A stable powder supply method and device suitable for variable cross-section powder storage section

Abstract

The present invention discloses a stable powder supply method and device suitable for a variable cross-section powder storage section, which belongs to the field of fluidized powder conveying. The structure of the powder supply device of the present invention is basically the same as the existing structure, and the powder storage section has an irregular cross-section; a plurality of slide rails are arranged along the inner wall of the powder supply device; the flexible dense membrane is connected to the guide rail on the circumferential outer side and fixed at the end of the slide rail, that is, fixed at the end of the powder supply device; the powder supply gas enters the powder storage section from the powder supply gas inlet of the powder storage cover, and forms a small pressure difference inside the upstream of the powder storage section, pushing the slider to move; under the action of the pressure difference between the powder supply gas pressure of the powder storage section and the target environmental pressure, the flexible dense membrane moves downstream to push the powder; through the movement of the slider on the guide rail, it is ensured that the flexible dense membrane is always in contact with the powder body, and the slider, the flexible dense membrane and the powder move together. The present invention provides more space selection margin for the design of aircraft using powder engines.

Description

Technical Field

[0001] The present invention belongs to the field of fluidized powder conveying, and relates to a fluidized powder conveying method and device in the field of aerospace, and specifically to a stable powder supply method and device suitable for a variable cross-section powder storage section. Background Art

[0002] Powder engines have been developed significantly due to their advantages such as high specific impulse, easy fuel storage, and adjustable flow. They use metal powders such as aluminum powder as fuel, release heat through powder combustion, and generate thrust using the principle of jet propulsion. The engine powder supply system is a key component of the powder engine. In order to meet the needs of the engine working under different working conditions, the flow of powder fuel must be adjustable, and the flow under constant working conditions must be stable. The concentration of the powder delivered by the supply system should be as uniform as possible.

[0003] With the improvement of aircraft tactical requirements, the overall design of aircraft has also put forward higher requirements on the position and volume of the engine in the aircraft structure. For aircraft using powder engines, their powder supply devices are usually cylindrical with constant cross-section. In the design of the internal space of the aircraft, the single structural form of the powder supply device not only occupies a large volume, but also limits the structural design and development of the internal warhead and guidance system of the aircraft due to its fixed structure.

[0004] The use of a powder supply device with a variable cross-section powder storage section can provide more space selection margin for the interior design of the aircraft. The structure of the powder supply device can be appropriately adjusted according to the structure of the remaining systems, giving the structural design of the remaining systems inside the aircraft more choice space. At this time, the powder supply scheme that can be applied to the constant cross-section cylindrical powder storage section has limitations. The method of pneumatically or electrically driving the piston to add fluidizing gas flow cannot be used due to the variable cross-section structure of the powder storage section. The existing powder supply method is difficult to apply to such scenarios. It is of great significance to develop a stable powder supply method and device suitable for variable cross-section powder storage sections. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects of using a single structural form of powder supply device in the existing powder engine design, which imposes great restrictions on the internal space design of the aircraft. In order to provide more space selection margin for the design of aircraft using powder engines, and to overcome the defects of the existing powder supply method in the application of powder engines using variable cross-section powder storage sections, the present invention provides a stable powder supply method and device suitable for variable cross-section powder storage sections, which can achieve continuous and stable supply of metal powder.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] The present invention discloses a stable powder supply method suitable for a variable cross-section powder storage section, which mainly utilizes the pressure difference between the powder supply gas pressure of the powder storage section and the target environment pressure to drive the flexible dense membrane to move, and ensures that the flexible dense membrane is always in contact with the powder body through the movement of the slider on the guide rail, and the flexible dense membrane drives the powder to move downstream. Under the push of the flexible dense membrane, fluidizing gas is introduced into the fluidizing chamber to fluidize the powder, driving the powder to be transported from the outlet to the target environment where the powder is needed.

[0008] The variable cross-section powder storage section refers to the powder engine, which is limited by the internal space of the aircraft. The metal powder storage section needs to be designed with an irregular cross-section, including a non-constant cross-section columnar structure such as a variable curve powder storage section and a variable diameter powder storage section. For the convenience of explanation, the present invention is described in terms of a variable diameter powder storage section and a variable curve powder storage section.

[0009] The present invention also discloses a stable powder supply device suitable for a variable cross-section powder storage section, which is used to implement the stable powder supply method suitable for a variable cross-section powder storage section. The stable powder supply device includes a powder supply gas inlet, a powder storage cover, a block, a slider, a flexible dense membrane, a guide rail, a fixing screw, a powder storage section, a powder storage section housing, nuts, bolts, a fluidizing chamber, a fluidizing gas inlet, a powder outlet, a powder supply gas outlet, a solenoid valve, a gas pressure sensor, and a mass sensor.

[0010] The powder supply gas is the gas that enters the powder storage section through the powder supply gas inlet of the powder storage section to drive the powder body to move. The powder supply gas source is high-pressure gas. The fluidizing gas is the gas that enters the fluidizing chamber through the fluidizing gas inlet of the fluidizing chamber to fluidize the powder. The powder supply gas source is high-pressure gas.

[0011] The flexible dense membrane is made of a flexible membrane with a certain thickness and high strength, has high pressure resistance, and does not allow gas to pass through. Preferably, the thickness of the flexible dense membrane is not less than 10 mm.

[0012] The flexible dense membrane comprises a fluororubber soft plate, an expanded polytetrafluoroethylene plate, and a high-pressure resistant silicone pad.

[0013] The slider and guide rail are used to limit the position and movement of the flexible dense membrane, and prevent the flexible dense membrane from being opened or shifted in position by the powder supply gas in the powder storage section, so as to fail to achieve the set goal. The flexible dense membrane is connected to the guide rail on the circumferential outer side. The guide rail is designed as a "convex" structure, which can better fit the flexible dense membrane and increase the fit between the flexible dense membrane and the powder storage section shell. The flexible dense membrane is fixed in the circumferential direction and only moves axially along the guide rail. The guide rail is fixed to the powder storage section shell by screws, and the slider can move freely on the guide rail. A stopper is provided at one end of the guide rail to prevent the slider from falling off the guide rail. The powder supply gas enters the powder storage section from the powder supply gas inlet of the powder storage cover, and forms a small pressure difference inside the upstream of the powder storage section, which pushes the slider to move; under the pressure difference between the powder supply gas pressure in the powder storage section and the target environmental pressure, the flexible dense membrane moves downstream to push the powder. Through the movement of the slider on the guide rail, it is ensured that the flexible dense membrane is always in contact with the powder body, and the slider, the flexible dense membrane and the powder move together.

[0014] Preferably, there are four guide rails, which are evenly distributed along the circumference of the powder storage section.

[0015] The fluidizing chamber is a place where the fluidizing gas fluidizes the powder. It is provided with four fluidizing chamber inlets evenly distributed circumferentially. The fluidizing gas blowing direction forms a specific angle with the axis of the powder feeding device. After the high-speed fluidizing gas enters the fluidizing chamber, it drives the powder in the fluidizing chamber to rotate and flow to the powder outlet along with the fluidizing gas.

[0016] Preferably, the powder supply gas pressure of the powder storage section is controlled by the gas flow of the solenoid valve and the powder supply gas inlet, thereby adjusting the advancement speed of the flexible dense membrane and the powder conveying amount. The greater the powder supply gas pressure in the powder storage section, the greater the powder conveying amount.

[0017] Preferably, a mass sensor is installed in the powder supply device, and the mass sensor is connected to the computer via an acquisition card, and the real-time powder delivery amount during the powder supply process can be obtained through calculation.

[0018] Preferably, accurate control of powder delivery amount and sufficient fluidization are achieved by replacing the fluidizing chamber to change the convergence angle of the fluidizing chamber and the powder outlet diameter, changing the structural dimensions of the device, adjusting the powder supply gas pressure, adjusting the fluidizing gas pore size, and the fluidizing gas flow rate.

[0019] The advancement speed of the flexible dense film is proportional to the pressure difference between the powder supply gas pressure and the target environment, that is:

[0020] v∝(P g -P b )

[0021] Where v is the advancing speed of the flexible dense membrane, P g P is the powder supply pressure in the powder storage section, P b is the target ambient pressure.

[0022] The equivalent area of ​​the flexible dense film is the actual contact area between the flexible dense film and the powder after a certain deformation. The equivalent area of ​​the flexible dense film can be expressed as:

[0023] S=αs

[0024] Among them, α is the equivalent coefficient (1<α<1.5), and s is the circumferential cross-sectional area of ​​the powder storage section.

[0025] The mass flow rate of powder delivery can be expressed as:

[0026]

[0027] in, is the powder mass flow rate, S is the equivalent area of ​​the flexible dense membrane, is the powder filling coefficient, ρ is the true density of the powder, and v is the advancing speed of the flexible dense film.

[0028] The present invention also discloses a working method of a stable powder supply device suitable for a variable-section powder storage section, which is as follows: filling aluminum powder into the powder storage section to ensure that the powder is kept as uniform as possible in the circumferential direction, installing a flexible dense membrane and fixing it in a circumferential position with a guide rail to ensure that the flexible membrane is sealed with the inner wall of the powder storage section shell, installing a slider to enable the slider and the flexible dense membrane to move freely on the guide rail; sealingly connecting the powder storage cover with the powder storage section, and using a quick connector and a hose to ensure a sealed connection between the powder supply gas source and the powder supply gas inlet; closing the solenoid valve, filling the powder storage section with powder supply gas, setting the powder supply gas flow rate, and increasing the powder supply gas pressure for the powder storage section; introducing fluidizing gas from the fluidizing gas inlet, and the powder begins to be transported to the target environment, and adjusting the powder supply gas flow rate and the solenoid valve to adjust the powder supply gas pressure, thereby changing the propulsion speed of the flexible dense membrane and adjusting the powder delivery amount.

[0029] Beneficial effects:

[0030] 1. The present invention discloses a stable powder supply method and device suitable for a variable cross-section powder storage section, which overcomes the defect that the existing powder engine uses a single structural powder supply device, which limits the internal space design of the aircraft, and provides more space selection margin for the design of the powder storage section of the powder engine. The use of a variable cross-section powder storage section provides more space selection opportunities for the aircraft warhead and guidance system. The applicable cross-section range is wide, and powder supply devices with different mask shapes can be selected according to different internal structures of the aircraft, and the prospects are promising.

[0031] 2. The present invention discloses a stable powder supply method and device suitable for a variable cross-section powder storage section. Aiming at the special structure of variable cross-section, the method and device are fluidized by fluidizing gas and utilize the pressure difference between the powder supply gas pressure and the back pressure in the powder storage section to drive the movement of metal powder in the powder storage section. The ingenious form of a slider plus a flexible dense membrane is used to achieve the multiple goals of transmitting the pressure difference to assist in pushing the powder, preventing the powder from overflowing, and assisting in forming a high-pressure zone for the powder supply gas. The method and device have a simple structure and are easy to use.

[0032] 3. The present invention discloses a stable powder supply method and device suitable for a variable cross-section powder storage section, which overcomes many disadvantages of the previous mechanical piston powder supply device, such as complex structure (a power device with a piston needs to be installed) and a large risk of mechanical structure failure (the mechanical movement of the piston will cause excessive extrusion of the powder, and the powder tank pressure will rise sharply when the powder is not discharged smoothly, resulting in structural failure). The present invention uses pure pneumatic fluidization to supply powder and uses a dense flexible membrane to replace the role of the mechanical piston. The powder is subjected to less extrusion force and reduced deformation, the structural reliability is high, and stable powder transportation is achieved.

[0033] 4. The present invention discloses a stable powder supply method and device suitable for a variable cross-section powder storage section, which replaces the fluidizing chamber to change the convergence angle of the fluidizing chamber and the powder outlet diameter, changes the device structure size, adjusts the powder supply gas pressure, adjusts the fluidizing gas pore size, and the fluidizing gas flow rate to achieve accurate control of the powder delivery amount and sufficient fluidization, and adopts a mass sensor plus a sensor method to obtain the real-time powder delivery amount.

[0034] 5. The present invention discloses a stable powder supply method and device suitable for a variable cross-section powder storage section, wherein each part is connected by threads, which is convenient for sealing and has high structural reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is the principle diagram of the stable powder supply device in the variable curve powder storage section.

[0036] Figure 2 It is a structural diagram of the stable powder supply device of the variable curve powder storage section in the present invention.

[0037] Figure 3 This is the schematic diagram of the variable diameter powder storage section stable powder supply device.

[0038] Figure 4 It is a structural diagram of the stable powder supply device of the variable diameter powder storage section in the present invention.

[0039] Figure 5 It is the AA section view of the variable diameter and variable curve powder storage section stable powder supply device;

[0040] Among them: 1-powder storage cover, 2-powder supply gas inlet, 3-slider, 4-fluororubber soft plate, 5-powder storage section housing, 6-powder storage section, 7-fixing screws, 8-nuts, 9-bolts, 10-fluidizing chamber, 11-powder outlet, 12-fluidizing gas inlet, 13-fluidizing chamber housing, 14-guide rail, 15-square stopper, 16-powder supply gas outlet, 17-solenoid valve, 18-gas pressure sensor. DETAILED DESCRIPTION

[0041] In order to better illustrate the purpose and advantages of the present invention, the invention is further described below with reference to the accompanying drawings and examples.

[0042] Embodiment 1:

[0043] This embodiment uses 20μm to 30μm aluminum particles as fuel, high-pressure air as powder supply gas and fluidizing gas, and adopts a powder storage section in the form of a variable curve structure to supply powder fuel to the combustion chamber of the test engine. The powder delivery flow rate is required to be basically maintained at 40g / s. In this embodiment, the flexible dense membrane is selected as a fluororubber soft plate. Figure 1 Schematic diagram of the stable powder supply method in the variable curve powder storage section.

[0044] The principle described above mainly utilizes the pressure difference between the powder supply gas pressure and the back pressure in the powder storage section to push the fluororubber soft plate 4 to move. The movement of the slider 3 on the guide rail 14 ensures that the fluororubber soft plate 4 is always in contact with the powder body, and the fluororubber soft plate 4 pushes the powder to move downstream. Under the push of the fluororubber soft plate 4, fluidizing gas is introduced into the fluidizing chamber 10 to fluidize the powder. The fluidizing chamber 10 is provided with 4 fluidizing gas inlets. The direction in which the fluidizing gas enters the fluidizing chamber 10 forms an angle of 45° with the axial direction of the powder supply device. The fluidizing gas drives the powder to be transported from the powder outlet 11 to the combustion chamber of the test engine.

[0045] The structure diagram of the variable curve powder storage section stable powder supply device is as follows Figure 2 The powder supply device includes a powder storage cover 1, a powder supply gas inlet 2, a slider 3, a fluororubber soft plate 4, a powder storage section housing 5, a powder storage section 6, a fixing screw 7, a nut 8, a bolt 9, a fluidizing chamber 10, a powder outlet 11, a fluidizing gas inlet 12, a fluidizing chamber housing 13, a guide rail 14, a square stopper 15, a powder supply gas outlet 16, a solenoid valve 17 and a gas pressure sensor 18.

[0046] The fluororubber soft plate 4 fits tightly with the guide rail 14, and the fluororubber soft plate 4 can move freely on the guide rail 14. The powder supply gas enters the powder storage section shell 5 from the powder supply gas inlet 2 on the powder storage cover 1. Under the push of the pressure difference force, the slider 3 and the fluororubber soft plate 4 move together on the guide rail 14, pushing the powder body to move downstream. The fluidizing gas enters the fluidizing chamber 10 from the fluidizing gas inlet 12, and the fluidizing gas drives the powder to be transported from the powder outlet 11 to the combustion chamber. There are 4 guide rails 14, which are evenly distributed along the circumference. The fluidizing chamber 10 and the powder storage section 6, and the powder storage section 6 and the powder storage cover 1 are connected by bolts 9 and nuts 8.

[0047] There are four powder supply gas inlets 2 on the powder storage cover 1, which are cylindrical holes with threads on the outside for convenient sealed connection with the powder supply gas source; the powder storage cover 1 and the powder storage section shell 5, and the powder storage section shell 5 and the fluidizing chamber 10 are connected by bolts and nuts; the square block 15 is welded on the guide rail 14, and in order to prevent the slider 3 from falling off the guide rail 14, the slider 3 can move freely on the guide rail 14; the fixing screw 7 is used to fix the position of the guide rail 14 in the powder storage section shell 5; the powder outlet 11 and the fluidizing chamber 10 are processed as a whole; the solenoid valve 17 is connected to the powder supply gas outlet 16 pipeline to adjust the powder supply gas outlet flow rate.

[0048] In the figure, MFC is a gas mass flow meter for controlling the gas flow of powder supply gas and fluidizing gas; P is a gas pressure sensor 18 for measuring the powder supply gas pressure in the powder storage section; a mass sensor is installed at the bottom of the powder supply device to measure the total mass of the powder supply device in real time.

[0049] The functions of the fluororubber soft plate 4 include: 1. assisting in pushing the powder. The fluororubber soft plate 4 is in contact with the powder axially and in contact with the powder storage section shell 5 circumferentially. Under the action of the pressure difference force, the powder is pushed to move, playing a similar role to the piston in the piston pushing the powder structure; 2. preventing gas penetration and forming a high-pressure area on the powder supply gas side; 3. preventing powder overflow and preventing the powder from overflowing upstream.

[0050] Figure 3 The sectional view of the AA section shows the position and structure of the guide rail 14 and the slider 3. There are 4 guide rails 14, which are evenly distributed along the circumference of the powder storage section 6 and fixed to the powder storage section housing 5 by fixing screws 7. The cross section of the guide rail 14 is similar to a "convex" shape, and the large contact area with the bottom increases the stability of the connection between the guide rail 14 and the powder storage section housing 5. Each guide rail 14 is fixed to the powder storage section housing 5 by four fixing screws 7.

[0051] Preliminary experimental verification shows that the fluidizing gas blowing direction forms a 45° angle with the axis, at which time the fluidization effect is optimal.

[0052] The change of the powder supply gas pressure in the powder storage section is controlled by the solenoid valve 17 and the flow rate of the powder supply gas inlet 2, so as to keep the gas source pressure of the powder supply gas high and the powder supply gas pressure in the powder storage section lower than the gas source pressure. When the powder supply gas pressure in the powder storage section needs to be increased, a certain flow rate of powder supply gas is introduced through the powder supply gas inlet 2; when the powder supply gas pressure in the powder storage section needs to be reduced, some gas is discharged through the solenoid valve 17 to reduce the pressure.

[0053] In order to achieve a stable supply of powder, the advancement speed of the fluororubber soft plate 4 is controlled by the powder supply gas pressure of the powder storage section. The control method is: keep the powder supply gas source at a high pressure, under the condition that the cross section of the powder storage section 6 remains unchanged, the greater the powder supply gas pressure of the powder storage section, the greater the advancement speed of the fluororubber soft plate 4. When the fluororubber soft plate 4 moves to the position where the cross section of the powder storage section 6 changes, if it is necessary to control the advancement speed of the fluororubber soft plate 4, it is achieved by changing the powder supply gas pressure of the powder storage section. To obtain the same advancement speed, the pressure should be greater when the cross section area of ​​the powder storage section 6 is smaller.

[0054] In this example, an arc-shaped gap appears on the upper part of the powder storage section 6, and the gap part can provide space for the remaining systems of the aircraft to meet the special needs of the remaining systems. The pressure of the powder supply gas source and the fluidizing gas source is 5MPa, the initial flow rate of the powder supply gas is 50L / min, and the fluidizing gas flow rate is maintained at 100L / min.

[0055] The present example discloses a stable powder supply device suitable for a variable curve powder storage section, comprising the following operating steps:

[0056] Step 1: Fill the powder storage section 6 with aluminum powder to ensure that the powder is as uniform as possible in the circumferential direction, install the fluororubber soft plate 4 and fix it with the guide rail 14 in the circumferential direction, ensure that the fluororubber soft plate 4 is sealed with the inner wall of the powder storage section housing 5, and install the slider 3 so that the slider 3 and the fluororubber soft plate 4 can move freely on the guide rail 14;

[0057] Step 2: The powder storage cover 1 is sealed to the powder storage section 6, and a quick connector and a hose are used to ensure a sealed connection between the powder supply gas source and the powder supply gas inlet 2;

[0058] Step 3: Close the solenoid valve 17, fill the powder storage section 6 with powder supply gas, set the powder supply gas flow rate to 50L / min, the powder supply gas pressure in the powder storage section 6 increases, and the slider 3 and the fluororubber soft plate 4 move toward the powder end

[0059] Step 4: Fluidizing gas is introduced from the fluidizing gas inlet 12, the fluidizing gas flow rate is 100L / min, and powder conveying begins. When the fluororubber soft plate 4 has not entered the arc section, the powder supply gas flow rate is maintained at 50L / min, and the solenoid valve 17 is adjusted so that the powder supply gas pressure is 5atm. When entering the arc section, the powder supply gas flow rate is increased at a uniform speed, so that when the fluororubber soft plate 4 moves to the minimum cross-sectional position, the powder supply gas flow rate reaches 70L / min, and the solenoid valve 17 is combined to make the powder supply gas pressure reach 7atm at this time; when the fluororubber soft plate 4 continues to move, the powder supply gas flow rate is uniformly reduced, gradually from 70L / min to 50L / min, and the powder supply gas pressure becomes 5atm, and the powder supply gas flow rate is maintained at 50L / min until the powder supply is completed.

[0060] Step 5: After the powder supply is completed, the powder supply gas and fluidizing gas sources are turned off, and the solenoid valve 17 is closed.

[0061] Under the powder supply gas flow rate and pressure of step 4, the advancement speed of the fluororubber soft plate 4 is related to the cross-sectional area of ​​the powder storage section 6. When the cross-sectional area is the largest, the advancement speed is 3 mm / s, and when the cross-sectional area is the smallest, the advancement speed is 2.2 mm / s.

[0062] During the operation of the device. A mass sensor is used to measure the mass of the powder supply device, and the signal is converted and transmitted to the computer through an acquisition card to obtain a curve of the sum of the mass of the powder supply device and the mass of the powder supply gas changing with time during the powder supply stage. The sum of the initial mass of the powder supply device and the mass of the powder supply gas is divided by the mass of the powder supply gas and the mass of the powder supply device to obtain a curve of the conveying amount changing with time. The real-time mass flow rate of the powder conveying amount of the powder supply device is obtained by derivation of time. It is found that the mass flow rate is stably maintained at 40g / s, and the mass flow rate value is consistent with the value calculated by the formula. The device described in this example can achieve continuous and stable conveying of fine metal particles to meet the powder supply demand.

[0063] Embodiment 2:

[0064] This example uses 20μm to 30μm aluminum particles as fuel, high-pressure nitrogen as powder supply gas and fluidizing gas, and a powder storage section with a variable diameter structure to supply powder fuel to the combustion chamber of the test engine. The powder delivery rate is required to be basically maintained at 50g / s. Figure 4 Schematic diagram of the stable powder supply method for the variable diameter powder storage section. Figure 5 This is the structural diagram of the variable diameter powder storage section stable powder supply device, and the AA section view is as follows Figure 3 As shown, the cross section of the device described in Example 1 Figure 1 The powder delivery method and device structure are similar to those described in Example 1.

[0065] In this example, the powder storage section 6 is a large diameter to small diameter structure, and the small diameter section can provide space for other systems. The pressure of the powder supply gas source and the fluidizing gas source is 5MPa, the initial flow rate of the powder supply gas is 80L / min, and the fluidizing gas flow rate is maintained at 100L / min.

[0066] The present example discloses a stable powder supply device suitable for a variable diameter powder storage section, comprising the following operating steps:

[0067] Step 1: Fill the powder storage section 6 with aluminum powder to ensure that the powder is as uniform as possible in the circumferential direction, install the fluororubber soft plate 4 and fix it with the guide rail 14 in the circumferential direction, ensure that the flexible membrane 4 is sealed with the inner wall of the powder storage section housing 5, and install the slider 3 so that the slider 3 and the fluororubber soft plate 4 can move freely on the guide rail 14;

[0068] Step 2: The powder storage cover 1 is sealed to the powder storage section 6, and a quick connector and a hose are used to ensure a sealed connection between the powder supply gas source and the powder supply gas inlet 2;

[0069] Step 3: Close the solenoid valve 17, fill the powder storage section 6 with powder supply gas, set the powder supply gas flow rate to 80L / min, the powder supply gas pressure in the powder storage section 6 increases, and the slider 3 and the fluororubber soft plate 4 move toward the powder end

[0070] Step 4: Introduce fluidizing gas from the fluidizing gas inlet 12, the fluidizing gas flow rate is 100L / min, and powder conveying begins. When the fluororubber soft plate 4 is in the large diameter section, maintain the powder supply gas flow rate at 80L / min, and adjust the solenoid valve 17 so that the powder supply gas pressure is 8atm. When entering the gradient section, increase the powder supply gas flow rate at a uniform speed so that when the fluororubber soft plate 4 moves to the small diameter section, the powder supply gas flow rate reaches 60L / min, and the solenoid valve 17 is combined to make the powder supply gas pressure reach 6atm at this time; when the fluororubber soft plate enters the small diameter section, maintain the powder supply gas flow rate at 60L / min, and the powder supply gas pressure is 6atm until the powder supply ends.

[0071] Step 5: After the powder supply is completed, the powder supply gas and fluidizing gas sources are turned off, and the solenoid valve 17 is closed.

[0072] Under the powder supply gas flow rate and pressure of step 4, the advancement speed of the fluororubber soft plate is related to the cross-sectional area of ​​the powder storage section 6. In the large diameter section, the advancement speed is 4 mm / s, and in the small diameter section, the advancement speed is 3 mm / s.

[0073] During the operation of the device. A mass sensor is used to measure the mass of the powder supply device, and the signal is converted and transmitted to the computer through an acquisition card to obtain a curve of the sum of the mass of the powder supply device and the mass of the powder supply gas changing with time during the powder supply stage. The sum of the initial mass of the powder supply device and the mass of the powder supply gas is divided by the mass of the powder supply gas and the mass of the powder supply device to obtain a curve of the conveying amount changing with time. The real-time mass flow rate of the powder conveying amount of the powder supply device is obtained by derivation of time. It is found that the mass flow rate is stably maintained at 50g / s, and the mass flow rate value is consistent with the value calculated by the formula. The device described in this example can achieve continuous and stable conveying of fine metal particles to meet the powder supply demand.

[0074] The above description further illustrates the objects, methods, devices and advantages of the present invention in detail. It should be understood that the above description is only the specific implementation process of the present invention, which is used to explain the present invention and is not used to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A powder supply method for a stable powder supply device of a variable cross-section powder storage section, characterized in that: The pressure difference between the powder supply gas pressure in the powder storage section and the target environmental pressure is used to push the flexible dense membrane to move, driving the slider to move on the guide rail to ensure that the flexible dense membrane is always in contact with the powder body, and the flexible dense membrane pushes the powder to move downstream; under the push of the flexible dense membrane, fluidizing gas is introduced into the fluidizing chamber to fluidize the powder, driving the powder to be discharged from the outlet; The powder storage section has an irregular cross-section; a plurality of slide rails are arranged along the inner wall of the powder supply device; the flexible dense membrane is connected to the slide rail on the circumferential outer side and is fixed at the end of the slide rail, that is, fixed at the end of the powder supply device; the powder supply gas enters the powder storage section from the powder supply gas inlet of the powder storage cover, and forms a small pressure difference inside the upstream of the powder storage section, pushing the slider to move; under the action of the pressure difference between the powder supply gas pressure in the powder storage section and the target environmental pressure, the flexible dense membrane moves downstream to push the powder; the movement of the slider on the slide rail ensures that the flexible dense membrane is always in contact with the powder body, and the slider, the flexible dense membrane and the powder move together.

2. A powder supply method for a stable powder supply device of a variable cross-section powder storage section as claimed in claim 1, characterized in that: The powder storage section is a powder storage section with an irregular cross section.

3. A powder supply method for a stable powder supply device of a variable cross-section powder storage section as claimed in claim 1, characterized in that: The powder supply gas is the gas that enters the powder storage section through the powder supply gas inlet of the powder storage section, which is used to drive the movement of the powder body, and the gas source of the powder supply gas is high-pressure gas; the fluidizing gas is the gas that enters the fluidizing chamber through the fluidizing gas inlet of the fluidizing chamber, which is used to fluidize the powder, and the gas source of the fluidizing gas is high-pressure gas.

4. A powder supply method for a stable powder supply device of a variable cross-section powder storage section as claimed in claim 1, characterized in that: The flexible dense film is a film with a certain thickness, a tearing force of ≥10MPa, a high pressure resistance of ≥8MPa, and does not allow gas to pass through; the thickness of the flexible dense film is not less than 10mm.

5. A powder supply method for a stable powder supply device of a variable cross-section powder storage section as claimed in claim 1, characterized in that: There are four guide rails, which are evenly distributed along the circumference of the powder storage section. The fluidizing chamber is the place where the fluidizing gas fluidizes the powder. There are four fluidizing chamber inlets evenly distributed around the circumference. The direction of the fluidizing gas blowing is at an angle to the axis of the powder supply device. After the high-speed fluidizing gas enters the fluidizing chamber, it drives the powder in the fluidizing chamber to rotate and flow to the powder outlet with the fluidizing gas.

6. A powder supply method for a stable powder supply device of a variable cross-section powder storage section as claimed in claim 1, characterized in that: A mass sensor is installed in the powder supply device. The mass sensor is connected to the computer through an acquisition card. The real-time powder delivery amount during the powder supply process can be obtained through calculation.

7. A powder supply method for a stable powder supply device of a variable cross-section powder storage section as claimed in claim 1, characterized in that: By replacing the fluidizing chamber to change the convergence angle of the fluidizing chamber and the powder outlet diameter, changing the device structure size, adjusting the powder supply gas pressure, adjusting the fluidizing gas pore size, and the fluidizing gas flow rate, accurate control of the powder delivery amount and sufficient fluidization can be achieved.

Images