Deslagging device for coal water slurry gasification coarse slag with low carbon content

Abstract

The utility model belongs to the technical field of coal water slurry gasification, and particularly relates to a deslagging device for coal water slurry gasification coarse slag with low carbon content. Fine slag generated by combustion of the coal water slurry gasification furnace is high in carbon content, and coarse slag is low in carbon content; fine slag is inevitably mixed into coarse slag generated in the prior art, so that the carbon content of the coarse slag is high; through the cyclone separator, slag water discharged by the lock hopper of the coal water slurry gasification device is subjected to cyclone separation to obtain fine slag, and then coarse slag is subjected to dehydration treatment to obtain coarse slag with low carbon content; according to the utility model, the cyclone separator is arranged behind the lock hopper, so that the operation pressure and investment of the cyclone separator can be greatly reduced, and meanwhile, clarified black water generated by a coarse slag pool and a settling tank in the coal water slurry gasification device or ammonia-containing wastewater generated by the coal water slurry gasification device is used for the cyclone separator; compared with a coarse slag pulping and carbon separation technology in the prior art, the method has the advantages that the consumption of fresh water is greatly reduced, and the output of wastewater and the load of a wastewater treatment device are also reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of water-coal slurry gasification, in particular to a slag discharge device with low carbon content of coarse slag from water-coal slurry gasification. Background Art

[0002] As one of the core technologies in the coal chemical industry, water-coal slurry gasification technology converts organic matter in coal into combustible gas through high temperature, high pressure, and catalysts. It offers significant advantages such as high efficiency, environmental protection, and energy conservation. Currently, this technology has become an indispensable clean energy technology for industries such as power, chemical, and metallurgy. my country has reached internationally advanced levels in the development and application of water-coal slurry gasifiers, successfully achieving large-scale industrial production, improving coal resource utilization efficiency and reducing environmental pollution.

[0003] However, the coal-water slurry gasification process produces a large amount of coarse slag. This slag has significant variations in physical properties and a complex chemical composition, depending on factors such as the type of raw coal, gasification conditions, and operating procedures. Its chemical composition primarily consists of inorganic minerals, primarily oxides such as SiO2, Al2O3, CaO, and Fe2O3, along with a small amount of unburned carbonaceous residue. Furthermore, the coarse slag contains a certain amount of moisture and volatile matter, and its particle size ranges from a few millimeters to tens of millimeters, presenting forms such as massive and granular. It has a complex pore structure and a large specific surface area. These factors significantly impact its utilization and treatment.

[0004] Currently, coal chemical companies primarily handle crude slag from water-coal slurry gasification by transporting it themselves or outsourcing it to third parties for storage. This approach not only consumes significant land resources, but also, due to the high moisture content of the slag, is prone to leakage and dust during transportation and storage, causing significant environmental pollution. Furthermore, the unburned carbon resources in the slag are not fully utilized, resulting in a waste of carbon resources. Therefore, strengthening research on slag treatment and disposal technologies to achieve resource utilization and harmless treatment is of great significance.

[0005] To achieve efficient and comprehensive utilization of crude slag, many companies and research institutions are actively developing efficient separation and extraction technologies to achieve efficient separation of inorganic minerals and unburned carbon residues in the crude slag. However, they have not explored how to reduce the carbon content of the crude slag before it is formed. Instead, they have studied the separation of residual carbon and inorganic minerals after the crude slag is formed. This separation technology also requires slurrying the crude slag, which consumes a large amount of water resources. The wastewater generated increases the load on the sewage treatment plant. Therefore, it is particularly necessary to study the direct production of low-carbon slag by water-coal slurry gasification. Utility Model Content

[0006] Based on the existing technical problems, the utility model provides a slag discharge device with low carbon content in coarse slag from water-coal slurry gasification. The utility model makes the coarse slag discharged from the gasification device have low carbon content, broadens the resource utilization path of the coarse slag, and also reduces the consumption of water resources for carbon content in the coarse slag, reduces the amount of wastewater, and reduces the load of the wastewater treatment device.

[0007] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0008] A slag discharge device for coarse slag from water-coal slurry gasification with low carbon content, comprising a gasifier, a lock hopper, a slag-water buffer tank, and a cyclone separator. The bottom of the gasifier is connected to the top of the lock hopper via a slag breaker, the bottom of the lock hopper is connected to the top of the slag-water buffer tank via a pipeline, the bottom of the slag-water buffer tank is connected to the cyclone separator via a pipeline, the coarse slag outlet at the bottom of the cyclone separator is connected to the coarse slag pool via a pipeline, the water inlet of the cyclone separator is connected to the buffer water tank, and the water outlet of the cyclone separator is connected to the sedimentation tank via a pipeline; the clear liquid outlet of the coarse slag pool and the clear liquid outlet of the sedimentation tank are connected to the buffer water tank via a pipeline and a clear liquid water pump, respectively.

[0009] Furthermore, a plurality of cyclone separators are arranged in parallel or in series.

[0010] Furthermore, the lock hopper is provided with a pressure equalizing pipe connected to the quenching chamber of the gasifier; the lock hopper is also provided with a water supply buffer tank, and a pressure relief pipe is provided on the top of the lock hopper to connect to the top of the water supply buffer tank;

[0011] Furthermore, the lock hopper is provided with a slag discharge circulation pump, the inlet of the slag discharge circulation pump is connected to the lock hopper, and the outlet of the slag discharge circulation pump is connected to the quenching chamber of the gasifier;

[0012] Furthermore, the water inlet of the cyclone separator is lower than the water outlet of the cyclone separator;

[0013] Furthermore, the buffer water tank is also connected to the fresh water network and / or the ammonia-containing wastewater pipeline of the coal gasification device through a pipeline;

[0014] A method for removing slag from water-coal slurry gasification coarse slag with low carbon content, comprising the following steps:

[0015] (1) The coal-water slurry burns in the gasifier to produce gasified slag and synthesis gas, which enter the quenching water at the bottom of the gasifier for cooling. The cooled synthesis gas carries a portion of fine slag and flows out from the outlet on the side of the gasifier. The cooled coarse slag and the other portion of fine slag are crushed by the slag crusher at the bottom of the gasifier to obtain coarse slag containing fine slag;

[0016] (2) The coarse slag obtained in step (1) is discharged into the lock hopper. When a certain amount of coarse slag is discharged into the lock hopper, the gasifier stops discharging slag and the lock hopper starts discharging slag into the slag water buffer tank. After the lock hopper finishes discharging slag, the gasifier starts discharging slag into the lock hopper.

[0017] (3) In step (2), the coarse slag and water in the slag water buffer tank enter the cyclone separator, and water is added to the cyclone separator at the same time. Under the action of the cyclone, the fine slag in the coarse slag is gradually separated from the coarse slag, and the coarse slag settles at the bottom of the cyclone separator and is discharged into the coarse slag pool. The separated fine slag is carried out of the cyclone separator by water and enters the sedimentation tank; the coarse slag at the bottom of the coarse slag pool is dehydrated to obtain coarse slag with low carbon content, and the fine slag slurry at the bottom of the sedimentation tank is dehydrated to obtain fine slag; the clarified black water from the sedimentation tank and the coarse slag pool is sent to the cyclone separator to continue circulating the cyclone to separate the fine slag;

[0018] Furthermore, when the lock hopper is in operation, the lock hopper is kept full of water through the water replenishment buffer tank; before the gasifier discharges slag, the lock hopper and the gasifier quenching chamber are pressure-equalized through a pressure-equalizing pipe; after the pressure equalization is completed, the gasifier starts to discharge slag, and the water in the lock hopper is circulated to the gasifier quenching chamber through the slag discharge circulation pump, bringing the slag in the quenching chamber into the lock hopper.

[0019] Furthermore, the cyclone separator is replenished with clarified black water and / or fresh water from the sedimentation tank and / or clarified black water from the coarse slag pool and / or ammonia-containing wastewater.

[0020] Furthermore, the pressure difference between the lock hopper and the quenching chamber of the gasifier after equalization shall not be greater than 0.3 MPa; the lock hopper shall be pressure-relieved through a pressure relief pipe before slag discharge, and the pressure in the lock hopper shall not be greater than 0.5 MPa after pressure relief; Beneficial effects

[0021] 1. Since the fine slag produced by the combustion of the water-coal slurry gasifier has a high carbon content and the coarse slag has a low carbon content, the utility model sets a cyclone separator to perform cyclone separation on the slag-water mixture discharged from the lock bucket of the water-coal slurry gasifier, and at the same time adds water to the cyclone separator to perform cyclone separation on the fine slag in the coarse slag. The water carries the fine slag out of the cyclone separator and enters the sedimentation tank. The fine slag and water are sedimented and separated in the sedimentation tank. The coarse slag at the bottom of the cyclone separator is discharged into the coarse slag pool and then dehydrated to obtain coarse slag with low carbon content.

[0022] 2. The slag-water mixture discharged from the lock bucket of the utility model is separated into fine slag in the cyclone separator to obtain coarse slag with low carbon content, thereby avoiding the consumption of water resources in the coarse slag pulping and carbon separation in the existing technology, and also reducing the amount of wastewater generated by the coarse slag carbon separation, reducing the load of the wastewater treatment device.

[0023] 3. The utility model arranges the cyclone separator after the lock bucket, which can reduce the operating pressure of the cyclone separator, reduce the requirements for equipment, and reduce equipment investment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the structure of the utility model;

[0025] In the figure: 1-gasification furnace; 2-lock hopper; 3-slag water buffer tank; 4-cyclone separator; 5-sedimentation tank; 6-buffer water tank; 7-coarse slag pool; 8-water buffer tank. DETAILED DESCRIPTION

[0026] Example

[0027] Reference Figure 1 Since the fine slag produced by the combustion of the water-coal slurry gasification furnace has a high carbon content and the coarse slag has a low carbon content; the coarse slag produced by the existing technology inevitably mixes with fine slag, resulting in a high carbon content in the coarse slag, making it difficult to utilize the coarse slag as a resource; in addition, the existing technology of coarse slag pulping and carbon separation consumes a lot of water resources, generates a lot of wastewater, and puts a heavy load on the wastewater treatment device. In order to make the carbon content of the coarse slag produced by the existing water-coal slurry gasification technology as low as possible, broaden the resource utilization path of the coarse slag, and at the same time reduce the consumption of water resources, reduce the amount of wastewater, and reduce the load of the wastewater treatment device, the utility model provides a slag discharge device with low carbon content of coarse slag from water-coal slurry gasification, including a gasifier 1, a lock hopper 2, a slag-water buffer tank 3, and a cyclone separator 4. The bottom of the gasifier 1 is connected to the top of the lock hopper 2 through a slag crusher, and the lock hopper 2 is provided with a pressure-equalizing pipe and connected to the quenching chamber of the gasifier 1. Before the gasifier 1 discharges slag, the pressure is equalized by the pressure-equalizing pipe to reduce the pressure difference between the quenching chamber of the gasifier 1 and the lock hopper 2, so as to avoid the operation fluctuation of the gasifier 1 caused by excessive pressure difference during slag discharge; the bottom of the lock hopper 2 is connected to the top of the slag-water buffer tank 3 through a pipe, and the lock hopper 2 is also provided with a water supply buffer tank 8 to provide sufficient water for the lock hopper 2 when it is running. A pressure relief pipe is provided on the top of the lock hopper 2 and is connected to the top of the water supply buffer tank 8. Before the lock hopper 2 discharges slag, the pressure in the lock hopper 2 is reduced to 0.5M through the pressure relief pipe. Pa or less, to avoid the impact of excessive pressure in the lock hopper 2 on the slag water buffer tank 3 during slag discharge; the lock hopper 2 is provided with a slag discharge circulation pump, the inlet of the slag discharge circulation pump is connected to the lock hopper 2, and the outlet of the slag discharge circulation pump is connected to the quenching chamber of the gasifier 1; so that the water in the lock hopper 2 is forced to circulate into the quenching chamber of the gasifier 1, and at the same time, the slag water in the quenching chamber of the gasifier 1 enters the lock hopper 2; the bottom of the slag water buffer tank 3 is connected to the cyclone separator 4 through a pipeline, and the cyclone separator 4 is provided with one; the cyclone separator The coarse slag outlet at the bottom of 4 is connected to the coarse slag pool 7 through a pipeline, the water inlet of the cyclone separator 4 is connected to the buffer water tank 6, and the water outlet of the cyclone separator 4 is connected to the sedimentation tank 5 through a pipeline; the water inlet of the cyclone separator 4 is lower than the water outlet of the cyclone separator 4; the buffer water tank 6 is also connected to the fresh water network and the ammonia-containing wastewater pipeline of the coal gasification device through a pipeline; the clear liquid outlet of the coarse slag pool 7 and the clear liquid outlet of the sedimentation tank 5 are connected to the buffer water tank 6 through a pipeline and a clear liquid water pump respectively.

[0028] A method for removing slag from water-coal slurry gasification coarse slag with low carbon content, comprising the following steps:

[0029] (1) The coal-water slurry is burned in the gasifier 1 to produce gasified slag and synthesis gas, which enter the quenching water at the bottom of the gasifier 1 for cooling. The cooled synthesis gas carries a part of the fine slag and flows out from the outlet on the side of the gasifier 1. The cooled coarse slag and the other part of the fine slag are crushed by the slag crusher at the bottom of the gasifier 1 to obtain coarse slag containing fine slag;

[0030] (2) The coarse slag obtained in step (1) is discharged into the lock hopper 2. When a certain amount of coarse slag is discharged into the lock hopper 2, the gasifier 1 stops discharging slag, and the lock hopper 2 starts discharging slag into the slag water buffer tank 3. After the lock hopper 2 finishes discharging slag, the gasifier 1 starts discharging slag into the lock hopper 2.

[0031] (3) In step (2), the coarse slag and water in the slag water buffer tank 3 enter the cyclone separator 4, and water is added to the cyclone separator 4 at the same time. Under the action of the cyclone, the fine slag in the coarse slag is gradually separated from the coarse slag, and the coarse slag settles at the bottom of the cyclone separator 4 and is discharged to the coarse slag pool 7. The separated fine slag is carried out of the cyclone separator 4 by water and enters the sedimentation tank 5; the coarse slag at the bottom of the coarse slag pool 7 is dehydrated to obtain coarse slag with low carbon content, and the fine slag slurry at the bottom of the sedimentation tank 5 is dehydrated to obtain fine slag; the black water clarified in the sedimentation tank 5 and the coarse slag pool 7 is sent to the cyclone separator 4 to continue circulating the cyclone to separate the fine slag;

[0032] When the lock hopper 2 is in operation, the water supply buffer tank 8 is used to keep the lock hopper 2 full of water; before the gasifier 1 discharges slag, the lock hopper 2 and the quenching chamber of the gasifier 1 are pressure-equalized through the pressure-equalizing pipe; after the pressure equalization is completed, the gasifier 1 starts to discharge slag, and the water in the lock hopper 2 is circulated to the quenching chamber of the gasifier 1 through the slag discharge circulation pump, bringing the slag in the quenching chamber into the lock hopper 2.

[0033] The cyclone separator 4 is replenished with the clarified black water from the sedimentation tank 5 and the clarified black water from the coarse slag pool 7 .

[0034] The pressure difference between the lock hopper 2 and the quenching chamber of the gasifier 1 after equalization shall not be greater than 0.3 MPa; the lock hopper 2 shall be depressurized through a pressure relief pipe before slag discharge, and the pressure in the lock hopper 2 shall not be greater than 0.5 MPa after pressure relief;

[0035] Another embodiment differs from embodiment 1 in that: two cyclone separators 4 are provided, and the two cyclone separators 4 are connected in parallel;

[0036] Another embodiment differs from embodiment 1 in that: two cyclone separators 4 are provided, and three cyclone separators 4 are connected in parallel;

[0037] Another embodiment differs from embodiment 1 in that: two cyclone separators 4 are provided, and the two cyclone separators 4 are connected in series;

[0038] Another embodiment differs from embodiment 1 in that: three cyclone separators 4 are provided, and the three cyclone separators 4 are connected in series;

[0039] Another embodiment is different from the embodiment 1 in that the cyclone separator 4 is replenished with the clarified black water from the sedimentation tank 5 , the clarified black water from the coarse slag pool 7 , and the ammonia-containing wastewater produced by the gasification device.

[0040] Another embodiment differs from embodiment 1 in that the cyclone separator 4 is replenished with the clarified black water and fresh water from the sedimentation tank 5 , the clarified black water from the coarse slag pool 7 , and the ammonia-containing wastewater produced by the gasification device.

[0041] The working principle of the present invention is as follows: since the fine slag produced by the combustion of the water-coal slurry gasification furnace 1 has a high carbon content, and the coarse slag has a low carbon content; and the coarse slag produced by the prior art is inevitably mixed with fine slag, resulting in a high carbon content in the coarse slag; the present invention utilizes a cyclone separator 4 to cyclone the slag-water mixture discharged from the lock bucket 2 of the water-coal slurry gasification device to separate the fine slag, and then dehydrates the coarse slag to obtain coarse slag with low carbon content; in addition, the present invention arranges the cyclone separator 4 behind the lock bucket 2 of the water-coal slurry gasification device, which can greatly reduce the operating pressure and investment of the cyclone separator 4, and at the same time, the clarified black water produced by the coarse slag pool 7 and the sedimentation tank 5 in the water-coal slurry gasification device or the ammonia-containing wastewater produced by the water-coal slurry gasification device is used for the cyclone separator 4. Compared with the coarse slag pulping and carbon separation technology in the prior art, the consumption of fresh water is greatly reduced, and the amount of wastewater generated and the load of the wastewater treatment device are also reduced.

[0042] Modifications and changes to the invention made by those familiar with the present invention are all within the patent scope of the present invention, and are not limited to those described in the embodiments.

Claims

1. A slag discharge device for low carbon content coarse slag from water-coal slurry gasification, characterized by: It includes a gasifier, a lock hopper, a slag water buffer tank, and a cyclone separator. The bottom of the gasifier is connected to the top of the lock hopper through a slag breaker, the bottom of the lock hopper is connected to the top of the slag water buffer tank through a pipeline, the bottom of the slag water buffer tank is connected to the cyclone separator through a pipeline, the coarse slag outlet at the bottom of the cyclone separator is connected to the coarse slag pool through a pipeline, the water inlet of the cyclone separator is connected to the buffer water tank, and the water outlet of the cyclone separator is connected to the sedimentation tank through a pipeline; the clear liquid outlet of the coarse slag pool and the clear liquid outlet of the sedimentation tank are connected to the buffer water tank through a pipeline and a clear liquid water pump respectively.

2. The slag discharge device for low carbon content coarse slag from water-coal slurry gasification according to claim 1, characterized in that: The cyclone separators are arranged in multiple units in parallel or in series.

3. The slag discharge device for low carbon content coarse slag from water-coal slurry gasification according to claim 1, characterized in that: The lock hopper is provided with a pressure equalizing pipe connected to the quenching chamber of the gasifier; the lock hopper is also provided with a water replenishment buffer tank, and a pressure relief pipe is provided on the top of the lock hopper to connect to the top of the water replenishment buffer tank.

4. The slag discharge device for low carbon content coarse slag from water-coal slurry gasification according to claim 1, characterized in that: The lock hopper is provided with a slag discharge circulation pump, the inlet of the slag discharge circulation pump is connected to the lock hopper, and the outlet of the slag discharge circulation pump is connected to the quenching chamber of the gasifier.

5. The slag discharge device for low carbon content coarse slag from water-coal slurry gasification according to claim 1, characterized in that: The water inlet of the cyclone separator is lower than the water outlet of the cyclone separator.

6. The slag discharge device for low carbon content coarse slag from water-coal slurry gasification according to claim 1, characterized in that: The buffer water tank is also connected to the fresh water network and / or the ammonia-containing wastewater pipeline of the coal gasification device through a pipeline.

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