A device for producing carbon from sewage sludge by smoldering driven pyrolysis

Abstract

The present application relates to sludge treatment technical field, specifically disclose a kind of by smoldering drive sewage sludge pyrolysis carbon device, comprising: smoldering combustion chamber, inside it is equipped with the feeder that can contain sludge to be pyrolyzed and remain, and the feeder with the smoldering combustion chamber carries out heat interaction;Nitrogen gas pipeline, with the feeder communication, provides inert environment for sludge pyrolysis reaction;Smoldering combustion chamber is configured with smoldering sludge, smoldering sludge is in smoldering state and heats sludge to be pyrolyzed in feeder to pyrolysis temperature, the present application can recycle the heat generated by sludge smoldering, convert it into other sludge heating energy, so that sludge pyrolysis generates biochar, break through the maximum economic bottleneck of traditional sludge pyrolysis high energy consumption, reduce sludge treatment cost, can realize sludge reduction and harmlessness with lower cost, also achieve the purpose of resource recycling for part of sludge.

Description

Technical Field

[0001] This application relates to the field of sludge treatment technology, and specifically discloses a wastewater sludge pyrolysis charcoal production device driven by smoldering. Background Technology

[0002] With the acceleration of urbanization and the widespread adoption of sewage treatment facilities, the total amount of sludge produced by sewage treatment plants, as a major byproduct, is increasing daily. Sludge has a complex composition, containing a large number of pathogens, heavy metals, organic pollutants, and other harmful substances. If improperly handled and directly dumped or landfilled, it can easily cause secondary pollution to soil, air, and groundwater, threatening the ecological environment and human health.

[0003] Currently, common sludge disposal methods mainly include sanitary landfill, land application, pyrolysis gasification, and incineration, but these methods all have certain limitations in practical applications. (1) Although sanitary landfill and land use methods are relatively simple to operate, they require a large amount of land resources, and harmful substances in sludge may seep into the soil during long-term accumulation, causing persistent pollution and even affecting human health through the food chain.

[0004] (2) Pyrolysis and gasification technologies can convert sludge into resource-based products such as biochar, realizing the recovery of energy and materials from sludge. However, this process requires continuous external energy input to maintain the reaction temperature, which leads to a significant increase in system operating costs and poor economic efficiency.

[0005] (3) Although incineration technology can achieve rapid reduction and harmless treatment of sludge, the sludge generally has a high moisture content. Direct incineration consumes a lot of heat energy due to water evaporation, resulting in a low effective calorific value of the fuel and easy combustion instability or even flameout. In addition, sludge usually needs to be pre-dried or supplemented with auxiliary fuel, which not only increases the complexity of the treatment process, but also makes the overall energy consumption and operating costs high.

[0006] In summary, current sludge treatment technologies either pose risks to environmental safety or face challenges in terms of energy economy. Therefore, this invention provides a smoldering-driven wastewater sludge pyrolysis carbonization device to solve the above problems. Summary of the Invention

[0007] The purpose of this invention is to provide a wastewater sludge pyrolysis carbonization device that can reduce and render harmless sludge at a lower cost, while also achieving resource recovery of some of the sludge.

[0008] To achieve the above objectives, the basic solution of the present invention provides a wastewater sludge pyrolysis charcoal production device driven by smoldering combustion, comprising: The smoldering combustion chamber is equipped with a feeder that can accommodate the conveying and storage of pyrolysis sludge, and the feeder exchanges heat with the smoldering combustion chamber. A nitrogen pipeline, connected to the feeder, provides an inert environment for the sludge pyrolysis reaction; The smoldering combustion chamber is equipped with smoldering sludge, which is in a smoldering state and heats the sludge to be pyrolyzed in the feeder to the pyrolysis temperature.

[0009] Furthermore, the top and bottom of the smoldering combustion chamber are respectively provided with a smoldering preheating chamber and a smoldering ash chamber; A first baffle plate is provided between the smoldering preheating chamber and the smoldering combustion chamber; A grate is provided between the smoldering combustion chamber and the smoldering ash chamber.

[0010] Furthermore, the side wall of the smoldering preheating chamber is connected to a flue gas duct, and the top of the feeder is provided with a flue gas branch pipe connected to the flue gas duct to allow the flue gas generated by pyrolysis to be discharged.

[0011] Furthermore, the combustion ash chamber is equipped with a detection component for detecting the weight of accumulated ash, and the bottom side of the combustion ash chamber is connected to an ash discharge pipe, which is equipped with an actuator for discharging ash.

[0012] Furthermore, the detection component includes: A fixing plate is located at the inner bottom of the smoldering ash chamber; The movable plate is vertically and movably connected to the fixed plate and is used to bear ash and slag; Several elastic elements are disposed between the fixed plate and the movable plate; As the amount of ash and slag carried on the movable plate increases, the elastic element is further compressed, causing the movable plate to move toward the fixed plate.

[0013] Furthermore, it also includes a triggering mechanism for triggering the actuator to open, comprising: The first moving contact is connected to the movable plate and moves synchronously with the movable plate; The first stationary contact is connected to the fixed plate and can be electrically connected to the first moving contact; The actuator is activated when the first moving contact makes electrical contact with the first stationary contact.

[0014] Furthermore, the fixed plate is provided with a column sleeve, and the movable plate is provided with a guide post that is slidably connected to the column sleeve. The first moving contact is located on the outer wall of the guide post, and the first stationary contact is located on the inner wall of the column sleeve.

[0015] Furthermore, the triggering mechanism also includes: The second moving contact and the second stationary contact are respectively located on the outer wall of the guide post and the inner wall of the post sleeve; A normally open relay is installed in the circuit between the power supply and the actuator. When the first moving contact makes electrical contact with the first stationary contact, the normally open relay is energized. A normally closed relay is connected in series with the normally open relay, and the normally closed relay is energized when the second moving contact is in electrical contact with the second stationary contact; A holding relay, wherein the coil of the holding relay is connected in series with the normally open relay, and the normally open contact of the holding relay is connected in parallel with the normally open relay.

[0016] Furthermore, an air diffuser is provided at the bottom of the smoldering combustion chamber, including a coil located inside the smoldering combustion chamber and a connecting pipe communicating with the coil, and the coil is provided with several air inlets.

[0017] Furthermore, the wall of the smoldering combustion chamber is provided with a heat insulation protective layer.

[0018] The principle and effect of this solution are as follows: This invention can recover and utilize the heat generated by the smoldering of sludge, converting it into energy for heating other sludge, so that the sludge can be pyrolyzed to produce biochar. This breaks through the biggest economic bottleneck of high energy consumption in traditional sludge pyrolysis, reduces the cost of sludge treatment, and can achieve sludge reduction and harmlessness at a lower cost, while also achieving the goal of resource recovery of some sludge.

[0019] This invention, through independently adjustable air diffusers, feeders, and first baffle plates, can create the most suitable temperature and time conditions for the pyrolysis process, ensuring stable and continuous smoldering, an inert environment for pyrolysis, and controllable material transport. The system is reliable and flexible in operation, thereby obtaining higher performance biochar.

[0020] The trigger mechanism of this invention can not only automatically control the opening of the actuator in the set state, but also keep the actuator open for a certain period of time and automatically close the actuator after the ash and slag are discharged.

[0021] This invention integrates multiple units such as drying, smoldering, pyrolysis, heat recovery, and atmosphere control into a single reactor. The equipment has a small footprint, low heat loss, and a compact process flow, reducing piping connections and auxiliary equipment, thus lowering investment and operational complexity. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This illustration shows a schematic diagram of a wastewater sludge pyrolysis charcoal production device driven by smoldering according to an embodiment of this application; Figure 2 This illustration shows a front view of the reactor interior in a smoldering-driven pyrolysis carbonization apparatus for wastewater sludge, according to an embodiment of this application. Figure 3 This illustration shows a partial mechanical connection diagram of the triggering mechanism in a smoldering-driven wastewater sludge pyrolysis charcoal production device according to an embodiment of this application. Figure 4 This illustration shows a partial circuit connection diagram of the triggering mechanism in a smoldering-driven wastewater sludge pyrolysis charcoal production device according to an embodiment of this application. Detailed Implementation

[0024] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0025] The reference numerals in the accompanying drawings include: reactor 1, smoldering combustion chamber 2, first baffle plate 3, grate 4, detection component 5, fixed plate 501, movable plate 502, smoldering ash chamber 6, storage chamber 7, smoldering preheating chamber 8, fuel pipeline 9, ash discharge pipeline 10, air diffuser 11, flue gas pipeline 12, conveying cylinder 13, spiral roller 14, feed hopper 15, feed valve 16, flue gas branch pipe 17, discharge valve 18, nitrogen pipeline 19, elastic element 20, guide column 21, column sleeve 22, connecting ring 23, first moving contact 24, second moving contact 25, first stationary contact 26, second stationary contact 27, normally open relay 28, holding relay 29, holding relay coil 2901, holding relay normally open contact 2902, normally closed relay 30.

[0026] A smoldering-driven wastewater sludge pyrolysis carbonization device, implementing, for example... Figure 1 and Figure 2As shown: It includes a reactor 1 and a feeder. The bottom of the reactor 1 is fixed by a bottom plate, and the top of the reactor 1 is equipped with a top plate. Inside the reactor 1, a first baffle plate 3, a grate 4 and a fixing plate 501 are arranged in sequence. The space between the top plate and the first baffle plate 3 is a smoldering preheating chamber 8; the space between the first baffle plate 3 and the grate 4 is a smoldering combustion chamber 2; and the space between the grate 4 and the fixing plate 501 is a smoldering ash chamber 6.

[0027] Fuel pipes 9 and flue gas pipes 12 are respectively installed on both sides of the smoldering preheating chamber 8, allowing smoldering sludge to enter the smoldering preheating chamber 8 for temporary storage. The flue gas generated during smoldering preheats the sludge in the smoldering preheating chamber 8 before being discharged. In practice, sludge with a moisture content of 80% or raw sludge or wet sludge can meet the smoldering standard. For conventional sludge products from wastewater treatment, no additional drying or other pretreatment is required to meet the energy release requirements of smoldering. The operation process is more convenient and reduces the processing cost compared to conventional methods. By controlling the opening of the first baffle plate 3, the falling speed and amount of sludge falling into the smoldering combustion chamber 2 can be controlled. The ash and slag produced after smoldering fall into the smoldering ash and slag chamber 6 through the grate 4. An ash discharge pipe 10 is installed on the side wall of the smoldering ash and slag chamber 6, and an actuator is installed on the ash discharge pipe 10 to discharge the ash and slag.

[0028] The feeder is a screw conveyor, which is vertically installed at the center of the reactor 1. The power end of the screw conveyor is installed on the top plate to drive the screw conveyor to rotate. The conveying cylinder 13 of the screw conveyor interacts with the inside of the reactor 1 in terms of heat. A pyrolysis chamber is formed inside the conveying cylinder 13. The screw roller 14 of the screw conveyor rotates inside the conveying cylinder 13. The top and bottom side walls of the conveying cylinder 13 are respectively connected to the feed pipe and the discharge pipe. The feed pipe and the discharge pipe are respectively equipped with the feed valve 16 and the discharge valve 18. The feed valve 16 and the discharge valve 18 are normally closed to ensure the oxygen-free conditions in the pyrolysis chamber. The top side wall of the conveying cylinder 13 is provided with a flue gas branch pipe 17 connected to the flue gas pipe 12 to discharge the flue gas generated by pyrolysis.

[0029] A biochar storage chamber 7 is formed between the fixed plate 501 and the bottom of the reactor 1. A feed hopper 15 is installed on the top of the feed valve 16. The bottom of the discharge pipe extends into the storage chamber 7. An openable sealing door is installed on the side wall of the storage chamber 7 to periodically remove the biochar generated by pyrolysis. At the same time, a second baffle is installed at the bottom of the conveying cylinder 13 to control the speed at which the biochar and sludge in the pyrolysis chamber enter the discharge pipe by controlling the opening of the second baffle.

[0030] A nitrogen pipe 19 is connected to the side wall of the discharge pipe to provide an inert environment for the sludge pyrolysis reaction.

[0031] In this embodiment, smoldering sludge is temporarily stored in fuel pipe 9. Part of the smoldering sludge falls into smoldering combustion chamber 2 and is ignited via a gas nozzle, maintaining a smoldering state after ignition. Meanwhile, the sludge to be pyrolyzed enters the screw conveyor from feed hopper 15 and feed pipe. The power end of the screw conveyor drives the screw roller 14 to rotate, causing the sludge to be pyrolyzed to move along conveyor cylinder 13 or remain within it. The smoldering sludge heats smoldering combustion chamber 2 and the pyrolysis chamber, causing the sludge in the pyrolysis chamber to pyrolyze and generate biochar. The generated biochar is temporarily stored in biochar storage chamber 7. The ash produced after smoldering falls through grate 4 into smoldering ash chamber 6 and is discharged through ash discharge pipe 10.

[0032] This embodiment can recover and utilize the heat generated by the smoldering of sludge, converting it into energy for heating other sludge, so that the sludge can be pyrolyzed to produce biochar. This breaks through the biggest economic bottleneck of high energy consumption in traditional sludge pyrolysis, reduces the cost of sludge treatment, and can achieve sludge reduction and harmlessness at a lower cost, while also achieving the goal of resource recovery of some sludge.

[0033] In one possible embodiment, the wall of the smoldering combustion chamber 2 is provided with a heat insulation layer to reduce heat transfer to the outside, and an air diffuser 11 is provided at the bottom of the smoldering combustion chamber 2, including a coil disposed in the smoldering combustion chamber 2 and a connecting pipe communicating with the coil, and the coil is provided with several air inlets. This ensures that air is uniformly supplied to the inside of the combustion chamber, and the characteristic temperature of the smoldering reaction can be controlled by adjusting the air flow rate to ensure the optimal temperature required by the pyrolysis chamber.

[0034] In one possible embodiment, a movable plate 502 is disposed directly above the fixed plate 501. The movable plate 502 is slidably connected to the inner wall of the reactor 1, and a sealing ring is disposed at the edge of the movable plate 502 between the reactor 1. The movable plate 502 and the fixed plate 501 are connected by multiple elastic elements 20, which can be springs. The movable plate 502, the fixed plate 501, and the elastic elements 20 constitute a detection component 5 for detecting the weight of accumulated ash and slag. When the amount of ash and slag carried on the movable plate 502 increases, the elastic elements 20 are further compressed, causing the movable plate 502 to move towards the fixed plate 501. Thus, the amount of ash and slag accumulated on the movable plate 502 can be detected by detecting the deformation of the elastic elements 20 or the position of the movable plate 502, thereby adjusting whether the actuator is opened or closed.

[0035] In one possible embodiment, the actuator is an electrically controlled valve or a pump, and the power supply to and from the actuator is controlled by a triggering mechanism, such as... Figure 3As shown, a column sleeve 22 is provided on the fixed plate 501, and a guide post 21 is provided on the movable plate 502 that is slidably connected to the column sleeve 22. The inner bottom and inner top of the column sleeve 22 are respectively provided with a first stationary contact 26 and a second stationary contact 27. A connecting ring 23 is provided on the guide post 21, and the bottom and top of the connecting ring 23 are respectively provided with a first moving contact 24 and a second moving contact 25.

[0036] like Figure 4 As shown, a normally open relay 28, a normally closed relay 30, and a holding relay 29 are provided between the power supply and the actuator. When the first moving contact 24 is electrically connected to the first stationary contact 26, the coil of the normally open relay 28 is energized and the normally open contact of the normally open relay 28 is closed. When the second moving contact 25 is electrically connected to the second stationary contact 27, the coil of the normally closed relay 30 is energized and the normally closed contact of the normally closed relay 30 is opened. The holding relay coil 2901 is connected in series with the normally open contact of the normally open relay 28, and the holding relay normally open contact 2902 is connected in parallel with the normally open contact of the normally open relay 28.

[0037] As the amount of ash on the movable plate 502 gradually increases, the movable plate 502 gradually moves downward until the first moving contact 24 and the first stationary contact 26 make electrical contact. The coil of the normally open relay 28 is energized, causing the normally open contact of the normally open relay 28 to close. This supplies power to the actuator and also energizes the coil of the holding relay 2901, thereby causing the normally open contact of the holding relay 2902 to close. Even if the ash is discharged and the movable plate 502 moves upward, causing the first moving contact 24 and the first stationary contact 26 to disconnect, the power supply to the actuator can still be maintained. When the ash is almost completely discharged, the movable plate 502 moves to the highest position under the action of the elastic element 20, causing the second moving contact 25 and the second stationary contact 27 to make electrical contact. The coil of the normally closed relay 30 is energized, causing the normally closed contact of the normally closed relay 30 to open, the actuator is de-energized, and the discharge of ash stops.

[0038] This embodiment can not only automatically control the actuator to start under the set state, but also keep the actuator open for a certain period of time and automatically shut it off after the ash and slag are discharged, which can more conveniently control the discharge of ash and slag.

[0039] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any indirect modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A pyrolysis and charcoal production device for sewage sludge driven by smoldering combustion, characterized in that, include: The smoldering combustion chamber is equipped with a feeder that can accommodate the conveying and storage of pyrolysis sludge, and the feeder exchanges heat with the smoldering combustion chamber. A nitrogen pipeline, connected to the feeder, provides an inert environment for the sludge pyrolysis reaction; The smoldering combustion chamber is equipped with smoldering sludge, which is in a smoldering state and heats the sludge to be pyrolyzed in the feeder to the pyrolysis temperature.

2. The smoldering-driven wastewater sludge pyrolysis charcoal production device according to claim 1, characterized in that, The top and bottom of the smoldering combustion chamber are respectively provided with a smoldering preheating chamber and a smoldering ash chamber; A first baffle plate is provided between the smoldering preheating chamber and the smoldering combustion chamber; A grate is provided between the smoldering combustion chamber and the smoldering ash chamber.

3. The smoldering-driven wastewater sludge pyrolysis charcoal production device according to claim 2, characterized in that, The side wall of the smoldering preheating chamber is connected to a flue gas duct, and the top of the feeder is provided with a flue gas branch pipe connected to the flue gas duct to allow the flue gas generated by pyrolysis to be discharged.

4. A smoldering-driven wastewater sludge pyrolysis charcoal production device according to claim 2 or 3, characterized in that, The ash chamber is equipped with a detection component for detecting the weight of accumulated ash. The bottom side of the ash chamber is connected to an ash discharge pipe, and the ash discharge pipe is equipped with an actuator for discharging ash.

5. The smoldering-driven wastewater sludge pyrolysis charcoal production device according to claim 4, characterized in that, The detection component includes: A fixing plate is located at the inner bottom of the smoldering ash chamber; The movable plate is vertically and movably connected to the fixed plate and is used to bear ash and slag; Several elastic elements are disposed between the fixed plate and the movable plate; As the amount of ash and slag carried on the movable plate increases, the elastic element is further compressed, causing the movable plate to move toward the fixed plate.

6. The smoldering-driven wastewater sludge pyrolysis charcoal production device according to claim 5, characterized in that, It also includes a triggering mechanism for triggering the actuator to open, comprising: The first moving contact is connected to the movable plate and moves synchronously with the movable plate; The first stationary contact is connected to the fixed plate and can be electrically connected to the first moving contact; The actuator is activated when the first moving contact makes electrical contact with the first stationary contact.

7. A smoldering-driven wastewater sludge pyrolysis charcoal production device according to claim 6, characterized in that, The fixed plate is provided with a column sleeve, and the movable plate is provided with a guide post that is slidably connected to the column sleeve. The first moving contact is located on the outer wall of the guide post, and the first stationary contact is located on the inner wall of the column sleeve.

8. A smoldering-driven wastewater sludge pyrolysis charcoal production device according to claim 7, characterized in that, The triggering mechanism further includes: The second moving contact and the second stationary contact are respectively located on the outer wall of the guide post and the inner wall of the post sleeve; A normally open relay is installed in the circuit between the power supply and the actuator. When the first moving contact makes electrical contact with the first stationary contact, the normally open relay is energized. A normally closed relay is connected in series with the normally open relay, and the normally closed relay is energized when the second moving contact is electrically connected to the second stationary contact; A holding relay, wherein the coil of the holding relay is connected in series with the normally open relay, and the normally open contact of the holding relay is connected in parallel with the normally open relay.

9. A smoldering-driven wastewater sludge pyrolysis charcoal production device according to claim 1, characterized in that, An air diffuser is provided at the bottom of the smoldering combustion chamber, including a coil located inside the smoldering combustion chamber and a connecting pipe connected to the coil. The coil is provided with several air inlets.

10. A smoldering-driven wastewater sludge pyrolysis charcoal production device according to claim 1, characterized in that, The wall of the smoldering combustion chamber is provided with a heat insulation protective layer.

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