Method of using an oil tank simulation experimental device to enhance the settling and deashing effect of oil slurry

Abstract

This invention belongs to the field of oil slurry sedimentation and deashing technology, and specifically relates to a method for an oil tank simulation experimental device that enhances the deashing effect of oil slurry sedimentation. The oil tank simulation experimental device is characterized by comprising a base, a tubular container body mounted on the base, several sampling tubes extending into the center of the cross-section of the tubular container body, sampling tube valves at the ends of each sampling tube, a top end cap at the top of the tubular container body, a temperature measurement system, and an external wall heating system. This invention is rationally designed, simple, and feasible, simulating the internal environment of an oil tank as closely as possible. It maximizes the height of the oil container to a level comparable to that of a real storage tank, facilitating sampling at different heights to examine the differences in oil composition at different heights in the tank, as needed for experiments. Based on this experimental device, the provided process method can remove ash from oil slurry in a shorter time and at a lower cost, thus improving the quality of subsequent processed products.

Description

Technical Field

[0001] This invention belongs to the field of oil slurry settling and deashing technology, and in particular relates to a method for using an oil tank simulation experimental device to enhance the effect of oil slurry settling and deashing. Background Technology

[0002] In recent years, the utilization of catalytic cracking slurry oil has become a hot topic in the industry, with needle coke and petroleum coke, as well as low-sulfur marine fuel oil, being the most profitable specialty products. The main issue with using slurry oil for marine fuel production is the catalyst powder content, reflected in the aluminum + silicon content index. The revised petroleum coke standard in 2019 has stricter and more detailed regulations on ash content. For each grade increase above 3A, the ash content requirement increases by 500 ppm, and one of the important sources of petroleum coke ash is the catalyst powder in the slurry oil. Therefore, reducing the ash content of slurry oil is essential for its comprehensive utilization. Currently, there are two main methods for reducing ash content in slurry oil: mechanical filtration deashing and settling agent deashing. Mechanical filtration deashing is more effective and stable; however, it requires relatively expensive fixed locations and equipment investment, filter element maintenance, regeneration and replacement, and complex backwashing processes. Settling deashing requires no fixed equipment investment and has a simple process flow; however, settling agents are more expensive, the deashing effect is not as good as mechanical filtration deashing, and it is unstable. In summary, the costs of the two methods are roughly on the same order of magnitude, each with its own advantages and disadvantages.

[0003] The main problem with slurry sedimentation and deashing is that the effect does not meet the process requirements, and the deashing is unstable for different types of slurry. Slurry sedimentation involves two processes: coagulation and flocculation. The former, with the help of coagulants, neutralizes the surface charge of ash solid particles, enabling them to overcome the electrostatic repulsion between solid particles, stably removing particles and forming fine aggregates. The latter involves the formation of flocs from the aggregates under the bridging effect of organic polymeric flocculants; this process also involves charge neutralization. Organic polymeric flocculants adsorb onto the surface of ash solid particles through hydrogen bonds or ion pairs formed by their polar or ionic groups, coupled with van der Waals forces, bridging the ash solid particles and forming flocculent precipitates. However, in recent years, the degree of cracking in the catalytic cracking processes of various refineries has increased compared to previous years, resulting in heavier slurry. This increases the viscosity of the oil slurry system, causing the catalyst powder in the slurry to be coated with high-viscosity heavy oil. This hinders the aforementioned coagulation process, preventing the formation of fine aggregates. Simultaneously, the increased viscosity also impedes the flocculation and sedimentation process, prolonging the settling time. Typically, oil slurry sedimentation experiments conducted in small laboratory vessels show acceptable results, but because the actual height of the oil tank is not considered, the actual settling time is much longer than the laboratory observation time, resulting in low settling efficiency. Investigations have revealed similar problems with products from various flocculant manufacturers.

[0004] Existing oil tank simulation experimental setup:

[0005] (1) Existing scientific research and sampling analysis in oil tanks mostly use conventional laboratory containers for sampling, ignoring the impact of the actual height of the tank on experiments and sampling analysis.

[0006] (2) Existing oil tank simulation experimental devices focus on the closeness of size ratio and the comprehensiveness of supporting facilities, resulting in high manufacturing costs. Moreover, most of them ignore the importance of absolute height and do not provide sampling methods for different heights.

[0007] Existing oil slurry deashing process:

[0008] (1) Existing oil slurry deashing process can use mechanical filtration, but it requires a dedicated filtration site and filtration device, and needs to be equipped with a filtration process and a backwashing process. Furthermore, the treatment of backwash liquid is a major challenge.

[0009] (2) The existing oil slurry deashing process directly uses a settling agent for sedimentation, but the effect is generally poor and there is a big gap compared with mechanical filtration, making it difficult to meet the quality requirements of subsequent processed products. Moreover, the cost of settling agents is high.

[0010] Patent CN209117497U provides an experimental platform for oil storage tanks, primarily for explosion-proof design and safety protection. While this device can simulate the internal environment of an oil tank, its simulated tank dimensions are similar in scale to actual tanks, but its absolute height is insufficient, falling below the meter level. In sedimentation, flocculation, and stratification experiments, experimental devices smaller than meters often differ significantly from reality, mainly because they fail to consider the long-term combined effects of height and gravity on the internal medium. Summary of the Invention

[0011] The purpose of this invention is to provide a method for simulating an oil tank using an enhanced oil slurry settling and deashing device, so that the height of the oil container is as close as possible to that of a real storage tank, facilitating sampling at different heights and allowing for examination of the differences in oil composition at different heights of the tank according to experimental needs.

[0012] The objective of this invention is achieved through the following technical solution:

[0013] The oil tank simulation experimental device for enhancing the settling and deashing effect of oil slurry of the present invention is characterized by comprising a base, a tubular container body disposed on the base, several sampling tubes extending into the center position of the cross-section of the tubular container body, a sampling tube valve disposed at the end of each sampling tube, a top end cap disposed at the top of the tubular container body, a temperature measuring system, and an outer wall heating system.

[0014] The tubular container body is a vertical structure in the shape of a hollow cylinder or a hollow cuboid, with a height of 1 meter or more, a diameter of 1 decimeter or more, and a length-to-diameter ratio greater than 10.

[0015] The tubular container body is made of stainless steel, glass, or transparent resin material through thermoforming.

[0016] The base is a flat rectangular parallelepiped or a flat cylindrical shape, and the base is formed or welded to the tubular container body in one piece.

[0017] The sampling tube is formed or welded to the tubular container body in one piece, and the sampling tube has a hollow structure.

[0018] The temperature measuring system includes a sealed temperature measuring tube extending into the tubular container body, and a thermocouple or glass thermometer inserted into the sealed temperature measuring tube.

[0019] The aforementioned external wall heating system includes heat tracing heating or radiant heating.

[0020] A method for simulating an oil tank using an enhanced oil slurry settling and deashing device, characterized by comprising the following steps:

[0021] (1) Place the device near a continuous heat source, close all sampling tube valves, open the top end cap, and inject clean oil such as diesel, kerosene, petroleum ether, toluene, etc. until the tubular container body is full. After standing for a period of time, open the sampling tube valve at the end of the lowest sampling tube, drain the dirty oil, and then close the sampling tube valve.

[0022] (2) Mix the target type of oil slurry to be deashed with a low-viscosity oil that has little impact on subsequent processing at a ratio of 5 to 50. The viscosity of the mixed oil sample at 50°C should be 100 mmHg. 2 For concentrations below 0.01% to 10% of the mixed oil sample, add a settling agent.

[0023] (3) Inject the mixed oil and settling agent into the tubular container body 1, with the liquid level higher than the uppermost sampling tube; then cover the top end cap, insert the thermocouple or glass thermometer into the sealed temperature measuring tube; raise the temperature of the device or the device environment to 50℃~100℃, maintain it for 12h~120h, and open each sampling tube in sequence to collect oil samples from different locations for analysis of ash content, molecular composition, etc.

[0024] (4) Calculate the ash settling rate based on the difference in ash content of samples at different heights;

[0025] (5) Repeat steps (2) to (4) to conduct experiments with different concentrations of settling agent and determine the ash settling rate at different concentrations;

[0026] (6) Based on the settling rate measured in step (5), the settling time and settling time for industrial production are determined by taking into account factors such as settling time and settling agent cost.

[0027] (7) After the experiment is completed, open the sampling tube at the lowest position, drain the remaining oil sample and then close the sampling tube valve; then open the top end cap and inject clean oil such as diesel, kerosene, petroleum ether, toluene, etc. until the tubular container is full; close the top end cap and wait for the next experiment.

[0028] Advantages of this invention:

[0029] The process method and oil tank simulation experimental device for enhancing the ash removal effect of oil slurry sedimentation of the present invention are reasonably designed, simple and feasible, and simulate the internal environment of the oil tank as much as possible. The height of the oil container is made to be comparable to that of a real storage tank, which facilitates sampling at different heights to examine the differences in oil composition at different height positions of the oil tank according to experimental needs. Based on this experimental device, a process method that is easy to implement industrially and can efficiently remove ash from catalytic cracking oil slurry is provided. It can remove ash from oil slurry in a short time and at a low cost, which is beneficial to improving the quality of subsequent processed products. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of the oil tank simulation experimental device of the present invention. Detailed Implementation

[0031] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0032] like Figure 1 As shown, the oil tank simulation experimental device for enhancing the settling and deashing effect of oil slurry of the present invention is characterized by including a base 3, a tubular container body 1 set on the base 3, several sampling tubes 2 extending into the center position of the cross-section of the tubular container body 1, a sampling tube valve set at the end of each sampling tube 2, a top end cap 4 set at the top of the tubular container body 1, a temperature measuring system and an outer wall heating system.

[0033] The tubular container body 1 is a vertical structure in the shape of a hollow cylinder or a hollow cuboid, with a height of 1 meter or more, a diameter of 1 decimeter or more, and a length-to-diameter ratio greater than 10.

[0034] The tubular container body 1 is made of stainless steel, glass or transparent resin material by thermoforming.

[0035] The base 3 is a flat rectangular parallelepiped or a flat cylindrical shape, and the base 3 is formed or welded to the tubular container body 1 in one piece.

[0036] The sampling tube 2 is formed or welded to the tubular container body 1 in one piece, and the sampling tube 2 has a hollow structure.

[0037] The temperature measuring system includes a sealed temperature measuring tube 5 extending into the tubular container body 1, and a thermocouple or glass thermometer inserted into the sealed temperature measuring tube 5.

[0038] The aforementioned external wall heating system includes heat tracing heating or radiant heating.

[0039] A method for simulating an oil tank using an enhanced oil slurry settling and deashing device, characterized by comprising the following steps:

[0040] (1) Place the device near a continuous heat source, close all sampling tube valves, open the top end cap 4, and inject clean oil such as diesel, kerosene, petroleum ether, toluene, etc. until the tubular container body 1 is full. After standing for a period of time, open the sampling tube valve at the end of the lowest sampling tube 2, drain the dirty oil, and then close the sampling tube valve.

[0041] (2) Mix the target type of oil slurry to be deashed with a low-viscosity oil that has little impact on subsequent processing at a ratio of 5 to 50. The viscosity of the mixed oil sample at 50°C should be 100 mmHg. 2 For concentrations below 0.01% to 10% of the mixed oil sample, add a settling agent.

[0042] (3) Inject the mixed oil and settling agent into the tubular container body 1, with the liquid level higher than the uppermost sampling tube 2; then cover the top end cap 4, insert the thermocouple or glass thermometer into the sealed temperature measuring tube 5; raise the temperature of the device or the device environment to 50℃~100℃, maintain it for 12h~120h, and open each sampling tube 2 in sequence to collect oil samples from different locations for analysis of ash content, molecular composition, etc.

[0043] (4) Calculate the ash settling rate based on the difference in ash content of samples at different heights;

[0044] (5) Repeat steps (2) to (4) to conduct experiments with different concentrations of settling agent and determine the ash settling rate at different concentrations;

[0045] (6) Based on the settling rate measured in step (5), the settling time and settling time for industrial production are determined by taking into account factors such as settling time and settling agent cost.

[0046] (7) After the experiment is completed, open the sampling tube 2 at the lowest position, drain the remaining oil sample and then close the sampling tube valve; then open the top end cap 4 and inject clean oil such as diesel, kerosene, petroleum ether, toluene, etc. until the tubular container body 1 is full; close the top end cap 4 and wait for the next experiment.

[0047] The technical solution of this invention designs an oil tank simulation experimental device and employs a dilution sedimentation method to reduce the viscosity of the system within the oil tank. A process method was designed and verified to effectively solve the problems of low sedimentation efficiency and unstable deashing effect. Through laboratory experiments and industrial scale-up experiments, it is demonstrated that dilution sedimentation can effectively reduce the encapsulation and complexation of catalyst powder by heavy oil, allowing the positively charged active centers of the sedimentant to better contact and complex with the negatively charged catalyst powder, increasing its weight and achieving a highly efficient sedimentation effect. The concentration of the sedimentant can be adjusted according to the effect, reducing the amount of sedimentant used and maximizing efficiency.

[0048] In the modern petrochemical industry, the importance of various oil storage tanks as raw material storage, intermediate product buffers, and temporary storage sites for finished products in production lines is self-evident. In modern oil processing, oil storage tanks are no longer considered relatively static or homogeneous systems. Dynamic changes constantly occur within them, such as sedimentation, flocculation, and stratification. Furthermore, some production technologies utilize the space of oil storage tanks for operations such as desliming, oil layer separation, and water layer separation.

[0049] Active operations within oil tanks, such as slurry deashing and oil-water separation, as well as passive phenomena like oil stratification and the impact of microbial growth in the aquifer, lack specific experimental methods for simulation. Typically, technicians use data from deashing and separation experiments conducted in small laboratory containers to estimate the conditions of on-site oil tanks. However, based on years of laboratory experience, the results of deashing and separation experiments in small containers differ significantly from on-site data. The main reason for this is that laboratory conditions cannot accurately simulate the impact of the actual height of the oil tank on experimental conditions and operations. Oil tanks are typically on the order of meters to ten meters in height, while the longitudinal height of conventional laboratory containers does not exceed meters, generally only decimeters. Gravity has unpredictable effects on the complex composition of oil products, and these effects are far more significant in the meter- to ten-meter-level oil phase environment than in conventional laboratory containers. For example, in experiments using flocculation principles to deash catalytic cracking slurry, different types of settling agents show similar settling effects in conventional laboratory containers, but the differences are substantial in on-site storage tanks. The main issue is the significant difference in time required to achieve a certain deashing effect; the maximum time difference can reach tens of hours. This is primarily due to the different settling rates of ash in the oil slurry under the combined action of the settling agent and gravity, meaning the ash settles to different heights per unit time. This difference cannot be observed in small laboratory equipment, where ash settles to the bottom of the container within a relatively short time. Such a large time difference significantly impacts the scheduling of deashing operations in oil slurry storage tanks. Therefore, it is necessary to design more reasonable experimental devices and methods that can simulate the real environment of oil tanks.

[0050] Since oil is a liquid, a characteristic of liquids is that mixtures with similar densities tend to form a homogeneous phase, fundamentally because the formation of a homogeneous phase conforms to the trend of entropy increase. However, in actual storage tanks, where heights can reach tens of meters, the complex oil mixtures inside the tank, under the influence of gravity, always exhibit a density gradient distribution trend, with the average density increasing from top to bottom. This effect cannot be reflected in conventional laboratory containers; therefore, the primary objective of designing a simulation of the environment inside an oil tank is to ensure that the container height is comparable to the actual height of the storage tank. Considering the height limitations of most laboratories, the experimental setup should ideally be set at 2 meters or more, not exceeding the laboratory ceiling height or the maximum height achievable for safe manual operation. Furthermore, since modern storage tanks are equipped with heating devices, the experimental setup should also be equipped with temperature monitoring devices to simulate these conditions.

[0051] Experimental apparatus of the present invention:

[0052] The experimental setup consists of a tubular container body 1, a base 3, several sampling tubes 2 and sampling tube valves, and a top end cap 4; its auxiliary devices include a temperature measurement system consisting of a highly sensitive thermocouple and a glass thermometer; and an external wall heating system.

[0053] The tubular container body 1 is a hollow cylinder or hollow cuboid shape, which can be thermoformed from materials such as stainless steel, glass, and transparent resin, or welded from standard stainless steel tubing. It has a vertical structure with a height of 1 meter or more, a diameter of 1 decimeter or more, and a length-to-diameter ratio preferably greater than 10. Stainless steel is generally used, but if it is necessary to observe the stratification within the oil tank, glass or transparent resin can be used for sampling. The diameter of the tubular container body 1 is not limited, usually in the decimeter range. Slender devices have small capacities, require small samples, and are relatively safe.

[0054] The base 3 is a flat rectangular or flat cylindrical shape, and its material should be the same as that of the tubular container body 1, with a weight comparable to that of the tubular container body 1; the base 3 and the tubular container body 1 should be formed in one piece or welded tightly. The function of the base 3 is to keep the device stable and prevent it from tipping over.

[0055] Sampling tube 2 should be integrally formed or welded tightly to the tubular container body 1. Sampling tube 2 has a hollow structure and should extend near the center of the cross-section of the tubular container body 1. There can be one or more sampling tubes 2. The position and number of sampling tubes 2 can be customized according to specific experimental needs. Since the height reaches the level of a real storage tank, sampling ports can be set at different heights according to experimental needs, facilitating the examination of differences between samples at different heights. Sampling tube 2 should extend to the center of the tubular container body 1, where sampling is least affected by the boundary effect of the pipe wall.

[0056] Sampling tube valves should be installed at both ends of each sampling tube. Any type of valve that meets the experimental requirements can be used. Valves are provided for convenient sampling and should be of various types, such as quick-opening valves, high-temperature resistant valves, and needle valves, depending on the experimental needs.

[0057] The top end cap 4 should be the same shape as the tubular container body 1 but shorter, and its material should be the same as the tubular container body 1. The top end cap 4 can be movable or detachable. During the experiment, the top end cap 4 should be tightly fastened to the top of the tubular container body 1 to maintain a sealed state. Depending on the experimental needs, the top end cap 4 may be omitted or opened.

[0058] The temperature measuring system consists of a sealed temperature measuring tube 5, identical in form to the sampling tube 2, and a thermocouple or glass thermometer; during the experiment, the thermocouple or glass thermometer is inserted into the sealed temperature measuring tube 5. The sealed temperature measuring tube 5 is not connected to the interior of the tubular container body 1.

[0059] The external wall heating system can be various forms of heating with heat tracing, radiation heating, etc., or the device can be placed in a temperature-controlled space to simulate the actual operating temperature of the oil tank.

[0060] Example

[0061] This embodiment provides an experimental method for evaluating the deashing effect of different settling agents in a simulated oil tank environment, including the following steps:

[0062] (1) Place the device near a continuous heat source, close all sampling tube valves, open the top end cap 4, and inject clean oil such as diesel, kerosene, petroleum ether, toluene, etc. until the tubular container body 1 is full; after standing for a period of time, open the lowest sampling tube 2, drain the dirty oil, and then close the valve;

[0063] (2) Mix the target type A oil slurry to be deashed with catalytic diesel, coking diesel, etc. at a diesel ratio of 20%. The viscosity of the mixed oil sample at 50°C is 89 mm. 2 / s; The original ash content of the A oil slurry is 1800ppm; Add a settling agent (any additive that uses the principle of flocculation to settle the oil slurry) to the mixed oil sample at a ratio of 500ppm.

[0064] (3) Using the aforementioned experimental apparatus, the oil slurry to be tested and the settling agent are mixed as required and then injected into the tubular container body 1, with the liquid level higher than the uppermost sampling tube 2; then the top cap 4 is covered, and the thermocouple or glass tube thermometer is inserted into the sealed temperature measuring tube 5; the temperature of the apparatus or the ambient temperature of the apparatus is raised to 80°C and maintained for 24 hours, and each sampling tube 2 is opened in sequence to collect oil samples from different locations for analysis of ash content, molecular composition, etc.

[0065] (4) Calculate the ash settling rate based on the difference in ash content of samples at different heights; after sampling, the ash content of the four sampling ports is 200 ppm, so the settling rate can be calculated as (1800-200) ppm / 24 hours × 2 meters, that is, 1600 ppm / 24 hours × 2 meters.

[0066] (5) Repeat steps (2) to (4) to conduct experiments with different flocculant concentrations and determine the ash settling rate at different concentrations; finally, it was determined that when the flocculant concentration was 300 ppm, the settling rate was 1200 ppm / 24 hours × 2 meters, which met the production requirements.

[0067] (6) Based on the settling rate determined in step (5), reduce the ash content of a full tank of 500 m³ oil slurry with a height of about 5 meters to below 200 ppm within 48 hours, and the analysis is qualified;

[0068] (7) After the experiment is completed, open the sampling tube 2 at the lowest position, drain the remaining oil sample and then close the valve; then open the top end cap 4 and inject clean oil such as diesel, kerosene, petroleum ether, toluene, etc. until the tubular container body 1 is full; close the top end cap 4 and wait for the next experiment.

[0069] The process method and oil tank simulation experimental device for enhancing the ash removal effect of oil slurry sedimentation of the present invention are reasonably designed, simple and feasible, and simulate the internal environment of the oil tank as much as possible. The height of the oil container is made to be comparable to that of a real storage tank, which facilitates sampling at different heights to examine the differences in oil composition at different height positions of the oil tank according to experimental needs. Based on this experimental device, a process method that is easy to implement industrially and can efficiently remove ash from catalytic cracking oil slurry is provided. It can remove ash from oil slurry in a short time and at a low cost, which is beneficial to improving the quality of subsequent processed products.

Claims

1. A method for simulating an oil tank using an enhanced oil slurry settling and deashing device, characterized in that: The oil tank simulation experimental device includes a base, a tubular container body set on the base, several sampling tubes extending into the center of the cross-section of the tubular container body, a sampling tube valve set at the end of each sampling tube, a top end cap set at the top of the tubular container body, a temperature measuring system, and an outer wall heating system. The tubular container body is a vertical structure in the shape of a hollow cylinder or a hollow cuboid, with a height of 1 meter or more, a diameter of 1 decimeter or more, and a length-to-diameter ratio greater than 10. The method of the oil tank simulation experimental device utilizing the enhanced oil slurry settling and deashing effect includes the following steps: (1) Place the device near a continuous heat source, close all sampling tube valves, open the top end cap, and inject clean diesel, kerosene, petroleum ether, or toluene clean oil until the tubular container is full. After standing for a period of time, open the sampling tube valve at the end of the lowest sampling tube, drain the dirty oil, and then close the sampling tube valve. (2) Mix the target type of oil slurry to be deashed with a low-viscosity oil that has little impact on subsequent processing at a ratio of 5 to 50. The viscosity of the mixed oil sample at 50°C should be 100 mmHg. 2 For concentrations below 0.01% to 10% of the mixed oil sample, add a settling agent. (3) Inject the mixed oil sample and settling agent into the tubular container body 1, with the liquid level higher than the uppermost sampling tube position; then cover the top end cap, insert the thermocouple or glass thermometer into the sealed temperature measuring tube; raise the temperature of the device or the device environment to 50℃~100℃, maintain it for 12h~120h, and open each sampling tube in sequence to collect oil samples from different positions for ash content and molecular composition analysis; (4) Calculate the ash settling rate based on the difference in ash content of samples at different heights; (5) Repeat steps (2) to (4) to conduct experiments with different concentrations of settling agent and determine the ash settling rate at different concentrations; (6) Based on the settling rate measured in step (5), the settling time and settling time for industrial production are determined by taking into account the settling time and settling agent cost factors. (7) After the experiment is completed, open the sampling tube at the lowest position, drain the remaining oil sample and then close the sampling tube valve; then open the top end cap and inject clean diesel, kerosene, petroleum ether, or toluene clean oil until the tubular container is full; close the top end cap and wait for the next experiment.

2. The method of the oil tank simulation experimental device for enhancing the settling and deashing effect of oil slurry according to claim 1, characterized in that... The tubular container body is made of stainless steel, glass, or transparent resin material through thermoforming.

3. The method of the oil tank simulation experimental device for enhancing the settling and deashing effect of oil slurry according to claim 1, characterized in that... The base is a flat rectangular parallelepiped or a flat cylindrical shape, and the base is formed or welded to the tubular container body in one piece.

4. The method of the oil tank simulation experimental device for enhancing the settling and deashing effect of oil slurry according to claim 1, characterized in that... The sampling tube is formed or welded to the tubular container body in one piece, and the sampling tube has a hollow structure.

5. The method of the oil tank simulation experimental device for enhancing the settling and deashing effect of oil slurry according to claim 1, characterized in that... The temperature measuring system includes a sealed temperature measuring tube extending into the tubular container body, and a thermocouple or glass thermometer inserted into the sealed temperature measuring tube.

6. The method of the oil tank simulation experimental device for enhancing the settling and deashing effect of oil slurry according to claim 1, characterized in that... The aforementioned external wall heating system includes heat tracing heating or radiant heating.

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