Oxygen index testing device

Abstract

The utility model relates to the field of combustion performance testing, and discloses an oxygen index testing device which comprises a base, a combustion cylinder and a sample clamp arranged in the base, one end of the combustion cylinder is embedded in the base, the sample clamp is located on the inner side of the combustion cylinder, and the other end of the combustion cylinder is embedded in the sample clamp. A lifting frame capable of clamping the combustion cylinder is arranged on one side of the base, and a driving mechanism for driving the lifting frame to be away from the base is arranged on one side of the combustion cylinder. The combustion cylinder can be clamped by the lifting frame, the lifting frame is driven by the driving mechanism to be away from the base, automatic separation between the combustion cylinder and the base is achieved, the problem that in the prior art, a sample can only be replaced by manually taking the combustion cylinder is solved, scalding accidents caused by the fact that hands make contact with the combustion cylinder are avoided, potential safety hazards can be completely eradicated, and the use safety of the device is improved.

Description

Technical Field

[0001] The utility model relates to the field of combustion performance testing, in particular to an oxygen index testing device. Background Art

[0002] The oxygen index test device is used to evaluate the combustion performance of the sample under specified test conditions, that is, to determine the minimum volume percentage concentration of oxygen that just maintains the combustion of the sample; therefore, in the oxygen and nitrogen mixed gas flow, the oxygen index test device is needed to determine the minimum oxygen concentration required to just maintain the combustion of the sample.

[0003] The oxygen index test device usually includes a combustion tube, a base, a sample clamp, a gas source and a measurement control device. The combustion tube cover is arranged on the outside of the sample clamp, and the sample to be measured is clamped on the sample clamp. The gas source, under the action of the measurement control device, introduces the test gas into the combustion tube through the diffuser ring, and then ignites the sample through the igniter, and measures the minimum oxygen concentration required to maintain its combustion.

[0004] However, in the prior art, it is often necessary to manually take the combustion tube to replace the sample, which is not only cumbersome and inefficient, but also easy to burn hands after the high-temperature combustion in the combustion tube, posing a safety hazard. Utility Model Content

[0005] The problem to be solved by the utility model is to provide an oxygen index testing device, which clamps the combustion tube by a lifting frame and uses a driving mechanism to drive the lifting frame to move, so that the combustion tube is separated from the base, thereby facilitating the replacement of the sample on the sample clamp. This process does not require manual contact with the combustion tube, and safety hazards can be eliminated.

[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0007] An oxygen index testing device comprises a base, a combustion tube and a sample clamp arranged inside the base, one end of the combustion tube is embedded in the base, and the sample clamp is located on the inner side of the combustion tube, a lifting frame capable of clamping the combustion tube is arranged on one side of the base, and a driving mechanism for driving the lifting frame away from the base is arranged on one side of the combustion tube.

[0008] In a preferred embodiment of the utility model, a placement groove for placing the combustion tube is opened on one side of the lifting frame, and a protruding support plate is provided on the side wall of the placement groove; a retaining ring is provided on the outer sleeve of the combustion tube, and the bottom surface of the retaining ring can fit with the top surface of the support plate.

[0009] In a preferred embodiment of the utility model, the driving mechanism includes a bottom plate for mounting the base, a mounting plate is fixedly mounted on the bottom plate, a support block and a linear module for driving the support block to rise and fall are arranged on one side of the mounting plate, and the support block is connected to the lifting frame by a connecting plate.

[0010] In a preferred embodiment of the utility model, the support block is located on a side of the mounting plate opposite to the lifting frame, the connecting plate is fixedly installed on the end of the support block, and one end of the connecting plate bypasses the mounting plate and is fixedly connected to the lifting frame.

[0011] In a preferred embodiment of the utility model, the linear module includes a screw rod parallel to the combustion tube, the screw rod is rotatably mounted on a side of the mounting plate close to the support block, and a nut is screwed onto the screw rod, and the nut is fixedly connected to the support block.

[0012] In a preferred embodiment of the utility model, a guide rail is fixedly installed on one side of the mounting plate close to the support block, a slider is fixedly installed on the support block, the guide rail is parallel to the screw rod, and the guide rail and the slider are slidably connected.

[0013] In a preferred embodiment of the utility model, a shell is installed on the bottom plate, and the shell cover is arranged on the outside of the linear module and the base, and the side of the shell close to the lifting frame is provided with guide grooves whose number and position correspond to the connecting plate, and the connecting plate is connected to the lifting frame through the guide groove. Beneficial Effects

[0014] (1) In the utility model, the combustion tube can be clamped by the lifting frame, and the lifting frame can be driven away from the base by the driving mechanism to realize the automatic separation between the combustion tube and the base, thereby solving the problem that the combustion tube needs to be manually taken out to replace the sample in the prior art, avoiding burn accidents caused by contact between the human hand and the combustion tube, eliminating safety hazards, and improving the safety of the use of the device.

[0015] (2) In the present invention, the combustion cylinder is located in the placement groove of the lifting frame, and the synchronous movement between the combustion cylinder and the lifting frame is achieved through the overlap between the retaining ring and the support plate. Through this structure, it is not only convenient for the lifting frame to clamp the combustion cylinder, but also convenient for the combustion cylinder and the lifting frame to be separated. The separation between the two can be completed by simply pulling the combustion cylinder out of the placement groove, which is simple, fast and highly stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the utility model;

[0017] Figure 2 It is a schematic diagram of the axonometric structure (excluding the combustion tube) of the utility model;

[0018] Figure 3 It is a schematic diagram of the internal structure of the utility model;

[0019] Figure 4 It is a schematic diagram of the position structure of the connecting plate and the guide groove of the utility model;

[0020] Figure 5 It is a schematic diagram of the position structure of the lifting frame and the mounting plate of the utility model;

[0021] Figure 6 It is a structural schematic diagram of the driving mechanism of the utility model;

[0022] Figure 7 It is a structural schematic diagram of the lifting frame of the utility model;

[0023] Figure 8 It is a structural schematic diagram of the combustion tube of the utility model;

[0024] Among them, 1. bottom plate; 11. shell; 12. guide groove; 2. base; 3. sample clamp; 4. combustion tube; 41. retaining ring; 5. lifting frame; 51. placement groove; 52. support plate; 6. mounting plate; 71. support block; 72. connecting plate; 81. driving motor; 82. screw rod; 83. nut; 84. guide rail; 85. slider. DETAILED DESCRIPTION

[0025] The present invention will now be further described in detail in conjunction with the accompanying drawings and embodiments. These drawings are simplified schematic diagrams that only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0026] like Figure 1-Figure 3 , Figure 7-Figure 8 As shown, an oxygen index testing device includes a base 2, a combustion tube 4 and a sample clamp 3 arranged inside the base 2, one end of the combustion tube 4 is embedded in the base 2, and the sample clamp 3 is located on the inner side of the combustion tube 4, a lifting frame 5 capable of clamping the combustion tube 4 is arranged on one side of the base 2, and a driving mechanism for driving the lifting frame 5 away from the base 2 is arranged on one side of the combustion tube 4.

[0027] As mentioned above, the lifting frame 5 can clamp the combustion tube 4 from the barrel part, and drive the lifting frame 5 away from the base 2 through the driving mechanism to realize the automatic separation between the combustion tube 4 and the base 2, which solves the problem of manually taking the combustion tube 4 to replace the sample in the prior art, avoids scalding accidents caused by contact between human hands and the combustion tube 4, can eliminate safety hazards, and improve the safety of using the device.

[0028] The combustion tube 4 is composed of a heat-resistant glass tube vertically fixed on the base 2 and capable of introducing oxygen-containing mixed gas. The combustion tube 4 preferably has a height of 500±50mm and an inner diameter of 75-100mm. The top of the combustion tube 4 has a flow-limiting hole, and the flow rate of the exhaust gas is at least 90mm / s; if the same result can be obtained, other sizes of the combustion tube 4 with or without a flow-limiting hole can also be used.

[0029] A limiting platform is provided at the upper inner side of the base 2 for limiting the embedding depth of the combustion tube 4, and a diffuser ring is provided at the bottom of the base 2, and the sample clamp 3 is also located on the inner side of the diffuser ring; the diffuser ring serves to evenly distribute the mixed gas entering the combustion tube 4, and preferably uses a mixing chamber containing an easily diffusible metal mesh. Other multi-purpose devices of the same type may also be used if they can achieve the same result, and a porous partition net may be installed on a horizontal plane below the sample clamp 3 to prevent falling combustion debris from clogging the gas inlet and diffusion channel.

[0030] The sample clamp 3 is located in the center of the combustion tube 4 and is used to support the sample vertically. For self-supporting materials, the clamping point is at least 15 mm away from the nearest point where the sample may burn. For films and sheets, a frame is used, and the sample is supported by two vertical frames. Marking lines are drawn at 20 mm and 100 mm from the top of the frame, and the clamp and supporting frame should be smooth to minimize interference with the rising airflow.

[0031] Furthermore, a placement groove 51 for placing the combustion tube 4 is opened on one side of the lifting frame 5, and a protruding support plate 52 is provided on the side wall of the placement groove 51; a retaining ring 41 is provided on the outside of the combustion tube 4, and the bottom surface of the retaining ring 41 can fit with the top surface of the support plate 52.

[0032] The support plate 52 also has an arc-shaped structure and protrudes from the side wall of the placement groove 51 toward the center of the placement groove 51 . The support plate 52 is located below the retaining ring 41 .

[0033] The combustion tube 4 is located in the placement groove 51 of the lifting frame 5, and the synchronous movement between the combustion tube 4 and the lifting frame 5 is achieved through the overlap between the retaining ring 41 and the support plate 52; through this structure, it is not only convenient for the lifting frame 5 to clamp the combustion tube 4, but also convenient to separate the combustion tube 4 and the lifting frame 5, which is simple, fast and highly stable.

[0034] Among them, in the horizontal cross section at the same height, the arc length of the placement groove 51 should be greater than half of the circumference of the retaining ring 41, the purpose of this is to prevent the lifting frame 5 from falling from the side opening of the placement groove 51 during a certain process. The placement groove 51 is open at both ends of the axial direction, and the combustion tube 4 can be separated from the placement groove 51 by simply pulling it out from the placement groove 51 along the axis.

[0035] like Figure 3-Figure 6As shown, the driving mechanism includes a base plate 1 for installing the base 2, a mounting plate 6 is fixedly mounted on the base plate 1, a support block 71 and a linear module for driving the support block 71 to rise and fall are arranged on one side of the mounting plate 6, and the support block 71 is connected to the lifting frame 5 by a connecting plate 72.

[0036] As mentioned above, the linear module includes a screw rod 82 parallel to the combustion tube 4 , the screw rod 82 is rotatably mounted on a side of the mounting plate 6 close to the support block 71 , and a nut 83 is screwed and sleeved on the screw rod 82 , and the nut 83 is fixedly connected to the support block 71 .

[0037] A driving motor 81 is provided at the lower end of the screw rod 82. The driving motor 81 is preferably a servo motor, which is connected to the screw rod 82 through a coupling. Driven by the servo motor, the screw rod 82 can rotate around its own axis, and the driving nut 83 can make a linear reciprocating motion along the axial direction of the screw rod 82, and then the support block 71 is driven to move up and down through the nut 83 to realize the lifting function of the lifting frame 5; wherein, the nut 83 is fixedly embedded in the center position of the support block 71.

[0038] Furthermore, the support block 71 is located on a side of the mounting plate 6 opposite to the lifting frame 5 , the connecting plate 72 is fixedly mounted on the end of the support block 71 , and one end of the connecting plate 72 bypasses the mounting plate 6 and is fixedly connected to the lifting frame 5 .

[0039] There are two connecting plates 72, which are fixedly installed at both ends of the support block 71 respectively, and the length of the support block 71 is greater than the width of the mounting plate 6 to ensure that there is no interference between the connecting plate 72 and the mounting plate 6; and the support block 71 is located on the side of the mounting plate 6 opposite to the lifting frame 5, which not only has more installation space, but also makes the overall structure more reasonable and compact.

[0040] As mentioned above, a guide rail 84 is fixedly mounted on one side of the mounting plate 6 close to the support block 71 , and a slider 85 is fixedly mounted on the support block 71 . The guide rail 84 is parallel to the screw rod 82 , and the guide rail 84 and the slider 85 are slidably connected.

[0041] There are two guide rails 84, which are symmetrically distributed on both sides of the screw rod 82, and there are also two corresponding sliders 85, which are slidably assembled with the corresponding guide rails 84; through this structure, not only can directional guidance be provided for the lifting and lowering of the support block 71, but also the rotational freedom of the support block 71 can be limited so that it can only move linearly along the axial direction of the screw rod 82.

[0042] A shell 11 is installed on the base plate 1, and the shell 11 is covered on the outside of the linear module and the base 2. A guide groove 12 corresponding in number and position to the connecting plate 72 is opened on the side of the shell 11 close to the lifting frame 5, and the connecting plate 72 is connected to the lifting frame 5 through the guide groove 12.

[0043] The shell 11 functions to package the overall mechanical structure. Being inside the shell 11 can prevent damage from external environmental factors and extend the service life. The shell 11 can also optimize the appearance design of the device to make it more beautiful. The open end of the base 2 extends to the outside of the shell 11 so that the combustion tube 4 can be inserted at any time.

[0044] In addition, in a mixed flow of oxygen and nitrogen, the steps for using the device to determine the minimum oxygen concentration required for the sample to just maintain combustion are as follows:

[0045] (1) The test device should be placed in an environment with a temperature of 23℃±2℃. If necessary, place the sample in a sealed container at 23℃±2℃ and 50%±5%, and take it out of the container when necessary;

[0046] (2) The initial oxygen concentration can be selected based on the results of similar materials. In addition, the ignition of the sample in the air can be observed. If the sample burns quickly, the initial oxygen concentration should be about 18%; if the sample burns slowly or unsteadily, the initial oxygen concentration should be about 21%; if the sample burns discontinuously in the air, the initial oxygen concentration should be at least 25%, depending on the difficulty of ignition or the length of burning time before extinguishing;

[0047] (3) Turn on the power switch, return the position of the lifting frame 5 to zero, and place the combustion tube 4. Ensure that the combustion tube 4 is in a vertical state, raise the combustion tube 4 to the top, and install the sample vertically at the center of the combustion tube 4 through the sample clamp 3, so that the top of the sample is at least 100mm lower than the top of the combustion tube 4, and the exposed part of the lowest point of the sample is 100mm higher than the top surface of the gas dispersion device (i.e., diffuser ring) of the base 2;

[0048] (4) Adjust the gas mixer and flow meter. Mix the oxygen / nitrogen gas at 23℃±2℃, and make the oxygen concentration reach the set value, and pass through the combustion tube 4 at a flow rate of 40mm / s±2mm / s. Flush the combustion tube with the mixed gas for at least 30s before igniting the sample. Ensure that the gas flow rate remains unchanged during ignition and sample combustion. Record the oxygen concentration and calculate the oxygen concentration used according to the formula, expressed as volume fraction;

[0049] (5) Apply the lowest part of the igniter flame to the top surface of the sample. If necessary, cover the entire top surface, but do not let the flame face the vertical surface or edge of the sample. Apply the flame for 30 seconds and remove it every 5 seconds. When removing it, there is just enough time to observe whether the entire top surface of the sample is in a burning state. After each additional 5 seconds, observe that the entire top surface of the sample continues to burn. Immediately remove the igniter. At this time, the sample is ignited and the burning time and observation of the burning length begin.

[0050] Working principle:

[0051] Start the power switch, and under the control of the PLC system, the driving motor 81 starts to work to drive the screw rod 82 to rotate, so that the nut 83 drives the support block 71 to move along the axial direction of the screw rod 82, and under the action of the connecting plate 72, the lifting frame 5 is lowered to the lowest point; then the combustion tube 4 is inserted into the placement groove 51 from top to bottom, at this time, the lower end of the combustion tube 4 is embedded in the base 2, and the retaining ring 41 is located above the support plate 52; the driving motor 81 rotates in the opposite direction, driving the lifting frame 5 to rise to the highest point, so that the lower end of the combustion tube 4 is separated from the base 2 and is at a certain distance from it; the sample is vertically installed at the center position of the combustion tube 4 through the sample clamp 3, and then the lower end of the combustion tube 4 is inserted into the base 2 again, and the mixed gas is passed into the combustion tube 4 through the diffuser ring using an external gas source and a measurement control device, and then the igniter is inserted from the top of the combustion tube 4 to ignite the sample until the subsequent measurement work is completed.

[0052] The above is based on the ideal embodiment of the utility model. Through the above description, relevant personnel can make various changes and modifications without deviating from the technical concept of the utility model. The technical scope of this utility model is not limited to the content in the specification, and the technical scope must be determined according to the scope of the claims.

Claims

1. An oxygen index testing device, comprising a base (2), a combustion tube (4), and a sample clamp (3) arranged inside the base (2), one end of the combustion tube (4) is embedded in the base (2), and the sample clamp (3) is located on the inner side of the combustion tube (4), characterized in that: A lifting frame (5) capable of clamping the combustion cylinder (4) is provided on one side of the base (2), and a driving mechanism for driving the lifting frame (5) away from the base (2) is provided on one side of the combustion cylinder (4).

2. The oxygen index testing device according to claim 1, characterized in that: A placement groove (51) for placing the combustion tube (4) is provided on one side of the lifting frame (5), and a protruding support plate (52) is provided on the side wall of the placement groove (51); a retaining ring (41) is sleeved on the outside of the combustion tube (4), and the bottom surface of the retaining ring (41) can fit with the top surface of the support plate (52).

3. The oxygen index testing device according to claim 2, characterized in that: The driving mechanism comprises a bottom plate (1) for mounting the base (2), a mounting plate (6) being fixedly mounted on the bottom plate (1), a support block (71) and a linear module for driving the support block (71) to move up and down being arranged on one side of the mounting plate (6), and the support block (71) and the lifting frame (5) are connected via a connecting plate (72).

4. The oxygen index testing device according to claim 3, characterized in that: The support block (71) is located on a side of the mounting plate (6) opposite to the lifting frame (5), the connecting plate (72) is fixedly mounted on the end of the support block (71), and one end of the connecting plate (72) bypasses the mounting plate (6) and is fixedly connected to the lifting frame (5).

5. The oxygen index testing device according to claim 4, characterized in that: The linear module comprises a screw rod (82) parallel to the combustion tube (4), the screw rod (82) being rotatably mounted on a side of the mounting plate (6) close to the support block (71), and a nut (83) being screwed onto the screw rod (82), the nut (83) being fixedly connected to the support block (71).

6. The oxygen index testing device according to claim 5, characterized in that: A guide rail (84) is fixedly mounted on one side of the mounting plate (6) close to the support block (71), a slider (85) is fixedly mounted on the support block (71), the guide rail (84) is parallel to the screw rod (82), and the guide rail (84) and the slider (85) are slidably connected.

7. The oxygen index testing device according to claim 6, characterized in that: A shell (11) is installed on the bottom plate (1), and the shell (11) is arranged to cover the outer sides of the linear module and the base (2). The shell (11) is provided with guide grooves (12) on a side close to the lifting frame (5), the number and position of which correspond to those of the connecting plate (72), and the connecting plate (72) passes through the guide grooves (12) to be connected to the lifting frame (5).

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