Multi-source dust collaborative management composite fertilizer production line

Abstract

The application provides a multi-source dust collaborative treatment composite fertilizer production line, and belongs to the technical field of composite fertilizer production. The production line comprises an elevator, a belt conveyor, a granulating device, a screening device and a crushing device. The production line further comprises a first dust suction pipeline and a second dust suction pipeline. The first dust suction pipeline is provided with a first dust suction port and a second dust suction port. The first dust suction port is arranged at a material receiving end of the belt conveyor. The second dust suction port is arranged above a feeding port of the granulating device. The second dust suction pipeline is provided with a third dust suction port and a fourth dust suction port. The third dust suction port is in communication with an inner cavity of the granulating device. The fourth dust suction port is arranged above a feeding port of the crushing device. The first dust suction pipeline and the second dust suction pipeline are not in communication and are respectively connected with suction equipment. The first dust suction pipeline and the second dust suction pipeline are collaborative, thereby achieving collaborative dust removal for multiple dust generation points in the production line.

Description

Technical Field

[0001] This application relates to the field of compound fertilizer production technology, specifically to a compound fertilizer production line for synergistic treatment of multi-source dust. Background Technology

[0002] The production of compound fertilizer requires processing raw materials into compound fertilizer products through a production line. A compound fertilizer production line typically includes an elevator that lifts the raw materials upwards. The elevator has a feed inlet at the bottom and a discharge outlet at the top. The feed inlet is usually located in a pit, and a belt conveyor is installed at the discharge outlet. The elevator lifts and transports the raw materials from the pit to the belt conveyor, which then carries the raw materials downstream. Downstream of the belt conveyor, there is usually a granulation cylinder, a vibrating screen, and a crushing device. The raw materials are granulated into granules within the granulation cylinder. The product exiting the granulation cylinder is then screened by the vibrating screen. Larger particles and lumps are returned to the crushing device for further crushing.

[0003] There are usually differences in height and wind pressure at the connection points between adjacent pieces of equipment in a compound fertilizer production line. For example, wind pressure is generated at the discharge port of a bucket elevator due to the dropping and rotation of the buckets. Since the raw materials fall onto the belt conveyor, dust will be scattered at the connection point between the elevator and the belt conveyor. The scattered dust affects the workshop environment and the health of the workers. Therefore, dust control design is required for the compound fertilizer production line. Utility Model Content

[0004] This application provides a compound fertilizer production line for the synergistic treatment of multi-source dust, which is used to solve the technical problem that compound fertilizer production lines are prone to dust dispersion.

[0005] This application provides a multi-source dust synergistic treatment compound fertilizer production line, comprising: An elevator having a feed inlet at a lower end and a discharge outlet at an upper end; The belt conveyor has a receiving end at one end and a discharging end at the other end. The receiving end is located at the discharge port of the elevator and is used to receive the material output from the discharge port. The granulation device has a feed inlet for raw materials to enter its internal cavity, and the feed inlet of the granulation device is located below the discharge end; A screening device is used to screen the granules produced by the granulation device. A crushing device for crushing the particles screened out by the screening device, the crushing device having a feed inlet for the particles to enter its working chamber; In addition, the multi-source dust synergistic treatment compound fertilizer production line also includes a first dust suction pipe and a second dust suction pipe. The first dust suction pipe is provided with a first dust suction port and a second dust suction port. The first dust suction port is located at the receiving end of the belt conveyor, and the second dust suction port is located above the feed inlet of the granulation device. The second dust suction pipe is provided with a third dust suction port and a fourth dust suction port. The third dust suction port is connected to the inner cavity of the granulation device, and the fourth dust suction port is located above the feed inlet of the crushing device. The first dust suction pipe and the second dust suction pipe are not connected and are respectively connected to suction equipment.

[0006] In one embodiment, along the flow path of the airflow in the first suction pipe, the distance between the first suction port and the suction device connected to the first suction pipe is less than the distance between the second suction port and the suction device. The first suction port is connected to a first suction hood, which covers the receiving end. A dustproof plate is provided above the feed inlet of the granulation device, and the dustproof plate is spaced apart from the feed inlet of the granulation device. One end of the first suction pipe with the second suction port passes through the dustproof plate.

[0007] In one embodiment, the first dust collection hood includes a guide structure and a hood body. The hood body includes a top wall disposed above the belt conveyor, and a first side wall and a second side wall located on both sides of the belt conveyor. The hood body also includes a front side wall and a rear side wall disposed along the conveying direction of the belt conveyor. The guide structure guides the material output from the discharge port to the belt conveyor. The first dust collection port communicates with the inner cavity of the hood body. The guide structure is located on the rear side of the hood body opposite to the unloading end and communicates with the inner cavity of the hood body.

[0008] In one embodiment, the belt conveyor further includes a dust cover disposed above its conveyor belt, the dust cover being located in front of the first dust hood and abutting against the front sidewall of the first dust hood.

[0009] In one embodiment, a chute for guiding materials is provided between the discharge end and the feed inlet of the granulation device.

[0010] In one embodiment, the first suction pipe includes a first main pipe and branch pipes. The diameter of the first main pipe is larger than the diameter of the branch pipes. One end of the first main pipe has a main suction port, and the first suction pipe is connected to a corresponding suction device through the first main pipe. The first suction port and the second suction port are located in the branch pipes.

[0011] In one embodiment, the granulation device includes a housing and a roller disposed within the housing. Along the rotation axis of the roller, one end of the housing is provided with an observation window for observing the interior of the granulation device, and along the rotation axis, the third dust suction port is close to the observation window and away from the other end of the housing.

[0012] In one embodiment, a second dust suction hood is provided at the fourth dust suction port, the second dust suction hood covers the feed port of the crushing device, and the second dust suction hood is detachable and movable relative to the feed port of the crushing device.

[0013] In one embodiment, the second suction pipe includes a second main pipe and a free pipe section. The second main pipe is used for fixed installation at a target location. The third suction port is disposed on the second main pipe. The second suction pipe is connected to a corresponding suction device through the second main pipe. The fourth suction port is disposed on the free pipe section. One end of the free pipe section with the fourth suction port is installed on the second suction hood. The other end of the free pipe section is detachably connected to the second main pipe.

[0014] In one embodiment, the multi-source dust co-treatment compound fertilizer production line includes a drive motor that drives the elevator, and the drive motor is a variable speed motor.

[0015] According to the multi-source dust synergistic treatment compound fertilizer production line in the above embodiments, the first dust suction port in the first dust suction pipe can absorb the dust generated when the elevator unloads material to the belt conveyor, the second dust suction port can absorb the dust generated when the belt conveyor unloads material to the granulation device, the fourth dust suction port in the second dust suction pipe can absorb the dust at the crushed feed inlet, and the third dust suction port in the second dust suction pipe can absorb the dust and water vapor in the granulation device, which makes it easier for the staff to observe the material condition in the granulation device and can also reduce the dust discharge at the discharge port of the granulation device. This achieves dust control at multiple dust generation points in the compound fertilizer production line. Furthermore, the first dust suction pipe and the second dust suction pipe are relatively independent and are respectively connected to the suction equipment to ensure that the first dust suction pipe and the second dust suction pipe have reliable suction capabilities, thereby ensuring their reliable dust removal capabilities. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a compound fertilizer production line for synergistic treatment of multi-source dust in one embodiment of this application; Figure 2 This is a schematic diagram of the structure of the second dust collection hood in a compound fertilizer production line for multi-source dust synergistic treatment in one embodiment of this application.

[0017] List of feature names corresponding to the labels in the figure: 1. Elevator; 11. Elevator discharge port; 2. Belt conveyor; 21. Receiving end; 22. Discharge end; 23. Circular belt; 24. Dust cover; 3. Granulation device; 31. Granulation device inlet; 32. Outer shell; 321. Observation window; 4. Screening device; 5. Crushing device; 51. Crushing device feed inlet; 6. First suction pipe; 61. First suction port; 62. Second suction port; 63. First fan; 64. First main pipe; 65. Branch pipe; 66. Main suction port; 67. First suction hood; 671. Guide structure; 672. Hood body; 6721. Top wall; 6722. First side wall; 68. Dustproof plate; 69. Chute; 610. Mounting bracket; 7. Second suction pipe; 71. Third suction port; 72. Fourth suction port; 73. Second fan; 74. Second suction hood; 741. Bottom opening; 742. Side opening; 743. Top plate; 75. Second main pipe; 76. Free pipe section; 77. Connecting structure; 8. Drive motor. Detailed Implementation

[0018] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments. Similar elements in different embodiments are referred to by related similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of the present application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to the present application are not shown or described in the specification. This is to avoid obscuring the core parts of the present application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0019] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments, and the operational steps involved in each embodiment can also be rearranged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the specification and drawings are only for clearly describing a particular embodiment and do not imply that they represent the necessary components and / or order.

[0020] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages).

[0021] This application provides a compound fertilizer production line for synergistic treatment of multi-source dust, hereinafter referred to as the production line. Please refer to... Figure 1 The production line includes a hoist 1. At the compound fertilizer production site, the lower end of the hoist 1 is typically located in a pit, a deep pit excavated from the ground to store raw materials. The hoist 1 is capable of lifting the raw materials from the pit to a higher position.

[0022] In compound fertilizer production lines, the raw materials in the pit generally include chemical raw materials such as ammonium sulfate and potassium chloride. The raw material forms include powder and larger particles. The powder here is the powder that is generally recognized in this field. Under the influence of wind pressure and drop in the production line, the powder is relatively easy to disperse and form dust in the workshop.

[0023] like Figure 1 As shown, the elevator 1 has an upper discharge port 11 and a lower feed port. In some embodiments, the elevator 1 is a bucket elevator. The raw material in the pit enters the elevator 1 through the feed port and is lifted upward by the circulating buckets inside the elevator 1. When the material is above the discharge port 11, the buckets flip and dump the raw material, which then flows out through the discharge port 11. In other embodiments, the elevator 1 can also be in other forms, such as a screw conveyor. The specific structure of the elevator 1 is prior art and will not be described in detail here.

[0024] The production line also includes a belt conveyor 2, which consists of a frame and an annular belt 23 mounted on the frame. One end of the belt conveyor 2 is a receiving end 21, and the other end is a discharging end 22. The receiving end 21 is located below the discharge port 11 of the elevator. The raw material falls onto the annular belt 23 at the receiving end 21, is conveyed forward by the belt conveyor 2, and is finally unloaded at the discharging end 22.

[0025] To produce compound fertilizer granules, the production line also includes a granulation unit 3, such as... Figure 1 As shown, the granulation device 3 has a granulation device inlet 31, which is located below the discharge end 22 of the belt conveyor 2. This allows the raw material discharged from the discharge end 22 to fall into the granulation device inlet 31 and eventually enter the inner cavity of the granulation device 3. Inside the granulation device 3, the raw material, slurry, colorant, and water are mixed by rolling and are formed into product granules under the assistance of steam heating. The product granules are finally discharged through the outlet of the granulation device 3.

[0026] Downstream of granulation device 3, a drying device and a cooling device are also installed to dry and cool the product granules formed by granulation device 3. These two parts are also existing technology. Figure 1 This is not shown in the text and will not be elaborated upon here.

[0027] The granules produced by the granulation device 3 are mainly divided into three categories according to particle size: qualified-sized granules, oversized granules, and undersized granules. Oversized and undersized granules are considered unqualified products. Therefore, the cooled granules need to be sieved to remove the qualified-sized granules. Correspondingly, a screening device 4 is also provided in the production line to screen the granules. In some embodiments, the screening device 4 is a vibrating screen; in other embodiments, it can also be a drum screen.

[0028] For the oversized product particles screened out, they need to be crushed and granulated again. Therefore, the production line also includes a crushing device 5 set downstream of the screening device 4. The crushing device 5 has a crushing device inlet 51, which is set at the outlet of the screening device 4. The oversized product particles screened out enter the crushing device 5 through the crushing device inlet 51 and are crushed into powder. The powder formed by crushing finally enters the granulation device 3 and is granulated again.

[0029] To reduce dust generated in the workshop during production line operation, the production line also includes a dust collection system. Please refer to [link / reference needed]. Figure 1 The dust collection system includes a first dust collection pipe 6 and a second dust collection pipe 7. The dust collection system achieves dust control by suctioning dust under negative pressure.

[0030] The first dust extraction pipe 6 is equipped with a first dust extraction port 61 and a second dust extraction port 62. The first dust extraction port 61 is located at the receiving end 21 of the belt conveyor 2, and it extracts dust that is dispersed from the raw material falling from the elevator outlet 11 onto the belt conveyor 2, as well as dust raised by the wind at the elevator outlet 11. The second dust extraction port 62 is located above the feed inlet 31 of the granulation device, and it extracts dust generated by the falling raw material at that location.

[0031] The second dust extraction pipe 7 is equipped with a third dust extraction port 71 and a fourth dust extraction port 72. The third dust extraction port 71 is connected to the inner cavity of the granulation device 3 and is used to extract smoke and dust from the inner cavity of the granulation device 3, improving visibility and facilitating operators to observe the condition of the product particles inside the granulation device 3. The fourth dust extraction port 72 is located above the crushing device feed inlet 51 of the crushing device 5 to absorb the dust generated by the falling product particles there.

[0032] To ensure reliable suction capabilities of the first and second suction pipes 6 and 7, they are relatively independent and not interconnected. Furthermore, each of the first and second suction pipes 6 is connected to a suction device. In some embodiments, the suction device connected to the first suction pipe 6 is a first fan 63, and the suction device connected to the second suction pipe 7 is a second fan 73. Negative pressure suction is achieved through these suction devices. This enables the coordinated treatment of multi-source and multi-point dust in the production line. The airflow carrying dust within the first and second suction pipes 6 and 7 ultimately flows to the dust removal equipment for dust collection.

[0033] Regarding the structural form of the first suction pipe 6, in some embodiments, the first suction pipe 6 includes a first main pipe 64 and branch pipes 65. The diameter of the first main pipe 64 is larger than that of the branch pipes 65. Branch pipe 65 can be a 200mm diameter pipe. The first suction pipe 6 is connected to the first fan 63 through the first main pipe 64. One end of the first main pipe 64 has a main suction port 66, which is located at the pit to absorb dust from the pit. The first suction port 61 and the second suction port 62 are located on the branch pipes 65.

[0034] To prevent negative pressure dispersion and dust spillage, a first dust suction port 61 is connected to a first dust suction hood 67, which covers the receiving end 21 of the belt conveyor 2. In some embodiments, please refer to... Figure 1 The first dust collection hood 67 includes a guide structure 671 and a hood body 672. The hood body 672 includes a top wall 6721 disposed above the belt conveyor 2. The top wall 6721 and the annular belt 23 of the belt conveyor 2 are spaced apart in the vertical direction, and the width of the top wall 6721 in the horizontal direction is greater than that of the belt conveyor 2. The hood body 672 also includes a first side wall 6722 located on the right side of the belt conveyor 2, and a second side wall disposed on the left side of the belt conveyor 2 opposite to the first side wall 6722. The upper ends of the first side wall 6722 and the second side wall are connected to the top wall 6721. The first dust collection hood 67 is supported and installed on the ground by the first side wall 6722 and the second side wall. The cover 672 also includes a front sidewall and a rear sidewall arranged along the conveying direction of the belt conveyor 2. The front and rear sidewalls are both located between the first sidewall 6722 and the second sidewall, with their upper ends connected to the top wall 6721 and their lower ends facing and close to the annular belt 23 of the belt conveyor 2. The top wall 6721, the first sidewall 6722, the second sidewall, the front sidewall, and the rear sidewall form the inner cavity of the cover 672, and the first dust suction port 61 communicates with the inner cavity of the cover 672.

[0035] The guide structure 671 is a tubular structure, with one end connected to the discharge port 11 of the elevator and the other end connected to the inner cavity of the cover 672, guiding the raw material output from the discharge port 11 of the elevator to the belt conveyor 2. The left-right dimension of the guide structure 671 is smaller than the same-direction dimension of the cover 672. Regarding the positional relationship between the guide structure 671 and the cover 672, the guide structure 671 is located on the rear side of the cover 672 away from the unloading end 22. Specifically, an opening is provided on the rear side wall of the cover 672, and the lower end of the guide structure 671 faces the annular belt 23 while also communicating with the inner cavity of the cover 672 through the opening.

[0036] This configuration of the first dust collection hood 67, including the guide structure 671 and the hood body 672, eliminates the need for the entire elevator discharge port 11 to be completely covered within it, facilitating the arrangement of the first dust collection hood 67. Of course, in other embodiments, the first dust collection hood 67 can also have other structures that can cover both the elevator discharge port 11 and the receiving end 21 of the belt conveyor 2.

[0037] To reduce dust, please refer to Figure 1 The belt conveyor 2 also includes a dust cover 24 disposed above its conveyor belt, i.e., the annular belt 23. The dust cover 24 covers the frame of the belt conveyor 2 and is spaced a certain distance vertically from the annular belt 23 to cover the annular belt 23 and prevent dust from being generated during the transportation of raw materials. The dust cover 24 is located in front of the first dust suction hood 67 and abuts against the front side wall of the first dust suction hood 67.

[0038] When the first main pipe 64 is arranged in the workshop, it is usually set against the wall. Therefore, along the flow path of the airflow in the first dust suction pipe 6, the distance between each dust suction port on the branch pipe 65 and the first fan 63 will vary. In some embodiments, the distance between the first dust suction port 61 and the first fan 63 is less than the distance between the second dust suction port 62 and the first fan 63. To ensure that the second dust suction port 62 can effectively suck up the dust at the feed inlet 31 of the granulation device, only a dustproof plate 68 is provided above the feed inlet 31 of the granulation device, without a dust suction hood. The dustproof plate 68 is spaced apart from the feed inlet 31 of the granulation device. One end of the first dust suction pipe 6 with the second dust suction port 62 passes through the dustproof plate 68. The dustproof plate 68 can prevent dust from drifting upwards. At the same time, the lower side of the dustproof plate 68 is an open structure, which can reduce the resistance when the second dust suction port 62 sucks up. When there is a negative pressure in the branch pipe 65, under the action of the internal and external pressure difference, the outside air is more likely to carry the dust into the branch pipe 65 through the second dust suction port 62, ensuring that each dust suction port of the first dust suction pipe 6 has reliable dust suction capability.

[0039] In some embodiments, a chute 69 is provided between the discharge end 22 of the belt conveyor 2 and the feed inlet 31 of the granulation device to guide the material flow to the feed inlet 31 of the granulation device and reduce dust rising.

[0040] To better manage dust at the discharge port 11 of the elevator, in some embodiments, the production line is configured with a drive motor 8 that powers the elevator 1. The drive motor 8 is a variable speed motor. When the dust content in the raw material is high, the speed of the drive motor 8 can be reduced to decrease the discharge speed of the raw material. When the dust content in the raw material is low, the speed of the drive motor 8 can be increased to increase the feeding speed.

[0041] The granulation device 3 includes a housing 32. To achieve the granulation function, the granulation device 3 also includes a roller disposed within the housing 32. The roller's own axis is horizontally positioned and rotatably disposed within the housing 32 around its own axis. The housing 32 itself is also an elongated cylinder extending along the rotation axis of the roller. The structure and working principle of the granulation device 3 are prior art and will not be described in detail here. It should be noted that, in this application, along the roller axis, one end of the housing 32 of the granulation device 3 has an observation window 321. The observation window 321 is provided with a glass window and can be opened. The third dust suction port 71 is connected to the end of the housing 32 near the observation window 321 and away from the other end of the housing 32. This can minimize smoke and dust around the observation window 321, making it easier for operators to observe the internal conditions of the granulation device 3 to adjust the amount of slurry, pigment water, and steam, while also reducing the temperature at the front end of the granulation device 3 and improving the working environment.

[0042] In some embodiments, a second dust hood 74 is provided at the fourth dust inlet 72 to prevent dust from overflowing and to ensure suction power. The second dust hood 74 covers the feed inlet 51 of the crushing device, and the second dust hood 74 is detachable and movable relative to the feed inlet 51 of the crushing device, so that the second dust hood 74 can be removed before each start-up to check and clean the feed inlet 51 of the crushing device.

[0043] To facilitate the removal of the second dust collection hood 74, the second dust collection pipe 7 includes a second main pipe 75 and a free pipe section 76. The second main pipe 75 is used for fixed installation at the target location. A third dust collection port 71 is provided on the second main pipe 75. The second main pipe 75 includes a granulation air duct for sucking up dust from the inner cavity of the granulation device 3. The second dust collection pipe 7 is connected to the second fan 73 through the second main pipe 75. A fourth dust collection port 72 is provided at one end of the free pipe section 76, and the end of the free pipe section 76 with the fourth dust collection port 72 is installed on the second dust collection hood 74. The other end of the free pipe section 76 is detachably connected to the second main pipe 75, forming a connection structure 77 at the connection point. When it is necessary to move the second dust collection hood 74, the connection structure 77 can be disconnected, and the free pipe section 76 can then move along with the second dust collection hood 74. One possible method for the connection structure 77 is to wrap a rubber tape around the joint between the free pipe section 76 and the second main pipe 75 to achieve interface connection and sealing. The free pipe section 76 and the part of the second main pipeline 75 that connects to the free pipe section 76 can be pipes with a diameter of 200mm. The diameter of the pipe connecting the second main pipeline 75 to the granulation device 3 can be larger than the diameter of the free pipe section 76.

[0044] For the installation and layout of the production line in the factory workshop, one feasible method is to excavate a pit on the first floor of the factory, install the granulation device 3 on the second floor, dig a hole in the roof of the second floor, and place the granulation device inlet 31 in the hole in the roof of the second floor. The belt conveyor 2 is installed on the third floor of the factory, and the lower end of the elevator 1 is located at the pit on the first floor of the factory, while the upper end is located in the workshop on the third floor of the factory. The dustproof plate 68 is supported and installed on the floor of the third floor of the factory by the mounting frame 610. There is a floor slab between the screening device 4 and the crushing device 5, with the screening device 4 located above the floor slab and the crushing device 5 located below the floor slab. A hole is dug in the floor slab, through which the crushing device inlet 51 passes to reach the discharge chute (also the return port) of the screening device 4. A second dust suction hood 74 is placed on the floor slab, covering the crushing device inlet 51. The second dust suction hood 74 is not fixed to facilitate movement.

[0045] In some embodiments, please refer to Figure 2 The second dust collection hood 74 has a cubic box-shaped structure, with one side and the bottom being open, i.e., it has a bottom opening 741 and a side opening 742. The bottom opening 741 allows the second dust collection hood 74 to cover the feed inlet 51 of the crushing device, while the side opening 742 avoids the discharge chute of the screening device 4, facilitating the arrangement of the second dust collection hood 74. The free pipe section 76 is connected to the top plate 743 of the second dust collection hood 74.

[0046] By using this application to perform multi-source synergistic dust removal on the production line, the amount of dust in the workshop can be effectively reduced by 70%.

[0047] The above examples illustrate this application only to aid understanding and are not intended to limit its scope. Those skilled in the art to which this application pertains can make various simple deductions, modifications, or substitutions based on the ideas presented.

Claims

1. A compound fertilizer production line for synergistic treatment of multi-source dust, characterized in that, include: An elevator having a feed inlet at a lower end and a discharge outlet at an upper end; The belt conveyor has a receiving end at one end and a discharging end at the other end. The receiving end is located at the discharge port of the elevator and is used to receive the material output from the discharge port. The granulation device has a feed inlet for raw materials to enter its internal cavity, and the feed inlet of the granulation device is located below the discharge end; A screening device is used to screen the granules produced by the granulation device. A crushing device for crushing the particles screened out by the screening device, the crushing device having a feed inlet for the particles to enter its working chamber; In addition, the multi-source dust synergistic treatment compound fertilizer production line also includes a first dust suction pipe and a second dust suction pipe. The first dust suction pipe is provided with a first dust suction port and a second dust suction port. The first dust suction port is located at the receiving end of the belt conveyor, and the second dust suction port is located above the feed inlet of the granulation device. The second dust suction pipe is provided with a third dust suction port and a fourth dust suction port. The third dust suction port is connected to the inner cavity of the granulation device, and the fourth dust suction port is located above the feed inlet of the crushing device. The first dust suction pipe and the second dust suction pipe are not connected and are respectively connected to suction equipment.

2. The multi-source dust synergistic treatment compound fertilizer production line as described in claim 1, characterized in that, Along the flow path of the airflow in the first suction pipe, the distance between the first suction port and the suction device connected to the first suction pipe is less than the distance between the second suction port and the suction device. The first suction port is connected to a first suction hood, which covers the receiving end. A dustproof plate is provided above the feed inlet of the granulation device, and the dustproof plate is spaced apart from the feed inlet of the granulation device. One end of the first suction pipe with the second suction port passes through the dustproof plate.

3. The multi-source dust synergistic treatment compound fertilizer production line as described in claim 2, characterized in that, The first dust collection hood includes a guide structure and a hood body. The hood body includes a top wall disposed above the belt conveyor, and a first side wall and a second side wall located on both sides of the belt conveyor. The hood body also includes a front side wall and a rear side wall disposed along the conveying direction of the belt conveyor. The guide structure guides the material output from the discharge port to the belt conveyor. The first dust collection port communicates with the inner cavity of the hood body. The guide structure is located on the rear side of the hood body opposite to the unloading end and communicates with the inner cavity of the hood body.

4. The multi-source dust synergistic treatment compound fertilizer production line as described in claim 3, characterized in that, The belt conveyor also includes a dust cover disposed above its conveyor belt, the dust cover being located in front of the first dust hood and abutting against the front sidewall of the first dust hood.

5. The multi-source dust synergistic treatment compound fertilizer production line according to any one of claims 2-4, characterized in that, A chute for guiding materials is provided between the discharge end and the feed inlet of the granulation device.

6. The multi-source dust synergistic treatment compound fertilizer production line according to any one of claims 2-4, characterized in that, The first suction pipe includes a first main pipe and branch pipes. The diameter of the first main pipe is larger than the diameter of the branch pipes. One end of the first main pipe has a main suction port, and the first suction pipe is connected to a corresponding suction device through the first main pipe. The first suction port and the second suction port are located in the branch pipes.

7. The multi-source dust synergistic treatment compound fertilizer production line according to any one of claims 1-4, characterized in that, The granulation device includes a housing and a roller disposed inside the housing. Along the rotation axis of the roller, one end of the housing is provided with an observation window for observing the interior of the granulation device, and along the rotation axis, the third dust suction port is close to the observation window and away from the other end of the housing.

8. The multi-source dust synergistic treatment compound fertilizer production line according to any one of claims 1-4, characterized in that, A second dust suction hood is provided at the fourth dust suction port. The second dust suction hood covers the feed port of the crushing device and is detachable and movable relative to the feed port of the crushing device.

9. The multi-source dust synergistic treatment compound fertilizer production line as described in claim 8, characterized in that, The second suction pipe includes a second main pipe and a free pipe section. The second main pipe is used for fixed installation at the target location. The third suction port is provided on the second main pipe. The second suction pipe is connected to the corresponding suction device through the second main pipe. The fourth suction port is provided on the free pipe section. One end of the free pipe section with the fourth suction port is installed on the second suction hood. The other end of the free pipe section is detachably connected to the second main pipe.

10. The multi-source dust synergistic treatment compound fertilizer production line according to any one of claims 1-4, characterized in that, The multi-source dust synergistic treatment compound fertilizer production line includes a drive motor that drives the elevator, and the drive motor is a variable speed motor.

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