JP4598977B2 - Burning rate measuring device, limit combustion-supporting gas concentration measuring method, and method for handling powdery or granular substances - Google Patents

Description

【００３２】
【発明の効果】
本発明の燃焼速度測定装置によれば、密閉恒温槽内で任意の温度、任意の圧力、任意の支燃性ガス濃度で燃焼速度試験を行うため、実際に試料が取り扱われる雰囲気下と同様の条件で試料の危険性を評価することができるという効果がある。
【００３３】
また、支燃性ガスの濃度を任意に設定できるため、様々な支燃性ガス濃度条件下で試験を行うことにより、試料が燃焼しない、または燃焼が継続しない限界支燃性ガス濃度を見出すことができるという効果がある。
【００３４】
さらに、上記限界支燃性ガス濃度にもとづいて、試料を取り扱う設備中の支燃性ガス濃度を限界支燃性ガス濃度以下にすることによって、試料を安全に取り扱うことができるという効果がある。
【図面の簡単な説明】
【図１】本発明における燃焼速度測定装置を示す構成図である。
【図２】本発明における燃焼速度測定装置の着火手段を示す拡大平面図である。
【図３】試料成型方法を示す分解説明図である。
【図４】試料成型器を示す断面図である。
【図５】成型試料を示す斜視図である。
【符号の説明】
１…燃焼速度測定装置、２…恒温槽、３…ガス供給手段、４…試料、５…着火手段、６…断熱材、７…電熱線、８…駆動装置、９…配線、１０…流量計、１１…流量計、１２…混合ガス供給管、１３…ガス排気管、１４…安全装置、１５…支燃性ガス濃度計、１６…ボックス、１７…点火スイッチ、１８…スライドトランス、１９…支燃性ガス供給管、２０…不活性ガス供給管、２１…排気量調整弁、２２…ハンドル、２３…ギア、２４…シャフト、２５…バイパス、２６…供給量調節弁[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a combustion rate measuring device, a limit combustion-supporting gas concentration measuring method, and a method for handling powdery or granular substances.
[Prior art]
[0002]
Test methods for assessing hazards when handling substances include, for example, the United Nations burning rate tests and oxidation standards specified in "Recommendations on the TRANSPORT OF DANGEROUS GOODS-Manual of Tests and Criteria", Second revised edition, UNITED NATIONS. For example, a chemical substance test. The burning rate test is a test to determine whether or not a sample is a flammable substance, and the oxidizable substance test is a test for determining whether or not a flammable substance is mixed depending on the nature of the sample when it is mixed with the flammable substance. It is a test for measuring whether or not there is a force that increases the burning rate or the strength of burning, and determining whether or not it falls under an oxidizing substance. These tests are similar to the EU test methods defined in the European Community (EU) Seventh Amendment Directive Guidelines.
[0003]
Usually, both the burning rate test and the oxidant test are performed in air at room temperature under atmospheric pressure.
In the burning rate test, a flame burned from a gas burner, which is the ignition source, is contacted and ignited at one end of a sample formed into a long triangular prism, and the time required for the sample to burn a length of 100 mm (burning time) is measured. If the combustion time is less than 45 seconds, it is determined that the substance is a combustible substance.
[0004]
In the oxidizing substance test, a sample molded in a cone shape with a bottom diameter of 70 mm is placed on a nichrome wire as an ignition source, and then the nichrome wire is energized to measure the burning time of the sample. The combustion time is from the start of energization until the main reaction such as generation of flame, incandescence, and increase in combustion ends. As the sample, a reference mixture in which a reference substance and a combustible substance are mixed at a predetermined mixing ratio and a sample mixture in which the sample and the combustible substance are mixed at a predetermined mixing ratio are used. The burning time is measured for both, and if the burning time of the sample mixture is less than or equal to the burning time of the reference mixture, it is determined that it corresponds to the oxidizing substance.
[0005]
The burning rate test and the oxidizing substance test described above are used in various fields, but actually, the test conditions defined in these tests (the test is performed in air at room temperature under atmospheric pressure). It may be handled under different atmospheres (temperature, pressure, inert gas concentration and supporting gas concentration, etc.), and in such a case, the above test method could not be applied. Further, there has been a need for a method for measuring the concentration of a flammable gas that can safely handle substances such as easily combustible substances and oxidizable substances, and a method for handling powdery or granular substances based on this method.
[0006]
[Problems to be solved by the invention]
An object of the present invention is to provide a combustion rate measuring device for measuring the burning rate of a sample under conditions in which the sample is actually handled, and to provide a combustion-supporting property capable of safely handling substances such as flammable substances and oxidizing substances. It is to provide a method for measuring a gas concentration and a method for handling a powdery or granular substance based on the method.
[0007]
[Means for Solving the Problems]
The combustion rate measuring device of the present invention includes a thermostatic chamber in which a sample is accommodated, a gas supply means for continuously supplying an inert gas and a combustion-supporting gas at a predetermined concentration in the thermostatic chamber, An ignition means for igniting the sample in the thermostat and a means for continuously discharging the combustion gas are provided.
[0008]
As described above, the burning rate measuring apparatus of the present invention can perform the burning rate test in an atmosphere controlled to an arbitrary temperature, pressure and gas concentration, and therefore the sample under the same conditions as the atmosphere in which the sample is actually handled. Can be assessed for risk. When the experiment is performed at a pressure higher than the atmospheric pressure, the evaluation can be performed by providing a regulating valve in each of the gas supply means and the combustion gas discharge means.
[0009]
The method for measuring the limit flammable gas concentration of the present invention is to measure the limit flammable gas concentration at which the sample does not burn or the combustion does not continue using the burning rate measuring device.
[0010]
As described above, the burning rate measuring apparatus of the present invention can arbitrarily set the concentrations of inert gas and combustion-supporting gas. Therefore, by performing tests in a plurality of combustion-supporting gas concentration atmospheres, it is possible to limit the limit combustion of the sample. This makes it possible to find the concentration of the inert gas and to determine a safe inert gas replacement amount.
[0011]
The method for handling a powdery or granular material according to the present invention is to control the concentration of a flammable gas in a facility for handling a powdery or granular material to be equal to or lower than the limit flammable gas concentration obtained by the above measurement method. is there.
[0012]
Thus, based on the measurement result of the limit flammable gas concentration of the powdery or granular material obtained by the burning rate measuring device of the present invention, the flammable gas concentration in the facility that handles the powdery or granular material is determined. By controlling and making the concentration of flammable gas always below the limit flammable gas concentration, it is possible to safely handle powdery or granular substances.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a combustion rate measuring apparatus 1 according to this embodiment. The combustion rate measuring apparatus 1 includes a thermostatic chamber 2, a gas supply means 3 for supplying an inert gas and a combustion-supporting gas at a predetermined concentration into the thermostatic chamber 2, and a sample 4 in the thermostatic chamber 2. And ignition means 5 for igniting.
[0014]
The thermostat 2 is a sealed box, and based on the detection result of the temperature sensor, the interior of the thermostat 2 can be controlled to an arbitrary temperature by an electrically operated heater and cooler. . (In the case of the thermostat 2 of the present invention, the temperature can be raised to about 250 ° C.). The thermostatic chamber 2 can also control the inside of the thermostatic chamber 2 to an arbitrary pressure by appropriately adjusting the supply amount adjusting valve 26 and the exhaust amount adjusting valve 21.
[0015]
In order to visually confirm the combustion state of the sample inside the thermostat 2, it is preferable that a transparent window is provided on the side of the thermostat 2 or a part of the ceiling. As another method for confirming the combustion state of the sample, a method of measuring the sample temperature or the temperature in the vicinity of the sample with a temperature sensor such as a thermocouple can be used.
[0016]
A heat insulating material 6 for placing the sample 4 is installed at the bottom of the thermostatic chamber 2. The heat insulating material 6 is for preventing the heat generated by the combustion of the sample 4 from being conducted to the floor of the thermostatic chamber 2, and for example, non-combustible materials such as asbestos, foam glass, foamed concrete, diatomaceous earth, and calcium silicate. Can be used. An explosion-proof port 14 is provided as a safety device in the upper part of the thermostatic chamber 2.
[0017]
The gas supply means 3 adjusts the flow rates of the combustion-supporting gas supply pipe 19 for supplying the combustion-supporting gas, the inert gas supply pipe 20 for supplying the inert gas, and the combustion-supporting gas and the inert gas. The flow meter 10 and the flow meter 11 are provided with a mixed gas supply pipe 12 for introducing a mixed gas of a combustion-supporting gas and an inert gas having a predetermined concentration into the thermostatic chamber 2. In addition, a bypass 25 for replacing the constant temperature bath with an inert gas at an early stage is provided in parallel with the flow meter 11. Further, in order to measure the concentration of the combustion-supporting gas in the thermostat 2, the thermostat 2 is provided with a combustion-supporting gas concentration meter 15.
[0018]
As the combustion-supporting gas, air or oxygen is usually used, but halogens such as chlorine and bromine, nitrogen oxides such as nitrogen monoxide, nitrogen dioxide, and dinitrogen monoxide can also be used. Examples of the inert gas include rare gases such as helium, neon, and argon, nitrogen, carbon dioxide, and the like.
[0019]
The ignition means 5 is for igniting the sample 4 and includes a heating wire 7 and a driving device 8 for driving the heating wire 7. As the heating wire 7, a wire made of a metal wire such as nichrome wire, Kanthal wire, advanced wire, etc., or a carbide such as carbon, silicon carbide, etc., having a high resistivity, a high melting point, hardly oxidized, and a low temperature coefficient. Etc. can be used.
[0020]
The drive device 8 is for remotely operating the heating wire 7 from the outside of the thermostat 2. As shown in FIG. 2 (enlarged plan view showing the ignition means 5), the rotation of the handle 22 has a plurality of gears. 23 and the shaft 24 are transmitted to the heating wire 7 so that the heating wire 7 can be moved up and down. Therefore, the heating wire 7 before energization or energized and raised to a predetermined temperature can be brought into contact with the sample 4 at an appropriate position. Moreover, the heating wire 7 is connected to the power supply by the wiring 9 (FIG. 1).
[0021]
The box 16 (FIG. 1) on which the thermostat 2 is mounted has a power supply for supplying power to the gas supply means 3 and the heating wire 7, and a control for controlling the gas supply amount, the gas exhaust amount, the temperature, and the like. The part etc. are stored. The front plate of the box 16 includes a slide transformer 18 for adjusting the amount of power supplied to the heating wire 7 and its power supply switch 17.
[0022]
The sample shape when performing the combustion test is not limited to the shape (triangular prism shape and conical shape) defined in the United Nations combustion test and oxidizing substance test, but also on the heat insulating material 6 in the thermostat 2. Any shape can be used as long as it can be installed. Further, as the sample 4, for example, a bulk material, a powdery or a granular material can be used, and if it is a paste having a viscosity capable of maintaining the shape, it is stretched on the heat insulating material 6 to form a string, Alternatively, in the case of a paste with low viscosity, the test can be performed by placing it in a box-like container.
[0023]
The burning rate measuring method using the burning rate measuring apparatus 1 of the present invention is, for example, a method based on the burning rate test or the oxidizing substance test defined in the above-mentioned “UN burning test” or “EU test method”. In addition to being usable, set the sample shape, temperature in the thermostat 2, pressure, supporting gas concentration, inert gas concentration, etc. to arbitrary conditions, and test under the same conditions as the atmosphere when actually handled. You can also. Below, an example of the burning rate measuring method based on the above-mentioned burning rate test of UN is shown.
[0024]
<Combustion rate measurement method>
1) Fill the sample filling portion 32 of the sample molding machine 31 shown in FIG.
The hardness of the filling is such that the sample molding device 31 is dropped three times from a height of 2 cm onto a hard flat surface.
2) Next, as shown in FIG. 4, the cooled flat plate-like heat insulating material 6 is placed on the sample molding machine 31 and turned upside down. Then, the sample molding machine 31 is removed and the molding sample shown in FIG. 33 is obtained. The molded sample 33 is a triangular prism having a triangular cross section and a length of 250 mm.
3) The heat insulating material 6 on which the molded sample 33 is placed is placed at the bottom of the combustion rate measuring device 1 shown in FIG. 1, and the temperature, pressure, inert gas and combustion-supporting gas concentration inside the thermostatic chamber 2 are set to predetermined conditions. Set to.
4) The heating wire 7 of the ignition means 5 is brought into contact with the ignition part 34 (FIG. 5) of the molded sample 33, and energization of the heating wire 7 is started.
5) When the molded sample 33 is ignited, time measurement is started when the molded part 33 burns up to a length of 80 mm from the igniting part 34, and a time (hereinafter referred to as a combustion time) until the further combustion of a length of 100 mm from there. Measure and obtain the burning rate (mm / s). If ignition does not occur or combustion does not propagate even after ignition, the combustion rate is set to zero.
[0025]
The critical combustion-supporting gas concentration of the present invention can be determined by the combustion rate measuring method shown above as an example. In general, if a substance lowers the concentration of a combustion-supporting gas, it does not burn below a certain level (does not ignite) or does not continue to burn (once ignited, combustion does not propagate thereafter) . The concentration of the flammable gas at this time is defined as the limit flammable gas concentration.
[0026]
Therefore, by using the combustion rate measuring apparatus 1 of the present invention, by changing a plurality of combustion-supporting gas concentrations and measuring the combustion rate in each atmosphere, the sample 4 does not burn or does not continue to burn. The concentration of flammable gas can be found. In addition, if necessary, the temperature, pressure, the type of combustion-supporting gas, the type of inert gas, etc. can be appropriately changed and measured, thereby evaluating the influence of temperature, pressure, etc. on the combustion rate. You can also.
[0027]
The powdery or granular material handling method of the present invention is based on the critical combustion-supporting gas concentration of the powdery or granular material under any atmosphere obtained by the above method. By handling the particulate matter, the concentration of the flammable gas in the handling atmosphere is always controlled to be below the limit flammable gas concentration. According to this handling method, powdery or granular substances can be handled safely.
[0028]
As the ignition means 5, in addition to the heating wire 7 shown in the above embodiment, for example, a gas burner or the like can be used.
[0029]
【Example】
EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited only to a following example.
[0030]
EXAMPLE Using a combustion rate measuring apparatus 1 as shown in FIG. 1, a plurality of supply ratios of air (using oxygen in the air as a combustion-supporting gas) and nitrogen (using as an inert gas) by a gas supply means 3 At the same time, the burning rate of potassium tert-butoxide was measured. The temperature in the thermostat 2 is controlled to 20 ° C. and the pressure to 1 atm, and the concentration of oxygen gas, which is a combustion-supporting gas, is changed in the range of 21% to 12% as shown in Table 1, The burning rate was measured. The results are shown in Table 1. From Table 1, it can be seen that if the concentration of the combustion-supporting gas (oxygen gas) is 18% or less, the combustion of potassium tert-butoxide does not continue and can be handled safely.
[0031]
[Table 1]

[0032]
【The invention's effect】
According to the burning rate measuring apparatus of the present invention, since the burning rate test is performed at an arbitrary temperature, an arbitrary pressure, and an arbitrary combustion-supporting gas concentration in a closed thermostat, it is the same as in an atmosphere in which a sample is actually handled. There is an effect that the risk of the sample can be evaluated under the conditions.
[0033]
In addition, since the concentration of the combustion-supporting gas can be set arbitrarily, the limit combustion-supporting gas concentration at which the sample does not burn or does not continue to be burned can be found by conducting tests under various combustion-supporting gas concentration conditions. There is an effect that can be.
[0034]
Furthermore, there is an effect that the sample can be handled safely by setting the concentration of the combustion-supporting gas in the facility that handles the sample to be equal to or lower than the limit combustion-supporting gas concentration based on the limit combustion-supporting gas concentration.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a combustion rate measuring apparatus according to the present invention.
FIG. 2 is an enlarged plan view showing ignition means of the combustion rate measuring device according to the present invention.
FIG. 3 is an exploded explanatory view showing a sample molding method.
FIG. 4 is a cross-sectional view showing a sample molding machine.
FIG. 5 is a perspective view showing a molded sample.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Combustion rate measuring device, 2 ... Constant temperature bath, 3 ... Gas supply means, 4 ... Sample, 5 ... Ignition means, 6 ... Heat insulating material, 7 ... Heating wire, 8 ... Drive apparatus, 9 ... Wiring, 10 ... Flow meter , 11 ... Flow meter, 12 ... Mixed gas supply pipe, 13 ... Gas exhaust pipe, 14 ... Safety device, 15 ... Combustion gas concentration meter, 16 ... Box, 17 ... Ignition switch, 18 ... Slide transformer, 19 ... Support Flammable gas supply pipe, 20 ... inert gas supply pipe, 21 ... displacement control valve, 22 ... handle, 23 ... gear, 24 ... shaft, 25 ... bypass, 26 ... supply quantity adjustment valve

Claims (4)

A thermostatic chamber in which a sample is stored;
A gas supply means for supplying an inert gas and a combustion-supporting gas at a predetermined concentration in the thermostatic chamber , comprising a supply amount adjustment valve ;
Ignition means for igniting the sample in the thermostat;
A combustion speed measuring device comprising: combustion gas exhausting means having an engine displacement control valve .   2. The burning rate measuring apparatus according to claim 1, wherein the sample is a powdery or granular substance.   A method for measuring a limit combustion-supporting gas concentration at which a sample does not burn or combustion does not continue using the burning velocity measuring apparatus according to claim 1 or 2. A method for handling powdery or granular substances, and measuring the limit flame retardant gas concentration by the method according to claim 3 using the powdery or granular substance as a sample, and the flame retardant gas concentration in the equipment was obtained . A method for handling powdery or granular substances, characterized by controlling the concentration to be below a limit combustion-supporting gas concentration.

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