Fabricated equipment for preparing nitrogen fertilizer from sludge of town sewage plant and preparation process

Abstract

The invention discloses assembly type equipment for preparing nitrogen fertilizer from sludge of a town sewage plant. The assembly type equipment comprises a feeding assembly, a mixing and stirring assembly and a fermentation tank, and a first conveying assembly is arranged between the feeding assembly and the mixing and stirring assembly; a discharge port is formed in the bottom of the mixing and stirring assembly, a second conveying assembly is arranged at the bottom of the discharge port, and the output end of the second conveying assembly extends to the fermentation tank; a guide rail is arranged at the top of the fermentation tank, a second rack is arranged on the guide rail, and a cloth turning and throwing assembly is arranged on the second rack; the device adapts to the demand change of different scales and sites, is high in flexibility, can conveniently perform material distribution and turning operation on materials through the arranged material distribution and turning assembly, ensures that the materials can obtain sufficient oxygen supply in the fermentation process, promotes the activity of microorganisms and the fermentation efficiency, and improves the fermentation efficiency. And meanwhile, the condition that the materials are caked can be avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of sludge treatment, and in particular to an assembled device and a preparation process for preparing nitrogen fertilizer from sludge in a municipal sewage plant. Background Art

[0002] With the rapid growth of my country's population and the acceleration of urbanization, urban sewage treatment has developed rapidly, and with it the generation of urban sludge. Since urban sludge contains a large amount of organic matter, nitrogen, phosphorus and other nutrients, as well as harmful substances such as heavy metals, organic pollutants and pathogens, if it is not properly handled, it may cause great harm to the ecological environment and human health.

[0003] At present, my country's sludge treatment mostly adopts incineration, drying or sanitary landfill methods, but these methods not only have too high treatment costs, but also cause pollution to the environment. Since the sludge contains nutrients required for plant growth, it has a significant improvement effect on the physical, chemical and biological properties of the soil. Therefore, in the existing technology, the sludge is made into organic fertilizer by using urban sewage plant sludge as raw material and adding auxiliary materials and then composting and fermenting.

[0004] After searching, the invention patent with publication number CN110540437A discloses an organic fertilizer fermentation device, including: a frame, the frame includes a processing frame and a fermentation frame fixed thereto, the processing frame and the fermentation frame are both placed on the ground; a cutting mechanism, the cutting mechanism is arranged on the processing frame to cut the straw inside the processing frame. The invention occupies a small area and is convenient to place. The straw can be cut and processed, which reduces the labor of farmers and simplifies the entire fermentation step. The straw and livestock and poultry excrement can be stirred and processed by the stirring mechanism. Only a few farmers need to participate in the fermentation preparation of organic fertilizer, and the labor intensity of a few farmers is not high. The existence of the heating aeration mechanism can improve the preparation effect and efficiency of the beneficial fertilizer. At the same time, in the process of preparing organic fertilizer, the one-time output of the invention is less than the output of the fermentation tank, but the preparation efficiency is much higher than that of the fermentation tank. Although the device can achieve a certain organic fertilizer preparation effect, it still has certain shortcomings. The equipment adopts an integrated fixed structure, which is inconvenient to install, disassemble and transport, and is difficult to adapt to the changes in the needs of different scales and sites. Secondly, when the device is used, the fermented material is turned over by the stirring mechanism. Although it can achieve a certain turning effect, it is difficult to evenly turn over all the materials in the fermentation tank. Further, the material is prone to agglomeration during fermentation. It is difficult for the device to process the agglomerated material when it is used, so the device still has certain shortcomings. Summary of the invention

[0005] The purpose of the present invention is to solve the problems in the prior art that the organic fertilizer preparation device has poor flexibility, is difficult to achieve a good turning effect, and is inconvenient to handle agglomerated materials, and proposes an assembled equipment for preparing nitrogen fertilizer from sludge in urban sewage plants.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: An assembled equipment for preparing nitrogen fertilizer from sludge in a municipal sewage plant, comprising a feeding assembly, a mixing assembly and a fermentation tank, wherein the feeding assembly comprises a first frame, an upper hopper arranged inside the first frame and a screen assembly arranged inside the upper hopper, a receiving hopper is arranged inside the first frame and at the bottom of the upper hopper, and a spiral discharging assembly is arranged inside the receiving hopper; A first conveying assembly is provided between the feeding assembly and the mixing and stirring assembly for conveying the material in the receiving hopper to the mixing and stirring assembly for mixing; the mixing and stirring assembly comprises a tank body and a stirring component arranged inside the tank body, a discharge port is provided at the bottom of the mixing and stirring assembly, a second conveying assembly is provided at the bottom of the discharge port, and an output end of the second conveying assembly extends to the fermentation tank; A guide rail is provided on the top of the fermentation tank, a second frame is provided on the guide rail, a track wheel matching the guide rail is connected to the bottom of the second frame, and a material distribution and flipping assembly for distributing the mixed material and flipping the fermenting material is provided on the second frame; The cloth flipping assembly comprises a cloth component arranged on the inner side of the second frame, a flipping component arranged on the inner side of the second frame and located at both ends of the cloth component, and a driving assembly arranged on the top of the second frame.

[0007] As a preferred technical solution of the present application, the stirring component includes a driving member arranged outside the tank body and a stirring member arranged inside the tank body and connected to the driving member.

[0008] As a preferred technical solution of the present application, the stirring element includes a stirring paddle arranged inside the tank body and a spiral blade arranged inside the tank body, wherein the tank body discharge port is located in the middle of the bottom of the tank body, and the spiral blades are symmetrically arranged in two groups with opposite spiral directions along the tank body discharge port.

[0009] As a preferred technical solution of the present application, the material distribution component includes a storage hopper arranged on the inner side of the second frame, a discharge port is arranged at the bottom of the storage hopper, and a crushing component is also arranged inside the storage hopper.

[0010] As a preferred technical solution of the present application, the crushing component includes a transmission roller arranged inside the storage hopper and a crushing blade arranged on the outer wall of the transmission roller, wherein the output end of the transmission roller is connected to the driving assembly.

[0011] As a preferred technical solution of the present application, the flipping component includes a connecting frame arranged on the inner side of the second frame, a scraper conveyor belt arranged on the inner side of the connecting frame, and a hydraulic cylinder arranged between the connecting frame and the second frame for adjusting the angle of the scraper conveyor belt, wherein a drive roller is arranged at the end of the scraper conveyor belt, and the drive roller passes through the connecting frame and extends outward.

[0012] As a preferred technical solution of the present application, the driving assembly includes a driving motor arranged on the top of the second frame, a first transmission belt arranged between the driving motor and the driving roller, and a second transmission belt arranged between the driving roller and the transmission roller.

[0013] As a preferred technical solution of the present application, a mounting frame is provided on the side wall of the storage hopper, rake teeth are provided through the mounting frame, and an elastic member is provided between the rake teeth and the mounting frame.

[0014] As a preferred technical solution of the present application, the tank body and the storage hopper discharge port are both provided with control valves, and the outer wall of the upper hopper is provided with a slag discharge port that cooperates with the screen assembly.

[0015] The present invention also discloses a preparation process for nitrogen fertilizer from sludge in a municipal sewage plant, which specifically comprises the following steps: S1: The treated sewage sludge and the auxiliary materials for preparing nitrogen fertilizer are placed in two groups of upper hoppers respectively. Under the vibration of the vibrator inside the upper hopper, the screen assembly screens the agglomerated sludge or agglomerated auxiliary materials and discharges them through the set slag discharge port. The screened materials fall into the receiving hopper and are discharged from the receiving hopper through the spiral discharging assembly. The bottom of the receiving hopper is provided with a first discharging port corresponding to the first conveying assembly. The sludge and auxiliary materials discharged from the first discharging port are conveyed to the mixing and stirring assembly through the first conveying assembly. S2: The driving member is started to drive the stirring paddle connected to its output end to rotate, thereby stirring and mixing the sludge and auxiliary materials entering the tank body. The spiral blades provided can turn the materials on both sides of the tank body toward the middle position to improve the mixing effect between the materials. Secondly, the two sets of spiral blades provided symmetrically can also conveniently discharge the mixed materials inside the tank body from the inside of the tank body for the convenience of the next operation; S3: The stirred and mixed materials are transported to the storage hopper in the material distribution component through the second conveying component. When the storage hopper is full, the track wheel is driven by the driving mechanism to move the storage hopper to the place where the materials are to be put in, and the valve of the storage hopper is opened to allow the materials inside to fall into the fermentation tank. Then, the storage hopper is driven back to the bottom of the output end of the second conveying component by the driving mechanism, and the above steps are repeated until the fermentation tank is filled. S4: After a period of fermentation, in order to provide sufficient oxygen inside the compost, prevent the material from being in an anaerobic state, and avoid excessive temperature of the pile body causing a large number of microorganisms to die or enter a dormant state, the material needs to be turned over so that it can better undergo aerobic fermentation. During the turning over, the cloth turning over assembly is controlled by the driving mechanism to move along the guide rail, and then the driving motor is started to drive the first transmission belt connected to its output end to rotate, thereby driving the driving roller to rotate, and then driving the scraper conveyor belt to rotate, turning over the material inside the fermentation tank so that it can better undergo aerobic fermentation; S5: When the drive motor is started to drive the scraper conveyor belt to flip and toss, the flipped materials will fall into the storage hopper. Further, when the drive motor is started, the second transmission belt configured in conjunction will drive the transmission roller to rotate, and then drive the crushing blades to rotate, thereby crushing the materials entering the storage hopper to prevent them from agglomerating during the fermentation process and affecting the fermentation effect. S6: The angle of the connecting frame can be adjusted by the hydraulic cylinder to make it suitable for turning over materials of different depths. At the same time, the angle of the turning over component can be adjusted to avoid affecting the cloth component. Furthermore, the rake teeth and elastic parts can flatten the material. Flattening can make the material ferment more evenly, avoid local overheating or overhumidification, and is conducive to the uniform distribution and activity of microorganisms. It can also increase the air permeability of the material, which is conducive to the entry of oxygen and the discharge of carbon dioxide, promote the reproduction and activity of aerobic microorganisms, and accelerate the decomposition of organic matter.

[0016] Compared with the prior art, the present invention provides an assembled equipment for preparing nitrogen fertilizer from sludge in urban sewage plants, which has the following beneficial effects: 1. The assembled equipment for preparing nitrogen fertilizer from sludge in urban sewage plants can be easily installed, disassembled and transported by adopting assembled equipment. It can also easily adapt to the changes in demand for different scales and sites, and has high flexibility. 2. The assembled equipment for preparing nitrogen fertilizer from sludge in urban sewage plants drives the second frame and the storage hopper to move along the fermentation tank through the provided cloth parts and the driving mechanism, and can conveniently and evenly transfer the mixed materials to the fermentation tank for fermentation operation; 3. The assembled equipment for preparing nitrogen fertilizer from sludge in urban sewage plants can effectively turn over the materials in the fermentation tank through the turning parts, ensuring that the materials can get sufficient oxygen supply during the fermentation process, and promoting the activity and fermentation efficiency of microorganisms; 4. The assembled equipment for preparing nitrogen fertilizer from sludge in urban sewage plants is equipped with a storage hopper and a crushing component inside the storage hopper. The storage hopper is set between two sets of flipping components. When flipping, the material will first fall into the storage hopper, and then the crushing component can be used to crush the material, avoiding agglomeration and affecting the fermentation effect. 5. The assembled equipment for preparing nitrogen fertilizer from sludge in urban sewage treatment plants can flatten the materials through the rake teeth and elastic parts. Flattening can make the fermentation of materials more uniform, avoid local overheating or overhumidification, and is conducive to the uniform distribution and activity of microorganisms. It can also increase the air permeability of materials, facilitate the entry of oxygen and the discharge of carbon dioxide, promote the reproduction and activity of aerobic microorganisms, and accelerate the decomposition of organic matter, thereby improving the preparation efficiency of organic fertilizers. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the structure of an assembled device for preparing nitrogen fertilizer from sludge in a municipal sewage plant proposed by the present invention Figure 1 ; Figure 2 This is a front view of an assembled device for preparing nitrogen fertilizer from sludge in a municipal sewage plant proposed by the present invention; Figure 3 A schematic diagram of the structure of an assembled device for preparing nitrogen fertilizer from sludge in a municipal sewage plant proposed by the present invention Figure 2 ; Figure 4 A top view of an assembled device for preparing nitrogen fertilizer from sludge in a municipal sewage plant proposed by the present invention; Figure 5 This is a schematic diagram of the structure of the cloth turning assembly in the assembled equipment for preparing nitrogen fertilizer from sludge in urban sewage plants proposed by the present invention. Figure 1 ; Figure 6 A bottom view of a cloth turning assembly in an assembled device for preparing nitrogen fertilizer from sludge in a municipal sewage plant proposed by the present invention; Figure 7 This is a front view of a cloth turning assembly in an assembled device for preparing nitrogen fertilizer from sludge in a municipal sewage plant proposed by the present invention; Figure 8 This is a schematic diagram of the structure of the cloth turning assembly in the assembled equipment for preparing nitrogen fertilizer from sludge in urban sewage plants proposed by the present invention. Figure 2 ; Fig. 9 The present invention proposes an assembled equipment for preparing nitrogen fertilizer from sludge in urban sewage plants Figure 8 Structural diagram of part A.

[0018] In the figure: 100, feeding assembly; 101, first frame; 102, upper hopper; 103, slag discharge port; 104, receiving hopper; 105, spiral discharge assembly; 200, mixing and stirring assembly; 201, tank; 202, stirring component; 203, discharge port; 204, driving member; 205, stirring member; 206, stirring paddle; 207, spiral blade; 300, fermentation tank; 301, guide rail; 302, second frame; 303, track wheel; 400, screen assembly; 500, first conveying assembly; 600, second conveying assembly Parts; 700, material distribution and flipping assembly; 701, material distribution parts; 7011, storage hopper; 7012, discharge port; 7013, crushing parts; 7014, transmission roller; 7015, crushing blades; 702, flipping assembly; 7021, connecting frame; 7022, scraper conveyor belt; 7023, hydraulic cylinder; 7024, driving roller; 703, driving assembly; 7031, driving motor; 7032, first transmission belt; 7033, second transmission belt; 704, mounting frame; 7041, rake teeth; 7042, elastic parts. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention. Example

[0020] Reference Figure 1-6 , an assembled equipment for preparing nitrogen fertilizer from sludge in urban sewage plants, comprising a feeding component 100, a mixing component 200 and a fermentation tank 300, The feeding assembly 100 includes a first frame 101, an upper hopper 102 arranged inside the first frame 101, and a screen assembly 400 arranged inside the upper hopper 102. A receiving hopper 104 is arranged inside the first frame 101 and at the bottom of the upper hopper 102. A spiral discharge assembly 105 is arranged inside the receiving hopper 104. The upper hopper 102 and the receiving hopper 104 can be respectively provided with two groups to screen the sludge and the auxiliary materials respectively. The screened materials fall into the receiving hopper 104 and are discharged through the spiral discharge assembly 105. A first conveying assembly 500 is provided between the feeding assembly 100 and the mixing and stirring assembly 200 for conveying the material in the receiving hopper 104 to the mixing and stirring assembly 200 for mixing; the mixing and stirring assembly 200 includes a tank body 201 and a stirring component 202 arranged inside the tank body 201, a discharge port 203 is provided at the bottom of the mixing and stirring assembly 200, a second conveying assembly 600 is provided at the bottom of the discharge port 203, and an output end of the second conveying assembly 600 extends to the fermentation tank 300, wherein the first conveying assembly 500 adopts a screw feeder, and the second conveying assembly 600 adopts a scraper feeder structure, which are all existing mature technologies and will not be described in detail here; A guide rail 301 is provided on the top of the fermentation tank 300, a second frame 302 is provided on the guide rail 301, a track wheel 303 matching the guide rail 301 is connected to the bottom of the second frame 302, and a material distribution and flipping assembly 700 for distributing the mixed material and flipping the fermenting material is provided on the second frame 302. By providing the material distribution and flipping assembly 700, the mixed material can be evenly transported to the inside of the fermentation tank 300, and flipped during the fermentation process to improve the aerobic fermentation effect; The cloth flipping assembly 700 includes a cloth component 701 arranged on the inner side of the second frame 302 , flipping components 702 arranged on the inner side of the second frame 302 and located at both ends of the cloth component 701 , and a driving assembly 703 arranged on the top of the second frame 302 .

[0021] Reference Figure 1-4 The stirring member 202 includes a driving member 204 disposed outside the tank body 201 and a stirring member 205 disposed inside the tank body 201 and connected to the driving member 204. The driving member 204 is a stirring motor, wherein the stirring members 205 are provided in a plurality of groups and are connected to each other by belts.

[0022] The stirring element 205 includes a stirring paddle 206 arranged inside the tank body 201 and a spiral blade 207 arranged inside the tank body 201, wherein the tank body discharge port 203 is located in the middle of the bottom of the tank body 201, and the spiral blade 207 is symmetrically arranged with two groups of spiral blades with opposite spiral directions along the tank body discharge port 203. The stirring paddle 206 and the spiral blade 207 are driven to rotate by the set driving component 703, so that the material inside the tank body 201 can be stirred and mixed. Furthermore, since the spiral blade 207 is symmetrically arranged with two groups of spiral blades with opposite spiral directions along the tank body discharge port 203, when it rotates, it can flip the two ends of the tank body 201 toward the middle position, thereby improving the mixing effect of the material.

[0023] Reference Figure 1 , Figure 5-Figure 9The distribution component 701 includes a storage hopper 7011 arranged on the inner side of the second frame 302, a discharge port 7012 is arranged at the bottom of the storage hopper 7011, and a crushing component 7013 is also arranged inside the storage hopper 7011. The material flipped by the flipping component 702 will fall into the storage hopper 7011 and will be crushed by the crushing component 7013 to avoid agglomeration and affect the fermentation effect.

[0024] The crushing component 7013 includes a transmission roller 7014 arranged inside the storage hopper 7011 and a crushing blade 7015 arranged on the outer wall of the transmission roller 7014, wherein the output end of the transmission roller 7014 is connected to the driving component 703, and the driving component 703 drives the transmission roller 7014 to rotate and then drives the crushing blade 7015 to rotate, so as to crush and disperse the material entering the storage hopper 7011 to avoid agglomeration.

[0025] Reference Figure 5-9 The flipping component 702 includes a connecting frame 7021 arranged on the inner side of the second frame 302, a scraper conveyor belt 7022 arranged on the inner side of the connecting frame 7021, and a hydraulic cylinder 7023 arranged between the connecting frame 7021 and the second frame 302 for adjusting the angle of the scraper conveyor belt 7022, wherein a driving roller 7024 is arranged at the end of the scraper conveyor belt 7022, and the driving roller 7024 passes through the connecting frame 7021 and extends outward.

[0026] Reference Figure 3 , Figure 5 , Figure 7 and Fig. 9 The driving assembly 703 includes a driving motor 7031 arranged on the top of the second frame 302, a first transmission belt 7032 arranged between the driving motor 7031 and the driving roller 7024, and a second transmission belt 7033 arranged between the driving roller 7024 and the transmission roller 7014. The driving motor 7031 is started to drive the first transmission belt 7032 connected to its output end to rotate, thereby driving the driving roller 7024 to rotate, and the second transmission belt 7033 arranged in cooperation drives the transmission roller 7014 to rotate, thereby realizing the operation of the crushing component 7013 and the flipping assembly 702.

[0027] Reference Figure 7-9 A mounting frame 704 is provided on the side wall of the storage hopper 7011, and rake teeth 7041 are provided through the mounting frame 704. An elastic member 7042 is provided between the rake teeth 7041 and the mounting frame 704. The rake teeth 7041 can have a certain flattening effect on the material.

[0028] Reference Figure 1-3The tank body 201 and the storage hopper 7011 are both provided with control valves at their discharge ports, and the upper hopper 102 is provided with a slag discharge port 103 on its outer wall that matches the screen assembly 400. The control valve is provided to facilitate control of the discharge of materials, and the slag discharge port 103 is provided to facilitate discharge of the screened materials.

[0029] Specifically, when the assembled equipment for preparing nitrogen fertilizer from sludge in urban sewage treatment plants is used: first, the treated sewage treatment plant sludge and the auxiliary materials for preparing nitrogen fertilizer are respectively placed in two groups of upper hoppers 102, and under the vibration of the vibrator inside the upper hopper 102, the screen assembly 400 screens the agglomerated sludge or agglomerated auxiliary materials, and discharges them through the provided slag discharge port 103, and the screened materials fall into the receiving hopper 104, and are discharged from the receiving hopper 104 through the spiral discharging assembly 105. The bottom of the receiving hopper 104 is provided with a first discharge port corresponding to the first conveying assembly 500, and the sludge and auxiliary materials discharged from the first discharge port are conveyed to the inside of the mixing and stirring assembly 200 through the first conveying assembly 500; The driving member 204 is started to drive the stirring paddle 206 connected to its output end to rotate, thereby stirring and mixing the sludge and auxiliary materials entering the tank body 201. The spiral blades 207 provided in combination can turn the materials located on both sides of the tank body 201 toward the middle position to improve the mixing effect between the materials. Secondly, the two sets of spiral blades 207 provided symmetrically can also conveniently discharge the mixed materials in the tank body 201 from the tank body 201 to facilitate the next operation. The stirred and mixed materials are transported to the storage hopper 7011 in the cloth component 701 through the second conveying component 600. When the storage hopper 7011 is full, the track wheel 303 is driven by the driving mechanism to move, and the storage hopper 7011 is moved to the place where the materials are to be put in. The valve of the storage hopper 7011 is opened to allow the materials inside to fall into the fermentation tank 300. Then, the storage hopper 7011 is driven by the driving mechanism to return to the bottom of the output end of the second conveying component 600, and the above steps are repeated until the fermentation tank 300 is filled. After a period of fermentation, in order to provide sufficient oxygen inside the compost, prevent the material from being in an anaerobic state, and avoid excessive temperature of the pile body causing a large number of microorganisms to die or enter a dormant state, the material needs to be turned over so that it can better undergo aerobic fermentation. When turning over, the cloth turning component 700 is controlled by the driving mechanism to move along the guide rail 301, and then the driving motor 7031 is started to drive the first transmission belt 7032 connected to its output end to rotate, thereby driving the driving roller 7024 to rotate, and then driving the scraper conveyor belt 7022 to rotate, turning over the material inside the fermentation tank 300, so that it can be better aerobically fermented. Furthermore, an aeration pipe can be laid at the bottom of the fermentation tank 300 to circulate aeration and oxygenate the material pile, thereby further improving the aerobic fermentation effect; When the drive motor 7031 is started to drive the scraper conveyor belt 7022 to flip, the flipped materials will fall into the storage hopper 7011. Further, when the drive motor 7031 is started, the second transmission belt 7033 provided in conjunction with it will drive the transmission roller 7014 to rotate, and then drive the crushing blade 7015 to rotate, so as to crush the materials entering the storage hopper 7011, so as to avoid agglomeration during the fermentation process and affect the fermentation effect. The hydraulic cylinder 7023 can be used to adjust the angle of the connecting frame 7021 to make it suitable for turning over materials of different depths. At the same time, the angle of the turning over component 702 can be adjusted to avoid affecting the cloth component 701. Furthermore, the rake teeth 7041 and the elastic member 7042 can be used to flatten the material. Flattening can make the material ferment more evenly, avoid local overheating or overhumidification, and is conducive to the uniform distribution and activity of microorganisms. It can also increase the air permeability of the material, which is conducive to the entry of oxygen and the discharge of carbon dioxide, promote the reproduction and activity of aerobic microorganisms, and accelerate the decomposition of organic matter.

[0030] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An assembled device for preparing nitrogen fertilizer from sludge in a municipal sewage plant, comprising a feeding component (100), a mixing and stirring component (200) and a fermentation tank (300), characterized in that: The feeding assembly (100) comprises a first frame (101), an upper hopper (102) arranged inside the first frame (101), and a screen assembly (400) arranged inside the upper hopper (102); a receiving hopper (104) is arranged inside the first frame (101) and at the bottom of the upper hopper (102); a spiral discharging assembly (105) is arranged inside the receiving hopper (104); A first conveying assembly (500) is arranged between the feeding assembly (100) and the mixing and stirring assembly (200) for conveying materials in the receiving hopper (104) to the mixing and stirring assembly (200) for mixing; the mixing and stirring assembly (200) comprises a tank body (201) and a stirring component (202) arranged inside the tank body (201); a discharge port (203) is arranged at the bottom of the mixing and stirring assembly (200); a second conveying assembly (600) is arranged at the bottom of the discharge port (203); an output end of the second conveying assembly (600) extends to the fermentation tank (300); A guide rail (301) is arranged on the top of the fermentation tank (300), a second frame (302) is arranged on the guide rail (301), a track wheel (303) matching the guide rail (301) is connected to the bottom of the second frame (302), and a material distribution and flipping assembly (700) for distributing mixed materials and flipping materials during fermentation is arranged on the second frame (302); The cloth flipping assembly (700) comprises a cloth component (701) arranged inside the second frame (302), flipping components (702) arranged inside the second frame (302) and located at both ends of the cloth component (701), and a driving assembly (703) arranged on the top of the second frame (302).

2. The assembled equipment for preparing nitrogen fertilizer from sludge in urban sewage treatment plants according to claim 1, characterized in that: The stirring component (202) comprises a driving component (204) arranged outside the tank body (201) and a stirring component (205) arranged inside the tank body (201) and connected to the driving component (204).

3. The assembled equipment for preparing nitrogen fertilizer from sludge in urban sewage treatment plants according to claim 2, characterized in that: The stirring member (205) comprises a stirring paddle (206) arranged inside the tank body (201) and a spiral blade (207) arranged inside the tank body (201), wherein the tank body discharge port (203) is located in the middle of the bottom of the tank body (201), and the spiral blade (207) is symmetrically arranged in two groups with opposite spiral directions along the tank body discharge port (203).

4. The assembled equipment for preparing nitrogen fertilizer from sludge in urban sewage treatment plants according to claim 1, characterized in that: The material distribution component (701) comprises a storage hopper (7011) arranged inside the second frame (302), a discharge port (7012) is arranged at the bottom of the storage hopper (7011), and a crushing component (7013) is also arranged inside the storage hopper (7011).

5. The assembled equipment for preparing nitrogen fertilizer from sludge in urban sewage treatment plants according to claim 4, characterized in that: The crushing component (7013) comprises a driving roller (7014) arranged inside the storage hopper (7011) and a crushing blade (7015) arranged on the outer wall of the driving roller (7014), wherein the output end of the driving roller (7014) is connected to the driving component (703).

6. An assembled equipment for preparing nitrogen fertilizer from sludge in urban sewage treatment plants according to claim 5, characterized in that: The tipping component (702) comprises a connecting frame (7021) arranged on the inner side of the second frame (302), a scraper conveyor belt (7022) arranged on the inner side of the connecting frame (7021), and a hydraulic cylinder (7023) arranged between the connecting frame (7021) and the second frame (302) for adjusting the angle of the scraper conveyor belt (7022), wherein a driving roller (7024) is arranged at the end of the scraper conveyor belt (7022), and the driving roller (7024) passes through the connecting frame (7021) and extends outward.

7. The assembled equipment for preparing nitrogen fertilizer from sludge in urban sewage treatment plants according to claim 6, characterized in that: The driving assembly (703) comprises a driving motor (7031) arranged on the top of the second frame (302), a first transmission belt (7032) arranged between the driving motor (7031) and the driving roller (7024), and a second transmission belt (7033) arranged between the driving roller (7024) and the transmission roller (7014).

8. The assembled equipment for preparing nitrogen fertilizer from sludge in urban sewage treatment plants according to claim 7, characterized in that: A mounting frame (704) is provided on the side wall of the storage hopper (7011), rake teeth (7041) are provided through the mounting frame (704), and an elastic member (7042) is provided between the rake teeth (7041) and the mounting frame (704).

9. The assembled equipment for preparing nitrogen fertilizer from sludge in urban sewage treatment plants according to claim 5, characterized in that: The tank body (201) and the material storage hopper (7011) are both provided with control valves at their discharge ports, and the outer wall of the upper hopper (102) is provided with a slag discharge port (103) that matches the screen assembly (400).

10. A process for preparing nitrogen fertilizer from sludge in urban sewage treatment plants, comprising the assembled equipment for preparing nitrogen fertilizer from sludge in urban sewage treatment plants according to any one of claims 1 to 9, characterized in that: The specific steps include: S1: The treated sewage treatment plant sludge and the auxiliary materials for preparing nitrogen fertilizer are placed in two groups of upper hoppers (102) respectively. Under the vibration of the vibrator inside the upper hopper (102), the screen assembly (400) screens the agglomerated sludge or agglomerated auxiliary materials and discharges them through the provided slag discharge port (103). The screened materials fall into the receiving hopper (104) and are discharged from the receiving hopper (104) through the spiral discharge assembly (105). The bottom of the receiving hopper (104) is provided with a first discharge port corresponding to the first conveying assembly (500). The sludge and auxiliary materials discharged from the first discharge port are conveyed to the inside of the mixing and stirring assembly (200) through the first conveying assembly (500); S2: starting the driving member (204) to drive the stirring paddle (206) connected to its output end to rotate, thereby stirring and mixing the sludge and auxiliary materials entering the tank body (201); the spiral blades (207) are arranged to turn the materials located on both sides of the tank body (201) toward the middle position to improve the mixing effect between the materials; secondly, the two sets of spiral blades (207) are arranged symmetrically to conveniently discharge the mixed materials inside the tank body (201) from the tank body (201) to facilitate the next operation; S3: The stirred and mixed materials are transported to the storage hopper (7011) in the material distribution component (701) through the second conveying component (600). When the storage hopper (7011) is full, the track wheel (303) is driven by the driving mechanism to move, and the storage hopper (7011) is moved to the location where the materials are to be put in. The valve of the storage hopper (7011) is opened to allow the materials inside to fall into the fermentation tank (300). The storage hopper (7011) is then driven by the driving mechanism to return to the bottom of the output end of the second conveying component (600), and the above steps are repeated until the fermentation tank (300) is filled. S4: After a period of fermentation, in order to provide sufficient oxygen inside the compost, prevent the material from being in an anaerobic state, and avoid excessive temperature of the compost body causing a large number of microorganisms to die or enter a dormant state, the material needs to be turned over so that it can better undergo aerobic fermentation. When turning over, the cloth turning component (700) is controlled by a driving mechanism to move along the guide rail (301), and then the driving motor (7031) is started to drive the first transmission belt (7032) connected to its output end to rotate, thereby driving the driving roller (7024) to rotate, and then driving the scraper conveyor belt (7022) to rotate, turning over the material inside the fermentation tank (300) so that it can better undergo aerobic fermentation; S5: When the driving motor (7031) is started to drive the scraper conveyor belt (7022) to flip and toss, the flipped material will fall into the storage hopper (7011). Further, when the driving motor (7031) is started, the second transmission belt (7033) provided in conjunction with it will drive the transmission roller (7014) to rotate, thereby driving the crushing blade (7015) to rotate, thereby crushing the material entering the storage hopper (7011) to prevent the material from agglomerating during the fermentation process and affecting the fermentation effect. S6: The angle of the connecting frame (7021) can be adjusted by the hydraulic cylinder (7023) to make it suitable for turning over materials of different depths. At the same time, the angle of the turning over component (702) can be adjusted to avoid affecting the cloth component (701). Furthermore, the rake teeth (7041) and the elastic member (7042) can be used to flatten the materials. Flattening can make the fermentation of the materials more uniform, avoid local overheating or overhumidification, and be beneficial to the uniform distribution and activity of microorganisms. It can also increase the air permeability of the materials, facilitate the entry of oxygen and the discharge of carbon dioxide, promote the reproduction and activity of aerobic microorganisms, and accelerate the decomposition rate of organic matter.

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