Graded heterogeneous fixed bed gasifier

Abstract

The invention discloses a graded heterogeneous fixed bed gasifier, which comprises: a pressure-bearing shell, the top of which is provided with a material inlet, the bottom of which is provided with a slag outlet, the pressure-bearing shell is provided with a gasifying agent inlet, and the upper part of the side wall of the pressure-bearing shell is provided with a first synthesis gas outlet; the fire grate is arranged at the lower part of the pressure-bearing shell, an air outlet channel in the radial 0.7-0.8 D of the fire grate is a central channel, the rest air outlet channels are edge channels, and the ratio of the central channel to the edge channels is (2-3): 1. The ratio of the center channel to the edge channel in the fire grate is changed, the ventilation capacity of the center channel of the fire grate is increased, the flame height of the fire grate is increased, and then the height of a gasification bed layer in a hearth and the handling capacity of raw materials are increased.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon-containing material gasification, and more specifically, to a hierarchical heterogeneous fixed bed gasifier. Background Art

[0002] The design concept of the grate in the traditional pressurized fixed bed gasifier is to evenly distribute the gasifier and form a uniform gasification gas flow field in the coal seam, so that the gasification reaction in the raw material layer can be fully carried out. During the operation of the traditional pressurized fixed bed gasifier, the grate generally discharges gas evenly, and the height of each axial bed layer in the furnace is basically constant. When the diameter of the gasifier is fixed, the processing capacity of the raw material is limited, which is not suitable for large-scale production of the device. Summary of the invention

[0003] An object of the present invention is to solve at least the above problems and to provide at least the advantages which will be described hereinafter.

[0004] Another object of the present invention is to provide a graded non-uniform fixed bed gasification furnace, which increases the height of the gasification bed in the furnace and the amount of raw material processed by changing the ratio of the central channel to the edge channel in the grate, increasing the ventilation volume of the central channel of the grate, and increasing the flame height of the grate.

[0005] In order to achieve these objectives and other advantages of the present invention, a hierarchical heterogeneous fixed bed gasifier is provided, comprising:

[0006] A pressure shell, with a material inlet at the top and a slag outlet at the bottom, the pressure shell is provided with a main gasifying agent inlet and an auxiliary gasifying agent inlet, the main gasifying agent inlet is provided at the bottom of the pressure shell, the auxiliary gasifying agent inlet is provided at the side wall of the pressure shell, and a first synthesis gas outlet is provided at the upper part of the side wall of the pressure shell;

[0007] The grate is arranged at the lower part of the pressure shell, the air outlet channel within the radial direction of 0.7-0.8D of the grate is the central channel, and the remaining air outlet channels are edge channels. The air volume ratio between the central channel and the edge channels is 2-3:1, wherein the main gasification agent inlet is connected to the grate.

[0008] Preferably, the inner wall of the pressure-bearing shell is provided with a heat insulation layer, and the heat insulation layer is a membrane-type water-cooled wall structure.

[0009] Preferably, the auxiliary gasifying agent inlet is located at one side of the pressure-bearing shell and is connected to a gasifying agent distributor.

[0010] Preferably, a horizontal partition is provided in the grate, the central channel is located above the partition, and the edge channel is located below the partition;

[0011] The main gasification agent inlet includes a first steam port and a second steam port, the first steam port is connected to a first steam inlet pipe, the end of the first steam inlet pipe vertically extends into the grate and is located below the partition, the pressure shell is provided with a second steam port, the second steam port is connected to a second steam inlet pipe, the diameter of the second steam inlet pipe is smaller than the diameter of the first steam inlet pipe, the end of the second steam inlet pipe vertically passes through the first steam inlet pipe and the partition and extends above the partition, and the vertical edges of the first steam inlet pipe and the second steam inlet pipe are coaxially arranged with the grate.

[0012] Preferably, the ratio of the distance between the gasifying agent distributor and the top of the grate to the diameter of the grate is 0.5-1.5:1.

[0013] Preferably, the air intake of the auxiliary gasifying agent inlet accounts for 10-30% of the total air volume.

[0014] Preferably, a plurality of temperature sensors are provided at intervals above and below the side wall of the pressure-bearing shell.

[0015] Preferably, a second synthesis gas outlet is provided at an upper portion of the side wall of the pressure-bearing shell, and the second synthesis gas outlet is connected to a second gas collecting pipe.

[0016] Preferably, the second gas collecting pipe comprises an annular pipe connected to the second synthesis gas outlet, the annular pipe is provided with a plurality of pipe segments connected at intervals, the pipe segments are arranged vertically downward, wherein the diameter ratio of the annular pipe to the grate is 0.6-0.8:1.

[0017] The present invention has at least the following beneficial effects:

[0018] First, the gasifier enters the main gasifier inlet and the auxiliary gasifier inlet in two ways respectively. The gasifier at the main gasifier inlet increases the flame intensity at the center of the furnace and significantly improves the bed penetration; the gasifier at the auxiliary gasifier inlet is sprayed toward the center of the furnace along the radial direction of the furnace to enhance the flame intensity around the furnace; with the cooperation of the central flame and the peripheral flame, the height of the gasification bed can be significantly increased, and the gasification reaction time can be increased, so as to achieve the purpose of increasing the raw material processing capacity and realize the large-scale device.

[0019] Second, the present invention increases the ventilation volume of the center channel of the grate and the flame height of the grate by changing the ratio of the center channel to the edge channel in the grate, thereby increasing the height of the gasification bed in the furnace and the processing capacity of raw materials.

[0020] Third, the requirements for raw materials are reduced. The particle size range can be expanded to 0-100mm. Raw materials such as coal or biomass with poor thermal stability can be gasified, avoiding the raw materials from being easily pulverized by heat. There is no possibility of excessive bed pressure difference, which is safer.

[0021] Fourth, the present invention can not only realize the separate supply of gasifying agent to the center channel and the edge channel by arranging the partition, the first steam port, the first steam inlet pipe, the second steam port, and the second steam inlet, but also can realize the adjustment of the air volume ratio between the center channel and the edge channel by adjusting the air intake volume in the first steam inlet pipe and the second steam inlet pipe.

[0022] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of a hierarchical heterogeneous fixed bed gasifier according to one of the technical solutions of the present invention;

[0024] Figure 2 This is a schematic structural diagram of a grate described in one of the technical solutions described in the present invention. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0026] like Figure 1 and 2 As shown, the present invention provides a hierarchical heterogeneous fixed bed gasifier, comprising:

[0027] A pressure shell 1, with a material inlet 11 at the top and a slag outlet 12 at the bottom, a main gasifying agent inlet and an auxiliary gasifying agent inlet 15 at the pressure shell 1, the main gasifying agent inlet is arranged at the bottom of the pressure shell 1, the auxiliary gasifying agent inlet 15 is arranged at the side wall of the pressure shell 1, and a first synthesis gas outlet 13 is arranged at the upper part of the side wall of the pressure shell 1;

[0028] The grate 3 is arranged at the lower part of the pressure shell 1. The air outlet channel within the radial direction 0.7-0.8D of the grate 3 is the central channel, and the remaining air outlet channels are edge channels. The air volume ratio between the central channel and the edge channels is 2-3:1, wherein the main gasification agent inlet is connected to the grate.

[0029] In this technical solution, the internal space of the pressure-bearing shell 1 is a furnace 4. The shape of the pressure-bearing shell 1 is set according to the existing technology. The center of the grate 3 is the center of the circle. The air outlet channel within the radial range of 0.7-0.8D from the center of the circle is the central channel, and the other air outlet channels are edge channels. The larger the proportion of the central channel, the higher the flame height. The working principle of the gasifier: the carbon-containing block material enters the gasifier through the material inlet, and is transformed into ash slag accompanied by a complex redox reaction, and passes through the drying layer, the retorting layer, the gasification layer, and the ash layer in turn (the space in the furnace 4 is divided into a drying layer, a retorting layer, a gasification layer, and an ash layer according to the reaction conditions and material changes). The ash layer) moves downward, and the rotation of the grate 3 drives the scraper to break the ash, and then the ash falls to the slag outlet 12 under the action of its own gravity and is discharged from the gasifier; the gasifying agent (such as steam, oxygen, CO2) enters the main gasifying agent inlet and the auxiliary gasifying agent inlet 15 in two ways, among which the gasifying agent at the main gasifying agent inlet is distributed by the grate 3 and enters the furnace 4 from bottom to top and contacts and reacts with the carbon-containing blocks in the central area of ​​the furnace 4 in reverse. The gasifying agent enters the furnace 4 and reacts with the carbon-containing blocks to be converted into a synthesis gas mainly composed of CO, H2, and CH4, which is entrained with tar and other substances distilled out of the gasifier through the first synthesis gas outlet 13.

[0030] By adopting this technical solution, the present invention increases the ventilation volume of the central channel of the grate 3 and the flame height of the grate 3 by changing the air volume ratio of the central channel and the edge channel in the grate 3, thereby increasing the height of the gasification bed in the furnace 4 and the processing capacity of raw materials; the gasifier enters the main gasifier inlet and the auxiliary gasifier inlet 15 respectively in two ways, and the gasifier in the main gasifier inlet increases the flame intensity in the center of the furnace 4 and significantly improves the bed permeability; the gasifier in the auxiliary gasifier inlet 15 is sprayed radially toward the center of the furnace 4 along the furnace 4, thereby enhancing the flame intensity around the furnace 4; with the cooperation of the central flame and the peripheral flame, the height of the gasification bed can be significantly increased, and the gasification reaction time can be increased, so as to achieve the purpose of increasing the raw material processing capacity and realize the large-scale device.

[0031] In another technical solution, a heat insulating layer 2 is provided on the inner wall of the pressure-bearing shell 1, and the heat insulating layer 2 is a membrane-type water-cooled wall structure.

[0032] In another technical solution, the auxiliary gasifying agent inlet 15 is located in the pressure shell 1 and is connected to the gasifying agent distributor 5 on one side thereof. This technical solution is adopted to facilitate the gasifying agent to enter the furnace 4 through the auxiliary gasifying agent inlet 15 .

[0033] In another technical solution, a horizontal partition 20 is provided in the grate 3, the central channel is located above the partition 20, and the edge channel is located below the partition 20;

[0034] The main gasification agent inlet includes a first steam port 14 and a second steam port 21, the first steam port 14 is connected to a first steam inlet pipe, the end of the first steam inlet pipe vertically extends into the grate 3 and is located below the partition 20, the second steam port 21 is connected to a second steam inlet pipe, the diameter of the second steam inlet pipe is smaller than the diameter of the first steam inlet pipe, the end of the second steam inlet pipe vertically passes through the first steam inlet pipe and the partition 20 and extends above the partition 20, the vertical sides of the first steam inlet pipe and the second steam inlet pipe are both coaxially arranged with the grate 3, the top ends of the first steam inlet pipe and the second steam inlet pipe are open, a through hole is provided in the center of the partition 20, the diameter of the through hole is slightly larger than the diameter of the second steam inlet pipe so that the partition can rotate relative to the second steam inlet pipe (the air volume ratio of the central channel to the edge channel can be 2 to 3:1 by adjusting the air volume of the first steam port and the second steam port). By adopting this technical solution, the present invention can not only realize the separate supply of gasifying agent to the center channel and the edge channel by setting a partition, a first steam port 14, a first steam inlet pipe, a second steam port 21, and a second steam inlet, but also can realize the adjustment of the air volume ratio between the center channel and the edge channel by adjusting the air intake volume in the first steam inlet pipe and the second steam inlet pipe.

[0035] In another technical solution, the ratio of the distance between the gasifying agent distributor 5 and the top of the grate 3 to the diameter of the grate 3 is 0.5-1.5:1, and taking the grate 3 with a diameter of 3.2 m as an example, the height of the gasifying agent distributor 5 from the grate 3 is 1.6-4.8 m. This technical solution can effectively increase the height of the gasification layer.

[0036] In another technical solution, the air intake of the auxiliary gasification agent inlet 15 accounts for 10-30% of the total gas volume. When the coal type changes or load adjustment occurs, the gas volume can be adjusted in time by adjusting the valve. This technical solution improves gasification performance.

[0037] In another technical solution, the side wall of the pressure shell is provided with a plurality of temperature sensors 16 at intervals above and below. This technical solution is adopted to detect the actual temperature at different heights in the gasifier, and the optimal process conditions are controlled according to the actual temperature (the temperature is controlled by adjusting the amount of steam added to the gasifying agent and controlling the speed of the grate), so as to achieve the purpose of reducing consumption.

[0038] In another technical solution, a second syngas outlet 17 is provided on the upper part of the side wall of the pressure shell, and the second syngas outlet 17 is located on one side of the pressure shell 1 and is connected to a second gas collecting pipe. With this technical solution, the present invention discharges the high-temperature syngas in the gasifier by setting the second syngas outlet 17 for heat recovery; it can be used to control the temperature of the dry distillation layer (control the amount of syngas discharged from the second syngas outlet 17) to achieve the maximum tar by-product.

[0039] In another technical solution, the second gas collecting pipe includes an annular pipe connected to the second synthesis gas outlet 17, and a plurality of pipe segments are connected to the annular pipe at intervals, and the pipe segments are arranged vertically downward, wherein the diameter ratio of the annular pipe to the grate 3 is 0.6-0.8:1, the annular pipe is arranged coaxially with the grate 3, and the lower end of the pipe segment is open. With this technical solution, the present invention realizes the concentration of the central flame edge and the peripheral flame edge by arranging the annular pipe and the pipe segment, balances the temperature of the upper part of the gasification bed, and helps the raw materials at the flame edge to move downward.

[0040] The number of equipment and processing scale described here are used to simplify the description of the present invention. Applications, modifications and variations of the staged heterogeneous fixed bed gasifier of the present invention will be obvious to those skilled in the art.

[0041] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A hierarchical heterogeneous fixed bed gasifier, characterized in that: include: A pressure shell, with a material inlet at the top and a slag outlet at the bottom, the pressure shell is provided with a main gasifying agent inlet and an auxiliary gasifying agent inlet, the main gasifying agent inlet is provided at the bottom of the pressure shell, the auxiliary gasifying agent inlet is provided at the side wall of the pressure shell, and a first synthesis gas outlet is provided at the upper part of the side wall of the pressure shell; The grate is arranged at the lower part of the pressure shell, the air outlet channel within the radial direction of 0.7-0.8D of the grate is the central channel, and the remaining air outlet channels are edge channels. The air volume ratio between the central channel and the edge channels is 2-3:1, wherein the main gasification agent inlet is connected to the grate.

2. The hierarchical heterogeneous fixed bed gasifier according to claim 1, characterized in that: The inner wall of the pressure-bearing shell is provided with a heat insulation layer, and the heat insulation layer is a membrane-type water-cooled wall structure.

3. The hierarchical heterogeneous fixed bed gasifier according to claim 1, characterized in that: The auxiliary gasifying agent inlet is located at one side of the pressure-bearing shell and is connected to a gasifying agent distributor.

4. The hierarchical heterogeneous fixed bed gasifier according to claim 3, characterized in that: A horizontal partition is provided in the grate, the central channel is located above the partition, and the edge channel is located below the partition; The main gasification agent inlet includes a first steam port and a second steam port, the first steam port is connected to a first steam inlet pipe, the end of the first steam inlet pipe vertically extends into the grate and is located below the partition, the pressure shell is provided with a second steam port, the second steam port is connected to a second steam inlet pipe, the diameter of the second steam inlet pipe is smaller than the diameter of the first steam inlet pipe, the end of the second steam inlet pipe vertically passes through the first steam inlet pipe and the partition and extends above the partition, and the vertical edges of the first steam inlet pipe and the second steam inlet pipe are coaxially arranged with the grate.

5. The hierarchical heterogeneous fixed bed gasifier according to claim 3, characterized in that: The ratio of the distance between the gasifying agent distributor and the top of the grate to the diameter of the grate is 0.5 to 1.5:

1.

6. The hierarchical heterogeneous fixed bed gasifier according to claim 3, characterized in that: The air intake of the auxiliary gasifying agent inlet accounts for 10-30% of the total air volume.

7. The hierarchical heterogeneous fixed bed gasifier according to claim 1, characterized in that: A plurality of temperature sensors are arranged at intervals above and below the side wall of the pressure-bearing shell.

8. The hierarchical heterogeneous fixed bed gasifier according to claim 7, characterized in that: A second synthesis gas outlet is provided at the upper portion of the side wall of the pressure-bearing shell, and the second synthesis gas outlet is connected to a second gas collecting pipe.

9. The hierarchical heterogeneous fixed bed gasifier according to claim 8, characterized in that: The second gas collecting pipe includes an annular pipe connected to the second synthesis gas outlet, and a plurality of pipe segments are connected to the annular pipe at intervals, and the pipe segments are arranged vertically downward, wherein the diameter ratio of the annular pipe to the grate is 0.6-0.8:1.

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