WO2019200710A1

WO2019200710A1 - System and method for clearing blocked pneumatic transport pipe

Info

Publication number: WO2019200710A1
Application number: PCT/CN2018/093016
Authority: WO
Inventors: 杨道龙; 邢邦圣; 王雁翔; 李建平; 刘玉; 黄盼盼; 胡艳
Original assignee: 江苏师范大学
Priority date: 2018-04-16
Filing date: 2018-06-27
Publication date: 2019-10-24
Also published as: AU2018417114B2; CN108584443A; AU2018417114A1

Abstract

A system for clearing a blocked pneumatic transport pipe. A material transport pipe (11) is provided with a pressure measurement system and a counter pressure increasing system sequentially arranged in a material flow direction. The pressure measurement system comprises a pressure measurement pipe (6) and a pressure sensor (6-1). The counter pressure increasing system comprises a counter pressure increasing pipe (9), an electrically-controlled directional control valve (8), a transport flow valve (7), a reverse flow valve (10), a high-pressure air transport pipe (1), and a vacuum suction pipe (3). Three pipe connectors (9-1) and three ring-shaped air cavities (9-2) are arranged at the counter pressure increasing pipe (9). The three ring-shaped air cavities (9-2) are respectively provided with a set of rotational-flow holes (9-3), a set of pressure increasing holes (9-4) and a set of counter-rotational-flow holes (9-5) running towards the inside of the counter pressure increasing pipe (9). The system can increase pressure and prevent blocking of a pipe.

Description

Pneumatic conveying pipeline blocking and unblocking system and method

Technical field

The invention relates to a pneumatic conveying pipeline blocking and unblocking system and method, and is suitable for an air pneumatic conveying system of a dilute phase and a dense phase inert material.

Background technique

A pneumatic conveying system is a conveying system that transports granular materials in a pipeline by using a gas stream having a certain pressure and a certain speed. The pneumatic conveying pipeline is generally a mixed medium of air and powder materials, and belongs to the category of gas-solid two-phase flow. During the pneumatic conveying process, due to the friction between the material and the pipe and the friction between the materials, the conveying speed of the material is gradually reduced, and finally the material is blocked at a position where the pressure loss is large such as a bent pipe or a bifurcated pipe.

Therefore, in known pneumatic conveying systems, in order to alleviate the occurrence of clogging, a supercharging device is often added to the pneumatic conveying system. However, when the material is agglomerated, there will be a blockage of the pipe. At this time, the positive pressurization may cause the plug of the blocked pipe to become tighter. Once the plug is stuck in the pipe, the subsequent material continues to accumulate. Increased pipeline blockage, resulting in complete blockage of the pipeline, causing accidents such as a pneumatic conveying system. Therefore, timely elimination of the plug that causes the blockage is the key to ensure the smooth and efficient delivery of the pneumatic conveying system.

Summary of the invention

In order to overcome the above-mentioned deficiencies of the prior art, the present invention provides a pneumatic conveying pipeline blocking and unblocking system and method, which can generate a rapid reverse impact flow field while timely satisfying the normal conveying supercharging effect, and timely disperse the blocked material plug. It can meet the demand of partial or overall pressurized conveying of pipelines, and prevent pipeline clogging accidents.

The technical solution adopted by the present invention to solve the technical problems thereof is:

A pneumatic conveying pipeline blocking and unblocking system comprises a material conveying pipeline, and a pressure measuring system and a reverse pressure increasing system are arranged along the material flow direction on the material conveying pipeline, and the pressure measuring system comprises a pressure measuring system including a pressure measuring tube, The dustproof can and the pressure sensor are connected to the material conveying pipe at the left and right ends of the pressure measuring tube, and the pressure measuring hole is opened at the upper end of the pressure measuring tube, the dustproof can is installed on the pressure measuring hole, and the pressure measuring hole is installed between the pressure measuring hole and the dustproof can. The filter net, the pressure sensor is installed on the upper part of the dustproof tank, the filter net and the dustproof tank can prevent the conveying material particles from blocking the pressure measuring hole and prevent the material dust from entering the pressure sensor, affecting the measurement result; the reverse pressure increasing system includes the reverse supercharging tube , electronically controlled reversing valve, conveying flow valve, reverse flow valve, high pressure air conveying pipe and vacuum exhaust pipe, three pipe joints and three annular air chambers on the reverse boosting pipe, three pipe connections One end of the head is respectively connected with the annular air chambers in the three reverse pressure tubes, and the other end is respectively connected with the air flow conveying pipeline, and the three annular air chambers respectively open a set of swirl holes to the inside of the reverse pressure increasing tube. A set of pressurized holes and a set of reverse swirling holes, the swirling holes located behind the conveying direction of the pipe are at an angle to the axial and radial directions of the pipe, and the working direction is the same as the direction of material conveying, and is located in the middle of the conveying direction of the flow. The pressing hole is perpendicular to the axial direction of the pipe and the working direction is perpendicular to the material conveying direction. The reverse swirling hole in front of the conveying direction of the pipe is at an angle with the axial direction and the radial direction of the pipe, and the working direction is opposite to the direction of material conveying; the swirling hole is The interface is connected to the outlet of the electronically controlled directional control valve, the inlet I of the electrically controlled directional control valve is connected to the outlet of the delivery flow valve, the inlet II of the electrically controlled directional control valve is connected to the vacuum suction pipe, the inlet of the delivery flow valve and the high pressure air delivery The tubes are connected, the interface of the booster hole and the reverse swirling hole are connected to the outlet of the reverse flow valve, and the inlet of the reverse flow valve is connected with the high-pressure air conveying pipe; the data collecting instrument and the data analysis controller are also included, and the pressure is included. The data output end of the sensor is connected to the data acquisition device through a data transmission line, and the control end of the electronically controlled reversing valve is connected to the data analysis controller through a data transmission line, and the flow rate valve is Flow valve to the control terminal are connected by data transmission lines and the data analysis controller, data logger and the data analyzed using the data transmission between the controller cable.

A pneumatic conveying pipeline plugging and unblocking method comprises the following steps:

1) In the material conveying pipeline, arrange a plurality of sets of pressure measuring systems and reverse pressure increasing systems along the flow direction of the materials;

2) The pressure measuring system transmits the change of the flow field pressure in the material conveying pipeline obtained in real time to the data collecting instrument;

3) The data acquisition device transmits the collected pressure data to the data analysis controller;

4) The data analysis controller analyzes the change of the flow field pressure and compares it with the preset normal delivery value of the pneumatic conveying;

5) During the normal conveying process, the conveying flow valve and the reverse pressure increasing valve in the entire pneumatic conveying system are in the closed state, and the electrically controlled reversing valve is in the I position, that is, the swirling flow of the conveying flow valve and the reverse supercharging tube Hole is turned on;

6) During the normal conveying process, when the N-position of the material conveying pipe and the pressure field obtained by the pressure measuring system at N+1 are lower than the normal conveying value, and the entire conveying system does not have a sudden high flow field pressure, the data The analysis controller opens the delivery flow valve at the nearest upstream N-1 from the distance N, so that the high-pressure airflow in the high-pressure air delivery pipe enters the swirling hole of the reverse boosting pipe at the upstream N-1, generating a swirling pressurized conveying effect;

7) During the normal conveying process, when the pressure of the flow field obtained by the pressure measuring device at the N position of the material conveying pipe suddenly rises, and the downstream N+1 position and the subsequent flow field pressure are lower than the normal conveying value, it indicates that the N position is At the downstream N+1 position, the current pipeline blockage accident occurs. The data analysis controller closes the N5 and N+2 delivery flow valves, and opens the N and N+1 reverse flow valves to make the high pressure air delivery. The high-pressure gas flow in the tube enters the pressure-increasing hole and the reverse swirling hole of the N and N+1 reverse-pressurizing tubes, and the reverse swirling hole generates a reverse swirling impact to block the pile, and the boosting hole is both opposite Providing sufficient back pressure and high pressure air to the swirling flow, and preventing the material in the downstream conveying pipe from being sucked into the reverse swirling flow;

8) At the same time that the reverse swirling is opened, the electronically controlled directional control valve upstream of the N position is switched to the II position, that is, the swirling holes of the vacuum suction pipe and the reverse pressure increasing pipe are turned on, and a vacuum negative pressure is generated to increase the blockage material. The differential pressure before and after the stack increases the reverse thrust while discharging the excess reverse airflow to prevent problems in subsequent transportation. This process is called a reverse impact process;

9) The reverse impact process time is short, between 10ms and 1000ms, after a reverse impact is completed, the material conveying pipeline resumes the conveying state. If the flow field pressure in step 7) continues to rise, continue to step 7 And step 8) until normal delivery is resumed.

Compared with the prior art, the pneumatic conveying pipeline blocking and unblocking system and method of the present invention arranges a plurality of sets of pressure measuring systems and reverse supercharging systems along the flow direction of materials in the material conveying pipeline. The pressure field pressure obtained by the pressure measuring system is sent to the data acquisition instrument and the data analysis controller, and compared with the preset normal delivery value, when the flow field pressure at a certain position and after is lower than the normal delivery value, And when there is no sudden high flow field pressure in the whole system, the nearest upstream delivery flow valve is opened, so that the high pressure airflow enters the swirling hole of the reverse boosting tube to generate the swirling pressurized conveying effect; when a certain position When the flow field pressure suddenly rises and the downstream flow field pressure is lower than the normal delivery value, the two reverse flow valves that are closest to the downstream distance are opened, and a reverse impact force is generated to flush the blockage pile and simultaneously close the position. The upstream vacuum suction pipe and the reverse pressure tube have a vacuum negative pressure to increase the differential pressure before and after the blockage, increase the reverse thrust, and discharge the excess reverse flow to prevent subsequent delivery. Problem. The invention can generate a rapid reverse impact flow field while absorbing the normal conveying supercharging effect, and rushing and blocking the plug, so as to meet the requirement of partial or overall supercharging of the pipeline, and prevent the occurrence of pipeline clogging accidents, Strong innovation and wide practicality.

DRAWINGS

The invention will now be further described with reference to the drawings and embodiments.

FIG. 1 is a schematic structural view of a plugging and unblocking system according to an embodiment of the present invention.

2 is a schematic structural view of the reverse booster tube of FIG. 1.

3 is a schematic structural view of the pressure measuring system of FIG. 1.

In the figure: 1, high-pressure air delivery pipe, 2, data acquisition instrument, 3, vacuum extraction pipe, 4, data analysis controller, 5, connection tee, 6, pressure measuring tube, 6-1, pressure sensor, 6- 2, dust can, 6-3, filter, 6-4, pressure measuring hole, 7, delivery flow valve, 8, electronically controlled reversing valve, 9, reverse booster tube, 10, reverse flow valve, 11. Material conveying pipe, 9-1, pipe joint, 9-2, annular gas chamber, 9-3, swirl hole, 9-4, booster hole, 9-5, reverse swirl hole.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. It is a part of the embodiment of the invention, not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

1 to 3 are schematic views showing the structure of a preferred embodiment of the present invention. A pneumatic conveying pipe blocking and unblocking system of Fig. 1 includes a material conveying pipe 11 along which a material flows along the material conveying pipe 11 A pressure measuring system and a reverse pressure boosting system are installed, and the pressure measuring system includes a pressure measuring tube 6, a dustproof tank 6-2 and a pressure sensor 6-1, and the connecting flange and the material are connected at the left and right ends of the pressure measuring tube 6. The conveying pipe 11 is connected, and the upper end of the pressure measuring pipe 6 is provided with a pressure measuring hole 6-4, and the dustproof tank 6-2 is installed on the pressure measuring hole 6-4, and the pressure measuring hole 6-4 and the dustproof can 6-2 The filter 6-3 is installed between the dustproof tank 6-2, and the pressure sensor 6-1 is installed on the upper part of the dustproof tank 6-2. The filter net 6-3 and the dustproof tank 6-2 can prevent the conveying material particles from blocking the pressure measuring hole and preventing the material dust from entering the pressure. Sensor 6-1, affecting the measurement results (as shown in Figure 3); reverse pressure boosting system includes reverse booster tube 9, electronically controlled directional control valve 8, delivery flow valve 7, reverse flow valve 10, high pressure air delivery Tube 1 and vacuum suction pipe 3, see Fig. 2, three pipe joints 9-1 and three annular gas chambers 9-2 are provided on the reverse pressure pipe 9, one of the three pipe joints 9-1 The ends are respectively connected with the annular plenum 9-2 in the three reverse boosting tubes 9, and the other ends are respectively connected to the pipelines for the airflow transport, and the three annular plenums 9-2 are respectively directed to the reverse boosting tubes 9 The inside is provided with a set of swirl holes 9-3, a set of pressurizing holes 9-4 and a set of counter swirl holes 9-5, and the swirl holes 9-3 located behind the flow conveying direction are axially and radially of the pipe. The angle is the same and the working direction is the same as the material conveying direction. The pressure increasing hole 9-4 located in the middle of the conveying direction is perpendicular to the axial direction of the pipe and the working direction is perpendicular to the material conveying direction, and the reverse swirling hole 9 is located in front of the conveying direction. -5 is at an angle to the axial and radial directions of the pipe and the working direction is opposite to the direction of material transport; the interface of the swirl hole 9-3 is connected to the outlet of the electrically controlled directional control valve 8, and the inlet I of the electrically controlled directional control valve 8 Connected to the outlet of the delivery flow valve 7, the inlet II of the electrically controlled directional control valve 8 is connected to the vacuum suction pipe 3, the inlet of the delivery flow valve 7 is connected to the high pressure air delivery pipe 1, the plenum 9-4 and the reverse swirl The interface of the hole 9-5 is connected to the outlet of the reverse flow valve 10, and the inlet of the reverse flow valve 10 is connected to the high pressure air delivery pipe 1; The data acquisition device 2 and the data analysis controller 4, the data output end of the pressure sensor 6-1 is connected to the data acquisition device 2 through a data transmission line, and the control end of the electronically controlled reversing valve 8 is connected to the data analysis controller 4 through a data transmission line. The control ends of the delivery flow valve 7 and the reverse flow valve 10 are connected to the data analysis controller 4 through a data transmission line, and the data acquisition device 2 and the data analysis controller 4 are connected by a data transmission line.

In this embodiment, the material conveying pipe 11 is preferably provided with a plurality of sets of pressure measuring systems and a reverse pressure increasing system, which are better in use; specifically, the pressure measuring system and the reverse pressure increasing system respectively The two ports of the pressure measuring tube 6 and the reverse pressure tube 9 are connected to the material conveying pipe 11, and specifically, the pressure measuring tube 6 and the reverse pressure tube 9 may be connected to the material conveying pipe 11 through the connecting flange. .

Preferably, each of the sets of swirl holes 9-3, each set of pressurizing holes 9-4 and each set of counter swirl holes 9-5 are evenly spaced on the respective annular air chambers 9-2, The number of holes per group of swirl holes 9-3, each group of pressurizing holes 9-4, and each group of counter swirl holes 9-5 is 4 to 10.

As a specific implementation manner, the electronically controlled reversing valve 8 and the vacuum exhausting pipe 3, the conveying flow valve 7 and the high-pressure air conveying pipe 1, the reverse flow valve 10 and the high-pressure air conveying pipe 1 can all be connected through the tee 5 Connected.

1) in the material conveying pipe 11, a plurality of sets of pressure measuring systems and reverse pressure increasing systems along the flow direction of the materials are arranged;

2) The pressure measuring system transmits the change of the flow field pressure in the material conveying pipe 11 obtained in real time to the data collecting instrument 2;

3) The data acquisition device 2 transmits the collected pressure data to the data analysis controller 4;

4) The data analysis controller 4 analyzes the flow field pressure change and compares it with a preset normal delivery value of the pneumatic power transmission;

5) During the normal conveying process, the conveying flow valve 7 and the reverse pressure increasing valve 9 in the entire pneumatic conveying system are all in the closed state, and the electrically controlled switching valve 8 is in the I position, that is, the conveying flow valve 7 and the reverse supercharging The swirl hole 9-3 of the tube 9 is turned on;

6) During the normal conveying process, when the flow field pressure obtained by the pressure measuring system at the position of the material conveying pipe 11N and after N+1 is lower than the normal conveying value, and the entire conveying system does not have a sudden high flow field pressure, the data The analysis controller 4 opens the delivery flow valve 7 at the nearest upstream N-1 from the distance N, so that the high pressure gas flow in the high pressure air delivery pipe 1 enters the swirling hole 9 of the reverse pressurized pipe 9 at the upstream N-1. 3, generating a swirling pressurized conveying effect;

7) During the normal conveying process, when the pressure of the flow field obtained by the pressure measuring device 6 at the position of the material conveying pipe 11N suddenly rises, and the downstream N+1 position and the subsequent flow field pressure are lower than the normal conveying value, the N position is indicated. The pipeline interception accident occurs at the downstream N+1 position, and the data analysis controller 4 closes the delivery flow valve 7 at two places N+1 and N+2, and opens the reverse flow valve 10 at two places N and N+1. The high-pressure airflow in the high-pressure air delivery pipe 1 is introduced into the pressurizing hole 9-4 and the reverse swirling hole 9-5 of the reverse boosting pipe 9 at two positions N and N+1, and the reverse swirling hole 9-5 is generated. The reverse swirling impact blocks the pile, while the booster bore 9-4 provides sufficient back pressure and high pressure air for the reverse swirl and prevents the material in the downstream duct from being drawn into the reverse swirl;

8) At the same time that the reverse swirl is opened, the electronically controlled directional control valve 8 upstream of the N position is switched to the II position, that is, the swirling holes 9-3 of the vacuum exhaust pipe 3 and the reverse boosting pipe 9 are turned on, generating a vacuum negative Pressing to increase the pressure difference before and after blocking the pile, increasing the reverse thrust, and discharging the excess reverse airflow to prevent problems in subsequent transportation, the process is called reverse impact process;

9) The reverse impact process time is short, between 10ms and 1000ms, after a reverse impact is completed, the material conveying pipe 11 resumes the conveying state, and if the flow field pressure in the step 7) continues to rise, the steps are continued. 7) and step 8) until normal delivery is resumed.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way. Any simple modifications and equivalent changes made to the above embodiments in accordance with the technical spirit of the present invention fall into the present invention. Within the scope of protection of the invention.

Claims

A pneumatic conveying pipeline blocking and unblocking system comprises a material conveying pipeline (11), characterized in that: a pressure measuring system and a reverse pressure increasing system are installed along the material flow direction on the material conveying pipeline (11), and the pressure is measured. The system includes a pressure measuring tube (6), a dustproof tank (6-2) and a pressure sensor (6-1). The left and right ends of the pressure measuring tube (6) are connected to the material conveying pipe (11), and the pressure measuring tube (6) The upper middle end has a pressure measuring hole (6-4), the dustproof tank (6-2) is mounted on the pressure measuring hole (6-4), the pressure measuring hole (6-4) and the dustproof can (6-2) Install a filter (6-3) between them, and install a pressure sensor (6-1) on the top of the dust can (6-2);

The reverse pressure boosting system includes a reverse booster tube (9), an electronically controlled reversing valve (8), a delivery flow valve (7), a reverse flow valve (10), a high pressure air delivery tube (1), and a vacuum evacuation tube. (3) There are three pipe joints (9-1) and three annular gas chambers (9-2) on the reverse booster pipe (9), one end of three pipe joints (9-1) They are respectively connected with the annular air chambers (9-2) in the three reverse boosting tubes (9), and the other ends are respectively connected to the pipelines for airflow transportation, and the three annular air chambers (9-2) are respectively reversed. A swirling hole (9-3), a set of pressurized holes (9-4) and a set of reverse swirling holes (9-5) are opened inside the booster pipe (9), which are located behind the conveying direction. The swirling hole (9-3) is at an angle to the axial and radial directions of the pipe and the working direction is the same as the material conveying direction. The pressurized hole (9-4) located in the middle of the conveying direction is perpendicular to the pipe axis and the working direction. In the vertical material conveying direction, the reverse swirling hole (9-5) located in front of the conveying direction of the pipe is at an angle with the axial direction and the radial direction of the pipe, and the working direction is opposite to the direction of material conveying; the swirling hole (9-3) The interface is connected to the outlet of the electronically controlled reversing valve (8), and the inlet I and the delivery of the electrically controlled reversing valve (8) The outlet of the flow valve (7) is connected, the inlet II of the electrically controlled directional control valve (8) is connected to the vacuum suction pipe (3), and the inlet of the delivery flow valve (7) is connected to the high pressure air delivery pipe (1). (9-4) is connected to the outlet of the reverse flow valve (10) after being connected to the interface of the reverse swirl hole (9-5), and the inlet of the reverse flow valve (10) is connected to the high pressure air delivery pipe (1) ;

It also includes a data acquisition device (2) and a data analysis controller (4). The data output end of the pressure sensor (6-1) is connected to the data acquisition device (2) through a data transmission line, and the control of the electronically controlled reversing valve (8) The end is connected to the data analysis controller (4) through the data transmission line, and the control ends of the delivery flow valve (7) and the reverse flow valve (10) are connected to the data analysis controller (4) through the data transmission line, and the data acquisition instrument (2) ) A data transmission line is connected to the data analysis controller (4).
A pneumatic conveying pipeline blocking and unblocking system according to claim 1, wherein said material conveying conduit (11) is provided with a plurality of sets of spaced apart pressure measuring systems and reverse pressure increasing systems, pressure measuring systems and The reverse pressure boosting system is connected to the material conveying pipe (11) through two ports of the pressure measuring pipe (6) and the reverse pressure pipe (9).
A pneumatic conveying pipe blocking and unblocking system according to claim 1 or 2, characterized in that: each group of swirl holes (9-3), each group of pressurizing holes (9-4) and each group of reverse The swirl holes (9-5) are evenly spaced on the respective annular gas chambers (9-2), each group of swirl holes (9-3), each group of pressurizing holes (9-4) and each The number of holes in the group of reverse swirl holes (9-5) is 4 to 10.
The pneumatic conveying pipeline blocking and unblocking system according to claim 3, characterized in that: the electronically controlled reversing valve (8) and the vacuum exhausting pipe (3), the conveying flow valve (7) and the high-pressure air conveying pipe ( 1) The reverse flow valve (10) and the high pressure air delivery pipe (1) are connected by a connecting tee (5).
A pneumatic conveying pipeline blocking and unblocking method, characterized in that the method comprises the following steps:

1) In the material conveying pipe (11), a plurality of sets of pressure measuring systems and reverse pressure increasing systems along the flow direction of the materials are arranged;

2) The pressure measuring system transmits the flow field pressure change in the material conveying pipe (11) obtained in real time to the data collecting instrument (2);

3) The data acquisition instrument (2) transmits the collected pressure data to the data analysis controller (4);

4) The data analysis controller (4) analyzes the pressure change of the flow field and compares it with the preset normal delivery value of the pneumatic transmission;

5) During the normal conveying process, the conveying flow valve (7) and the reverse pressure increasing valve (9) in the entire pneumatic conveying system are all in the closed state, and the electrically controlled reversing valve (8) is in the I position, that is, the conveying flow valve (7) being connected to the swirl hole (9-3) of the reverse booster tube (9);

6) During the normal conveying process, the flow field pressure obtained by the pressure measuring system at the N position of the material conveying pipe (11) and after N+1 is lower than the normal conveying value, and the entire conveying system does not have a sudden high flow field pressure. When the data analysis controller (4) opens the delivery flow valve (7) at the nearest upstream N-1 from the distance N, the high pressure airflow in the high pressure air delivery pipe (1) enters the upstream N-1 and is reversed. The swirling hole (9-3) of the pressure tube (9) produces a swirling pressurized conveying effect;

7) During the normal conveying process, the flow field pressure obtained by the pressure measuring device (6) at the N position of the material conveying pipe (11) suddenly rises, and the downstream N+1 position and the subsequent flow field pressure are lower than the normal conveying value. At the time, it indicates that the N-position to the downstream N+1 position will cause the pipeline to be blocked, and the data analysis controller (4) closes the delivery flow valve (7) at N+1 and N+2, and opens N and N+1. Two reverse flow valves (10) allow the high pressure airflow in the high pressure air delivery pipe (1) to enter the booster holes (9-4) and the opposite of the N and N+1 reverse booster tubes (9). To the swirl hole (9-5), the reverse swirl hole (9-5) generates a reverse swirling impact blockage pile, while the booster hole (9-4) provides sufficient back pressure for the reverse swirl And high-pressure air, which prevents the material in the downstream conveying pipe from being sucked into the reverse swirling flow;

8) At the same time that the reverse swirl is opened, the electronically controlled directional control valve (8) upstream of the N position is switched to the II position, that is, the swirl hole of the vacuum suction pipe (3) and the reverse pressure boosting pipe (9) is turned on ( 9-3), generating a vacuum negative pressure to increase the differential pressure before and after blocking the pile, increasing the reverse thrust, and discharging the excess reverse air flow to prevent problems in subsequent transportation, which is called a reverse impact process;

9) The reverse impact process time is short, between 10ms and 1000ms, after a reverse impact is completed, the material conveying pipe (11) resumes the conveying state. If the flow field pressure in step 7) continues to rise, continue. Perform steps 7) and 8) until normal delivery is resumed.