Carbon black drying system
By combining a cyclone separator and an air classifier, combustible gas can be directly recovered for heating, eliminating the need for a dryer and a tail gas furnace. This solves the problem of flue gas desulfurization and denitrification in the carbon black drying system, achieving cost reduction and process simplification.
Patent Information
- Application Number
- CN202511572164.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-30
- Publication Date
- 2026-01-23
AI Technical Summary
The flue gas generated by the existing carbon black drying system needs to be desulfurized and denitrified, which increases production costs and environmental monitoring pressure. Moreover, the desulfurization and denitrification process is complex and costly.
A new process combining cyclone separators and air classifiers is adopted. Through contact heat exchange and nitrogen recycling, combustible gases are directly recovered for combustion heating, eliminating the need for dryers and tail gas furnaces, avoiding desulfurization and denitrification treatment, and reducing production costs.
It reduced production costs, simplified the process flow, improved exhaust gas quality, reduced investment and operating costs of environmental protection equipment, and avoided the environmental pressure of desulfurization and denitrification treatment.
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Figure CN121383604A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of carbon black production technology, specifically a carbon black drying system. Background Technology
[0002] In carbon black production, air and coal gas are burned in reactor 1 to pyrolyze the feedstock oil at high temperature, producing powdered carbon black and a high-temperature gas-solid mixture containing combustible gas with a lower calorific value than coal gas (hereinafter referred to as tail gas). In existing carbon black drying systems, such as... Figure 1 As shown, after the high-temperature gas-solid mixture passes through the high-temperature air preheater 2, waste heat boiler 3, oil preheater 4 for heat exchange and is cooled by water spraying through the venturi tube 5, the high-temperature gas-solid mixture is reduced from about 900°C to about 250°C. Then, it passes through the main bag filter 6 for gas-solid separation, which separates the tail gas and powdered carbon black. The separated tail gas enters the tail gas furnace 13 for combustion to produce high-temperature flue gas and enters the dryer 12. The separated powdered carbon black is pneumatically conveyed by the blower 9 and then separated through the main vein bag filter 10. The separated gas is discharged. The separated powdered carbon black is wet granulated by the granulator 11 and then enters the dryer 12 for drying. The dried granulated carbon black is cooled by the air classifier 15 and separated from the residual powdered carbon black before entering the carbon black storage system 16. The dried flue gas contains a large amount of water vapor and a small amount of powdered carbon black due to incomplete granulation. It enters the bag filter 7 through the exhaust fan 8 for gas-solid separation. The separated powdered carbon black returns to the blower for recycling, granulation and drying. The separated flue gas needs to enter the desulfurization and denitrification system for separate desulfurization and denitrification. However, because the flue gas contains a large amount of water vapor, it is easy to cause serious corrosion to the gas transmission pipeline. At the same time, desulfurization and denitrification are environmental protection processes and are subject to environmental monitoring at all times. Exceeding emission standards will result in fines. In addition, the treatment of hazardous waste generated by desulfurization and denitrification also requires expenditure, which increases production costs. Summary of the Invention
[0003] In order to solve the technical problem that the flue gas generated by the carbon black drying system in the background art needs to be desulfurized and denitrified, the present invention provides a new carbon black drying system.
[0004] This invention is achieved using the following technical solution: A carbon black drying system, comprising a cyclone separator, tail gas and powdery carbon black separated by the cyclone separator enter a main bag filter after being cooled by cooling water of a venturi tube, a tail gas outlet of the main bag filter is used for discharging tail gas, powdery carbon black treated by the main bag filter enters from a pipeline before an inlet of the cyclone separator after a forced air fan and a granulator, and forms high-temperature dry granular carbon black after being in contact with a high-temperature gas-solid mixture generated after combustion reaction of a reaction furnace, the high-temperature dry granular carbon black and the high-temperature gas-solid mixture after heat exchange enter the inlet of the cyclone separator, high-temperature dry granular carbon black discharged from a lower part of the cyclone separator is separated into residual powdery carbon black and low-temperature dry granular carbon black after heat exchange and screening by an air classifier, the low-temperature dry granular carbon black is transported to a carbon black storage system, and the residual powdery carbon black enters the granulator for regranulation after the forced air fan.
[0005] Principle: The tail gas separated by the main bag filter is directly discharged (the tail gas at this point is combustible gas, and the tail gas described in the present application is combustible gas, which can be directly recycled for combustion heating), the powdery carbon black separated by the main bag filter enters the granulator for wet granulation to form wet granular carbon black by the forced air fan, the wet granular carbon black and the high-temperature gas-solid mixture generated by the reaction of the reaction furnace are in contact for heat exchange, so that the water in the wet granular carbon black evaporates and cools down, replacing part of the cooling water in the venturi tube, so that the composition of the tail gas as a whole is not affected, both drying of the wet granular carbon black and partial cooling of the powdery carbon black entering the main bag filter are completed, the dryer and the tail gas furnace are saved, the desulfurization and denitrification treatment process of flue gas generated after combustion of the tail gas furnace is avoided, and the production cost is reduced; at the same time, the high-temperature dry granular carbon black screened by the cyclone separator is separated into low-temperature dry granular carbon black and residual powdery carbon black after cooling and screening by the air classifier, the low-temperature dry granular carbon black is output to the carbon black storage system, and the residual powdery carbon black enters the granulator for regranulation after the forced air fan; the tail gas and powdery carbon black screened by the cyclone separator enter the main bag filter after being cooled by the cooling water of the venturi tube.
[0006] Further, the nitrogen gas outlet of the air classifier is communicated with the nitrogen gas pressurizing fan, the solid outlet of the backflushing bag filter is communicated with the inlet of the air feeding fan, the nitrogen gas inlet of the air classifier is communicated with the nitrogen gas pipeline, and the gas outlet of the backflushing bag filter is communicated with the nitrogen gas channel after passing through the nitrogen gas cooler. The high-temperature dry granular carbon black obtained through the cyclone separator has a temperature of about 300 DEG C and is oxidized on the surface when meeting air, and the high-temperature carbon black is inconvenient for later packaging. Meanwhile, in the separation of the cyclone separator, the dry granular carbon black carries part of the powdery carbon black, so the high-temperature dry granular carbon black is subjected to heat exchange and screening through the air classifier, and nitrogen gas is selected as the gas medium entering the air classifier. Nitrogen gas is an inert gas and cannot cause oxidation reaction, so the quality of the carbon black is ensured. In addition, the pure high-temperature nitrogen gas separated through the backflushing bag filter is cooled through the nitrogen gas cooler and can be introduced into the air classifier again to cool the high-temperature dry granular carbon black, so that the nitrogen gas is recycled.
[0007] Further, the gas outlet of the backflushing bag filter is also communicated with the backflushing port of the backflushing bag filter through the nitrogen gas backflushing fan, so that the backflushing bag filter can be swept.
[0008] Further, the reaction furnace is provided with an air inlet, a raw oil inlet, a coal gas inlet and a high-temperature gas-solid mixture outlet. The air is heated through the high-temperature air preheater and then enters the air inlet of the reaction furnace. The raw oil is heated through the oil preheater and then enters the raw oil inlet of the reaction furnace. The high-temperature gas-solid mixture outlet of the reaction furnace is communicated with the inlet of the cyclone separator in sequence after passing through the high-temperature air preheater, the waste heat boiler and the oil preheater. The heat exchange part is specific and standardized, and the heat exchange efficiency is further improved.
[0009] Further, the main pulse bag filter is arranged between the granulator and the air feeding fan. The residual tail gas in the powdery carbon black is separated and discharged through the powdery carbon black.
[0010] Further, the low-temperature dry powdery carbon black after heat exchange and screening through the air classifier is conveyed to the carbon black storage system through the elevator, and the production process is standardized.
[0011] The beneficial effects of the present application are as follows: 1) the new process cancels the tail gas combustion system, thereby directly eliminating the dryer and tail gas furnace equipment, and adding the cyclone separator, so that the initial investment capital for the design of carbon black production is reduced; 2) the new process cancels the tail gas combustion system, thereby indirectly canceling the waste gas desulfurization and denitrification section of the carbon black industry, eliminating the environmental protection equipment for desulfurization and denitrification and daily maintenance and hazardous waste treatment, reducing the initial investment cost and daily operation cost; 3) the old process uses cooling water to reduce the temperature of the gas-solid mixture of the tail gas and the powdery carbon black to 250 DEG C, while the new process takes away part of the heat energy of the high-temperature dry carbon black, so that the overall cooling water volume is reduced, the water vapor content in the tail gas is lower than that of the existing process, and the tail gas quality is improved. BRIEF DESCRIPTION OF DRAWINGS
[0012] The accompanying drawings, which are incorporated herein and constitute part of the specification, illustrate embodiments consistent with the present application and, together with the description, further serve to explain the principles of the application.
[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, those skilled in the art can obtain other drawings according to these drawings without any creative effort.
[0014] Figure 1 It is a schematic diagram of the existing carbon black drying system. Figure 2 It is a schematic diagram of the carbon black drying system according to the present application.
[0015] In the figure: 1-reaction furnace, 2-high temperature air preheater, 3-waste heat boiler, 4-oil preheater, 5-venturi tube, 6-main bag filter, 7-discharge bag filter, 8-exhaust fan, 9-air blowing fan, 10-main vein bag filter, 11-pelletizer, 12-dryer, 13-tail gas furnace, 14-elevator, 15-air separator, 16-carbon black storage system, 17-cyclone separator, 18-nitrogen pressurizing fan, 19-back flushing bag filter, 20-nitrogen back flushing fan, 21-nitrogen cooler. DETAILED DESCRIPTION
[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, those skilled in the art can obtain other drawings according to these drawings without any creative effort.
[0017] In the description, it should be noted that the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance. It should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.
[0018] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application, but the present application can also be implemented in other ways different from those described herein; obviously, the examples in the specification are only some of the embodiments of the present application, not all the embodiments.
[0019] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.
[0020] As Figure 2 shown, a carbon black drying system, including a cyclone separator 17, the tail gas and the powdered carbon black separated by the cyclone separator 17 are cooled by the cooling water of the venturi tube 5 and then enter the main bag filter 6, the tail gas outlet of the main bag filter 6 is used to discharge the tail gas, the powdered carbon black treated by the main bag filter 6 enters the pipeline in front of the inlet of the cyclone separator 17 through the air blower 9 and the granulator 11, and after being contacted and heat-exchanged with the high-temperature gas-solid mixture generated after the combustion reaction of the reaction furnace 1, high-temperature dry granular carbon black is formed, the high-temperature dry granular carbon black is then entered into the inlet of the cyclone separator 17 together with the high-temperature gas-solid mixture after heat exchange, the high-temperature dry granular carbon black discharged from the lower part of the cyclone separator 17 is heat-exchanged and screened by the air classifier 15, and then divided into residual powdered carbon black and low-temperature dry granular carbon black, the low-temperature dry granular carbon black is transported to the carbon black storage system 16, and the residual powdered carbon black enters the granulator 11 for re-granulation after the air blower 9.
[0021] Principle: The tail gas separated by the main bag filter 6 is directly discharged (the tail gas at this point is a combustible gas, and all the tail gas described in this application is a combustible gas, which can be directly recycled for combustion heating), the powdered carbon black separated by the main bag filter 6 enters the granulator 11 through the air blower 9 for wet granulation to form wet granular carbon black, and the wet granular carbon black is heat-exchanged with the high-temperature gas-solid mixture generated by the reaction of the reaction furnace 1, so that the water in the wet granular carbon black evaporates and cools down, replacing part of the cooling water in the venturi tube 5, so as not to affect the composition of the whole tail gas, thus completing the drying of the wet granular carbon black and the partial cooling of the powdered carbon black entering the main bag filter 6, saving the dryer 12 and the tail gas furnace 13, avoiding the desulfurization and denitrification treatment process of the flue gas generated after the combustion of the tail gas furnace 13, and reducing the production cost; at the same time, the high-temperature dry granular carbon black screened by the cyclone separator 17 is cooled and screened by the air classifier 15, and then divided into low-temperature dry granular carbon black and residual powdered carbon black, the low-temperature dry granular carbon black is output to the carbon black storage system 16, and the residual powdered carbon black enters the granulator 11 for re-granulation after entering the air classifier; the tail gas and the powdered carbon black screened by the cyclone separator 17 are cooled by the cooling water of the venturi tube 5 and then enter the main bag filter 6.
[0022] In the embodiment, the nitrogen outlet of the air classifier 15 is communicated with the nitrogen pressurizing fan 18 and the material inlet of the backflush bag filter 19, the solid outlet of the backflush bag filter 19 is communicated with the inlet of the air conveying fan 9, the nitrogen inlet of the air classifier 15 is communicated with the nitrogen pipeline, and the gas outlet of the backflush bag filter 19 is communicated with the nitrogen channel after passing through the nitrogen cooler 21. The high-temperature dry granular carbon black obtained by the cyclone separator 17 has a temperature of about 300 DEG C, and will be oxidized when meeting air. In addition, the high-temperature dry granular carbon black is mixed with some powder carbon black. Therefore, the high-temperature dry granular carbon black is subjected to heat exchange and screening by the air classifier 15, and nitrogen is selected as the gas medium. Nitrogen is an inert gas, and will not cause oxidation reaction, thereby ensuring the quality of the carbon black. In addition, the pure high-temperature nitrogen separated by the backflush bag filter 19 is cooled by the nitrogen cooler 21, and then is introduced into the air classifier 15 again, so as to cool the high-temperature dry granular carbon black and realize the recycling of nitrogen.
[0023] In the embodiment, the gas outlet of the backflush bag filter 19 is further communicated with the backflush port of the backflush bag filter 19 through the nitrogen backflush fan 20, so as to facilitate the purging of the backflush bag filter 19.
[0024] In the embodiment, the reaction furnace 1 is provided with an air inlet, a raw oil inlet, a gas inlet and a high-temperature gas-solid mixture outlet. The air is heated by the high-temperature air preheater 2, and then is introduced into the air inlet of the reaction furnace 1. The raw oil is heated by the oil preheater 4, and then is introduced into the raw oil inlet of the reaction furnace 1. The high-temperature gas-solid mixture outlet of the reaction furnace 1 is communicated with the inlet of the cyclone separator 17 in sequence through the high-temperature air preheater 2, the waste heat boiler 3 and the oil preheater 4. The heat exchange part is specified and standardized, thereby further improving the heat exchange efficiency.
[0025] In the embodiment, the main pulse bag filter 10 is further arranged between the granulator 11 and the air conveying fan 9. The residual tail gas in the powder carbon black is separated and discharged by the powder carbon black.
[0026] In the embodiment, the low-temperature dry powder carbon black subjected to heat exchange and screening by the air classifier 15 is conveyed to the carbon black storage system 16 by the elevator 14, thereby standardizing the production process.
[0027] The above description is only the embodiment of the present application, and enables those skilled in the art to understand or implement the present application. Although the foregoing embodiments are described in detail, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some or all of the technical features can be replaced by equivalents. The modification or replacement does not change the essence of the corresponding technical solution, and should be covered by the protection scope of the claims.
Claims
1. A carbon black drying system, characterized in that, The system includes a cyclone separator (17). The tail gas and powdered carbon black separated by the cyclone separator (17) are cooled by cooling water in the venturi tube (5) and then enter the main bag filter (6). The tail gas outlet of the main bag filter (6) is used to discharge the tail gas. The powdered carbon black processed by the main bag filter (6) enters the inlet pipe of the cyclone separator (17) after passing through the blower (9) and the granulator (11), and is contact-type exchanged with the high-temperature gas-solid mixture generated after combustion reaction in the reactor (1). After heating, high-temperature dry granular carbon black is formed. The high-temperature dry granular carbon black and the high-temperature gas-solid mixture after heat exchange are then fed into the inlet of the cyclone separator (17). The high-temperature dry granular carbon black discharged from the bottom of the cyclone separator (17) is separated into residual powdered carbon black and low-temperature dry granular carbon black after heat exchange and screening by the air classifier (15). The low-temperature dry granular carbon black is transported to the carbon black storage system (16). The residual powdered carbon black is fed into the granulator (11) by the air blower (9) for regranulation.
2. The carbon black drying system according to claim 1, characterized in that, The nitrogen outlet of the air separator (15) is connected to the nitrogen pressurizing blower (18) and the material inlet of the backflush bag filter (19). The solid outlet of the backflush bag filter (19) is connected to the inlet of the air blower (9). The nitrogen inlet of the air separator (15) is connected to the nitrogen pipeline. The gas outlet of the backflush bag filter (19) is connected to the nitrogen channel after passing through the nitrogen cooler (21).
3. The carbon black drying system according to claim 2, characterized in that, The gas outlet of the backflush bag filter (19) is also connected to the backflush port of the backflush bag filter (19) via a nitrogen backflush blower (20).
4. The carbon black drying system according to claim 3, characterized in that, The reactor (1) is equipped with an air inlet, a raw oil inlet, a gas inlet, and a high-temperature gas-solid mixture outlet. The air enters the air inlet of the reactor (1) after being heated by the high-temperature air preheater (2). The raw oil enters the raw oil inlet of the reactor (1) after being heated by the oil preheater (4). The high-temperature gas-solid mixture outlet of the reactor (1) is connected to the inlet of the cyclone separator (17) after passing through the high-temperature air preheater (2), the waste heat boiler (3), and the oil preheater (4) in sequence.
5. A carbon black drying system according to claim 4, characterized in that, A main vein bag filter (10) is also provided between the granulator (11) and the blower (9).
6. A carbon black drying system according to claim 5, characterized in that, After being heated and screened by the air separator (15), the low-temperature dry powder carbon black is transported to the carbon black storage system (16) by the elevator (14).