Pneumoelectric integrated ignition head device for automatic flash point tester

Abstract

The utility model relates to a pneumoelectric integrated ignition head device for an automatic flash point tester, which comprises an ignition head and a control system, the ignition head comprises an alundum tube, a thermocouple, a gas ignition needle and a silicon nitride ignition head, four through holes are uniformly distributed on the alundum tube, and the thermocouple is arranged in the silicon nitride ignition head. Two wires of the thermocouple, the fuel gas ignition needle and the silicon nitride ignition head are respectively inserted into four through holes of the alundum tube and fixed, the silicon nitride ignition head and the fuel gas ignition needle are on the same horizontal plane, a temperature sensing point of the thermocouple is 5 mm above the fuel gas ignition needle, and combustible gas is guided into the tail end of the fuel gas ignition needle through a gas guide tube. An electromagnetic valve and a fine adjustment needle valve are connected to the gas guide pipe in series, the silicon nitride ignition head is connected into a direct-current power source and connected with a normally-open relay in series, and the electromagnetic valve, the normally-open relay and the thermocouple are all electrically connected with the control system. According to the utility model, gas ignition and electronic ignition can be automatically and freely switched, and the flame size and the electronic ignition aging degree can be detected.

Description

TECHNICAL FIELD

[0001] The utility model relates to oil flash point determination technical field, specifically speaking, it is a gas electricity integrated ignition head device for automatic flash point tester. BACKGROUND

[0002] The flash point refers to the lowest temperature under the prescribed test conditions, the test flame causes the sample vapor to ignite, and the flame spreads to the liquid surface. According to the application of different oil products in various industries, the flash point is a basic index of oil product performance. The flash point is divided into open flash point and closed flash point. The most commonly used determination of the current domestic open flash point and closed flash point is based on the standards of GB / T3536-2008 "Determination of flash and fire point of petroleum products Cleveland open cup method" and GB / T261-2021 "Determination of flash point Bunsen-Martin closed cup method". The test flame required by the two determination methods is gas flame, which refers to the combustion of gas in front of a 0.8mm diameter ignition needle, and the flame diameter is kept at 3.2-4.8mm by a micro-adjusting valve.

[0003] Using gas flame as test flame has obvious disadvantages:

[0004] (1) The basic flash point test is usually carried out in oil product analysis laboratory. There are various flammable substances in the oil product analysis laboratory, and open flame is very dangerous in the oil product laboratory. Many laboratories now clearly stipulate that gas flame cannot be used as test flame;

[0005] (2) The gas flame is greatly affected by the outside world. Because the flame is small, a little air flow may extinguish the flame, resulting in that the flash point cannot be measured during the determination process, and the sample is still heated. Light test is invalid, and heavy sample may cause fire when it reaches the ignition point;

[0006] (3) Gas is usually liquefied gas. The quality of liquefied gas and the gas amount in the gas cylinder may affect the size of the test flame, and the size of the flame directly reflects the temperature of the test flame. Too high and too low temperature will cause the test result to be low and high.

[0007] Because many laboratories clearly stipulate that gas flame cannot be used as test flame, many flash point instrument manufacturers at home and abroad have developed electronic ignition heads, but electronic ignition heads also have obvious disadvantages:

[0008] (1) Electronic ignition head has service life. According to the use frequency and use intensity, the ignition head will age, change the heating area, reduce the temperature, or even not heat at all. Therefore, the flash point may be delayed or not tested during the test process, and the sample may be out of fire when it reaches the ignition point;

[0009] (2) In GB / T261-2021 "Determination of flash point - Pensky-Martens closed cup method", 6.1 mentions "Note: In some cases, the test results of electronic ignition and flame ignition will be different. In case of dispute, unless otherwise specified, the arbitration test is based on the results of manual testing with flame ignition." It can be seen that the flash point value of the electronic ignition head test cannot be used as the arbitration result.

[0010] Although some flash point tester manufacturers have introduced a function of freely switching between gas ignition and electronic ignition, the so-called free switching refers to manually disassembling the original ignition head, replacing it with the required ignition head, and changing the ignition mode from the software to achieve it. This requires higher manual operation ability of the operator, and the installation precision after replacement is also relatively high. Practical new type content

[0011] In view of the above problems, the utility model provides a kind of gas-electric integrated ignition head device for automatic flash point tester, which realizes the free switching between real gas ignition and electronic ignition, and can monitor the size of flame and the aging degree of electronic ignition.

[0012] The utility model discloses a kind of gas-electric integrated ignition head device for automatic flash point tester, which solves the above technical problems, and the technical scheme is as follows: a kind of gas-electric integrated ignition head device for automatic flash point tester, including ignition head and control system, the ignition head includes corundum pipe, thermocouple, gas ignition needle and silicon nitride ignition head, four through holes are uniformly distributed on the corundum pipe along the length direction of pipe, the silicon nitride ignition head includes two wires, the thermocouple, gas ignition needle and the two wires of silicon nitride ignition head are inserted into four through holes of corundum pipe and fixed, the silicon nitride ignition head and gas ignition needle are in the same horizontal plane, the temperature sensing point of the thermocouple is at the top 5mm of gas ignition needle, the length that the thermocouple, gas ignition needle and silicon nitride ignition head stretch out from corundum pipe through hole is 3cm.

[0013] Further, the tail end of the gas ignition needle is introduced into combustible gas through a gas guide pipe, the electromagnetic valve and the needle valve are connected in series on the gas guide pipe along the direction of the introduction of the combustible gas, the electromagnetic valve is controlled by the control system to control the on-off of the gas, the silicon nitride ignition head is connected to the DC power supply and connected in series with the normally open relay, the output end of the normally open relay is electrically connected with the control system, the thermocouple is electrically connected with the control system, and the temperature of the flame of the gas ignition needle or the temperature of the silicon nitride ignition head collected by the thermocouple is transmitted to the control system through the signal.

[0014] Further, the corundum pipe is cylindrical and has an outer diameter of 1-9mm, and the inner diameter of each through hole is 1.8-2.2mm.

[0015] Further, the thermocouple is resistant to temperature above 800 degrees and is packaged by a stainless steel tube, the outer diameter of the stainless steel tube is negative tolerance to the inner diameter of the through hole of the corundum tube, and the temperature sensing point at the front end of the thermocouple extends 5mm out of the stainless steel tube.

[0016] Further, the gas ignition needle is a stainless steel capillary tube with an inner diameter of 0.8-1.0mm, the outer diameter of the stainless steel capillary tube is negative tolerance to the inner diameter of the through hole of the corundum tube, the front end of the stainless steel capillary tube is chamfered for 10mm, the wall thickness of the tip of the stainless steel capillary tube is 0.1mm, and the tip is bent at 5mm to form an angle of 150 degrees with the stainless steel capillary tube.

[0017] Further, the silicon nitride ignition head is packaged by a bare wire, the heating area of the silicon nitride ignition head is a 5mm long area of the tip of the wire, the diameter of the wire in the heating area is 3mm, the rated power of the heating area is 120W, and the diameter of the wire is negative tolerance to the inner diameter of the through hole of the corundum tube.

[0018] Further, the tips of the gas ignition needle and the silicon nitride ignition head are in the same direction with the temperature sensing point of the thermocouple.

[0019] Compared with the prior art, the utility model has the following beneficial effects:

[0020] 1. The utility model can realize automatic and free switching of gas ignition and electronic ignition, can detect the size of the flame and the aging degree of the electronic ignition, and improve the safety factor.

[0021] 2. The utility model ensures that no matter whether gas ignition or electronic ignition is selected, the normal operation of the ignition action in the whole test process, prevents the flame from being extinguished by external air flow disturbance, prevents the silicon nitride ignition head from aging, and avoids the problem that after the sample reaches the flash value, the flash point value cannot be detected, and heating is continued, resulting in a fire event.

[0022] 3. The utility model realizes free switching of gas ignition and electronic ignition through automation, does not need manual adjustment, and is more in line with market demand. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is the structure schematic view of the utility model;

[0024] Figure 2 is the explosion schematic view of the ignition head in the utility model;

[0025] Figure 3 is the structure schematic view of the ignition head in the utility model. DETAILED DESCRIPTION

[0026] The utility model discloses a kind of automatic switching of gas ignition and electronic ignition, as shown in the accompanying drawings, it includes corundum tube, thermocouple, silicon nitride ignition head, gas ignition needle and electronic ignition. Figures 1-3The present invention is described in detail. The exemplary embodiments and descriptions of the present invention are used to explain the present invention but are not intended to limit the present invention.

[0027] An electric-gas integrated ignition head device for an automatic flash point tester includes an ignition head 11 and a control system 5. The ignition head includes a corundum tube 1, a thermocouple 2, a gas ignition needle 3 and a silicon nitride ignition head 4. Figure 3 As shown, the corundum tube is provided with four through holes evenly distributed along the length of the tube. The silicon nitride ignition head includes two wires. The thermocouple, the gas ignition needle and the two wires of the silicon nitride ignition head are respectively inserted into the four through holes of the corundum tube and fixed. The silicon nitride ignition head and the gas ignition needle are at the same horizontal plane. The temperature sensing point of the thermocouple is 5 mm above the gas ignition needle. The length of the thermocouple, the gas ignition needle and the silicon nitride ignition head extending from the through hole of the corundum tube is 3 cm. When the device is installed on the flash point tester, the tips of the gas ignition needle and the silicon nitride ignition head are kept in the same direction as the temperature sensing point of the thermocouple.

[0028] Specifically, if Figure 1 As shown, the tail end of the gas ignition needle is connected to the gas 10 through an air guide pipe, thereby introducing combustible gas. The air guide pipe is connected in series with a solenoid valve 6 and a fine-tuning needle valve 7 in the direction of the combustible gas introduction. The solenoid valve is controlled by the control system to turn the gas on and off, and the fine-tuning needle valve can be used to adjust the size of the flame. The silicon nitride ignition head is connected to a DC power supply 8 and is connected in series with a normally open relay 9. The output end of the normally open relay is electrically connected to the control system, and the on and off of the output end of the normally open relay is controlled by the control system. The thermocouple is electrically connected to the control system. At the same time, the thermocouple collects the flame temperature of the ignition gas needle or the temperature of the silicon nitride ignition head and transmits it to the control system through a signal to determine whether the flame size of the gas ignition needle or the calorific value of the silicon nitride ignition head meets the requirements.

[0029] Specifically, the corundum tube is cylindrical and has an outer diameter of 1-9 mm and an inner diameter of each through hole of 1.8-2.2 mm, and the corundum tube is used to effectively insulate and fix the thermocouple, the gas ignition needle and the silicon nitride ignition head in the device; the thermocouple is resistant to a temperature of 800 degrees or above and is packaged by a stainless steel tube, the outer diameter of the stainless steel tube and the inner diameter of the through hole of the corundum tube are negative tolerances, the stainless steel tube can be just inserted into the corundum tube without being too loose, and the temperature sensing point at the front end of the thermocouple extends 5 mm out of the stainless steel tube; the gas ignition needle is a stainless steel capillary tube and has an inner diameter of 0.8-1.0 mm, the outer diameter of the stainless steel capillary tube is also a negative tolerance with the inner diameter of the through hole of the corundum tube, the stainless steel capillary tube can be just inserted into the corundum tube without being too loose, the front end of the stainless steel capillary tube is chamfered for 10 mm in length, the wall thickness of the tip of the stainless steel capillary tube is 0.1 mm, and the tip is bent at a distance of 5 mm to form an angle of 150 degrees with the stainless steel capillary tube; the silicon nitride ignition head is packaged by bare wires, that is, two wires, the heating area of the silicon nitride ignition head is a 5 mm long area at the tip of the wire, the diameter of the wire in the heating area is 3 mm, the rated power of the heating area is 120 W, and the silicon nitride ignition head is required to reach the maximum power within three seconds, and whether the silicon nitride ignition head is qualified can be tested by whether the maximum power can be reached within three seconds, and the diameter of the wire and the inner diameter of the through hole of the corundum tube are negative tolerances, the wire can just pass through the through hole of the corundum tube.

[0030] In the implementation process, the gas-electric integrated ignition head device provided in the application is installed in the automatic flash point tester, since the temperature sensing point of the thermocouple is directly above the gas ignition needle and close to the heating point of the silicon nitride ignition head, the relative positions of the temperature sensing point and the heating point are fixed, and the thermocouple can stably collect the temperature of the flame of the ignition needle and the temperature of the heating point of the silicon nitride ignition head. Before testing, the gas solenoid valve is manually opened, the flame at the tip of the gas ignition needle is ignited, and the flame size at the tip of the gas ignition needle is adjusted to 3.2-4.8 mm under the condition of no gas flow disturbance by adjusting the needle type valve, the temperature sensing point of the thermocouple is located at the outer flame position of the flame, and the temperature collected by the thermocouple under the condition of no gas flow disturbance is 780-820℃. If the temperature collected by the thermocouple is lower than 780℃, it indicates that the flame is not ignited or the flame size is less than 3.2 mm, and if the temperature collected by the thermocouple is greater than 820℃, it indicates that the flame size is greater than 4.8 mm, and the flame size at the tip of the ignition needle can be adjusted to meet the requirements.

[0031] The gas flame of the gas ignition needle is extinguished, and the silicon nitride ignition head is powered alone, the silicon nitride ignition head reaches the highest temperature within three seconds under the condition of no gas flow disturbance, and the temperature collected by the thermocouple reaches a stable state, the collected temperature is 630-670℃, and under normal circumstances, the temperature will not increase again, and only when the silicon nitride ignition head is aging, the collected temperature will be lower.

[0032] The control system is provided with a valve value for collecting temperature of the thermocouple and issuing error prompt. If the deviation between the temperature collected by the thermocouple and the set temperature reaches the valve value during the working process of the gas-electric integrated ignition head device, the control system will execute a correction action or an error prompt.

[0033] After the automatic flash point tester is started and the gas-electric integrated ignition head device provided by the application enters the working state, the system first determines whether the operator selects gas ignition or electric ignition. When the control system identifies gas ignition, the electromagnetic valve is opened before the sample cup is heated, the gas is sprayed through the front end of the gas ignition needle, the silicon nitride ignition head flame ignition action is started, and the thermocouple continuously detects the temperature of the flame at the tip of the gas ignition needle. If the detected temperature is lower than 780℃, the silicon nitride ignition head will be powered for three seconds to execute the flame ignition action again. If the detected temperature is still lower than 780℃ after the action is executed for three times, the system will give an error prompt: “Please adjust the flame size!” or “Insufficient gas or silicon nitride ignition head failure”. If the detected temperature is continuously higher than 820℃, the system will give an error prompt: “Please adjust the flame size!”

[0034] If the detected temperature is maintained at 800℃±20℃, it is considered that the flame ignition is successful, and then the flame maintaining program is executed during the test process. The thermocouple continuously collects the temperature during the whole test process. Once the temperature continuously decreases, it is judged that the flame is extinguished, and the flame ignition action is executed again.

[0035] When the system identifies electric ignition, the pre-ignition action will be executed before the flash point sample cup is heated. The control system will power the silicon nitride ignition head for three seconds, and the thermocouple detects whether the temperature reaches 650℃±20℃. The thermocouple should collect the highest temperature within three seconds. If the highest temperature reaches 650℃±20℃, it is considered that the ignition head is working normally. If the temperature is lower than the temperature, the ignition action is executed again. If the temperature collected by the thermocouple cannot reach 650℃±20℃ after the ignition action is executed for three times, the system will give an error prompt: “Silicon nitride ignition head failure”.

[0036] After the pre-ignition action is completed, the silicon nitride ignition head is working normally, the automatic flash point tester enters the flash point test process, and waits for the ignition instruction. When the flash point ignition condition is reached, the control system will power the silicon nitride ignition head for three seconds three seconds in advance, and the thermocouple detects whether the highest temperature of the silicon nitride ignition head reaches 650℃±20℃. If the temperature reaches the temperature, it is judged that the silicon nitride ignition head is working normally, and the ignition action is continued. If the temperature is lower than the temperature, the silicon nitride ignition head is powered for three seconds again to execute the ignition action. If the temperature collected by the thermocouple cannot reach 650℃±20℃ after the silicon nitride ignition head is powered for three seconds for three times, the system will give an error prompt: “Silicon nitride ignition head failure”.

[0037] The device ensures normal operation of the ignition action throughout the test process regardless of the selection of gas ignition or electric ignition, prevents external airflow disturbance from extinguishing the flame, prevents the aging of the silicon nitride ignition head, and prevents the occurrence of open fire events caused by continued heating after the sample reaches the flash point value.

[0038] The above describes the technical solutions provided by the embodiments of the present application in detail, and the principles and implementation manners of the embodiments of the present application are described by applying specific examples; the above description of the embodiments is only applicable to helping understand the principles of the embodiments of the present application; meanwhile, for those skilled in the art, the embodiments of the present application will have changes in the specific implementation manners and application ranges, and the above description should not be understood as limiting the embodiments of the present application.

Claims

1. A gas-electric integrated ignition head device for an automatic flash point tester, characterized in that: The invention comprises an ignition head (11) and a control system (5), wherein the ignition head comprises a corundum tube (1), a thermocouple (2), a gas ignition needle (3) and a silicon nitride ignition head (4), wherein the corundum tube is provided with four through holes evenly distributed along the tube length direction, and the silicon nitride ignition head comprises two wires, wherein the thermocouple, the gas ignition needle and the two wires of the silicon nitride ignition head are respectively inserted into the four through holes of the corundum tube and fixed, wherein the silicon nitride ignition head and the gas ignition needle are on the same horizontal plane, the temperature sensing point of the thermocouple is 5 mm above the gas ignition needle, and the length of the thermocouple, the gas ignition needle and the silicon nitride ignition head extending from the through hole of the corundum tube is 3 cm.

2. The gas-electric integrated ignition head device for an automatic flash point tester according to claim 1, characterized in that: The tail end of the gas ignition needle is introduced into the combustible gas through the gas guide pipe. The gas guide pipe is connected in series with a solenoid valve (6) and a fine-tuning needle valve (7) in the direction of the combustible gas introduction. The solenoid valve is controlled by the control system to turn the gas on and off. The silicon nitride ignition head is connected to a DC power supply (8) and is connected in series with a normally open relay (9). The output end of the normally open relay is electrically connected to the control system. The thermocouple is electrically connected to the control system. At the same time, the thermocouple collects the flame temperature of the gas ignition needle or the temperature of the silicon nitride ignition head and transmits it to the control system through a signal.

3. The gas-electric integrated ignition head device for an automatic flash point tester according to claim 1, characterized in that: The corundum tube is cylindrical and has an outer diameter of 1 to 9 mm, and the inner diameter of each through hole is 1.8 to 2.2 mm.

4. The gas-electric integrated ignition head device for an automatic flash point tester according to claim 1, characterized in that: The thermocouple has a temperature resistance of over 800 degrees and is encapsulated by a stainless steel tube. The outer diameter of the stainless steel tube and the inner diameter of the through hole of the corundum tube have a negative tolerance, and the temperature sensing point at the front end of the thermocouple extends 5 mm out of the stainless steel tube.

5. The gas-electric integrated ignition head device for an automatic flash point tester according to claim 1, characterized in that: The gas ignition needle is a stainless steel capillary with an inner diameter of 0.8 to 1.0 mm. The outer diameter of the stainless steel capillary and the inner diameter of the through hole of the corundum tube have a negative tolerance. The front end of the stainless steel capillary is chamfered for 10 mm. The tip of the stainless steel capillary has a wall thickness of 0.1 mm and is bent at 5 mm from the tip to form an angle of 150 degrees with the stainless steel capillary.

6. The gas-electric integrated ignition head device for an automatic flash point tester according to claim 1, characterized in that: The silicon nitride ignition head is a bare wire package. The heating area of ​​the silicon nitride ignition head is the 5mm length area of ​​the wire tip, and the wire diameter of the heating area is 3mm. The rated power of the heating area is 120W. At the same time, the diameter of the wire and the inner diameter of the through hole of the corundum tube have a negative tolerance.

7. The gas-electric integrated ignition head device for an automatic flash point tester according to claim 1, characterized in that: The tips of the gas ignition needle and the silicon nitride ignition head are kept in the same direction as the temperature sensing point of the thermocouple.

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