Recovery device for nitrogen conveying

Abstract

The utility model belongs to the technical field of nitrogen recovery, and particularly relates to a recovery device for nitrogen conveying. The cyclone separator is used for primary separation of large-particle impurities; the bag-type dust collector is used for secondary separation of small-particle impurities; the compressor is used for compressing nitrogen; the cyclone separator, the bag-type dust collector and the compressor are connected in sequence; the dust collection box is matched with the bag-type dust remover; the dust discharging plate is rotationally connected with the dust collecting box; the air bag is fixedly connected with the dust discharging plate, and the air bag is matched with the dust collecting box. According to the scheme, the problem that dust leaks due to the fact that a dust discharging valve switch is easily blocked by impurities is solved.

Description

Technical Field

[0001] This utility model belongs to the field of nitrogen recovery technology, specifically relating to a recovery device for nitrogen transportation. Background Technology

[0002] The closed-loop pneumatic conveying system for calcium carbide purification ash consumes a large amount of nitrogen, resulting in high gas supply costs and seriously affecting the normal operation of the system. Therefore, it is of great importance to study key technologies for nitrogen recovery and design a closed-loop nitrogen circulation system to automatically recover the nitrogen used in the conveying process and recycle it after pressurization by a nitrogen compressor. This method enables the automatic operation of the nitrogen recovery system.

[0003] Currently, the existing calcium carbide furnace purified ash return combustion system (publication number CN103759546A) includes a sealed purified ash collection bin, a pneumatic conveyor, a sealed feeding bin, a conveying gas source, and a mixing chamber. Nitrogen gas is introduced into both the sealed purified ash collection bin and the pneumatic conveyor, connecting them. A pneumatic conveying pipe connects the sealed feeding bin and the pneumatic conveyor, and nitrogen gas is also introduced into the pneumatic conveying pipe. The conveying gas source is the pressure source for terminal delivery. This system can directly transport and recycle purified ash from calcium carbide production equipment on-site, overcoming the difficulties in recycling and transporting purified ash due to its high temperature, flammability, explosiveness, and adhesion properties, achieving smooth and unblocked on-site transportation. The sealed feeding bin ensures a stable supply of purified ash into the combustion furnace. It eliminates transportation costs associated with purified ash recycling, increases output value and profits, achieves energy savings, and reduces pollutant emissions.

[0004] Another baghouse dust collector, disclosed in CN116585821A, includes a dust collection tank body, a main support frame installed below the dust collection tank body, a hopper fixed below the dust collection tank body, a silo fixed below the hopper, and a discharge pipe fixed below the silo. The discharge pipe and the silo are interconnected, and a discharge auger is installed inside the discharge pipe. This invention uses an electric valve body to open a nitrogen input structure, allowing nitrogen to be discharged from the nitrogen nozzle through the cooperation of the nitrogen input pipe and the nitrogen nozzle. Furthermore, the first motor, the rotary level sensor body, and the electric valve body open and close synchronously, ensuring that nitrogen is only introduced into the silo during discharge to increase the stability of dust particle discharge. Compared to periodic discharge methods, this avoids empty discharge and reduces the waste of nitrogen.

[0005] However, there is also a problem: the dust discharge valve switch of the bag filter in this solution is easily blocked by impurities, which can cause gaps in the switch and lead to dust leakage. Utility Model Content

[0006] This solution provides a recovery device for nitrogen transportation to solve the problem of dust leakage caused by impurities clogging the dust discharge valve switch.

[0007] This solution provides a recovery device for nitrogen transportation, including a cyclone separator for primary separation of large particulate impurities;

[0008] Baghouse dust collector: used for secondary separation of small particulate impurities;

[0009] Compressor: Used to compress nitrogen gas;

[0010] The cyclone separator, bag filter, and compressor are connected in sequence.

[0011] Also includes:

[0012] Dust collection box: The dust collection box is used in conjunction with the bag filter dust collector;

[0013] Dust removal plate: The dust removal plate is rotatably connected to the dust collection box;

[0014] Airbag: The airbag is fixedly connected to the dust removal plate and cooperates with the dust collection box.

[0015] The principle of this solution is as follows: Dust-laden gas enters the cyclone separator at high speed. Under centrifugal force, large particles are thrown against the wall and fall downwards into the bottom collection area. The purified gas is discharged from the top. The gas after being processed by the cyclone separator enters the baghouse dust collector, where fine dust particles are captured on the surface of the filter bags. Clean gas passes through the filter bags and is discharged. The dust accumulated on the filter bags is periodically removed by a cleaning system. When the baghouse dust collector performs a cleaning operation, the dislodged dust falls into the dust collection box below for centralized storage.

[0016] The air bladder can be inflated or deflated to adjust the position of the dust removal plate, ensuring it can properly abut against the dust collection box. When the dust collection box needs to be closed, the dust removal plate is rotated to the connection point between the dust collection box and the bag filter, and then the air bladder is inflated, causing it to expand and lock the dust removal plate in place, forming a seal. When the dust removal plate needs to be opened, the air is extracted from the air bladder, and the dust removal plate opens due to gravity. This achieves automated dust emission control, reduces manual intervention, and improves efficiency and safety.

[0017] The compressor draws in clean gas from the bag filter and increases its pressure through mechanical compression, ultimately outputting high-pressure nitrogen.

[0018] The beneficial effects of this solution are as follows: 1. This solution uses airbags to open and close the dust collection plate. The airbags are extensible, so even if impurities adhere to the dust collection box, they can still be sealed shut to prevent internal gas from escaping. 2. Through two-stage purification using a cyclone separator and a bag filter, large and small particulate impurities in the nitrogen can be effectively removed, ensuring the purity of the output nitrogen.

[0019] Furthermore, the bag filter includes a housing, an air inlet pump, and dust bags. The housing is provided with an air inlet pipe and an air outlet pipe. Multiple dust bags are provided and are arranged at equal intervals inside the housing. The openings of the dust bags are connected to the air outlet pipes. The air inlet pump is connected to the air inlet pipes.

[0020] The intake pump delivers gas into the housing. Once inside, the gas, laden with dust, is slowed down by the reduced airflow and the filter bags' surface acts as a barrier, causing larger particles to settle directly into the dust hopper, while smaller particles are captured by the dust bags. The gas then exits through the dust bag openings and the outlet pipe. The equidistant arrangement of the dust bags helps ensure uniform gas distribution throughout the housing, preventing premature damage or clogging of the filter bags due to excessively concentrated airflow in localized areas.

[0021] Furthermore, it also includes a fixing frame, which is fixedly connected to the housing and cooperates with the dust bag. The fixing frame can fix the dust bag and prevent the dust bag from shaking due to airflow, causing the dust bags to become knotted together.

[0022] Furthermore, it also includes an adjustment mechanism, which includes a cylinder, a piston, and a connecting rod. The cylinder is fixedly connected to the housing, the piston is slidably and sealed to the cylinder, one end of the connecting rod is hinged to the piston, and the other end is hinged to the dust discharge plate. The cylinder is provided with a connecting pipe, which is connected to the airbag.

[0023] The cylinder is located above the dust removal plate. When the operator closes the dust removal plate, the connecting rod moves upward, causing the piston to move upward. The upward movement of the piston allows air to flow through the cylinder to the connecting pipe, causing the airbag to inflate. The airbag assists in sealing and locking the dust removal plate.

[0024] When the operator needs to open the dust removal plate, the operator pulls the dust removal plate forcefully to open it. The connecting rod will move downward, driving the piston downward, causing the cylinder to draw in air and the air bladder to contract, allowing the dust on the dust removal plate to slide off smoothly due to gravity.

[0025] This device achieves automatic inflation and deflation of the airbag through an adjustment mechanism, saving steps and improving efficiency.

[0026] Furthermore, it also includes an automatic dust removal mechanism, which includes a spring and a magnetic ring. One end of the spring is fixedly connected to the piston, and the other end is fixedly connected to the cylinder. The magnetic ring is fixedly connected to the cylinder and cooperates with the piston, which is made of ferromagnetic material.

[0027] Since gas dust removal is a continuous operation, it's not feasible to manually open the dust discharge plate every time. Excessive dust accumulation, on the other hand, can negatively impact the performance of the baghouse dust collector.

[0028] In this design, when dust accumulates to a set weight on the dust removal plate, the weight of the dust overcomes the magnetic ring's attraction and the airbag's friction, causing the dust removal plate to open. The airbag then contracts, allowing the dust to slide into the dust collection box. Once the dust has fallen in, the spring, without its weight, causes the piston to return to its original position, while the connecting rod pulls the dust removal plate closed.

[0029] When the piston returns to its original position, it fills the air bladder with gas, which seals the gap between the dust discharge plate and the dust collection box, preventing dust from flowing out. This mechanism enables automatic dust discharge at regular intervals, achieving automation and improving efficiency.

[0030] Furthermore, it also includes a backflushing mechanism, which comprises a backflushing pump and a backflushing pipe. One end of the backflushing pipe is connected to the opening of the dust bag, and the other end is connected to the backflushing pump. Long-term use of the dust bag can cause excessive dust to adhere to the bag surface, leading to filter clogging. In this solution, the operator activates the backflushing pump at set intervals, allowing pulsed airflow to enter the housing from the backflushing pipe and then enter through the opening of the dust bag for pulsed backflushing.

[0031] Furthermore, it also includes a cooling device used in the cold zone compressor, which works in conjunction with the compressor. When the compressor compresses, it generates a large amount of heat. At this time, the cooling device activates to cool the compressor, which could cause the compressor to overheat and damage the device. Attached Figure Description

[0032] Figure 1 This is a structural diagram of a bag filter dust collector used for nitrogen transport and recovery.

[0033] Figure 2 This is a cross-sectional view of a bag filter dust collector used for nitrogen transport and recovery.

[0034] Figure 3 This is an enlarged view of the dust discharge plate of the regulating mechanism of a nitrogen transport recovery device when it is closed.

[0035] Figure 4 This is an enlarged view of the dust discharge plate of the regulating mechanism of a nitrogen transport recovery device when it is open.

[0036] The reference numerals in the accompanying drawings include: 1. Housing; 2. Backflush pump; 3. Ash hopper; 4. Fixing foot; 5. Ladder; 6. Backflush pipe; 7. Fixing frame; 8. Dust bag; 9. Dust discharge plate; 10. Dust collection box; 11. Airbag; 12. Connecting rod; 13. Piston; 14. Cylinder; 15. Connecting pipe; 16. Spring; 17. Magnetic ring; 18. Inlet pipe. Detailed Implementation

[0037] This project addresses the problem of high nitrogen consumption and high gas supply costs in closed-loop pneumatic conveying systems for calcium carbide purification ash, which seriously affect the normal operation of the pneumatic conveying system. By studying key technologies for nitrogen recovery, a closed-loop nitrogen circulation system is designed to automatically recover the nitrogen used in the conveying process. The nitrogen is then pressurized by a nitrogen compressor and reused, thus realizing the automatic operation of the nitrogen recovery system.

[0038] Working principle of pneumatic conveying system: Currently, dense-phase fluidized bed pneumatic conveying technology is used. The principle is to first fluidize the calcium carbide furnace purification ash powder using compressed gas, and then use compressed gas to convey the fluidized material at high concentration and high pressure. This conveying method features low speed, high concentration, low wear, and low vibration, making it particularly suitable for long-distance, high-flow-rate powder conveying. Its characteristics include: low speed, dense phase, low gas consumption, and simple separation of conveying tail gas, etc. The gas (nitrogen)-material (purified ash) mixture sent from the calcium carbide furnace to the purification ash silo near the fluidized bed furnace falls into the purification ash silo after being filtered by a primary dust collector at the top of the silo. Positive and negative pressure Roots blower conveying mainly utilizes the principle of large-volume dilute-phase conveying.

[0039] This embodiment provides a nitrogen recovery device for nitrogen transport, comprising a cyclone separator, a bag filter, a gas storage device, a nitrogen compressor, and a cooling device connected in sequence.

[0040] Design principle of nitrogen closed-loop circulation system

[0041] Circulation Process Design: A complete nitrogen circulation path is constructed, starting from the end of the pneumatic conveying pipeline, introducing dust-laden nitrogen into the recovery unit. In the recovery unit, dust is removed through devices such as cyclone separators and filters, achieving initial purification of the nitrogen. The purified nitrogen then enters the nitrogen compressor, is pressurized, and is returned to the front end of the pneumatic conveying system, realizing recycling.

[0042] Key equipment selection

[0043] Nitrogen compressor: Select a suitable nitrogen compressor model based on the system's required nitrogen flow rate and pressure boost. Consider factors such as compressor compression ratio, discharge capacity, power consumption, reliability, and ease of maintenance.

[0044] Dust separation equipment: A combination of high-efficiency cyclone separators and bag filters is used to ensure that the dust removal rate meets the circulation requirements. Based on the nitrogen flow rate and dust concentration, a reasonable separator size and filtration accuracy are designed to ensure separation efficiency while minimizing resistance to nitrogen flow.

[0045] Gas storage device: A gas storage tank of a certain volume is installed to balance the fluctuations in nitrogen pressure within the system and ensure a stable gas supply. The volume of the gas storage tank needs to be calculated and determined based on the maximum flow rate and pressure variation range of the system.

[0046] Pressure control: Pressure sensors are installed at key points in the circulation system to monitor nitrogen pressure in real time. The nitrogen compressor speed or inlet valve opening is adjusted by a pressure controller to maintain the nitrogen pressure within the set range, ensuring the stability and safety of pneumatic delivery.

[0047] Flow control: A flow meter is used to measure the nitrogen circulation flow rate, and the nitrogen flow rate is dynamically adjusted based on factors such as the amount of material being conveyed and the conveying distance. Variable frequency technology or flow regulating valves are employed to achieve precise control of the nitrogen flow rate, avoiding energy waste due to excessive flow or affecting conveying efficiency due to insufficient flow.

[0048] Safety protection measures: An overpressure protection device is installed, which automatically opens the safety valve to release pressure when the system pressure exceeds the safety threshold. Temperature monitoring devices are also provided to prevent safety accidents caused by excessive temperature rise due to nitrogen compression. Dust concentration monitors are installed in the recovery unit and conveying pipelines; if the dust concentration exceeds the standard, the purification equipment will be activated immediately or appropriate measures will be taken.

[0049] System performance testing and optimization

[0050] Simulation Testing: A laboratory-scale model of a closed-loop nitrogen circulation system was built to simulate actual operating conditions. By changing parameters such as nitrogen flow rate, pressure, and dust concentration, the system's operating performance was monitored, including indicators such as nitrogen recovery rate, dust removal rate, and compressor energy consumption.

[0051] Actual operation testing: Pilot installation and operation testing were conducted on the calcium carbide furnace gas purification ash collection device to collect actual production data. Nitrogen consumption, gas supply costs, and unit start-up rate were compared before and after the modification to evaluate the system's actual application effect.

[0052] Optimization plan development: Based on the test results, analyze the problems and shortcomings of the system, and propose targeted optimization plans. Adjust and improve equipment selection, operating parameters, control strategies, etc., to further improve the system's performance and economy.

[0053] As attached Figure 1 , Figure 2 As shown:

[0054] The baghouse dust collector includes a housing 1, an inlet pipe 18, an outlet pipe, a dust bag 8, and a dust discharge hopper 3. The bottom of the housing 1 is supported by fixed feet 4, and a ladder 5 is provided on the side for maintenance.

[0055] The opening of the dust bag 8 is connected to the air outlet pipe. A backwash pump 2 is provided on the top of the housing 1. The backwash pump 2 is connected to the opening of the dust bag 8 through the backwash pipe 6 for pulse backwashing.

[0056] Multiple dust bags 8 are arranged equidistantly inside the housing 1. The dust bags 8 are divided into two groups, with the openings of the two groups located at the first connecting port and the second connecting port, respectively. Both the first connecting port and the second connecting port are connected to the backwash pipe 6, and both the first connecting port and the second connecting port are connected to the air outlet pipe. The backwash pipe 6 is equipped with a three-way valve, and the air outlet pipe and the air inlet pipe 18 are equipped with one-way valves. When the backwash pump 2 performs backwashing, it only needs to backwash one group of dust bags 8, thus allowing for rinsing without stopping the machine.

[0057] The fixed frame 7 is fixedly connected to the inner wall of the housing 1, and the dust bag 8 is positioned by the fixed frame 7 to prevent entanglement due to airflow. The dust discharge hopper 3 is located at the bottom of the housing 1, and the dust collection box 10 is connected below it. The dust collection box 10 is opened and closed by the dust discharge plate 9.

[0058] As attached Figure 2 , Figure 4 As shown:

[0059] The dust discharge plate 9 is rotatably connected to the dust collection box 10 via a hinge shaft. The airbag 11 is fixed to the sealing surface of the dust discharge plate 9 and mates with the interface of the dust collection box 10.

[0060] The adjusting mechanism includes a cylinder 14, a piston 13 and a connecting rod 12. The cylinder 14 is fixedly connected to the ash discharge hopper 3, the piston 13 is slidably and sealed to the cylinder 14, one end of the connecting rod 12 is hinged to the piston 13 and the other end is hinged to the dust discharge plate 9, and the cylinder 14 is provided with a connecting pipe 15, which is connected to the air bag 11.

[0061] It also includes an automatic dust removal mechanism, which includes a spring 16 and a magnetic ring 17. One end of the spring 16 is fixedly connected to the piston 13 and the other end is fixedly connected to the cylinder 14. The magnetic ring 17 is fixedly connected to the cylinder 14 and cooperates with the piston 13, which is made of ferromagnetic material.

[0062] As attached Figure 1-4 As shown:

[0063] The principle of this scheme is as follows: dust-laden gas enters the cyclone separator at high speed. Under the action of centrifugal force, large particles are thrown against the wall and fall downwards into the bottom collection area. The purified gas is discharged from the top. The gas processed by the cyclone separator then enters the bag filter.

[0064] The intake pump delivers gas into the housing 1. Upon entering the housing 1, the airflow speed slows down and the filter bag surface acts as a barrier, causing larger particles to settle directly into the dust hopper, while smaller particles are captured by the dust bags 8. The gas then exits through the openings of the dust bags 8 and the outlet pipe. The equidistant arrangement of the dust bags 8 helps ensure uniform distribution of the dust-laden gas throughout the housing 1, preventing premature damage or clogging of the filter bags due to excessively concentrated airflow in localized areas. The detached dust falls into the dust collection box 10 below for centralized storage.

[0065] When dust accumulates on the dust removal plate 9 to a set weight, the weight of the dust overcomes the attraction of the magnetic ring 17 and the friction of the air bag 11, causing the dust removal plate 9 to open. The connecting rod 12 moves downward, driving the piston 13 downward, causing the cylinder 14 to draw in air, and the air bag 11 to contract. At this time, the dust will slide into the dust collection box 10. After the dust falls in, since there is no weight from the dust, the spring 16 will return the piston 13 to its original position, and at the same time, the connecting rod 12 will pull the dust removal plate 9 to close.

[0066] When piston 13 returns to its original position, it fills the airbag 11 with gas, which seals the gap between the dust discharge plate 9 and the dust collection box 10, preventing dust from flowing out. This mechanism enables automatic dust discharge at regular intervals, achieving automation and improving efficiency.

[0067] The compressor draws in clean gas from the bag filter and increases its pressure through mechanical compression, ultimately outputting high-pressure nitrogen. The compressor generates a large amount of heat during compression, at which point the cooling system activates to cool the compressor. However, overheating of the compressor can lead to damage.

[0068] The beneficial effects of this solution are as follows: 1. This solution uses an airbag 11 to open and close the dust removal plate 9. The airbag 11 is extensible, so even if impurities adhere to the dust collection box 10, it can still be sealed shut to prevent internal gas from escaping. 2. Through two-stage purification using a cyclone separator and a bag filter, large and small particulate impurities in the nitrogen can be effectively removed, ensuring the purity of the output nitrogen. 3. This mechanism achieves automatic dust removal at regular intervals, realizing automation and improving efficiency.

[0069] The above descriptions are merely embodiments of this utility model, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of this utility model, and these should also be considered within the scope of protection of this utility model. These modifications will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application shall be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A recycling device for nitrogen delivery, comprising: a cyclone separator for primary separation of large-particle impurities; a bag filter for secondary separation of small-particle impurities; a compressor for compressing nitrogen; the cyclone separator, bag filter and compressor are connected in sequence; characterized in that it further comprises: a dust collection box (10) cooperating with the bag filter; a dust unloading plate (9) rotatably connected with the dust collection box (10); an air bag (11) fixedly connected with the dust unloading plate (9) and cooperating with the dust collection box (10).

2. A recovery device for nitrogen delivery according to claim 1, wherein, The bag filter comprises a housing (1), an air inlet pump and dust bags (8), the housing (1) is provided with an air inlet pipe (18) and an air outlet pipe; the dust bags (8) are arranged equidistantly in the housing (1), and the openings of the dust bags (8) are communicated with the air outlet pipe; the air inlet pump is communicated with the air inlet pipe (18).

3. A recovery device for nitrogen delivery according to claim 2, wherein, It further comprises a fixed frame (7) fixedly connected with the housing (1) and cooperating with the dust bags (8).

4. A recovery device for nitrogen delivery according to claim 2, wherein, It further comprises an adjusting mechanism comprising a cylinder (14), a piston (13) and a connecting rod (12), the cylinder (14) is fixedly connected with the housing (1), the piston (13) is slidingly and sealingly connected with the cylinder (14), one end of the connecting rod (12) is hingedly connected with the piston (13), and the other end is hingedly connected with the dust unloading plate (9); the cylinder (14) is provided with a communication pipe (15) communicated with the air bag (11).

5. A recovery device for nitrogen delivery according to claim 4, wherein, It further comprises an automatic dust unloading mechanism comprising a spring (16) and a magnetic ring (17), one end of the spring (16) is fixedly connected with the piston (13), and the other end is fixedly connected with the cylinder (14); the magnetic ring (17) is fixedly connected with the cylinder (14) and cooperates with the piston (13), and the piston (13) is a ferromagnetic material.

6. A recovery device for nitrogen delivery according to claim 2, wherein, It further comprises a backflushing mechanism comprising a backflushing pump (2) and a backflushing pipe (6), one end of the backflushing pipe (6) is communicated with the opening of the dust bag (8), and the other end is communicated with the backflushing pump (2).

7. A recovery device for nitrogen delivery according to claim 1, wherein, It further comprises a cooling device for cooling the compressor, and the cooling device cooperates with the compressor.

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