A pneumatic conveying system and method

Abstract

The application relates to the technical field of material conveying, and discloses a pneumatic conveying system and method. The system comprises a fluidization chamber, a conveying pipeline, a primary gas and an auxiliary blowing gas inlet pipeline, the conveying pipeline is communicated with the fluidization chamber, the primary gas inlet pipeline is communicated with the fluidization chamber, and the auxiliary blowing gas inlet pipeline is communicated with the conveying pipeline. The method comprises the following steps: acquiring conveying pressure and system output of the pneumatic conveying system; and adjusting the inlet flow of the primary gas and the auxiliary blowing gas inlet pipeline according to the conveying pressure and the system output, so that the system conveying pressure reaches a preset conveying pressure range and the system output reaches a preset system output range. Through cooperation of the two inlets of the primary gas and the auxiliary blowing gas, the system and the method can make the material and the gas more uniformly mixed, the pipeline is not prone to being blocked, and through cooperative adjustment of the inlet flow of the two inlets, the inlet flow of the fluidization chamber and the conveying pipeline is cooperatively adjusted, the requirement of conveying gas flow for material property change can be met, and the system energy consumption and the conveying pipeline abrasion are reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of material conveying, in particular to a pneumatic conveying system and method. BACKGROUND

[0002] The pneumatic conveying system is a fully-closed pipeline conveying system using the principle of gas-solid two-phase flow and compressed air as medium and power to convey powdery materials to a remote collection point. It is widely used in various industries due to its flexible arrangement, no secondary pollution, high efficiency, energy saving, convenience in material conveying and recycling, etc.

[0003] In the pneumatic conveying process, the material parameters such as particle size distribution, bulk density, moisture content, etc. of the conveyed material may change. Different materials require different conveying air volume. For example, coarse and heavy materials require a larger conveying air volume, which reduces the conveying air ratio, and in the case of the same pipe diameter and the same conveying distance, the conveying output is smaller. The traditional pneumatic conveying method generally adjusts the air inlet volume of the air inlet path first, and then conveys the material while ensuring that the air inlet volume of the air inlet path remains unchanged. This method cannot intelligently adjust and optimize the air inlet volume according to the change of the material properties, and it is difficult to adapt to the requirements of the conveying air volume due to the change of the material properties. For example, if the material density becomes larger, a larger air inlet volume is required, and if the original air inlet volume remains unchanged, it is easy to cause pipe blockage. If the material density becomes smaller, a smaller air inlet volume is required, and if the original air inlet volume remains unchanged, it will increase the energy consumption of the conveying system and the wear of the conveying pipeline.

[0004] In the prior art, the air inlet volume is adjusted in real time according to the conveying pressure. For example, the Chinese patent with the authorization announcement number CN100453430C discloses an energy-saving method and device for a powder and particle material pneumatic conveying system. The bin pump is provided with an air inlet pipeline, a flow regulating device is arranged on the air inlet pipeline, and a bin pressure sensor is arranged in the bin pump. The flow regulating device automatically adjusts the flow of compressed air according to the pressure change in the bin pump until the pressure in the bin pump reaches the allowable error range of the set value, so as to achieve the purpose of energy saving. However, the air inlet pipeline has only one way, and the air inlet flow of the bin pump can only be adjusted according to the bin pump pressure. The mixture of the material is not uniform, it is easy to block the pipe, and the system energy consumption and pipeline wear are still high.

[0005] It can be seen that the existing pneumatic conveying method has only one air inlet pipeline and can only adjust the air inlet flow of the bin pump according to the bin pump pressure. It is easy to block the pipe, and the system energy consumption and pipeline wear are still high. SUMMARY

[0006] The purpose of the present application is to provide a pneumatic conveying system, which can make the mixing of material and gas more uniform and not prone to pipe blockage by the cooperation of two air inlet paths of primary air and auxiliary blowing air, and can adapt to the requirement of conveying air volume for material property changes, reduce system energy consumption and conveying pipeline wear by cooperatively adjusting the air inlet flow of the two air inlet pipelines.

[0007] To solve the above technical problems, the present application provides a pneumatic conveying system, which comprises a fluidization chamber and a conveying pipeline, the feeding end of the conveying pipeline is communicated with the discharging port of the fluidization chamber, and further comprises a primary air inlet pipeline and an auxiliary blowing air inlet pipeline.

[0008] The air outlet of the primary air inlet pipeline is communicated with the fluidization chamber, and the air outlet of the auxiliary blowing air inlet pipeline is communicated with the conveying pipeline.

[0009] The pneumatic conveying system provided by the present application sets the fluidization chamber and the conveying pipeline in communication, sets the primary air inlet pipeline in communication with the fluidization chamber, and sets the auxiliary blowing air inlet pipeline in communication with the conveying pipeline, so that the material in the fluidization chamber can be fluidized by the primary air, and the material entering the conveying pipeline can be further mixed and conveyed by the auxiliary blowing air. Through the cooperation of the two air inlet paths, the mixing of material and gas can be more uniform and not prone to pipe blockage, and the air inlet flow of the two air inlet pipelines can be cooperatively adjusted to cooperatively adjust the air inlet flow of the fluidization chamber and the conveying pipeline, so as to adapt to the requirement of conveying air volume for material property changes, reduce system energy consumption and conveying pipeline wear.

[0010] Optionally, the pneumatic conveying system further comprises a pressure detection device.

[0011] The pressure detection device is arranged in the fluidization chamber or the conveying pipeline, and is used for detecting the conveying pressure of the fluidization chamber or the conveying pipeline, and adjusting the air inlet flow of the primary air inlet pipeline and the auxiliary blowing air inlet pipeline according to the conveying pressure detected by the pressure detection device.

[0012] Optionally, the primary air inlet pipeline and the auxiliary blowing air inlet pipeline are respectively provided with a primary air regulating valve and an auxiliary blowing air regulating valve, and adjusting the opening degree of the primary air regulating valve or the auxiliary blowing air regulating valve can adjust the air inlet flow of the corresponding air inlet pipeline.

[0013] Optionally, the pneumatic conveying system further comprises an air blower.

[0014] The auxiliary blower is arranged on the conveying pipeline, and the air outlet of the auxiliary air inlet pipeline is communicated with the auxiliary blower.

[0015] Optionally, the gas source is further included.

[0016] The primary air inlet pipeline and the auxiliary air inlet pipeline are both communicated with the gas source.

[0017] Optionally, the silo is further included.

[0018] The fluidization chamber is a silo pump or a mixing chamber communicated below the silo pump, and the discharge port of the silo is communicated with the feeding port of the silo pump.

[0019] Optionally, the material weighing device and / or the solid flow measuring instrument are further included.

[0020] The material weighing device is used for weighing the mass of the material conveyed by the fluidization chamber to the conveying pipeline, and the material conveying mass measured by the material weighing device can be used for calculating the system output of the pneumatic conveying system.

[0021] The solid flow measuring instrument is used for measuring the material conveying flow of the conveying pipeline, and the material conveying flow measured by the solid flow measuring instrument can be used for calculating the system output of the pneumatic conveying system.

[0022] The air inlet flow of the primary air inlet pipeline and the auxiliary air inlet pipeline is adjusted according to the calculated system output.

[0023] The application further provides a pneumatic conveying method, which uses the pneumatic conveying system to convey materials, and includes the following steps.

[0024] A data acquisition step is provided for acquiring the conveying pressure and the system output of the pneumatic conveying system.

[0025] An air inlet flow adjustment step is provided for adjusting the air inlet flow of the primary air inlet pipeline and the auxiliary air inlet pipeline according to the acquired conveying pressure and system output, so that the conveying pressure of the pneumatic conveying system reaches the preset conveying pressure range and the system output reaches the preset system output range.

[0026] The pneumatic conveying method provided by the application adjusts the air inlet flow of the primary air inlet pipeline and the auxiliary air inlet pipeline according to the conveying pressure and the system output of the pneumatic conveying system, so that the conveying pressure of the pneumatic conveying system reaches the preset conveying pressure range and the system output reaches the preset system output range. In this way, the air inlet flow of the fluidization chamber and the air inlet flow of the conveying pipeline can be coordinately adjusted by comprehensively considering various factors and adjusting the air inlet flow of the two air inlets, so that the adjusted air inlet flow can adapt to the requirement of the conveying air flow caused by the change of the material properties, the conveying pipeline is not easy to be blocked, and the system energy consumption and the conveying pipeline wear are reduced.

[0027] Optionally, a primary gas regulating valve and an auxiliary gas regulating valve are respectively provided on the primary gas inlet pipe and the auxiliary gas inlet pipe;

[0028] The data acquisition step further includes: acquiring the total air volume Q of the pneumatic conveying system, the opening degree K of the blowing air regulating valve, and the design output B. s Preset upper limit value of conveying pressure P g Preset minimum value of total gas delivery volume Q min Preset upper limit of total gas delivery volume Q max The opening adjustment range R1 of the primary gas regulating valve and the opening adjustment range R2 of the auxiliary blowing gas regulating valve; wherein, the conveying pressure is the highest conveying pressure of the pneumatic conveying system in the previous period;

[0029] The intake airflow adjustment steps specifically include:

[0030] Compare the system output B in the previous period with the design output B. s Maximum conveying pressure P and upper limit value of conveying pressure P g ,

[0031] When B≥B s And P≤P g At that time, determine whether K is equal to 0. If K ≠ 0, reduce the opening of the primary gas regulating valve by R1 and reduce the opening of the auxiliary blowing gas regulating valve by R2. If K = 0, continue to compare Q with Q min If Q≤Q min Then keep the opening of the primary gas regulating valve unchanged. If Q > Q min Then reduce the opening of the primary gas regulating valve by an amount of R1; and / or,

[0032] When B > B s And P > P g At the same time, the opening of the primary gas regulating valve is reduced by an amount of R1, and the opening of the auxiliary blowing gas regulating valve is increased by an amount of R2; and / or,

[0033] When B < B s And P < P g At that time, determine whether K is equal to 0. If K ≠ 0, increase the opening of the primary gas regulating valve by R1 and decrease the opening of the auxiliary blowing gas regulating valve by R2. If K = 0, continue to compare Q with Q. max If Q max Then increase the opening of the primary gas regulating valve by an amplitude of R1. If Q ≥ Q max The system then enters a fault self-test and outputs a fault alarm; and / or,

[0034] When B < B s ​and P>P g and Q>Q max , if Q max , the opening of the primary gas regulating valve is increased by R1, and the opening of the secondary gas regulating valve is increased by R2, if Q≥Q max , the system enters into fault self-checking and outputs fault alarm.

[0035] Optionally, the system output is calculated by any one of the following three ways or the average of the calculation results of any two or more ways:

[0036] When the fluidizing chamber is a bin pump or a mixing chamber communicated below the bin pump, the conveying time T of the last period is collected, and the system output B=(V*ρ*ψ) / T is calculated by combining the volume V of the bin pump, the bulk density ρ of the material, and the material filling rate ψ.

[0037] The conveying quality M and the conveying time T of the last period are collected, and the system output B=M / T is calculated.

[0038] The conveying flow rate q of the conveying pipeline in the last period is collected, and the system output B=q is calculated. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 The structural schematic diagram of the pneumatic conveying system of the embodiments provided in the present application;

[0040] Figure 2 The flowchart of the air intake amount adjustment in the pneumatic conveying method of the embodiments provided in the present application;

[0041] Figure 3 The flowchart of the system output calculation in the pneumatic conveying method of the embodiments provided in the present application.

[0042] The reference signs in the above drawings are explained as follows:

[0043] 11-bunker, 12-bin pump, 13-mixing chamber, 14-feeding valve, 15-balancing valve, 16-feeding pipeline, 17-exhaust pipeline;

[0044] 2-air source;

[0045] 31-conveying pipeline, 32-discharging valve;

[0046] 41-primary gas feeding pipeline, 42-primary gas pneumatic shut-off valve, 43-primary gas regulating valve, 44-primary gas manual ball valve, 45-primary gas check valve;

[0047] 51-secondary gas feeding pipeline, 52-secondary gas pneumatic shut-off valve, 53-secondary gas regulating valve, 54-secondary gas manual ball valve, 55-secondary gas check valve, 56-blowing device;

[0048] 6-pressure detection device;

[0049] 7-material weighing device;

[0050] 8-solid flow measuring instrument;

[0051] 9-terminal bin. DETAILED DESCRIPTION

[0052] In order to make the person skilled in the art better understand the scheme of the present application, the present application will be further described in detail below in combination with the drawings and specific embodiments.

[0053] It should be particularly pointed out that "downstream" in the present application refers to the front in the material conveying direction in the conveying pipeline 31.

[0054] In the existing pneumatic conveying mode, the bin pump is provided with one air inlet pipeline, and a flow regulating device is used to automatically regulate the flow of compressed air according to the pressure change in the bin pump. The air inlet pipeline has only one way, and only the air inlet flow of the bin pump can be regulated according to the pressure of the bin pump. The mixing of the material is not uniform enough, the pipe is easy to be blocked, and the system energy consumption and pipeline wear are high.

[0055] Therefore, the present application provides a pneumatic conveying system, which can uniformly mix the material and gas through the cooperation of two air inlets, is not easy to block the pipe, and can cooperatively regulate the air inlet flow of the two air inlet pipelines to cooperatively regulate the air inlet flow of the fluidization chamber and the conveying pipeline, so as to adapt to the requirement of the conveying air volume for the material property change, and reduce the system energy consumption and the conveying pipeline wear.

[0056] Please refer to Figure 1 , Figure 1 The structure schematic diagram of the pneumatic conveying system provided in the embodiments of the present application.

[0057] In the embodiments provided in the present application, the pneumatic conveying system comprises a fluidization chamber, a conveying pipeline 31, a primary air inlet pipeline 41 and an auxiliary blowing air inlet pipeline 51. The feeding end of the conveying pipeline 31 is in communication with the discharging port of the fluidization chamber. The air outlet of the primary air inlet pipeline 41 is in communication with the fluidization chamber. The air outlet of the auxiliary blowing air inlet pipeline 51 is in communication with the conveying pipeline 31.

[0058] In this way, the primary gas delivered by the primary gas inlet pipeline 41 can be used to fluidize the material in the fluidization chamber, and the secondary blowing gas delivered by the secondary blowing gas inlet pipeline 51 can be used to further mix and deliver the material into the delivery pipeline 31. Through the cooperation of the two gas inlets, the mixture of the material and the gas can be more uniform, the pipe blockage can be avoided, and the gas flow of the fluidization chamber and the gas flow of the delivery pipeline 31 can be adjusted in cooperation by adjusting the gas flow of the two gas inlets, so as to adapt to the requirement of the material property change on the delivery gas amount, and reduce the system energy consumption and the delivery pipeline wear.

[0059] In the embodiments provided in the present application, the pneumatic conveying system further comprises a pressure detection device 6; the pressure detection device 6 is arranged in the fluidization chamber or the delivery pipeline 31, and is used to detect the delivery pressure of the fluidization chamber or the delivery pipeline 31, and adjust the gas flow of the primary gas inlet pipeline 41 and the secondary blowing gas inlet pipeline 51 according to the delivery pressure detected by the pressure detection device 6. In this way, the gas flow of the fluidization chamber and the gas flow of the delivery pipeline 31 can be adjusted in cooperation according to the delivery pressure of the pneumatic conveying system, the pipe blockage phenomenon can be reduced, and the system energy consumption and the delivery pipeline wear can be reduced.

[0060] In actual use, the pressure detection device 6 can be arranged on the fluidization chamber to measure the pressure inside the fluidization chamber, and the gas flow of the two gas inlets can be adjusted according to the pressure inside the fluidization chamber. Figure 1 As shown in FIG. 6, the pressure detection device 6 can be arranged on the delivery pipeline 31 and located downstream of the secondary blowing gas inlet pipeline 51. At this time, the pressure detection device 6 can be a pressure transmitter, the delivery pressure of the material blown by the secondary blowing gas in the delivery pipeline 31 is measured by using the pressure detection device 6, and the gas flow of the two gas inlets is adjusted according to the delivery pressure of the delivery pipeline 31. It can be understood that when the material property becomes coarse and heavy, the pressure in the fluidization chamber can be blocked to cause a higher chamber pressure in the fluidization chamber and a smaller pipe pressure in the delivery pipeline 31. If the pipe blockage is judged according to the chamber pressure in the fluidization chamber, the judgment can be wrong. Obviously, at this time, the pipe pressure in the delivery pipeline 31 can reflect the real material property change more than the pressure inside the fluidization chamber, and the gas flow of the two gas inlets can be adjusted by using the pipe pressure in the delivery pipeline 31, so that the adjusted gas flow can be more adaptive to the material property change.

[0061] It can be understood that the adjustment mode of the gas flow of the primary gas inlet pipeline 41 and the secondary blowing gas inlet pipeline 51 is not limited. For example, the gas flow of the two can be adjusted by adjusting the supply power of the gas source connected to the two, and the gas flow of the two can be adjusted by adjusting the supply power of the gas source connected to the two. Figure 1As shown, the primary air regulating valve 43 and the secondary air regulating valve 53 are arranged on the primary air inlet pipeline 41 and the secondary air inlet pipeline 51 respectively, the air flow of the primary air inlet pipeline 41 is regulated by adjusting the opening of the primary air regulating valve 43, and the air flow of the secondary air inlet pipeline 51 is regulated by adjusting the opening of the secondary air regulating valve 53, so that the operation is convenient and the regulation efficiency is high.

[0062] In the embodiments provided in the present application, the pneumatic conveying system further comprises a secondary air blower 56, the secondary air blower 56 is arranged on the conveying pipeline 31, and the air outlet of the secondary air inlet pipeline 51 is communicated with the secondary air blower 56. In this way, the secondary air blower 56 can provide a larger remixing space for the material conveyed in the conveying pipeline 31, and under the action of the secondary air provided by the secondary air inlet pipeline 51, the solid-gas mixture is more sufficient and uniform, so that the material and the gas form a more stable solid-gas two-phase flow, and the subsequent conveying is more smooth.

[0063] In the embodiments provided in the present application, the pneumatic conveying system further comprises a secondary air blower 56, the secondary air blower 56 is arranged on the conveying pipeline 31, and the air outlet of the secondary air inlet pipeline 51 is communicated with the secondary air blower 56. In this way, the secondary air blower 56 can provide a larger remixing space for the material conveyed in the conveying pipeline 31, and under the action of the secondary air provided by the secondary air inlet pipeline 51, the solid-gas mixture is more sufficient and uniform, so that the material and the gas form a more stable solid-gas two-phase flow, and the subsequent conveying is more smooth. Figure 1 As shown, the primary air regulating valve 43 and the secondary air regulating valve 53 are arranged on the primary air inlet pipeline 41 and the secondary air inlet pipeline 51 respectively, the air flow of the primary air inlet pipeline 41 is regulated by adjusting the opening of the primary air regulating valve 43, and the air flow of the secondary air inlet pipeline 51 is regulated by adjusting the opening of the secondary air regulating valve 53, so that the operation is convenient and the regulation efficiency is high.

[0064] In the embodiments provided in the present application, the pneumatic conveying system further comprises a secondary air blower 56, the secondary air blower 56 is arranged on the conveying pipeline 31, and the air outlet of the secondary air inlet pipeline 51 is communicated with the secondary air blower 56. In this way, the secondary air blower 56 can provide a larger remixing space for the material conveyed in the conveying pipeline 31, and under the action of the secondary air provided by the secondary air inlet pipeline 51, the solid-gas mixture is more sufficient and uniform, so that the material and the gas form a more stable solid-gas two-phase flow, and the subsequent conveying is more smooth.

[0065] It can be understood that the fluidization chamber can be one or multiple and connected in series, as long as the fluidization and conveying of the material can be realized, and the present application does not limit this.

[0066] In the embodiments provided in the present application, the fluidization chamber is one, the top of the bin pump 12 is communicated with the bottom of the material bin 11, the bottom of the bin pump 12 is communicated with the top of the mixing chamber 13, the air inlet of the mixing chamber 13 is communicated with the primary air inlet pipeline 41, the material outlet of the mixing chamber 13 is communicated with the feeding end of the conveying pipeline 31, and the discharging end of the conveying pipeline 31 is communicated with the terminal bin 9. The material bin 11 sends the material to be conveyed into the bin pump 12, the material enters the mixing chamber 13 through the bin pump 12, mixes with the primary air sent by the primary air inlet pipeline 41 in the mixing chamber 13, realizes the fluidization of the material, and then the fluidized material is sent into the snifter 56 through the conveying pipeline 31, the snifter 56 sends the snifting air into the snifter 56 through the snifting air inlet pipeline 51, the material is further mixed, and then the material is conveyed to the terminal bin 9 through the conveying pipeline 31.

[0067] Please refer to Figure 1 The embodiments provided in the present application also set various valves for multi-aspect control. For example, the bottom of the material bin 11 and the top of the bin pump 12 can be communicated through the feeding pipeline 16, the top of the material bin 11 and the top of the bin pump 12 are communicated through the exhaust pipeline 17, the feeding pipeline 16 and the exhaust pipeline 17 are respectively provided with the feeding valve 14 and the balance valve 15, the feeding valve 14 is used for controlling the feeding of the material bin 11 to the bin pump 12, and the balance valve 15 is used for controlling the exhaust of the internal exhaust gas during the feeding process of the bin pump 12, so as to ensure the safety and stability of the feeding process; the discharging valve 32 can be arranged between the mixing chamber 13 and the snifter 56 on the conveying pipeline 31, so as to control the discharging of the fluidization chamber; and other types of valves can be arranged on the primary air inlet pipeline 41 and the snifting air inlet pipeline 51, so as to control the cut-off of the air path and prevent the backflow of the gas.

[0068] In the embodiments provided in the present application, the primary air inlet pipeline 41 is also provided with the primary air pneumatic cut-off valve 42, the primary air manual ball valve 44 and the primary air check valve 45, and the snifting air inlet pipeline 51 is also provided with the snifting air pneumatic cut-off valve 52, the snifting air manual ball valve 54 and the snifting air check valve 55. During the material conveying process, the primary air pneumatic cut-off valve 42 and the snifting air pneumatic cut-off valve 52 are in the fully open state, and automatically and quickly in the fully closed state after the material conveying is completed and the gas source is cut off, so as to automatically open and close the air path according to the working state of the system, and the structure is simple, the reaction is sensitive, and the action is reliable; the primary air manual ball valve 44 and the snifting air manual ball valve 54 are manually placed in the fully open state when the material conveying starts, and can be manually cut off when the system needs to be maintained, so as to be convenient to operate and quickly open and close; the primary air check valve 45 and the snifting air check valve 55 are all one-way valves, which can avoid the backflow of the material in the bin pump 12 and the conveying pipeline 31 into the gas source 2.

[0069] In the pneumatic conveying process, the gas flow not only affects the conveying pressure, but also affects the system output. The pneumatic conveying system provided in the application can adjust the air inlet according to the conveying pressure, the system output, or both the conveying pressure and the system output, and the application does not limit this. To calculate the system output, in the embodiments provided in the application, the pneumatic conveying system further comprises a material weighing device 7 and / or a solid flow measuring instrument 8; the material weighing device 7 is used to weigh the mass of the material conveyed from the fluidization chamber to the conveying pipeline 31, and the material conveying mass measured by the material weighing device 7 can be used to calculate the system output of the pneumatic conveying system; the solid flow measuring instrument 8 is used to measure the material conveying flow of the conveying pipeline 31, and the material conveying flow measured by the solid flow measuring instrument 8 can be used to calculate the system output of the pneumatic conveying system; the air inlet flow of the primary air inlet pipeline 41 and the assist blowing air inlet pipeline 51 can be adjusted according to the calculated system output.

[0070] When specifically arranged, the structure of the material weighing device 7 is not limited, which can be a weighing sensor arranged in the bin pump 12 to measure the weight of the material in the bin pump 12 through sensing; or the bin pump 12 can be arranged on a support frame, and the material weighing device 7 can be arranged below the support frame; the weight of the material conveyed from the bin pump 12 to the conveying pipeline 31 can be obtained by weighing the weight change of the bin pump 12 within a period of time.

[0071] It can be understood that the solid flow measuring instrument 8 can be arranged downstream of the assist blower 56 on the conveying pipeline 31, so that the material flow measured by the solid flow measuring instrument 8 is the material flow after assist blowing on the conveying pipeline 31, which can better reflect the actual output of the system.

[0072] The application further provides a pneumatic conveying method, which utilizes the above-mentioned pneumatic conveying system to convey material and adjusts the air inlet flow of the primary air inlet pipeline 41 and the assist blowing air inlet pipeline 51 according to the conveying pressure and the system output, and specifically comprises the following steps:

[0073] Data acquisition step: acquiring the conveying pressure and the system output of the pneumatic conveying system;

[0074] Air inlet flow adjustment step: adjusting the air inlet flow of the primary air inlet pipeline 41 and the assist blowing air inlet pipeline 51 according to the acquired conveying pressure and system output, so that the conveying pressure of the pneumatic conveying system reaches the preset conveying pressure range and the system output reaches the preset system output range.

[0075] Please continue to refer to Figure 2 , Figure 2 The flow chart of the air inlet adjustment in the pneumatic conveying method of the embodiments provided in the application.

[0076] In the embodiments provided in this application, a primary gas regulating valve 43 and an auxiliary blowing gas regulating valve 53 are respectively provided on the primary gas inlet pipe 41 and the auxiliary blowing gas inlet pipe 51;

[0077] The data acquisition steps also include: acquiring the total air volume Q of the pneumatic conveying system, the opening degree K of the blowing air regulating valve 53, and the design output B. s Preset upper limit value of conveying pressure P g Preset minimum value of total gas delivery volume Q min Preset upper limit of total gas delivery volume Q max The opening adjustment range R1 of the primary gas regulating valve 43 and the opening adjustment range R2 of the auxiliary blowing gas regulating valve 53; wherein, the conveying pressure is the highest conveying pressure P of the pneumatic conveying system in the previous period, the total conveying gas volume Q = Q1 + Q2, Q1 is the preset air intake volume of the primary gas regulating valve 43 in the previous period, Q2 is the preset air intake volume of the auxiliary blowing gas regulating valve 53 in the previous period, and the opening adjustment ranges R1 and R2 can be percentages of the opening adjustment;

[0078] The specific steps for adjusting the intake airflow include:

[0079] Compare the system output B in the previous period with the design output B. s Maximum conveying pressure P and upper limit value of conveying pressure P g ,

[0080] When B≥B s And P≤P g When the actual system output is greater than or equal to the design output, and the actual conveying pressure is less than or equal to the upper limit of the conveying pressure, there is no risk of pipe blockage. Determine if K equals 0. If K ≠ 0, reduce the opening of the primary gas regulating valve 43 by R1 and the opening of the auxiliary blowing gas regulating valve 53 by R2 to reduce the total conveying air volume, decrease the conveying speed of the material in the conveying pipeline 31, and appropriately reduce the system output, thereby reducing system energy consumption and pipeline wear. If K = 0, continue comparing Q with Q... min If Q≤Q min Then keep the opening of the primary gas regulating valve 43 unchanged. If Q > Q min The opening of the primary gas regulating valve 43 is reduced by an amplitude of R1 to decrease the total gas volume delivered, reduce system output, and thus reduce system energy consumption and pipeline wear; and / or,

[0081] When B > B s And P > P gWhen the actual system output exceeds the design output and the actual conveying pressure exceeds the upper limit of the conveying pressure, the conveying concentration is too high, posing a risk of pipe blockage. Therefore, the opening of the primary gas regulating valve 43 is reduced by an increment of R1, and the opening of the auxiliary blowing gas regulating valve 53 is increased by an increment of R2. This reduces the primary gas intake to lower the system output and increases the auxiliary blowing gas intake to ensure more thorough and uniform mixing of the material and gas within the conveying pipe 31, thus preventing pipe blockage; and / or,

[0082] When B < B s And P < P g When the actual system output cannot meet the design output and the actual conveying pressure is lower than the upper limit of the conveying pressure, the conveying concentration will not be too high, and there is no risk of pipe blockage. Determine if K equals 0. If K ≠ 0, increase the opening of the primary gas regulating valve 43 by R1 and decrease the opening of the auxiliary blowing gas regulating valve 53 by R2. This increases the primary gas intake to efficiently improve the system output. If K = 0, continue comparing Q with Q... max If Q max Then, the opening of the primary air regulating valve 43 is increased by an amount of R1, thereby increasing the primary air intake to efficiently improve the system output. If Q ≥ Q max The system then enters a fault self-test and outputs a fault alarm; and / or,

[0083] When B < B s And P > P g At this time, the actual system output cannot meet the design output, and the actual conveying pressure is higher than the upper limit of the conveying pressure. The conveying concentration is too high, which poses a risk of pipe blockage. The conveyed material may be relatively coarse, and the total gas volume is insufficient. Compare Q and Q'. max If Q max Then, the opening of the primary air regulating valve 43 is increased by R1, and the opening of the auxiliary blowing air regulating valve 53 is increased by R2. This simultaneously increases both the primary air intake and the auxiliary blowing air intake, thereby increasing the total air volume delivered, improving system output, and preventing pipe blockage. If Q ≥ Q max The system will then enter a fault self-check and output a fault alarm. The system will restart after the fault alarm is cleared.

[0084] The pneumatic conveying method provided in this application adjusts the primary air intake and the auxiliary air intake based on the system output, maximum conveying pressure, total conveying air volume, and the opening of the auxiliary air regulating valve 53. This allows for the reduction of system output and total conveying air volume when the system output exceeds the design output and there is no risk of pipe blockage; reduction of system output and avoidance of pipe blockage when the system output exceeds the design output and there is a risk of pipe blockage; and increase of system output when the system output cannot meet the design output and there is no risk of pipe blockage. In short, it can avoid pipe blockage and reduce system energy consumption and pipe wear. ​​

[0085] It can be understood that the air intake amount in the above four different cases of system output B and maximum conveying pressure P can be adjusted by the corresponding adjustment mode of each case, or only in one or two or three cases, and other cases use other adjustment modes, which is not limited in the application.

[0086] In actual use, the last period can be the last conveying cycle. After a conveying cycle of the pneumatic conveying system is completed, the opening degrees of the primary air regulating valve 43 and the assist air regulating valve 53 are adjusted according to the system output B, the maximum conveying pressure P, the total air quantity Q, and the opening degree K of the assist air regulating valve 53 of the last conveying cycle, and then the next conveying cycle is entered. In this way, the primary air and assist air intake amount of the pneumatic conveying system is adjusted according to the material property change of the last conveying cycle, so that the air intake amount of the next conveying cycle adapts to the material property change, the pipe is not easy to be blocked, and the system energy consumption and pipe wear are reduced.

[0087] The system output B in the pneumatic conveying method provided by the embodiments of the application can be calculated by any one of the following three ways or the average of the calculation results of two or more ways, which is not limited in the application.

[0088] When the fluidization chamber is the bin pump 12 or the mixing chamber 13 connected below the bin pump 12, the conveying time T of the last period is collected, and the system output B is calculated by combining the volume V of the bin pump 12, the material bulk density p, and the material filling rate ψ, that is, B=(V* p* ψ) / T.

[0089] The material conveying quality M and the conveying time T of the last period are collected, and the system output B is calculated as B=M / T.

[0090] The material conveying flow rate q of the conveying pipeline 31 in the last period is collected, and the system output B is calculated as B=q.

[0091] Please continue to refer to Figure 3 , Figure 3 The flow chart of the system output calculation in the pneumatic conveying method provided by the embodiments of the application.

[0092] In the embodiments provided by the application, Figure 3As shown, according to whether the pneumatic conveying system is equipped with a solid flow measuring instrument 8, a material weighing device 7, a corresponding system output calculation method is selected: first, it is judged whether the pneumatic conveying system is equipped with a solid flow measuring instrument 8, if equipped with a solid flow measuring instrument 8, the material conveying flow rate q measured by the solid flow measuring instrument 8 is collected, and the system output B=q is calculated; if not equipped with a solid flow measuring instrument 8, it is judged whether the pneumatic conveying system is equipped with a material weighing device 7, if equipped with a material weighing device 7, the conveying time T and the material conveying mass M measured by the material weighing device 7 are collected, and the system output B=M / T is calculated; if not equipped with a material weighing device 7, the conveying time T, the volume V of the bin pump 12, the material bulk density p, and the material filling rate ψ are collected, and the system output B=(V* p* ψ) / T is calculated.

[0093] In actual use, a controller can be arranged in the pneumatic conveying system provided by the above-mentioned embodiments of the present application, the output ends of the pressure detection device 6, the material weighing device 7, and the solid flow measuring instrument 8 are electrically connected to the input end of the controller, and the output end of the controller is electrically connected to the input ends of the primary air regulating valve 43 and the auxiliary blowing air regulating valve 53, the conveying pressure, conveying mass, and conveying flow rate data measured by the pressure detection device 6, the material weighing device 7, and the solid flow measuring instrument 8 are transmitted to the controller, the controller selects a suitable calculation method to calculate the system output according to the received data, and adjusts the opening of the primary air regulating valve 43 and the auxiliary blowing air regulating valve 53 according to the conveying pressure and the system output to realize efficient regulation of the air intake amount and improve the pneumatic conveying efficiency.

[0094] In the embodiments provided in this application, the pneumatic conveying system and method of this application are applied to the conveying of fly ash collected in various electric fields of an electrostatic precipitator in a thermal power plant. The ash hopper of one electric field of the electrostatic precipitator is a silo 1, which collects a large amount of ash, generally accounting for about 80% of the total ash collected in all electric fields of the electrostatic precipitator. Therefore, the design requirements for the pneumatic conveying system corresponding to the first electric field are relatively high. In addition, a certain margin must be reserved according to the design specifications. Therefore, the pipe diameter configuration of the conveying pipeline of the final pneumatic conveying system is designed based on the ash amount of the first electric field plus the margin. The final velocity of the conveying pipeline is generally below 10 m / s. When the high voltage of the electrostatic precipitator's primary electric field fails to operate normally due to short circuits between the anode and cathode, breakage of the damping resistor, or system malfunctions, the fly ash collected in the ash hopper of the primary electric field consists entirely of relatively coarse and heavy fly ash that settles by its own weight. While the amount of this settled ash is less than when the high voltage is operating normally (accounting for approximately 10%-15% of the total ash), its coarseness and weight make it difficult to transport, requiring a final velocity of 18-20 m / s. To avoid pipe blockage caused by the settled ash, traditional pneumatic conveying systems often transport the settled ash by significantly increasing the total air volume, changing the diameter of the conveying pipe 31, or adding supplementary air devices along the conveying pipe 31. However, significantly increasing the total air volume not only accelerates the wear of the conveying pipe 31 but also severely impacts the air source pressure of the entire system, leading to unstable air source pressure. Changing the pipe diameter or adding supplementary air devices along the pipe are both cumbersome, inconvenient to operate, and costly.

[0095] When using the pneumatic conveying system and method provided in this application embodiment for conveying fly ash from an electrostatic precipitator, the primary air inlet pipe 41 and the auxiliary air inlet pipe 51 upstream and downstream of the silo pump 12 enable the primary air to fluidize the material in the silo pump 12 and the auxiliary air to further mix and convey the material entering the conveying pipe 31. The primary air regulating valve 43 and the auxiliary air regulating valve 53 on the primary air inlet pipe 41 and the auxiliary air inlet pipe 51 enable the opening of the primary air regulating valve 43 and the auxiliary air regulating valve 53 in the next conveying cycle to be adjusted according to the system output B, the maximum conveying pressure P, the total conveying air volume Q, and the opening degree K of the auxiliary air regulating valve in the previous conveying cycle. This allows for the coordinated adjustment of the air intake volume of the two inlets, thereby coordinating the air intake flow rate of the silo pump 12 and the air intake flow rate of the conveying pipe 31. This achieves stable conveying of settled ash and avoids emergency ash unloading from the dust collector ash hopper.

[0096] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the apparatus and core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A pneumatic conveying method, characterized in that, The pneumatic conveying method uses a pneumatic conveying system for material conveying. The pneumatic conveying system includes a fluidizing chamber, a conveying pipe (31), a primary air inlet pipe (41), and an auxiliary blowing air inlet pipe (51). The inlet end of the conveying pipe (31) is connected to the outlet of the fluidizing chamber; the outlet of the primary air inlet pipe (41) is connected to the fluidizing chamber; and the outlet of the auxiliary blowing air inlet pipe (51) is connected to the conveying pipe (31). The pneumatic conveying method includes the following steps: Data acquisition steps: Obtain the conveying pressure and system output of the pneumatic conveying system; Air intake flow rate adjustment steps: Adjust the air intake flow rate of the primary air intake pipe (41) and the blowing air intake pipe (51) according to the obtained conveying pressure and system output, so that the conveying pressure of the pneumatic conveying system reaches the preset conveying pressure range and the system output reaches the preset system output range. The primary air intake pipe (41) and the blowing air intake pipe (51) are respectively equipped with a primary air regulating valve (43) and a blowing air regulating valve (53); The data acquisition step further includes: acquiring the total air volume Q of the pneumatic conveying system, the opening degree K of the blowing air regulating valve (53), and the design output B. s Preset upper limit value of conveying pressure P g Preset minimum value of total gas delivery volume Q min Preset upper limit of total gas delivery volume Q max The opening adjustment range R1 of the primary gas regulating valve (43) and the opening adjustment range R2 of the auxiliary blowing gas regulating valve (53); wherein, the conveying pressure is the highest conveying pressure P of the pneumatic conveying system in the previous period; The intake airflow adjustment steps specifically include: Compare the system output B in the previous period with the design output B. s Maximum conveying pressure P and upper limit value of conveying pressure P g , When B≥B s And P≤P g When K is equal to 0, determine whether K is equal to 0. If K ≠ 0, reduce the opening of the primary gas regulating valve (43) by R1 and reduce the opening of the auxiliary blowing gas regulating valve (53) by R2. If K = 0, continue to compare Q with Q. min If Q≤Q min Then keep the opening of the primary gas regulating valve (43) unchanged. If Q>Q min Then reduce the opening of the primary gas regulating valve (43) by an amount of R1; and / or, When B > B s And P > P g At the same time, the opening of the primary gas regulating valve (43) is reduced by an amount of R1, and the opening of the auxiliary blowing gas regulating valve (53) is increased by an amount of R2; and / or, When B < B s And P < P g When K is equal to 0, determine whether K is equal to 0. If K ≠ 0, increase the opening of the primary gas regulating valve (43) by R1 and decrease the opening of the auxiliary blowing gas regulating valve (53) by R2. If K = 0, continue to compare Q with Q max If Q max Then increase the opening of the primary gas regulating valve (43) by an amplitude of R1. If Q ≥ Q max The system then enters a fault self-test and outputs a fault alarm; and / or,​ When B < B s And P > P g When comparing Q with Q max If Q max Then increase the opening of the primary gas regulating valve (43) by an increment of R1 and increase the opening of the auxiliary blowing gas regulating valve (53) by an increment of R2. If Q ≥ Q max The system will then enter a fault self-check and output a fault alarm.​ 2. The pneumatic conveying method according to claim 1, characterized in that, The system output is calculated using any one of the following three methods, or by averaging the results of any two or more methods: When the fluidization chamber is a silo pump (12) or a mixing chamber (13) connected below the silo pump (12), the conveying time T of the previous period is collected, and the system output B = (V*ρ*ψ) / T is calculated by combining the volume V, material bulk density ρ, and material filling rate ψ of the silo pump (12). Collect the material conveying mass M and conveying time T from the previous time period, and calculate the system output B=M / T; Collect the material conveying flow rate q of the conveying pipeline (31) mentioned in the previous time period, and calculate the system output B=q.

3. The pneumatic conveying method according to claim 1 or 2, characterized in that, The pneumatic conveying system also includes: a pressure detection device (6); The pressure detection device (6) is installed in the fluidization chamber or the conveying pipe (31). The pressure detection device (6) is used to detect the conveying pressure of the fluidization chamber or the conveying pipe (31) and adjust the air flow rate of the primary gas inlet pipe (41) and the blowing gas inlet pipe (51) according to the conveying pressure detected by the pressure detection device (6).

4. The pneumatic conveying method according to claim 1 or 2, characterized in that, The pneumatic conveying system also includes: a blower (56); The blowing aid (56) is installed on the conveying pipe (31), and the outlet of the blowing aid air inlet pipe (51) is connected to the blowing aid (56).

5. The pneumatic conveying method according to claim 1 or 2, characterized in that, Also includes: Gas source (2); The primary air intake pipe (41) and the blowing air intake pipe (51) are both connected to the air source (2).

6. The pneumatic conveying method according to claim 1 or 2, characterized in that, The pneumatic conveying system also includes: a hopper (11); The fluidization chamber is either a silo pump (12) or a mixing chamber (13) connected below the silo pump (12), and the outlet of the silo (11) is connected to the inlet of the silo pump (12).

7. The pneumatic conveying method according to claim 1 or 2, characterized in that, The pneumatic conveying system also includes: a material weighing device (7) and / or a solid flow meter (8). The material weighing device (7) is used to weigh the mass of material conveyed from the fluidization chamber to the conveying pipe (31). The mass of material conveyed by the material weighing device (7) can be used to calculate the system output of the pneumatic conveying system. The solid flow meter (8) is used to measure the material conveying flow of the conveying pipeline (31), and the material conveying flow measured by the solid flow meter (8) can be used to calculate the system output of the pneumatic conveying system. Adjust the intake flow rate of the primary air intake pipe (41) and the blowing air intake pipe (51) according to the calculated system output.

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