Continuous metering and conveying system for trace powder

Abstract

The utility model discloses a continuous metering and conveying system for trace powder. The continuous metering and conveying system comprises a storage bin, a stirring assembly, a metering panel, a material thickness adjusting assembly and a material conveying assembly, an arc-shaped notch is formed in one side of a bottom plate of the storage bin; the metering panel can rotate horizontally, an annular metering groove is formed in the top face of the metering panel, and a feeding position, a discharging position and a feeding position are sequentially distributed on the metering groove in the rotating direction. The metering panel positioned between the feeding position and the discharging position extends into the storage bin; the material thickness adjusting assembly is arranged on the inner side wall of the storage bin right above the discharging position and can adjust the height of the material in the metering tank; the stirring assembly comprises stirring blades which can be in sliding contact with the top surface of the metering tank; the material conveying assembly is arranged over the material supply position and can block, adsorb and convey materials in the metering groove located in the material supply position to a material using point. The material thickness can be adjusted, it is guaranteed that the rotating speed of the rotating motor is not lower than 10% P, and then motor stability, material pile density stability and material filling rate stability are guaranteed.

Description

TECHNICAL FIELD

[0001] The utility model relates to a material metering conveying device, in particular to a trace powder continuous metering conveying system. BACKGROUND

[0002] The trace material mentioned in the application refers to the material with the conveying amount less than 100g / h, such as the additive with small usage amount. In the continuous use of the trace material, the metering of the trace material is often involved. The current metering method mainly uses the loss-in-weight scale with the rotating screw to meter. However, the minimum metering capacity of this metering method is more than 1kg / h, and there is no reasonable metering scheme when the usage amount is less than 100g / h. In addition, the loss-in-weight scale has the following problems when metering the trace powder:

[0003] 1. Poor stability of the motor: when the conveying amount of the trace material is small, in order to accurately meter, the rotating speed of the rotating motor driving the screw is usually reduced to less than 5%P. P is the rated rotating speed of the rotating motor. However, when the rotating speed of the rotating motor is less than 5%P, the conveying stability will be poor, and the material blocking phenomenon is easy to occur.

[0004] 2. Unstable bulk density and filling rate of the material: when the conveying amount of the trace material is small, the bulk density and filling rate of the material are required to be high. When the bulk density and filling rate fluctuate, the conveying stability of the trace material will fluctuate greatly. In the prior art, it is difficult to obtain stable bulk density and filling rate of the material because the shape of the filled material of the rotating screw is complex and the size is small. CONTENT OF THE UTILITY MODEL

[0005] The utility model solves the technical problem in view of the above-mentioned deficiency of the prior art, and provides a trace powder continuous metering conveying system. The trace powder continuous metering conveying system can adjust the thickness of the material, and ensure that the rotating speed of the rotating motor is not less than 10%P, thereby ensuring the stability of the motor, the stability of the bulk density of the material, and the stability of the filling rate of the material.

[0006] To solve the above technical problem, the utility model adopts the following technical scheme:

[0007] A trace powder continuous metering conveying system, comprising a storage bin, a stirring assembly, a metering disc, a material thickness adjusting assembly, and a material conveying assembly.

[0008] The storage bin is used to store the material to be continuously metered and conveyed, and an arc-shaped notch is formed on one side of the bottom plate of the storage bin.

[0009] The metering disc can rotate horizontally, and an annular metering groove is arranged on the top surface of the metering disc. The metering groove is sequentially provided with an inlet position, an outlet position, and a feeding position along the rotating direction.

[0010] The metering disc is extended into the storage bin between the feeding position and the discharging position, the side wall of the metering disc can be sealingly and slidably matched with the arc-shaped gap, and the top surface of the metering disc is sealingly and slidably matched with the bottom surface of the side wall of the storage bin at the arc-shaped gap.

[0011] The thickness adjusting assembly is arranged on the side wall of the storage bin directly above the discharging position, and includes a lifting plate with a height capable of being lifted, and the bottom of the lifting plate can be extended into the metering groove directly below and adjust the height of the material in the metering groove.

[0012] The stirring assembly is coaxially arranged in the storage bin and includes a stirring shaft and stirring blades arranged on the bottom of the stirring shaft in a circumferential direction; the stirring blades can rotate under the driving of the stirring shaft and can be in sliding contact with the top surface of the metering groove.

[0013] The material conveying assembly is arranged directly above the feeding position and can block, adsorb and convey the material in the metering groove at the feeding position to the use position.

[0014] The bottom upstream side wall surface of the lifting plate is provided with a thickness adjusting arc.

[0015] The bottom downstream side wall surface of each stirring blade is provided with a stirring adjusting arc.

[0016] The bottom surface of the metering disc is provided with a rotating motor at the center, and the rotating motor is used to drive the horizontal rotation of the metering disc; the rotating speed of the rotating motor is not less than 10%P; wherein P is the rated rotating speed of the rotating motor.

[0017] The total length of the arc-shaped gap is not less than one third of the circumference of the metering disc.

[0018] The top surface of the metering disc is flush with the top surface of the bottom plate of the storage bin.

[0019] The material conveying assembly includes a material inlet directly above the feeding position, and the downstream bottom side wall of the material inlet is provided with an arc-shaped baffle extended into the metering groove, and the arc-shaped baffle can block the material in the metering groove at the feeding position.

[0020] The material conveying assembly includes a Venturi conveying pipe and an air conveying assembly.

[0021] The Venturi conveying pipe includes a core rod, a columnar head and a discharging pipe.

[0022] The core rod is hollow, and the hollow cavity is formed as the material inlet.

[0023] The top of the core rod is protruded to form a protruding part, and a plurality of equal-length air injection grooves are uniformly arranged on the outer periphery of the protruding part in a circumferential direction; wherein each air injection groove is in a spiral type.

[0024] The columnar head and the discharging pipe are sequentially arranged from bottom to top.

[0025] The center of the columnar head is sequentially arranged from bottom to top with an air distribution cavity, a conical cavity and an inner material outlet channel; wherein, the inner diameter of the air distribution cavity is larger than the inner diameter of the inner material outlet channel, and is connected and transitioned through the conical cavity; the air distribution cavity is sealingly matched with the protruding part of the core rod.

[0026] The center of the discharge pipe is provided with an outer material outlet channel; the outer material outlet channel and the inner material outlet channel jointly form an equal-diameter material outlet.

[0027] The air conveying assembly is used for conveying compressed air to all the air injection grooves.

[0028] The air conveying assembly comprises a compressed air inlet and a gas storage cavity.

[0029] The gas storage cavity is arranged on the outer periphery of the core rod and is in communication with the bottom of each air injection groove, and the top of each air injection groove is in communication with the conical cavity.

[0030] The cross-sectional shape of each air injection groove is square or semicircular.

[0031] The utility model has the following beneficial effects:

[0032] 1、The bottom of the lifting plate in the material thickness adjusting assembly can extend into the metering groove directly below, and the height of the material in the metering groove is adjusted. Further, the upstream sidewall surface of the bottom of the lifting plate is provided with a material thickness adjusting arc, which can guide the material in the metering groove at the discharge position upward to rise, avoid the compaction of the material by stirring, and further ensure the stability of the bulk density of the material in the metering groove.

[0033] 2、The application adjusts the thickness of the material in the metering groove, and further ensures that the rotating motor has a speed not lower than 10%P; wherein, P is the rated speed of the rotating motor. When the transmission amount of the trace material is small, that is, the rotating motor speed needs to be reduced to below 5%P by the traditional method, the application reduces the height of the lifting plate, and further reduces the thickness of the material in the metering groove, and further ensures that the rotating motor has a speed not lower than 10%P, usually between 20%P and P. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 A whole view of the trace powder continuous metering and conveying system is shown.

[0035] Figure 2 A top view of the trace powder continuous metering and conveying system is shown.

[0036] Figure 3 A three-dimensional simulation half-section view of the trace powder continuous metering and conveying system is shown.

[0037] Figure 4A three-dimensional perspective view of the micro-powder continuous metering and conveying system is shown.

[0038] Figure 5 A partial three-dimensional plan view of the micro-powder continuous metering and conveying system is shown.

[0039] Figure 6 A partial enlarged schematic view of the material thickness adjusting arc and the arc-shaped baffle is shown.

[0040] Figure 7 A three-dimensional simulation half-section view of the material conveying assembly is shown.

[0041] Figure 8 An enlarged schematic view of the lower shell in the material conveying assembly is shown.

[0042] Among them:

[0043] 10. storage bin; 11. arc-shaped notch;

[0044] 20. stirring assembly; 21. stirring shaft; 22. stirring motor; 23. stirring paddle; 231. stirring adjusting arc;

[0045] 30. metering disc; 31. rotary motor; 32. metering groove; 321. feeding position; 322. discharging position; 323. feeding position;

[0046] 40. material thickness adjusting assembly; 41. lifting plate; 42. material thickness adjusting arc;

[0047] 50. material conveying assembly;

[0048] 510. upper shell; 520. lower shell;

[0049] 530. Venturi conveying pipe;

[0050] 531. core rod; 5311. material inlet; 5312. air injection groove;

[0051] 532. columnar head; 5321. air distribution cavity; 5322. conical cavity; 5323. inner material outlet passage;

[0052] 533. discharging pipe; 5331. outer material outlet passage;

[0053] 540. air conveying assembly; 541. compressed air inlet; 542. air communication cavity; 543. air storage cavity. DETAILED DESCRIPTION

[0054] The utility model will be further explained in detail in combination with the drawings and specific preferred embodiments.

[0055] In the description of the utility model, it needs to be understood that the orientation or positional relationship indicated by the terms "left side", "right side", "upper part", "lower part" and the like is the orientation or positional relationship based on the drawings shown, and is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element indicated must have a particular orientation, be constructed and operated in a particular orientation, and "first", "second" and the like do not represent the importance of the parts, so it cannot be understood as a limitation on the utility model. The specific size adopted in the embodiment is only for the purpose of illustrating the technical scheme, and does not limit the protection scope of the utility model.

[0056] As shown in Figure 1 and Figure 5 , a kind of continuous metering conveying system of trace powder, including storage bin 10, stirring assembly 20, metering disc 30, material thickness adjusting assembly 40 and material conveying assembly 50.

[0057] Storage bin is used to store the material to be continuously metered and conveyed, and the bottom plate of the storage bin is provided with an arc-shaped notch 11 on one side.

[0058] The stirring assembly is coaxially arranged in the storage bin, including a stirring shaft 21, a stirring motor 22 and a stirring paddle 23. Among them, the stirring paddle is circumferentially arranged at the bottom of the stirring shaft, and can rotate synchronously with the stirring shaft under the drive of the stirring motor.

[0059] As shown in Figure 3 , the bottom downstream side wall surface of each stirring paddle is horizontally provided with a stirring adjusting arc 231. The setting of the stirring adjusting arc 2 can guide the material at the bottom of the storage bin upwards and surge, avoiding the compaction of the material by stirring, and further ensuring the stability of the bulk density of the material in the storage bin.

[0060] In this application, the stirring shaft speed is preferably not less than 1.5 times the speed of the metering disc, to ensure that the material at each point of the metering groove can be stirred when passing through the storage bin.

[0061] Further, the bottom surface of each stirring paddle is preferably in sliding cooperation with the top surface of the bottom plate of the storage bin.

[0062] The bottom surface of the above-mentioned metering disc is provided with a rotating motor 31, and the rotating motor is used to drive the horizontal rotation of the metering disc.

[0063] The top surface of the metering disc is provided with an annular metering groove 32, and the metering groove is sequentially provided with a feeding position 321, a discharging position 322 and a feeding position 323 along the rotation direction.

[0064] The metering disc between the feeding position and the discharging position extends into the storage bin, that is, the metering groove and the bottom surface of the storage bin at the arc-shaped notch have two intersection points, and the two intersection points sequentially form the feeding position and the discharging position along the rotation direction of the metering disc.

[0065] The side wall of the metering disc can be in sealing sliding fit with the arc-shaped gap, and the top surface of the metering disc can be in sealing sliding fit with the bottom surface of the side wall of the storage bin at the arc-shaped gap.

[0066] In the present application, the top surface of the metering disc is flush with the top surface of the bottom plate of the storage bin, so that the bottom surface of the stirring paddle can be in sliding contact with the top surface of the metering groove when the stirring paddle rotates, thereby ensuring the filling rate and the bulk density of the material in the metering groove.

[0067] Further, the present application can adjust the length of the metering groove (i.e. the length of the metering groove filled with material) between the feeding position and the discharging position according to the continuous conveying speed of the trace amount of material to be measured. In the present embodiment, the length of the metering groove filled with material is controlled by controlling the length of the arc-shaped gap. The total length of the arc-shaped gap is preferably not less than one third of the circumference of the metering disc, and in this case, the length of the metering groove filled with material is not less than one third of the total circumference of the metering groove.

[0068] The thickness-adjusting assembly is arranged on the inner side wall of the storage bin directly above the discharging position, and the thickness-adjusting assembly comprises a lifting plate 41 which can be lifted in height. The lifting of the lifting plate is known in the art, and can be motor-driven or manually driven. In the present application, the lifting of the lifting plate is manually driven in order to minimize the disturbance to the material in the storage bin. That is, the lifting plate is detachably mounted on the inner side wall of the storage bin directly above the discharging position.

[0069] The bottom of the lifting plate can extend into the metering groove directly below and adjust the height of the material in the metering groove. Further, the upstream side wall surface of the bottom of the lifting plate is provided with a thickness-adjusting arc 42 as shown in Figure 6 The thickness-adjusting arc is preferably horizontally arranged and has the same width as the metering groove. The arrangement of the thickness-adjusting arc can direct the material in the metering groove at the discharging position to surge upwards, thereby avoiding the compaction of the material by stirring and ensuring the stability of the bulk density of the material in the metering groove.

[0070] In the present application, the thickness of the material in the metering groove is adjusted, thereby ensuring that the rotational speed of the rotating motor is not less than 10% P; wherein P is the rated rotational speed of the rotating motor. When the transmission amount of the trace amount of material is small, i.e. the rotational speed of the rotating motor needs to be reduced to less than 5% P according to the conventional method, the present application can ensure that the rotational speed of the rotating motor is not less than 10% P, usually between 20% P and P, by reducing the height of the lifting plate and thereby reducing the thickness of the material in the metering groove.

[0071] The material conveying assembly is arranged directly above the feeding position and can block, adsorb and convey the material in the metering groove at the feeding position to the use position.

[0072] As shown in Figure 7 and Figure 8 , the material conveying assembly comprises an upper housing 510, a lower housing 520, a Venturi conveying pipe 530 and an air conveying assembly 540.

[0073] The upper shell and the lower shell are coaxially and detachably connected, preferably through flange thread connection.

[0074] The Venturi conveying pipe is arranged on the central axis of the upper shell and the lower shell, and includes a core rod 531, a columnar head 532 and a discharge pipe 533.

[0075] The core rod is preferably integrally arranged on the central axis of the lower shell and is hollow, and the hollow cavity is formed as a material inlet 5311, which is located directly above the feeding position, as shown in the figure. Figure 6 As shown, the lower downstream side wall of the material inlet is provided with an arc-shaped baffle plate 5313 extending into the metering groove, which can block the material in the metering groove at the feeding position.

[0076] The top of the core rod is protruded to form a protruding portion, and the outer periphery of the protruding portion is uniformly provided with not less than 4 equal-length air injection grooves 5312 in the circumferential direction; in the embodiment, the number of the air injection grooves 312 is preferably 4, and the cross-sectional shape of each air injection groove is preferably square or semicircular, etc., so that the area of the compressed air contacting the parts is minimized as far as possible under the condition of ensuring the flow area, and the viscous resistance of the gas flowing through the place is also minimized.

[0077] Further, each air injection groove is in a spiral shape, and the spiral lead angle of each air injection groove is preferably 30-50°. By such arrangement, the introduced compressed air forms a cyclone-shaped forward airflow, and the rotating airflow does not form adhesion with the inner wall of the material outlet, reducing the loss of trace material.

[0078] Further, the length of each air injection groove is preferably 5-8 times the maximum dimension of the cross-sectional shape interface, which is as short as possible under the condition of realizing the guiding function. When the cross-sectional shape of the air injection groove is square, the maximum dimension of the interface is the length of the diagonal; when the cross-sectional shape of the air injection groove is semicircular, the maximum dimension of the interface is the diameter.

[0079] The columnar head and the discharge pipe are sequentially arranged on the central axis of the upper shell from bottom to top.

[0080] The center of the columnar head is sequentially provided with an air distribution cavity 5321, a conical cavity 5322 and an inner material outlet passage 5323 from bottom to top; wherein the inner diameter of the air distribution cavity is larger than the inner diameter of the inner material outlet passage, and the transition is connected through the conical cavity; the air distribution cavity is sealingly matched with the protruding portion of the core rod.

[0081] The center of the discharge pipe is provided with an outer material outlet passage 5331; the outer material outlet passage and the inner material outlet passage jointly constitute an equal-diameter material outlet. Among them, the material outlet is preferably connected with a material end container through a pipeline connection, and the tail gas is discharged through a filter.

[0082] Further, the inner diameters of the material inlet and the material outlet are preferably equal.

[0083] The air delivery assembly comprises a compressed air inlet 541, an air communication cavity 542 and an air storage cavity 543.

[0084] The air storage cavity is arranged at the top of the lower shell outside the core rod, and is preferably open at the top surface. A sealing assembly is arranged outside the air storage cavity to seal the air storage cavity.

[0085] The compressed air inlet is horizontally arranged outside the middle part of the columnar head, and the air communication cavity is vertically arranged to communicate the compressed air inlet and the air storage cavity. The absolute pressure P0 at the compressed air inlet is preferably in the range of 300000-400000 Pa, and the compressed air inlet is preferably connected to the compressed air through a filter pressure reducing valve.

[0086] The bottom of each air jet slot is preferably communicated with the air storage cavity, and the top of each air jet slot is communicated with the conical cavity.

[0087] The sum of the cross-sectional areas of all the air jet slots is S, in m 2 ; and the calculation formula of S is:

[0088] S = Av * 60 * 1000 / 454 / P0 (293 / T0) 0.5 )

[0089] Wherein:

[0090] P / P0 < 0.528

[0091] In the formula, A is the cross-sectional area of the material outlet, in m 2 .

[0092] v is the gas flow rate at the end of the material outlet, in m / s.

[0093] P0 is the absolute pressure at the compressed air inlet, in Pa.

[0094] T0 is the stagnation temperature of the air in the air storage cavity, in K.

[0095] P is the absolute pressure at the end of the material outlet, in Pa.

[0096] Since P / P0 < 0.528, the speed of the air flowing through the air jet slot is sonic flow. By using the Venturi principle, a negative pressure is formed at the starting end of the material inlet of the core rod, and a positive pressure as large as possible is formed at the delivery end of the delivery pipe.

[0097] In this application, by setting the sum S of the cross-sectional areas of all the air jet slots, the gas flow rate v at the end of the material outlet is controlled in the range of 20-30 m / s, and the absolute pressure P at the end of the material outlet is not more than 131 Kpa.

[0098] In the micro material conveying process, the compressed air source pressure is stabilized at 3-4 bar, the jet slot sprays the rotating airflow in the sonic state and forms a negative pressure to completely suck the micro material at the material inlet and convey it to the material using point. The material speed through the discharge pipe is controlled at 20-30 m / s, and the tail end of the discharge pipe has a larger positive pressure, so that the resistance drop at the Venturi conveying rear end is not greater than 30 kPa when the conveying distance is not greater than 30 m, and stable conveying can be realized.

[0099] Further, since the material speed through the discharge pipe is controlled at 20-30 m / s, stable long-distance conveying is ensured, and since the speed is small, the micro material conveyed by the material using point will not adhere to the filter core of the filter, thereby further reducing the loss of micro material, and in addition, there is no material adhesion dead angle, so that the feed amount and the discharge amount are equal, and the stability of the formula can be ensured.

[0100] In the present application, when the micro material continuous metering conveying is started, the air source of the material transmission assembly is opened first, then the stirring motor and the rotating motor are started, the material starts to enter the metering groove of the metering disc and is uniformly taken out of the storage bin, and when it reaches the material supply position, it is blocked by the arc-shaped baffle and conveyed to the material using point. The material is weighed for 10 min at the material using point to obtain the continuous metering mass flow at the current thickness position of the material thickness adjusting assembly and the current rotating speed of the rotating motor, and in turn, the required mass flow can be obtained by adjusting the rotating speed of the rotating motor.

[0101] The preferred embodiments of the present application are described in detail above, but the present application is not limited to the specific details in the above embodiments, and various equivalent transformations of the technical solutions of the present application can be made within the technical concept of the present application, and these equivalent transformations all belong to the protection scope of the present application.

Claims

1. A continuous metered delivery system for a fine powder material, characterized by: The continuous metering and conveying device comprises a storage bin, a stirring assembly, a metering disc, a material thickness adjusting assembly and a material conveying assembly. The storage bin is used for storing material to be continuously metered and conveyed. The bottom plate of the storage bin is provided with an arc-shaped notch on one side. The metering disc can rotate horizontally and is provided with an annular metering groove on the top surface. The metering disc is arranged in the storage bin between the feeding position and the discharging position. The side wall of the metering disc can be sealingly and slidably connected with the arc-shaped notch. The material thickness adjusting assembly is arranged on the inner side wall of the storage bin above the discharging position.

2. The continuous micro-powder mass metering delivery system according to claim 1, characterized in that: The material thickness adjusting assembly comprises a lifting plate which can be lifted and lowered.

3. The continuous micro-powder mass metering delivery system of claim 1, wherein: The bottom of the lifting plate can extend into the metering groove below and adjust the height of the material in the metering groove.

4. The continuous micro-powder mass metering delivery system of claim 1, wherein: The stirring assembly is coaxially arranged in the storage bin and comprises a stirring shaft and stirring blades arranged on the bottom of the stirring shaft.

5. The continuous micro-powder mass metering delivery system of claim 1, wherein: The stirring blades can rotate under the driving of the stirring shaft and can be in sliding contact with the top surface of the metering groove.

6. The continuous micro-powder mass metering delivery system of claim 1, wherein: The material conveying assembly is arranged above the feeding position and can block, adsorb and convey the material in the metering groove at the feeding position to a material use position.

7. The continuous micro-powder feed system of claim 1, wherein: The bottom of the lifting plate is provided with a material thickness adjusting arc on the upstream side wall.

8. The continuous micro-powder mass metering delivery system of claim 7, wherein: The bottom of each stirring blade is provided with a stirring adjusting arc on the downstream side wall. The bottom surface of the metering disc is provided with a rotating motor. The rotating speed of the rotating motor is not less than 10% of the rated rotating speed. The total length of the arc-shaped notch is not less than one third of the circumference of the metering disc. The top surface of the metering disc is flush with the top surface of the bottom plate of the storage bin. The material conveying assembly comprises a material inlet above the feeding position. The downstream bottom side wall of the material inlet is provided with an arc-shaped baffle extending into the metering groove. The arc-shaped baffle can block the material in the metering groove at the feeding position.

9. The continuous micro-powder mass metering delivery system of claim 8, wherein: The material conveying assembly comprises a Venturi conveying pipe and an air conveying assembly. The Venturi conveying pipe comprises a core rod, a columnar head and a discharging pipe.

10. The continuous micro-powder mass metering delivery system of claim 8, wherein: The core rod is hollow and the hollow cavity forms a material inlet. The top of the core rod is protruded to form a protruded part. A plurality of equal-length air injection grooves are uniformly arranged on the outer periphery of the protruded part. Each air injection groove is in a spiral shape. The columnar head and the discharging pipe are sequentially arranged from bottom to top. The center of the columnar head is sequentially provided with an air distribution cavity, a tapered cavity and an inner material outlet channel from bottom to top. The inner diameter of the air distribution cavity is larger than that of the inner material outlet channel and is connected and transitioned through the tapered cavity. The air distribution cavity is sealingly connected with the protruded part of the core rod. The center of the discharging pipe is provided with an outer material outlet channel. The outer material outlet channel and the inner material outlet channel jointly form an equal-diameter material outlet. The air conveying assembly is used for conveying compressed air into all air injection grooves. The air conveying assembly comprises a compressed air inlet and a gas storage cavity. The gas storage cavity is arranged on the outer periphery of the core rod and is in communication with the bottom of each air injection groove. The top of each air injection groove is in communication with the tapered cavity. The cross section of each air injection groove is in a square or semicircular shape.

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