Fluidized bed-based sulfur low-temperature atomization and deposition system and method

Abstract

This invention discloses a fluidized bed-based low-temperature sulfur atomization and deposition system and method, relating to the fields of chemical engineering, metallurgy, and environmental protection. The system includes a fluidized bed supply unit, a pneumatic conveying unit, and a high-temperature deposition chamber. The fluidized bed supply unit fluidizes solid sulfur powder; the pneumatic conveying unit carries the sulfur powder in a gas-solid two-phase flow using a carrier gas, conveying it without active heating; the high-temperature deposition chamber heats the gas-solid two-phase flow to above the sulfur vaporization temperature, causing the sulfur powder to vaporize instantaneously. This invention abandons the traditional molten liquid conveying mode, conveying the sulfur in the form of room-temperature solid powder, completely avoiding the risk of pipeline blockage, eliminating the need for heat tracing and insulation, and significantly reducing energy consumption. High-precision linear feed control is achieved by adjusting the carrier gas flow rate, resulting in high system reliability, safe and simple start-up and shutdown, and significantly reduced operating and maintenance costs.

Description

Technical Field

[0001] This invention relates to the fields of chemical engineering, metallurgy and environmental protection, and more specifically to a fluidized bed-based low-temperature sulfur atomization and deposition system and method. Background Technology

[0002] In the chemical, metallurgical, and environmental protection fields (such as Claus process sulfur recovery, sulfuric acid production, and metal sulfide refining), converting solid sulfur into gaseous sulfur vapor is a crucial raw material pretreatment step. Current mainstream technologies generally follow a technical route of "overall preheating and melting - liquid conveying - high-temperature atomization / gasification," with the standard process as follows:

[0003] 1. Melting: Solid sulfur in block or granular form is put into a sulfur melting tank and heated to 130-150℃ (significantly higher than its melting point of about 115-120℃) by means of steam coils or electric heating, so that it is completely transformed into a liquid state.

[0004] 2. Liquid transport and insulation: Liquid sulfur is transported to the reactor (such as a combustion furnace or reaction furnace) via a pumping system and pipeline. To prevent the sulfur from solidifying in the pipeline, the entire transport pipeline must be equipped with a continuous steam or electric heat tracing insulation system to ensure that the sulfur remains in a molten state at all times.

[0005] 3. Atomization and vaporization: Liquid sulfur is transported to the nozzle of the high-temperature reactor, where it is atomized into fine droplets by high-pressure steam or air. The droplets evaporate rapidly in the high-temperature environment of the reactor (usually >1000℃) and participate in the reaction; or they evaporate into sulfur vapor in a dedicated vaporization chamber at a lower temperature (such as the sedimentation chamber, 300-600℃).

[0006] The aforementioned mature processes suffer from a series of interrelated defects stemming from their inherent technical principles: 1. Low energy efficiency and high operating costs Defects: Each batch of sulfur needs to be heated from room temperature (25°C) to a molten state (150°C), a process that requires the absorption of a large amount of sensible heat and latent heat of molten metal. In addition, the transport pipelines, which are tens or even hundreds of meters long, need to continuously consume energy for heat tracing and insulation. This part of the "maintenance heat" cannot be turned off during non-production periods, and is an ineffective continuous energy consumption.

[0007] The root cause is that the thermodynamic path of this process dictates that it is inherently energy-intensive. It requires that sulfur undergo a phase change from solid to liquid before entering the core reaction zone, and that the entire material flow (including the pipe walls) be maintained at a high temperature for an extended period. Heat loss is systematic and unavoidable.

[0008] 2. The system has poor reliability, is prone to blockages, and requires frequent maintenance. Defect manifestation: Any local malfunction in the heat tracing system (such as unstable steam pressure or damage to the heating tape) or a short-term shutdown can easily cause molten sulfur in the pipeline to solidify, resulting in severe pipeline blockage. Unblocking is dangerous, tedious, and time-consuming, seriously affecting production continuity and equipment availability.

[0009] Root cause: This defect stems from the process's instability in its dependence on the material's state. Sulfur's melting and freezing points are very close, and its liquid state is stable only within a narrow temperature range. The process treats this unstable "liquid" state as a necessary condition for transport, making the reliability of the entire system entirely dependent on the absolute perfection of external insulation, which is fragile and difficult to guarantee in engineering practice.

[0010] 3. Complex process control, insufficient feeding stability and precision. Defects: Flow control of liquid sulfur relies on valve and pump adjustments, and is greatly affected by viscosity variations (sensitive to temperature) and pipeline pressure fluctuations, making it difficult to achieve high-precision, high-response feeding. This is a critical bottleneck for advanced reactions requiring precise stoichiometry (such as the synthesis of specific sulfides).

[0011] The root cause is that liquids are continuous-phase fluids, and their flow control is essentially the interception and propulsion of macroscopic fluids, which is difficult to combine with the discrete and measurable characteristics of solid materials.

[0012] 4. Safety hazards and equipment corrosion Defects: If high-temperature molten sulfur leaks from pipes or flanges, it can cause burns and may ignite upon contact with air. Furthermore, high-temperature sulfur is corrosive to many metals, impacting equipment lifespan over long-term operation.

[0013] The root cause is that maintaining a large amount of material under high temperature and high pressure (pumping conditions) for a long time results in a high total amount of energy and hazardous materials contained in the system, which essentially increases the level of safety risk.

[0014] In summary, the core technical challenges faced by existing technologies can be summarized as: how to achieve efficient, stable, and controllable transport and supply of sulfur to the high-temperature reaction zone, while minimizing the high energy consumption, high complexity, and high risk associated with maintaining its liquid state. The significant difficulty in solving this problem lies in the profound contradiction between physicochemical properties and engineering implementation: The contradiction lies in the fact that sulfur must be vaporized efficiently at high temperatures (>444.6℃) to participate in the reaction, but it is also prone to solidification and blockage during transportation due to cooling. Existing technologies employ a "liquefy first, then transport" approach, which essentially uses a complex and energy-intensive intermediate system (melting and insulation system) to forcefully address this contradiction.

[0015] The prevailing mindset in current technology is that traditional solutions always revolve around optimizing "how to better maintain the liquid state," such as developing more efficient heat tracing materials, more precise temperature control systems, and more corrosion-resistant alloy pipes. These improvements are incremental and do not break free from the fundamental paradigm of liquid transportation. Therefore, the aforementioned shortcomings are inherent structural problems of this paradigm and cannot be fundamentally solved within its framework.

[0016] The crux of the problem lies precisely in the need for a paradigm shift: can we find a way to prevent sulfur from becoming liquid before it reaches its vaporization point, thus completely eliminating the need for heat tracing and insulation systems? Summary of the Invention

[0017] In view of this, the present invention provides a fluidized bed-based low-temperature sulfur atomization and deposition system and method, aiming to provide an innovative system that can completely solve the systemic problems of high energy consumption, easy clogging, difficult control, and high risk caused by traditional molten transport methods in high-temperature sulfur reaction processes. Its core lies in the revolutionary coupling of the fluidized stable storage and transport of solid sulfur powder with the terminal instantaneous high-temperature gasification.

[0018] To achieve the above objectives, the present invention adopts the following technical solution: A fluidized bed-based low-temperature sulfur atomization and deposition system includes: A fluidized bed supply unit is used to contain solid sulfur powder and introduce fluidizing gas to make the solid sulfur powder form a fluidized state. A pneumatic conveying unit is connected to the fluidized bed supply unit. The pneumatic conveying unit carries fluidized sulfur powder from the fluidized bed supply unit through a carrier gas to form a gas-solid two-phase flow and conveys it without active heating. A high-temperature deposition chamber is connected to the outlet of the pneumatic conveying unit and is used to receive the gas-solid two-phase flow and heat it to above the sulfur vaporization temperature, so that the sulfur powder is vaporized instantaneously.

[0019] To address the problems of existing technologies, this invention proposes a groundbreaking solution. Its core innovation lies not in optimizing liquid transport, but in completely eliminating the intermediate liquid state and reconstructing the process chain: 1. State Reconfiguration: Sulfur is transported in the form of dry solid powder. Solid powder is stable at room temperature and there is no risk of solidification.

[0020] 2. Conveying paradigm shift: The introduction of fluidized bed technology uses airflow to make solid powder exhibit fluid-like flow characteristics (fluidization), and then uses carrier gas for pneumatic conveying, which solves the engineering problem of continuous and stable conveying of solid materials.

[0021] 3. Optimized Thermodynamic Path: The preheating process is drastically compressed and postponed. Sulfur particles are only directly and efficiently heated by the high-temperature environment the instant they enter the deposition chamber, undergoing a rapid phase transition from solid to liquid to gas or direct sublimation. Energy is used only for gasification itself, avoiding all ineffective heat losses along the way.

[0022] Therefore, the high level of inventiveness of the technical problem solved by this invention lies in its breaking the industry's technical prejudice that sulfur transportation must first be melted. Through synergistic innovation in material state (solid powder), transportation method (fluidized bed pneumatic conveying), and energy injection method (terminal instantaneous gasification), it provides a completely new solution that fundamentally avoids all the structural defects of the original technical paradigm. This not only solves specific problems such as energy consumption, blockage, and control, but also opens up a completely new process route for handling easily solidified materials that require high-temperature gasification.

[0023] Preferably, in the above-mentioned fluidized bed-based sulfur low-temperature atomization and deposition system, the fluidized bed supply unit includes: Fluidized bed containers; A gas distribution plate disposed at the bottom of the fluidized bed container is used to uniformly distribute the fluidizing gas. A fluidizing gas supply system for introducing fluidizing gas into the fluidized bed container; A sulfur powder silo and feeder are used to continuously replenish sulfur powder into the fluidized bed container; The bed monitoring and control system is used to monitor bed pressure drop or material level and automatically adjust the feed rate and fluidizing gas volume.

[0024] Preferably, in the above-mentioned fluidized bed-based sulfur low-temperature atomization and deposition system, the gas distribution plate is a porous sintered metal plate or a wind cap structure; the fluidized gas supply system includes a gas preheater for preheating the fluidized gas to above the sulfur dew point temperature.

[0025] Preferably, in the above-mentioned fluidized bed-based sulfur low-temperature atomization and deposition system, the pneumatic conveying unit includes a Venturi injector or suction nozzle, which is disposed above the fluidized bed layer of the fluidized bed supply unit to introduce carrier gas and generate negative pressure to entrain sulfur powder.

[0026] Preferably, in the above-mentioned fluidized bed-based sulfur low-temperature atomization and deposition system, the high-temperature deposition chamber is a multi-segment independent temperature control structure, which sequentially forms a preheating zone, a rapid vaporization zone, and a uniform temperature zone along the axial direction, and the temperature of each segment can be adjusted independently.

[0027] Preferably, in the above-mentioned fluidized bed-based sulfur low-temperature atomization and deposition system, the outlet of the pneumatic conveying unit enters the high-temperature deposition chamber tangentially or by setting a cyclone separator, so as to generate swirling flow in the gas-solid two-phase flow and prolong the residence time of sulfur powder in the high-temperature zone.

[0028] This invention also provides a fluidized bed-based method for low-temperature sulfur atomization and deposition, comprising the following steps: Step 1: In a fluidized bed, the solid sulfur powder is brought into a fluidized state; Step 2: A carrier gas is used to entrain the fluidized sulfur powder in the fluidized bed to form a gas-solid two-phase flow, which is then transported without active heating. Step 3: Introduce the gas-solid two-phase flow into the high-temperature deposition chamber, so that the sulfur powder is instantly heated and vaporized at high temperature.

[0029] Preferably, in the above-mentioned fluidized bed-based low-temperature sulfur atomization and deposition method, the temperature of the sulfur powder before entering the high-temperature deposition chamber is always lower than its melting point, and the particle size of the sulfur powder is in the range of 80 mesh to 300 mesh.

[0030] Preferably, in the above-mentioned fluidized bed-based low-temperature sulfur atomization and deposition method, the sulfur powder conveying rate is linearly controlled by adjusting the flow rate or pressure of the carrier gas, and the operating temperature range of the high-temperature deposition chamber is 500°C to 900°C.

[0031] Preferably, in the above-mentioned fluidized bed-based low-temperature sulfur atomization and deposition method, the gas-solid two-phase flow has a conveying velocity of 15 m / s to 25 m / s in the conveying pipeline, and the conveying pipeline has no heating or insulation structure throughout.

[0032] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a fluidized bed-based low-temperature sulfur atomization and deposition system and method, which has the following beneficial effects: 1. The energy-saving effect is extremely significant, and the operating cost is greatly reduced. Direct energy saving: It completely eliminates the latent heat and sensible heat required to heat sulfur from room temperature to a molten state (about 150°C), as well as the huge heat loss of maintaining tens of meters of pipeline at a high temperature for a long time. The energy input is concentrated only on the instantaneous vaporization of sulfur powder in the terminal deposition chamber, and the thermal energy utilization rate can be increased from less than 50% in the traditional system to more than 80%.

[0033] Indirect energy saving: The normal temperature conveying pipeline does not require insulation layer and heat tracing system, eliminating the manufacturing energy consumption of this part of the equipment. "It can be used immediately without the need for long-term preheating and insulation of traditional sulfur melting tanks, and the standby energy consumption is almost zero."

[0034] 2. System reliability has achieved a qualitative leap, and maintenance costs have been drastically reduced. The most critical failure mode has been eliminated: because the transport medium is a normal-temperature gas-solid two-phase flow, sulfur has absolutely no possibility of solidification in the pipeline, thus eradicating the persistent problem of pipeline blockage caused by heat tracing failures or shutdowns in traditional processes. System start-up and shutdown become exceptionally simple and safe.

[0035] Reduced equipment complexity: The system eliminates the need for complex steam tracing networks, drainage systems, high-temperature sulfur pumps, and corresponding insulation works, resulting in a simpler system composition, reducing the number of potential failure points by more than 60%, and significantly extending the mean time between failures (MTBF).

[0036] 3. Revolutionary improvement in process control precision and flexibility Feed control achieves gasification precision: By adjusting the flow rate of the carrier gas (with a control response speed in the millisecond range), the sulfur feed rate can be linearly, in real-time, and with high precision, similar to controlling airflow. The precision is an order of magnitude higher than that of traditional liquid sulfur pumping. This opens up possibilities for downstream high-end reactions requiring precise stoichiometry (such as the synthesis of specialty chemicals).

[0037] High operational flexibility: The system's throughput can be quickly adjusted within a wide range (e.g., 30%-100% load) by adjusting the carrier gas volume without affecting the stability of the fluidized bed, and can flexibly adapt to production fluctuations.

[0038] 4. Comprehensive improvement in inherent safety and environmental friendliness Reduced safety risk level: Most areas of the system (feeding, fluidization, conveying) are at low temperature (<80℃) and normal pressure, significantly reducing the risk of fire, burns, and corrosion caused by high-temperature molten sulfur leakage. The stored and conveyed materials are solid powders, which are far less hazardous than high-temperature, high-pressure fluids.

[0039] Environmental benefits: It avoids the generation of trace amounts of odorous and harmful gases such as hydrogen sulfide that may be produced due to localized overheating during traditional sulfur melting processes. The sealed negative pressure or inert gas protection system also reduces the emission of sulfur dust.

[0040] 5. Significant advantages in overall investment and operating costs. Initial investment savings: Although fluidized bed and fine feeding equipment are added, the sulfur melting tank, high-temperature pump, complex heat tracing system and insulation project are eliminated, so the overall equipment investment is comparable or slightly reduced, and the installation is simpler.

[0041] Extremely low operating and maintenance costs: The significant reduction in energy consumption directly lowers major operating costs. No need to deal with blockages, greatly reducing maintenance workload and spare parts consumption (such as heat tracing pipes and high-temperature pump seals). Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0043] Figure 1 The attached figure is a schematic diagram of the fluidized bed-based low-temperature sulfur atomization and deposition system provided by the present invention; Figure 2 The attached figure is a schematic diagram of the fluidized bed-based low-temperature sulfur atomization and deposition method provided by the present invention; Figure 3 The attached figure is a schematic diagram of the gas distribution plate provided by the present invention.

[0044] in: 1- Fluidized bed supply unit; 2- Pneumatic conveying unit; 3- High-temperature sedimentation chamber; 11-Fluidized bed container; 12-Gas distribution plate; 13-Fluidized gas supply system; 14-Sulfur powder silo; 15-Feeder. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, those skilled in the art can make inferences without making creative mistakes. All other embodiments obtained under the premise of creative labor are within the scope of protection of this invention.

[0046] See appendix Figure 1 To be continued Figure 3 This invention discloses a fluidized bed-based low-temperature sulfur atomization and deposition system, comprising: Fluidized bed supply unit 1 is used to contain solid sulfur powder and introduce fluidizing gas to make the solid sulfur powder form a fluidized state. Pneumatic conveying unit 2 is connected to fluidized bed supply unit 1. The fluidized sulfur powder is carried from the fluidized bed supply unit 1 by a carrier gas to form a gas-solid two-phase flow and is conveyed under conditions without active heating. The high-temperature deposition chamber 3 is connected to the outlet of the pneumatic conveying unit 2. It is used to receive the gas-solid two-phase flow and heat it to above the sulfur vaporization temperature, so that the sulfur powder is vaporized instantaneously.

[0047] To further optimize the above technical solution, the fluidized bed supply unit 1 includes: Fluidized bed container 11; The gas distribution plate 12, located at the bottom of the fluidized bed container 11, is used to uniformly distribute the fluidizing gas. Fluidizing gas supply system 13 is used to introduce fluidizing gas into fluidized bed container 11; The sulfur powder silo 14 and the feeder 15 are used to continuously replenish sulfur powder into the fluidized bed container 11. The bed monitoring and control system is used to monitor bed pressure drop or material level and automatically adjust the feed rate and fluidizing gas volume.

[0048] To further optimize the above technical solution, the gas distribution plate 12 is a porous sintered metal plate or a wind cap structure; the fluidizing gas supply system 13 includes a gas preheater for preheating the fluidizing gas to above the sulfur dew point temperature.

[0049] To further optimize the above technical solution, the pneumatic conveying unit 2 includes a Venturi injector or suction nozzle, which is positioned above the fluidized bed layer of the fluidized bed supply unit 1 to introduce carrier gas and generate negative pressure to entrain sulfur powder.

[0050] To further optimize the above technical solution, the high-temperature deposition chamber 3 is a multi-segment independent temperature control structure, which sequentially forms a preheating zone, a rapid vaporization zone and a uniform temperature zone along the axial direction, and the temperature of each segment can be adjusted independently.

[0051] To further optimize the above technical solution, the outlet of the pneumatic conveying unit 2 enters the high-temperature deposition chamber 3 tangentially or by setting a cyclone separator, so as to generate swirling flow in the gas-solid two-phase flow and prolong the residence time of sulfur powder in the high-temperature zone.

[0052] The fluidized bed-based low-temperature sulfur atomization and deposition method provided by this invention includes the following steps: Step 1: In a fluidized bed, the solid sulfur powder is brought into a fluidized state; Step 2: A carrier gas is used to entrain fluidized sulfur powder from the fluidized bed to form a gas-solid two-phase flow, which is then transported without active heating. Step 3: Introduce the gas-solid two-phase flow into the high-temperature deposition chamber 3, so that the sulfur powder is instantly heated and vaporized at high temperature.

[0053] To further optimize the above technical solution, the temperature of the sulfur powder before entering the high-temperature deposition chamber 3 is always lower than its melting point, and the particle size of the sulfur powder ranges from 80 mesh to 300 mesh.

[0054] To further optimize the above technical solution, the conveying rate of sulfur powder is linearly controlled by adjusting the flow rate or pressure of the carrier gas, and the operating temperature range of the high-temperature deposition chamber 3 is 500℃ to 900℃.

[0055] To further optimize the above technical solution, the gas-solid two-phase flow is transported at a speed of 15 m / s to 25 m / s in the pipeline, and the pipeline has no heat tracing or insulation structure throughout.

[0056] In this embodiment, Fluidized bed container 11: Designed as a cylindrical vertical container with a conical bottom to facilitate uniform gas distribution and prevent dead zones. The material is 316L stainless steel or a higher grade corrosion-resistant alloy. Key design parameters (diameter-to-height ratio, cone angle) are calculated using physical property data such as the angle of repose and particle size distribution of sulfur powder to ensure the formation of a stable bubbling or turbulent fluidized bed region.

[0057] Gas distribution plate 12: Located at the bottom of the container, it is the most critical component of this unit. It adopts a multi-layer sintered metal filter plate or wind cap design. Its porosity and pore size are precisely calculated to ensure that the fluidizing gas can pass through the bed uniformly in the form of sufficiently small bubbles, generating a stable fluidization state and avoiding channeling or surging. The pressure drop of the distribution plate is usually designed to be 10%-30% of the bed pressure drop to ensure uniform distribution of fluidizing gas and avoid channeling or surging.

[0058] Sulfur powder silo 14 and feeder 15: Connected to the upstream sulfur powder silo, continuous and precise feeding of the fluidized bed container is achieved through a loss-in-weight scale or screw feeder to maintain stable bed level.

[0059] Fluidizing gas supply system 13: Provides the fluidizing medium (such as N2, Ar, or process inert gas). Before entering the distribution plate, the gas is preheated to slightly above the sulfur dew point temperature (e.g., 50-80°C) by a preheater to prevent powder from agglomerating due to trace amounts of moisture in the gas. The gas flow rate is precisely controlled by a mass flow controller (MFC) to ensure that the fluidizing gas velocity (U) is within the optimal range between the minimum fluidizing velocity (Umf) and the terminal velocity (Ut).

[0060] Bed monitoring and control system: Equipped with a differential pressure transmitter to monitor bed pressure drop in real time, indirectly reflecting material level and fluidization quality. Equipped with radar or RF admittance level gauges for interlocked material level control. All data is connected to a DCS or PLC to achieve automatic closed-loop adjustment of feed rate and fluidizing gas velocity, ensuring the bed is in optimal fluidization condition.

[0061] Pneumatic conveying unit 2: Carrier gas introduction and injection device: The carrier gas (which can be from the same source as the fluidizing gas) is introduced at high speed through a Venturi injector or a specially designed suction nozzle located at a specific height above the fluidized bed. The negative pressure generated by this device smoothly draws the actively moving powder particles on the surface of the fluidized bed into the delivery pipeline. Its installation position and structure have been optimized through CFD simulation to minimize disturbance to the main fluidized bed.

[0062] The pipeline system features short-distance, high-radius-curvature wear-resistant elbows. The pipes are made of smooth-walled ceramic-lined tubing or high-hardness alloy tubing to reduce wear and prevent particle adhesion. A key innovation is that this section of the pipeline requires no insulation or heat tracing because the transported medium is a room-temperature gas-solid two-phase flow. The pipe inclination angle is designed to ensure the transport velocity exceeds the deposition velocity, preventing particle sedimentation.

[0063] Distribution and metering: By adjusting the flow rate and pressure of the carrier gas, the amount of sulfur powder conveyed per unit time can be linearly and precisely controlled. This system has a fast response speed and can achieve real-time linkage with downstream reaction demand signals, with feeding accuracy far exceeding that of liquid pumping systems.

[0064] High-temperature deposition chamber 3: The sedimentation chamber reactor is designed as a vertical cylindrical cavity structure, lined with high-temperature refractory materials (such as corundum or high-purity alumina ceramics). Its volume and aspect ratio are calculated and determined based on the sulfur processing capacity and the residence time required for gasification (usually 1-5 seconds).

[0065] High-efficiency heating and temperature field control: Heating method: Multi-segment independently temperature-controlled silicon molybdenum rods or silicon carbide rods are used for electric heating, dividing the deposition chamber along the axial direction into a preheating zone, a rapid vaporization zone, and a homogenization zone. High-frequency induction heating (suitable for metal-lined reactors) can also be used to achieve faster energy injection.

[0066] Temperature field design: The inlet zone temperature is set above the boiling point of sulfur (444.6℃), such as 500-600℃, to allow the particles to melt rapidly and begin vaporization; the main zone temperature is maintained at 600-900℃ (adjustable according to subsequent reaction requirements) to ensure complete condensation of sulfur vapor and sufficient reactivity. A closed-loop control system is formed using multi-point thermocouples (such as K-type or S-type) and intelligent temperature controllers to ensure that the axial and radial temperature gradients meet process requirements and avoid local overheating or underheating.

[0067] Gas-solid mixing and flow design: The end of the delivery pipe extends into the sedimentation chamber. A tangential inlet or a built-in cyclone separator can be used to generate swirling flow in the gas-solid two-phase flow, extending the residence path of particles in the high-temperature zone, enhancing the gas-solid heat and mass transfer efficiency, and ensuring that even slightly larger particles can be completely vaporized.

[0068] Product output: A sulfur vapor outlet is provided at an appropriate location in the sedimentation chamber. A simple baffle or filter screen is installed at the outlet to prevent a very small number of unvaporized particles from being carried out.

[0069] The specific workflow is as follows: 1. System startup and preparation: First, start the high-temperature deposition chamber heating system and gradually raise it to the preset working temperature (e.g., 650℃) and stabilize it.

[0070] The fluidized bed container is filled with protective gas to replace the air, and then the fluidized gas preheating and supply system is started to loosen the sulfur powder in the bed at a low gas velocity.

[0071] Start the feeder and slowly add sulfur powder into the fluidized bed to the preset level.

[0072] 2. Fluidized bed establishment and stabilization: Gradually increase the fluidizing gas flow rate to the design value, observe the bed pressure drop to ensure stability, and confirm the formation of a uniform fluidized state. Adjust the feed rate to maintain a constant material level.

[0073] The control system automatically fine-tunes the feed and fluidizing gas volume based on the material level and pressure drop signals, enabling the fluidized bed unit to enter an automatic and stable operating state.

[0074] 3. Flow transport and instantaneous vaporization: Turn on the carrier gas and adjust it to the required flow rate. The carrier gas immediately entrains the powder in the fluidized bed into the delivery pipe, forming a continuous gas-solid two-phase flow.

[0075] A gas-solid two-phase flow is injected into the high-temperature deposition chamber at high speed (e.g., 15-25 m / s). Under the combined action of high-temperature radiation and convective heat transfer, the powder particles undergo a rapid phase transition (flash vaporization) of "solid → liquid → gas" in milliseconds, completely transforming into sulfur vapor.

[0076] Sulfur vapor is thoroughly mixed with the carrier gas and any auxiliary reaction gas that may be introduced in the upper temperature equalization zone of the deposition chamber. Once the set temperature and composition are reached, it is continuously discharged from the outlet.

[0077] 4. Operation control and optimization: The core control variables of the entire system are: fluidized bed level (controlling storage capacity), carrier gas flow rate (controlling feed rate), and sedimentation chamber temperature (controlling gasification completeness).

[0078] By changing the carrier gas flow rate, the sulfur feed rate can be rapidly and linearly adjusted. The temperature of each section of the deposition chamber can be optimized according to changes in sulfur particle size distribution and throughput to achieve the lowest energy consumption while ensuring complete gasification.

[0079] 5. Safe parking and maintenance: During normal shutdown, first stop the sulfur feed and carrier gas, and after the material in the conveying pipe is emptied, stop the fluidizing gas. The high-temperature deposition chamber is cooled down according to the procedure.

[0080] Because there is no liquid sulfur in the pipeline, the system can be stopped quickly and safely at any time without worrying about pipeline blockage, and maintenance is simple.

[0081] Example 1: A pilot-scale apparatus for continuous sulfurization reactions in the laboratory was developed. The fluidized bed container has a diameter of 200 mm and a processing capacity of 5-20 kg / h for sulfur powder (particle size 100-200 mesh). The fluidizing gas (N2) flow rate is 20-50 L / min, and the carrier gas (N2) flow rate is 10-30 L / min. The deposition chamber is a 150 mm diameter corundum tube, heated by a three-stage electric furnace with temperatures set at 500℃, 750℃, and 700℃ respectively. Operational results show that the system feed is stable, and the gas exiting the deposition chamber has no solid sulfur residue after condensation, confirming complete gasification. The temperature from the system inlet to the delivery pipeline remains below 60℃, demonstrating significant energy savings. Furthermore, no blockages occurred after dozens of start-ups and shutdowns.

[0082] This technical solution, through the synergistic innovation of the above three subsystems in terms of material state, conveying method and energy injection timing, forms a complete, efficient and robust new process package, providing a disruptive engineering solution for the high-temperature utilization of sulfur and similar easily solidified materials.

[0083] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0084] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A fluidized bed-based low-temperature sulfur atomization and deposition system, characterized in that, include: Fluidized bed supply unit (1), the fluidized bed supply unit (1) is used to contain solid sulfur powder and introduce fluidizing gas to make the solid sulfur powder form a fluidized state; Pneumatic conveying unit (2), which is connected to the fluidized bed supply unit (1), carries fluidized sulfur powder from the fluidized bed supply unit (1) through a carrier gas to form a gas-solid two-phase flow and conveys it under conditions without active heating; The high-temperature deposition chamber (3) is connected to the outlet of the pneumatic conveying unit (2) and is used to receive the gas-solid two-phase flow and heat it to above the sulfur vaporization temperature so that the sulfur powder is vaporized instantaneously.

2. The fluidized bed-based low-temperature sulfur atomization and deposition system according to claim 1, characterized in that, The fluidized bed supply unit (1) includes: Fluidized bed container (11); A gas distribution plate (12) is disposed at the bottom of the fluidized bed container (11) for uniformly distributing the fluidizing gas; A fluidizing gas supply system (13) is used to introduce fluidizing gas into the fluidized bed container (11); A sulfur powder silo (14) and a feeder (15) are used to continuously replenish sulfur powder into the fluidized bed container (11); The bed monitoring and control system is used to monitor bed pressure drop or material level and automatically adjust the feed rate and fluidizing gas volume.

3. The fluidized bed-based low-temperature sulfur atomization and deposition system according to claim 2, characterized in that, The gas distribution plate (12) is a porous sintered metal plate or a wind cap structure; the fluidizing gas supply system (13) includes a gas preheater for preheating the fluidizing gas to above the sulfur dew point temperature.

4. The fluidized bed-based low-temperature sulfur atomization and deposition system according to claim 1, characterized in that, The pneumatic conveying unit (2) includes a Venturi injector or suction nozzle, which is disposed above the fluidized bed layer of the fluidized bed supply unit (1) to introduce a carrier gas and generate negative pressure to entrain sulfur powder.

5. A fluidized bed-based low-temperature sulfur atomization and deposition system according to claim 1, characterized in that, The high-temperature deposition chamber (3) is a multi-segment independent temperature control structure, which forms a preheating zone, a rapid vaporization zone and a uniform temperature zone in sequence along the axial direction. The temperature of each segment can be adjusted independently.

6. The fluidized bed-based low-temperature sulfur atomization and deposition system according to claim 1, characterized in that, The outlet of the pneumatic conveying unit (2) enters the high-temperature deposition chamber (3) tangentially or by setting a cyclone separator, so as to generate swirling flow in the gas-solid two-phase flow and prolong the residence time of sulfur powder in the high-temperature zone.

7. A method for low-temperature atomization and deposition of sulfur based on a fluidized bed, characterized in that, Includes the following steps: Step 1: In a fluidized bed, the solid sulfur powder is brought into a fluidized state; Step 2: A carrier gas is used to entrain the fluidized sulfur powder in the fluidized bed to form a gas-solid two-phase flow, which is then transported without active heating. Step 3: Introduce the gas-solid two-phase flow into the high-temperature deposition chamber (3) so that the sulfur powder is instantly heated and vaporized at high temperature.

8. The method for low-temperature sulfur atomization and deposition based on a fluidized bed according to claim 7, characterized in that, The sulfur powder is kept below its melting point before entering the high-temperature deposition chamber (3), and the particle size of the sulfur powder is in the range of 80 mesh to 300 mesh.

9. A fluidized bed-based low-temperature sulfur atomization and deposition method according to claim 7, characterized in that, The sulfur powder conveying rate is linearly controlled by adjusting the flow rate or pressure of the carrier gas, and the operating temperature range of the high-temperature deposition chamber (3) is 500°C to 900°C.

10. A fluidized bed-based method for low-temperature sulfur atomization and deposition according to claim 7, characterized in that, The gas-solid two-phase flow is transported at a speed of 15 m / s to 25 m / s in the conveying pipeline, and the conveying pipeline has no heat tracing or insulation structure throughout.

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