Device and method for detecting sulfur content in coal tar

Abstract

The invention belongs to the technical field of sulfur content detection, and particularly relates to a device and method for detecting the sulfur content in coal tar. The sample injector is used for conveying coal tar into the cracking pipe; the titration cell is used for measuring the concentration of SO2; the computer is used for collecting and analyzing electric signals of the titration cell; the controller is electrically connected with the sample injector; the cracking pipe is provided with a partition plate and is divided into a combustion chamber and a vaporizing chamber through the partition plate, the vaporizing chamber is communicated with the sample injector, the vaporizing chamber is provided with an electric heating wire, the combustion chamber is communicated with the titration cell, the combustion chamber is provided with an oxygen inlet pipe for inputting oxygen, and the partition plate is provided with a nozzle. According to the scheme, the problem that the temperature in the cracking pipe cannot reach the set temperature due to excessive impurities adhered to the inner wall of the cracking pipe is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of sulfur content detection, and particularly relates to a device and method for detecting sulfur content in coal tar. Background Art

[0002] With the widespread mining of coking coal, low-sulfur coking coal resources are now scarce. To reduce coking costs and expand coking coal resources, coking companies are increasingly using medium- and high-sulfur coal as a raw material for coking. Ensuring that the sulfur content of coke and coal tar meets relevant technical specifications while expanding coking coal resources and increasing the amount of medium- and high-sulfur coal used in coking has become a common concern in the industry.

[0003] In actual coking production, increasing the proportion of medium- and high-sulfur coal will inevitably lead to an increase in the sulfur content in the corresponding gas, liquid, and solid phases of the products, based on the principle of conservation of mass. Coking operators must not only pay attention to the sulfur content in the coke, but also the sulfur content in the gas and liquid phases. Therefore, it is very important to quickly, effectively, and accurately measure the sulfur content distribution in the gas, liquid, and solid phases of coking products.

[0004] Currently, the existing method for online detection of trace sulfur content in high-purity or ultra-pure ammonia, published with publication number CN102798697A, uses a microinjector to quantitatively sample a high-purity ammonia into a cracking tube. Using nitrogen as a protective gas, oxygen is introduced at high temperature to fully combust the sample, converting the sulfur in the high-purity ammonia into sulfur dioxide, thereby separating the sulfur. The sulfur dioxide is then introduced into iodine in a titration cell to undergo a redox reaction. The consumed iodine is replenished by electrolysis of potassium iodide using an electrolytic electrode. Computer software measures the power consumption of the electrolysis, and the sulfur content in the high-purity ammonia sample is calculated based on Faraday's law of electrolysis. This method for determining sulfur content in high-purity ammonia has the advantages of simple operation, no need for special sample treatment, fast analysis speed, high measurement accuracy, and a low detection limit.

[0005] However, there is also a problem: the existing cracking tube is directly burned, and many impurities will remain in the cracking tube, resulting in the external heating heat not being transferred to the inside. Summary of the Invention

[0006] This solution provides a device for detecting the sulfur content in coal tar, which is used to solve the problem that the temperature inside the cracking tube cannot reach the set temperature due to excessive impurities adhering to the inner wall of the cracking tube.

[0007] This solution provides a device for detecting sulfur content in coal tar, comprising: Cracking tube: used for cracking coal tar; Injector: used to transport coal tar into the cracking tube; Titration cell: used to determine the concentration of SO2; Computer: used to collect and analyze the electrical signals from the titration cell; Controller: The controller is electrically connected to the sample injector; The cracking tube is provided with a partition plate, which is divided into a combustion chamber and a vaporization chamber by the partition plate. The vaporization chamber is connected to the sample injector and is provided with a heating wire. The combustion chamber is connected to the titration cell and is provided with an oxygen inlet pipe for inputting oxygen. The partition plate is provided with a nozzle.

[0008] The principle of this scheme is as follows: coal tar is introduced into the vaporization chamber of the cracking tube through an injector. A heating wire is installed inside the vaporization chamber to heat the coal tar, causing it to rapidly vaporize into gas at high temperatures. A partition plate is installed inside the cracking tube, dividing it into two areas: the vaporization chamber and the combustion chamber. A nozzle is installed on the partition plate, allowing the gaseous coal tar from the vaporization chamber to be ejected at high velocity into the combustion chamber. Oxygen is introduced into the combustion chamber through an oxygen inlet pipe, providing sufficient oxidant to completely combust the gaseous coal tar ejected from the nozzle. During this process, the sulfur content in the coal tar is converted into sulfur dioxide (SO2).

[0009] The SO2-containing gas produced by combustion then enters the titration cell, where the SO2 concentration is measured using a specific method (such as microcoulometric titration). A sensor within the titration cell transmits the detected electrical signal to a computer for analysis. The computer collects and analyzes the electrical signal from the titration cell, calculating the SO2 concentration and, further, the sulfur content in the original sample. A controller regulates the operation of the sample injector to ensure accurate and repeatable injection.

[0010] The benefits of this solution are as follows: 1. The partition design prevents incompletely vaporized liquid or impurities from directly entering the combustion chamber, which could cause them to adhere to the combustion chamber walls, preventing the combustion chamber temperature from reaching the set temperature and resulting in incomplete sulfide conversion. 2. Precise control of heating by the heating wire and oxygen supply optimizes combustion conditions, reduces the formation of incomplete combustion products, and thus reduces analytical errors. 3. The nozzle design effectively increases the flow rate of gas entering the combustion chamber, ensuring thorough mixing of the gas and oxygen, thereby improving the sulfur dioxide conversion rate.

[0011] Furthermore, the vaporization chamber is provided with a nitrogen inlet pipe for inputting nitrogen, and the heating wire is arranged on the nitrogen inlet pipe. The heating wire is used to heat the nitrogen, and the heating wire is electrically connected to the controller.

[0012] Nitrogen enters the vaporization chamber through a nitrogen inlet pipe, where it is heated by a heating wire. This heating wire is electrically connected to a controller, which precisely adjusts the heating power to ensure the nitrogen reaches the desired temperature. The heated nitrogen acts as a carrier gas, rapidly bringing the liquid coal tar into the high-temperature zone and promoting its vaporization.

[0013] The presence of nitrogen not only accelerates the vaporization process but also dilutes the coal tar vapor, preventing incomplete combustion or carbon deposition caused by localized excessive concentrations. As an inert gas, nitrogen creates a protective atmosphere within the vaporization chamber, preventing unnecessary oxidation or other side reactions when the coal tar comes into contact with oxygen at high temperatures, thereby reducing impurity formation.

[0014] Furthermore, it also includes a signal amplification unit, which is electrically connected to the titration cell.

[0015] In the titration cell, sulfur dioxide (SO2) generates weak current or voltage signals when it participates in electrochemical reactions. Because these signals are often very small, direct analysis may not be accurate enough. The signal amplification unit amplifies these weak signals to a measurable level. Through the design of the amplification circuit, the ability to detect small changes can be enhanced, resulting in higher-precision measurements. This is particularly important for measuring trace sulfur content, as it is able to distinguish extremely subtle changes. The amplification unit not only amplifies the useful signal but can also be designed with noise suppression capabilities to reduce the impact of background noise on the measurement results, further improving the signal-to-noise ratio (SNR).

[0016] The system further includes a cracking furnace, which is used to heat the combustion chamber and is electrically connected to a controller. The cracking furnace provides a high-temperature environment, ensuring that the combustion chamber reaches a sufficient temperature to promote complete combustion of the coal tar. The controller adjusts the power output of the cracking furnace to precisely control the temperature within the combustion chamber. The controller is electrically connected to the cracking furnace, allowing the operator to set and maintain a specific temperature range. This helps ensure consistent experimental conditions throughout the experiment and reduces errors caused by temperature fluctuations.

[0017] Furthermore, the oxygen inlet pipe and the nitrogen inlet pipe are both provided with flow meters, and the flow meters are electrically connected to the controller. The flow meters are used to monitor the flow rates of oxygen and nitrogen entering the system in real time. The flow meters are electrically connected to the controller, and the controller adjusts the working state of the corresponding valves or pumps according to the set flow parameters to maintain the required gas flow rate. This process is usually implemented through a closed-loop control system to ensure that the flow rate is stable near the preset value. The controller can automatically adjust the flow rate of oxygen and nitrogen according to experimental requirements. For example, under different samples or experimental conditions, it may be necessary to adjust the oxygen supply to optimize combustion efficiency, or adjust the nitrogen flow rate to promote vaporization and form a protective atmosphere.

[0018] Furthermore, it also includes a stirring mechanism, which includes a stirrer, a magnet and a motor. The stirrer is located in the titration tank and is made of ferromagnetic material. The magnet is located at the bottom of the titration tank. The motor is used to drive the magnet to rotate, and the magnet cooperates with the stirrer.

[0019] A stir bar is a small ferromagnetic object (such as an iron or steel rod or ball) located within the titration cell. It is capable of rotating in response to an external magnetic field. A magnet is placed below the bottom of the titration cell, corresponding to the stir bar. The magnet has a strong magnetic field and can act on the stir bar through the glass wall. A motor is connected to the magnet. When the motor rotates, it drives the magnet, which in turn, through magnetic coupling, synchronizes the rotation of the stir bar within the titration cell. As the stir bar rotates within the titration cell, it generates shear forces and eddy currents in the solution, promoting even distribution of substances within the solution and ensuring a more complete and smooth chemical reaction.

[0020] Since there is no physical contact between the magnet and the stirring bar, this design avoids mechanical sealing problems and reduces the risk of leakage, making it particularly suitable for handling corrosive or hazardous liquids.

[0021] Furthermore, the partition plate includes a connecting column and a filter box. The filter box is provided with a nozzle and a filter plate. The filter plate is located in the vaporization chamber, and the nozzle is located in the combustion chamber. The partition plate divides the cracking tube into two independent functional areas - the vaporization chamber and the combustion chamber. This physical separation helps to control the conditions in each area separately to optimize their respective functions. The connecting column is used to fix the position of the partition plate, ensure its stability and sealing, and prevent gas leakage or cross-flow. The filter box is installed on the partition plate and contains a nozzle and a filter plate. It serves as an intermediate transition zone between the vaporization chamber and the combustion chamber. The filter box not only plays a role in physical isolation, but also can perform preliminary purification treatment on the gas entering the combustion chamber from the vaporization chamber to remove any solid particles or other impurities that may be present.

[0022] The filter plate is located inside the vaporizer, near the vaporized gas outlet. It captures and prevents any incompletely vaporized droplets or particles from entering the combustion chamber. This helps reduce combustion byproducts and carbon deposits, thereby improving combustion efficiency and the accuracy of analytical results.

[0023] The nozzle is located inside the combustion chamber, near the filter box outlet. The nozzle design allows filtered gas to enter the combustion chamber at a high velocity and in a uniform distribution, promoting thorough mixing and combustion. It also helps disperse the oxygen supply, ensuring good contact between fuel and oxygen, improving combustion efficiency.

[0024] Furthermore, it also includes a cleaning mechanism, which includes a slider, a first spring and a cleaning rod. The slider is slidably connected to the filter box, and the cleaning rod is fixedly connected to the slider. There are multiple cleaning rods, and the multiple cleaning rods cooperate with the filter holes of the filter plate. One end of the first spring is fixedly connected to the filter box, and the other end is fixedly connected to the slider.

[0025] The slider is mounted on the filter box and slides along a specific track or guide. The slider is designed to move along a predetermined path, driving the cleaning rods in a reciprocating motion. Multiple cleaning rods are attached to the slider, with their positions and spacing designed to match the filter holes in the filter plate. As the slider moves, the cleaning rods follow suit, moving through the filter holes to clean the filter.

[0026] The cleaning rods are securely fastened to the slider, ensuring they remain stable and prevent loosening or shifting during movement. The first spring provides restoring force for the slider. Initially, the cleaning rods are inserted into the filter plate, creating a relatively sealed vaporization chamber. As vaporization begins, the gas inside increases, leading to higher pressure. This pressure pushes the slider, forcing the cleaning rods out of the filter plate. The gas then passes through the filter plate and nozzle, entering the combustion chamber to react with oxygen. Once combustion is complete, the cleaning rods return to their original position under the action of the first spring, allowing them to clean the filter plate.

[0027] This mechanism can automatically clean the filter plate after each reaction, thereby increasing the service life of the filter plate.

[0028] Furthermore, it also includes a steel cable and a second spring. The filter box, nozzle, slider and cleaning rod are provided with two at the upper and lower ends of the connecting column. The steel cable connects the two sliders. One end of the first spring is fixedly connected to the filter box at the upper end, and the other end is fixedly connected to the slider at the upper end. One end of the second spring is fixedly connected to the filter box at the lower end, and the other end is fixedly connected to the slider at the lower end. The first spring cooperates with the second spring.

[0029] Before clogging, the first spring is in a compressed state because the steel cable is in a compressed state, the upper slider and the cleaning rod are not inserted into the upper filter plate, and the lower cleaning rod is inserted into the lower filter plate under the action of the second spring.

[0030] When the upper filter plate is clogged, the pressure in the vaporization chamber increases to the set value, and the air pressure pushes the lower slider back, causing the cleaning rod at the lower end to be extracted from the lower filter plate, allowing the gas to pass through the lower filter plate. When the air pressure drops, the upper slider is pushed out by the first spring, allowing the cleaning rod at the upper end to be inserted into the upper filter plate for cleaning.

[0031] If the lower filter plate becomes clogged, the above operation is repeated, allowing the upper filter plate to flow and the lower filter plate to be cleaned. This design, through an ingenious mechanical linkage mechanism (spring + steel cable + air pressure feedback), achieves alternating cleaning of the upper and lower filter plates, resolving the problem of traditional filter plates being easily clogged and difficult to clean. This not only improves the system's stability and automation, but also significantly enhances the detection device's adaptability and reliability under complex operating conditions. This mechanism eliminates manual intervention and achieves filter plate cleaning through the linkage of air pressure and springs.

[0032] This solution also provides a method for detecting sulfur content in coal tar, comprising the following steps: Step S10: Sample pretreatment: heat coal tar to 80-100°C and stir to homogenize, then add petroleum ether to dilute to a viscosity of ≤50 mPa·s; Step S20: Sample injection: Use the sample injector to load 0.5-1.0 mg of the pretreated sample, push it into the vaporization chamber of the pyrolysis tube, and then introduce heated nitrogen at a nitrogen flow rate of 150-180 mL / min; Step S30: Pyrolysis and titration: oxygen is introduced into the combustion chamber at the same time, with the oxygen flow rate controlled at 200-250 mL / min, and the pyrolysis products are introduced into the sulfur electrolysis cell via carrier gas; Step S40: Data processing: Calculate the sulfur content using Faraday's law, and the software automatically corrects the carbon deposit interference coefficient and outputs the final result.

[0033] This method significantly improves the accuracy of sulfur content detection by optimizing sample pretreatment, precisely controlling the injection volume, providing nitrogen protection, and sufficient oxygen supply.

[0034] The design of the entire process takes into account various factors that may affect the results and takes corresponding measures to control them to ensure that the system can operate stably under different operating conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a structural diagram of a device for detecting sulfur content in coal tar. Figure 2 This is a structural diagram of the stirring mechanism of a device for detecting sulfur content in coal tar. Figure 3 This is a structural diagram of the cracking tube of a device for detecting sulfur content in coal tar. Figure 4 This is a structural diagram of a titration cell for detecting sulfur content in coal tar. Figure 5 This is a structural diagram of a partition board for a device for detecting sulfur content in coal tar. Figure 6 This is an enlarged view of the filter box of a device for detecting sulfur content in coal tar.

[0036] The accompanying drawings in the specification include: 1. cracking tube; 2. cracking furnace; 3. cathode; 4. reference electrode; 5. measuring electrode; 6. anode; 7. external bias; 8. amplifier; 9. computer; 10. sample injector; 11. single-chip microcomputer; 12. flow meter; 13. titration cell; 14. electrolyte; 15. stirring bar; 16. magnet; 17. bracket; 18. motor; 19. power supply; 20. combustion chamber; 21. vaporization chamber; 22. nozzle; 23. heating wire; 24. nitrogen inlet pipe; 25. oxygen inlet pipe; 26. cell body; 27. cell cover; 28. steel cable; 29. ​​first spring; 30. slider; 31. filter plate; 32. connecting pipe; 33. cleaning rod; 34. filter box; 35. second spring; 36. fixed pulley; 37. connecting column. DETAILED DESCRIPTION

[0037] Basically as attached Figure 1 、 Figure 2 As shown: The cracking tube 1 is used to heat and vaporize coal tar and is equipped with a nitrogen inlet pipe 24, which is equipped with a heating wire 23. The sampler 10 accurately loads 0.5-1.0 mg of pretreated coal tar sample and advances it into the vaporization chamber 21. The titration cell 13 measures the SO2 concentration generated by combustion, and combines this with a signal amplification unit to improve detection accuracy. The computer 9 collects and analyzes the electrical signal from the titration cell 13 to calculate the sulfur content. A controller adjusts parameters such as the sample volume, gas flow rate, and temperature to ensure consistent experimental conditions. The cracking furnace 2 provides a high-temperature environment, ensuring that the combustion chamber 20 reaches a sufficient temperature to promote complete combustion of the coal tar. The cracking furnace 2 is located within the combustion chamber 20. A flowmeter 12 monitors and adjusts the flow rates of oxygen and nitrogen to maintain stable experimental conditions. The controller is a single-chip microcomputer 11, which controls the power and efficiency of various electrical devices.

[0038] The signal amplification unit includes an amplifier 8 and an external bias voltage 7. The reference electrode 4 in the titration cell 13 provides a constant reference potential and forms an indicator electrode pair with the measuring electrode 5 to generate a voltage signal. This signal is connected in anti-series with the external bias voltage 7 and applied to the input of the amplifier 8. When the two voltages are equal, the input to the amplifier 8 is zero, and the output is also zero. No current flows between the electrolysis electrode pair, and the instrument display shows a smooth baseline. When the sample is injected into the lysis tube 1 via a syringe, the analyte in the sample reacts and is converted into titratable ions. This ion is carried into the titration cell 13 by the carrier gas, consuming the titrant in the electrolyte 14. Changes in the titrant concentration cause the potential of the indicator electrode pair in the titration cell 13 to change. This change in potential is fed to the microcomputer-controlled amplifier 8, amplified, and applied to the electrolysis electrode pair (cathode 3, anode 6). Titrate ions are electrogenerated at the anode 6 to replenish the consumed titrant. This process continues as the titrant ions are consumed until no more titrant-consuming substances enter the instrument and sufficient titrant ions are generated, returning the value of the indicator electrode pair to the given bias voltage and restoring the instrument to equilibrium. During this process of consuming and replenishing titrant ions, the amount of charge generated by the electrogenerated titrant is measured, and the sample content can be calculated by processing the data according to Faraday's law.

[0039] The stirring mechanism includes a magnet 16, a motor 18, a bracket 17, and a stirrer 15. The motor 18 has its own power supply 19. The stirrer 15 is located within the titration cell 13. The surface of the stirrer 15 is covered with polytetrafluoroethylene, which does not react with the electrolyte. The interior of the stirrer 15 is made of a corrosion-resistant copper alloy. The bracket 17 is fixedly connected to the titration cell 13 and is located below the titration cell 13. The motor 18 is located within the bracket 17. The magnet 16 is fixedly connected to the shaft of the motor 18.

[0040] The motor 18 drives the magnetic steel 16 to rotate, and the magnetic stirring bar in the titration cell 13 rotates evenly with the rotation of the magnetic steel 16, thereby stirring the electrolyte 14. The stirring speed should be neither too fast nor too slow, and should be such that a small vortex is generated in the electrolyte 14. The titration cell 13 should be placed directly above the magnetic steel 16 to prevent the stirring bar from colliding with the cell wall.

[0041] As attached Figure 1 、 Figure 3 As shown: The cracking tube 1 includes a vaporization chamber 21 and a combustion chamber 20. A partition plate is provided in the middle of the cracking tube 1 for partitioning. The vaporization chamber 21 is provided with a sample feed pipe and a nitrogen inlet pipe 24. The nitrogen inlet pipe 24 is provided with a heating wire 23.

[0042] After the nitrogen is preheated, it enters vaporizing chamber 21 and mixes with the sample gas phase, then enters combustion chamber 20 through nozzle 22, and burns in combustion chamber 20 with the oxygen supplied by oxygen inlet pipe 25. Because being designed with larger vaporizing chamber 21 has both guaranteed that sample can be vaporized completely, sample can be made to obtain enough dilution again, obtain higher SO2, the conversion rate of HCl by fully mixing combustion with oxygen with faster flow velocity through nozzle 22. Of course, SO2, the conversion rate of HCl is except that being affected by the cracking tube 1 structure, the bias voltage, gain and other factors selected by cracking zone temperature, oxygen, nitrogen partial pressure ratio, pond operating state and instrument operation also can affect the measurement result. The flow of oxygen inlet pipe 25 and nitrogen inlet pipe 24 all is to be controlled by flow meter 12.

[0043] As attached Figure 1 、 Figure 4 As shown: The titration cell 13 consists of a cell cover 27, a cell body 26, and electrodes. The titration cell 13 is the heart of the microcoulometric titration reaction, reacting the analyte produced by sample decomposition with the titrant in the electrolyte 14. To reduce the volume of the reaction chamber of the titration cell 13, the reference electrode 4 and auxiliary electrode are typically mounted on side arms, connected to the reaction chamber via microporous capillaries. The measuring electrode 5 and the generating electrode are mounted on the cell cover 27. The reaction chamber of the titration cell 13 is typically filled with 10 to 12 mL of electrolyte 14, which meets experimental requirements and achieves high sensitivity and a fast response speed. Gas entering from the combustion tube enters the titration cell 13 through the capillary inlet. The unique structure of the inlet tip of the titration cell 13 breaks the incoming gas into small bubbles through stirring. The stirrer 15 ensures rapid and thorough contact between the reactants and the titrant, forming a uniform diffusion layer.

[0044] As attached Figure 3 、 Figure 5 、 Figure 6 As shown: The partition plate includes a connecting column 37 and a filter box 34. The filter box 34 is equipped with a nozzle 22 and a filter plate 31. The filter plate 31 is located in the vaporization chamber 21, and the nozzle 22 is located in the combustion chamber 20. The partition plate divides the cracking tube 1 into two independent functional areas: the vaporization chamber 21 and the combustion chamber 20. The connecting column 37 is used to fix the position of the partition plate. Filter boxes 34 are installed at the upper and lower ends of the connecting column 37. The filter box 34 is mounted on the partition plate and contains the nozzle 22 and filter plate 31. It serves as an intermediate transition zone between the vaporization chamber 21 and the combustion chamber 20.

[0045] Filter plate 31 is located inside vaporization chamber 21, near the vaporized gas outlet. Filter plate 31 is used to capture and prevent any incompletely vaporized droplets or tiny particles from entering combustion chamber 20. This helps reduce byproducts and carbon deposits produced during the combustion process, thereby improving combustion efficiency and the accuracy of analytical results.

[0046] Nozzle 22 is located inside combustion chamber 20, near the outlet of filter box 34. The design of nozzle 22 allows filtered gas to enter combustion chamber 20 at a high velocity and in a uniformly distributed manner, promoting thorough mixing and combustion. Furthermore, nozzle 22 helps disperse the oxygen supply, ensuring good contact between fuel and oxygen, thereby improving combustion efficiency.

[0047] The cleaning mechanism includes a slider 30, a first spring 29, a second spring 35, and a cleaning rod 33. A filter box 34, a nozzle 22, a slider 30, and a cleaning rod 33 are each located at the top and bottom ends. A connecting pipe 32 is located within a connecting column 37. One end of the connecting pipe 32 connects to the filter box 34 at the top and the other end connects to the filter box 34 at the bottom. The steel cable 28 is fixedly connected to the sliders 30 at the top and bottom through the connecting pipe 32. Fixed pulleys 36 are located at the connecting pipes 32, and the steel cable 28 slides on these fixed pulleys. The slider 30 and the filter box 34 are slidably connected via guide rails. Multiple cleaning rods 33 are provided and fixed to the slider 30. The size of the cleaning rods 33 is slightly smaller than the filter holes in the filter plates 31. The cleaning rods 33 correspond one-to-one with the filter holes in the filter plates 31. One end of the first spring 29 is fixedly connected to the upper filter box 34 and the other end is fixedly connected to the upper slider 30. One end of the second spring 35 is fixedly connected to the lower filter box 34 and the other end is fixedly connected to the lower slider 30.

[0048] Before clogging, the first spring 29 is in a compressed state because the steel cable 28 is in a compressed state, and the upper slider 30 and the cleaning rod 33 are not inserted into the upper filter plate 31 , while the lower cleaning rod 33 is inserted into the lower filter plate 31 under the action of the second spring 35 .

[0049] As attached Figure 1-6 As shown: In operation, coal tar is introduced into the vaporization chamber 21 of the cracking tube 1 via the injector 10. Heated nitrogen within the vaporization chamber 21 heats the coal tar, rapidly vaporizing it at high temperatures. The gas is then filtered through the filter plate 31 of the filter box 34 before being ejected through the nozzle 22. Oxygen is then introduced into the combustion chamber 20 via the oxygen inlet pipe 25. The combustion chamber 20 is heated by the cracking furnace 2, providing sufficient oxidant to completely combust the gaseous coal tar ejected from the nozzle 22. During this process, the sulfur in the coal tar is converted into sulfur dioxide (SO2).

[0050] The SO2-containing gas generated by combustion then enters the titration cell 13. When the system is in equilibrium, the titration cell 13 maintains a constant I3- Concentration, when SO2 enters the titration cell 13, it will react with I3 - Ions react: I3 - +SO2+H2O → SO3+2H + +3I - Resulting in I3 in the pool - The concentration decreases, and the reference and measuring electrodes 5 indicate this change, and input the signal of this change into the amplifier 8, which then outputs a corresponding current to the electrolysis electrode pair. The electrolysis anode 6 generates I3 which is consumed by SO2. - , until the original I3 is restored - Ion concentration: 3I - → I3-+2e By measuring the amount of electricity consumed during electrolysis, the total sulfur content in the sample can be calculated according to Faraday's law of electrolysis. During the titration process, the stirring bar 15 rotates in the titration cell 13, generating shear force and eddy current effects on the solution, promoting uniform distribution of substances in the solution and ensuring a more complete and stable chemical reaction.

[0051] The sensor in the titration cell 13 transmits the detected electrical signals to the computer 9 for analysis. The computer 9 collects and analyzes the electrical signals from the titration cell 13, calculates the SO2 concentration, and further infers the sulfur content in the original sample. The controller regulates the operation of the sampler 10 to ensure the accuracy and repeatability of each injection.

[0052] When the upper filter plate 31 is clogged and the pressure in the vaporization chamber 21 increases to a set value, the air pressure pushes the lower slider 30 back, causing the cleaning rod 33 at the lower end to be drawn out from the lower filter plate 31, allowing gas to pass through the lower filter plate 31. When the air pressure drops, the upper slider 30 is pushed out by the first spring 29, allowing the cleaning rod 33 at the upper end to be inserted into the upper filter plate 31 for cleaning.

[0053] When the filter plate 31 at the lower end is clogged, the above operation is repeated to make the filter plate 31 at the upper end conductive and the filter plate 31 at the lower end clean.

[0054] The beneficial effects of this solution are as follows: 1. The partition design prevents incompletely vaporized liquid or impurities from directly entering the combustion chamber 20, potentially causing adhesion to the inner walls of the combustion chamber 20, preventing the combustion chamber 20 from reaching the set temperature and resulting in incomplete sulfide conversion. 2. Through heating by the heating wire 23 and precise control of the oxygen supply, combustion conditions can be optimized, reducing the formation of incomplete combustion products, thereby reducing analytical errors. 3. The nozzle 22 design effectively increases the flow rate of gas entering the combustion chamber 20, ensuring thorough mixing of the gas and oxygen, thereby improving the sulfur dioxide conversion rate. 4. The amplification unit not only amplifies the useful signal but can also be designed to provide noise suppression, reducing the impact of background noise on the measurement results and further improving the signal-to-noise ratio (SNR). 5. This design, through an ingenious mechanical linkage mechanism (spring + steel cable 28 + air pressure feedback), enables alternating cleaning of the upper and lower filter plates 31, resolving the problem of easy clogging and difficulty in cleaning of conventional filter plates 31. This not only improves the stability and automation level of the system, but also significantly enhances the adaptability and reliability of the detection device under complex operating conditions. This mechanism does not rely on manual intervention, and the filter plate 31 can be cleaned by air pressure and spring linkage.

[0055] This solution also provides a method for detecting sulfur content in coal tar, comprising the following steps: Step S10: Sample pretreatment: heating the coal tar to 80-100°C and stirring for homogenization, and adding petroleum ether to dilute it to a viscosity of ≤50 mPa•s; Step S20: Injection: Use the injector 10 to load 0.5-1.0 mg of the pretreated sample, push it into the vaporization chamber 21 of the pyrolysis tube 1, and then introduce heated nitrogen at a nitrogen flow rate of 150-180 mL / min; Step S30: Pyrolysis and titration: oxygen is introduced into the combustion chamber 20 at the same time, with the oxygen flow rate controlled at 200-250 mL / min, and the pyrolysis products are introduced into the sulfur electrolysis cell via a carrier gas; Step S40: Data processing: Calculate the sulfur content using Faraday's law, and the software automatically corrects the carbon deposit interference coefficient and outputs the final result.

[0056] This method significantly improves the accuracy of sulfur content detection by optimizing sample pretreatment, precisely controlling the injection volume, providing nitrogen protection, and sufficient oxygen supply.

[0057] The design of the entire process takes into account various factors that may affect the results and takes corresponding measures to control them to ensure that the system can operate stably under different operating conditions.

[0058] The above are only embodiments of the present invention. Common knowledge such as the specific structure and characteristics of the scheme is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several variations and improvements can be made, which should also be considered as the scope of protection of the present invention. These will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A device for detecting sulfur content in coal tar, comprising: Cracking tube (1): used for cracking coal tar; Injector (10): used to transport coal tar into the cracking tube (1); Titration cell (13): used to determine the concentration of SO2; Computer (9): used to collect and analyze the electrical signals from the titration cell (13); Controller: The controller is electrically connected to the sample injector (10); It is characterized by: The cracking tube (1) is provided with a partition plate, and the cracking tube (1) is divided into a combustion chamber (20) and a vaporization chamber (21) by the partition plate. The vaporization chamber (21) is connected to the sample injector (10), and the vaporization chamber (21) is provided with an electric heating wire (23). The combustion chamber (20) is connected to the titration cell (13), and the combustion chamber (20) is provided with an oxygen inlet pipe (25) for inputting oxygen. The partition plate is provided with a nozzle (22).

2. The device for detecting sulfur content in coal tar according to claim 1, characterized in that: The vaporization chamber (21) is provided with a nitrogen inlet pipe (24) for inputting nitrogen. The heating wire (23) is arranged on the nitrogen inlet pipe (24). The heating wire (23) is used to heat the nitrogen. The heating wire (23) is electrically connected to the controller.

3. The device for detecting sulfur content in coal tar according to claim 1, characterized in that: It also includes a signal amplification unit, which is electrically connected to the titration cell (13).

4. The device for detecting sulfur content in coal tar according to claim 1, characterized in that: It also includes a cracking furnace (2), the cracking furnace (2) being used to heat the combustion chamber (20), and the cracking furnace (2) being electrically connected to the controller.

5. The device for detecting sulfur content in coal tar according to claim 2, characterized in that: The oxygen inlet pipe (25) and the nitrogen inlet pipe (24) are both provided with a flow meter (12), and the flow meter (12) is electrically connected to the controller.

6. The device for detecting sulfur content in coal tar according to claim 1, characterized in that: The invention also includes a stirring mechanism, wherein the stirring mechanism includes a stirrer (15), a magnetic steel (16) and a motor (18), wherein the stirrer (15) is located in the titration tank (13) and is made of ferromagnetic material, and the magnetic steel (16) is located at the bottom of the titration tank (13). The motor (18) is used to drive the magnetic steel (16) to rotate, and the magnetic steel (16) cooperates with the stirrer (15).

7. The device for detecting sulfur content in coal tar according to claim 1, characterized in that: The partition plate comprises a connecting column (37) and a filter box (34); the filter box (34) is provided with a nozzle (22) and a filter plate (31); the filter plate (31) is located in the vaporization chamber (21); and the nozzle (22) is located in the combustion chamber (20).

8. The device for detecting sulfur content in coal tar according to claim 7, characterized in that: The cleaning mechanism further comprises a slider (30), a first spring (29) and a cleaning rod (33); the slider (30) is slidably connected to the filter box (34); the cleaning rod (33) is fixedly connected to the slider (30); and a plurality of cleaning rods (33) are provided. The plurality of cleaning rods (33) cooperate with the filter holes of the filter plate (31); one end of the first spring (29) is fixedly connected to the filter box (34), and the other end is fixedly connected to the slider (30).

9. The device for detecting sulfur content in coal tar according to claim 8, characterized in that: The invention also includes a steel cable (28) and a second spring (35). The filter box (34), the nozzle (22), the slider (30) and the cleaning rod (33) are provided at two ends of the upper and lower ends of the connecting column (37). The steel cable (28) connects the two sliders (30). One end of the first spring (29) is fixedly connected to the filter box (34) at the upper end, and the other end is fixedly connected to the slider (30) at the upper end. One end of the second spring (35) is fixedly connected to the filter box (34) at the lower end, and the other end is fixedly connected to the slider (30) at the lower end. The first spring (29) and the second spring (35) cooperate with each other.

10. A method for detecting sulfur content in coal tar, characterized in that: The following steps are involved: Step S10: Sample pretreatment: heat coal tar to 80-100°C and stir to homogenize, then add petroleum ether to dilute to a viscosity of ≤50 mPa•s; Step S20: Injection: Use the injector (10) to load 0.5-1.0 mg of the pretreated sample, push it into the vaporization chamber (21) of the pyrolysis tube (1), and then introduce heated nitrogen gas at a nitrogen flow rate of 150-180 mL / min; Step S30: Cracking and titration: oxygen is introduced into the combustion chamber (20) at the same time, the oxygen flow rate is controlled to be 200-250 mL / min, and the cracking products are introduced into the sulfur electrolysis cell via carrier gas; Step S40: Data processing: Calculate the sulfur content using Faraday's law, and the software automatically corrects the carbon deposit interference coefficient and outputs the final result.

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