• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    1. DEVICE FOR DIFFERENTIAL THERMAL ANALYSIS OF MATERIALS, containing sample and sample vessels, heater and temperature sensors, characterized in that, in order to improve the measurement accuracy, the heater is made in the form of two radiation sources for separate heating of the sample and a standard with optical systems, and the device contains two ele. partially absorbing radiation, located between the radiation sources and vessels for the sample and the standard, two control units: one to control the heating program for the sample and the standard, the other to control the heating program for the sample in accordance with the temperature difference between the electrons that partially absorb the radiation .
    公开号:SU1111695A3
    申请号:SU782603002
    申请日:1978-04-13
    公开日:1984-08-30
    发明作者:Немет Карой；Ленарт Чаба；Надь Элемер；Барта Ласло
    申请人:Мадьяр Тудоманьош Академиа Мюсаки Фюзикаи Кутато Интезете (Инопредприятие)；
    IPC主号:
    专利说明:

    2. A device according to claim 1, characterized in that each optical system comprises an optical filter,
    3. The device according to claim 1, characterized in that the elements partially absorbing radiation are made in the form of a metal grid or a perforated metal plate.
    4. The device according to claim 1, characterized in that each element partially absorbing radiation is located near and isolated from the sample or reference vessel,
    5. The device according to claim 1, characterized in that the control units comprise a programming device, a first controller, connected by one input with a sample temperature sensor and the other with a programming device, two power sources, one of which is connected to a radiation source for heating the sample and the other with a radiation source for heating the standard, a second controller connected to the temperature sensor of the first element partially absorbing radiation, and to the temperature sensor of the second element partially absorbing radiation , the adder, the inputs of which are connected to the outputs of the first and second controllers, while the control input of the first power source is connected to the output of the adder, and the control input of the second
    1695
    The power supply is connected to the output of the first controller.
    6. A device according to claim 1, characterized in that the generator output is connected to the input of the second controller, giving a signal that compensates for the deviation of the device’s baseline, and the generator input is connected to the input of a programming device and / or signal source.
    7. The device according to claim 1, characterized in that the vessels for the sample and the reference are located in closed vacuum volumes that are separated from each other and provided with windows.
    8. Device on PP. 1 and 7, characterized in that the vessels for the sample and the reference are placed in a thermostatically adjustable metal block.
    9. The device according to claim 8, characterized in that the sample vessel is fastened on the balance beam.
    10. The device according to claim 9, characterized in that the scales for continuous measurement of mass comprise electromechanical means for compensating torque, a differential capacitor and a regulating unit located between the differential capacitor and electromechanical means.
    11. Device on PP. 7 and 10, characterized in that the windows are adapted to partially transmit the radiation.
    This invention relates to thermal analysis. Physico-chemical transformations caused by temperature changes and accompanied by mass changes can be measured by thermogravimetry (TG) or differential thermogravimetry (DTG), which determines the rate of mass change, using known devices, so-called thermo-weights. When conducting differential thermal studies, it is required that both vessels for samples, one of which is connected to the balance arm arm (when performing DTG), should be heated equally. A device for differential thermal analysis is known, comprising two crucibles for the test substance and a reference, placed inside a furnace, a thermocouple, and a recording device L11. In this device, both sample vessels are equally affected by temperature changes in the furnace. This solution has a number of drawbacks, namely, the furnace chamber has a relatively large volume, therefore its thermal inertia is also large, as a result of which the system regulation speed is limited, due to gas convection and heat radiation, ensuring the same thermal position of both vessels for the samples (especially at elevated temperatures). ) it is difficult, moreover, both sample vessels must inevitably be in the same phase environment. The closest technical solution to the present invention is a device for differential thermal analysis of materials containing sample and reference vessels, a heater in the form of a glow lamp and temperature sensors 2. When the temperature of the sample vessels deviates from the specified values, the differential change in the amount of heat obtained by both vessels for samples from an additional lamp, is carried out by rotating this lamp, mounted on the shaft at a small angle, as a result of which the amount of heat received by one vessel increases, and the other decreases. In such a device, the thermal processes that take place in the sample under study directly affect the system, by means of which the heating of the sample vessels is controlled. Therefore, rapid thermal analysis of samples of low weight using such a device is impossible. The massive sample vessels used in it have relatively high heat inertness. Another disadvantage of this device is that both the sample and the reference are placed in the same volume and therefore cannot create a different atmosphere for each of them. The aim of the invention is to improve the measurement accuracy. This goal is achieved by the fact that in a device for differential thermal analysis of materials, containing vessels for the sample and standard, a heater and temperature sensors, the heater is made in the form of two radiation sources for separate heating of the sample and the standard with optical systems. and the device contains two elements, partially absorbing radiation, located between the radiation sources and vessels for the sample and this unit, two control units: one to control the heating program for the sample and the standard, the other to control the heating program for the sample in accordance with the temperature difference between the elements, partially absorbing radiation. Each optical system contains an optical filter. Elements that partially absorb radiation are made in the form of a metal grid or a perforated metal plate. Each element, partially absorbed radiation, is located near the vessel for the sample or standard and is isolated from it. The control units contain a programming device, the first controller, one input connected to the sample temperature sensor and the other to the programming device, two power sources, one of which is connected to the radiation source t to heat the sample and the other to the radiation source to heat the reference, the second controller connected to the temperature sensor of the first element partially absorbing radiation, and to the temperature sensor of the second element partially absorbing radiation, an adder whose outputs are connected outputs of the first and second regulators, and the control of the first power supply input connected to the output of the adder, and control the second power supply input is connected to the output of the first regulator. The output of the generator is connected to the input of the second regulator, which gives a signal that compensates for the deviation of the baseline of the device, and the input of the generator is connected to the output of the programming device and / or to the signal source. The vessels for the sample and the reference are located in closed. Evacuated volumes, which are separated from each other and provided with windows. The sample and reference vessels are placed in a thermostatically adjustable metal block. The sample vessel is fixed on the scale of the balance. The scales for continuous mass measurement contain electromechanical means to compensate for torque, a differential capacitor and a regulating unit located between the differential capacitor and electromechanical means. The windows are configured to partially transmit radiation. FIG. 1 schematically shows the proposed device with a heater; FIG. 2 - vessel for the sample of the test material, incision; in fig. 3 is the same, top view, in FIG. 4 is a block diagram of a device with a vessel for a sample of a material to be tested; FIG. 5 is a block diagram of the device; in fig. 6 shows schematically a test chamber, a slit; in fig. 7 - scales and vessel for strengthening the device on the shoulder of the rocker with a sample of two separate test chambers, longitudinal section. The sample vessel 1 (Fig. 1) is made from a material of extremely low heat capacity, good thermal conductivity and low specific heat, for example, from a plate. The heating device consists of an incandescent lamp 2 and an optical system 3, which directs the rays emanating from the incandescent lamp to assembly 1 for the sample. Optical system 3 consists of one or two (respectfully elliptical) concave surface mirrors. The temperature sensor 4, which the sample vessel is equipped with, is a thin wire thermocouple that provides a small heat sink and is welded to the sample vessel from the side opposite to the sample. In order to minimize heat removal, the sample vessel 1 is attached with one or two thin wires with low thermal conductivity and high strength, which are welded to the sample vessel on the one side and to the surrounding sample vessel, for example, to the sample vessel. . The rays from the incandescent lamp 2 are directed to the sample vessel 1 in such a way that, on the one hand, they are fed to the sample vessel by a uniform beam, on the other hand they heat the wire of the temperature sensor 4 and the mountings 5 and 6 as well as the vessel 1 for the sample. In another embodiment, the sample vessel 1 is fastened with welded thermoelement wires. The course of certain processes is adversely affected by the visible radiation region. incandescent lamps 2 or part thereof. containing high energy. In order to eliminate this additional effect, an optical filter 7 can be used, which absorbs the visible radiation region or its undesirable part, placed between vessel 1 and incandescent lamp 2. Another advantage shown in FIG. 2 and 3 of the structure is the location of the temperature sensor 8 and the element 9, which partially transmits and partially absorbs the radiation between the sample vessel 1 and the incandescent lamp 2, and this element is heated due to the absorption of heat. It is preferable to use as this element a semi-transmitting beam plate with low reflectivity, or a metal perforated plate, or a grid of fine structure, and the temperature sensor 8, welded to the element 9, can be a thermoelement. The arrangement of the thermoelement is preferred so that it is heated in the same way as vessel 1, i.e. it should be placed near the vessel 1 and welded to it directly or through a connected element, preferably with a wire 10. The block diagram shown in FIG. 4 contains a current source 11 feeding the incandescent lamp 2, which is controlled by the programming device 12 through the regulator 13, to which the temperature sensor 8 of the element 9 is connected to another input, whereby the element 9 controls the intensity of the radiation coming from the incandescent lamp 2 heating the vessel 1 for the sample. In vessel 1, the temperature of the sample can be measured using a recording device 14 connected to the temperature sensor 4 of the sample vessel. The element 9 between the vessel 1 and the incandescent lamp 2 is thermally insulated from the vessel 1, as a result of which thermal processes in the material in the vessel 1 for the sample do not affect temperature control, and vice versa, the regulator does not affects the registration of thermal processes occurring in the sample, thus creating a fast control loop with good dynamic properties.
    A device whose block diagram is shown in FIG. 5. contains not less than two vessels 1 and 15 of the same design for the sample, one of which is a standard and the other material under test, the reference material being placed in vessel 15, and the material under study in vessel 1. With vessels 1 and 15 respectively, temperature sensors 4 and 16, incandescent lamps 2 and 17, optical systems 3 and 18, temperature sensors 8 and 19, and elements 9 and 20. located between the sample vessels and the incandescent lamps associated with them. With this design, it is rational to change the temperature of the reference substance according to a specific program. For this, the temperature sensor 16 attached to the vessel 15 for the reference and the programming device 12 are connected to the first controller 13, which is connected to the input of the current source 11 supplying the incandescent lamp 17, then the input of the first regulator 13 is connected via the adder 21 to the current source 22 which feeds the incandescent lamp 2, the heating vessel 1 for the sample under study. Temperature sensors 4 and 16 vessels for the sample and the reference are connected to the recording device 14, which measures the temperature difference between the vessels for the sample and the reference. In absolute symmetry, the temperature of both empty vessels for the samples should be the same, but in reality this equality is difficult to achieve.
    To reduce these thermal differences, temperature sensors 8 and 19 of elements 9 and 20 located between sample vessel 1 or sample vessel 15 and the incandescent lamps 2 or 17 connected to them are connected to two inputs of the second regulator 23, the output of which is fed to an adder 21. Due to this, the radiation incident on the sample and reference vessels is equalized, since the temperature of the elements 9 and 20 under the influence of the current supply to the incandescent lamp 17 is set at the same level, and the incandescent lamp 17 is controlled Through the regulator 23, the adder 21 and the current source 22. Since it is necessary to achieve the same temperature values of the vessels for the sample and the reference, in order to align the asymmetry that is still present, it is recommended in accordance with the invention to connect a generator 24 to the third input of the regulator 23 a signal that compensates for the deviation of the baseline of the device, and the generator 24 is connected to the programming device 12 and / or to the source 25 of the settings signals. A programming device 12 regulating the temperature of the sample vessels through a generator 24 reduces, through a generator 24, the temperature difference of the vessels for the sample and the reference with a correction signal depending on the set temperature; independent of the set temperature, the constant deviation can be compensated by using a source of 25 adjustment signals or set to the desired value.
    In the construction according to FIG. 5, more than two sample vessels may be provided. The sample vessel corresponding to vessel 15 is then used to place the reference material, and other vessels corresponding to vessel 1 for the sample are intended for samples of the material to be studied. In this case, incandescent lamps 2, elements 9, current sources 11, adders 21, second regulators 23, generators 24 or signal sources 25 in an amount corresponding to the number of additional vessels for samples, and a multichannel recording device 14 or several single-channel devices are necessary.
    In another embodiment of the device containing at least two sample vessels, the separation of the vessels for the samples and, consequently, the separation of the sealed volumes for the studied samples (Fig. 6) can be made. In order to provide the same conditions for the vessels, it is advisable to separate these
    9 .1
    The physically closed chambers 26 and 27 are formed in a block sealed by sealing gaskets 28 and 29. This block is made of a material with good thermal conductivity, and its temperature can be constantly maintained at a low temperature using water cooling. level The low temperature surrounding the sample vessels provides good heat transfer and, therefore, rapid cooling and stabilization. The chamber of each sample vessel is provided with at least one window 31 or 32, which passes the incandescent lamp radiation, a gasket 33 or 34, which can also act as an optical filter, absorbing part of the incandescent lamp radiation, as well as outlets 35 or 36 the required amount, which ensure the withdrawal of products from the executive chamber 26 and 27 and its purging with gas. In test chambers so separated, processes occurring in the same material, but in different gaseous media, can be compared.
    The device of the above construction, equipped with two devices: for the material under study and the standard, is preferably suitable for differential thermal analysis. The research speed achieved and the solutions used here allow the use of a more diverse and informative methodology than with the use of known devices.
    To measure the mass, depending on the temperature (thermogravimetry), a sample vessel is attached to the shoulder of the balance arm 37, as shown) in FIG. 7. When heated, only the sample under test is weighed, and the standard material in which weight changes can also occur, which can be used for analyzing measurements, is placed in another vessel, regardless of the sample under study. In contrast to the known devices, the heating element of the sample vessel also does not load the scales.
    The arm of the balance arm 37 is connected, for example, to an electromechanical unit that compensates and is connected through an electromechanical control device 38 to a sensor detecting 169510
    rotating scales, preferably to the differential; the capacitor 39.
    Example. In the proposed device, two vessels are used for the samples of materials under study, which are bowls of a platinum plate 0.1 mm thick, 8.5 mm in diameter, and 3. mm high, used as a temperature sensor
    0 thermoelement of chromel-alumel with a diameter of 0.05 mm, attached to the bottom side of the bowl by spot welding. Incandescent bulbs are projection lamps (8 V, 50 St), see
    5 tirovat together with an elliptical mirror; they are located under a window 31, 32 equipped with two rubber gaskets 33, 34, of an aluminum block 40 containing vessels for
    Q samples and water cooled, the window being made of quartz glass with a thickness of 2 mm or glass for light filters of the type (L 6. Glass window for light filters /; 6 filters 5 the entire visible radiation region, which at the maximum achievable temperature ensures a decrease in power approximately by 30%. Located between the sample vessel 1 and the incandescent lamp 2, element 9 is a disk made of a platinum plate with a thickness O, 1 mm, diameter 11 mm, it contains 127 holes with a diameter of 0.5 mm located above com tiugolni5 on average distance of 0.8 mm from each other. It is also the temperature sensor is a thermocouple of chromel-alumel welded to the receptacle close to the sample
    0 side of the plate. The distance between the sample vessel and element 9 is 0.8 mm.
    Platinum fasteners 5 in the form of a wire 0.5 mm thick, welded to a fork-shaped, containing 36% nickel of the balance arm of the balance or to the vessel holder for samples at a right angle, with one
    I
    the sides hold the welded sample vessel 1 and, on the other hand, with the help of two intermediate fixing wires 10 with a thickness of 0.3 mm, the perforated plate forming the element 9 is attached, and the balance arm arm is silt: and the sample vessel holder is made of steel low thermal expansion and should be protected from radiation.
    11 1
    On the other shoulder of the beam weight 37 with a length of 100 mm, an electromechanical current transducer 41 of an electrodynamic design is attached, its coil 42 through which an electric current passes moves in an air gap of 43 rma 44 constant magnet 45 and produces a counteractive moment for 10 mA leveled the permissible load of 1 g, and a permanent magnet is mounted in the cavity of the block 40.
    Medium distance from the support
    46 weight 37 is located attached to the weights sensitive plate
    47 with a size of 15x15 mm, moving between the fixed plates of the same size with the plates 48 of the differential capacitor 39 to provide observation of the position of the scales. Lead wires 49 and 50 of thermoelements forming temperature sensors 4 and 8, or lead wires 51 coils 42
    with the aid of gaskets 52 of insulating material for fastening the lever, they are applied to the pivot axis of the balance and connected in a known manner with a minimum moment to the taps. In the lid 53 containing the vessel 1 for the sample block 40 with a diameter of 200 mm, two
    512
    sealing the test chamber 26, 27 rubber gaskets 28 and 29 and a concave mirror-like domed surface 54, the latter
    formed in the material of the cover 53 and is part of the optical system 3. In the test chamber 26, 27 are two holes for purging or suction.
    With a quartz window in the proposed device, at a pressure of 1 atm, a temperature of 750 ° C is reached, the reproduction error of adjustment at the maximum cooling rate
    or heating in 1 min is less than 0, 1 ° C, and the temperature synchronization of the vessels for the samples in the unloaded or loaded with neutral material is less than + 0.15 ° C.
    Due to the dependence on the airflow temperature and thermal expansion, which becomes significant at high temperatures, scales without a sample in the temperature range of 20-750 ° C in air at a pressure of 1 atm give a correctable maximum measuring error of 0.5 mg with a reproducibility of Jr25 mg.
    The thermal time constant during the spontaneous cooling was 8 s.
    i
    S s
    srig.Z
    /four
    Srig.
    FIG. 6

    "
    iZl

    "M
    权利要求:
    Claims (11)
    [1]
    1. DEVICE FOR DIFFERENTIAL-THERMAL ANALYSIS OF MATERIALS, containing vessels for the sample and standard, a heater and temperature sensors, characterized in that, in order to increase the accuracy of measurements, the heater is made in the form of two radiation sources for separate heating of the sample and standard with optical systems, and the device contains two elements, partially absorbing radiation, located between the radiation sources and vessels for the sample and standard, two control units: one for controlling the heating program nitrogen and reference, the other - to control the sample heating program in accordance with the temperature difference between elements partially absorbing radiation.
    SU <„> 1111695
    Fig!
    111
    [2]
    2. The device according to π. 1, characterized in that each optical system contains an optical filter,
    [3]
    3. The device according to p. 1, characterized in that the elements partially absorbing radiation are made in the form of a metal mesh or perforated metal plate.
    [4]
    4. The device according to claim 1, characterized in that each element, partially absorbing radiation, is located near the vessel for the sample or standard and isolated from it.
    [5]
    5. The device according to claim 1, characterized in that the control units comprise a programming device, a first controller connected to a sample temperature sensor by one input, and two power sources by one input, one of which is connected to a radiation source to heat the sample, and the other with a radiation source for heating the standard, a second controller connected to the temperature sensor of the first element partially absorbing radiation, and to the temperature sensor of the second element partially absorbing radiation, the adder, the inputs of which are connected to the outputs of the first and second controllers, while the control input of the first power source is connected to the output of the adder, and the control input of the second
    695 power supply connected to the output of the first regulator.
    [6]
    6. The device according to claim 1, characterized in that the output of the generator giving a signal compensating for the deviation of the base line of the device is connected to the input of the second controller, and the input of the generator is connected to the input of the programming device and / or to the signal source.
    [7]
    7. The device according to p. 1, characterized in that the vessels for the sample and standard are located in closed evacuated volumes that are separated from each other and provided with windows.
    [8]
    8. The device according to paragraphs. 1 and 7, characterized in that the vessels for the sample and standard are placed in a thermostatically controlled metal block.
    [9]
    9. The device according to claim 8, wherein the vessel for the sample is mounted on the balance beam.
    [10]
    10. The device according to p. 9, characterized in that the balance for continuous mass measurement contains electromechanical means for compensating torque, a differential capacitor and a control unit located between the differential capacitor and electromechanical means.
    [11]
    11. The device according to paragraphs. 7 and 10, characterized in that the windows are configured to partially transmit radiation.
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    同族专利:
    公开号 | 公开日
    DD136423A5|1979-07-04|
    FR2387447A1|1978-11-10|
    PL206089A1|1978-12-18|
    CH633109A5|1982-11-15|
    GB1604481A|1981-12-09|
    PL123397B1|1982-10-30|
    DE2814951A1|1978-11-02|
    HU175262B|1980-06-28|
    GB1604482A|1981-12-09|
    US4304118A|1981-12-08|
    FR2387447B1|1982-01-15|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US3055206A|1958-08-14|1962-09-25|American Instr Co Inc|Apparatus for measuring changes in weight of samples as a function of temperature|
    US3107981A|1961-04-26|1963-10-22|Honma Minoru|Apparatus for controlled combustion|
    US3172493A|1961-07-17|1965-03-09|Oskar Glemser|Apparatus for the continuous measurement of variations in the weight of a substance|
    US3263484A|1962-04-04|1966-08-02|Perkin Elmer Corp|Differential microcalorimeter|
    GB1074366A|1965-03-10|1967-07-05|Ici Ltd|Differential scanning calorimeter|
    US3271996A|1965-11-24|1966-09-13|Paulik Ferenc|Apparatus for thermal analysis|
    US3477274A|1966-10-18|1969-11-11|Stephen A Wald|Differential thermal analysis method and means employing high frequency heating|
    DE1946423A1|1969-09-13|1971-03-25|Dr Wegner Lutz Axel|Combustion appts for radioactive biological - samples|
    NL7208956A|1972-05-15|1973-11-20|US4248083A|1979-06-29|1981-02-03|The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration|Containerless high temperature calorimeter apparatus|
    IT1177144B|1984-11-09|1987-08-26|Enrico Bovone|OPTICAL PROBE ADJUSTMENT DEVICE FOR DRYING OVENS FOR PROTECTIVE MIRROR PAINT|
    US5509733A|1993-12-21|1996-04-23|Ta Instruments, Inc.|Infrared heated differential thermal analyzer|
    FR2850460B1|2003-01-23|2005-12-30|Toulouse Inst Nat Polytech|DEVICE AND METHOD FOR THERMOGRAVIMETRY TESTING|
    US7416328B2|2004-12-28|2008-08-26|Waters Investments Limited|System and method for a thermogravimetric analyzer having improved dynamic weight baseline|
    CN102768159A|2012-07-17|2012-11-07|北京科技大学|Device and method for detecting reducibility of iron ore|
    US10823650B2|2016-11-22|2020-11-03|Ta Instruments —Waters Llc|Direct thermal injection thermal analysis|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    HU77MA2868A|HU175262B|1977-04-14|1977-04-14|Process and equipment for the thermic analysis of substances|
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