System for the processing of mixed shaped fuel by coupling sludge drying and carbonization with biomass

Abstract

System for the processing of mixed shaped fuel by coupling sludge drying and carbonization with biomass, characterized in that it comprises the following: a sludge treatment unit comprising a sludge conveying device (3) and a sludge drying and carbonization device (4) connected in series; a biomass energy conversion unit comprising a biomass gasification furnace (1) and a combustion furnace (2), wherein the gasification gas outlet of the biomass gasification furnace (1) is connected to the inlet of the combustion furnace (2) and the high temperature flue gas outlet of the combustion furnace (2) is connected to the inlet of the sludge drying and carbonization device (4); a mixed molding fuel processing unit comprising a twin-shaft mixer (6) and a molding machine (7), wherein the carbon outlet of the sludge drying and carbonization device (4) is successively connected to the twin-shaft mixer (6) and the molding machine (7); a gas purification plant comprising a cyclone dust separator (8), a spray tower (9), a condenser (10), an activated carbon adsorption plant (11), an induced draft fan (12) and a chimney (13) connected in series; wherein the air inlet of the cyclone dust separator (8) is connected to the exhaust gas outlet of the sludge drying and carbonization device (4).

Description

Technical area

[0001] The present utility model belongs to the technical field of solid waste treatment and energy recovery and relates to a system for the processing of mixed shaped fuel by coupling sludge drying and carbonization with biomass. Background technology

[0002] With the increasing capacity of urban wastewater treatment, sludge production is also rising rapidly. Sludge is rich in organic matter, heavy metals, pathogenic microorganisms, and various toxic and hazardous components. If it is not effectively treated and disposed of, it can easily lead to secondary pollution of soil, water, and air. Conventional sludge treatment methods such as landfilling, incineration, and composting are increasingly problematic, including low efficiency, significant resource waste, and high environmental risks, making them unable to meet ever-stricter environmental protection requirements. Among the various methods for utilizing sludge resources, the combined treatment of drying and pyrolysis carbonization has attracted considerable attention in recent years due to its dual benefits: waste reduction and energy recovery.During sludge drying and carbonization, moisture is effectively removed, and organic matter is pyrolyzed in the absence of oxygen. This process produces flammable gases, tar, and a solid, carbonaceous residue (sewage sludge char). Sewage sludge char is significantly smaller than the original sludge and has a larger surface area and a porous structure, which facilitates subsequent energy conversion and utilization.

[0003] Biomass such as straw and wood chips typically contain a high proportion of volatile components and carbon and have a high calorific value, making them well-suited for energy coupling with sewage sludge char. During the pyrolysis process, the volume of the sewage sludge char decreases significantly compared to the original sewage sludge, and its porous structure and large surface area improve fuel combustion efficiency. Combining sewage sludge char and biomass not only improves combustion efficiency but also reduces the risk of secondary pollution during sewage sludge disposal. The complementary nature of biomass makes its synergistic use with sewage sludge char a promising energy conversion potential.Suitable heat recovery and product mixing technologies can reduce operating costs while improving the overall energy efficiency of the system, complying with environmental standards, and increasing the economic benefits of sludge treatment.

[0004] In industrial practice, the synergistic use of sewage sludge char and biomass energy to create a continuous, efficient, and environmentally friendly integrated system still faces numerous technical challenges. For example, the efficient coupling of heat recovery, product blending, and fuel processing is a key element in realizing sludge resource utilization. Content of the utility model

[0005] In response to the problems of existing technology, the present utility model provides a system for the processing of mixed shaped fuel by coupling sludge drying and carbonization with biomass, which overcomes the shortcomings of existing sludge treatment technology such as low energy efficiency, weak ability to control pollutants and low resource utilization, and enables efficient and harmless treatment of sludge as well as high value-added resource utilization.

[0006] The present utility model is achieved through the following technical solutions: System for the processing of mixed shaped fuel by coupling sludge drying and carbonization with biomass, comprising: a sludge treatment unit comprising a sludge conveying device and a sludge drying and carbonization device connected in series; a biomass energy conversion unit comprising a biomass gasification furnace and a combustion furnace, wherein the gasification gas outlet of the biomass gasification furnace is connected to the inlet of the combustion furnace and the high-temperature flue gas outlet of the combustion furnace is connected to the inlet of the sludge drying and carbonization device; a mixed molding fuel processing unit comprising a twin-shaft mixer and a molding machine, wherein the carbon outlet of the sludge drying and carbonization device is successively connected to the twin-shaft mixer and the molding machine; a gas purification plant comprising a cyclone dust separator, a spray tower, a condenser, an activated carbon adsorption unit, an induced draft fan and a chimney connected in series; wherein the air inlet of the cyclone dust separator is connected to the exhaust gas outlet of the sludge drying and carbonization device; Preferably, the sludge conveying device incorporates a screw conveyor. Preferably, the sludge drying and carbonization device incorporates a rotating pyrolysis-carbonization furnace, which is internally equipped with a guide plate for moving the material forward.

[0007] Preferably, a first dosing scale is provided on the pipeline between the carbon outlet of the sludge drying and carbonization device and the twin-shaft mixer.

[0008] Preferably, a second dosing scale is provided between the twin-shaft mixer and the conveying line for the biomass raw material.

[0009] Preferably, the sludge drying and carbonization device carries out pyrolysis carbonization to produce sewage sludge coal by direct contact of high-temperature flue gas with sludge, wherein the biomass raw materials constitute 10-40 wt.% of the sewage sludge coal and are mixed and then processed by a forming machine into block, spherical or cylindrical granular fuel.

[0010] Preferably, the dimensions of a rectangular block of block-shaped fuel spread by the forming machine are 30 × 30 × (20-100) mm; the diameter of the spread spherical fuel is 30-70 mm; and the diameter of the spread cylindrical granular fuel is 6-30 mm with a length of 10-30 mm.

[0011] Preferably, the temperature of the high-temperature flue gas produced by the combustion furnace is regulated to 600-900 °C.

[0012] Preferably, the spray tower is equipped with a device for adding sodium hydroxide to neutralize acidic gases in the exhaust gas.

[0013] A process for the treatment of mixed shaped fuel by coupling sludge drying and carbonization with biomass, comprising the following steps: S1. Sludge transport: The sludge is transported to the sludge drying and carbonization unit via a sludge conveying device. S2. Sludge drying and carbonization: In the sludge drying and carbonization device, the hot flue gas from the combustion furnace is brought into direct contact with the sludge and simultaneously dried and carbonized to produce sewage sludge coal. S3. Exhaust gas treatment: The exhaust gas produced during sludge drying and carbonization enters a gas cleaning system, passes through the cyclone dust separator to remove particles, the spray tower to neutralize acidic gases, the condenser to condense water vapor, and the activated carbon adsorption system to remove odors, and is finally directed via the induced draft fan into the chimney to comply with emission standards; S4. Mixing the ingredients: Transport the sewage sludge coal and biomass raw materials prepared in step S2 separately or together to a twin-shaft mixer for mixing; S5. Forming: The uniformly mixed materials are placed in a forming machine and pressed into a mixed molding fuel.

[0014] Compared to the prior art, the present utility model exhibits the following advantageous technical effects: 1) The present utility model utilizes a synergistic use of sludge drying and carbonization equipment and biomass to achieve efficient sludge drying and carbonization, thereby effectively reducing the moisture content and volume of the sludge and thus achieving the goal of sludge reduction. Simultaneously, pollutants such as organic matter and pathogens are effectively removed from the sludge during the carbonization process, resulting in harmless sludge treatment. 2) The prepared mixed-fuel mixture contains sewage sludge coal in a ratio of 10-40%, thus optimally utilizing the strengths of the individual raw materials. Experimental tests show that the mixed-fuel mixture has good combustion efficiency, burns more completely compared to conventional fuels, and is able to effectively improve energy efficiency; and that at the same time, the pollutant emissions produced during the combustion of the mixed-fuel mixture are low, and the process is environmentally friendly. 3) The present utility model enables the resource utilization of sludge by converting it into a valuable mixed-fuel material, which reduces the costs of sludge treatment while simultaneously generating a certain energy gain. Furthermore, the system and process reduce the negative environmental impacts of conventional treatment methods such as sludge landfilling and incineration, offer significant environmental benefits, and meet the requirements of sustainable development. 4) The system provided in the present utility model for the processing of mixed shaped fuel by coupling sludge drying and carbonization with biomass is characterized by low operating costs, good sludge treatment effect and high technical feasibility, meeting national standards in all indicators and exhibiting significant practical value and promising development prospects. Figures

[0015] In order to illustrate the technical solution of the embodiments of the present utility model more clearly, the attached drawings, which must be used in the embodiments, are briefly presented below, and it should be understood that the following drawings show only some embodiments of the present utility model, so that they should not be regarded as limiting the scope, and for a generally technical person in the field, other relevant drawings can also be obtained from these drawings without creative work. Fig. Figure 1 is a schematic diagram of a system for the processing of mixed shaped fuel by coupling sludge drying and carbonization with biomass according to the present utility model;

[0016] In the figure: Biomass gasification furnace 1, combustion furnace 2, sludge conveying device 3, sludge drying and carbonization device 4, first dosing scale 5, twin-shaft mixer 6, forming machine 7, cyclone dust separator 8, spray tower 9, condenser 10, activated carbon adsorption system 11, induced draft fan 12, chimney 13, second dosing scale 14. Specific embodiments

[0017] The technical solutions of this utility model are described clearly and completely below, and it is obvious that the described embodiments represent only some of the embodiments of this utility model and not all of them. Based on the embodiments of this utility model, all other embodiments that ordinary technical personnel obtain without creative effort fall within the scope of protection of this utility model. Example 1

[0018] The present utility model provides a system and a process for the processing of mixed shaped fuel by coupling sludge drying and carbonization with biomass. As described in Fig. Figure 1 shows a system for processing mixed molded fuel by coupling sludge drying and carbonization with biomass, as described in the present utility model. The system comprises a sludge conveying device 3, a sludge drying and carbonization device 4, a biomass gasification furnace 1, a combustion furnace 2, a first metering scale 5, a twin-shaft mixer 6, a molding machine 7, a cyclone dust separator 8, a spray tower 9, a condenser 10, an activated carbon adsorption unit 11, an induced draft fan 12, a chimney 13, and a second metering scale 14.

[0019] The cyclone dust separator 8 and the spray tower 9 in the gas purification plant are both devices that meet industry standards.

[0020] The sludge drying and carbonization device incorporates a rotary pyrolysis furnace with a guide plate welded to the inner wall of the furnace, the guide plate having an inclination angle of 10°-30°; as the rotary furnace rotates, the guide plate can move the material forward for transport, and the biomass burner uses a high-efficiency biomass burner to generate high-temperature flue gas.

[0021] The processing unit for mixed molded fuel is equipped with a high-precision dosing scale, a twin-shaft mixer and a particle forming machine.

[0022] The municipal sludge with a moisture content of 80% is transported via a screw conveyor to the sludge drying and carbonization device.

[0023] The biomass passes through the gasification furnace and the combustion furnace to generate high-temperature flue gas with a temperature of 600 to 900 °C. This high-temperature flue gas then enters the sludge drying and carbonization unit for direct heat exchange with the sludge. After treatment, the moisture content of the sludge is reduced to approximately 8 to 40%, thus completing the drying and carbonization process to form sewage sludge char.

[0024] The exhaust gas produced during sludge drying and carbonization is successively fed into a cyclone dust separator to remove larger particles in the exhaust gas; The exhaust gas passes through a cyclone dust collector to remove larger particles; then it enters a spray tower where sodium hydroxide solution is added to neutralize the acidic gas; next, it enters a condenser to condense the water vapor in the waste; and finally, it passes through an activated carbon adsorption unit to remove the odor. After testing, the exhaust gas meets all local standards and is released into the atmosphere.

[0025] The processed sewage sludge char and the biomass are weighed separately using a high-precision dosing scale in a ratio of 10-40% of the mass fraction of the sewage sludge char and then transported to a twin-shaft mixer for stirring and mixing.

[0026] The mixed molded fuel is fed into the molding machine for pressing and shaping, and mixed molded fuel of varying sizes is prepared according to the actual conditions. The dimensions (length × width × height) of the block-shaped fuel formed by the molding machine are 30 × 30 × (20-100) mm; the diameter of the formed spherical fuel is 30-70 mm; and the diameter of the formed cylindrical fuel is 6-30 mm and the length 10-30 mm. Testing shows that the combustion properties of the mixed molded fuel are superior to those of simple sludge charcoal fuel. Example 2

[0027] The first dosing scale 5 and the second dosing scale 14 are high-precision dosing scales with a dosing accuracy of ± 0.5%; the twin-shaft mixer 6 is equipped internally with a built-in twin-screw agitator, the speed of which can be adjusted in the range of 30-60 rpm;

[0028] The forming machine 7 is equipped with an interchangeable mold to facilitate the forming of fuels of different specifications and shapes, and it is capable of processing fuels of the following specifications: Block-shaped fuel: A rectangular block with dimensions of 30 mm (L × W × H) × 30 mm (W × H) × 20-100 mm; Spherical fuel: A sphere with a diameter of 30-70 mm; cylindrical granular fuel: A cylinder with a diameter of 6-30 mm and a length of 10-30 mm.

[0029] The activated carbon adsorption unit 11 is filled with honeycomb-shaped activated carbon; The sludge drying and carbonization device 4 uses a pyrolysis carbonization furnace in which sludge and flue gas are subject to direct heat exchange, and material guide plates are provided on the inner wall of the carbonization furnace to ensure that the sludge is in full contact with the hot flue gas during forward movement.

[0030] The gas produced by the gasification of biomass in the biomass gasification furnace 1 enters the combustion furnace 2, where it is burned to produce high-temperature flue gas, and the temperature of the high-temperature flue gas produced by the combustion furnace is regulated to 600-900 °C.

[0031] The processing unit for mixed molded fuel is equipped with high-precision dosing and mixing devices that are able to precisely control the ratio of raw materials and the uniformity of the mixture.

[0032] The gas cleaning system comprises a cyclone dust collector 8, a spray tower 9, a condenser 10, and an activated carbon adsorption unit 11, connected in series. The exhaust gas enters the cyclone dust collector 8 to remove larger particles. It then proceeds to the spray tower 9, where sodium hydroxide solution is added to neutralize the acidic gas. Next, it enters the condenser 10 to condense the water vapor in the exhaust gas. Finally, the exhaust gas passes through the activated carbon adsorption unit 11 to remove odors, and the flue gas is discharged through the induced draft fan 12 into the chimney 13. After testing, the exhaust gas meets all local standards and is released into the atmosphere.

[0033] The sludge conveying device 3 uses a screw conveyor to continuously and stably convey the dewatered sludge to the drying and carbonation device, thus ensuring the airtightness and flowability of the feeding process.

[0034] The biomass gasification furnace 1 uses biomass particles or blocks as fuel, and the gasification gas produced by the gasification furnace enters the combustion furnace to generate high-temperature flue gas as a heat source for sludge drying and carbonization.

[0035] In the processing unit for mixed shaped fuel, the sewage sludge char is cooled and collected after production and mixed with biomass in a ratio of 10-40% of the mass fraction of the sewage sludge char and processed by processes such as stirring or granulation to create mixed shaped fuel for later combustion or sale.

[0036] It achieves an organic combination of sludge treatment, energy conversion, and flue gas cleaning to reduce the system's energy consumption and operating costs. Sewage sludge char exhibits high porosity and a large specific surface area and possesses good adsorption and combustion-enhancing properties; preferably, the synergistic combination of sewage sludge char and biomass improves the overall calorific value and utilization rate of the sewage sludge char fuel, reduces dependence on high-grade fuels, and realizes a resource-based approach of "waste treatment with waste."

[0037] The combustion furnace 2 features a multi-stage combustion chamber design capable of fully burning the fuel gas produced by biomass gasification and improving heat exchange efficiency.

[0038] The twin-shaft mixer 6 features a variable frequency setting design that is able to adjust the mixing rate according to the properties and proportions of different raw materials.

[0039] Exemplary embodiment 3: The workflow of the process provided by the present utility model for the processing of mixed molded fuel by coupling sludge drying and carbonization with biomass is as follows: 1) Continuous conveying of the sludge via the sludge conveying device 3 to the carbonization furnace of the sludge drying and carbonization device 4, wherein the residence time of the sludge in the furnace is 2-3 hours and the temperature is regulated to 400-500 °C in order to achieve sludge drying and preliminary carbonization and thus obtain sewage sludge coal. 2) Separate weighing of the processed sewage sludge char and the biomass using a high-precision dosing scale in a ratio of 10-40% of the mass fraction of the sewage sludge char and subsequent introduction into a twin-shaft mixer 6 for stirring and mixing at a mixing rate of 20-30 rpm. 3) Introducing the mixed materials into the molding machine 7 and pressing them into the desired fuel mold, with the molding pressure regulated to 12-15 MPa and the molding temperature being 80-100 °C. 4) Introducing the molding fuel into the cyclone dust separator 8 for pre-classification, whereby particles with a particle size greater than 2 mm are returned to the molding machine 7 for re-pressing and particles with a particle size less than 2 mm enter the spray tower 9. 5) Spraying the sodium hydroxide solution (concentration 30%) into the exhaust gas in the spray tower 9 to ensure complete contact with the exhaust gases and neutralize the acidic gas. The neutralized exhaust gas then enters the condenser 10, and the cooling temperature is regulated to 40–50 °C to condense the water vapor. 6) Introduction of the condensed exhaust gas into the activated carbon adsorption system 11, which uses the adsorption effect of the activated carbon to remove pollutants such as VOCs, H2S and NH3 from the exhaust gas and at the same time adsorbs a small amount of difficult-to-degrade pollutants such as dioxins. 7) The exhaust gas is discharged from the outlet of the activated carbon adsorption unit 11 by the induced draft fan 12 into the chimney 13, whereby the heat generated by combustion is recovered through the jacket and is designed for heating or other purposes. The entire system operates with stable and reliable performance and has a processing capacity of 10 to 20 tons of sludge per day with a treatment efficiency of over 95%.

[0040] It should be noted that the terms "first," "second," etc., are used in the description and claims of this utility model, as well as in the accompanying drawings, to distinguish similar objects and do not necessarily serve to describe a specific order or sequence. It is understood that the terms used in this way are interchangeable, so that the embodiments of this utility model described herein may be implemented in a different order than that shown or described here. Furthermore, the terms "comprise" and "feature," and all variations thereof, are intended to cover non-exclusive inclusion.For example, a process, procedure, system, product or device comprising a series of steps or units is not necessarily limited to the steps or units expressly listed, but may include further steps or units not expressly listed or inherent in such process, procedure, product or device.

[0041] Unless expressly stated otherwise and limited, the terms "install," "connect," "link," and "fasten" in this utility model are to be understood in a broad sense. For example, it may be a permanent connection, a detachable connection, or an integral connection; it may be a mechanical connection, an electrical connection, or a communicative connection; it may be a direct connection, an indirect connection via an intermediate medium, a connection within the two elements, or an interaction between the two elements. For general technical personnel in this field, the specific meaning of the aforementioned terms in this utility model may be understood according to the specific circumstances.When a component is described as "attached" to another component, it may be directly attached to the other component, or there may be an intervening component. When a component is described as "connected" to another component, it may be directly attached to the other component, or there may be an intervening component. When a component is described as "arranged on" another component, it may be arranged directly on top of the other component, or there may be an intervening component.

[0042] It is understood that the terms “comprise” and “contain” in this description and the accompanying claims indicate the presence of the described features, wholes, steps, operations, elements and / or assemblies, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, assemblies and / or combinations thereof.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as understood by a person skilled in the art in the field of this invention. The terminology used in the description of this utility model serves solely to describe specific embodiments and is not intended to limit the scope of this utility model. The term "and / or" used herein encompasses all combinations of one or more of the related listed elements.

[0044] The above description merely presents preferred embodiments of the present utility model and does not constitute any limitation of the present utility model; any generally skilled technical personnel in the industry can easily implement the present utility model as shown in the accompanying drawings of the description and as described above; however, equivalent changes, modifications and further developments made by those skilled in the art using the technical content disclosed above, without deviating from the scope of protection of the present utility model, all constitute equivalent embodiments of the present utility model; at the same time, all equivalent changes, modifications and further developments of the above embodiments that are based on the essential technology of the present utility model remain within the scope of protection of the present utility model.

Claims

[1] System for the processing of mixed shaped fuel by coupling sludge drying and carbonization with biomass, characterized by , that it includes the following: a sludge treatment unit comprising a sludge conveying device (3) and a sludge drying and carbonization device (4) connected in series; a biomass energy conversion unit comprising a biomass gasification furnace (1) and a combustion furnace (2), wherein the gasification gas outlet of the biomass gasification furnace (1) is connected to the inlet of the combustion furnace (2) and the high temperature flue gas outlet of the combustion furnace (2) is connected to the inlet of the sludge drying and carbonization device (4); a mixed molding fuel processing unit comprising a twin-shaft mixer (6) and a molding machine (7), wherein the carbon outlet of the sludge drying and carbonization device (4) is successively connected to the twin-shaft mixer (6) and the molding machine (7); a gas purification plant comprising a cyclone dust separator (8), a spray tower (9), a condenser (10), an activated carbon adsorption plant (11), an induced draft fan (12) and a chimney (13) connected in series; wherein the air inlet of the cyclone dust separator (8) is connected to the exhaust gas outlet of the sludge drying and carbonization device (4). [2] System for the processing of mixed shaped fuel by coupling sludge drying and carbonization with biomass according to claim 1, characterized by , that the sludge conveying device (3) takes over a conveying screw. [3] System for the processing of mixed shaped fuel by coupling sludge drying and carbonization with biomass according to claim 1, characterized by , that the sludge drying and carbonization device (4) incorporates a rotating pyrolysis carbonization furnace which is provided internally with a guide plate for moving the material forward. [4] System for the processing of mixed shaped fuel by coupling sludge drying and carbonization with biomass according to claim 1, characterized by , that a first dosing scale (5) is provided on the pipeline between the carbon outlet of the sludge drying and carbonization device (4) and the twin-shaft mixer (6). [5] System for the processing of mixed shaped fuel by coupling sludge drying and carbonization with biomass according to claim 1, characterized by, that a second dosing scale (14) is provided between the twin-shaft mixer (6) and the conveying line for the biomass raw material. [6] System for the processing of mixed shaped fuel by coupling sludge drying and carbonization with biomass according to claim 5, characterized by , that the dimensions length × width × height of the block-shaped fuel spread by the forming machine (7) are 30 × 30 × (20-100) mm; the diameter of the spread spherical fuel is 30-70 mm; and the diameter of the spread cylindrical granular fuel is 6-30 mm and the length is 10-30 mm.

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