Vertical multi-stage disc countercurrent hydrothermal pressurizing roasting system and hydrothermal pressurizing roasting method

Abstract

The invention discloses a vertical multi-stage disc countercurrent hydrothermal pressurizing roasting system and a hydrothermal pressurizing roasting method, and belongs to the field of chemical process equipment. Aiming at the problems of uneven temperature distribution, uncontrollable material retention time and difficulty in realizing continuous pressurization operation in the existing roasting equipment, a rotary structure in which multiple stages of large discs and small discs are alternately arranged is constructed, and periodic spiral migration of materials in the radial direction is realized through a bidirectional scraper system. A fixed heating source and rotary heating disc coupling mode is adopted, a dynamic disturbance heat transfer mechanism is formed by combining material periodic turning, and heat transfer uniformity is improved. A reverse flow operation mode of steam from bottom to top is introduced, an enhanced hydrothermal reaction field is constructed in a pressurized environment, and the mass transfer efficiency and the reaction effect are improved. And through a feeding and discharging pressure isolation system, continuous and stable operation of the device under a closed condition is realized. The device realizes the conversion of the roasting process from traditional heat treatment to multi-field coupling reaction control, and has the advantages of high heat transfer efficiency, good reaction uniformity, high continuous degree and the like.

Description

Technical Field

[0001] This invention belongs to the field of chemical technology. Specifically, it is a vertical multi-stage disc countercurrent hydrothermal pressure roasting system and its hydrothermal pressure roasting method. Background Technology

[0002] Calcination processes are widely used in chemical, metallurgical, and catalytic material preparation industries. Existing industrial plants often employ rotary calcining furnaces, where material transport and heating are achieved through cylinder rotation. These devices rely on tilt angle and rotation speed to regulate material movement, making precise control of residence time and distribution difficult, which can lead to incomplete reactions or localized overheating. Furthermore, traditional calcination processes suffer from uneven material-gas contact, limited heat and mass transfer efficiency, and uneven temperature distribution, affecting product quality stability. In addition, existing equipment typically operates under atmospheric pressure, making continuous feeding and discharging difficult in pressurized calcination, thus hindering the enhancement and industrial application of hydrothermal reactions. Therefore, there is an urgent need to develop a novel calcination process and equipment that enables controllable residence time, uniform heat transfer, and continuous pressurized operation. Summary of the Invention

[0003] This invention addresses the shortcomings of existing roasting equipment in terms of heat transfer efficiency, material residence time control, and continuous pressurized operation by providing a vertical multi-stage disc countercurrent hydrothermal pressurized roasting process and its apparatus. Through structural innovation and process coupling, it achieves multi-field enhancement and precise control of the roasting process.

[0004] The technical solution provided by this invention is as follows: A vertical multi-stage disc counter-current hydrothermal pressurized calcination system includes a three-dimensional disc calcination furnace. The top of the furnace is connected to a feed tank via a feed pipe, and the top is also connected to a tail gas recovery system via an exhaust pipe. The bottom is connected to a discharge tank via an exhaust pipe, and the bottom is also connected to a steam supply system via a steam pipe. The three-dimensional disc calcination furnace includes a sealed cylindrical body with a refractory insulation layer on its inner wall. A rotating shaft 47 is located in the middle of the cylindrical body, and the rotating shaft 47 rotates under the drive of a transmission system, alternating between top and bottom. A first type of disc and a second type of disc are fixed and rotate on multiple rotating shafts. Heating devices are fixed below the first type of disc and the second type of disc, respectively. A first type of scraper for conveying material from the outside to the inside is provided above the first type of disc. A first discharge channel is provided on the inner side of the first type of disc. A second type of scraper for conveying material from the inside to the outside is provided above the second type of disc. A second discharge channel is provided on the outer edge of the second type of disc. The material forms a spiral and zigzag composite motion trajectory between the various types of discs. Steam is discharged from the steam outlet pipe from bottom to top.

[0005] Furthermore, the steam supply system includes a steam generator and a flow regulating device. The flow regulating device is used to control the amount of steam transported from bottom to top, so that an appropriate amount of steam forms a countercurrent contact with the material moving from top to bottom.

[0006] Furthermore, the first scraper and the second scraper on the first type of scraper and the second type of scraper have inclination angles of +10 to 60° and -10 to 60°, respectively.

[0007] Furthermore, the radial overlap rate of the first and second scrapers is 20% to 80%.

[0008] Furthermore, the heating device is one or more combinations of an independently adjustable electric radiation heating tube, an electromagnetic induction heating device, or a far-infrared heating device, and the cylinder is also equipped with a thermometer for observing the heating device.

[0009] Furthermore, the feed tank is a pressurized feed tank, and the discharge tank is a slow-release discharge tank. The pressurized feed tank and the slow-release discharge tank achieve continuous feeding and discharging through pressure matching.

[0010] Furthermore, the first type of disk is a large disk, and the second type of disk is a small disk.

[0011] The present invention also provides a hydrothermal pressure calcination method, the method comprising the following steps: (1) The material to be processed is fed into the feed tank under pressure, and the material enters the three-dimensional disc roasting furnace through the feed pipe; (2) Rotate the first type of disc and the second type of disc, as well as the first type of feeding scraper and the second type of feeding scraper. The material moves in a zigzag compound motion on each type of disc under the action of the scraper and moves down the disc step by step along the spiral path. (3) The steam supply system introduces hydrothermal steam from the bottom of the three-dimensional disc roasting furnace, so that the steam and the material form a countercurrent contact and are discharged from the steam outlet pipe; In terms of mass transfer and reaction enhancement, this invention introduces hydrothermal steam at the bottom of the device and allows the steam to flow vertically from bottom to top, forming a stable countercurrent contact system with the material moving from top to bottom. This countercurrent structure can create a coupled distribution of temperature and concentration gradients in space, improving the driving force for mass transfer between the gas and solid phases and thus enhancing the hydrothermal reaction process. Especially under pressurized conditions, the steam density and reactivity are enhanced, which is beneficial to the dealumination, silicon replenishment, and structural rearrangement of molecular sieve materials, thereby significantly improving material performance.

[0012] (4) Start the heating device to heat each level of the discs respectively, so that the material will be heated and undergo hydrothermal reaction under the coupling of conduction and convection; In terms of heat transfer enhancement, a coupled heating structure of "fixed heating device + rotating disk" is adopted. Heating devices are arranged below each level of the disk, heating the disks through thermal radiation or electromagnetic means. The disks then supply heat to the material through heat conduction. Simultaneously, under the action of the scraper, the material undergoes periodic tumbling and redistribution on the disk surface, continuously reconstructing the material layer structure and thus forming a non-steady-state disturbance heat transfer process. This heat transfer method breaks through the traditional heat transfer mode in fixed or rotating beds, which is mainly based on steady-state heat conduction. It makes the heat transfer between particles more uniform, effectively avoiding local overheating or insufficient heat transfer, and improving the overall heat transfer efficiency.

[0013] Each heating device operates and is regulated independently, forming a multi-zone temperature control system; precise control of the reaction atmosphere is achieved by adjusting steam flow and pressure; and intelligent operation of the roasting process is realized through online monitoring and feedback control.

[0014] (5) By adjusting the disc rotation speed, scraper angle and steam flow rate, the residence time and reaction conditions of the material in each stage of the disc are controlled; By adjusting key structural parameters such as the scraper angle (positive 10–60° and negative 10–60°), scraper overlap rate (20%–80%), and disc rotation speed (0.1–10 rpm), a functional relationship between material residence time and equipment structure is established. This transforms the passive statistical distribution of material residence time in the roasting furnace into an adjustable distribution function, thereby achieving precise control of reaction time. Compared to existing rotary roasting furnaces that rely on cylinder inclination angle and rotation speed to adjust residence time, this invention achieves higher precision residence time control, effectively improving reaction uniformity and product consistency.

[0015] (6) After roasting, the material is continuously discharged through the bottom discharge pipe under pressure.

[0016] This invention achieves continuous operation of the roasting process by setting up a pressurized feeding system and a closed discharge system. The feeding end uses a pressurized feeding tank, ensuring pressure matching of the material before it enters the roasting furnace; the discharge end is equipped with a slow-release discharge tank, allowing the material to gradually depressurize during discharge, thereby preventing overall system depressurization. This structure effectively solves the technical problem of continuous feeding and discharging in existing pressurized roasting equipment, enabling the device to operate continuously under stable pressure conditions and improving its industrial application capabilities.

[0017] Furthermore, the disk rotation speed is 0.1 to 10 rpm.

[0018] Furthermore, the calcination process is carried out under pressure of 0.1–1 MPa and temperature of 200–600℃, with a material residence time of 0.5–6 h.

[0019] This invention features a multi-level, alternating arrangement of large and small discs along a vertical direction inside the cylinder. Each disc is connected to a central rotating shaft to form an integrated rotating structure. A first type of scraper is installed on the large discs to convey material from the outside to the inside, while a second type of scraper is installed on the small discs to convey material from the inside to the outside. Through the opposing pushing action of the two types of scrapers, the material forms an alternating "outside-inside-outside" migration path between the various levels of discs, thus constructing a complex flow trajectory in space that couples helical and zigzag motions. This structure breaks through the traditional method of controlling material movement by gravity or tilt angle, achieving active design of the material movement path.

[0020] Compared with the prior art, the present invention has the following beneficial effects: (1) Through the multi-stage disc and scraper coupling structure, the active design and precise control of material residence time can be realized, thereby improving the uniformity of reaction; (2) Improve heat transfer efficiency and eliminate uneven temperature distribution through dynamic disturbance heat transfer mechanism; (3) By constructing an enhanced reaction field through steam countercurrent and pressurized environment, the mass transfer efficiency and reaction degree are improved; (4) By isolating the feeding and discharging system by pressure, continuous and stable operation under pressurized conditions can be achieved; (5) Realize the transformation of the roasting process from the traditional "equipment heating" to "multi-field coupled reaction control".

[0021] In summary, this invention has significant innovations in structural design, heat transfer mechanism, reaction enhancement and operation mode, and is applicable to the efficient hydrothermal calcination process of molecular sieve catalysts and other powder materials, with good prospects for engineering applications. Attached Figure Description

[0022] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is a schematic diagram of the overall process of the vertical multi-stage disc counter-current hydrothermal pressurized calcination device of the present invention. Figure 2 This is a schematic diagram of the overall structure of the vertical multi-stage disc counter-current hydrothermal pressurization calcination device of the present invention; Figure 3 This is a schematic diagram of the coupling structure between the multi-stage discs and the scraper inside the device of the present invention; Figure 4 This is a schematic diagram of the scraper structure in this invention; Figure 5 This is a schematic diagram of the coupling structure of the large disc and its feeding system in this invention; Figure 6 This is a schematic diagram illustrating the movement path and residence time control of materials among multiple disks in this invention. Figure 7 This is a schematic diagram of the hydrothermal reaction process of the present invention, which couples steam countercurrent with material flow. Detailed Implementation

[0023] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0024] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also mean including the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0025] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0026] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "over," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure is flipped, an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented as "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0027] To address the technical problems of uneven temperature distribution, uncontrollable material residence time, and difficulty in achieving continuous pressurized operation in existing roasting equipment, this invention provides a vertical multi-stage disc counter-current hydrothermal pressurized roasting process and its enhanced heat and mass transfer equipment. Utilizing its structural features, it achieves full counter-current contact between materials and steam under pressurized conditions, precisely controls material residence time, improves heat and mass transfer efficiency, ensures product quality stability, and meets the needs of continuous industrial production.

[0028] As shown in Figures 1 to 7, according to the embodiments of this application, a vertical multi-stage disc counter-current hydrothermal pressurization roasting system is proposed. The system includes a feeding tank 1, a three-dimensional disc roasting furnace 2, a discharge tank 3, a tail gas recovery system 4, a spray water circulation pump 5, pipelines, valves, and a PLC control system. The three-dimensional disc roasting furnace also includes a sealed cylinder, a multi-stage rotating disc system, a bidirectional scraper system, a drive system, a heating device, a steam supply system, and a pressurized feeding and discharging system. The three-dimensional disc roasting furnace 2 includes a sealed cylinder 25, which serves as the overall load-bearing and sealing foundation. The multi-stage rotating disc system includes a first type of disc 21 and a second type of disc 22 rotating along multiple rotating shafts. The bidirectional scraper system includes a first type of discharge scraper 23 and a second type of discharge scraper 24, respectively installed above each disc and fixed to the cylinder 25. The drive system drives the rotating disc system to rotate synchronously. The heating device is fixed below the discs to provide a heat source. The steam supply system introduces steam from the bottom of the cylinder, which contacts the material in the opposite direction. The pressurized feeding and discharging system enables continuous feeding and discharging under pressurized conditions. The tail gas recovery system 4 recovers the steam and a small amount of ammonia generated during roasting.

[0029] By adjusting the rotational speed of the rotating disc through the drive system, and in conjunction with the angle and overlap design of the bidirectional scraper system, the spiral motion trajectory of the material on the disc can be flexibly controlled, thereby precisely controlling the total residence time of the material. The segmented temperature control design of the heating device, combined with the coupled heat transfer form of fixed heating tubes and rotating discs, achieves uniform temperature distribution within the furnace, avoiding localized overheating. The steam supply system, in conjunction with the multi-stage disc structure, forms a stable counter-current mass transfer environment, enhancing the hydrothermal reaction effect. The pressure matching and isolation design of the pressurized feeding and discharging system solves the technical challenges of continuous operation under pressurized conditions, improving production efficiency. Thus, the vertical multi-stage disc counter-current hydrothermal pressurized roasting equipment provided in this application, through the synergistic effect of multiple systems, realizes the transformation of the roasting process from traditional heat treatment to multi-field coupled reaction control, effectively solving the technical pain points of existing equipment.

[0030] Specifically, the sealed cylinder includes a cylindrical furnace body, an upper end cover, a lower end cap, and a thermal insulation structure. The cylindrical furnace body is made of low-alloy high-strength steel, with design parameters adapted to pressurized roasting conditions. Symmetrical support legs are installed in the lower part of the furnace body to ensure the stability of the equipment during vertical installation. The upper end cover is connected to the furnace body via a flange, facilitating the maintenance of internal components. The lower end cap is welded to the furnace body to enhance structural strength. The thermal insulation structure uses a composite refractory insulation layer 26, consisting of a high-temperature heat-resistant protective coating, an aluminum silicate fiber module, and an aluminum silicate fiber blanket, arranged sequentially from the inside out. The outer layer is covered with carbon steel, effectively reducing heat loss and preventing direct contact between the high-temperature, high-pressure medium and the cylinder body.

[0031] The material combination is adapted to the working conditions, taking into account both pressure resistance and manufacturing cost. The strength is checked to meet the design pressure requirements. The design of the composite insulation structure reduces the risk of cylinder corrosion and creep, improves energy utilization efficiency, and can compensate for the thermal deformation of the furnace shell to ensure the sealing of the insulation layer.

[0032] Furthermore, all openings in the sealed cylinder are reinforced and checked, including material inlet / outlet, gas inlet / outlet, radiant tube interface, manhole, etc. A reasonable reinforcement design is adopted to ensure the overall pressure bearing reliability of the cylinder and avoid safety hazards caused by local stress concentration.

[0033] The multi-stage rotating disk system includes a rotating shaft, a large disk (first type of disk), and a small disk (second type of disk). The rotating shaft is made of heat-resistant and corrosion-resistant material and is equipped with sliding bearings to compensate for thermal expansion displacement. The large and small disks are arranged alternately along the vertical direction of the rotating shaft and are fixedly connected to the rotating shaft, rotating synchronously. The large disk has a discharge hole 211 (first discharge channel) on its inner side, and the small disk has a discharge channel 222 (second discharge channel) on its edge. The two work together to make the material form a zigzag motion trajectory in the vertical direction. Both the large and small disks are made of heat-resistant stainless steel, which can withstand high-temperature steam corrosion environment.

[0034] The alternating arrangement of large and small discs extends the residence path of materials in the furnace; the selection of heat-resistant materials ensures the service life of the discs in high-temperature steam environments; and the structural and dimensional design of each disc is adapted to the residence time requirements of different roasting processes.

[0035] The bidirectional scraper system includes Type I scrapers and Type II scrapers. Type I scrapers (first-type feeding scrapers) are mounted on a large disc and used to convey materials from the outside to the inside. Type II scrapers (second-type feeding scrapers) are mounted on a small disc and used to convey materials from the inside to the outside. Several scrapers are evenly distributed on each disc. The scrapers are made of corrosion-resistant and wear-resistant material. The scrapers form a set angle with the circumference of the disc (adjustable within the range of 10° to 60°), which is fixed and adjusted by bolts. The scrapers have a certain overlap rate in the radial direction of the disc (adjustable within the range of 20% to 80%). The scrapers adopt an optimized structural design to increase the material flow area and avoid material blockage.

[0036] The reverse pushing design of Type I and Type II scrapers, combined with the rotation of the disc, causes the material to form a spiral motion trajectory on the disc, ensuring full contact between the material and steam; the adjustability of the scraper angle and overlap rate provides a structural basis for precise control of the material residence time; the optimized scraper structure effectively solves the material blockage problem and improves the uniformity of roasting.

[0037] The drive system includes a motor, a reduction mechanism, and a transmission assembly; wherein, the drive system is connected to the rotating shaft through the transmission assembly, driving the rotating shaft to drive the disc to rotate synchronously; the drive system can achieve a wide range of steplessly adjustable speed, and is equipped with a speed monitoring assembly to feed back to the PLC control system, realizing the linkage adjustment of speed and material residence time.

[0038] It adopts a stable and reliable transmission method to meet the process requirements of low-speed disc rotation; the wide range of adjustable speed, combined with scraper parameters, can realize flexible control of material residence time to adapt to the calcination requirements of different molecular sieve catalysts; the PLC linkage control design improves the accuracy of speed regulation and ensures product quality consistency.

[0039] The heating system includes a heating device (such as an electric radiant heating tube), a pressure-bearing sleeve, and a temperature control component 27. The electric radiant heating tube is a fixed structure, with several tubes evenly arranged below each layer of discs, adapted to the disc positions. The total power of the electric radiant heating tubes meets the roasting temperature requirements, exhibiting high electrothermal conversion efficiency. The pressure-bearing sleeve is connected to the cylinder, facilitating maintenance and replacement of the heating tubes under pressurized conditions. The temperature control component employs segmented temperature control, equipped with temperature monitoring elements to provide feedback and adjust the heating power, ensuring temperature control accuracy.

[0040] The coupling design of the fixed heating tube and the rotating disk ensures uniform heating of the disk, thereby guaranteeing consistent material temperature. The segmented temperature control design can accurately allocate energy consumption according to the heat demand of each area, solving the temperature difference problem caused by traditional temperature control. The setting of the pressure-bearing sleeve enables the heating tube to be inspected under pressure, improving the continuity of equipment operation. The electric radiation heating method meets environmental protection requirements, while reserving sufficient power margin to cope with abnormal operating conditions.

[0041] The steam supply system includes a steam inlet, a flow regulating device, and a steam pipeline; wherein, the steam inlet is located at the lower part of the cylinder and deionized water is introduced as the steam source; the flow regulating device is used to control the deionized water introduction rate to ensure stable steam pressure inside the furnace (adjustable within the range of 0.1~1MPa); the steam pipeline cooperates with the multi-stage disc structure to form a countercurrent mass transfer path inside the cylinder.

[0042] The design of deionized water absorbing heat in the furnace to generate superheated steam simplifies the process system and reduces investment costs; the pressurized operating condition design makes it easier for steam to penetrate into the pores of the molecular sieve, promotes hydrothermal reaction, and improves the performance of the molecular sieve; the formation of the countercurrent mass transfer path increases the contact area between the gas and solid phases and the mass transfer driving force, thereby enhancing the hydrothermal reaction effect.

[0043] The pressurized feeding and discharging system includes a feed tank 1, a discharge tank 3, and a pressure regulating component. Both the feed tank and the discharge tank are made of pressure-bearing materials and are designed to be compatible with the operating conditions of the roasting furnace. The feed tank is pressurized with inert gas until it reaches pressure equilibrium with the roasting furnace before feeding material. The discharge tank collects material to a set level and then slowly releases pressure through the pressure regulating component before discharging. The pressure regulating component includes a pressure sensor, a regulating valve, and a purge pipeline to maintain pressure balance among the various components.

[0044] The pressure matching design of the feed tank and discharge tank enables continuous feeding and discharging of the roasting furnace under non-pressure relief conditions, solving the technical problem that traditional pressure roasting equipment is difficult to operate continuously; the slow pressure relief design avoids structural damage to the material due to sudden pressure drop, improving product yield; the setting of the purging pipeline can prevent the material from scaling and clogging in the channel.

[0045] The exhaust gas treatment system 4 includes an exhaust gas absorption tower, a spray water circulation pump, and a pressure regulating valve. The exhaust gas absorption tower absorbs steam and a small amount of ammonia emitted from the roasting furnace. The spray water circulation pump provides circulating absorbent. The pressure regulating valve maintains pressure balance between the exhaust gas absorption tower and the roasting furnace, preventing system pressure fluctuations. The exhaust gas absorption tower design achieves the recovery and reuse of steam and ammonia, with no harmful gases emitted, meeting environmental protection requirements. The use of circulating absorbent reduces water consumption and improves the economics of the process. The interlocking control of the pressure regulating valve ensures the pressure stability of the entire roasting system.

[0046] In addition to the above-mentioned equipment, this application also provides a vertical multi-stage disc countercurrent hydrothermal pressurization roasting process, which includes the following steps: (1) Pretreatment stage: After the equipment is pressure tested and confirmed to be leak-free, the heating device is started to raise the temperature to the set temperature at a reasonable rate, and at the same time, inert gas is introduced to replace the air in the furnace so that the oxygen content meets the process requirements; the molecular sieve catalyst to be roasted is added to the feed tank and pressurized with inert gas to balance the pressure with the roasting furnace; (2) Roasting operation stage: the feed valve is opened and the feed rate is adjusted, and the material is evenly distributed to the top large disc through the feed pipe; the drive system is started and the speed is set, and the material moves down the spiral trajectory step by step under the action of the scraper and the disc; the steam system is started and deionized water is introduced to generate superheated steam with set parameters in the furnace, which comes into countercurrent contact with the material; the process is carried out by PLC. The system monitors each process parameter in real time and dynamically adjusts and optimizes it; (3) Discharge and post-processing stage: the material enters the unloading tank through the bottom disc, and slowly depressurizes and discharges after reaching the set liquid level, and samples are taken to test the product performance; after the operation is completed, inert gas is introduced to purge the residual material in the furnace and clean the inlet and outlet channels.

[0047] This process achieves precise control of material residence time, calcination temperature, and steam pressure through multi-system collaborative control, significantly improving the catalytic activity and thermal stability of molecular sieve products. The product qualification rate and yield are superior to those of traditional processes.

[0048] To facilitate understanding, the technical effects of the equipment and process provided in this application are described below in conjunction with experimental verification results. The core innovations of this application lie in the coupled structure of the multi-stage disc and bidirectional scraper, the heat transfer form of the fixed heating and rotating disc, the enhanced mass transfer under steam countercurrent and pressurized conditions, and the design of the pressurized continuous feeding and discharging system. Through numerical simulation and experimental verification, the equipment's filling rate and thermal efficiency are significantly higher than traditional roasting equipment, with good temperature uniformity within the furnace and precise control of material residence time, fully meeting the requirements of the high-efficiency roasting process for molecular sieve catalysts.

[0049] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A vertical multi-stage disc counter-current hydrothermal pressurized calcination system, characterized in that, The roasting system includes a three-dimensional disc roasting furnace. The top of the furnace is connected to a feed tank via a feed pipe, and the top is also connected to a tail gas recovery system via an exhaust pipe. The bottom is connected to a discharge tank via an exhaust pipe, and the bottom is also connected to a steam supply system via a steam pipe. The furnace is characterized by having a sealed cylindrical body with a refractory insulation layer on its inner wall. A rotating shaft is located in the center of the cylindrical body, and the rotating shaft rotates under the drive of a transmission system. Multiple rotating shafts are alternately fixed from top to bottom. The rotating first and second type of discs are equipped with heating devices fixed below them. The first type of disc has a first type of scraper for conveying material from the outside to the inside, and a first discharge channel is provided on the inner side of the first type of disc. The second type of disc has a second type of scraper for conveying material from the inside to the outside, and a second discharge channel is provided on the outer edge of the second type of disc. The material forms a spiral and zigzag composite motion trajectory between the various types of discs, and steam is discharged from the exhaust pipe from bottom to top.

2. The vertical multi-stage disc counter-current hydrothermal pressurization calcination system as described in claim 1, characterized in that, The steam supply system includes a steam generator and a flow regulating device. The flow regulating device is used to control the amount of steam transported from bottom to top, so that an appropriate amount of steam forms a countercurrent contact with the material moving from top to bottom.

3. The vertical multi-stage disc counter-current hydrothermal pressurization calcination system as described in claim 1, characterized in that, The first scraper and the second scraper on the first type of scraper and the second type of scraper have inclination angles of +10 to 60° and -10 to 60°, respectively.

4. The vertical multi-stage disc counter-current hydrothermal pressurization calcination system as described in claim 3, characterized in that, The radial overlap rate of the first and second scrapers is 20% to 80%.

5. The vertical multi-stage disc counter-current hydrothermal pressurization calcination system as described in claim 1, characterized in that, The heating device is one or more of the following: an independently adjustable electric radiation heating tube, an electromagnetic induction heating device, or a far-infrared heating device. The cylinder is also equipped with a thermometer for observing the heating device.

6. The vertical multi-stage disc counter-current hydrothermal pressurization calcination system as described in claim 1, characterized in that, The feed tank is a pressurized feed tank, and the discharge tank is a slow-release discharge tank. The pressurized feed tank and the slow-release discharge tank achieve continuous feeding and discharging through pressure matching.

7. The vertical multi-stage disc counter-current hydrothermal pressurization calcination system as described in claim 1, characterized in that, The first type of disk is a large disk, and the second type of disk is a small disk.

8. The hydrothermal pressure calcination method of the vertical multi-stage disc countercurrent hydrothermal pressure calcination system as described in any one of claims 1-7, characterized in that, The method includes the following steps: (1) The material to be processed is fed into the feed tank under pressure, and the material enters the three-dimensional disc roasting furnace through the feed pipe; (2) Rotate the first type of disc and the second type of disc, as well as the first type of feeding scraper and the second type of feeding scraper. The material moves in a zigzag compound motion on each type of disc under the action of the scraper and moves down the disc step by step along the spiral path. (3) The steam supply system introduces hydrothermal steam from the bottom of the three-dimensional disc roasting furnace, so that the steam and the material form a countercurrent contact and are discharged from the steam outlet pipe; (4) Start the heating device to heat each level of the discs respectively, so that the material will be heated and undergo hydrothermal reaction under the coupling of conduction and convection; (5) By adjusting the disc rotation speed, scraper angle and steam flow rate, the residence time and reaction conditions of the material in each stage of the disc are controlled; (6) After roasting, the material is continuously discharged through the bottom discharge pipe under pressure.

9. The hydrothermal pressure calcination method of the vertical multi-stage disc countercurrent hydrothermal pressure calcination system as described in claim 8, characterized in that, The disk rotates at a speed of 0.1 to 10 rpm.

10. The hydrothermal pressure calcination method of the vertical multi-stage disc countercurrent hydrothermal pressure calcination system as described in claim 8, characterized in that, The calcination process is carried out under pressure of 0.1–1 MPa and temperature of 200–600℃, with a material residence time of 0.5–6 h.

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