Method for investigation of thermophysical properties of liquids and device for its implementation
FIELD: measurement equipment.
SUBSTANCE: method for examination of thermophysical properties of liquids is proposed. It implies that a metal probe of vibration viscosity metre equipped by a temperature sensor is placed to a metal cell with a liquid sample equipped by a temperature sensor. The probe is set to harmonic vibration mode, the cell temperature is changed by a controlled cooling-heating device. Temperature, amplitude, phase and vibration frequency of the probe are measured and density, viscosity and thermal diffusivity of the liquid is determined depending on its temperature. Measurements are made to define dependency on the temperature of the liquid's optical transmission near the probe for the moments when the probe passes its equilibrium position. Device for the method implementation comprises a cell, a controlled cooling-heating device, spherical metal probe of vibration viscosity metre placed inside the cell. The probe and the cell are equipped by temperature sensors. The cell is also equipped with a fibre-optical sensor of liquid optical transmission which is set next to the probe.
EFFECT: improved accuracy of measurement.
2 cl, 2 dwg
The invention relates to the field of study of the properties of liquids using heat tools. Can successfully be used to study dynamic processes thermally induced structural rearrangement of the multicomponent transparent liquids: diztoplive, aviation kerosene, vegetable oils, etc. of the Proposed method is the most relevant when using fluid sample a small volume.
Known dynamic way of thermophysical properties of liquids and device for its implementation [RF patent №2263305]. According to this method, in the insulated metal cuvette with a sample of the investigated liquid, equipped with a sensor of the bottom of the cuvette, place the sample investigated liquid and thermally insulated from the external environment spherical metal probe vibratissime equipped with a temperature sensor; probe vibratissime with a given driving force lead in the harmonic mode of mechanical vibrations, monotonically and continuously over time at a known law of change of the temperature of the cell by providing a thermal contact with a controlled cooling device for heating the sample at this temperature change at a rate greater than the rate setting process temperature changes of the investigated liquid, measure the temperature of the probe around the specified interval changes the fact is that the temperature of the cuvette, as well as the amplitude, phase, frequency probe and determine the density ρ, viscosity η and thermal diffusivity andWliquid depending on its temperature according to the equation of thermal conductivity of the liquid and the equation of forced oscillations of the probe vibratissime.
The known device for the study of thermophysical properties of fluids by the RF patent №2263305 includes the case in which you installed thermoelectric modules with thermo-accumulating bases item, one of the modules is connected to an adjustable source of direct current and has thermal contact with the cuvette, the second thermoelectric module is provided by means of the heat sink inside the cuvette placed measuring transducer and temperature probe vibratissime made in the form of a ball of copper or silver, measuring transducers of the probe temperature and the cell in the form of thermocouples embedded within the probe through the capillary stem and the bottom metal cuvette; probe, capillary cuvette and thermally insulated from the external environment. Vibratissime cuvette and placed in the device can move relative to each other.
Way and realizing his device have the following disadvantages:
- no possibility to determine the temperature of the cloud point and the crystallization of multicomponent fluids,
- there is no possibility of the simultaneous study of the viscosity and optical transmittance of the investigated liquid temperature, especially in the field of low temperatures, which is important when determining the temperature zones of structural adjustment multicomponent liquids.
The technical task of the present invention is to improve the completeness and accuracy assessments for heat-dependent properties of multicomponent liquids by simultaneous studies of the dependence on temperature: viscosity, density, thermal diffusivity and optical transmittance in the same local region of the sample liquids small volume at high speed and registration accuracy measurement data.
To implement the above objective, a method for thermophysical properties of liquids, in which the metal cuvette with a sample of the investigated liquid, equipped with a temperature sensor to the bottom of the cuvette, place a spherical metal probe vibratissime, equipped with a temperature sensor, probe vibratissime lead in the harmonic mode of mechanical vibrations by an external driving force, the cell result in thermal contact with a controlled cooling device for heating and monotonically and continuously over time change the temperature of the cell at a rate greater than the rate setting process temperature changes of the investigated liquid, measure the temperature probe in the whole interval and the change of the temperature of the cuvette, as well as the amplitude, phase, frequency probe and determine the density ρ, viscosity η and thermal diffusivity of the fluid, αWdepending on its temperature in a predetermined temperature range in the cooling and heating of the sample, while providing the insulation from the external environment of the cell and the probe, characterized in that it further measured the temperature dependence of optical transmittance of the liquid in the immediate vicinity of the spherical probe vibratissime in the same isothermal zone through optical fiber sensor optical transmittance of the liquid, and determining the position of the fork, the optical transmittance of the liquid and the temperature of the probe and the cell is carried out in each period of oscillation of the probe, and determining the tip position and its phase angle relative to the driving forces carried out for moments of extreme deviation of the probe from the source the equilibrium position, and the level of the optical signal to determine the moments of passage of the probe to its equilibrium position.
Also proposed a device for the study of thermophysical properties of liquids, which includes body, the cuvette is placed, ensuring thermal contact with a controlled device, cooling-heating, spherical metal probe vibratissime hosted the possibility of the installation of the displacements relative to the cuvette, when this rod probe cuvette and thermally insulated from the external environment; the inside of the probe and the inside of the bottom of the cuvette embedded temperature sensors whose output and the outputs of the position sensor probe vibratissime connected to the input of device registration and management, the output of which is connected with a controlled cooling device for heating and to the input of the Electromechanical oscillation system vibratissime. The device differs in that the cuvette equipped with a fiber-optical sensor the optical transmission fluid installed in the immediate vicinity of the probe vibratissime in the same isothermal zone.
The invention is illustrated by figure 1 and 2, showing the inventive device and the type of the cell from above.
Metal cuvette 1 with the investigated liquid in the form of sample 2 a small amount, such as 0.1÷0.2 ml, has the capability of heating-cooling by thermal contact between the bottom of the cuvette with a controlled device cooling-heating 3. The device cooling-heating can be, as in the prototype, made in the form of two thermoelectric modules based on Peltier elements with thermo-accumulating bases between them. Spherical metal probe 4 vibratissime posted with the possibility of installation of the displacements relative to the cell 1 to provide changing samples and cleaning of the cell. Inside the probe and GNC is the ri of the bottom of the cuvette embedded temperature sensors 5 and 6, respectively. The stem 7 of the probe cuvette and thermally insulated from the external environment in order to avoid the influence of uncontrolled heat flows from the external environment (see the shaded area around the cell in figure 1). The stem 7 of the probe is made in the form of a capillary tube of insulating material, through which missed the conductors of the temperature sensor 5. The sensor 5 temperature probe can be performed, for example, in the form of a thermocouple measuring junction which is placed in the probe and the reference junction is cooled housing (figure 1 shaded area) of vibratissime 8. The second sensor 6, the temperature of the cell is made in the form of either a thermistor or a thermocouple measuring junction which is placed in the bottom of the cell and the reference junction temperature-controlled.
In the immediate vicinity of miniature spherical probe 4 and at the same height with him in the same isothermal zone posted optical fiber sensor 9, which includes radiating optical fiber 10 and the receiving optical fiber 11. When this radiant fiber provided with optoisolation 12, for example, an led, and a receiving optical fiber equipped with a sensor 13, for example, a photodiode (figure 2).
As in the prototype, the cuvette is made of metal with high thermal diffusivity, such as copper. Spherical probe 4 vibratissime made of copper or silver to a diameter of boleticola millimeters, that reduces thermal inertia of the probe, and therefore the measurement error of the current temperature of the liquid. Miniature probe with amplitude less than a few microns does not cause mechanical destruction of tissue fluid and metrological characteristics of such a probe is insensitive to temperature change of the liquid under study due to the fact that the vibrational system of vibratissime outside of the cell and is at a constant temperature, and the probe is mechanically connected to the oscillating system insulating rod 7.
The outputs of the temperature sensors 5 and 6 and the position sensor 14 of the probe vibratissime connected to the input of device registration and management 15, the output of which is connected with the control input of the cooling-heating 3. Device registration and management 15 is made on the basis of the microcontroller. The necessary control commands to provide a heat mode, harmonic oscillations of the probe 4, the operation of the temperature sensors 5 and 6 of the probe and the bottom of the cuvette, radiation and reception of the optical signal, control and synchronization parameters, in particular, the sequential selection of the points of measurement are synchronized relative to the period of oscillation of the probe.
thermal time constant for a fluid is defined as τW=h2/aWwhere h is the characteristic geometrical size ol the least. When the sample volume is not more than 1 ml of the value of h is equal to several millimeters, and thermal time constant τWdoes not exceed the units or tens of seconds, allowing you to explore heat-dependent parameters of the liquid for fast processes of structureproperty liquid.
Thermal control means setting the temperature change of the bottom of a metal pan. Monotonic and continuous change cooling-heating of the cell reduces the technique of research, increases the reliability and accuracy of the analysis of liquids, for example, with large relaxation time (resin, amorphous substances with high viscosity), allows us to observe the hysteresis phenomenon of the liquid at its thermocycling.
Theoretical background of the proposed method are as follows.
In each period of oscillation of the probe measure its temperature, frequency, phase, and amplitude as extreme deviation of the probe from the equilibrium position. The measured parameters of the oscillations of the probe and its temperature allow us to determine the density ρ and viscosity η of the liquid by the equation of forced oscillations of the probe for mechanical oscillating system with one degree of freedom [Jaworski BM, Detlef A.A. physics Handbook. - M.: Nauka, 1977]:
where M is the reduced mass of oscillations is part of the system; r and mechanical impedance of the vibrating system; B - the stiffness of the vibrating system; x is the deviation of the oscillating system from the equilibrium position; F(t) is a driving force applied to the oscillating system.
Equation (1) describes quite well the behavior of vibratissime mode oscillations with small amplitude [Solov'ev A.N., Kaplun WAS vibrating method of measuring the viscosity of liquids. - Novosibirsk: Nauka, Siberian Department, 1970].
The equation of oscillations of a ball in a liquid can be reduced to the form [see Landau L.D., Lifshitz BM Hydrodynamics. - M.: Nauka, 1964]
here Fc, the force acting on the oscillating with frequency ω bulb; rCmechanical resistance of the probe; m is the added mass of the fluid; d is the diameter of the probe; η and ρ, the viscosity and density of the liquid; ∂x/∂t and the dynamics of the deviation of the probe from the equilibrium position.
Based on measurements of signals vibratissime (amplitude a, frequency ω and phase φ of forced oscillations of the probe) determine rCand m, and the dynamic viscosity η and the density ρ of the fluid is calculated by simultaneous solution of the equations (3).
The parameters rCand m - can be defined as follows
Here rinmechanical resistance of the probe with the fluctuation in the air;and
α=AR j/ARV; β=ωR j/ωRV.
where aR jAndRV, ωR j, ωRV- the amplitude and frequency of resonant oscillation of the probe in the liquid and in the air.
Measuring the parameters of the oscillations of the probe AndR j/ARVand ωR j/ωRVthe temperature of the probe in real time, find the values of rCand m. From the equation (3) determine the density ρ and viscosity η of the investigated liquids and their temperature dependence. thermal diffusivity of liquids andWis determined by solving the heat equation with the parameters measured by vibroisolation
where Tcf- the average temperature of the liquid at the time of measurement; shape factor K depends only on the geometry of a thermodynamic system and has rank m2it can be either calculated or determined experimentally p. and filling of a thermodynamic system fluid with a known dependence and W(T). More mathematical justification contained in the description to the patent of Russian Federation №2313305.
The method is as follows.
In cell 1 put the small sample size of 0.15÷0.2 ml of the investigated liquid. Then, the liquid falls probe vibratissime. Before proceeding to set the required initial temperature, for example +20°C, the investigated liquid, the probe and the cell.
The probe 4 is brought into harmonic mode of mechanical vibrations by an external driving force acting on the oscillating system 16, the cell result in thermal contact with a controlled cooling device for heating samples 3 and monotonically and continuously over time change the temperature of the cell at a rate greater than the rate setting process temperature changes of the investigated liquid. The rate of heating or cooling, set the initial and final temperature of the sample is set by the device registration and management 15, Device registration and management provides the excitation system 16 vibratissime 8 at a given frequency, sets the amplitude of the driving force also determines in each period of oscillation of the probe points of the temperature and level of the optical signal. Measuring the amplitude of oscillation of the probe vibratissime in each period of the oscillations allows you to ensure that m is ximala possible removal rate temperaturemeasuring characteristics of the sample fluid.
In the study, the temperature of the bottom of the cuvette once or cyclically cooled from the initial to the final temperature minus 40°C ÷ minus 70°C and then heated to the initial temperature continuously and monotonically.
The temperature difference between the cell and the probe can be determined from the equation of thermal conductivity of liquid thermal diffusivity. At a constant temperature cuvette temperature difference is equal to zero and thermal diffusivity of the fluid in the static mode cannot be determined. The rate of change of temperature of the cell is chosen such that the difference of the temperature probe and the cell was measured with sufficient accuracy. Continuity, monotonicity and a given rate of temperature change is provided by the device registration and management 15, and is defined functionally, mathematically.
During the study simultaneously measured signals of the temperature sensors of the probe 5 and cell 6 and the temperature dependence of optical transmittance of the liquid in the immediate vicinity of the probe vibratissime in the same isothermal zone. The use of fiber-optical sensor optical transmittance of the liquid located in the same isothermal zone probe vibratissime enables local control of the optical properties of the liquid, to assess the consistency of those who returnig changes of optical and viscous properties of the investigated liquid, to exclude the impact of changes in the liquid temperature characteristics of optisches 12 and photodetector 13, located on sluchayem and receiving optical fibers, respectively.
Also measure the oscillation amplitude of the probe, the frequency, the phase shift between the oscillations of the probe and the oscillations of the driving force and the density ρ, viscosity η, thermal diffusivity of the fluid, αWdepending on its temperature with the above dependencies (programmatically). The measurement of the temperature difference between the probe and the bottom of the cuvette allows to determine thermal diffusivity of liquids andWto explore the dependence of diffusivity on temperature. The opportunity is available due to the fact that the cooling of the cell is below that virtually eliminates convection and small (unit... tens of microns), the oscillation amplitude of the probe allows to neglect the effect of mixing fluid oscillating probe.
All measurements and calculations of the parameters bound to the parameter "current time"dimension. Measurement of the amplitude of the fork and its phase angle relative to the driving forces carried out for moments of extreme deviation of the probe from the equilibrium position, and determining the level of the optical signal passing through the sample, to produce moments of passing the probe is m its equilibrium position.
Due to the fact that the sensitive period between radiant 10 and the receiver 11 of the fibers of the fiber-optical sensor 9 is located in the immediate vicinity of the probe vibratissime, there is modulation of the optical radiation passing into the receiving optical fiber 11, the mechanical vibrations of the probe 4. To exclude the effect of this modulation on the accuracy of registration of the optical signal of the optical signal to determine the moments of passing the fork to its equilibrium position.
Measurement of the optical transmittance of the sample liquid by changing the temperature allows to investigate the temperature evolution of the structure of the liquid optical method to determine the cloud point and the crystallization of the samples, which is important for evaluation of the performance properties of motor oils, diztoplive and aviation kerosene.
Simultaneous study of the dependence of optical transmittance and viscosity of the investigated liquid temperature in a single isothermal zone allows better and more accurately describe the phenomenon of micro - and macro-structural realignment of the liquid in the process of thermostimulation [Solomin B.A. Method study of intermolecular interactions in multicomponent liquid media by the methods of nonequilibrium thermodynamics // proceedings of Samara scientific center, No. 3/2008 contents, 732-738]. Almost eskay perspective, it is important to clarify the evaluation of the operational and performance characteristics of a number of fairly transparent multicomponent liquids: petroleum, food and medical products.
The inventive method provides:
1. The possibility of simultaneous determination of the main thermo-physical (including thermo-optical properties of liquids in the process of thermostimulation using microdoses (of 0.15...0.2 ml) of the investigated liquids.
2. High speed and accuracy of registration of measurement data, which allows more detailed investigation of the dynamics of macro - and microstructural processes in the liquid when it is thermostimulation.
3. Allows you to quickly identify the critical operational parameters of liquid petroleum products.
1. The method of study of thermophysical properties of liquids, in which the metal cuvette with a sample of the investigated liquid, equipped with a temperature sensor to the bottom of the cuvette, place a spherical metal probe vibratissime, equipped with a temperature sensor, probe vibratissime lead in the harmonic mode of mechanical vibrations by an external driving force, the cell result in thermal contact with a controlled cooling device for heating the cell and monotonically and continuously over time change the temperature of the cell at a rate greater than the rate setting process temperature changes of the investigated liquid, measure the temperature of the probe throughout a given range of temperature change of the cell, and is also the amplitude, phase, the oscillation frequency of the probe and determine the density ρ, viscosity η and thermal diffusivity of the fluid, αWdepending on its temperature in a predetermined temperature range in the cooling and heating of the sample, while providing the insulation from the external environment of the cell and the probe, characterized in that it further measured the temperature dependence of optical transmittance of the liquid in the immediate vicinity of the spherical probe vibratissime in the same isothermal zone through optical fiber sensor optical transmittance of the liquid, and determining the position of the fork, the optical transmittance of the liquid and the temperature of the probe and the cell is carried out in each period of oscillation of the probe, and determining the tip position and its phase angle relative to the driving forces carried out for moments of extreme deviation of the probe from the source the equilibrium position, and the level of the optical signal to determine the moments of passage of the probe to its equilibrium position.
2. Device for the study of thermophysical properties of liquids, comprising a casing, a cuvette placed to provide a thermal contact with a controlled device, cooling-heating, spherical metal probe vibratissime posted with the possibility of installation peremeshany is relative to the cell, when this rod probe cuvette and thermally insulated from the external environment; the inside of the probe and the inside of the bottom of the cuvette embedded temperature sensors whose output and the outputs of the position sensor probe connected to the input of device registration and management, the output of which is connected with a controlled cooling device for heating and to the input of the Electromechanical oscillation system vibratissime, characterized in that the cuvette equipped with a fiber-optical sensor the optical transmission fluid installed in the immediate vicinity of the probe vibratissime in the same isothermal zone.
FIELD: measurement equipment.
SUBSTANCE: substance consists in availability of a measurement device and a thermoresistive sensor of phase condition in a device for determination of phase condition of a gas and liquid flow, and the sensor comprises a printed circuit board arranged along the axis of flow movement and rigidly fixed by one short side with a sensitive element installed on it and made in the form of a substrate, on which a film resistor of the "point" design (a thermistor) is installed. The sensitive element is installed in the reference point along the vertical axis of the pipeline cross section and is connected with the measurement device, which comprises a metering circuit and a microcontroller with program control and is designed to measure variation of thermistor resistance, connected with variation of the phase condition of the medium in horizontal layers of the gas and liquid flow, and signal processing. At the same time the sensitive element of the sensor by one short side of the substrate is fixed on the edge of the short non-fixed side of the printed circuit board. The film resistor (thermistor) placed on the substrate is displaced towards the edge of the free short side of the substrate and is arranged at the distance of not more than 0.5 mm from this edge. Contact sites designed for connection of the substrate to the printed circuit board are arranged opposite to the thermistor at the opposite short side of the substrate.
EFFECT: higher efficiency of a device to determine phase condition of a gas and liquid flow.
SUBSTANCE: method for determining temperature of full polymorphous transformation of heat-resistant two-phase titanium allows of (α+β)-martensitic class is proposed, which involves preliminary preparation of a specimen by means of multistage heat treatment of the latter, which is performed immediately in a differential thermal analysis (DTA) instrument in atmosphere of cleaned argon and its investigation using DTA method. Heating of the alloy specimen to single-phase β-area, supercooling below temperatures of active diffusional decay of β solid solution, short-term exposure and repeated heating to the single-phase area is performed. Fixation of dependence of a DTA signal on temperature and calculation of values of derivative of DTA signal on temperature is performed, and temperature of completion of full polymorphous transformation is determined as per maximum on the curve of the first derivative of DTA signal at repeated high-temperature heatinge.
EFFECT: improving determination accuracy of temperature of full polymorphous transformation in heat-resistant two-phase titanium alloys.
SUBSTANCE: oil sample is heated with one-time temperature control, the sample is continuously cooled with simultaneous measurement of shear stress. Chilling point is determined from temperature corresponding to the first abrupt increase in shear stress, and bulk freezing point is determined from temperature corresponding to the second abrupt increase in shear stress. The sample is heated to temperature of 60-80°C. Heating and temperature control of the sample is carried out while revolving the viscometer cylinder and the sample is cooled at a rate of 1-2°C per minute.
EFFECT: high information value and reliability of the analysis method.
FIELD: test engineering.
SUBSTANCE: body under study is brought into thermal contact with the reference body in the plane in which the local circular heater is located. At regular intervals of time the difference of values of the temperature between the heater and the point of plane of contact of the body under study and reference body is measured. The tests end up in excess of the specified value by the controlled dynamic parameter. The dependence of the current value of thermal activity on the temperature of the body under study is made. The structural transitions in polymeric materials are determined by the presence of peaks on dependence of the current value of the thermal activity on the temperature of the body under study.
EFFECT: improved method.
SUBSTANCE: method of determining volatility and heat of vaporisation of a mixture of liquid substances from the rate of evaporation from a flat surface involves establishing a correlation relationship between volatility values, calculated using known reference data, for individual liquid substances selected as calibration liquids, and the rate of evaporation thereof, determined based on data from thermogravimetric analysis carried out in isothermic conditions when an equilibrium state is achieved. The rate of evaporation of the analysed mixture is determined and the volatility value is found from the correlation relationship. The heat of vaporisation of the mixture of liquid substances in the analysed temperature range is determined using the relationship between the found volatility values and temperature. The value of the heat of vaporisation is determined from the value of the slope of a linear graph, the abscissa of which is the value of the inverse absolute temperature and the ordinate is the logarithm of the product of the experimentally determined volatility value and the absolute temperature value.
EFFECT: high reliability and objectivity of estimating volatility of not only individual liquids, but also mixtures thereof at different temperatures, broader functional capabilities of the method of determining volatility.
2 cl, 6 dwg
SUBSTANCE: method involves separate temperature control of cylindrical samples which make up a eutectic system, one of which has the analysed composition and the other is homogeneous, for example, consists of a pure substance. The samples are brought into contact at analysis temperature which is higher than the eutectic point, and the position of imaging point of the analysed alloy relative the solidus curve is determined from the state of the liquid layer formed between the samples.
EFFECT: invention enables more accurate plotting of a solidus curve on a phase diagram.
3 dwg, 1 tbl, 1 ex
SUBSTANCE: method of determining thermo-oxidative stability of lubricating materials involves heating the lubricating material in the presence of air and mixing. Oxidised lubricating material is then collected. Oxidation process parameters are then photometered and determined using graphical curves. Two samples of the lubricating material of constant weight are tested separately with and without a catalyst. While heating, the two samples of lubricating material of constant weight are tested successively with and without a catalyst, stirred while periodically varying testing temperature from temperature at the onset of oxidation and maximum temperature. Temperature is the lowered from maximum temperature to temperature at the onset of oxidation over a constant period of time. After each testing temperature, with and without a catalyst, the samples are weighed, the weight of the evaporated sample and evaporation number are then determined as a ratio of the weight of the evaporated sample to the weight of the remaining sample. By photometering, the light flux absorption factor with and without catalyst is determined, the thermo-oxidative stability factor is determined as a sum of light flux absorption factor and evaporation number. Further, the influence coefficient of the catalyst KVK on oxidative processes is determined using the formula KVK=KK/K, where KK and K are thermo-oxidative stability factors of samples of the lubricating material with and without catalyst, respectively. A curve of the influence coefficient of the catalyst on the oxidative processes versus the testing time is then plotted, and thermo-oxidative stability of the lubricating materials is then determined from values of the influence coefficent of the catalyst on the curve. If KVK>1, thermo-oxidative stability is falling, and if KVK<1 thermo-oxidative stability is increasing.
EFFECT: high information content of the method of determining thermo-oxidative stability of oxidation and evaporation processes during periodic variation of the testing temperature.
3 dwg, 1 tbl
SUBSTANCE: proposed method consists in measuring activity of acoustic emission signals emitted by tested specimen in heating. Polymorphic transformation temperature is defined as temperature corresponding to the moment of stepwise decrease in aforesaid activity.
EFFECT: higher accuracy and efficiency.
FIELD: instrument making.
SUBSTANCE: device for determining thermal stability of substances consists of cylindrical casing filled with warmth-keeping material, in which there coaxially placed is temperature-controlled metal cylinder with cavities made along its perimetre for arrangement of tightened reaction shells each of which is connected to pressure measurement and recording system. At that, each reaction shell is equipped with flame arrester and pneumatic drive connecting the reaction shell volume to pneumatic protector and precision temperature-compensated bipolar "pressure-voltage" converter which in its turn through multi-channel analogue-to-digital converter one of the inputs of which is connected to output of "atmospheric pressure-voltage" converter, is connected to pressure display and recording system. At that, in each pneumatic drive the provision is made for the tap which is equipped with valve connected to vacuum pump with automatic valve at the inlet, inert gas source and in-series connected pneumatic resistance and valve.
EFFECT: invention allows shortening the time and measurement period, calibration intervals, improves reliability at reducing overall dimensions and electric power consumption.
2 cl, 1 dwg
FIELD: instrument making.
SUBSTANCE: to investigate heat transfer in process of fluid metals cooling, a heat pipe is used, in which a heater of a heating zone is equipped with a controller and is arranged outside the pipe heating area. The heat pipe cooling area is made with a filling nozzle and a thermocouple arranged in it, and with cooling air. The cooling medium flow controller and the thermocouple for measurement of medium temperature are connected into the system of automatic control of the model operation. The device model is made with the scale M1=2÷5, where M1=la/lM, la - size of as-built heat pipe, lM - model size.
EFFECT: possibility to model cooling process.
FIELD: measurement equipment.
SUBSTANCE: pilot body is made in the form of a thermocouple. A device is made in the form of a vertically located fork consisting of a holder and fork legs rigidly attached to it and separated with the holder, and the pilot body.
EFFECT: alignment of points at which temperature and viscosity is measured.
4 cl, 4 dwg
FIELD: measurement equipment.
SUBSTANCE: liquid viscosity measuring device comprises a cylindrical resonant element, an excitation device, a receiving device connected through a transmission line to an amplitude detector, an analogue-to-digital converter, the input of which is connected to the output of the amplitude detector, and the output of which is connected to the first information input of the microprocessor, the first control output of microprocessor is connected to the input of analogue-to-digital converter, a microwave oscillator tuned as to frequency, connected at its input to the output of analogue-to-digital converter, and at its output through a waveguide to the excitation device. In addition, the device includes three branch pipes for inlet/outlet of investigated liquid; the first branch pipe is rigidly attached to lower end wall coaxially to vertical axis of the resonator, the second and the third branch pipes are rigidly fixed on side wall and located at the distance of 30-40 mm and 1-2 mm from the bottom of the cylindrical resonator element, a filter of parasite electromagnetic oscillations, which is made in the form of a slot on the side wall of the resonator, a device for bringing the liquid into rotation with possibility of being moved in vertical plane, and a contact device with a magnetic grab.
EFFECT: improving the accuracy of determination of kinematic fuel viscosity.
SUBSTANCE: apparatus has a crucible with the analysed sample which is coaxially suspended in the heating zone of a vacuum electric furnace on an elastic thread twisted by an electromagnetic unit, with a mirror tied to said thread. The apparatus also has a light source, a computer and a photodetector which consists of a semitransparent measuring scale and two photosensors whose output bus is connected to one of the ports of the control computer. The apparatus has at least two additional pairs of photosensors, wherein the distance between pairs of photosensors is equal and is 5-20 times greater than the centre distance of photosensors inside a pair.
EFFECT: providing accuracy, stability and continuous conduction of experiments, cutting duration of experiments, reduced loss of melt components, eliminating subjective influence on the experiment, lowering qualification requirements for the experimenter.
2 cl, 8 dwg
SUBSTANCE: device includes main wall with console, electric furnace, melting pot with molten metal and flange with screws. Two parallel flanges with coaxial holes, indication unit of electric furnace axis position and correction unit of electric furnace axis position are introduced to the device. Indication unit of electric furnace axis position is made in the form of an assembly consisting either of elastic thread suspension fixed on the level of upper point, upper end of lead and target, at that, lower end of lead freely moves above the target, or laser level and levelling target; at that, laser level is fixed on the level of upper point of elastic thread suspension. Correction unit of electric furnace axis position is made in the form of adjustable flange with several, for example, three support adjustable screws located in circumferential direction of that flange with a pitch for example of 120 degrees. One flange is fixed on the level of flange with screws, the other flange is fixed on the level of electric furnace heating zone, holes of flanges are coaxial and located at equal distance from electric furnace axis, at least 0.3 metre.
EFFECT: shortening of preparation time period for experiment, expedition and simplification of experiments, provision of uniform and predictable heating of molten metal, and comparability of experimental results.
SUBSTANCE: method is meant for contactless measurement of viscosity and electrical resistance of high-temperature molten metal. Viscosity is measured via photometric determination of parameters of torsional vibrations of a cylindrical crucible with the melt. Disclosed is a crucible device, having a crucible, a disc, a carrying cup suspended on an elastic thread in the high-temperature zone of an electric furnace, placed inside the crucible in which guide elements are introduced, fixed on the cover and inserted into corresponding holes in the disc. The guide elements are in form of tubes which link the top surface of the melt and the space over the crucible outside the crucible device and lie symmetrically about the axis of the crucible.
EFFECT: high reliability and accuracy of determining parameters of high-temperature molten metal, eg, kinematic viscosity values.
SUBSTANCE: apparatus has seven V-shaped fibre light guides (sensors) which lie in areas of possible cracking, three diode lasers, three optical radiation measuring receivers, a photoelectric signal processing unit and an information processing unit with software. The apparatus further includes seven adjustable resistors and one limiting resistor, a block of seven emitters, a block of seven receivers, a microcontroller and a transceiver. The apparatus realises the method of determining points of prefracture in structures.
EFFECT: high reliability of measuring optical signal variations in optical fibres.
4 cl, 4 dwg
SUBSTANCE: method of measuring kinematic viscosity and electrical resistance of molten metal, where the turning angle of the analysed melt sample is determined. To this end, a rotating magnetic field generated by a main magnet assembly and lying in the zone of heating the analysed sample, and a temporary additional magnetic field outside the heating zone, generated by an additional magnet assembly, are used. Trajectory parameters of the reflected light beam, corresponding to the turning angle during torsional vibrations of the crucible with the melt sample, are determined photometrically using output electrical signals of a photodetector. Electrical resistance of the melt is determined from the moment the melt is exposed to the rotating magnetic field by measuring parameters of neighbouring half-cycles of one of the initial periods of the trajectory of the reflected light bream. Further, the rotating magnetic field is switched off and the value of logarithmic decrement is determined, from which kinematic viscosity is determined. In all measurements, comparison of time values of output signals of the photodetector is used.
EFFECT: shorter time for measuring both parameters, high reliability and accuracy of measurements, broader functional capabilities, simple and cheap experiment, possibility of reducing loss of the melt and its components.
9 cl, 7 dwg
SUBSTANCE: apparatus for investigating kinematic viscosity of melts has a viscosimetric module in an evacuated or water-cooled chamber, along the axis of which a suspension system with a crucible is placed in the heating zone of an electric heater. The apparatus also has a suspension system accelerating unit, an accelerating unit switch, a mirror, a light source, a photodetector and a computer. The device also includes a visual and audio signalling unit, having at least one visual and one audio signalling device, a counter with a display. The input bus of the visual and audio signalling unit is connected to one of the computer ports. The input of the counter with a display and the computer are connected to the output bus of the visual and audio signalling unit, and the acceleration unit switch is also connected to one of the computer ports.
EFFECT: simplification and optimisation of the procedure of measuring viscosity, while cutting the measurement time and reducing wastes from melt components while maintaining reliability and accuracy of determining amplitude-time parameters of damping torsional vibrations of the crucible with the melt.
3 cl, 5 dwg
FIELD: machine building.
SUBSTANCE: vibratory flow metre (100) consists of ready-fitted flow metre (10) forming vibratory characteristic for flowing material, of sensor (50) of dimension of bubbles generating signal of bubbles measurement for flowing material and of measuring electronics (20) connected to ready-fitted flow metre (10) and to sensor (50) of bubble dimension. Measuring electronics (20) receives a vibratory characteristic and signal of bubbles measurement, determines dimension of bubbles using at least the signal of bubbles measurement, qualifies one or more characteristics of flow of current material using at least the vibratory characteristic and dimension of bubbles.
EFFECT: upgraded accuracy of measurement of flow characteristic at any level of entrained gas.
40 cl, 9 dwg
FIELD: machine building.
SUBSTANCE: procedure for determination of viscosity of magnetic fluid and magnetic colloid consists in implementation of oscillating system where magnetic fluid (MF) filling U-shaped glass tube functions as inertia-viscous element. Also, an air cavity formed inside one of bends of a tube under a piezo-electric plate functions as elastic force. The plate is attached to the end the tube. The piezo-electric plate is designed for indication of oscillations and for measurement of decay coefficient, on base of which there are obtained values of shear viscosity of analysed samples.
EFFECT: determination of viscosity of both transparent and non-transparent fluids, measurements in magnetic field important for analysis of rheological parametres of nano dispersed magnetic fluids.
2 dwg, 2 tbl
FIELD: inspection of technological fluids.
SUBSTANCE: detector has tuning fork. Axial rod of tuning fork passes through base of the tuning fork. Piezoelectric converters and counterweights are mounted at each foot of tuning fork at parting line. Tuning fork is disposed vertically and is suspended at string stretchers by axial rod. Counterweights are shifted relatively parting lines at opposite directions in such a way that at reciprocal oscillations of feet of tuning fork the periodic torque generates relatively vertical axis and sample body disposed at the end of axial rod makes torsional vibrations.
EFFECT: improved precision of measurement.