Fluidized bed gas distributor and use method thereof

Abstract

The invention relates to a fluidized bed gas distributor and a use method thereof. The device is arranged in a fluidized bed and comprises a central air passage, a circumferential refractory material masonry, a grid section net, a peripheral air passage, a peripheral air passage air inlet pipe, a central air passage air inlet pipe and a plurality of pressure detection devices, and the circumferential refractory material masonry is of an annular structure consisting of a plurality of refractory materials; an annular peripheral air passage is formed between the circumferential refractory material masonry and the fluidized bed, a central air passage is arranged in the circumferential refractory material masonry, the grid section net is lapped at the upper part of the peripheral air passage, the peripheral air passage air inlet pipe is connected with the peripheral air passage, and the central air passage air inlet pipe is connected with the central air passage. And pressure detection devices are arranged on the peripheral air channel air inlet pipe and the central air channel air inlet pipe. According to the invention, the central and peripheral gas introduction amount and gas pressure change can be controlled respectively, the adjustment mode is more flexible, and various conditions and the problems of bonding, flow loss and material blockage in the operation process of the fluidized bed can be better treated.

Description

Technical Field

[0001] This invention relates to the field of hydrogen metallurgy technology, and more particularly to a fluidized bed gas distributor and its method of use. Background Technology

[0002] Existing fluidized bed distributors for hydrogen metallurgy are screen-shaped steel distributors, which have a relatively short service life in high-temperature hydrogen atmospheres and are difficult to replace. Furthermore, when hydrogen pressure is insufficient or during maintenance, direct reduction of iron can cause it to fall onto the gas distributor and adhere to it, affecting the uniform distribution of gas into the fluidized bed and severely exacerbating adhesion and flow loss. Although the gas is introduced in a uniform distribution, the material in the fluidized bed is spherical, and the airflow resistance is different at the periphery and center, making it easier for it to escape from the periphery, resulting in uneven airflow distribution. At the same time, during the reduction process in the hydrogen metallurgy fluidized bed, the strong adhesion between metal iron at the particle contact interface during reduction can cause adhesion and flow loss, leading to system blockage and making online processing impossible. Summary of the Invention

[0003] In response to the aforementioned technical problems, a fluidized bed gas distributor and its usage method are provided.

[0004] The technical means employed in this invention are as follows: A fluidized bed gas distributor, disposed inside a fluidized bed, includes a central gas channel, a circumferential refractory masonry, a grate mesh, peripheral gas channels, peripheral gas channel inlet pipes, a central gas channel inlet pipe, and several pressure detection devices. The circumferential refractory masonry is a ring structure composed of several refractory materials. A ring-shaped peripheral gas channel is formed between the circumferential refractory masonry and the fluidized bed. The interior of the circumferential refractory masonry is the central gas channel. The grate mesh is placed on top of the peripheral gas channels. The peripheral gas channel inlet pipe is connected to the peripheral gas channels, and the central gas channel inlet pipe is connected to the central gas channel. Pressure detection devices are installed on both the peripheral gas channel inlet pipe and the central gas channel inlet pipe.

[0005] Furthermore, at least four pressure detection devices are evenly arranged along the outer periphery of the central airway inlet pipe, which are used to detect the gas pressure at four points where they intersect in the circumferential direction inside the central airway inlet pipe.

[0006] Furthermore, the ratio of the cross-sections of the peripheral airway to the central airway is 1:9 to 2:8.

[0007] Furthermore, the gas pressure P in the surrounding airway 周 With central airway gas pressure P 中 Satisfy: P 周 -P 中 ≥500pa.

[0008] Furthermore, the material of the grate mesh is high-temperature resistant steel, and the mesh size is less than or equal to 35 mesh.

[0009] Furthermore, the material of the circumferential refractory masonry includes Class B mullite silicon carbide bricks with good high-temperature performance, good thermal shock resistance, and high strength and wear resistance.

[0010] The present invention also discloses a method of using the above-mentioned fluidized bed gas distributor, including: A. During normal operation, the metallization rate of direct reduced iron at different locations or batches at the fluidized bed outlet is detected. When the detected metallization rate fluctuation exceeds the preset value, the gas flow rate at the center and surrounding areas is adjusted. Based on the stability of the detected metallization rate of direct reduced iron at the fluidized bed outlet, the optimal gas flow rate parameter control range is determined. B. During normal operation, monitor the data from the central air inlet pipe pressure detection device in real time. When the pressure difference between the maximum and minimum pressure values ​​exceeds the preset value, it indicates that there is adhesion, loss of flow, and blockage of material in the fluidized bed. Stop the fluidized bed feeding and switch the gas in the surrounding air duct from hydrogen to nitrogen. Open the inspection port of the central air inlet pipe and empty the material; Close the central airway inlet inspection port; The oxygen volume content in the fluidized bed outlet gas is detected. When the oxygen volume content in the fluidized bed outlet gas is lower than the preset value, hydrogen is introduced through the central gas inlet pipe. The surrounding gas duct gas was switched from nitrogen to hydrogen to gradually restore normal fluidized bed production.

[0011] Furthermore, in the monitoring of caking and blockage, when the pressure difference between the maximum and minimum pressure values ​​in the central air inlet pipe exceeds 150 Pa, it indicates that caking and blockage has occurred.

[0012] Compared with the prior art, the present invention has the following advantages: The present invention provides a gas distributor that can control the gas flow rate and pressure changes of the center and the periphery respectively, and the adjustment method is more flexible, better handling various conditions in the fluidized bed operation process and the problems of adhesion, flow loss and blockage. Attached Figure Description

[0013] 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1This is a schematic diagram of the longitudinal section of the gas distributor.

[0015] Figure 2 This is a schematic diagram of the cross-section of a gas distributor.

[0016] In the diagram: 1. Fluidized bed; 2. Gas distributor; 3. Central air duct; 4. Circumferential refractory masonry; 5. Grate mesh; 6. Peripheral air duct; 7. Pressure detector a; 8. Peripheral air duct inlet pipe; 9. Central air duct inlet pipe; 10. Pressure detector b; 11. Pressure detector c; 12. Pressure detector d. Detailed Implementation

[0017] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0020] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0021] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0022] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0023] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0024] like Figure 1 , Figure 2 As shown in the figure, an embodiment of the present invention discloses a fluidized bed gas distributor 2, which is disposed inside a fluidized bed 1. It includes a central air channel, a circumferential refractory material masonry 4, a grate mesh, a peripheral air channel, a peripheral air channel inlet pipe, a central air channel inlet pipe, and several pressure detection devices. The circumferential refractory material masonry 4 is a ring structure composed of several refractory materials. A ring-shaped peripheral air channel 6 is formed between the circumferential refractory material masonry and the fluidized bed. The interior of the circumferential refractory material masonry is the central air channel 3. The grate mesh 5 is placed on the upper part of the peripheral air channel. The peripheral air channel inlet pipe 8 is connected to the peripheral air channel, and the central air channel inlet pipe 9 is connected to the central air channel. Pressure detection devices are provided on both the peripheral air channel inlet pipe and the central air channel inlet pipe.

[0025] Furthermore, a pressure detector a7 is installed on the peripheral airway inlet pipe, and at least four pressure detection devices are evenly arranged along the outer periphery of the central airway inlet pipe. The figure shows pressure detectors b10, c11, and d12 in three directions. A pressure detector e is also installed on the back side, which are used to detect the gas pressure at the four points where the circumference of the central airway inlet pipe intersects.

[0026] Furthermore, the ratio of the cross-sections of the peripheral airway to the central airway is 1:9 to 2:8.

[0027] Furthermore, the gas pressure P in the surrounding airway 周 With central airway gas pressure P 中 Satisfy: P 周 -P 中 ≥500pa.

[0028] Furthermore, the material of the grate mesh is high-temperature resistant steel, and the mesh size is less than or equal to 35 mesh.

[0029] Furthermore, the material of the circumferential refractory masonry includes Class B mullite silicon carbide bricks with good high-temperature performance, good thermal shock resistance, and high strength and wear resistance.

[0030] The present invention also discloses a method of using the above-mentioned fluidized bed gas distributor, including: A. During normal operation, the metallization rate of direct reduced iron at different locations or batches at the fluidized bed outlet is detected. When the detected metallization rate fluctuation exceeds a preset value, the gas flow rate at the control center and surrounding areas is adjusted. Based on the stability of the detected metallization rate of direct reduced iron at the fluidized bed outlet, the optimal gas flow rate parameter control range is determined. In this embodiment, the preset value is ≥5%. The actual adjustment range of the gas flow rate at the control center and surrounding areas is ±100m. 3 / h.

[0031] B. During normal operation, monitor the data from the pressure detection device of the central air inlet pipe in real time. When the pressure difference between the maximum and minimum pressure values ​​exceeds the preset value, it indicates that there is adhesion, loss of flow and blockage of material in the fluidized bed. Stop the fluidized bed feeding and switch the gas in the surrounding air duct from hydrogen to nitrogen. Specifically, the hydrogen flow rate in the central air inlet pipe is gradually reduced by 2% to 30% until it stops.

[0032] Open the inspection port of the central air inlet pipe and empty the material; Close the central airway inlet inspection port; The oxygen volume content in the fluidized bed outlet gas is detected. When the oxygen volume content in the fluidized bed outlet gas is lower than a preset value, hydrogen gas is introduced through the central gas inlet pipe. Specifically, when the oxygen volume content in the fluidized bed outlet gas is <1%, the hydrogen gas flow rate through the central gas inlet pipe is 100 m³ / s. 3 / h increases upwards.

[0033] The surrounding gas duct gas was switched from nitrogen to hydrogen to gradually restore normal fluidized bed production.

[0034] Furthermore, in the monitoring of caking and blockage, when the pressure difference between the maximum and minimum pressure values ​​in the central air inlet pipe exceeds 150 Pa, it indicates that caking and blockage has occurred.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fluidized bed gas distributor, disposed inside a fluidized bed, characterized in that, It includes a central air duct, a circumferential refractory masonry, a grate mesh, a peripheral air duct, a peripheral air duct inlet pipe, a central air duct inlet pipe, and several pressure detection devices. The circumferential refractory masonry is a ring structure composed of several refractory materials. A ring-shaped peripheral air duct is formed between the circumferential refractory masonry and the fluidized bed. The interior of the circumferential refractory masonry is the central air duct. The grate mesh is placed on top of the peripheral air duct. The peripheral air duct inlet pipe is connected to the peripheral air duct, and the central air duct inlet pipe is connected to the central air duct. Pressure detection devices are installed on both the peripheral air duct inlet pipe and the central air duct inlet pipe.

2. The fluidized bed gas distributor according to claim 1, characterized in that, At least four pressure detection devices are evenly arranged along the outer periphery of the central airway inlet pipe, which are used to detect the gas pressure at four points where they intersect in the circumferential direction inside the central airway inlet pipe.

3. The fluidized bed gas distributor according to claim 1, characterized in that, The ratio of the cross-section of the peripheral airway to the central airway is 1:9 to 2:

8.

4. The fluidized bed gas distributor according to claim 1, characterized in that, Peripheral airway gas pressure P 周 With central airway gas pressure P 中 Satisfy: P 周 -P 中 ≥500pa.

5. The fluidized bed gas distributor according to claim 1, characterized in that, The grate mesh is made of high-temperature resistant steel, and the mesh size is less than or equal to 35 mesh.

6. A method of using the fluidized bed gas distributor as described in any one of claims 1-5, characterized in that, include: A. During normal operation, the metallization rate of direct reduced iron at different locations or batches at the fluidized bed outlet is detected. When the detected metallization rate fluctuation exceeds the preset value, the gas flow rate at the center and surrounding areas is adjusted. Based on the stability of the detected metallization rate of direct reduced iron at the fluidized bed outlet, the optimal gas flow rate parameter control range is determined. B. During normal operation, monitor the data from the central air inlet pipe pressure detection device in real time. When the pressure difference between the maximum and minimum pressure values ​​exceeds the preset value, it indicates that there is adhesion, loss of flow, and blockage of material in the fluidized bed. Stop the fluidized bed feeding and switch the gas in the surrounding air duct from hydrogen to nitrogen. Open the inspection port of the central air inlet pipe and empty the material; Close the central airway inlet inspection port; The oxygen volume content in the fluidized bed outlet gas is detected. When the oxygen volume content in the fluidized bed outlet gas is lower than the preset value, hydrogen is introduced through the central gas inlet pipe. The surrounding gas duct gas was switched from nitrogen to hydrogen to gradually restore normal fluidized bed production.

7. The method according to claim 6, characterized in that, In the monitoring of caking and blockage, when the pressure difference between the maximum and minimum pressure values ​​in the central air inlet pipe exceeds 150 Pa, it indicates that caking and blockage has occurred.

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