propane, acetylene, benzene. Output of carbon nanofibres is equal to or more than 600 g per 1 g metal.

EFFECT: high efficiency of the method.

5 cl, 2 dwg, 9 ex

FIELD: production of charcoal-fibrous adsorbents.

SUBSTANCE: the invention is dealt with the field of production of charcoal-fibrous adsorbents, in particular, with devices of charcoal-fibrous materials activation. The installation contains a vertical furnace for activation of a carbon fabric and a conjugated with it steam generator, which are connected to the power source and a control unit. And at the furnace output there is a reception device. At that the furnace contains a through heated muffle, through which the treated charcoal-fibrous fabric is continuously passing. At that the muffle is located inside the detachable heat-insulating furnace body, on the inner side of which there are heating elements. Besides at the furnace outlet there is a movable container with water, in which the lower end of the through muffle is dipped. The invention offers an installation for production of activated charcoal-fibrous material, which ensures a continuous process of treatment of the charcoal-fibrous material with an overheated steam and formation of the activated fabric with high mechanical properties and a cellular structure, simple in assembly and reliable in operation.

EFFECT: the invention ensures production of the activated fabric with high mechanical properties and a cellular structure, simple in assembly and reliable in operation.

8 cl, 4 dwg