A gas-conducting reaction device for heating particles

Abstract

The present invention provides a gas-guided reaction device for heating particles, comprising a reactor and a gas collecting chamber, wherein the gas collecting chamber is arranged at the center of the reactor and the two are connected by a gas-guide pipe, wherein the lower portion of the gas-guide pipe extends into the gas collecting chamber and the upper portion extends out of the reactor, and the gas-guide pipe supports the gas collecting chamber. The present invention can enhance heat transfer from the periphery to the center by designing airflow guidance, thereby enhancing heat transfer and achieving rapid heating; and by adjusting the distance between the gas collecting chamber and the outer wall of the reactor, reducing the radial thickness of the material layer, thereby achieving rapid heat transfer between materials, sufficient heating and uniform quality.

Description

Technical Field

[0001] The invention relates to the field of industrial production solid material processing, in particular to a gas-conducting reaction device for heating particles. Background Art

[0002] The heating operation of solid particle materials is a common industrial production process. Due to the thermal reaction characteristics of solid materials and process production conditions, some particles will react to generate a large amount of gas during the heating process, while some processes require the introduction of appropriate gas to meet process requirements. In the heating process of materials, it is sometimes required to strictly control the heating program to reduce the occurrence of side reactions, which requires the control of heat transfer in the reactor. Currently, the commonly used reactor types include fixed bed, rotary kiln, etc.

[0003] Fixed bed reactor is a commonly used intermittent particle heating reactor. After the solid particle material is added to the bed, it is heated by the external heating furnace. Whether to introduce carrier gas can be selected according to the process conditions. The introduction of carrier gas will promote the axial heat transfer process in the bed, but because the heat transfer process from the outer wall to the center is more dependent on the heat conduction process, the temperature difference between the outer wall and the center at the same cross section is large, and the radial temperature difference of the entire bed is large. In order to ensure that the bed materials can reach the set temperature, it is usually adopted to increase the outer wall temperature or extend the heating time, so the energy consumption is high. At the same time, because the outer wall temperature is too high, it will cause the reaction conditions of the outer material to change, so it is difficult to maintain the uniformity of the material quality.

[0004] The rotary kiln is a continuous material heating reactor commonly used in industry. After the material is added to the rotary kiln, it moves from the inlet section to the outlet section along the inclination angle as the kiln body rotates. According to the contact between the heating medium and the particles, it can be divided into direct contact and indirect contact heating. In the direct contact heating mode, the high-temperature flue gas contacts and exchanges heat with the granular material in the kiln body in reverse, directly heating the particles. Due to the limitations of process conditions, some granular materials should try to avoid contact with impurity gases during the heating process, so the application of this type of heating is limited. At the same time, in the direct contact heating process, it is difficult to accurately control the heating process parameters of the material, especially the heating rate and final temperature, so it is difficult to meet the process requirements. The externally heated rotary kiln generally adopts a fixed heating device set outside the rotating kiln body. Due to the need for coordination between dynamic and static equipment, the equipment processing and assembly requirements are high, so the cost is relatively high. In addition, due to the operating characteristics of the rotary kiln, the material filling degree in the kiln body is only about 1 / 3, and there is a large amount of vacant space, and the heat dissipation loss of this part of the space is extremely large, resulting in increased energy consumption. Summary of the invention

[0005] In order to optimize the deficiencies in the above process system, the present invention provides a gas-guided reaction device for heating particles, which has a simple structure, reliable operation, stable effect, low energy consumption, and can achieve controllable heating of particle materials and uniform material quality. The specific technical solution is as follows:

[0006] It includes a reactor and a gas collecting chamber. The gas collecting chamber is arranged at the center of the reactor. The two are connected by an air guide tube. The lower part of the air guide tube extends into the gas collecting chamber and the upper part extends out of the reactor.

[0007] Furthermore, the reactor includes an outer wall, a flange cover, a sealing mechanism and a bottom carrier gas inlet pipeline, wherein the outer wall is arranged on all sides, the flange cover is arranged on the upper part of the outer wall, the sealing mechanism is arranged at the bottom of the outer wall, and the bottom carrier gas inlet pipeline is opened on the lower side of the outer wall.

[0008] Furthermore, the gas collecting cavity is a cavity structure with an opening at the bottom, including side walls arranged on all sides and a top plate arranged on the top.

[0009] Furthermore, the side wall is a porous plate.

[0010] Furthermore, the interval between the reactor and the gas collecting chamber is kept constant.

[0011] Preferably, the reactor and the gas collecting chamber are square structures.

[0012] Preferably, the reactor and the gas collecting chamber are cylindrical structures.

[0013] Preferably, the sealing mechanism is a gate valve.

[0014] Preferably, the sealing mechanism is a gate valve.

[0015] In the above-mentioned gas-guided reaction device provided by the present invention, the heat transfer from the periphery to the center can be enhanced by designing the air flow guide, thereby enhancing heat transfer and achieving the purpose of rapid heating; and by adjusting the distance between the gas collecting cavity and the outer wall of the reactor, the radial thickness of the material layer is reduced, so that the heat transfer between the materials is rapid, the heating is sufficient, and the quality is uniform. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of a gas-conducting reaction device for heating particles provided by an embodiment of the present invention;

[0017] Figure 2 A schematic diagram of a gas collecting chamber and a conduit in a gas-guiding reaction device for heating particles provided in an embodiment of the present invention;

[0018] Figure 3 A schematic diagram of assembling components in a gas-conducting reaction device for heating particles provided by an embodiment of the present invention;

[0019] Figure 4 A schematic diagram of an embodiment of a gas-conducting reaction device for heating particles provided by the present invention, in which the external heating device is a cylindrical furnace.

[0020] In the figure: 1 / 11 - reactor; 2 / 12 - gas collecting chamber; 3 / 13 - air guide tube; 4 - side wall; 5 / 15 - top plate; 6 / 16 - flange cover plate; 7 - outer wall; 8 / 18 sealing mechanism; 9 / 19 - bottom carrier gas inlet pipeline, 10 / 20 - external heating device. DETAILED DESCRIPTION

[0021] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0022] like Figure 1 , Figure 3 As shown, the present embodiment provides a gas-conducting reaction device for heating particles, comprising a reactor 1 and a gas collecting chamber 2 installed in an external heating device 10. The reactor 1 is vertically arranged, and the processing material should be selected according to the process conditions. A certain degree of fit should be maintained with the external heating device 10 to meet the heating requirements. At the same time, the effects of heat preservation and thermal deformation of the reactor on the external heating device 10 should be considered. The cross-sectional shape of the reactor 1 can be square, rectangular or circular, and the reactor 1 should be processed tightly to ensure that there is no gas leakage.

[0023] Specifically, the present embodiment provides a gas-conducting reaction device for heating particles, comprising a reactor 1 and a gas collecting chamber 2, wherein the gas collecting chamber 2 is arranged at the central position inside the reactor 1, and the reactor 1 and the gas collecting chamber 2 are connected by a gas-conducting tube 3, wherein one end of the gas-conducting tube 3 extends to the inside of the gas collecting chamber 2, and the other end of the gas-conducting tube 3 extends to the outside of the reactor 1; particles to be treated by heating are arranged between the reactor 1 and the gas collecting chamber 2, and the reactor 1 is also provided with a through hole that cooperates with a carrier gas inlet pipe 9; the carrier gas is transmitted to the particles to be treated by heating between the reactor 1 and the gas collecting chamber 2, and an external heating device 10 (for example, a heating furnace) is arranged outside the reactor 1, and the gas generated by the heating of the carrier gas or the particles to be treated by heating flows between the particle materials to cause heat transfer by convection heat transfer; and at least part of the carrier gas or the gas generated by the heating of the particles to be treated by heating flows into the gas collecting chamber 2 in the radial direction of the reactor 1, and is discharged to the outside of the reactor 1 through the gas-conducting tube 3.

[0024] The lower end of the reactor 1 should consider the material unloading method, adopt a closing structure, and install a sealing mechanism 8 with sealing performance at the bottom, including but not limited to a gate valve, a plug valve, etc. The top cover of the reactor 1 is connected by a flange, which is a flange cover plate 6 to ensure sealing. Moreover, the bottom of the gas collecting chamber is similar to the outer contour of the reactor, which is a closing structure, and the lower part is open to facilitate the cleaning of materials mixed in the cavity; the top plate of the gas collecting chamber has no holes, that is, the airflow will not enter the gas collecting chamber through the top plate.

[0025] Specifically, Figure 1 , Figure 2 , Figure 3 As shown, the reactor 1 includes a first shell and a second shell, the upper cross-sectional shape of the first shell (for example, the upper rectangular parallelepiped) is the same as the lower cross-sectional shape of the first shell, the upper cross-sectional shape of the second shell (for example, a shell corresponding to a trapezoidal side) is the same as the lower cross-sectional shape of the first shell, and the lower cross-sectional shape of the second shell is the shape of the upper cross-sectional shape of the second shell reduced according to a predetermined ratio; the upper part of the first shell is provided with a through hole matching the air duct, and the air duct is sealed and connected to the through hole in the upper part of the first shell; the through hole in the side wall of the second shell is sealed and connected to the carrier gas inlet pipe, and the bottom of the second shell is sealed. The gas collecting chamber 2 includes a third shell and a fourth shell, the upper cross-sectional shape of the third shell is the same as the lower cross-sectional shape of the third shell, the upper cross-sectional shape of the fourth shell is the same as the lower cross-sectional shape of the third shell, and the lower cross-sectional shape of the fourth shell is the shape of the upper cross-sectional shape of the fourth shell reduced according to a predetermined ratio; the upper part of the fourth shell is provided with a through hole cooperating with the air guide pipe, and the side wall of the third shell is composed of an air guide surface, and the upper surface of the third shell is composed of a closed surface; the lower part of the third shell is an opening, the upper part of the fourth shell is an opening, and the lower part of the third shell is connected to the upper part of the fourth shell, and the side wall of the fourth shell is also composed of an air guide surface; the lower surface of the fourth shell is an opening.

[0026] Among them, the above-mentioned gas-guiding surface can be formed by splicing porous sieve plates, or by pasting gas-permeable materials on a frame with an open side wall to form the gas-guiding surface; it can also be arranged according to different needs that the gas-guiding surface is made of replaceable materials with different gas-guiding apertures, so as to better meet various industrial needs. As a preferred embodiment, the gas collecting chamber is welded by porous sieve plates, and the diameter of the small holes on the sieve plates should be smaller than the particle size. The top plate of the gas collecting chamber is a non-perforated plate, and an air guide pipe is connected to the center of the gas collecting chamber. The air guide pipe extends to the center of the gas collecting chamber, and the upper end passes through the reactor top cover and is connected to the fan. A gas supply pipe is installed on the bottom side wall of the reactor for inputting carrier gas.

[0027] Based on the above-mentioned size arrangement, the particles to be treated by heating between the reactor 1 and the gas collecting chamber 2 have a constant interval between the first shell and the third shell, corresponding to the radial distance between the reactor 1 and the gas collecting chamber 2, which is more conducive to forming a longitudinal airflow and can hold more particles to be treated by heating; and the second shell and the fourth shell adopt the above-mentioned size layout to form a closing structure, which is more conducive to the discharge of particles to be treated by heating. The lower surface of the four shells is open, and the carrier gas is introduced from the side wall, which can be more conducive to the introduction of gas, forming pressure on the gas collecting chamber, and promoting the gas to be discharged from the air guide tube 3, which is more conducive to the particles to be treated by heating to continuously form an airflow inside the gas collecting chamber 2 along the radial direction.

[0028] Among them, the gas collecting chamber 2 is located at the center of the reactor 1, and the preparation material is determined by the process conditions. The gas collecting chamber 2 is a porous cavity structure with a peripheral wall formed by splicing porous sieve plates to form a side wall 4. The outer contour of the gas collecting chamber 2 and the outer wall 7 of the reactor 1 should maintain a constant interval in the range of 5-30 cm, which should be determined according to the process conditions and material properties. The bottom of the gas collecting chamber 2 is similar to the outer contour of the reactor 1, which is a closed structure, and the lower part is open to facilitate the cleaning of materials mixed in the cavity. The top plate 5 of the gas collecting chamber 2 is a steel plate structure, and the air guide pipe 3 extends from the top plate 5 of the gas collecting chamber 2 into the gas collecting chamber 2 and is welded to the gas collecting chamber 2. The airflow will not enter the gas collecting chamber 2 through the top plate 5. The purpose of the air guide pipe 3 is to export the gas in the gas collecting chamber 2 out of the reactor 1 and pass through the flange cover plate 6 of the reactor 1 upward. The air guide pipe 3 should be designed according to the process conditions, and the pipe diameter should be designed so that the outlet airflow velocity does not exceed 20m / s. The air guide pipe 3 also supports the gas collecting chamber 2.

[0029] Taking a typical particle catalyst calcination process as an example, the operation of a gas-conducting reaction device for particle heating provided in this embodiment is described as follows:

[0030] Solid particles are loaded from the upper part of the reactor, and the loading position is in the middle area between the reactor and the gas collecting chamber. When loading, pay attention to the uniform distribution of particles along the gas collecting chamber, and the loading position in the reactor is flush with the top plate of the gas collecting chamber. After the reactor is sealed, check the air tightness and prepare for heating. The carrier gas is input from the gas pipe at the bottom of the reactor, and the fan connected to the air guide pipe is turned on to keep the pressure in the reactor constant. Turn on the heating furnace, complete the heating according to the predetermined requirements, heat the heating to the set temperature, and observe the temperature of the material layer in the tower through the temperature controller to ensure that it is carried out according to the normal heating procedure. Since the solid particles release a large amount of gas during the calcination process, the power of the fan connected to the carrier gas inlet pipe 9 is adjusted in time through the pressure display in the tower, and the generated gas is led out from the conduit in time. After the reaction is completed, stop heating and continue to cool down with carrier gas, and adjust the fan power to adapt to the pressure changes in the reactor. When the material drops to room temperature, stop the carrier gas, open the bottom blind plate and the plug valve, and unload the material from the bottom of the reactor.

[0031] This embodiment provides the working principle of the gas-conducting reaction device:

[0032] The solid particles in the reactor 1 receive heat and heat up mainly by heat conduction, convection and radiation. Heat is transferred from the outer wall 7 of the reactor 1 to the peripheral particles close to the wall, and the peripheral particles transfer heat to the central area mainly by heat conduction, which has a very slow heat transfer rate. The outer wall 7 of the reactor 1 forms a high-temperature wall under the action of the external heating device 10, which radiates heat to the internal materials. Since radiation heat transfer is greatly affected by temperature, the intensity of radiation heat transfer is not high under most working conditions. The heat transfer caused by the flow of gas generated by the carrier gas or particles between the particle materials is convective heat transfer, which becomes the main way to regulate the temperature field distribution of particles in the reactor. Since the airflow usually flows in the axial direction, the axial temperature distribution of the particles in the fixed bed is relatively uniform, but the radial difference is large. In order to reduce the radial temperature difference, this embodiment adjusts the gas flow direction to gather the airflow from the surrounding to the center, and promotes radial heat transfer through the radial flow of the airflow, so that the particle materials in the bed are heated evenly. The gas in the gas collecting cavity 2 is drawn out by the air guide pipe 3 under its own pressure or the attraction of external vacuum.

[0033] The application occasion of this embodiment is the solid particle heating process accompanied by air flow. The air flow can be an additional gas to provide an inert atmosphere, a raw gas participating in the reaction, a newly generated gas during the heating of the particles, or a combination of these gases. The solid is in a granular state, and will not stick or turn into other states that are not conducive to the passage of air flow when heated. The particles are accumulated in the bed layer, and the bed layer porosity is 0.2-0.6, ensuring that the gas can pass smoothly. The heat source of the system comes from an external heating source, and the final effect is that the outer wall 7 of the reactor 1 forms a stable heat source and can transfer heat internally.

[0034] The workflow of this embodiment is as follows:

[0035] Solid particles are loaded from the upper part of the reactor 1, and the loading position is in the middle area between the reactor 1 and the gas collecting chamber 2. When loading, pay attention to the uniform distribution of particles along the gas collecting chamber 2, and the loading position in the reactor 1 is flush with the top plate 5 of the gas collecting chamber 2. After the reactor 1 is sealed, check that the air tightness is correct and prepare for heating. Input the carrier gas from the bottom carrier gas inlet pipeline 9, and turn on the fan connected to the air guide pipe 3 to keep the pressure in the reactor 1 constant. Turn on the heating device, raise the electric furnace to the set temperature through the program heating, and observe the temperature of the material layer in the tower through the temperature controller to ensure that the normal heating program is followed. Since the solid particles release a large amount of gas during the calcination process, the fan power is adjusted in time through the pressure display in the tower, and the generated gas is led out from the air guide pipe 3 in time. After the reaction is completed, stop heating and continue to cool down with carrier gas, and adjust the fan power to adapt to the pressure changes in the reactor 1. When the material drops to room temperature, stop the carrier gas, open the sealing mechanism 8, and unload the material from the bottom of the reactor 1.

[0036] Example 1

[0037] like Figure 1-3 As shown, the external heating device 10 is a square furnace, so the cross-section of the reactor 1 is designed to be rectangular, the lower part is a shrinking structure, the inclination angle is 45°, the outlet is a rectangular tube, and a gate valve is installed, and a blind plate is provided under the gate valve. The gas collecting chamber 2 is a rectangular structure, and the side wall 4 of the gas collecting chamber 2 is 15 cm away from the inner wall of the reactor 1. The gas collecting chamber 2 is welded by a porous sieve plate, and the diameter of the small holes on the sieve plate should be smaller than the particle size. The top plate 5 of the gas collecting chamber 2 is a non-perforated plate, and the center is connected to an air guide pipe 3, which extends to the center of the gas collecting chamber 2, and the upper end passes through the flange cover plate 6 of the reactor 1 and is connected to the fan. The bottom side wall of the reactor 1 is installed with a bottom carrier gas inlet pipeline 9 for inputting carrier gas.

[0038] In this embodiment, since the temperature is high and corrosive gases are released during the reaction, the reactor, gas collecting chamber and gas guide tube are all made of 304 stainless steel; by adopting the above technical scheme of this embodiment, the material heating time is greatly shortened, the power consumption is reduced, and the quality of the generated products is uniform, which can achieve the goal of energy saving and efficiency improvement.

[0039] Example 2

[0040] like Figure 4 As shown, the external heating device 20 is a cylindrical furnace, the reactor 11 is a tubular structure, installed vertically, with a round tube connected to the bottom after the bottom is narrowed, and a gate valve is installed at the bottom. The gas collecting chamber 12 is a porous round tube, the bottom is a narrowed structure with a round opening, and the top is a non-perforated top plate 15. The top plate 15 of the gas collecting chamber 12 has a hole in the center and is welded with an air guide tube 13, and the upper end of the air guide tube 13 passes through the flange cover plate 16 of the reactor 11; the bottom side wall of the reactor 11 is installed with a bottom carrier gas inlet pipeline 19 for inputting carrier gas; the bottom of the reactor 11 is installed with a sealing mechanism 18.

[0041] The beneficial effects of this embodiment are:

[0042] 1. The heating rate of the granular materials in the reactor is accelerated, reducing the heating time;

[0043] 2. The radial temperature difference of the granular materials in the reactor is reduced to avoid uneven heating of the materials;

[0044] 3. Reduce heating power consumption and have energy-saving effect;

[0045] 4. Only the reactor is modified to reduce the processing difficulty.

[0046] The above are preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A gas-conducting reaction device for heating particles, characterized in that: include: A reactor and a gas collecting chamber, wherein the gas collecting chamber is arranged at the center of the reactor, the reactor and the gas collecting chamber are connected by an air duct, one end of the air duct extends to the inside of the gas collecting chamber, and the other end of the air duct extends to the outside of the reactor; particles to be treated by heating are arranged between the reactor and the gas collecting chamber, and the reactor is also provided with a through hole that cooperates with a carrier gas inlet pipe; the carrier gas is transmitted to the particles to be treated by heating between the reactor and the gas collecting chamber, and a heating furnace is arranged outside the reactor, and the gas generated by the heating of the carrier gas or the particles to be treated by heating flows between the particle materials to cause heat transfer by convection heat transfer; and at least part of the carrier gas or the gas generated by the heating of the particles to be treated by heating flows into the gas collecting chamber in the radial direction of the reactor and is discharged to the outside of the reactor through the air duct; The reactor comprises an outer wall, a flange cover, a sealing mechanism and a bottom carrier gas inlet pipeline, wherein the outer wall is arranged on all sides, the flange cover is arranged on the upper part of the outer wall, the sealing mechanism is arranged on the bottom of the outer wall, and the bottom carrier gas inlet pipeline is opened on the lower side of the outer wall; The gas collecting cavity is a cavity structure with an opening at the bottom, including side walls arranged on all sides and a top plate arranged on the top; The side wall is a porous plate, so that at least part of the carrier gas or the gas generated by the particles to be treated by heating flows into the gas collecting cavity in the radial direction of the reactor, and the top plate of the gas collecting cavity has no holes.

2. The gas-conducting reaction device according to claim 1, characterized in that: The distance between the reactor and the gas collecting chamber in the radial direction is kept constant.

3. The gas-conducting reaction device according to claim 1, characterized in that: The reactor and the gas collecting chamber are square structures.

4. The gas-conducting reaction device according to claim 1, characterized in that: The reactor and the gas collecting chamber are cylindrical structures.

5. The gas-conducting reaction device according to claim 1, characterized in that: The sealing mechanism is a gate valve; or the sealing mechanism is a gate valve.

6. The gas-conducting reaction device according to any one of claims 1 to 5, characterized in that: The reactor comprises a first shell and a second shell, wherein the upper cross-sectional shape of the first shell is the same as the lower cross-sectional shape of the first shell, the upper cross-sectional shape of the second shell is the same as the lower cross-sectional shape of the first shell, and the lower cross-sectional shape of the second shell is a shape obtained by reducing the upper cross-sectional shape of the second shell according to a predetermined ratio; The upper part of the first shell is provided with a through hole cooperating with an air duct, and the air duct is sealed and connected to the through hole in the upper part of the first shell; the through hole in the side wall of the second shell is sealed and connected to the carrier gas inlet pipe, and the bottom of the second shell is sealed.

7. The gas-guided reaction device according to claim 6, characterized in that: The gas collecting chamber comprises a third shell and a fourth shell, the upper cross-sectional shape of the third shell is the same as the lower cross-sectional shape of the third shell, the upper cross-sectional shape of the fourth shell is the same as the lower cross-sectional shape of the third shell, and the lower cross-sectional shape of the fourth shell is a shape obtained by reducing the upper cross-sectional shape of the fourth shell according to a predetermined ratio; The upper part of the fourth shell is provided with a through hole cooperating with the air guide pipe, and the side wall of the third shell is composed of an air guide surface, and the upper surface of the third shell is composed of a closed surface; the lower part of the third shell is an opening, the upper part of the fourth shell is an opening, and the lower part of the third shell is connected to the upper part of the fourth shell, and the side wall of the fourth shell is also composed of an air guide surface; the lower surface of the fourth shell is an opening.

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