Integrated carbon residue, ash, volatile matter determination system and determination method

Abstract

The application discloses a kind of integrated residual carbon, ash, volatile determination system and determination method, the system includes: sample introduction device, for carrying and replacing multiple sample crucibles;Weighing device, for automatically weighing sample crucible and its contents;Temperature control device, for providing and controlling the heating environment and atmosphere required for sample crucible to determine residual carbon, ash or volatile matter;System control computing device, for controlling the coordinated operation of sample introduction device, weighing device and temperature control device, and automatically calculating residual carbon, ash or volatile matter value according to the weighing result.The application realizes the high integration of residual carbon, ash, volatile automatic determination function, solves the problem that traditional determination method cannot batch detect, manual operation repeatability is poor, repeated constant weight and cooling process consumes a lot of operator's energy, unifies the detection platform, simplifies equipment configuration and operation process, saves space and instrument procurement cost for laboratory, and facilitates multi-index joint analysis.

Description

Technical Field

[0001] This invention belongs to the field of petrochemical testing, specifically relating to an integrated system and method for determining residual carbon, ash, and volatile matter. Background Technology

[0002] In the field of petrochemical testing, residual carbon, ash content, and volatile matter are important testing indicators.

[0003] Carbon residue is an indicator of the tendency of oil products to form coke under high-temperature conditions in the absence of air. Its value is expressed as a percentage of the original oil product's mass of coke. Carbon residue mainly originates from gums, asphaltenes, condensation products of polycyclic aromatic hydrocarbons, and ash in the oil product. Currently, standard methods for determining carbon residue include the micro-method (GB / T 17144) and the Conrad method (GB / T 268). These methods involve heating the sample to approximately 500℃ to induce the evaporation, decomposition, and eventual condensation of hydrocarbons in the oil product to form coke.

[0004] Ash content is primarily used to assess oil quality, monitor processing, and detect contaminants or adulterants. Ash refers to the inorganic substances remaining after oil combustion, mainly including metal oxides and mineral impurities. Its content reflects the total amount of inorganic impurities in the oil and is usually expressed as a mass percentage. Currently, the standard method for ash content determination is GB / T 508. Its basic principle is to heat the sample until it carbonizes, then ignite it at 775℃ to decompose or oxidize the metal salts it contains into metal oxides (i.e., ash residue). After cooling, the mass of the residue is weighed, and the final result is expressed as a mass fraction.

[0005] Volatile matter is a commonly used key quality indicator in petroleum coke testing, used to measure the content of volatile substances in petroleum coke. Its value typically ranges from 3% to 18%, influenced by factors such as coking temperature and production process. Petroleum coke volatile matter refers to the mass percentage of volatile substances (including moisture, light hydrocarbons, etc.) in petroleum coke under specific conditions (850℃±10℃ anaerobic heating for 7 minutes). The determination of this indicator is based on the standard SH / T 0026.

[0006] The current method for detecting carbon residue, the Concordia method (GB / T 268), is performed manually. Its basic steps are: weigh 3g–10g of sample, preheat for approximately 10 minutes until smoke appears, ignite the smoke and burn for approximately 13 minutes, then further heat the residue for approximately 7 minutes, subsequently cool in a desiccator, weigh, and calculate the result. The Concordia method requires precise control of preheating, combustion, and intense heating times. Manual operation is difficult, has poor repeatability, and sample overflow can easily lead to detection failure. Only one sample can be tested at a time, resulting in low efficiency and being time-consuming and labor-intensive. Furthermore, the crucible must be weighed to constant weight before the experiment. The basic steps of the current micro-method (GB / T17144) for residual carbon detection are as follows: Weigh 0.15g to 5.00g of sample into a sample tube, purge with nitrogen at 600 mL / min for at least 10 minutes in a coking oven, then reduce the nitrogen flow rate to 150 mL / min and heat to 500℃ at a rate of 10℃ / min to 15℃ / min, holding at that temperature for 15 minutes. After stopping heating, purge again with nitrogen at 600 mL / min to cool. Once the temperature is below 250℃, remove the sample, place it in a desiccator to cool, weigh it, and calculate the results. The heating and carbonization process of this method is automatically controlled by the instrument, avoiding the uncertainties of manual operation, and multiple samples (up to 12) can be tested simultaneously. The sample tube does not need to be weighed constantly, but it must be kept clean and not reused. However, this method still has the following limitations: the weighing process requires manual intervention; when the residual carbon content is higher than 5% (mass fraction) and the sample size is small (e.g., 0.15 g), a weighing drift of only 0.2 mg may lead to a deviation of about 0.13% (mass fraction) in the test results; due to the limited volume of the coking oven, the maximum number of tests per test is only 12.

[0007] The standard method for ash content determination (GB / T 508) is summarized as follows: To limit the ash content to 20 mg, weigh no more than 100 g of sample into a pre-weighed crucible and ignite it. If the sample is difficult to ignite directly, an electric furnace can be used for auxiliary heating. For water-containing or viscous heavy oils (such as waxy oils), the heating power must be carefully adjusted, and the temperature should be increased slowly to prevent sample splashing or overflow. After combustion, the crucible is transferred to a muffle furnace at 775℃±25℃ for ashing. After ashing, the crucible is cooled, weighed, and then calcined again until a constant weight is achieved. This method also requires manual operation, and the combustion process is difficult to control. Samples are prone to overflow and splashing due to rapid combustion. Furthermore, airflow disturbances or deflagration of residual char during the transfer of the crucible to the muffle furnace may lead to sample loss. In addition, this method cannot achieve batch processing; only one or a few samples can be processed at a time, making it time-consuming and labor-intensive.

[0008] The volatile matter determination method is applicable to the quality analysis of petroleum coke. The standard method (SH / T 0026) is summarized as follows: The sample, placed in a pre-weighed crucible, is heated in a high-temperature furnace at 850℃±10℃ for 7 minutes without air introduction. It is then removed, cooled, and weighed. The volatile matter content is calculated as the difference between the total mass lost during heating and the mass lost through water evaporation in the sample. This method has the following limitations: the crucible must be pre-weighed, and the furnace temperature must be raised to 850℃±10℃ within 3 minutes after the sample is placed in it; although several samples can be tested simultaneously, the volume of the muffle furnace limits the processing to typically only 6-8 samples, and the pre- and post-weighing procedures are complex, resulting in low overall efficiency.

[0009] In summary, the common problems faced by the above-mentioned detection methods are as follows: first, the detection throughput is low, making batch testing impossible; second, there are many manual operation steps, resulting in poor repeatability; and third, the constant weight and cooling processes before and after testing are cumbersome and time-consuming. To reduce manpower and improve the reliability and reproducibility of results, this invention proposes an integrated system and method for determining residual carbon, ash, and volatile matter, aiming to systematically solve the common problems existing in current detection methods. Summary of the Invention

[0010] This invention provides an integrated system and method for determining residual carbon, ash, and volatile matter. It achieves a high degree of integration of automatic determination functions for three important petrochemical indicators: residual carbon, ash, and volatile matter. It solves the problems of traditional methods for determining residual carbon, ash, and volatile matter, such as the inability to perform batch testing, poor repeatability of manual operation, and the need for repeated constant weighting and cooling processes that consume a lot of operator energy.

[0011] The technical solution adopted by this invention to solve the above-mentioned technical problems is: an integrated system for determining residual char, ash, and volatile matter, comprising: The sample introduction device is used to carry and replace multiple sample crucibles; A weighing device for automatically weighing the sample crucible and its contents; A temperature control device is used to provide and control the heating environment and atmosphere required for the determination of residual carbon, ash, or volatile matter in the sample crucible; The system control computing device is used to control the coordinated operation of the sample injection device, weighing device and temperature control device, and automatically calculate the residual carbon, ash or volatile matter values ​​based on the weighing results.

[0012] Preferably, the sample introduction device includes a sample introduction turntable, a sample introduction support, a stepper motor, and a sample changing U-shaped frame. The sample introduction turntable is a horizontally arranged refractory material tray with multiple circular holes for placing sample crucibles. The sample introduction support is an upright refractory material rod with a connecting plate at its top for rotatably supporting the sample introduction turntable. The output end of the stepper motor is connected to the sample introduction support via a belt. The sample changing U-shaped frame is located outside the temperature control device and is used to move the sample introduction turntable, carrying the sample crucibles, into or out of the temperature control device during volatile matter determination. This sample introduction device can carry multiple sample crucibles at once, enabling batch testing of samples and greatly improving testing efficiency. The stepper motor drives the sample introduction turntable to rotate, achieving automatic and precise sample switching. The design of the U-shaped sample change rack ensures that, in scenarios requiring high-temperature and rapid sample injection, such as volatile matter determination, the sample turntable with multiple sample crucibles can be safely and quickly moved into and out of the high-temperature furnace as a whole, meeting the stringent requirements of standard methods for heating rate.

[0013] Preferably, the sample inlet turntable is provided with an upright pull ring, and the sample change U-shaped frame is provided with a groove that mates with the upright pull ring. By engaging the upright pull ring with the groove, the sample change U-shaped frame can mechanically grip and lock the sample inlet turntable, resulting in a simple and reliable structure.

[0014] Preferably, the weighing device includes a push rod, a weighing balance, and a shifting motor. The push rod is a T-shaped refractory rod with a disc at its top for lifting the sample crucible from below. The weighing balance is connected to the push rod and is equipped with a lifting mechanism. The shifting motor drives the push rod to move horizontally below the sample crucible to be weighed, and then the lifting mechanism lifts the push rod, causing the sample crucible to be weighed to detach from the sample turntable for weighing. This weighing device enables automatic weighing of individual sample crucibles in high-temperature environments, eliminating the need for manual removal and cooling of the sample crucibles before weighing, thus saving time and manpower by eliminating repeated cooling and transfer steps. Combined with the rotation of the sample turntable, all sample crucibles can be weighed sequentially, achieving automation and batch weighing of the weighing process.

[0015] Preferably, a hollow refractory limiting cylinder is fitted around the outer side of the push rod. The limiting cylinder is fixed inside the temperature control device. A positioning ring and a dust cover are provided on the push rod. The outer diameter of the positioning ring is larger than the inner diameter of the limiting cylinder. The dust cover is positioned above the positioning ring. A cross-shaped horizontal tail support is fixed to the bottom of the push rod. The design of the limiting cylinder ensures the centering accuracy and stability of the push rod during vertical movement, preventing frictional resistance caused by the push rod contacting the limiting cylinder wall and affecting weighing accuracy. The dust cover effectively prevents dust and particulate matter from falling onto the weighing balance, ensuring weighing accuracy and instrument reliability over long-term use. The horizontal tail support ensures the push rod's upright stability when not in operation.

[0016] Preferably, the sample crucible has an inverted convex shape with a circular cross-section. The upper half of the sample crucible is fitted into the circular hole of the sample inlet turntable. The diameter of the sample crucible base is smaller than the diameter of the disc, and the diameter of the disc is smaller than the diameter of the circular hole. The upper half of the sample crucible being fitted onto the sample inlet turntable ensures stable support and precise positioning of the sample crucible, preventing it from tipping over or shifting during rotation or movement. The smaller diameter of the sample crucible base compared to the disc, and the smaller diameter of the disc compared to the diameter of the circular hole, ensures that the push rod can smoothly pass through the circular hole, accurately lifting the crucible base for weighing without interfering with the sample inlet turntable.

[0017] Preferably, the temperature control device includes a heating coil, a furnace chamber, an outer cavity, a temperature probe, an air inlet, and an exhaust port. The furnace chamber is a sealed heating cavity made of refractory material, comprising an openable upper and lower section. The heating coil is located in the upper section of the furnace chamber, and the outer cavity is fitted over the furnace chamber. Insulating material is filled between the furnace chamber and the outer cavity. The temperature probe, air inlet, and exhaust port are located in the lower section of the furnace chamber. The air inlet is used to introduce nitrogen or air, and the exhaust port is connected to an external ventilation device. The furnace chamber adopts a split design consisting of an upper and lower section, which facilitates the placement and removal of sample crucibles, provides a uniform and controllable high-temperature environment during operation, reduces heat loss, and improves energy efficiency and temperature uniformity. The design of the temperature probe, air inlet, and exhaust port allows the system to flexibly create an inert atmosphere (for residual carbon and volatile matter) or an oxidizing atmosphere (for ash) within the furnace, meeting the essential requirements of three different detection methods and ensuring the realization of multiple functions of the integrated system.

[0018] Preferably, the system control computing device is pre-programmed with carbon residue determination, ash content determination, and volatile matter determination programs. The carbon residue determination program includes: first, purging with nitrogen, then heating at a set rate to approximately 500°C and holding at that temperature, and finally cooling with nitrogen. The ash content determination program includes: slowly heating the sample in an inert atmosphere to char it, then switching to an air atmosphere for high-temperature ashing. The volatile matter determination program includes: rapidly heating the sample to approximately 850°C under anaerobic conditions and holding for a set time, then rapidly cooling it. By pre-programming carbon residue determination, ash content determination, and volatile matter determination programs that conform to national standards in the system control computing device, the complex, experience-dependent operational procedures (such as heating rate, holding time, and atmosphere switching timing) of traditional methods are transformed into standardized, automatically executable procedures. This greatly reduces the operational difficulty and technical threshold, eliminates random errors and inconsistencies in time control caused by human operation, and significantly improves the repeatability and accuracy of the test results. In addition, the setting of charring followed by ashing in the ash content determination program effectively simulates the standard method and avoids the risks of splashing and deflagration when the sample is directly burned.

[0019] A determination method using the aforementioned integrated system for determining residual carbon, ash, and volatile matter includes the following steps: (1) Place multiple sample crucibles on the sample introduction device; (2) Control the temperature control device to perform high-temperature constant weight treatment on the sample crucible; (3) The mass of the crucible after constant weight is automatically weighed by the weighing device, and the sample is added to it and the sample mass is weighed. (4) Control the temperature control device to execute the corresponding heating program according to the selected measurement items; (5) After the program is completed, the mass of the sample crucible is automatically weighed again by the weighing device; (6) Based on the weighing results of steps (3) and (5), automatically calculate and output the content of residual carbon, ash or volatile matter.

[0020] The present invention integrates the traditional methods of dispersion, manual constant weight, weighing, heating, cooling, re-weighing, and calculation into a continuous, automatic, and closed process. This effectively solves the problems of poor repeatability of manual operations and the cumbersome and time-consuming constant weight and cooling processes before and after testing in traditional methods. It frees up operators, making the testing work more efficient, easier, and the results more reliable. Preferably, in step (2), the high-temperature constant weight treatment can be performed at 775℃. +After calcination at 25℃, weigh directly, then calcinate again for 10 minutes and weigh again. As long as the two consecutive weighings do not exceed 0.4mg, constant weight can be considered to be completed, saving time. In step (3), when weighing the sample, the sample can be pre-weighed. After the top rod lifts the crucible, when the sample is added to the range required by the corresponding method, the top rod will automatically fall, the turntable will rotate, and the next crucible will be replaced. After the pre-weighing is completed, the device is turned off and the accurate weighing is performed again. In the ash content determination, the re-weighing in step (5) is performed directly after high-temperature ashing constant weight, thereby utilizing the data from the high-temperature constant weight processing in step (2), omitting unnecessary cooling steps, and further saving time. In the residual carbon determination, the re-weighing in step (5) is performed at a set temperature below 500℃, so weighing at 400℃ can be used, thereby avoiding the influence of weighing at 500℃ (process temperature) on the coking reaction. At the same time, it is faster to complete the detection than cooling to room temperature, optimizing the detection speed while ensuring the accuracy of the results. In the volatile matter determination, the re-weighing in step (5) is performed at a set temperature below 500℃, so weighing at 400℃ can be used, thereby avoiding the influence of weighing at 500℃ (process temperature) on the coking reaction. It is also faster to complete the detection than cooling to room temperature, thus optimizing the detection speed while ensuring the accuracy of the results. In the determination of volatile matter, before step (4), the sample transfer U-shaped frame is used to move the sample-carrying turntable into the temperature control device that has been preheated to about 850°C, thereby realizing the rapid overall transfer of the sample, which meets the stringent requirement of "the furnace temperature should rise to 850°C±10°C within 3 minutes" in the national standard for petroleum coke volatile matter (SH / T0026), ensuring the standardization and accuracy of the test; in order to ensure the validity of the results, 1-3 crucibles can be set as blanks, and the average mass difference before and after the test can be used as the blank for deduction, in order to correct the influence of temperature change on crucible mass and weighing.

[0021] Compared with the prior art, the present invention has the following advantages: The integrated carbon residue, ash content and volatile matter determination system and method of the present invention achieves a high degree of integration of automatic determination functions of three important petrochemical indicators, carbon residue, ash content and volatile matter. It solves the problems of traditional carbon residue, ash content and volatile matter determination methods being unable to perform batch testing, poor repeatability of manual operation, and the large amount of energy consumed by operators in the repeated constant weight and cooling process. It unifies the detection platform, simplifies equipment configuration and operation process, saves space and instrument procurement costs for the laboratory, and facilitates multi-indicator joint analysis. Attached Figure Description

[0022] Figure 1 This is a perspective view of the measurement system in Example 1; Figure 2 This is a top view of the sample introduction turntable in Example 1; Figure 3 This is a schematic diagram showing the connection between the sample inlet support and the stepper motor in Example 1; Figure 4 This is a schematic diagram showing the effect of assembling the push rod and the limiting cylinder in Example 1; Figure 5 This is a front view of the sample crucible in Example 1; Figures 1-5 The specific reference numerals in the attached figures are as follows: 11-Sample inlet turntable, 12-Sample inlet bracket, 13-Stepper motor, 131-Belt, 14-Sample changing U-shaped frame, 141-Groove, 15-Round hole, 16-Triangular hole, 17-Upright pull ring, 18-Connecting plate, 19-Triangular protrusion, 21-Top rod, 22-Weighing balance, 23-Disc, 24-Limiting cylinder, 25-Positioning ring, 26-Dust cover, 27-Horizontal tail support, 31-Heating coil, 321-Upper part, 322-Lower part, 33-External cavity, 34-Temperature probe, 35-Air inlet, 36-Exhaust port, 41-Sample crucible. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0024] Example 1: Integrated system for determining residual char, ash, and volatile matter, such as Figures 1-4 As shown, it includes: a sample injection device for carrying and replacing multiple sample crucibles 41; a weighing device for automatically weighing the sample crucibles 41 and their contents; a temperature control device for providing and controlling the heating environment and atmosphere required for the determination of residual carbon, ash, or volatile matter in the sample crucibles 41; and a system control calculation device (not shown in the figure) for controlling the coordinated operation of the sample injection device, the weighing device, and the temperature control device, and automatically calculating the residual carbon, ash, or volatile matter values ​​based on the weighing results.

[0025] In Example 1, the sample introduction device includes a sample introduction turntable 11, a sample introduction support 12, a stepper motor 13, and a sample changing U-shaped frame 14. The sample introduction turntable 11 is a horizontally arranged refractory material tray with multiple circular holes 15 for placing sample crucibles 41. A triangular hole 16 is provided in the center of the sample introduction turntable 11. An upright pull ring 17 is provided on the sample introduction turntable 11. The sample introduction support 12 is an upright refractory material rod with a top for rotatably supporting the sample introduction turntable 11. The connecting plate 18 of the 1 has a triangular protrusion 19 in the middle, which is engaged with the triangular hole 16 in the middle of the sample feeding turntable 11. The output end of the stepper motor 13 is connected to the sample feeding bracket 12 via the belt 131. The sample changing U-shaped frame 14 is set outside the temperature control device. The sample changing U-shaped frame 14 has a groove 141 that cooperates with the upright pull ring 17. The sample changing U-shaped frame 14 is used to move the sample feeding turntable 11 carrying the sample crucible 41 into or out of the temperature control device during the determination of volatile matter.

[0026] In Example 1, the weighing device includes a top rod 21, a weighing balance 22, and a transposition motor (not shown in the figure). The top rod 21 is a T-shaped refractory rod. A disc 23 for lifting the sample crucible 41 from below is located at the top of the top rod 21. The weighing balance 22 is connected to the top rod 21. A hollow refractory limiting cylinder 24 is fitted around the outside of the top rod 21. The limiting cylinder 24 is fixed inside the temperature control device. A positioning ring 25 and a dust cover 26 are provided on the top rod 21. The outer diameter of the 5 is larger than the inner diameter of the limiting cylinder 24. The dust cover 26 is located above the positioning ring 25. A cross-shaped horizontal tail support 27 is fixed to the bottom of the top rod 21. The weighing balance is equipped with a lifting mechanism. The shifting motor is used to drive the top rod 21 horizontally to the bottom of the sample crucible to be weighed via a screw drive. Then, the lifting mechanism lifts the top rod 21, and the sample crucible 41 is lifted by the disc 23, so that the sample crucible 41 to be weighed is removed from the sample feeding turntable 11 for weighing. Figure 5 As shown, the outer part of the sample crucible 41 is an inverted convex structure with a circular cross-section. The upper part of the sample crucible 41 is inserted into the circular hole 15 of the sample feed turntable 11. The diameter of the base of the sample crucible 41 is smaller than the diameter of the disc 23, and the diameter of the disc 23 is smaller than the aperture of the circular hole 15.

[0027] In Example 1, the temperature control device includes a heating coil 31, a furnace chamber, an outer cavity 33, several temperature probes 34, several air inlets 35, and several exhaust ports 36. The furnace chamber is a sealed heating cavity made of refractory material. The furnace chamber includes an openable upper part 321 and a lower part 322. The heating coil 31 is disposed in the upper part 321 of the furnace chamber. The outer cavity 33 is sleeved outside the furnace chamber. The space between the furnace chamber and the outer cavity 33 is filled with heat insulation material. The temperature probes 34, air inlets 35, and exhaust ports 36 are respectively disposed in the lower part 322 of the furnace chamber. The air inlets 35 are used to introduce nitrogen or air. The exhaust ports 36 are connected to an external ventilation device (not shown in the figure).

[0028] In Example 1, the system control computing device is pre-set with a carbon residue determination program (compliant with GB / T17144), an ash content determination program (compliant with GB / T 508), and a volatile matter determination program (compliant with SH / T 0026) based on existing technologies. The carbon residue determination program includes: first, purging with nitrogen, then heating at a set rate to about 500°C and holding at that temperature, and finally cooling with nitrogen. The ash content determination program includes: slowly heating the sample under an inert atmosphere to char it, and then switching to an air atmosphere for high-temperature ashing. The volatile matter determination program includes: rapidly heating the sample under anaerobic conditions to about 850°C and holding it for a set time, and then rapidly cooling it.

[0029] Example 2: The ash content of five heavy oil samples was determined using the determination system of Example 1, including the following steps: 1) Placement and Constant Weight: Place five clean 50mL sample crucibles into the round hole of the sample inlet turntable. Close the furnace and call the ash content determination program. First, in an air atmosphere, heat to 775℃±25℃ and calcine at this temperature for 10 minutes, then weigh. Calcine again at this temperature for 10 minutes, then weigh again. This completes the first constant weight calcination.

[0030] 2) Initial Weighing: The system automatically controls the furnace temperature at 775℃±25℃. After each calcination, the gas is stopped, and the weighing rod, in conjunction with the sample inlet turntable, aligns with each crucible sequentially, lifting it for automatic weighing. The system records the penultimate calcination mass (T0) and the final calcination mass (T1) for each crucible. If the difference between T1 and T0 does not exceed 0.4 mg, constant weight is considered achieved; otherwise, calcination continues until the target is met.

[0031] 3) Sample Addition and Weighing: After the furnace temperature drops to room temperature, open the furnace cover. Rotate the sample inlet turntable to move the first crucible to the sample addition and weighing position (an automatic sampler can be connected or manual sample addition can be performed), adding approximately 20g of oil sample. At this time, perform a pre-weighing: the push rod lifts the crucible to weigh its "gross weight" (T2). The system automatically calculates and records the sample gross weight (T2 - T1). Once the gross weight reaches the required range set by the method, the push rod falls, the sample inlet turntable rotates, and the next crucible is replaced. Repeat this process until all 5 samples have been added. After closing the furnace, stop the gas supply and weigh the crucible again, recording the crucible mass at this time as T3.

[0032] 4) Programmed ashing: After shutting down the furnace, the system executes the ashing program: ① In a nitrogen atmosphere, the temperature is slowly increased to 500℃ at a rate of 15℃ / min to ensure stable charring of the sample and prevent splashing and deflagration; ② Switch to an air atmosphere and increase the temperature to 775℃±25℃ at a rate of 30℃ / min; ③ Calcination is carried out at a constant temperature in an air atmosphere for at least 2 hours to ensure complete ashing.

[0033] 5) High-Temperature Re-weighing and Constant Weight Measurement: After the program ends, the furnace temperature is maintained at 775℃. Gas is stopped, and the system automatically performs a high-temperature re-weighing (T4). Subsequently, the system is calcined at a constant temperature for 15 minutes and a second high-temperature weighing is performed (T5). If the difference between the two consecutive weighings does not exceed 0.4mg, constant weight measurement is considered complete; otherwise, calcination continues until the target is met.

[0034] 6) Calculation and Output of Results: The system automatically calculates the ash content according to the formula: Ash (%) = [(T5 - T1) / (T3 - T1)] × 100%. The results are automatically displayed and stored.

[0035] Example 3: The carbon residue of eight lubricating oil base oil samples was determined using the testing system of Example 1, including the following steps: 1) Crucible high-temperature constant weight treatment: Place 8 crucibles and call the residual carbon determination program. The system first performs high-temperature constant weight treatment on the crucibles at 775℃ in air atmosphere (method is the same as ash constant weight treatment) until the mass is constant, and records it as the reference mass (W1).

[0036] 2) Sample addition and weighing: After cooling to room temperature, add about 10g of oil sample to each crucible in sequence, and weigh the sample immediately after adding it with the furnace and gas turned off. Record the weight as (W2) and calculate the sample mass (m = W2 - W1).

[0037] 3) Programmed coking: Shut down the furnace and strictly follow the standard procedure: ① Purge with nitrogen at 600 mL / min for 10 minutes; ② Reduce the nitrogen flow rate to 150 mL / min and heat to 500℃ at a rate of 12℃ / min; ③ Maintain a constant temperature of 500℃ for 15 minutes; ④ Stop heating and switch to rapid cooling with nitrogen at 600 mL / min.

[0038] 4) Low-temperature re-weighing: When the furnace temperature drops to 400℃, the system automatically stabilizes the temperature, stops the gas supply, and re-weighs all crucibles in sequence, recording the result as (W3).

[0039] 5) Calculation and output of results: The system automatically calculates the residual carbon value according to the formula: Residual carbon (%) = [(W3 - W1) / m] × 100%.

[0040] Example 4: The volatile matter of six petroleum coke samples was determined using the determination system of Example 1, including the following steps: 1) Crucible preparation: Place 6 covered sample crucibles, call the volatile matter determination program in the system, and complete the high temperature constant weight treatment (M1) in the furnace according to the standard program, the method is the same as the ash constant weight treatment.

[0041] 2) Sample addition: After the furnace has cooled to room temperature, add approximately 5g of petroleum coke sample to each crucible in sequence. After adding the sample, weigh it (M2) under the condition that the furnace is closed and the gas supply is stopped at room temperature, and calculate the sample mass. Then open the upper part of the furnace, align the groove on the sample changing U-shaped frame with and insert it into the upright pull ring of the sample inlet turntable, remove the entire sample inlet turntable carrying 6 samples, and place it in a standby position.

[0042] 3) High-Temperature Rapid Sample Injection: The system's temperature control device rapidly heats the sample to 850℃±10℃ in a nitrogen atmosphere under no-load conditions and stabilizes. At this point, the upper part of the furnace is opened. The groove on the sample transfer U-shaped frame is aligned and engaged with the upright pull ring of the sample injection turntable. The entire sample injection turntable, carrying six samples, is then quickly moved into the center of the furnace. The total time from opening the upper part of the furnace to sample placement is controlled within 3 minutes, meeting the standard requirements.

[0043] 4) Programmed calcination: Immediately shut down the furnace, start the system timing, and calcine at a constant temperature of 850℃ for 7 minutes under oxygen-free (nitrogen) conditions.

[0044] 5) Rapid Cooling and Weighing: After 7 minutes, the system immediately stops heating and introduces a high flow rate of nitrogen for forced rapid cooling. Once the furnace temperature drops below 300°C, the nitrogen flow rate is reduced. After continuing to cool to room temperature (approximately below 50°C) and stopping the nitrogen flow, the system automatically reweighs all crucibles (M3).

[0045] 6) Result Calculation and Output: The system automatically calculates the volatile matter content: Volatile matter (%) = {[(M2 - M3) - Moisture mass] / (M2 - M1)} × 100%. (Moisture mass can be determined by taking another sample or subtracted based on experience).

Claims

1. An integrated system for determining residual char, ash, and volatile matter, characterized in that, include: The sample introduction device is used to carry and replace multiple sample crucibles; A weighing device for automatically weighing the sample crucible and its contents; A temperature control device is used to provide and control the heating environment and atmosphere required for the determination of residual carbon, ash, or volatile matter in the sample crucible; The system control computing device is used to control the coordinated operation of the sample injection device, weighing device and temperature control device, and automatically calculate the residual carbon, ash or volatile matter values ​​based on the weighing results.

2. The integrated carbon residue, ash, and volatile matter determination system according to claim 1, characterized in that, The sample introduction device includes a sample introduction turntable, a sample introduction support, a stepper motor, and a sample changing U-shaped frame. The sample introduction turntable is a horizontally arranged refractory material tray with multiple circular holes for placing sample crucibles. The sample introduction support is an upright refractory material rod with a connecting plate at the top for rotatably supporting the sample introduction turntable. The output end of the stepper motor is connected to the sample introduction support via a belt. The sample changing U-shaped frame is located outside the temperature control device and is used to move the sample introduction turntable, which carries the sample crucibles, into or out of the temperature control device during volatile matter determination.

3. The integrated carbon residue, ash, and volatile matter determination system according to claim 2, characterized in that, The sample feed turntable is equipped with an upright pull ring, and the sample changing U-shaped frame is equipped with a groove that mates with the upright pull ring.

4. The integrated system for determining residual char, ash, and volatile matter according to claim 2, characterized in that, The weighing device includes a push rod, a weighing balance, and a shifting motor. The push rod is a T-shaped refractory rod with a disc at its top for lifting the sample crucible from below. The weighing balance is connected to the push rod and is equipped with a lifting mechanism. The shifting motor drives the push rod to move horizontally to below the sample crucible to be weighed, and then the lifting mechanism lifts the push rod, causing the sample crucible to be weighed to detach from the sample inlet turntable for weighing.

5. The integrated carbon residue, ash, and volatile matter determination system according to claim 4, characterized in that, A hollow fire-resistant limiting cylinder is fitted on the outer side of the top rod. The limiting cylinder is fixed inside the temperature control device. A positioning ring and a dust cover are provided on the top rod. The outer diameter of the positioning ring is larger than the inner diameter of the limiting cylinder. The dust cover is located above the positioning ring. A cross-shaped horizontal tail support is fixed at the bottom of the top rod.

6. The integrated system for determining residual char, ash, and volatile matter according to claim 4 or 5, characterized in that, The sample crucible has an inverted convex shape with a circular cross-section on the outside. The upper part of the sample crucible is fitted into the circular hole of the sample feed turntable. The diameter of the base of the sample crucible is smaller than the diameter of the turntable, and the diameter of the turntable is smaller than the diameter of the circular hole.

7. The integrated carbon residue, ash, and volatile matter determination system according to claim 1, characterized in that, The temperature control device includes a heating coil, a furnace chamber, an outer cavity, a temperature probe, an air inlet, and an exhaust port. The furnace chamber is a sealed heating cavity made of refractory material, and includes an openable upper part and a lower part. The heating coil is located in the upper part of the furnace chamber, and the outer cavity is fitted outside the furnace chamber. The space between the furnace chamber and the outer cavity is filled with heat insulation material. The temperature probe, air inlet, and exhaust port are respectively located in the lower part of the furnace chamber. The air inlet is used to introduce nitrogen or air, and the exhaust port is connected to an external ventilation device.

8. The integrated system for determining residual char, ash, and volatile matter according to claim 1, characterized in that, The system control computing device is preset with a carbon residue determination program, an ash content determination program, and a volatile matter determination program. The carbon residue determination program includes: first, purging with nitrogen gas, then heating at a set rate to approximately 500°C and holding at that temperature, and finally cooling with nitrogen gas. The ash content determination program includes: slowly heating the sample under an inert atmosphere to char it, and then switching to an air atmosphere for high-temperature ashing. The volatile matter determination program includes: rapidly heating the sample under anaerobic conditions to approximately 850°C and holding it for a set time, and then rapidly cooling it.

9. A determination method using the integrated carbon residue, ash, and volatile matter determination system as described in any one of claims 1-8, characterized in that, Includes the following steps: (1) Place multiple sample crucibles on the sample introduction device; (2) Control the temperature control device to perform high-temperature constant weight treatment on the sample crucible; (3) The mass of the crucible after constant weight is automatically weighed by the weighing device, and the sample is added to it and the sample mass is weighed. (4) Control the temperature control device to execute the corresponding heating program according to the selected measurement items; (5) After the program is completed, the mass of the sample crucible is automatically weighed again by the weighing device; (6) Based on the weighing results of steps (3) and (5), automatically calculate and output the content of residual carbon, ash or volatile matter.

10. The determination method according to claim 9, characterized in that, In the ash content determination, the re-weighing in step (5) is performed directly after high-temperature ashing to constant weight; in the residual carbon determination, the re-weighing in step (5) is performed at a set temperature below 500°C; in the volatile matter determination, before step (4), the sample-carrying U-shaped frame is used to move the sample-carrying turntable into the temperature control device that has been preheated to about 850°C.

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