Coal gasification system for ceramic production

Abstract

The utility model discloses a coal gasification system for ceramic production, and belongs to the technical field of ceramic production. The coal gasification system comprises a gasification furnace, a cyclone separation mechanism, a waste heat recovery mechanism and a cloth bag dust removal mechanism which are sequentially connected, the gasification furnace is a small-volume gasification furnace with the gas production rate smaller than or equal to 10 kNm < 3 > / h, and the waste heat recovery mechanism comprises an air preheater and a kettle type heat exchanger. The hot coal gas separated by the cyclone separation mechanism is cooled by an air preheater and a kettle type heat exchanger in sequence; wherein a discharge port of a hot coal gas channel in the kettle type heat exchanger is connected with a feed port of the cloth bag dust removal mechanism; and gas outlets of the cloth bag dust removal mechanism are directly connected with gas inlets of the ceramic firing kiln in a one-to-one correspondence manner through pipelines. According to the scheme, the productivity of the gasification furnace used by the coal gasification system is optimally designed, and a one-to-one gas supply mode between the gasification furnace and the ceramic sintering kiln is designed, so that not only is the flexibility of gas supply adjustment of a single sintering kiln improved, but also a waste heat recovery mechanism in the coal gasification system is simplified.

Description

Technical Field

[0001] This utility model relates to the field of ceramic production technology, and more specifically, to a coal gasification system for ceramic production. Background Technology

[0002] As a traditional high-energy-consuming industry, the ceramics industry relies on gasifiers to provide hot gas for its kilns. Currently, the ceramic sintering process depends on centralized gas supply from large-capacity gasifiers. Specifically, these large-capacity gasifiers supply gas to multiple sintering kilns simultaneously. However, the construction period for these large-capacity gasifiers is long, and the temperature and pressure of the hot gas used in each individual sintering kiln cannot be adjusted independently. Furthermore, when the gas supply from a large-capacity gasifier fails, multiple ceramic sintering kilns must shut down and wait. Therefore, the gasification system used in ceramic production has poor system flexibility.

[0003] In addition, in the existing large-volume coal gasification furnace production, multiple heat exchange processes are required for the hot coal gas at around 900°C coming out of the gasifier, and the cooling process is relatively complex. For example, Chinese Patent Application No. 2018109588360 discloses a coupled coal gasification system, comprising a gasification system, a waste heat recovery system, a dust removal system, and a fly ash circulation system connected in sequence. The gasification system includes a fluidized bed gasifier and an entrained flow gasifier, with the entrained flow gasifier connected downstream of the fluidized bed gasifier. The waste heat recovery system includes a waste heat boiler, a preheater, a steam drum, and a waste heat recovery unit, connected in sequence. The steam drum is bidirectionally connected to the entrained flow gasifier, the waste heat boiler, and the waste heat recovery unit, and is also connected to the fluidized bed gasifier and the entrained flow gasifier via the preheater. The gasification system also includes a cyclone mixer, which is connected to the output end of the fluidized bed gasifier and the input end of the entrained flow gasifier. A gasification burner is installed at the upper end of the entrained flow gasifier, and the fly ash circulation system is connected to the gasification burner. In this application, the hot coal gas discharged from the fluidized bed gasifier needs to pass through multiple waste heat recovery mechanisms, and a steam drum needs to be set up for steam buffering and circulation, resulting in a relatively complex overall structure. Utility Model Content

[0004] 1. Technical problems to be solved

[0005] This utility model aims to provide a coal gasification system for ceramic production. The solution optimizes the capacity of the gasifier used in the coal gasification system and designs a one-to-one gas supply mode between the gasifier and the ceramic sintering kiln. This not only improves the flexibility of gas supply adjustment for a single sintering kiln, but also simplifies the waste heat recovery mechanism in the coal gasification system.

[0006] 2. Technical solutions adopted

[0007] To achieve the above objectives, the technical solution provided by this utility model is as follows:

[0008] This utility model provides a coal gasification system for ceramic production. The system includes a gasifier, a cyclone separator, a waste heat recovery mechanism, and a bag filter dust collector connected in sequence. The gasifier has a gas production capacity of ≤10 kNm³. 3 The small-capacity gasifier with a capacity of / h includes a waste heat recovery mechanism consisting of an air preheater and a kettle heat exchanger connected together. The hot coal gas separated by the cyclone separator is cooled sequentially by the air preheater and the kettle heat exchanger. The outlet of the hot coal gas channel in the kettle heat exchanger is connected to the inlet of the bag filter. The gas outlet of the bag filter is directly connected to the gas inlet of the ceramic firing kiln through a pipeline. Each gasifier supplies gas to a single ceramic firing kiln.

[0009] Furthermore, the air preheater and the autoclave heat exchanger are bidirectionally connected; the outlet end of the cooling medium circuit in the autoclave heat exchanger is connected to the inlet end of the cooling medium circuit in the air preheater to provide steam to the air preheater; the gasifier is connected to the outlet end of the cooling medium circuit in the air preheater through a pipeline to provide gasifying agent to the gasifier.

[0010] Furthermore, the dust outlet of the bag filter is connected to the raw material inlet of the ceramic firing kiln via a pipe.

[0011] Furthermore, the dust outlet of the bag filter is connected to the feed inlet of the ball mill, which is used to mix fly ash with ceramic raw materials. The discharge outlet of the ball mill is connected to the raw material inlet of the ceramic firing kiln.

[0012] Furthermore, the dust outlet of the bag filter dust collector is connected to the feed inlet of the ball mill in sequence through a metering pump, a dust hopper, a disc feeder, and a dust outlet.

[0013] Furthermore, the gas outlet of the bag filter is connected to the burners in the ceramic firing kiln via a pipeline.

[0014] Furthermore, the material outlet at the bottom of the cyclone separator is connected to the gasifier to return the solid particles separated by the cyclone separator to the gasifier.

[0015] Furthermore, the gasifier's feed inlet is connected to the raw coal conveying mechanism for feeding coal into the gasifier.

[0016] Compared with the prior art, the technical solution provided by this utility model has the following advantages:

[0017] (1) This utility model optimizes the gas production of the gasifier by designing an optimized gas production capacity of ≤10kNm³. 3A small-capacity gasifier with a per-hour output. By reducing the gas production of a single gasifier, the requirements for subsequent cooling stages can be reduced, allowing the use of a kettle-type heat exchanger instead of the aforementioned shell-and-tube heat exchanger, economizer, steam drum, and other equipment, resulting in a more compact coal gasification system. Furthermore, the one-to-one connection between the gasifier and the ceramic firing kiln enables a one-to-one gas supply mode between the two, allowing for independent adjustment of the temperature and pressure of the hot coal gas used in each sintering kiln, thus improving the system flexibility of the coal gasification system used in ceramic production.

[0018] (2) This utility model further integrates the coal gasification system with the ceramic production system. Specifically, the gas outlet and dust outlet of the bag filter are connected to the gas inlet and raw material inlet of the ceramic firing kiln through pipelines, respectively. On the one hand, the bag filter filters the crude coal gas, which then enters the ceramic firing kiln as fuel. On the other hand, after dust removal by the bag filter, the hot coal gas and by-product fly ash in the crude coal gas are separated. The obtained fly ash can be directly used as raw material for ceramic production. The nitrogen and sulfur compounds in the coal gas enter the ceramic firing system, which can meet the pollutant emission standards of the ceramic production industry. In addition, the fly ash contains ≥60% carbon, which can play a role in combustion in the ceramic firing system.

[0019] (3) This utility model further optimizes the design of the connecting pipeline between the dust outlet of the bag filter and the ceramic firing kiln. Specifically, the dust outlet of the bag filter is connected to the feed inlet of the ball mill in sequence through a metering pump, an ash silo, and a disc feeder. Among them, fly ash is transported to the ash silo by the metering pump and then to the ball mill by the disc feeder. The conveying efficiency and economy of this conveying method are better than the combination of conventional silo pumps and continuous conveying pumps. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the coal gasification system for ceramic production in an embodiment of this utility model.

[0021] Label Explanation:

[0022] 1. Raw coal conveying mechanism;

[0023] 2. Gasification furnace;

[0024] 3. Cyclone separation mechanism;

[0025] 4. Air preheater;

[0026] 5. Kettle heat exchanger;

[0027] 6. Baghouse dust collection system;

[0028] 7. Metering pump;

[0029] 8. Gray warehouse;

[0030] 9. Disc feeder;

[0031] 10. Ball mill;

[0032] 11. Ceramic firing kiln. Detailed Implementation

[0033] To further understand the content of this utility model, a detailed description of this utility model will be provided in conjunction with the accompanying drawings and embodiments.

[0034] The structures, proportions, and sizes illustrated in the accompanying drawings are merely for illustrative purposes and to aid those skilled in the art in understanding and reading the invention. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed in this utility model. Furthermore, terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and not intended to limit the scope of implementation. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0035] This embodiment provides a coal gasification system for ceramic production. The system includes a gasifier 2, a cyclone separator 3, a waste heat recovery mechanism, and a bag filter dust collector 6 connected in sequence. The gasifier 2 has a gas production capacity of ≤10 kNm³. 3 The small-capacity gasifier with a capacity of / h includes a waste heat recovery mechanism comprising an air preheater 4 and a kettle heat exchanger 5 connected together. The hot coal gas separated by the cyclone separator 3 is cooled sequentially by the air preheater 4 and the kettle heat exchanger 5. The outlet of the hot coal gas channel in the kettle heat exchanger 5 is connected to the inlet of the bag filter 6. The gas outlet of the bag filter 6 is directly connected to the gas inlet of the ceramic firing kiln 11 through a pipeline. Each gasifier 2 is used to supply gas to a single ceramic firing kiln 11.

[0036] This example optimizes the gas production per unit time of gasifier 2, i.e., its capacity, with a gas production rate ≤10 kNm³. 3 Gasifier 2, with a gas production rate of / h per unit time, is referred to as a small-capacity gasifier. Existing large-capacity gasifiers have a gas production rate >10 kNm³. 3A gasification system typically requires two or more cooling stages per hour. Existing cooling processes generally combine waste heat recovery equipment such as air preheaters, shell-and-tube heat exchangers, economizers, and steam drums. By reducing the gas production per unit time of a single gasifier, the requirements for the waste heat recovery mechanism can be reduced. This allows the use of a vessel heat exchanger 5 to replace the aforementioned shell-and-tube heat exchangers, economizers, and steam drums, resulting in a more compact coal gasification system. Furthermore, in existing coal gasification systems, after the hot coal gas passes through the bag filter 6, subsequent cooling stages are relatively numerous to facilitate gas storage and longer-distance transportation. Generally, the gas needs to pass through a gas cooler and then be pressurized. The temperature, pressure, and calorific value of the gas obtained from this process are designed for general industrial applications, and the process is relatively complex and produces condensate. The hot coal gas obtained from this type of gasification system also requires preheating and depressurization before entering the ceramic firing kiln 11. This invention combines a coal gasification system with a ceramic production system. The crude coal gas output from the gasifier 2 enters a cyclone separator 3, which separates solid particles from the crude coal gas. The resulting crude coal gas, at approximately 900°C and containing fly ash, is separated by the cyclone separator 3. The solid particles separated in the cyclone separator 3 are mainly incompletely gasified coal powder. Due to the low density of fly ash, it enters the subsequent waste heat recovery mechanism along with the hot coal gas. The crude coal gas is cooled by the waste heat recovery mechanism, filtered by a bag filter 6, and then enters the ceramic firing kiln 11 as fuel. Compared with existing coal gasification systems, the hot coal gas processing flow is significantly simplified.

[0037] Furthermore, the gas outlet of the bag filter 6 is directly connected to the gas inlet of the ceramic firing kiln 11 via a pipeline, with each gasifier 2 supplying gas to a single ceramic firing kiln 11. By designing a one-to-one gas supply mode between the gasifier and the roller kiln used for ceramic firing, the requirement for the unit capacity of a single gasifier 2 is further reduced. In existing ceramic firing processes, large-capacity gasifiers are generally used to centrally supply gas to multiple ceramic firing roller kilns simultaneously. The temperature and pressure of the hot gas used in a single sintering kiln cannot be adjusted individually. When the gas supply from the large-capacity gasifier fails, multiple kilns need to shut down and wait, resulting in poor system flexibility of the gasification system used in ceramic production. In addition, the construction period for large-capacity gasifiers is long. In summary, the design of this embodiment can improve the system flexibility of the hot gas supply system for ceramic firing kilns and shorten the construction period of the gasification system used in ceramics.

[0038] Specifically, the air preheater 4 and the autoclave heat exchanger 5 are bidirectionally connected; the outlet end of the cooling medium circuit in the autoclave heat exchanger 5 is connected to the inlet end of the cooling medium circuit in the air preheater 4, providing steam to the air preheater 4; the gasifier 2 is connected to the outlet end of the cooling medium circuit in the air preheater 4 via a pipeline, providing gasifying agent to the gasifier 2. The steam generated by the autoclave heat exchanger 5 enters the air preheater 4, serving as the raw material for the cooling medium circuit of the air preheater 4. The steam exchanges heat with hot coal gas in the air preheater 4 to generate gasifying agent, thus achieving higher thermal energy utilization of this waste heat recovery mechanism and eliminating steam exhaust.

[0039] More specifically, the dust outlet of the bag filter 6 is connected to the raw material inlet of the ceramic firing kiln 11 via a pipeline. After dust removal by the bag filter 6, the hot coal gas and by-product fly ash in the crude coal gas are separated. The dust content in the crude coal gas is ≤10mg / Nm³, and the obtained fly ash can be directly used as raw material for ceramic production. The nitrogen and sulfur oxides in the coal gas enter the ceramic firing system, meeting the emission standards for pollutants in the ceramic production industry. Furthermore, the carbon content in the fly ash is ≥60%, which can play a role in combustion in the ceramic firing system. In summary, this simplifies the resource utilization of fly ash, and compared with returning the fly ash to the gasifier 2 for gasification, this method has a higher resource utilization rate.

[0040] As an extension, the dust outlet of the bag filter 6 is connected to the feed inlet of the ball mill 10, which is used to mix fly ash with ceramic raw materials. The discharge outlet of the ball mill 10 is connected to the raw material inlet of the ceramic firing kiln 11.

[0041] As a further extension, the dust outlet of the bag filter dust collector 6 is connected sequentially to the feed inlet of the ball mill 10 via a metering pump 7, an ash hopper 8, and a disc feeder 9. The fly ash is transported to the ash hopper 8 via the metering pump 7, and then to the ball mill 10 via the disc feeder 9. This conveying method offers better conveying efficiency and economy than the combination of a conventional hopper pump and a continuous conveying pump.

[0042] Furthermore, the gas outlet of the bag filter 6 is connected to the burners in the ceramic firing kiln 11 via a pipeline. The bag filter 6 filters the crude coal gas, and by setting the operating parameters in the waste heat recovery mechanism, it can obtain hot coal gas that matches the performance of the burners in the ceramic firing kiln 11. This hot coal gas does not require temperature or pressure regulation and is suitable for direct use as fuel in the ceramic firing kiln 11. Preferably, the hot coal gas has a temperature of 330℃, a pressure of 8.0 kPa·G, and a calorific value ≥1350 kcal / Nm³. 3 .

[0043] In a further preferred embodiment, the material outlet at the bottom of the cyclone separator 3 is connected to the gasifier 2, which is used to return the solid particles separated by the cyclone separator 3 to the gasifier 2, thereby improving the utilization rate of coal.

[0044] More preferably, the feed inlet of the gasifier 2 is connected to the raw coal conveying mechanism 1 for feeding coal into the gasifier 2.

[0045] The specific operation process of this device is as follows: (1) Raw coal enters the gasifier 2 through the raw coal conveying mechanism 1 and is burned to form crude coal gas; (2) The crude coal gas is separated by the cyclone separator 3 and the crude coal gas mixed with fly ash at about 900°C enters the air preheater 4; the solid particles separated by the cyclone separator 3 are returned to the gasifier 2; (3) After being cooled by the air preheater 4, the crude coal gas at about 500~550°C is obtained and then enters the kettle heat exchanger 5; (4) The crude coal gas coming out of the kettle heat exchanger 5 enters the bag filter dust removal mechanism 6 for dust removal; (5) The hot coal gas enters the gas inlet of the ceramic firing kiln 11 through the gas outlet of the bag filter dust removal mechanism 6 and enters the raw material inlet of the ceramic firing kiln 11 through the pipeline; the fly ash enters the raw material inlet of the ceramic firing kiln 11 through the dust outlet of the bag filter dust removal mechanism 6 and enters the raw material inlet of the ceramic firing kiln 11 through the pipeline.

[0046] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A coal gasification system for ceramic production, comprising a gasifier (2), a cyclone separator (3), a waste heat recovery mechanism, and a bag filter (6) connected in sequence, characterized in that, The gasifier (2) has a gas production capacity of ≤10kNm³. 3 The small-capacity gasifier with a capacity of / h includes a waste heat recovery mechanism comprising an air preheater (4) and a kettle heat exchanger (5) connected together. The hot coal gas separated by the cyclone separator (3) is cooled sequentially by the air preheater (4) and the kettle heat exchanger (5). The outlet of the hot coal gas channel in the kettle heat exchanger (5) is connected to the inlet of the bag filter mechanism (6). The gas outlet of the bag filter mechanism (6) is directly connected to the gas inlet of the ceramic firing kiln (11) through a pipeline. A single gasifier (2) is used to supply gas to a single ceramic firing kiln (11).

2. The coal gasification system for ceramic production according to claim 1, characterized in that, The air preheater (4) and the kettle heat exchanger (5) are bidirectionally connected; the outlet end of the cooling medium circuit in the kettle heat exchanger (5) is connected to the inlet end of the cooling medium circuit in the air preheater (4) to provide steam to the air preheater (4); the gasifier (2) is connected to the outlet end of the cooling medium circuit in the air preheater (4) through a pipe to provide gasifying agent to the gasifier (2).

3. The coal gasification system for ceramic production according to claim 1, characterized in that, The dust outlet of the bag filter (6) is connected to the raw material inlet of the ceramic firing kiln (11) via a pipe.

4. The coal gasification system for ceramic production according to any one of claims 1-3, characterized in that, The dust outlet of the bag filter (6) is connected to the feed inlet of the ball mill (10). The ball mill (10) is used to mix fly ash with ceramic raw materials. The discharge outlet of the ball mill (10) is connected to the raw material inlet of the ceramic firing kiln (11).

5. The coal gasification system for ceramic production according to claim 4, characterized in that, The dust outlet of the bag filter (6) is connected to the feed inlet of the ball mill (10) in sequence through a metering pump (7), a dust hopper (8), a disc feeder (9).

6. The coal gasification system for ceramic production according to claim 5, characterized in that, The gas outlet of the bag filter (6) is connected to the burner in the ceramic firing kiln (11) via a pipe.

7. The coal gasification system for ceramic production according to claim 6, characterized in that, The material outlet at the bottom of the cyclone separator (3) is connected to the gasifier (2) to return the solid particles separated by the cyclone separator (3) to the gasifier (2).

8. The coal gasification system for ceramic production according to claim 7, characterized in that, The feed inlet of the gasifier (2) is connected to the raw coal conveying mechanism (1) for feeding coal into the gasifier (2).

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