A dust collection system for a diammonium phosphate plant

Abstract

The utility model discloses a dust collecting system for diammonium phosphate device belongs to diammonium phosphate production dust recovery technical field, including cyclone dust collector, air hammer, lock gas star type feeder, plug valve, screw conveyer, buried scraper conveyer, feed chute and granulator, the utility model discloses rigid seal is realized to pneumatic double -deck plug valve, and lock gas star type feeder is additionally arranged before plug valve entrance, forms double lock gas sealing mechanism, and effectively prevents the air leakage and dust leakage in the process of unloading ash. Through the cooperation of screw conveyer and buried scraper conveyer, the full sealing and continuous conveying of dust from the dust collector to the granulator are realized, and the open return belt and bucket elevator are completely cancelled. The air hammer is installed at the bottom of the dust collector, and the dust is prevented from accumulating and hardening in the dust collector hopper by regular knocking. The rotating blade structure of the lock gas star type feeder also helps to prevent the bridging of materials at the plug valve inlet, and optimizes the system operating condition.

Description

Technical Field

[0001] This utility model relates to a dust collection system, and more particularly to a dust collection system for a diammonium phosphate plant, belonging to the field of dust recovery technology in diammonium phosphate production. Background Technology

[0002] The production of diammonium phosphate (DAP) requires a dust removal system, which is a crucial aspect of process safety and environmental compliance. During DAP production, DAP-containing dust is generated in processes such as granulation and screening. This dust can be collected by equipment like cyclone dust collectors and returned to the granulation process for direct reuse, reducing raw material loss and achieving dust recycling. Secondly, the dust removal system effectively controls the dust content in the exhaust gas, preventing environmental violations. Furthermore, dust accumulation can easily cause equipment blockage or corrosion (such as in pipes and fans), and high-concentration dust environments pose an explosion risk. The dust removal system maintains negative pressure operation, reducing on-site dust.

[0003] In the existing industrial production process of diammonium phosphate, cyclone separators are usually used to separate the exhaust gas carrying dust. The separated dust is usually recovered by cyclone dust collectors in conjunction with rubber valves or counterweight valves, return conveyor belts and granulation bucket elevators. The specific dust collection process of diammonium phosphate is as follows: the cyclone dust collector discharges the material with rubber valves or (counterweight valves), then the dust enters the return conveyor belt, then enters the granulation bucket elevator, and finally flows into the granulator.

[0004] The above process has the following defects: (1) poor sealing: the cyclone dust collector uses rubber valves (or counterweight valves), which are easily damaged, resulting in air and dust leakage. Dust enters the washing system and increases the load; (2) serious secondary dust: the dust needs to go through the return conveyor belt → bucket elevator → granulator, which is a long process with insufficient sealing. Repeated dust generation reduces the dust collection efficiency; (3) reliance on manual labor: when the valve fails or the dust collector is blocked, it needs to be cleaned manually frequently, resulting in low automation. Because diammonium phosphate is easily soluble in water and has a certain viscosity. When using a cyclone separator to separate gas and solid, the separated dust particles are easy to stick together and accumulate. After a certain period of time, the dust particles will slowly accumulate and block the cyclone separator channel. In mild cases, it reduces the dust removal effect of the cyclone separator, and in severe cases, it may even cause equipment accidents. Utility Model Content

[0005] In order to overcome the shortcomings of the prior art, this utility model provides a dust collection system for a diammonium phosphate plant.

[0006] The technical solution adopted in this utility model is as follows: a dust collection system for a diammonium phosphate plant is designed, including a cyclone dust collector and a granulator. The granulator is located at the ash discharge end of the cyclone dust collector to receive the dust separated by the cyclone dust collector and granulate it for recycling. It also includes an airlock rotary feeder and a gate valve. The airlock rotary feeder and gate valve are located at the ash discharge end of the cyclone dust collector. The dust separated by the cyclone dust collector passes through the airlock rotary feeder and gate valve sequentially before entering the granulator for granulation. The structure of the airlock rotary feeder combined with the gate valve achieves continuous sealed conveying of ash discharged from the cyclone dust collector, preventing secondary dust escape. Simultaneously, the gate valve can adjust the dust flow rate, ensuring the stability of the feed to the granulator.

[0007] Furthermore, this design also includes a submerged scraper conveyor and a feed chute. The submerged scraper conveyor is located between the granulator and the gate valve, and the feed chute is located between the feed end of the granulator and the discharge end of the submerged scraper conveyor. The dust output from the gate valve is conveyed by the submerged scraper conveyor to the feed chute and then enters the granulator. The submerged scraper conveyor evenly disperses the dust to the feed end of the granulator, avoiding local accumulation; the feed chute design reduces dust dispersion and improves granulation efficiency.

[0008] Furthermore, this design also includes a screw conveyor, which is positioned between the gate valve and the submerged scraper conveyor. The dust output from the gate valve is conveyed to the submerged scraper conveyor via the screw conveyor. The screw conveyor serves as an intermediate buffer section, balancing the flow rate difference between the gate valve and the submerged scraper conveyor to ensure continuous and stable dust transport. Furthermore, this design also includes an air hammer, which is located at the bottom of the cyclone dust collector and above the airlock star feeder. The air hammer periodically taps the bottom of the dust collector to prevent dust from accumulating and clogging, ensuring the continuous and efficient operation of the airlock star feeder.

[0009] Furthermore, the slide gate valve described in this design is a pneumatic double-layer slide gate valve. The double-layer valve structure enhances sealing performance, making it particularly suitable for high-humidity or moisture-absorbing diammonium phosphate dust, thus reducing the risk of leakage.

[0010] Furthermore, the cyclone dust collector, air hammer, airlock star feeder, pneumatic double-layer slide gate valve, and screw conveyor mechanism described in this design form a dust conveying line, with at least three of these dust conveying lines connected to the buried scraper conveyor. Each dust conveying line can operate independently or in coordination, facilitating system maintenance and fault isolation, and reducing downtime. The multi-line parallel design significantly increases dust handling capacity, adapting to the needs of large-scale diammonium phosphate production. The number of conveying lines in operation can be adjusted according to the actual dust generation, optimizing energy consumption and efficiency.

[0011] Furthermore, the buried scraper conveyor is connected to three dust conveying lines, with the discharge ends of the three lines respectively connected to the left, middle, and right ends of the buried scraper conveyor. Dust enters the buried scraper conveyor from multiple locations, avoiding equipment overload caused by single-point accumulation. The multi-end feeding design adapts to complex plant layouts and reduces interference from intersecting pipelines. Dispersed feeding reduces the risk of concentrated stress on the conveyor chain plates, extending equipment life.

[0012] Furthermore, each dust conveying line includes two cyclone dust collectors and one screw conveyor. The two cyclone dust collectors are arranged side by side and share one screw conveyor. Sharing the screw conveyor reduces the number of equipment, lowering investment costs and floor space. The parallel operation of the two dust collectors optimizes separation efficiency. In the event of a failure in one screw conveyor, the other can still maintain partial conveying capacity, ensuring system continuity.

[0013] Furthermore, each of the two cyclone dust collectors on each dust conveying line is equipped with an air hammer, an airlock star feeder, and a pneumatic double-layer slide gate valve at its bottom, with the output ends of the two pneumatic double-layer slide gate valves connected to the same screw conveyor. The independent configuration of air hammers and airlock devices for each dust collector prevents single-point blockages from affecting the entire line's operation. The convergence of the two slide gate valves to the same screw conveyor simplifies the subsequent conveying process and reduces the risk of dust leakage. Independent control of the ash discharge components of each dust collector facilitates targeted maintenance.

[0014] Furthermore, the screw conveyor is equipped with a feed pipe at its left end, and the output ends of the two pneumatic double-layer gate valves of each dust conveying line are connected to this feed pipe. This design is simple in structure, requires fewer pipes, reduces installation complexity and cost, and is suitable for scenarios with low dust flow rates. Alternatively, the screw conveyor may have feed pipes at its left end and middle section, with the output ends of the two gate valves of each dust conveying line connected to the two feed pipes respectively. This diversion design reduces the risk of single-pipe blockage and improves conveying reliability; it also adapts to high dust flow conditions and avoids overloading of the screw conveyor.

[0015] Compared with the prior art, the beneficial effects of this utility model are: This invention eliminates the easily damaged rubber valve in existing technologies, employing a pneumatic double-layer slide gate valve to achieve a rigid seal. An airlock star feeder is added before the slide gate valve inlet, forming a double airlock sealing mechanism to effectively prevent air and dust leakage during ash unloading. Through the cooperation of a screw conveyor and a submerged scraper conveyor, fully sealed and continuous dust transport from the dust collector to the granulator is achieved, completely eliminating open return belts and bucket elevators. An air hammer is installed at the bottom of the dust collector to periodically tap and prevent dust from accumulating and caking in the dust collector hopper; the rotating blade structure of the airlock star feeder also helps prevent material bridging at the slide gate valve inlet. The airlock star feeder ensures that the dust, loosened by the air hammer, enters the double-layer slide gate valve and subsequent conveying system evenly and stably, optimizing equipment operating conditions.

[0016] This invention relates to a system where dust, after being loosened by an air hammer, is stably fed by a star-shaped feeder, then sealed and discharged through a double-layer gate valve, and finally fed directly into the granulator via a fully enclosed screw conveyor and a submerged scraper conveyor, thus shortening the process to some extent. The intelligent linkage of multiple devices enables unmanned automatic dust discharge and conveying, reducing manual intervention and significantly lowering the risk of blockage. Through sealed conveying technology, this system significantly improves dust recovery rates and reduces equipment wear, meeting the environmental protection and high-efficiency production requirements of the diammonium phosphate industry. It achieves the goals of high processing capacity, low maintenance costs, and strong system stability, making it particularly suitable for dust recovery scenarios in diammonium phosphate production. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the system layout of this utility model.

[0019] Figure 2 This is a schematic diagram of the dust conveying line of this utility model.

[0020] In the diagram: 1. Cyclone dust collector; 2. Granulator; 3. Airlock star feeder; 4. Pneumatic double-layer slide gate valve; 5. Submerged scraper conveyor; 6. Screw conveyor; 7. Air hammer; 8. Dust conveying line; 9. Feed pipe. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0022] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0023] Example 1 like Figure 1-2 As shown, a dust collection system for a diammonium phosphate plant includes a cyclone dust collector 1, an air hammer 7, an airlock rotary feeder 3, a slide gate valve, a screw conveyor 6, a submerged scraper conveyor 5, a feed chute (not shown in the attached diagram), and a granulator 2. The granulator 2 is located at the ash discharge end of the cyclone dust collector 1 to receive the dust separated by the cyclone dust collector 1 and granulate it for recycling. The airlock rotary feeder 3 and the slide gate valve are located at the ash discharge end of the cyclone dust collector 1. The dust separated by the cyclone dust collector 1 passes through the airlock rotary feeder 3 and the slide gate valve in sequence before entering the granulator 2 for granulation. The submerged scraper conveyor 5 is located between the granulator 2 and the slide gate valve. The feed chute is located between the feed end of the granulator 2 and the discharge end of the submerged scraper conveyor 5. The dust output from the slide gate valve is conveyed by the submerged scraper conveyor 5 to the feed chute and then enters the granulator 2. The screw conveyor 6 is positioned between the slide gate valve and the submerged scraper conveyor 5. The dust output from the slide gate valve is conveyed to the submerged scraper conveyor 5 via the screw conveyor 6. The air hammer 7 is located at the bottom of the cyclone dust collector 1 and above the airlock star feeder 3. Preferably, the slide gate valve is a pneumatic double-layer slide gate valve 4.

[0024] During operation, dust is discharged from the cyclone dust collector 1, intermittently aided by air hammers 7 to knock it out. Then, it is conveyed by the airlock star feeder 3 to the pneumatic double-layer slide valve 4 (ash discharge valve), and subsequently enters the screw conveyor 6. From there, it is conveyed to the submerged scraper conveyor 5, and then to the feed chute of the granulator 2, finally entering the granulator 2 for granulation. It should be noted that the above conveying control process can be automatically controlled by a PLC or other controller, which is achievable with existing technology and will not be described further here.

[0025] Example 2 This embodiment is a further optimization of the dust collection system based on Embodiment 1. The dust collection system for the diammonium phosphate plant described in this embodiment consists of a cyclone dust collector 1, an air hammer 7, an airlock star feeder 3, a pneumatic double-layer slide valve 4, and a screw conveyor 6 forming a dust conveying line 8. Three dust conveying lines 8 are connected to the buried scraper conveyor 5, and the discharge ends of the three dust conveying lines 8 are respectively connected to (or connected to) the left, middle, and right ends of the buried scraper conveyor 5.

[0026] More specifically, each dust conveying line 8 includes two cyclone dust collectors 1 and one screw conveyor 6. The two cyclone dust collectors 1 are arranged side by side and share one screw conveyor 6. The bottom of each of the two cyclone dust collectors 1 in each dust conveying line 8 is respectively equipped with an air hammer 7, an airlock star feeder 3, and a pneumatic double-layer slide valve 4, and the output ends of the two pneumatic double-layer slide valves 4 are connected to the same screw conveyor 6.

[0027] More specifically, the dust conveying line 8 located at the left end of the buried scraper conveyor 5 has feed pipes 9 at the left end and middle section of its screw conveyor 6, and the output ends of the two gate valves of the dust conveying line 8 are respectively connected to the two feed pipes 9. The dust conveying lines 8 located at the middle and right ends of the buried scraper conveyor 5 have feed pipes 9 at the left end of their screw conveyors 6, and the output ends of the two pneumatic double-layer gate valves 4 of each dust conveying line 8 are all connected to the feed pipes 9.

[0028] Using the system of this utility model, dust leakage, secondary dust generation, and frequency of manual maintenance are effectively reduced, and the continuity and stability of system operation are significantly improved. It should be noted that the cyclone dust collector 1, granulator 2, airlock star feeder 3, pneumatic double-layer slide valve 4, submerged scraper conveyor 5, screw conveyor 6, air hammer 7, etc. in this application are all prior art. Existing technologies and corresponding installation methods or means can be directly adopted and set up according to the layout of the system of this application.

[0029] The specific embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A dust collection system for a diammonium phosphate plant, comprising a cyclone dust collector and a granulator, wherein the granulator is located at the ash discharge end of the cyclone dust collector to receive and granulate the dust separated by the cyclone dust collector, characterized in that: It also includes an airlock star feeder and a slide gate valve. The airlock star feeder and slide gate valve are installed at the ash discharge output end of the cyclone dust collector. The dust separated by the cyclone dust collector enters the granulator for granulation after passing through the airlock star feeder and slide gate valve in sequence.

2. The dust collection system for a diammonium phosphate plant according to claim 1, characterized in that: It also includes a submerged scraper conveyor and a feed chute. The submerged scraper conveyor is located between the granulator and the slide gate valve. The feed chute is located between the feed end of the granulator and the discharge end of the submerged scraper conveyor. The dust output by the slide gate valve is transported to the feed chute by the submerged scraper conveyor and then enters the granulator.

3. The dust collection system for a diammonium phosphate plant according to claim 2, characterized in that: It also includes a screw conveyor, which is located between the slide gate valve and the submerged scraper conveyor. The dust output from the slide gate valve is conveyed to the submerged scraper conveyor via the screw conveyor.

4. The dust collection system for a diammonium phosphate plant according to claim 3, characterized in that: It also includes an air hammer, which is located at the bottom of the cyclone dust collector and above the airlock star feeder.

5. The dust collection system for a diammonium phosphate plant according to claim 4, characterized in that: The slide gate valve is a pneumatic double-layer slide gate valve.

6. The dust collection system for a diammonium phosphate plant according to claim 5, characterized in that: The cyclone dust collector, air hammer, airlock star feeder, pneumatic double-layer slide valve and screw conveyor mechanism form a dust conveying line, and at least three of the dust conveying lines are connected to the buried scraper conveyor.

7. The dust collection system for a diammonium phosphate plant according to claim 6, characterized in that: The buried scraper conveyor is connected to three dust conveying lines, and the discharge ends of the three dust conveying lines are respectively connected to the left, middle and right ends of the buried scraper conveyor.

8. The dust collection system for a diammonium phosphate plant according to claim 7, characterized in that: Each dust conveying line includes two cyclone dust collectors and one screw conveyor. The two cyclone dust collectors are arranged side by side and share one screw conveyor.

9. The dust collection system for a diammonium phosphate plant according to claim 8, characterized in that: Each of the two cyclone dust collectors on each dust conveying line is equipped with an air hammer, an airlock star feeder, and a pneumatic double-layer slide valve at the bottom, and the output ends of the two pneumatic double-layer slide valves are connected to the same screw conveyor.

10. The dust collection system for a diammonium phosphate plant according to claim 9, characterized in that: The screw conveyor is provided with a feed pipe at its left end, and the output ends of the two pneumatic double-layer gate valves of each dust conveying line are connected to the feed pipe; or, the screw conveyor is provided with feed pipes at its left end and middle part, and the output ends of the two gate valves of each dust conveying line are connected to the two feed pipes respectively.

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