Energy-saving circulation conveying system and method

Abstract

The invention relates to the technical field of metal powder conveying, and discloses an energy-saving circulating conveying system and method, wherein a primary fan unit, a conveying unit, a primary filter tank, a primary variable frequency dust collector, a secondary filter tank, and a secondary variable frequency dust collector are connected in sequence to form a nitrogen circulation loop; a pressure value P1 is monitored at the air outlet side of the primary fan unit, a pressure value P2 is monitored at the air inlet side of the primary filter tank, a pressure value P3 is monitored at the air outlet side of the primary variable frequency dust collector, a pressure value P4 is monitored at the air outlet side of the secondary variable frequency dust collector, and a pressure value P5 is monitored at the air inlet side of the primary fan unit; a controller controls the operation of the primary fan unit to maintain P1>P2>P3>P4>P5; when the pressure difference between P2 and P3 is greater than the first difference, the operating frequency of the primary variable frequency dust collector is increased; when the pressure difference between P3 and P4 is greater than the second difference, the operating frequency of the secondary variable frequency dust collector is increased to stabilize the conveying pressure.

Description

Technical Field

[0001] The invention relates to the technical field of metal powder material conveying, and in particular to an energy-saving circulating conveying system and method. Background Art

[0002] Some powder materials in the chemical industry are not allowed to be transported by compressed air, especially some active metal powders. Compressed air contains moisture and oxygen, which is not suitable for the transportation of such materials, such as fine aluminum powder. Nitrogen is a good power for transporting such materials. The gas source of the traditional nitrogen transportation system is a one-time transportation loss and will not be recycled. Therefore, the operating cost of nitrogen is very high, and the cost is very high when transporting large quantities of gas.

[0003] Therefore, to ensure reliable safety and economic efficiency, the recycling of nitrogen is an effective way to solve this problem. At the same time, in the traditional nitrogen delivery system, there is an unstable system pressure, which causes unstable powder delivery and waste of nitrogen. Summary of the invention

[0004] One of the purposes of the present invention is to provide an energy-saving circulating transportation method which saves nitrogen and improves transportation stability.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] An energy-saving circulation conveying method, comprising:

[0007] System configuration: The primary fan unit, the conveying unit, the primary filter tank, the primary variable frequency dust collector, the secondary filter tank, and the secondary variable frequency dust collector are connected in sequence by pipelines to form a nitrogen circulation loop, and the terminal bin is connected to the discharge ends of the primary filter tank and the secondary filter tank; a first pressure gauge is configured on the air outlet side of the primary fan unit to monitor the pressure value P1, a second pressure gauge is configured on the air inlet side of the primary filter tank to monitor the pressure value P2, a third pressure gauge is configured on the air outlet side of the primary variable frequency dust collector to monitor the pressure value P3, a fourth pressure gauge is configured on the air outlet side of the secondary variable frequency dust collector to monitor the pressure value P4, and a fifth pressure gauge is configured on the air inlet side of the primary fan unit to monitor the pressure value P5;

[0008] Feeding control: The controller obtains the pressure values ​​obtained by each pressure gauge, controls the operation of the first-level fan unit, and maintains P1>P2>P3>P4>P5; determines whether the pressure difference △P23 between P2 and P3 is greater than the first difference, if so, increases the operating frequency of the first-level variable frequency dust collector until △P23 is less than the first difference, if not, maintains the current operating frequency of the first-level variable frequency dust collector; determines whether the pressure difference △P34 between P3 and P4 is greater than the second difference, if so, increases the operating frequency of the second-level variable frequency dust collector until △P34 is less than the second difference, if not, maintains the current operating frequency of the second-level variable frequency dust collector.

[0009] Furthermore, the system configuration also includes configuring a nitrogen supply unit, connecting the nitrogen supply unit pipeline to the air inlet side of the primary fan unit to supply and replenish nitrogen for the nitrogen circulation loop; also includes configuring a ventilation unit on the air outlet side of the secondary variable frequency dust collector, and setting a nitrogen concentration detection sensor on the air outlet side of the secondary variable frequency dust collector to monitor the reflux nitrogen concentration K of the nitrogen circulation loop; also includes an air pressure field establishment step and a nitrogen replacement step; the air pressure field establishment step is: closing the nitrogen supply unit, opening the ventilation unit and the primary fan unit to blow in air, when P1>P2>P3>P4>P5, completing the air pressure field establishment, and entering the nitrogen replacement step;

[0010] The nitrogen replacement step is: turn on the ventilation unit, turn on the nitrogen supply unit, maintain P1>P2>P3>P4, and replace the air; when the nitrogen concentration detection sensor detects that the nitrogen concentration K reaches the replacement concentration threshold KH, turn off the ventilation unit, end the nitrogen replacement, and enter the feeding control step.

[0011] Furthermore, it also includes an operation monitoring step: the controller is also configured to open the nitrogen supply unit to replenish nitrogen when the nitrogen concentration K is less than the replenishment concentration threshold K1, and close the nitrogen supply unit when K=KH; when the nitrogen concentration K is less than the replacement concentration threshold K2, start the nitrogen replacement step; wherein K1>K2.

[0012] Furthermore, the system configuration also includes configuring a first flow meter and an adjustable air replenishment valve on the air outlet side of the nitrogen supply unit, the first flow meter monitors the output flow Q1 of the nitrogen supply unit, and the adjustable air replenishment valve controls the output flow of the nitrogen supply unit; configuring a second adjustable ventilation valve and a third check valve at the atmospheric end of the ventilation unit; when the nitrogen supply unit is opened to replenish nitrogen when the nitrogen concentration K is less than the air replenishment concentration threshold K1, the amount of nitrogen to be injected Qb is calculated according to the nitrogen concentration K, the adjustable air replenishment valve is opened to replenish air, and the injected nitrogen is measured by the first flow meter; the second adjustable ventilation valve is opened at a certain opening until K=KH, and the adjustable air replenishment valve and the second adjustable ventilation valve are closed.

[0013] Furthermore, the system configuration also includes configuring a first flow meter and an adjustable air supply valve on the air outlet side of the nitrogen supply unit, the first flow meter monitors the output flow Q1 of the nitrogen supply unit, and the adjustable air supply valve controls the output flow of the nitrogen supply unit; configuring a second flow meter on the air outlet side of the secondary variable frequency dust collector to monitor the reflux nitrogen flow Q2 of the nitrogen circulation loop; and also includes an operation monitoring step, the controller is further configured to obtain the reflux nitrogen flow Q2, and when the nitrogen flow Q2 is less than the set value Q, open the adjustable air supply valve to supply air, and the air supply amount is k (Q-Q2), and k is a safety factor greater than 1.

[0014] Furthermore, it also includes a filter tank unloading step: configuring the capacity of the first-level filter tank to be larger than the capacity of the second-level filter tank, when the ash amount in the first-level filter tank / second-level filter tank reaches the level meter alarm, the controller controls the first-level filter tank / second-level filter tank to start unloading to the terminal warehouse; the controller controls the first-level filter tank and the second-level filter tank to unload in time.

[0015] Furthermore, in the system configuration, a gas refrigeration dryer is configured at the front end of the primary fan unit, and a thermometer is configured at the front end of the gas refrigeration dryer to monitor the reflux gas temperature TX of the nitrogen circulation loop; the controller is configured with a temperature lower limit value T1 and a temperature upper limit value T2, when T1<TX<T2, the controller controls the gas refrigeration dryer to stop; when TX>T2, the controller controls the gas refrigeration dryer to start, and shuts down the gas refrigeration dryer until TX<T1.

[0016] A second object of the present invention is to provide an energy-saving circulating conveying system that saves nitrogen and improves conveying stability.

[0017] To achieve the above object, the present invention adopts the following technical solutions:

[0018] An energy-saving circulation conveying system, comprising:

[0019] Primary fan unit, conveying unit, primary filter tank, primary variable frequency dust collector, secondary filter tank, secondary variable frequency dust collector, terminal bin, sensor group and controller;

[0020] The primary fan unit, the conveying unit, the primary filter tank, the primary variable frequency dust collector, the secondary filter tank, and the secondary variable frequency dust collector are connected in sequence to form a nitrogen circulation loop, and the terminal bin is connected to the discharge ends of the primary filter tank and the secondary filter tank;

[0021] The sensor group includes a first pressure gauge, a second pressure gauge, a third pressure gauge, a fourth pressure gauge and a fifth pressure gauge, the first pressure gauge is connected in series to the air outlet side of the first-level fan unit, the second pressure gauge is connected in series to the air inlet side of the first-level filter tank, the third pressure gauge is connected in series to the air outlet side of the first-level variable frequency dust collector, the fourth pressure gauge is connected in series to the air outlet side of the second-level variable frequency dust collector, and the fifth pressure gauge is connected in series to the air inlet side of the first-level fan unit;

[0022] The controller executes the aforementioned method.

[0023] Preferably, it also includes a nitrogen supply unit, which is connected to the air inlet side of the first-level fan unit. When the pressure value of P5 is less than the third difference, the controller turns on the nitrogen supply unit to supply and replenish nitrogen for the nitrogen circulation loop.

[0024] Preferably, it also includes a ventilation unit, which is connected to the air inlet side of the first-level fan unit and is used to discharge part of the gas in the pipeline when replacing nitrogen.

[0025] After adopting the above technical solution, the present invention has the following advantages compared with the background technology:

[0026] 1. The present invention realizes the recycling of nitrogen by configuring a nitrogen circulation loop, thereby saving energy and reducing emissions, and reducing the cost of material distribution and transportation;

[0027] 2. During operation, the present invention monitors the pressure difference between the air inlet side and the air outlet side of the first-stage variable frequency dust collector, and monitors the pressure difference between the air inlet side and the air outlet side of the second-stage variable frequency dust collector, and then automatically adjusts the operating frequency of the first-stage variable frequency dust collector and the second-stage variable frequency dust collector to stabilize the conveying pressure; at the same time, the pressure requirement of the system is reduced, and ordinary low-pressure fans can be used for direct conveying, thereby achieving energy saving;

[0028] 3. The present invention first establishes an air pressure field in the ventilation unit before nitrogen delivery to detect the pipeline status, and then performs nitrogen replacement to avoid nitrogen loss caused by pipeline abnormalities, thereby further saving energy and reducing emissions;

[0029] 4. During operation, the present invention further ensures the reliability of material transportation by monitoring the nitrogen concentration and adopting corresponding gas replenishment strategies;

[0030] 5. During operation, the present invention further ensures the reliability of material transportation by monitoring the nitrogen reflux flow and adopting corresponding gas replenishment strategies. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the energy-saving circulation conveying system of the present invention;

[0032] Figure 2 This is a schematic diagram of the process of controlling a primary variable frequency dust collector according to the present invention;

[0033] Figure 3 It is a schematic diagram of the process of controlling the two-stage variable frequency dust collector of the present invention;

[0034] Figure 4 This is the preparation process before feeding of the present invention;

[0035] Figure 5 This is a schematic diagram of the nitrogen concentration detection replacement process;

[0036] Figure 6 This is a schematic diagram of the nitrogen flow detection replacement process;

[0037] Figure 7 is a schematic diagram of a nitrogen supply unit;

[0038] Figure 8 is a schematic diagram of a conveying unit;

[0039] Fig. 9 This is a schematic diagram of the unloading part.

[0040] Description of reference numerals:

[0041] 100, nitrogen supply unit; 110, high-pressure gas storage tank; 111, first check valve; 112, first pressure regulating valve; 120, low-pressure gas storage tank; 121, second pressure regulating valve; 122, adjustable air supply valve;

[0042] 200, primary fan unit; 210, second check valve;

[0043] 300, conveying unit; 310, ash hopper; 320, ash hopper discharge valve; 330, collecting tank; 340, discharge valve; 350, electric discharger; 360, ash-gas combiner; 370, ash hopper balance valve;

[0044] 410, primary filter tank; 411, first discharge valve; 412, first balance valve; 420, primary variable frequency dust collector; 430, secondary filter tank; 431, second discharge valve; 432, second balance valve; 440, secondary variable frequency dust collector;

[0045] 500, terminal warehouse;

[0046] 600, ventilation unit; 610, third check valve; 620, second adjustable ventilation valve; 630, first adjustable ventilation valve;

[0047] 700. Gas refrigeration dryer;

[0048] 800, two-stage fan unit;

[0049] 910, a first pressure gauge; 920, a second pressure gauge; 930, a third pressure gauge; 940, a fourth pressure gauge; 950, a fifth pressure gauge; 960, a nitrogen concentration detection sensor; 970, a thermometer; 980, a first flow meter; 990, a second flow meter. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, it should be noted that:

[0051] The terms "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element of the present invention must have a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0052] When an element is referred to as being “fixed to” or “disposed on” or “provided on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0053] Unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0054] Example 1

[0055] The invention discloses an energy-saving circulation conveying method, which comprises system configuration and feeding control steps.

[0056] Among them, please refer to Figure 1 As shown, in the system configuration step, the nitrogen supply unit 100, the primary fan unit 200, the conveying unit 300, the primary filter tank 410, the primary variable frequency dust collector 420, the secondary filter tank 430, and the secondary variable frequency dust collector 440 are connected in sequence by pipelines to form a nitrogen circulation loop.

[0057] That is, the nitrogen supply unit 100 provides the required nitrogen, and then the primary fan unit 200 provides the airflow power for nitrogen circulation. After the nitrogen airflow passes through the conveying unit 300, it conveys the powder material released by the conveying unit 300 to the primary filter tank 410, the primary variable frequency dust collector 420, the secondary filter tank 430, and the secondary variable frequency dust collector 440 in sequence for filtration, and then returns to the primary fan unit 200 to recycle the nitrogen. The powder material filtered by the primary filter tank 410, the primary variable frequency dust collector 420, the secondary filter tank 430, and the secondary variable frequency dust collector 440 falls into the terminal bin 500, completing the material transportation.

[0058] At the same time, in order to stabilize the system delivery pressure, in the system configuration step, a first pressure gauge 910 is configured on the air outlet side of the first-level fan unit 200 to monitor the pressure value P1, a second pressure gauge 920 is configured on the air inlet side of the first-level filter tank 410 to monitor the pressure value P2, a third pressure gauge 930 is configured on the air outlet side of the first-level variable frequency dust collector 420 to monitor the pressure value P3, a fourth pressure gauge 940 is configured on the air outlet side of the second-level variable frequency dust collector 440 to monitor the pressure value P4, and a fifth pressure gauge 950 is configured on the air inlet side of the first-level fan unit 200 to monitor the pressure value P5.

[0059] Thus, in the feeding control step, the controller obtains the pressure values ​​obtained by each pressure gauge, and controls the operation of the primary blower unit 200 to maintain P1>P2>P3>P4>P5, so that the nitrogen can circulate.

[0060] Also, please refer to Figure 2As shown, during operation, the pressure difference △P23 between P2 and P3 is determined. When the pressure difference △P23 between P2 and P3 is greater than the first difference P11, the operating frequency of the first-stage variable frequency dust collector 420 is increased; when the pressure difference △P34 between P3 and P4 is greater than the second difference P12, the operating frequency of the second-stage variable frequency dust collector 440 is increased. That is, in order to separate dust and air, the greater the working frequency of the variable frequency dust collector, the higher the processing rate, and the greater the ability to separate dust and air. When the amount of dust is large, the resistance will increase, resulting in an increase in the pressure difference. Therefore, the frequency of the variable frequency dust collector is controlled to control the pressure.

[0061] Among them, the dust in the pipeline is a variable, and the dust concentration will affect the conveying pressure and the pressure of the variable frequency dust collector. Once the pressure is high, it will have a great impact on the operation of the fan. Therefore, the present invention sets a first-level variable frequency dust collector 420 and a second-level variable frequency dust collector 440 to prevent dust from being mixed in the reflux gas to avoid damage to the fan. At the same time, the frequency of the variable frequency dust collector is controlled to control the pressure, so that the first-level fan unit 200 uses a low-pressure fan (such as a Roots blower) to meet the material transportation requirements and achieve energy saving.

[0062] In this way, the pressure loss caused by bag filtration in the variable frequency dust collector can be compensated. When the operating frequency of the variable frequency dust collector has reached the maximum and the pressure difference is still greater than the preset difference, an abnormal signal is output to remind the operator to repair it. After the repair, the operating frequency is reset, so that the variable frequency dust collector can run energy-savingly while meeting the pressure control requirements.

[0063] The nitrogen supply unit 100 is connected to the air inlet side of the primary blower unit 200 through a pipeline to supply and replenish nitrogen for the nitrogen circulation loop.

[0064] In a preferred embodiment, in the system configuration, a ventilation unit 600 is further configured on the air inlet side of the first-level fan unit 200, and the ventilation unit 600 includes a first adjustable ventilation valve 630, a second adjustable ventilation valve 620 and a third check valve 610. The first adjustable ventilation valve 630 is connected in series in the nitrogen circulation loop to stop or adjust the gas in the nitrogen circulation loop. The second adjustable ventilation valve 620 and the third check valve 610 are connected to the atmosphere end 620 in sequence. The second adjustable ventilation valve 620 is used to discharge part of the gas in the nitrogen circulation loop, and the third check valve 610 is used to stop the air to prevent air in the atmosphere from entering the nitrogen circulation loop. A nitrogen concentration detection sensor 960 is set on the air outlet side of the secondary variable frequency dust collector 440 to monitor the reflux nitrogen concentration K of the nitrogen circulation loop.

[0065] The steps also include an air pressure field establishment step and a nitrogen replacement step.

[0066] Among them, the steps for establishing the air pressure field are: closing the nitrogen supply unit 100, opening the first adjustable ventilation valve 630 in the ventilation unit 600, closing the adjustable ventilation valve 620, and opening the first-level fan unit 200. When P1>P2>P3>P4>P5, it means that the gas circulation is realized and the pressure direction is from high to low. At this time, the air pressure field is established, and then the nitrogen replacement step is entered.

[0067] That is, before starting the powder conveying, first close the nitrogen supply unit 100, and only use the original air in the system to establish the air pressure field of the ventilation unit to verify whether the nitrogen circulation loop can work normally, whether there is pressure leakage, blockage, etc., eliminate the abnormality, and after establishing the air pressure field, enter the nitrogen replacement step.

[0068] The nitrogen replacement step is as follows: close the first adjustable ventilation valve 630 in the ventilation unit 600, open the second adjustable ventilation valve 620 and the first-level fan unit 200, turn on the nitrogen supply unit 100, maintain P1>P2>P3>P4, and replace the air; when the nitrogen concentration detection sensor 960 detects that the nitrogen concentration K is greater than the replacement concentration threshold KH, end the nitrogen replacement, close the second adjustable ventilation valve 620, open the first adjustable ventilation valve 630, enter the aforementioned feeding control step, turn on the first-level fan unit 200 and the conveying unit 300 to supply powder, and feed with nitrogen gas flow.

[0069] In a preferred embodiment, it also includes an operation monitoring step, at which the controller performs nitrogen concentration detection replacement and nitrogen flow detection replacement respectively.

[0070] In the nitrogen concentration detection replacement, the controller is configured to open the nitrogen supply unit 100 to replenish nitrogen when the nitrogen concentration K is less than the replenishment concentration threshold K1, and close the nitrogen supply unit 100 when K=KH; start the nitrogen replacement step when the nitrogen concentration K is less than the replacement concentration threshold K2; wherein K1>K2.

[0071] In a preferred embodiment, the system is configured to configure a first flow meter 980 and an adjustable air replenishment valve 122 on the air outlet side of the nitrogen supply unit 100. The first flow meter 980 is used to monitor the output flow rate Q1 of the nitrogen supply unit 100. In this way, the adjustable air replenishment valve 122 controls the output flow rate and speed of the nitrogen supply unit 100 until the nitrogen supply unit 100 is closed when K=KH. The first flow meter 980 is used to monitor the output flow rate Q1 of the nitrogen supply unit 100 to complete the air replenishment.

[0072] In a more preferred embodiment, in order to increase the air replenishment speed so that the nitrogen concentration meets the operating requirements as soon as possible, the controller also controls the second adjustable ventilation valve 620 to discharge a part of the insufficient concentration to increase the overall nitrogen concentration. When the nitrogen concentration K=KH, the replacement is stopped.

[0073] That is, if the air replenishment speed is too fast, it will cause system fluctuations and destroy the pressure field. Therefore, in the present application, the adjustable air replenishment valve 122 is an electrically controlled adjustable air replenishment valve, and the air replenishment speed is controlled by controlling its opening. At the same time, the first adjustable ventilation valve 630 and the second adjustable ventilation valve 620 are also electrically controlled adjustable valves. Adjusting the opening of the second adjustable ventilation valve 620 can discharge low-concentration airflow. The faster the replacement speed is required, the larger the opening is. Adjusting the opening of the first adjustable ventilation valve 630 can control the local resistance. The larger the local resistance is required, the smaller the opening is. Therefore, the ventilation efficiency can be improved by adjusting the first adjustable ventilation valve 630 and the second adjustable ventilation valve 620.

[0074] In addition, when the amount of nitrogen added exceeds the limit, the excess nitrogen will inevitably cause the pressure to rise. After the second adjustable ventilation valve 620 is opened, the check valve 610 will also automatically open under pressure to discharge the excess pressure. At this time, the check valve 610 acts as a safety valve.

[0075] In the nitrogen flow detection replacement, the system is also equipped with a second flow meter 990 on the air outlet side of the secondary variable frequency dust collector 440 to monitor the reflux nitrogen flow Q2 of the nitrogen circulation loop; at this time, the controller is also configured to obtain the reflux nitrogen flow Q2, and when the nitrogen flow Q2 is less than the set value Q, the adjustable air supply valve is opened to supply air, and the air supply amount is k (Q-Q2), where k is a safety factor greater than 1.

[0076] At the same time, since all pipeline systems are positive pressure systems, some leakage will occur. Therefore, the gas source supplements nitrogen when nitrogen leaks in the pipeline system. That is, when P5 is less than the set threshold P13, the controller turns on the nitrogen supply unit 100 to supplement nitrogen. The gas replenishment strategy is executed according to the nitrogen flow detection and replacement strategy, that is, the flow is supplemented to increase the pressure.

[0077] In addition, the value of Q2 is an instantaneous value, which can be used to determine the instantaneous flow value in the current pipeline, while the value of Q1 is a value within a certain time interval. Therefore, whether the leakage of the system is normal can be determined by whether the change of Q1 within a certain period of time is abnormal; therefore, Q1 is also used to measure the economy and energy consumption of the system operation.

[0078] The subsequent steps also include a filter tank unloading step. The ash volume of the primary filter tank 410 is greater than the ash volume of the secondary filter tank 430, and the capacity of the primary filter tank 410 is configured to be greater than the capacity of the secondary filter tank 430. When the primary filter tank 410 reaches the material level meter X, the controller controls the primary filter tank 410 to start unloading to the terminal bin 500; when the ash volume of the secondary filter tank 430 reaches the material level meter Z, the controller controls the secondary filter tank 430 to start unloading to the terminal bin 500. In order to ensure that the terminal bin 500 has powder supply at any time, the controller controls the primary filter tank 410 and the secondary filter tank 430 to unload in time, that is, at any time, the primary filter tank 410 and the secondary filter tank 430 do not unload at the same time.

[0079] In a preferred embodiment, please refer to Figure 1 As shown, when the distance between the secondary variable frequency dust collector 440 and the primary fan unit 200 is greater than a certain value, a secondary fan unit 800 is arranged in front of the primary fan unit 200, and the secondary fan unit 800 is used to compensate for the resistance of the pipeline and valve of the nitrogen circulation loop. That is, the conveying unit 300 and the terminal warehouse 500 are not arranged nearby, and the pressure generated by the primary fan unit 200 of this system can be used at a distance of about 100 meters, and the distance of the return pipe from the dust collector outlet can reach 100 meters or even more. However, both the pipeline and the elbow will generate resistance, and the resistance generated cannot be ignored. When the distance is too large, the resistance is compensated by the secondary fan unit 800 to achieve smooth feeding.

[0080] Example 2

[0081] The present invention discloses an energy-saving cyclic conveying system for executing the energy-saving cyclic conveying method as described in Example 1.

[0082] Among them, please refer to Figure 1 As shown, the system includes a primary fan unit 200, a conveying unit 300, a primary filter tank 410, a primary variable frequency dust collector 420, a secondary filter tank 430, a secondary variable frequency dust collector 440, a terminal bin 500, a sensor group and a controller.

[0083] The primary fan unit 200, the conveying unit 300, the primary filter tank 410, the primary variable frequency dust collector 420, the secondary filter tank 430, and the secondary variable frequency dust collector 440 are connected in sequence to form a nitrogen circulation loop, and the terminal warehouse 500 is connected to the discharge ends of the primary filter tank 410 and the secondary filter tank 430.

[0084] The sensor group includes a first pressure gauge 910, a second pressure gauge 920, a third pressure gauge 930, a fourth pressure gauge 940, a fifth pressure gauge 950, a nitrogen concentration detection sensor 960, a thermometer 970, a first flow meter 980 and a second flow meter 990. The first pressure gauge 910 is connected in series to the air outlet side of the primary fan unit 200, the second pressure gauge 920 is connected in series to the air inlet side of the primary filter tank 410, the third pressure gauge 930 is connected in series to the air outlet side of the primary variable frequency dust collector 420, the fourth pressure gauge 940 is connected in series to the air outlet side of the secondary variable frequency dust collector 440, and the fifth pressure gauge 950 is connected in series to the air inlet side of the primary fan unit 200. The nitrogen concentration detection sensor 960 is arranged on the air outlet side of the secondary variable frequency dust collector 440, the thermometer 970 is arranged on the front side of the primary fan unit 200, the first flow meter 980 is arranged on the air outlet side of the nitrogen supply unit 100, and the second flow meter 990 is arranged on the air outlet side of the secondary variable frequency dust collector 440.

[0085] Among them, please refer to Figure 7 As shown, the nitrogen supply unit 100 includes a high-pressure gas tank 110 and a low-pressure gas tank 120. The inlet of the high-pressure gas tank 110 is connected to the high-pressure nitrogen used in the factory. The outlet of the high-pressure gas tank 110 is connected in series with a first check valve 111 and a first pressure regulating valve 112 in sequence, and then connected to the inlet of the low-pressure gas tank 120. The outlet of the low-pressure gas tank 120 is connected in series with a second pressure regulating valve 121 and an adjustable air supply valve 122 in sequence, and then connected to the inlet of the first-stage fan unit 200.

[0086] Among them, the pressure of nitrogen after separation by air separator is currently very high (1MPa), and the pressure of nitrogen supply in the factory area (above 0.7MPa) is much higher than the pressure of the fan (below 0.1MPa). To supplement the pressure, not only the pressure but also the gas flow rate is needed. If the pressure before and after the pressure regulating valve is adjusted too much, the gas flow will be insufficient. At the same time, valve failure is also likely to directly affect the entire system. Therefore, this embodiment realizes secondary pressure reduction by setting a high-pressure gas storage tank 110 and a low-pressure gas storage tank 120 to prevent high-pressure nitrogen from entering the system due to failure, thereby ensuring safety.

[0087] After being connected in series with the second check valve 210 , the primary fan unit 200 is connected to the delivery unit 300 to supply air to the delivery unit 300 .

[0088] Please refer to Figure 8As shown, the conveying unit 300 includes an ash hopper 310, an ash hopper discharge valve 320, a collection tank 330, a discharge valve 340, an electric discharger 350 and an ash-gas combiner 360 connected in sequence. An ash hopper balance valve 370 is provided between the ash hopper 310 and the collection tank 330, which is used to discharge the residual pressure in the collection tank 330 to the ash hopper 310 through the exhaust valve during the discharge process of the ash hopper 310. The powder in the ash hopper 310 enters the collection tank 330 from the discharge valve by its own weight to ensure smooth discharge. The ash-gas combiner 360 is used to connect the fan unit, and the electric discharger 350 is used to control the powder to flow from the collection tank 330 to the ash-gas combiner 360 to achieve mixing and transportation of gas and powder.

[0089] Please refer to Fig. 9 As shown, the first-level filter tank 410 discharges to the terminal warehouse 500 through the first unloading valve 411, and the first balancing valve 412 balances the pressure between the first-level filter tank 410 and the terminal warehouse 500 to facilitate smooth unloading; the second-level filter tank 430 discharges to the terminal warehouse 500 through the second-level unloading valve 340, and the second balancing valve 432 balances the pressure between the second-level filter tank 430 and the terminal warehouse 500 to facilitate smooth unloading.

[0090] The ventilation unit 600 is arranged between the secondary variable frequency dust collector 440 and the primary fan unit 200, and is connected to the nitrogen circulation loop through the third check valve 610 and the second adjustable ventilation valve 620 connected in series in sequence. The first adjustable ventilation valve 630 is arranged in the nitrogen circulation loop. Along the gas conveying direction, the nitrogen concentration detection sensor K and the first adjustable ventilation valve 630 are arranged on both sides of the ventilation unit 600. In this way, when the air pressure field is established, the first adjustable ventilation valve 630, the first-level fan unit 200, the first-level variable frequency dust collector 420 and the second-level variable frequency dust collector 440 are opened in sequence until P1>P2>P3>P4>P5, and the air pressure field is established; and when nitrogen replacement is performed, the first-level fan unit 200 is continuously opened, the first adjustable ventilation valve 630 is closed, and the second adjustable ventilation valve 620 and the adjustable air supply valve 122 are opened in sequence until the preset nitrogen concentration is reached, and the second adjustable ventilation valve 620 and the adjustable air supply valve 122 are closed, and the first adjustable ventilation valve 630 is opened to end the nitrogen replacement.

[0091] The secondary fan unit 800 is arranged between the ventilation unit 600 and the primary fan unit 200. The secondary fan unit 800 is a micro-boosting unit, which is used to compensate for the resistance of the pipes and valves of the nitrogen circulation loop when the distance between the secondary variable frequency dust collector 440 and the fan unit is greater than a certain value.

[0092] In a preferred embodiment, please refer to Figure 1As shown, a thermometer 970 and a gas refrigeration dryer 700 are also provided in the nitrogen circulation loop. The thermometer 970 and the gas refrigeration dryer 700 are respectively arranged on the front side of the primary fan unit 200 to monitor the temperature of the reflux gas, and control the gas refrigeration dryer 700 to adjust the gas temperature and dry the gas, balance the heat generated by the equipment due to the transportation process, maintain the stability of the system, dry the gas in the process of temperature change during refrigeration, and avoid possible chemical reaction between moisture and powder (such as aluminum powder reacting with water to generate dangerous gas).

[0093] When the system stops running, the conveying unit 300, the secondary fan unit 800, the primary fan unit 200, the gas refrigeration dryer 700 and the valve equipment are turned off in sequence, and the primary variable frequency dust collector 420 and the secondary variable frequency dust collector 440 are shut down to complete the operation.

[0094] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An energy-saving circulation transportation method, characterized in that: include: System configuration: The primary fan unit, the conveying unit, the primary filter tank, the primary variable frequency dust collector, the secondary filter tank, and the secondary variable frequency dust collector are connected in sequence by pipelines to form a nitrogen circulation loop, and the terminal bin is connected to the discharge ends of the primary filter tank and the secondary filter tank; the primary fan unit is a Roots blower, a first pressure gauge is arranged on the air outlet side of the primary fan unit to monitor the pressure value P1, a second pressure gauge is arranged on the air inlet side of the primary filter tank to monitor the pressure value P2, a third pressure gauge is arranged on the air outlet side of the primary variable frequency dust collector to monitor the pressure value P3, a fourth pressure gauge is arranged on the air outlet side of the secondary variable frequency dust collector to monitor the pressure value P4, and a fifth pressure gauge is arranged on the air inlet side of the primary fan unit to monitor the pressure value P5; A nitrogen supply unit is configured, and the pipeline of the nitrogen supply unit is connected to the air inlet side of the primary fan unit to supply and replenish nitrogen for the nitrogen circulation loop; a ventilation unit is configured on the air outlet side of the secondary variable frequency dust collector, and the ventilation unit includes a first adjustable ventilation valve, a second adjustable ventilation valve and a third check valve, the first adjustable ventilation valve is connected in series in the nitrogen circulation loop, and the second adjustable ventilation valve and the third check valve are connected to the atmosphere end in sequence; a nitrogen concentration detection sensor is set on the air outlet side of the secondary variable frequency dust collector to monitor the reflux nitrogen in the nitrogen circulation loop. concentration K; a first flowmeter and an adjustable air supply valve are arranged on the air outlet side of the nitrogen supply unit, the first flowmeter monitors the output flow Q1 of the nitrogen supply unit, and the adjustable air supply valve controls the output flow of the nitrogen supply unit; a second flowmeter is arranged on the air outlet side of the secondary variable frequency dust collector to monitor the reflux nitrogen flow Q2 of the nitrogen circulation loop; a gas refrigeration dryer is arranged at the front end of the primary fan unit, and a thermometer is arranged at the front end of the gas refrigeration dryer to monitor the reflux gas temperature TX of the nitrogen circulation loop; Feeding control: The controller obtains the pressure values ​​obtained by each pressure gauge, controls the operation of the first-level fan unit, and maintains P1>P2>P3>P4>P5; determines whether the pressure difference △P23 between P2 and P3 is greater than the first difference, if so, increases the operating frequency of the first-level variable frequency dust collector until △P23 is less than the first difference, if not, maintains the current operating frequency of the first-level variable frequency dust collector; determines whether the pressure difference △P34 between P3 and P4 is greater than the second difference, if so, increases the operating frequency of the second-level variable frequency dust collector until △P34 is less than the second difference, if not, maintains the current operating frequency of the second-level variable frequency dust collector; Operation monitoring steps: nitrogen replenishment and nitrogen replacement are performed when the nitrogen concentration is insufficient, the nitrogen pressure is insufficient, or the nitrogen is lost; when the nitrogen supply unit is opened to replenish nitrogen when the nitrogen concentration K is less than the replenishment concentration threshold K1, the nitrogen amount Qb to be injected is calculated according to the nitrogen concentration K, the adjustable air replenishment valve is opened to replenish air, and the injected nitrogen is measured by the first flow meter; the second adjustable ventilation valve is opened at a certain opening, and the opening of the first adjustable ventilation valve is reduced at the same time, until K=KH, the adjustable air replenishment valve and the second adjustable ventilation valve are closed, and the opening of the first adjustable ventilation valve is restored; when the nitrogen concentration K When the nitrogen concentration is less than the replacement concentration threshold value K2, the nitrogen replacement step is started; wherein K1>K2; the controller is further configured to obtain the reflux nitrogen flow rate Q2, and when the nitrogen flow rate Q2 is less than the set value Q, the adjustable air supply valve is opened to supply air, and the air supply amount is k (Q-Q2), where k is a safety factor greater than 1; the nitrogen replacement step is: opening the ventilation unit, opening the nitrogen supply unit, maintaining P1>P2>P3>P4, and replacing air; when the nitrogen concentration detection sensor detects that the nitrogen concentration K reaches the replacement concentration threshold value KH, the ventilation unit is closed to end the nitrogen replacement; The controller is configured with a temperature lower limit value T1 and a temperature upper limit value T2. When T1<TX<T2, the controller controls the gas refrigeration dryer to stop; when TX>T2, the controller controls the gas refrigeration dryer to start, and the gas refrigeration dryer is turned off when TX<T1.

2. The energy-saving circulation transportation method according to claim 1, characterized in that: Also included is an air pressure field establishment step; The air pressure field establishment step is: closing the nitrogen supply unit, opening the primary blower unit, and when P1>P2>P3>P4>P5, the air pressure field establishment is completed and the nitrogen replacement step is entered.

3. The energy-saving circulation transportation method according to claim 1, characterized in that: It also includes a filter tank unloading step: configuring the capacity of the first-level filter tank to be larger than the capacity of the second-level filter tank, and when the ash amount in the first-level filter tank / second-level filter tank reaches the level meter alarm, the controller controls the first-level filter tank / second-level filter tank to start unloading to the terminal warehouse; the controller controls the first-level filter tank and the second-level filter tank to unload in a time-sharing manner.

4. An energy-saving circulation conveying system, characterized in that: include: Primary fan unit, conveying unit, primary filter tank, primary variable frequency dust collector, secondary filter tank, secondary variable frequency dust collector, terminal bin, sensor group, nitrogen supply unit, ventilation unit and controller; The primary fan unit, the conveying unit, the primary filter tank, the primary variable frequency dust collector, the secondary filter tank, and the secondary variable frequency dust collector are connected in sequence to form a nitrogen circulation loop, and the terminal bin is connected to the discharge ends of the primary filter tank and the secondary filter tank; The sensor group includes a first pressure gauge, a second pressure gauge, a third pressure gauge, a fourth pressure gauge and a fifth pressure gauge, the first pressure gauge is connected in series to the air outlet side of the first-level fan unit, the second pressure gauge is connected in series to the air inlet side of the first-level filter tank, the third pressure gauge is connected in series to the air outlet side of the first-level variable frequency dust collector, the fourth pressure gauge is connected in series to the air outlet side of the second-level variable frequency dust collector, and the fifth pressure gauge is connected in series to the air inlet side of the first-level fan unit; The nitrogen supply unit is connected to the air inlet side of the primary fan unit, and is started to replenish air when the nitrogen concentration or nitrogen flow in the nitrogen circulation loop is insufficient; the nitrogen supply unit includes a high-pressure gas storage tank and a low-pressure gas storage tank, the inlet of the high-pressure gas storage tank is connected to the factory nitrogen, the outlet of the high-pressure gas storage tank is connected in series with the first check valve and the first pressure regulating valve in sequence, and then connected to the inlet of the low-pressure gas storage tank, and the outlet of the low-pressure gas storage tank is connected in series with the second pressure regulating valve and the adjustable air replenishment valve in sequence, and then connected to the inlet of the primary fan unit; The ventilation unit is connected to the air inlet side of the primary fan unit and is used to discharge part of the gas in the pipeline when replacing nitrogen; The controller executes the method according to claim 1.

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