CN212514871U - Ternary distribution spark test device and test system - Google Patents

Abstract

The utility model discloses a ternary distribution spark test device and a test system, wherein the test system comprises an oxygen analyzer, a flow controller, a ternary distribution spark test device, a gas circuit control valve, a filter and a control unit; the gas circuit control valve and the flow controller are sequentially arranged on an air inlet pipe between the gas cylinder and the ternary distribution spark test device, the oxygen analyzer is arranged on an air outlet pipe of the ternary distribution spark test device, the output end of the oxygen analyzer, the filter and the control unit are sequentially connected, and the control unit is further connected with the gas circuit control valve. The utility model discloses a ternary distribution intrinsic safety spark test device. The device realizes a ternary simultaneous gas distribution mode for hydrogen, air and oxygen and adopts an automatic-manual combined control mode, thereby solving the problems that only binary gas distribution can be realized and the gas distribution mode is single; meanwhile, the device can test a circuit outputting 3-10A current by improving tungsten wires, cadmium discs and other parts.

Description

Ternary distribution spark test device and test system

Technical Field

The utility model relates to an explosion-proof spark test technical field, concretely relates to ternary distribution spark test device, test system.

Background

In the spark test, the safety spark test devices of different countries are different, so that the data are mutually contradictory. In the early 70 s, the spark testing device in germany was recommended by the International Electrotechnical Commission (IEC) as a standard spark testing device, and at present, the safety spark testing device of the IEC standard is still adopted in each member country in the world.

The anti-explosion inspection institutions in China also research and develop intrinsically safe spark devices in many times, wherein the research and the development of Chongqing coal academy and Shanghai anti-explosion inspection stations are the main points. In GB3836.4-2010 explosive environment part 4: in the devices protected by intrinsically safe "i", for spark testing of intrinsically safe devices, a certain safety factor is required, and two methods for increasing the safety factor are mentioned in the above standards: in the case of experiments, the safety factor can be increased by increasing the voltage or current or, if this is not the case, can be met by using more severe explosive test mixtures.

Based on the current situation of the intrinsic safety spark test device at home and abroad, no matter which intrinsic safety spark test device is, certain limitations exist:

(1) only binary gas distribution can be realized; the intrinsic safety spark test device can only carry out binary gas distribution, so that when intrinsic safety equipment is tested and detected, a circuit must be modified to meet the requirement of the standard on the safety coefficient, time and labor are wasted, and the test period is prolonged.

(2) The gas distribution mode is single, and various requirements cannot be met; according to the investigation condition, the gas distribution system of the intrinsic safety spark test device used by each inspection mechanism at present is flow gas distribution or pressure gas distribution, the flow gas distribution is suitable for automatic gas distribution, and the defect that the gas distribution is accurate but the speed is slow is caused; the pressure gas distribution is suitable for manual gas distribution and has the defects of high speed and low precision.

(3) The current range of the test circuit is limited to 0-3A: in the detection process of the high-current intrinsically safe device, high temperature is generated between the tungsten filament and the grating disc to influence the accuracy of the test, so that the intrinsically safe device comprising an intrinsically safe spark experimental device produced in Hungary and a detection device independently developed by domestic detection institutions can only detect intrinsically safe devices with currents within the range of 0-3A, and cannot detect circuits with currents of 3-10A. Especially, the output current of the Power-i Power supply system researched by the German PTB is larger than 3A, and the detection equipment loses value.

Based on the above problems, there is an urgent need in the industry to develop a ternary distribution intrinsic safety spark test device or system capable of automatic-manual hybrid control.

SUMMERY OF THE UTILITY MODEL

The utility model aims at overcoming the deficiencies of the prior art, and providing a ternary distribution spark test device and a test system which can realize automatic-manual hybrid control and can test a circuit outputting 3-10A current.

The purpose of the utility model is realized through the following technical scheme:

a three-way valve spark test apparatus comprising: the explosion-proof device comprises an explosion-proof shell, a bottom plate and an electrode assembly for generating closed sparks and open sparks in an explosive test mixture; the electrode assembly comprises a tungsten filament, a pole holder, a first conductive screw, a second conductive screw, a cadmium disc, a transmission gear, a motor, a first current input piece and a second current input piece; the explosion-proof shell is fixed on the bottom plate, the explosion-proof shell and the bottom plate form a cavity capable of containing an explosive test mixture, the bottom plate is provided with an air inlet and an air outlet, the tungsten filament, the electrode holder, the cadmium disc, the upper end of the first conductive screw rod and the upper end of the second conductive screw rod are all arranged in the cavity, the electrode holder is fixed at the upper end of the first conductive screw rod, the tungsten filament which vertically faces downwards is arranged at the bottom of the electrode holder, and the cadmium disc is fixed at the upper end of the second conductive screw rod; the electrode holder, the tungsten wire and the cadmium disc form a group of electrodes; the middle part of the second conductive screw and the middle part of the first conductive screw are fixed on the transmission gear, the lower end of the first conductive screw is connected with the motor, and one end of the first current input piece is connected with the first conductive screw; one end of the second current input piece is connected with the second conductive screw rod.

Preferably, the method further comprises the following steps: the device comprises a bearing plate, a clamp and an insulating plate; the insulation board is fixed at the lower extreme of clamp, and the flameproof housing loops through under bearing plate, the clamp of clamping bolt fixed clamp, and the clamp is all passed at the both ends of bottom plate, can dismantle with the clamp and be connected.

Preferably, the method further comprises the following steps: the first insulating support piece, the second insulating support piece, a first insulating bolt for fixing the first current input piece and a second insulating bolt for fixing the second current input piece are arranged on the first insulating support piece; the first insulating bolt and the second insulating bolt are fixed on the insulating plate; the first conductive screw penetrates through the bottom plate and is fixed through the first insulating support; the second conductive screw penetrates through the bottom plate and is fixed through the second insulating support piece.

Preferably, the number of the tungsten wires is 4, 4 tungsten wires are fixed on a polar grip with the circumference diameter of 50mm, the distance between the polar grip and the cadmium disc is 10mm, and the second conductive screw and the first conductive screw which respectively drive the cadmium disc and the polar grip are separated by 31 mm.

Preferably, the explosion-proof shell is a metal explosion-proof shell, and the volume of the metal explosion-proof shell is 250cm³And an explosion container capable of withstanding an explosion impact pressure of 1.5MPa or more.

Preferably, the top of the metal explosion-proof shell is provided with a glass transparent part for observing the internal structure of the device.

A test system based on the ternary distribution spark test device comprises: the device comprises an oxygen analyzer, a flow controller, a ternary distribution spark test device, a gas circuit control valve, a filter and a control unit; the gas circuit control valve, flow controller set gradually in the intake pipe between gas cylinder and the ternary distribution spark test device, oxygen analyzer sets up on the outlet duct of ternary distribution spark test device, oxygen analyzer's output, the wave filter, the control unit connects gradually, the control unit still is connected with the gas circuit control valve, wherein the gas cylinder, the gas circuit control valve, the quantity of flow controller is N, each gas cylinder, the gas circuit control valve, flow controller forms distribution all the way, N way gas mixes the intake pipe of back input ternary distribution spark test device.

Compared with the prior art, the utility model have following advantage:

the utility model discloses a ternary distribution intrinsic safety spark test device. The device realizes a ternary simultaneous gas distribution mode for hydrogen, air and oxygen and adopts an automatic-manual combined control mode, thereby solving the problems that only binary gas distribution can be realized and the gas distribution mode is single; meanwhile, the device can test a circuit outputting 3-10A current by improving tungsten wires, cadmium discs and other parts.

Drawings

The accompanying drawings, which form a part of the present application, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is the structure diagram of the ternary distribution spark test device of the utility model.

Fig. 2 is a schematic block diagram of the testing system of the present invention.

The device comprises 1-an insulating plate, 201-a first current input part, 202-a second current input part, 301-a first insulating bolt, 302-a second insulating bolt, 401-a first insulating support part, 402-a second insulating support part, 5-an air inlet, 6-a bottom plate, 7-tungsten wires, 8-pole grips, 9-clamping bolts, 10-a pressure bearing plate, 11-a clamp, 12-an explosion-proof shell, 13-a cadmium disc, 14-an insulating pad, 15-an air outlet, 16-a transmission gear, 17-an insulating connector, 18-a motor, 19-a first conductive screw and 20-a second conductive screw.

Detailed Description

The present invention will be further explained with reference to the drawings and examples.

Referring to fig. 1, a three-way valve spark test apparatus includes: the explosion-proof shell 12, the bottom plate 6 and an electrode assembly for generating closed sparks and open sparks in the explosive test mixture; the electrode assembly comprises a tungsten wire 7, a pole grip 8, a first conductive screw 19, a second conductive screw 20, a cadmium disc 13, a transmission gear 16, a motor 18, a first current input part 201 and a second current input part 202; the explosion-proof shell 12 is fixed on the bottom plate 6, the explosion-proof shell 12 and the bottom plate 6 form a cavity capable of containing an explosive test mixture, the bottom plate 6 is provided with an air inlet 5 and an air outlet 15, the tungsten filament 7, the polar grip 8, the cadmium disc 13, the upper end of the first conductive screw 19 and the upper end of the second conductive screw 20 are all arranged in the cavity, the polar grip 8 is fixed at the upper end of the first conductive screw 19, the tungsten filament 7 which vertically faces downwards is arranged at the bottom of the polar grip 8, and the cadmium disc 13 is fixed at the upper end of the second conductive screw 20; the electrode holder 8, the tungsten filament 7 and the cadmium disc 13 form a group of electrodes; the middle part of the second conductive screw 20 and the middle part of the first conductive screw 19 are both fixed on the transmission gear 16, the lower end of the first conductive screw 19 is connected with the motor 18, and one end of the first current input part 201 is connected with the first conductive screw 19; one end of the second current input 202 is connected to the second conductive screw 20.

Wherein, binary distribution refers to the mixing of combustible gas and air; ternary gas distribution refers to the addition of one way of gas distribution, i.e., the mixing of combustible gas, air and oxygen.

In this embodiment, the three-way valve spark test device further includes: the pressure bearing plate 10, the clamp 11 and the insulating plate 1; the insulating plate 1 is fixed at the lower end of the clamp 11, the flameproof housing 12 is fixed below the clamp 11 sequentially through the bearing plate 10 and the clamping bolt 9, and the two ends of the bottom plate 6 penetrate through the clamp 11 and are detachably connected with the clamp 11.

In this embodiment, the three-way valve spark test device further includes: a first insulating support 401, a second insulating support 402, a first insulating bolt 301 for fixing the first current input member 201, a second insulating bolt 302 for fixing the second current input member 202; the first insulating bolt 301 and the second insulating bolt 302 are fixed on the insulating plate 1; the first conductive screw 19 passes through the bottom plate 6 and is fixed by a first insulating support 401; the second conductive screw 20 passes through the bottom plate 6 and is fixed by the second insulating support 402. The ternary distribution spark test device further comprises: insulating pads 14 and 17-insulating connectors. The flameproof housing 12 is fixed on the base plate 6 by an insulating pad 14. The electric motor 8 rotates the transmission gear 16 via the insulating connector 17.

In this embodiment, the number of the tungsten filaments 7 is 4, 4 tungsten filaments 7 are fixed on the electrode holder 8 with a circumference diameter of 50mm, the distance between the electrode holder 8 and the cadmium disk 13 is 10mm, and the second conductive screw 20 and the first conductive screw 19 which respectively drive the cadmium disk 13 and the electrode holder 8 are separated by 31 mm. The explosion-proof shell 12 is a metal explosion-proof shell, and the metal explosion-proof shell is an explosion container with the volume of 250cm3 and capable of bearing the explosion impact pressure of more than 1.5 MPa. The top of the metal explosion-proof shell is provided with a glass transparent part for observing the internal structure of the device.

Referring to fig. 2, a test system based on the three-way distribution spark test device comprises: the device comprises an oxygen analyzer, a flow controller, a ternary distribution spark test device, a gas circuit control valve, a filter and a control unit; the gas circuit control valve, flow controller set gradually in the intake pipe between gas cylinder and the ternary distribution spark test device, oxygen analyzer sets up on the outlet duct of ternary distribution spark test device, oxygen analyzer's output, the wave filter, the control unit connects gradually, the control unit still is connected with the gas circuit control valve, wherein the gas cylinder, the gas circuit control valve, the quantity of flow controller is N, each gas cylinder, the gas circuit control valve, flow controller forms distribution all the way, N way gas mixes the intake pipe of back input ternary distribution spark test device. In this embodiment, N is 3, and ternary distribution is realized.

The experimental principle of the test system of the scheme is as follows:

gas flows out after entering a mixing tank of the ternary distribution spark test device after passing through the gas circuit control valve and the flow controller, enters an oxygen analyzer for sampling, an electric signal generated by sampling enters a control unit after being filtered by a filter, and the control unit provides a feedback signal to the gas circuit control valve after processing and analyzing the electric signal, so that the opening degree of the gas circuit valve is controlled.

A flow controller is arranged in front of the air inlet end of the ternary distribution spark test device, and the flow controller calculates the volume of gas entering the shell of the ternary distribution spark test device, so that the ternary simultaneous distribution of hydrogen, air and oxygen is realized. For example, 1L of oxygen, 1L of air and 2L of combustible gas can be calculated. The flow ratio mixing method is one of dynamic gas distribution methods, and is to prepare standard gas by strictly controlling the flow of combustible gas and combustion-supporting gas in a certain proportion and mixing them. Compared with the preparation of bottled standard gas (gas with prepared mixed gas concentration), the method can prepare various standard gases with different component contents meeting the requirements on the same gas distribution device, and is particularly suitable for preparing low-content standard gas required by tests. And an air path control valve is also arranged in front of the air inlet end of the ternary distribution spark test device. On one hand, the air path control valve can be manually adjusted to control the air inlet speed; on the other hand, the control unit processes and analyzes the sampled electric signal and then provides a feedback signal to the gas circuit control valve, the opening of the gas inlet valve is dynamically adjusted, the gas circuit control valve is automatically adjusted, automatic-manual mixed control is finally realized, and the problems that the existing intrinsic safety spark experimental device can only realize binary gas distribution and the gas distribution mode is single are solved.

According to the scheme, the diameter of the tungsten wire 7 is changed from 0.2mm to 0.37mm-0.43mm, the free length of the tungsten wire 7 is shortened to 10.5mm, and the abrasion of the cadmium disc 13 can be reduced by shortening the net length of the tungsten wire 7. When the tungsten filament 7 rotates to contact with the cadmium disc 13, the spark test device is short-circuited; at this time, the external circuit, the first current input member 201, the first conductive screw 19, the electrode holder 8, the tungsten filament 7, the cadmium disc 13, the second conductive screw 20, the second current input member 202, and the external circuit form a closed loop circuit. At this time, the total resistance of the device, including the commutation contact resistance (the resistance when the tungsten filament 7 and the cadmium disc 13 are in contact) is reduced to less than 10m Ω, which is the same as the method of increasing the contact area and reducing the contact resistance when the brush type of the automobile manufacturing industry is used in combination with the brass bush on the device shaft. The diameter of tungsten filament 7 increases and can reduce resistance, flows through bigger electric current, and self generating heat also can reduce, and the heat effect increases, causes minimum ignition current to reduce, improves the device ability of igniting, avoids the test result inefficacy that the ignition of red-hot temperature leads to. The total inductance of the test apparatus and the inductance of the connection to the circuit under test must be minimized and not exceed 1 muH.

A testing method of the testing system comprises the following steps:

s1, preparing gas with preset standard concentration; preparing gas with standard concentration, and the specific data are shown in tables 1 and 2;

s2, inputting the gas into the ternary distribution spark test device, electrifying the spark test device and carrying out the spark test; if the gas is detonated, the test is passed, step S3 is executed, if the gas is not detonated, the gas solubility is calibrated, and step S2 is executed; specifically, step S2 includes: connecting two ends of an external circuit to the other end of the first current input member 201 and the other end of the second current input member 202 respectively; the number of revolutions of the motor 18 is set according to an external circuit; the electrode and the cadmium disc 13 are driven to rotate by the first conductive screw rod 19 and the second conductive screw rod 20 respectively, and through the relative motion between the tungsten filament 7 and the cadmium disc 13, a circuit in the spark test device is continuously switched on and off to generate arc sparks, so that whether the energy of the arc sparks can ignite combustible gas in the shell is detected.

Wherein calibrating the gas solubility comprises: the gas solubility was calibrated using the specified calibration current levels, see tables 1 and 2.

In this embodiment, since the tungsten filament 7 is fixed on the electrode holder 8, it rubs against the cadmium disc 13 by the rotation of the first conductive screw 19. Therefore, step S2 further includes: when the tungsten filament 7 is contacted with the cadmium disc 13, the spark test device has short circuit; when the tungsten filament 7 is separated from the cadmium disc 13, the spark test device is open-circuited; setting the number of revolutions of the motor 18 according to the external circuit includes: if the external circuit is a DC circuit, the rotation speed of the motor 18 is 400 r/5 min, and each polarity is 200 r; if the external circuit is an alternating current circuit, the revolution of the motor 18 is 1000 revolutions/12.5 min; if the external circuit is a capacitor circuit, the motor 18 rotates at 400 rpm/5 min with 200 revolutions per polarity.

And S3, after the spark test is finished, replacing gas in the ternary distribution spark test device by using compressed air, and discharging tail gas generated by internal explosion to the outside.

The technical indexes of the scheme comprise the following steps:

1. at two ends of the electrode structure, the self capacitance of the test device (ternary distribution spark test device) when the electrode is open circuit should not exceed 30pF (under the test conditions of 1V 1000Hz and 1.5 MHz), the resistance under 1A direct current should not exceed 0.15 omega when the electrode is closed, and the self inductance should not exceed 3 muH (under the test conditions of 1V 1000Hz and 1.5 MHz).

2. Sensitivity of spark device (ternary distribution spark test device): the spark testing device should operate in a 24V dc circuit switched in with a 95 (+ -5) mH air coil. The circuit should be set according to the current set-point in the corresponding class of calibration circuits in table 7 and table 8 of GB 3836.4-2010. In the spark test device, the electrode holder 8 is connected with the positive electrode and rotates for 440 revolutions, and if ignition of explosive mixture occurs, the sensitivity of the device is considered to be qualified.

3. Gas concentration: the spark test device distributes gas according to the gas concentration given values of corresponding categories in the tables 1 and 8 of GB3836.4-2010, and whether the measured actual gas concentration is consistent with the set value or not is determined.

4. 8-disk rotation speed (tolerance: 0-10%) is held by the spark test device:

(a) for a DC circuit, 400 revolutions (5min), 200 revolutions per polarity;

(b) for an alternating current circuit, 1000 revolutions (12.5 min);

(c) for the capacitive circuit, 400 revolutions (5min), 200 revolutions per polarity. The charging time of the capacitor (capacitor charging time is about 20 ms);

(d) the actual rotational speed of the motor 18 may be adjusted by a program.

5. Mechanical size: four tungsten filaments 7 are fixed on a pole grip 8 with the circumference diameter of 50mm, the distance between the pole grip 8 and a cadmium disc 13 is 10mm, and the distance between two shafts for driving the cadmium disc 13 and the pole grip 8 is 31 mm.

6. Tungsten wire 7: the diameter is 0.37-0.43 mm.

7. For circuits with test currents of 3-10A. The total resistance of the device (ternary distribution spark test device) including the commutation contact resistance (resistance when the tungsten filament 7 and the cadmium disc 13 are in contact) should be reduced to less than 10m omega, and the total inductance of the test device and the inductance of the connecting wire with the tested circuit must be minimized and not exceed 1 muH.

The ternary distribution spark test device has the following functions:

(1) the device can detect the intrinsic safety performance of intrinsic safety circuits of various mining and factory explosion-proof electrical equipment.

(2) The device should be capable of testing and calibrating after the test parameters are set.

(3) The device can realize three-way gas distribution, namely three gases can be automatically proportioned in real time at one time, and the connected gas sources must comprise hydrogen (H2), methane (CH4), propane (C3H8), ethylene (C2H4), oxygen (O2) and AIR (AIR).

(4) The device should be closed-loop gas distribution in real time in each test process to ensure the concentration of the mixed gas, the gas distribution time is as short as possible, and the concentration of hydrogen, oxygen, methane, propane and ethylene should be accurately displayed in real time in the gas distribution process. The hydrogen (or methane, propane, ethylene) concentration and the oxygen concentration are displayed in the ternary distribution, and only the hydrogen (or methane, propane, ethylene) concentration is displayed in the binary distribution.

(5) The device can monitor the whole test process in real time, and can display the action flow chart and various key data of the whole test on a computer screen.

(6) The device realizes the control functions of exhaust, vacuum pumping, gas distribution, concentration control, concentration measurement, spark test, ignition judgment, main electrode revolution counting and the like, and automatically stops when being ignited and displays the revolution value.

(7) The device can measure and display the voltage and current parameters of the calibration circuit and the tested circuit. The external circuit is provided with a direct current switching power supply, and a voltmeter and an ammeter which can display output voltage and current are arranged in the external circuit.

(8) The device can complete the whole test process without starting a computer if a tester does not need to monitor the whole test process in real time.

(9) The device can automatically calculate the revolution number of each polarity according to the total revolution number specified by different tested equipment characteristics, and the polarity change and the calculation of the test revolution number required by each polarity are automatically realized in the test process. The motor 18 revolution counter may be set to a fixed number of revolutions and the motor 18 stopped. The motor 18 has a rotary encoder that counts the number of revolutions of the motor 18.

(10) The device can print the detection result, has real and reliable data, and is convenient for looking up afterwards.

(11) Except for special description, the tolerance of mechanical dimension of the machined part of the device is required to be +/-2.0 percent, the tolerance of the length and the diameter of the tungsten wire 7 is required to be +/-10 percent, and the tolerance of voltage and current is required to be +/-1.0 percent.

(12) The device console is attractive and elegant in appearance, reasonable in layout and arrangement of internal devices, clear and tidy in trend of gas circuits and lines and convenient to maintain. The buttons and the switches on the table top are simple and reasonable in design and convenient to operate.

(13) The device control console consists of an explosion container, a calibration circuit, a PLC, an industrial personal computer, a vacuum pump, a gas concentration controller, an explosion-proof electromagnetic valve, various sensors, various digital instruments and the like.

(14) The device is characterized in that tested voltage, tested current, calibration current, test rotating speed, test revolution, explosion container pressure, hydrogen concentration, oxygen concentration, methane concentration, propane concentration and ethylene concentration are digitally displayed on a control console of the device, and the device is required to be high in display precision and fast in real-time refreshing.

(15) The device control console is provided with a binary test selection, a ternary test selection, a safety coefficient selection, a tested and calibrated selection device, a calibrated type selection switch, ignition, tested and calibrated indicator lamps, a power supply, an air inlet and a rotary button, and a potentiometer for adjusting the rotating speed of the motor 18.

(16) A large-screen display of more than 22# must be embedded in the device console for displaying a dynamic flow chart of the test process and various key data.

The ternary distribution spark test device has the following requirements on the adaptability to the use environment:

ambient temperature: 20 +/-15 DEG C

The ambient humidity is less than or equal to 95 percent RH

Atmospheric pressure: 86 to 110kPa

The performance of the ternary distribution spark test device is as follows:

(1) explosive container

The explosive container generally meets the requirements of GB3836.4-2010 standard annex B.

A group of electrodes are arranged in the explosion container, one is a rotary cadmium disc 13 with two grooves, and the other is a pole holder 8 consisting of four tungsten wires 7.

The explosion container is made of two materials, namely stainless steel and transparent organic glass, and both can bear the explosion pressure of 1500 kPa.

Volume of explosive container is 250cm³The thickness of the container is 6mm plus or minus 0.5mm (stainless steel) and 9.5mm plus or minus 0.5mm (transparent organic glass).

The free length of the tungsten wire 7 of the explosion container is 11mm, and the diameter is divided into 0.2mm and 0.4 mm.

The explosion vessel tungsten wire 7 is fixed to a holder 8 made of brass and having a circumferential diameter of 50 mm.

The distance between the explosion container pole grip 8 and the cadmium disc 13 should be 10mm, the two axes driving the cadmium disc 13 and the pole grip 8 should be 31mm apart, and the two axes must be insulated from each other and the chassis of the test apparatus.

The current of the explosion container flows in and out through a sliding electrode on the shaft system.

Two shafts of the explosion container are meshed by a non-conductive gear, and the gear transmission ratio is 50: 12.

The self capacitance across the electrode structure of the explosion container does not exceed 30pF when the electrode is open.

When the two ends of the electrode structure of the explosion container are closed, the resistance is not more than 0.15 omega under 1-3A direct current, and the resistance is not more than 0.01 omega under 3-10A direct current.

When the two ends of the electrode structure of the explosion container are closed, the self inductance does not exceed 3 muH under the direct current of 1-3A, and the self inductance does not exceed 1 muH under the direct current of 3-10A.

(2) Device sensitivity calibration

The device should adopt 24V voltage to calibrate the sensitivity, and the calibration loop inductance is 95 (+/-5) mH. The device can adjust the calibration loop current to the following values according to different safety factors and equipment types (I, IIA, IIB, IIC).

And the current is regulated to be 110-111 mA when the safety coefficient of the class I equipment is 1.0 time.

The rated current is 100-101 mA when 1.0 time of safety coefficient of IIA equipment

The rated current is 65-66 mA when the safety coefficient of IIB equipment is 1.0 time

The rated current is 30-30.5 mA when the safety coefficient of the IIC type equipment is 1.0 time

And the rated current is 73-74 mA when the safety coefficient of the class I equipment is 1.5 times.

The rated current is 66-67 mA when 1.5 times of safety coefficient of IIA equipment

The rated current is 43-44 mA when 1.5 times of safety coefficient is given to IIB type equipment

The rated current is 20-21 mA when the safety coefficient of the IIC type equipment is 1.5 times

(3) And (3) controlling the revolution number:

the rotational speed of the device pole grip 8 is typically set at 80rpm, but can be adjusted for different types of test circuits.

The test revolution for a dc circuit is 400 revolutions (5min) with a tolerance of 0% to + 10% for 200 revolutions per polarity.

The test revolution for the ac circuit is 1000 revolutions (12.5min) with a tolerance of 0% to + 10%.

The experimental number of revolutions for the capacitive circuit was 400 revolutions (5min), with a tolerance of 0% to + 10% for each polarity of 200 revolutions. And the capacitor must be ensured to have enough charging time which is not less than 3 times of time constant, the normal charging time is about 20ms, when the charging time is not enough, the device can slow down the rotating speed of the driving motor 18 of the spark testing device, and the testing time is increased, so that the testing rotating number is not changed to keep the same spark number.

(4) And (4) safety factor:

the device can adopt 1.0 time or 1.5 times of safety factor to test the test circuit, and the purpose of adopting 1.5 times of safety factor to test is to ensure that the type test and evaluation are carried out under the condition of the circuit which is easier to ignite together than the original circuit during the test.

For inductance and resistance circuits, the device can obtain 1.5 times of safety factor by reducing the current-limiting resistance value, and also can obtain 1.5 times of safety factor by increasing the current to 1.5 times of fault current by increasing the power supply voltage.

For capacitive circuits, the device should be able to achieve a factor of 1.5 safety by increasing the voltage to 1.5 times the fault voltage. The device can achieve a factor of 1.5 safety by testing the original circuit with a more readily ignitable gas mixture. The device is tested with 1.5 times explosive gas mixture, which is equivalent to 1.5 times safety factor.

(5) Explosive gas mixture

TABLE 1 explosive gas mixture with a safety factor of 1.5 times

TABLE 2 explosive gas mixture with a safety factor of 1.0 times

(6) The test stability of the device is as follows:

the device continuously tests for 5 times according to the sensitivity test condition, and takes full ignition as qualified test gas concentration and current.

(7) Tungsten filament 7 fusing device:

the tungsten wire 7 is required to be conveniently and quickly fused, and the end part is prevented from cracking and pilling.

5.2 the main technical indexes are as follows:

(1) explosive container volume 250cm3

(2) The explosive container is subjected to pressure: 1.5MPa

(3) Diameter of tungsten filament 7: phi 0.2mm +/-0.02 mm (under 1-3A direct current),

Phi 0.40 +/-0.03 mm (under 3-10A direct current)

(4) The internal resistance of the device is less than or equal to 0.15 omega (under 1-3A direct current)

Less than or equal to 10m omega (under 3 to 10A direct current)

(5) The self inductance of the device is less than or equal to 3 mu H (under 1-3A direct current)

Less than or equal to 1 mu H (under 3 to 10A direct current)

(6) Device self-capacitance is less than or equal to 30pF (open circuit state)

(7) Test ignition signal pressure or light

(8) Test rotating speed: is adjustable at 0-120 r/min

(9) And (3) counting in the test: 0 to 400r (DC test), 0 to 1000r (AC test)

(10) Test voltage: 0 to 300V

(11) Test current: 0 to 10A

(12) Inductance of test inductance circuit is less than or equal to 1.0H

(13) Frequency of test circuit is less than or equal to 1.5MHz

(14) The test qualification criterion is as follows: the mixed gas is ignited for 5 times

(15) The air intake quantity is as follows: binary or ternary gases

(16) The air inlet pressure: 0.05 to 0.15MPa (0.1 MPa is recommended)

(17) And (3) distribution accuracy: plus or minus 0.5 percent

(18) The gas distribution time is less than or equal to 180 seconds (when the container is 250 cm)³)

In conclusion, the scheme provides a manual integrated ternary distribution spark test device which can test a circuit with the current of 0-10A; the requirement of short gas distribution period and high precision is realized by adopting a gas distribution system controlled by software; and a ternary interconnection gas distribution mode is realized, the modification of a test circuit is avoided, and the inspection efficiency is improved.

The above-mentioned specific implementation is the preferred embodiment of the present invention, can not be right the utility model discloses the limit, any other does not deviate from the technical scheme of the utility model and the change or other equivalent replacement modes of doing all contain within the scope of protection of the utility model.

Claims (7)

1. A three-way valve spark test device is characterized by comprising: the explosion-proof device comprises an explosion-proof shell, a bottom plate and an electrode assembly for generating closed sparks and open sparks in an explosive test mixture; the electrode assembly comprises a tungsten filament, a pole holder, a first conductive screw, a second conductive screw, a cadmium disc, a transmission gear, a motor, a first current input piece and a second current input piece;

the explosion-proof shell is fixed on the bottom plate, the explosion-proof shell and the bottom plate form a cavity capable of containing an explosive test mixture, the bottom plate is provided with an air inlet and an air outlet, the tungsten filament, the electrode holder, the cadmium disc, the upper end of the first conductive screw rod and the upper end of the second conductive screw rod are all arranged in the cavity, the electrode holder is fixed at the upper end of the first conductive screw rod, the tungsten filament which vertically faces downwards is arranged at the bottom of the electrode holder, and the cadmium disc is fixed at the upper end of the second conductive screw rod; the electrode holder, the tungsten wire and the cadmium disc form a group of electrodes; the middle part of the second conductive screw and the middle part of the first conductive screw are fixed on the transmission gear, the lower end of the first conductive screw is connected with the motor, and one end of the first current input piece is connected with the first conductive screw; one end of the second current input piece is connected with the second conductive screw rod.

2. The three-way valve timing spark test apparatus of claim 1, further comprising: the device comprises a bearing plate, a clamp and an insulating plate;

the insulation board is fixed at the lower extreme of clamp, and the flameproof housing loops through under bearing plate, the clamp of clamping bolt fixed clamp, and the clamp is all passed at the both ends of bottom plate, can dismantle with the clamp and be connected.

3. The three-way valve timing spark test apparatus of claim 2, further comprising: the first insulating support piece, the second insulating support piece, a first insulating bolt for fixing the first current input piece and a second insulating bolt for fixing the second current input piece are arranged on the first insulating support piece; the first insulating bolt and the second insulating bolt are fixed on the insulating plate; the first conductive screw penetrates through the bottom plate and is fixed through the first insulating support; the second conductive screw penetrates through the bottom plate and is fixed through the second insulating support piece.

4. The three-element distribution spark test device according to claim 1, wherein the number of tungsten wires is 4, 4 tungsten wires are fixed on a pole grip with a circumference diameter of 50mm, the distance between the pole grip and the cadmium disc is 10mm, and the second conductive screw and the first conductive screw which respectively drive the cadmium disc and the pole grip are separated by 31 mm.

5. The ternary distribution spark test device of claim 1, wherein the explosion-proof enclosure is a metal explosion-proof enclosure, and the volume of the metal explosion-proof enclosure is 250cm³And an explosion container capable of withstanding an explosion impact pressure of 1.5MPa or more.

6. The ternary distribution spark test device according to claim 1, wherein a glass transparent part for observing the internal structure of the device is arranged at the top of the metal explosion-proof shell.

7. A test system based on the three-way valve timing spark test apparatus of any one of claims 1 to 6, comprising: the device comprises an oxygen analyzer, a flow controller, a ternary distribution spark test device, a gas circuit control valve, a filter and a control unit;

the gas circuit control valve, flow controller set gradually in the intake pipe between gas cylinder and the ternary distribution spark test device, oxygen analyzer sets up on the outlet duct of ternary distribution spark test device, oxygen analyzer's output, the wave filter, the control unit connects gradually, the control unit still is connected with the gas circuit control valve, wherein the gas cylinder, the gas circuit control valve, the quantity of flow controller is N, each gas cylinder, the gas circuit control valve, flow controller forms distribution all the way, N way gas mixes the intake pipe of back input ternary distribution spark test device.

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