CN216203470U

CN216203470U - Indirect heat exchange type gasification fine slag resource utilization system

Info

Publication number: CN216203470U
Application number: CN202122559790.5U
Authority: CN
Inventors: 白勇; 朱晨军; 汪鎏; 张爱美
Original assignee: Keda Clean Energy Co Ltd
Current assignee: Keda Clean Energy Co Ltd
Priority date: 2021-10-22
Filing date: 2021-10-22
Publication date: 2022-04-05
Anticipated expiration: 2031-10-22

Abstract

The utility model relates to the field of coal chemical industry, in particular to an indirect heat exchange type gasification fine slag resource utilization system. The system comprises: the device comprises a fine slag conveying system, a fine slag drying system, a dry slag storage and washing unit, a fine slag combustion system, an air preheating system and a flue gas treatment system. The system can realize the combustion of the fine slag with low heat value under the condition of no auxiliary combustion of an external heat source, one part of generated heat is used for drying the fine slag, the redundant heat can be used for utilizing waste heat (such as steam generation), the fly ash with volcanic ash-like property is obtained after the fine slag is combusted and decarburized, and the fly ash is an excellent building material raw material. The system realizes the decarbonization and resource utilization of the gasified fine slag, can treat solid waste fine slag, and plays a positive role in carbon emission reduction and carbon neutralization.

Description

Indirect heat exchange type gasification fine slag resource utilization system

Technical Field

The utility model relates to the field of coal chemical industry, in particular to an indirect heat exchange type gasification fine slag resource utilization system.

Background

The gasification fine slag refers to ash slag collected by a slag washing pool after coal reacts in a coal water slurry furnace or an entrained flow bed gasification furnace in the coal chemical production process, and belongs to industrial waste. With the rapid development of the coal chemical industry in China, the output of gasified fine slag is increased year by year, and the discharge amount of the gasified fine slag is about 6000 million tons to 1 hundred million tons every year. The content of dry-based combustible materials of the gasification fine slag is 18-65%, while the carbon content of the gasification fine slag after drying and dehydration is mostly between 15-40%, and the residual heat value is about 1200-3500 kcal/kg. Therefore, the way of handling the gasified fine slag is of great importance. At present, gasification fine slag is treated mainly in a full filling treatment mode, waste of land resources, water resources and residual heat energy is caused, and environmental pollution is caused. The problem of how to treat the gasified fine slag to improve the energy utilization rate, reduce the environmental pollution and the like is an urgent task currently faced by the coal chemical industry.

Through retrieval, the utility model patent application with the patent name of 'treatment system and method for gasified fine slag' has the application number of CN 113028418A and the published date of 2021, 6 and 25, and discloses a treatment system and a method for mixed-burning gasified fine slag of a circulating fluidized bed boiler in the technical field of coal chemical industry, and the main equipment is as follows: a feeding and drying device and a circulating fluidized bed boiler device. The system utilizes equipment such as a slurry pump, a belt conveyor, a circulating fluidized bed boiler and the like to squeeze and dewater the gasified fine slag, heats the squeezed gasified fine slag through a low-grade heat source until water boils to obtain a gasified fine slag filter cake, and then crushes the gasified fine slag filter cake. The utility model solves the problems of high difficulty in solid waste treatment and serious environmental pollution of the gasified fine slag by carrying out drying and mixed combustion treatment on the gasified fine slag, but has more complicated treatment process and more equipment devices, and adopts the procedures of dehydrating and mixed combustion treatment on the gasified fine slag by means of external energy, namely a low-grade heat source, dehydrating and drying the gasified fine slag to obtain a gasified fine slag filter cake, crushing and the like, thereby causing energy consumption in another form.

SUMMERY OF THE UTILITY MODEL

1. Technical problem to be solved by patent

The utility model provides a system for recycling gasified fine slag in an indirect heat exchange manner, which can realize low-calorific-value fine slag combustion without using external heat source for co-combustion in a normal operation stage, introduces an air preheating system to collect and recycle heat generated by drying (adopting an indirect heat exchange manner), combustion and vaporization, and obtains fly ash with volcanic ash-like property after fine slag combustion and decarburization, and the fly ash can be recycled as an excellent building material raw material. The method is more energy-saving, environment-friendly, synergistic and simplified in treating the gasified fine slag, and solves the industry bottleneck problems of high difficulty in treating the gasified fine slag, serious environmental pollution and energy waste.

2. Technical scheme

The purpose of the utility model is realized by the following technical scheme:

an indirect heat exchange type gasification fine slag resource utilization system comprises a fine slag conveying system, a fine slag drying system, a dry slag storage unit, a fine slag combustion system, an air preheating system and a flue gas treatment system; the fine slag conveying system is arranged at the foremost end of the system, and the output end of the fine slag conveying system is connected with one input end of the fine slag drying system; the fine slag drying system, the dry slag storage unit, the fine slag combustion system and the air preheating system are sequentially connected; the output end of the air preheating system is connected with the other input end of the fine slag drying system; the flue gas treatment system is arranged at the tail end of the system, and the output end of the fine slag drying system is connected with the input end of the flue gas treatment system.

A wet fine slag conveying channel is arranged between the fine slag conveying system and the fine slag drying system. An ash-containing flue gas conveying channel is arranged between the fine slag drying system and the air preheating system, and the dried dry fine slag is conveyed to the dry slag storage unit and is used for conveying ash-containing flue gas obtained after the air preheating system conveys the dry fine slag to the fine slag drying system for drying to the flue gas treatment system.

The dry slag storage unit is provided with a quantitative feeding device, and the dry fine slag and hot air obtained by preheating of the air preheating system are mixed and then are jointly conveyed to the fine slag combustion system as primary air of the fine slag combustion system. The fine slag combustion system comprises a combustion furnace, wherein an adiabatic combustion section and a steam generation section are arranged in the combustion furnace, and the adiabatic combustion section is used for rapidly decarbonizing and combusting dry fine slag and hot air; the steam generation section is used for reacting the high-temperature flue gas with water to obtain product steam and controlling the temperature of ash-containing flue gas in the output end of the fine slag combustion system.

The air preheating system is used for mixing ash-containing flue gas which is conveyed by the fine slag combustion system and is formed by decarburization combustion and is mixed with hot flue gas with air, the hot air is obtained after indirect preheating, and the air preheating system is used for conveying the ash-containing flue gas which is mixed with the air and is cooled to the fine slag drying system.

The flue gas treatment system is provided with a discharge end for discharging the ash-containing flue gas after dedusting.

Further, a dust remover is arranged in the flue gas treatment system and used for carrying out solid-gas separation on the dust-containing flue gas: collecting the solid part as fly ash by a dust remover; the flue gas after dust removal is discharged to the atmosphere, and the environmental pollution caused by the emission of waste gas slag is reduced.

3. Advantageous effects

Compared with the prior art, the technical scheme provided by the utility model has the following beneficial effects:

the system can realize independent combustion of gasified fine slag without the consumption of external energy, the heat generated by the system is utilized to support the drying raw material, and meanwhile, the surplus heat can be used as surplus heat (such as steam generation). The system can preheat the air by a preheating system in an indirect heat exchange mode through flue gas, and dry fine slag in the fine slag storage unit is preheated by part of preheated air and then is input into a fine slag combustion system; part of preheated air enters the fine slag combustion system to participate in combustion and enters the fine slag drying system in the form of ash-containing flue gas, so that the multiple recycling of energy is realized.

In addition, the ash-containing flue gas treated by the system can be separated by solid and gas, and the solid part can be collected by a dust remover as fly ash and can be used as an excellent building material raw material; the flue gas after dust removal is discharged to the atmosphere, and the environmental pollution caused by the emission of waste gas slag is reduced.

To sum up, this system utilizes self device design advantage, has realized that the thin sediment of gasification independently burns and utilizes the thin sediment of humidifying dry, the waste heat energy source recycling that the burning produced, adopts measures such as indirect heat transfer, preheated air circulation, self system waste heat circulation, more energy-conserving, environmental protection, the thin sediment of processing gasification with increasing efficiency reach the dry decarbonization utilization's of thin sediment purpose, solved the thin sediment of gasification and handled the big degree of difficulty, environmental pollution is serious, the extravagant industry bottleneck problem of energy.

Drawings

FIG. 1 is a schematic diagram of a system for resource utilization of fine gasification slag by indirect heat exchange;

the reference numerals in the schematic drawings illustrate: 1. a fine slag delivery system; 2. a fine slag drying system; 3. a dry slag storage unit; 4. a fine slag combustion system; 5. an air preheating system; 6. flue gas processing system.

Detailed Description

For a further understanding of the utility model, reference should be made to the following detailed description taken in conjunction with the accompanying drawings and examples.

Example 1

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the scope of protection of the present patent.

Fig. 1 is a flowchart of an indirect heat exchange type gasification fine slag resource utilization system provided by the implementation of the present invention, and the process includes 6 subsystem units: the system comprises a fine slag conveying system 1, a fine slag drying system 2, a dry slag storage unit 3, a fine slag combustion system 4, an air preheating system 5 and a flue gas treatment system 6.

As shown in fig. 1, the fine slag conveying system 1 is arranged at the foremost end of the system, and the output end of the fine slag conveying system 1 is connected with one input end of the fine slag drying system 2; the fine slag drying system 2, the dry slag storage unit 3, the fine slag combustion system 4 and the air preheating system 5 are sequentially connected to form a closed circulating structure. The output end of the air preheating system 5 is connected with the other input end of the fine slag drying system 2; the flue gas treatment system 6 is arranged at the tail end of the system, and the output end of the fine slag drying system 2 is connected with the input end of the flue gas treatment system 6.

The wet gasified fine slag with the water content of 20-50% is conveyed to the fine slag drying system 2 through various levels of fine slag conveying equipment in the fine slag conveying system 1, and the wet gasified fine slag is dried from the water content of 20-50% to the water content of 1-7% in the fine slag conveying system 2 in an indirect heat exchange mode with ash-containing hot flue gas.

As shown in figure 1, the dry gasified fine slag dried in the fine slag conveying system 2 is conveyed to a dry slag storage unit 3 by dry slag conveying equipment, the dry slag storage unit 3 comprises 4-8 sets of quantitative feeding devices, the quantitative feeding devices mix the dry fine slag with hot air 1 preheated by an air preheating system 5 through 4-8 sets of quantitative feeding devices and then the mixed air is used as primary air of a fine slag combustion system 4 to enter the fine slag combustion system 4 together, the mixed temperature of the hot air and the hot fine slag before entering the fine slag combustion system 4 is about 200-750 ℃, and the mixed air and the hot fine slag enter a combustion furnace of the fine slag combustion system 4 to rapidly carry out combustion reaction to release heat.

As shown in figure 1, the main equipment of the fine slag combustion system 4 is a combustion furnace, an adiabatic combustion section and a steam generation section are arranged in the combustion furnace, the adiabatic combustion section is favorable for quick decarburization combustion of dry fine slag and hot air, high-temperature flue gas in the steam generation section reacts with water to generate product steam, and meanwhile, the temperature of ash-containing flue gas at the outlet of the fine slag combustion system 4 is controlled to be generally 750-1050 ℃. The dry fine slag is decarbonized and combusted to form fly ash and hot flue gas, the fly ash and the hot flue gas leave the fine slag combustion system 4 in the form of ash-containing flue gas, and the fly ash and the hot flue gas enter an air preheating system 5.

As shown in figure 1, after ash-containing flue gas at 750-1050 ℃ enters an air preheating system 5, air 1 and air N are preheated, wherein the air 1 is preheated into hot air 1 to preheat dry fine slag from a dry slag storage unit 3, and the hot air and the dry fine slag are jointly sent to a combustion furnace of a fine slag combustion system 4 in the form of primary air. The air N is preheated into N paths of hot air N which is directly sent into a combustion furnace of the fine slag combustion system 4 to participate in combustion reaction. Partial heat generated by burning the fine slag is brought into the fine slag combustion system 4 to participate in combustion reaction in an N + 1-path multi-stage air distribution mode, so that the atmosphere favorable for combustion is improved. Wherein, the ash-containing smoke preheats the air of the N +1 paths by adopting an indirect heat exchange mode. And the ash-containing flue gas at 750-1050 ℃ is cooled by air and then enters the fine slag drying system 2, and the temperature of the ash-containing flue gas after being discharged from the air preheating system 5 is about 250-700 ℃.

As shown in fig. 1, the ash-containing flue gas discharged from the air preheating system enters a fine slag drying system 2 and then dries the wet fine slag conveyed from the fine slag conveying system 1, wherein the drying mode is indirect drying. The moisture content of the fine slag is dried to 1% -7%, and meanwhile, the temperature of the dust-containing flue gas is reduced to 120-220 ℃ and then the dust-containing flue gas enters a flue gas treatment system 6.

As shown in fig. 1, the flue gas treatment system 6 comprises a dust remover, which can perform gas-solid separation on the flue gas containing dust, and the solid part, namely the fly ash, is collected by the dust remover and can be sold as a building material raw material; the flue gas after dust removal is directly discharged to the atmosphere, so that the environmental pollution caused by the discharge of waste gas and slag is reduced.

The utility model provides an indirect heat exchange type gasification fine slag resource utilization system, which realizes independent combustion of gasification fine slag, and utilizes waste heat energy generated by humidifying fine slag drying and combustion for recycling.

The utility model and its embodiments have been described above schematically, without limitation, and the utility model can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The representation in the drawings is only one of the embodiments of the utility model, the actual construction is not limited thereto, and any reference signs in the claims shall not limit the claims concerned. Therefore, if a person skilled in the art receives the teachings of the present invention, without inventive design, a similar structure and an embodiment to the above technical solution should be covered by the protection scope of the present patent. Furthermore, the word "comprising" does not exclude other elements or steps, and the word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. Several of the elements recited in the product claims may also be implemented by one element in software or hardware. The terms first, second, etc. are used to denote names, but not any particular order.

Claims

1. An indirect heat exchange type gasification fine slag resource utilization system is characterized by comprising a fine slag conveying system (1), a fine slag drying system (2), a dry slag storage unit (3), a fine slag combustion system (4), an air preheating system (5) and a flue gas treatment system (6);

the fine slag conveying system (1) is arranged at the foremost end of the system, and the output end of the fine slag conveying system (1) is connected with one input end of the fine slag drying system (2);

the fine slag drying system (2), the dry slag storage unit (3), the fine slag combustion system (4) and the air preheating system (5) are sequentially connected; the output end of the air preheating system (5) is connected with the other input end of the fine slag drying system (2);

the flue gas treatment system (6) is arranged at the tail end of the system, and the output end of the fine slag drying system (2) is connected with the input end of the flue gas treatment system (6).

2. The gasification fine slag resource utilization system according to claim 1, wherein a wet fine slag conveying channel is arranged between the fine slag conveying system (1) and the fine slag drying system (2).

3. The gasification fine slag resource utilization system according to claim 1, wherein an ash-containing flue gas conveying channel is arranged between the fine slag drying system (2) and the air preheating system (5), the dried fine slag is conveyed to the dry slag storage unit (3), and the ash-containing flue gas obtained after being conveyed to the fine slag drying system (2) by the air preheating system (5) and dried is conveyed to the flue gas treatment system (6).

4. The gasification fine slag resource utilization system according to claim 1, wherein the dry slag storage unit (3) is provided with a quantitative feeding device, and the quantitative feeding device mixes the dry fine slag with hot air preheated by the air preheating system (5) and then conveys the mixture to the fine slag combustion system (4) together as primary air of the fine slag combustion system (4).

5. The gasification fine slag resource utilization system as claimed in claim 1, wherein the fine slag combustion system (4) comprises a combustion furnace, and an adiabatic combustion section and a steam generation section are arranged in the combustion furnace.

6. The gasification fine slag resource utilization system according to claim 5,

the heat-insulation combustion section rapidly decarbonizes and combusts dry fine slag and hot air;

and the steam generation section mixes the high-temperature flue gas and water to obtain product steam and is used for controlling the temperature of ash-containing flue gas in the output end of the fine slag combustion system (4).

7. The gasification fine slag resource utilization system according to claim 1, wherein an ash-containing flue gas conveying channel is arranged between the air preheating system (5) and the fine slag combustion system, the air preheating system mixes ash-containing flue gas, which is conveyed by the fine slag combustion system (4) and formed by decarburization combustion, with air, and the hot air is obtained by indirect preheating.

8. The gasification fine slag resource utilization system according to claim 7, wherein an ash-containing flue gas conveying channel is arranged between the air preheating system (5) and the fine slag drying system, and the air preheating system conveys the ash-containing flue gas which is mixed with air and cooled to the fine slag drying system (2).

9. The gasification fine slag resource utilization system according to claim 1 or 3, wherein the flue gas treatment system (6) is provided with a discharge end for discharging ash-containing flue gas after dedusting.

10. The gasification fine slag resource utilization system according to claim 9, wherein a dust remover is arranged in the flue gas treatment system (6) and used for carrying out solid-gas separation on the dust-containing flue gas: collecting the solid part as fly ash by a dust remover; the dedusted flue gas is discharged to the atmosphere.