Large-scale treatment system for gasified fine slag

Abstract

The utility model provides a large-scale treatment system for gasified fine slag, and belongs to the technical field of coal chemical industry. The problems that gasification fine slag is difficult to ignite and burn out and the stable combustion capacity is weak when the gasification fine slag is treated in a combustion mode are solved. In the large-scale gasification fine slag treatment system, an inlet of a gas-solid separation device is communicated with a discharge port of a roller dryer, a solid outlet of the gas-solid separation device is communicated with a gasification dry slag inlet of a feeding device, and a biomass fuel bin is communicated with a biomass fuel inlet of the feeding device; the feeding device can mix gasified dry slag and biomass fuel according to a set proportion, a discharging port of the feeding device is communicated with the circulating fluidized bed hearth, a gas outlet of the circulating fluidized bed hearth is communicated with the chimney, and a gas outlet of the gas-solid separation device is communicated with the chimney. Through the mode that the gasified dry slag and the biomass fuel are mixed and then combusted, the burnout level of the gasified fine slag can be effectively improved, the difficult-to-burn problem is solved, and clean combustion treatment is achieved.

Description

Technical Field

[0001] The utility model belongs to the field of coal chemical industry, and particularly relates to a large-scale disposal system for gasified fine slag. Background Art

[0002] On March 18, 2021, the National Development and Reform Commission, the Ministry of Science and Technology and ten other ministries and commissions jointly issued the "Guiding Opinions on the Comprehensive Utilization of Bulk Solid Waste in the 14th Five-Year Plan". The opinions pointed out that for the treatment of coal gangue and fly ash, the comprehensive utilization level of coal gangue and fly ash should be continuously improved. According to statistics, the million-ton coal chemical process will produce about 900,000 tons of ash slag each year, mainly from coal gasification slag. Coal gasification slag includes coarse slag and fine slag. The coarse slag has a low carbon content, generally around 10%; the fine slag has a high residual carbon content, generally up to 30% or more, and the amount produced accounts for about 20% of the gasification slag discharge. The gasification coarse slag has a large particle size and can be discharged directly from the bottom of the furnace. Due to its low carbon content and similar composition to boiler ash, it can be processed and utilized by mixing it into road building materials and raw materials for cement production, or it can be backfilled, so the treatment of coarse slag is relatively simple. However, due to the high loss on ignition of gasified fine slag and its inability to meet the requirements of building blending raw materials, gasified fine slag is currently mainly treated by landfill, which has a poor volume reduction effect and causes a great waste of energy. At the same time, gasified fine slag contains a large amount of water, and simple landfill treatment will also lead to a waste of water resources. In the landfill process, due to the non-standard or imperfect measures such as anti-seepage and anti-scattering, secondary pollution is easily caused. If you want to treat gasified fine slag by combustion, there are the following problems: due to the high degree of graphitization of gasified fine slag, the activation energy is significantly higher than that of coal powder, which makes it difficult to ignite and burn out; due to the low volatile matter and large ash content of gasified fine slag, the conventional combustion method has problems such as weak stable combustion ability and low cross-sectional heat load; due to the small particle size of gasified fine slag, the combustion temperature is low (below 1000℃) when using fluidized bed treatment, and the gasified fine slag stays in the furnace for a short time, which leads to the problem of difficulty in burning out. Utility Model Content

[0003] In view of this, in order to solve the problems of difficulty in ignition and burnout of gasified fine slag and weak stable combustion ability when treating gasified fine slag by combustion, the utility model proposes a large-scale treatment system for gasified fine slag.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] A large-scale treatment system for gasification fine slag, comprising:

[0006] A drum dryer having a gasified wet slag inlet;

[0007] A gas-solid separation device, the inlet of which is connected to the discharge port of the drum dryer;

[0008] A biomass fuel bin and a feeding device, wherein the solid outlet of the gas-solid separation device is connected to the gasified dry slag inlet of the feeding device, the biomass fuel bin is connected to the biomass fuel inlet of the feeding device, and the feeding device can mix the gasified dry slag and the biomass fuel according to a set ratio;

[0009] A circulating fluidized bed boiler has a circulating fluidized bed furnace, and the discharge port of the feeding device is connected to the circulating fluidized bed furnace;

[0010] A chimney, wherein the gas outlet of the circulating fluidized bed furnace is connected to the chimney, and the gas outlet of the gas-solid separation device is connected to the chimney.

[0011] As a preferred solution of the above-mentioned large-scale disposal system for gasified fine slag, the ratio of the depth to the diameter of the circulating fluidized bed furnace is greater than 2.

[0012] As a preferred solution of the above-mentioned large-scale disposal system for gasification fine slag, the large-scale disposal system for gasification fine slag also includes a cyclone separator, the inlet of the cyclone separator is connected to the air outlet of the circulating fluidized bed furnace, the gas outlet of the cyclone separator is connected to the chimney, and the solid outlet of the cyclone separator is connected to the circulating fluidized bed furnace.

[0013] As a preferred solution of the above-mentioned large-scale disposal system for gasified fine slag, the large-scale disposal system for gasified fine slag also includes a first fan, the inlet of the first fan is connected to the gas outlet of the cyclone separator, the outlet of the first fan is connected to the drum dryer, and the first fan is used to recycle the flue gas after combustion as a heat source for the drum dryer.

[0014] As a preferred solution of the above-mentioned large-scale treatment system for gasified fine slag, the large-scale treatment system for gasified fine slag further includes a dust removal device, the inlet of the dust removal device is connected to the gas outlet of the cyclone separator, and the outlet of the dust removal device is connected to the chimney.

[0015] As a preferred solution of the above-mentioned large-scale treatment system for gasified fine slag, the large-scale treatment system for gasified fine slag further includes a condenser, the inlet of the condenser is connected to the gas outlet of the gas-solid separation device, and the outlet of the condenser is connected to the chimney.

[0016] As a preferred solution of the above-mentioned large-scale treatment system for gasified fine slag, the large-scale treatment system for gasified fine slag further includes a second fan, the inlet of the second fan is connected to the outlet of the condenser, and the outlet of the second fan is connected to the chimney.

[0017] As a preferred solution of the above-mentioned large-scale treatment system for gasification fine slag, the large-scale treatment system for gasification fine slag further includes a heat exchanger assembly, and the heat exchanger assembly is arranged in the flue gas channel of the circulating fluidized bed boiler.

[0018] As a preferred solution of the above-mentioned large-scale disposal system of gasified fine slag, the heat exchanger assembly includes a high-temperature heat exchanger and a low-temperature heat exchanger, and the high-temperature heat exchanger and the low-temperature heat exchanger are both arranged on the flue gas channel of the circulating fluidized bed boiler.

[0019] As a preferred solution of the above-mentioned large-scale treatment system for gasified fine slag, the large-scale treatment system for gasified fine slag also includes a steam turbine, which is connected to the high-temperature heat exchanger, and the high-temperature steam generated by the high-temperature heat exchanger is used for the steam turbine to generate power.

[0020] Compared with the prior art, the utility model provides a large-scale treatment system for gasification fine slag with the following beneficial effects:

[0021] 1. The utility model provides a large-scale disposal system for gasified fine slag. The feeding device mixes the gasified dry slag and the biomass fuel according to a set ratio and sends them into the circulating fluidized bed furnace for combustion. Since the ignition point of the biomass fuel is low and the ignition is rapid, the gasified dry slag can be fully preheated, and the gasified dry slag is easier to burn after being mixed with the biomass fuel. The method of mixing the gasified dry slag with the biomass fuel and then burning it can effectively improve the burnout level of the gasified fine slag, solve the problem of difficult combustion, and achieve clean combustion disposal.

[0022] 2. The utility model provides a large-scale disposal system for gasified fine slag, which adopts a circulating fluidized bed boiler with a slender furnace body, that is, a circulating fluidized bed boiler with a ratio of depth to diameter of the circulating fluidized bed furnace greater than 2. It can increase the residence time of the mixed fuel after the biomass fuel and the gasified dry slag are mixed in the furnace, making it burn more completely, which helps to solve the problem of the difficulty in burning gasified fine slag.

[0023] 3. The utility model provides a large-scale treatment system for gasified fine slag, which is provided with a first fan, the inlet of the first fan is connected to the gas outlet of the cyclone separator, and the outlet of the first fan is connected to the drum dryer. The first fan is used to circulate the flue gas after combustion as a heat source for the drum dryer. The first fan transports the high-temperature flue gas after combustion back to the drum dryer, and the high-temperature flue gas provides a heat source for the drum dryer, realizing resource recycling. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the accompanying drawings:

[0025] Figure 1It is a structural schematic diagram of a large-scale treatment system for gasified fine slag provided by a specific embodiment of the utility model.

[0026] In the figure:

[0027] 1. Drum dryer; 2. Gas-solid separation device; 3. Condenser; 4. Biomass fuel bin; 5. Feeding device; 6. Circulating fluidized bed furnace; 7. Chimney; 8. Cyclone separator; 9. Dust removal device; 10. First fan; 11. Second fan; 101. Gasification fine slag inlet. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely explain the technical solutions in the embodiments of the utility model. It should be noted that the embodiments and features in the embodiments of the utility model can be combined with each other without conflict, and the described embodiments are only part of the embodiments of the utility model, not all of the embodiments.

[0029] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0031] In the description of this embodiment, the terms "upper", "lower", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0032] See also Figure 1 To describe this embodiment, the utility model provides a large-scale disposal system for gasified fine slag, which includes a drum dryer 1, a gas-solid separation device 2, a biomass fuel bin 4, a feeding device 5, a circulating fluidized bed furnace 6 and a chimney 7. The drum dryer 1 has a gasification wet slag inlet 101, the inlet of the gas-solid separation device 2 is connected to the discharge port of the drum dryer 1, the solid outlet of the gas-solid separation device 2 is connected to the gasification dry slag inlet of the feeding device 5, the biomass fuel bin 4 is connected to the biomass fuel inlet of the feeding device 5, the feeding device 5 can mix the gasification dry slag and the biomass fuel according to a set ratio, the discharge port of the feeding device 5 is connected to the circulating fluidized bed furnace 6, the air outlet of the circulating fluidized bed furnace 6 is connected to the chimney 7, and the gas outlet of the gas-solid separation device 2 is connected to the chimney 7.

[0033] In the large-scale disposal system of gasified fine slag, the gasified fine slag enters the drum dryer 1 from the gasified fine slag inlet 101 for drying. The drum dryer 1 can fully dry the gasified fine slag and dry the water content of the gasified fine slag to less than 10%. The dried gasified fine slag enters the gas-solid separation device 2 from the drum dryer 1. The gas-solid separation device 2 separates the solid and gas in the dried gasified fine slag, and the gas is discharged from the chimney 7. The solid is gasified dry slag. The gasified dry slag and the biomass fuel are mixed in the feeding device 5. The feeding device 5 mixes the gasified dry slag and the biomass fuel according to the set ratio and then sends them into the circulating fluidized bed furnace 6 for combustion. Since the ignition point of the biomass fuel is low and the ignition is rapid, the gasified dry slag can be fully preheated, and the gasified dry slag is easier to burn after being mixed with the biomass fuel. The method of mixing the gasified dry slag with the biomass fuel and then burning it can effectively improve the burnout level of the gasified fine slag, solve the problem of difficult combustion, and achieve clean combustion disposal. In this embodiment, the calorific value ratio of the biomass fuel to the gasified dry residue is 7:3, which can effectively reduce the ignition point and enhance combustion.

[0034] Optionally, the ratio of the depth to the diameter of the circulating fluidized bed furnace 6 is greater than 2. Circulating fluidized bed boilers have the advantages of wide fuel adaptability, high combustion efficiency and low pollutant emissions. In this embodiment, a circulating fluidized bed boiler with a slender furnace body is used, that is, a circulating fluidized bed boiler with a ratio of the depth to the diameter of the circulating fluidized bed furnace 6 greater than 2, which can increase the residence time of the mixed fuel after the biomass fuel and the gasified dry slag are mixed in the furnace, so that it burns more fully, which helps to solve the problem of the difficulty in burning gasified fine slag.

[0035] Optionally, the large-scale disposal system for gasified fine slag further includes a cyclone separator 8, the inlet of the cyclone separator 8 is connected to the gas outlet of the circulating fluidized bed furnace 6, the gas outlet of the cyclone separator 8 is connected to the chimney 7, and the solid outlet of the cyclone separator 8 is connected to the circulating fluidized bed furnace 6. The mixture produced after combustion is separated in the cyclone separator 8, and the gasified dry slag that is not fully burned returns to the circulating fluidized bed furnace 6 to continue burning, which can further help the gasified fine slag to burn out.

[0036] Optionally, the large-scale treatment system for gasified fine slag further includes a first fan 10, the inlet of the first fan 10 is connected to the gas outlet of the cyclone separator 8, the outlet of the first fan 10 is connected to the drum dryer 1, and the first fan 10 is used to recycle the flue gas after combustion as a heat source for the drum dryer 1. The first fan 10 transports the high-temperature flue gas after combustion back to the drum dryer 1, and the high-temperature flue gas provides a heat source for the drum dryer 1, thereby realizing resource recycling.

[0037] Optionally, the large-scale disposal system for gasified fine slag further includes a dust removal device 9, the inlet of the dust removal device 9 is connected to the gas outlet of the cyclone separator 8, and the outlet of the dust removal device 9 is connected to the chimney 7. The gas filtered by the dust removal device 9 is discharged from the chimney 7 to prevent the chimney 7 from being blocked.

[0038] Optionally, the large-scale treatment system for gasified fine slag further includes a condenser 3, the inlet of the condenser 3 is connected to the gas outlet of the gas-solid separation device 2, and the outlet of the condenser 3 is connected to the chimney 7. The condenser 3 can condense and discharge the water vapor in the gas discharged from the gas-solid separation device 2, thereby reducing the water content in the gas.

[0039] Optionally, the large-scale treatment system for gasified fine slag further comprises a second fan 11, the inlet of the second fan 11 is connected to the outlet of the condenser 3, and the outlet of the second fan 11 is connected to the chimney 7. The second fan 11 can help the gas passing through the condenser 3 to be discharged from the chimney 7.

[0040] Optionally, the large-scale disposal system for gasified fine slag also includes a heat exchanger assembly, which is arranged in the flue gas channel of the circulating fluidized bed boiler. Specifically, the heat exchanger assembly includes a high-temperature heat exchanger and a low-temperature heat exchanger, and the high-temperature heat exchanger and the low-temperature heat exchanger are both arranged on the flue gas channel of the circulating fluidized bed boiler. The high-temperature heat exchanger and the low-temperature heat exchanger are both arranged separately above the flue gas channel, used for heat exchange with the high-temperature flue gas, absorbing the heat of the high-temperature flue gas, reducing the exhaust temperature of the flue gas, saving energy, and improving efficiency. Its function is similar to that of an economizer.

[0041] Optionally, the large-scale treatment system for gasified fine slag further includes a steam turbine, which is connected to a high-temperature heat exchanger, and the high-temperature steam generated by the high-temperature heat exchanger is used for the steam turbine to generate power. The steam turbine is a steam utilization device generated by the boiler, and the high-temperature heat exchanger is a superheater, which heats the feed water to generate high-temperature steam. The high-temperature steam generated by the high-temperature heat exchanger is used for the steam turbine to generate power.

[0042] When the large-scale treatment system for gasified fine slag is working, the gasified fine slag enters the drum dryer 1 from the gasified fine slag inlet for drying. The drum dryer 1 can fully dry the gasified fine slag. The dried gasified fine slag enters the gas-solid separation device 2 from the drum dryer 1. The gas-solid separation device 2 separates the solid and gas in the dried gasified fine slag. The gas enters the condenser 3 and is then discharged from the chimney 7 through the second fan 11. The solid is the gasified dry slag. The gasified dry slag and the biomass fuel are mixed in the feeding device 5, and the mixed fuel is sent to the circulating fluidized bed furnace 6 for combustion. The mixture produced after combustion is separated in the cyclone separator 8, and the gasified dry slag that is not fully burned returns to the circulating fluidized bed furnace 6 to continue burning. A part of the high-temperature flue gas passing through the cyclone separator 8 is transported back to the drum dryer 1 through the first fan 11 to provide a heat source for the drum dryer 1, and the other part is discharged from the chimney 7 after dust removal by the dust removal device 9.

[0043] Obviously, the embodiments of the utility model disclosed above are only used to help illustrate the utility model. The embodiments do not describe all the details in detail, nor do they limit the utility model to only specific implementation methods. According to the content of this specification, many modifications and changes can be made. This specification selects and describes these embodiments in detail in order to better explain the principles and practical applications of the utility model, so that technicians in the relevant technical field can understand and use the utility model well. It is not necessary and impossible to list all the implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the utility model should be included in the scope of protection of the claims of the utility model.

Claims

1. A large-scale treatment system for gasification fine slag, characterized in that: include: A drum dryer (1), wherein the drum dryer (1) has a gasified wet slag inlet (101); A gas-solid separation device (2), wherein the inlet of the gas-solid separation device (2) is connected to the discharge port of the drum dryer (1); A biomass fuel bin (4) and a feeding device (5), wherein the solid outlet of the gas-solid separation device (2) is connected to the gasified dry residue inlet of the feeding device (5), and the biomass fuel bin (4) is connected to the biomass fuel inlet of the feeding device (5), and the feeding device (5) can mix the gasified dry residue and the biomass fuel according to a set ratio; A circulating fluidized bed boiler comprises a circulating fluidized bed furnace (6), wherein the discharge port of the feeding device (5) is connected to the circulating fluidized bed furnace (6); A chimney (7), wherein the gas outlet of the circulating fluidized bed furnace (6) is in communication with the chimney (7), and the gas outlet of the gas-solid separation device (2) is in communication with the chimney (7).

2. The large-scale treatment system for gasification fine slag according to claim 1 is characterized in that: The ratio of the depth to the diameter of the circulating fluidized bed furnace (6) is greater than 2.

3. The large-scale treatment system for gasification fine slag according to claim 1 is characterized in that: It also includes a cyclone separator (8), the inlet of the cyclone separator (8) is connected to the gas outlet of the circulating fluidized bed furnace (6), the gas outlet of the cyclone separator (8) is connected to the chimney (7), and the solid outlet of the cyclone separator (8) is connected to the circulating fluidized bed furnace (6).

4. The large-scale treatment system for gasification fine slag according to claim 3 is characterized in that: It also comprises a first fan (10), the inlet of the first fan (10) is connected to the gas outlet of the cyclone separator (8), the outlet of the first fan (10) is connected to the drum dryer (1), and the first fan (10) is used to circulate the flue gas after combustion as a heat source for the drum dryer (1).

5. The large-scale treatment system for gasification fine slag according to claim 4 is characterized in that: It also comprises a dust removal device (9), the inlet of the dust removal device (9) is connected to the gas outlet of the cyclone separator (8), and the outlet of the dust removal device (9) is connected to the chimney (7).

6. The large-scale treatment system for gasification fine slag according to claim 1 is characterized in that: It also comprises a condenser (3), the inlet of the condenser (3) being connected to the gas outlet of the gas-solid separation device (2), and the outlet of the condenser (3) being connected to the chimney (7).

7. The large-scale treatment system for gasification fine slag according to claim 6 is characterized in that: It also comprises a second fan (11), the inlet of the second fan (11) is connected to the outlet of the condenser (3), and the outlet of the second fan (11) is connected to the chimney (7).

8. The large-scale treatment system for gasification fine slag according to claim 1 is characterized by: It also includes a heat exchanger assembly, which is arranged in the flue gas channel of the circulating fluidized bed boiler.

9. The large-scale treatment system for gasification fine slag according to claim 8, characterized in that: The heat exchanger assembly comprises a high-temperature heat exchanger and a low-temperature heat exchanger, and the high-temperature heat exchanger and the low-temperature heat exchanger are both arranged on the flue gas channel of the circulating fluidized bed boiler.

10. The large-scale treatment system for gasification fine slag according to claim 9, characterized in that: It also includes a steam turbine, which is connected to the high-temperature heat exchanger. The high-temperature steam generated by the high-temperature heat exchanger is used for the steam turbine to generate power.

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