RU2475709C1 - Method for volumetric dosing of powders, and device for its implementation - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: powder from a bin is charged under action of gravity force and torsional vibrations of the disc to spaces between blades, which form chambers. Besides, blades 3 vibrate due to torsional vibrations of the disc and provide more complete powder filling of the space between them. Then, due to disc rotation the powder in the above chambers moves in a circular direction to the outlet channel, where it is fully unloaded to it from each chamber under action of gravity force and vibration of the blades.

EFFECT: increasing uniform supply of such loose powders and simplifying the design of the device.

14 cl, 2 dwg

Description

FIELD OF TECHNOLOGY

The invention relates to means for dispensing and uniform distribution of low-flowing materials from a source or reservoir, more specifically to dispensers with rotating intake-dosing elements with measuring (measured) chambers, and is intended for uniform controlled delivery of low-flowing materials, for example, powders.

The invention can be used in any industries where dosing of low-flowing powdery materials is used, prone to clumping and sticking to walls.

BACKGROUND OF THE INVENTION

Dosing and uniform distribution of powders is often carried out by metering feeders with a mechanical dosing system, by filling the powder with a number of small measuring chambers (volumes) of the intake-dosing element, followed by unloading of this powder into the outlet channel.

Dosing of finely divided bulk materials in this way is difficult, since they are prone to clumping and sticking to the walls of the hopper, measuring chambers (volumes, grooves, blades, holes) and other surfaces. Such powders do not always completely fill the measuring chambers (volumes), which leads to uneven supply of powder into the outlet channel.

For the dosing and uniform dispensing of finely ground materials through the use of small measuring chambers, it is necessary to solve complex technological and design problems: ensuring forced uniform and continuous outflow of bulk materials and powders from the feed hoppers, completely filling the measuring chambers (volumes) with powder, maintaining the same powder density in the volume of each measuring chamber, eliminating the influence of the height of the powder backfill in the hopper, overcoming sticking to the walls of low-flowing powders and loose materials when unloading from measuring chambers, etc.

For more efficient emptying of the measuring chambers from the powder, processes of its blowing or exhausting are often used. However, for powders prone to adhering to the walls of the measuring chambers, these methods are also not always effective. This is due to the fact that after removal by the carrier gas stream from the measuring chamber of the bulk powder, a sufficiently large space appears for this stream, free of powder and suitable for the free passage of the carrier gas stream. In this case, the powder adhering to the walls easily flows around the carrier gas stream, since there is a lot of free space for such a flow in the measuring chamber after removal of the bulk of the powder.

To solve this problem, use the vibration of the entire housing of the metering device [RU 100236, IPC G01F 11/00, G01F 13/00, 2010, U1; RU 2221222, 2001, IPC G01F 11/18, C2], various mechanical elements are used to mix the powder in the hopper and to completely fill the measuring chambers [JP 2010065246, 2010, IPC C23C 14/24, A; JP 2002362752,2001, IPC B01B 7/18; B65D 88/08, A]. However, this complicates the design and for low-flowing powders is not always effective.

In addition, the tendency of small powders to stick to the surface of the walls of the measuring chambers leads to incomplete release of the chambers from the powder when it is independently spilled from the chambers. To reduce the effect of this drawback, powder exhaustion from measuring chambers is used [JP 4564153, IPC B65G 53/42; B65G 53/46, 2002, B2], blowing it off with a carrier gas stream [RU 92362, IPC B05B 7/14, G01F 13 / 00,2009, U1] or mechanical wiping (extrusion, scraping) [JP 10297747, IPC B65G 47 / 18, 1997, B2; JP 5007469, IPC A23L 1/16, 1991, A]. It also complicates the design and limits the use of these methods and devices.

Closest to the claimed solution is a device [RU 2227273, IPC G01F 11 / 00,2003, C2], in which volumetric dosing of powders includes the sequential filling of identical measuring chambers of the intake-metering element with powder, its rotation and unloading of the powder into the exhaust channel.

Dosing of powder in this way is carried out by the device,

comprising a hopper, an intake-metering element mounted rotatably around its axis and made in the form of a disk with measuring chambers located at its periphery, and at least one outlet channel located under the intake-metering element.

The main disadvantage of this method is the uneven supply of low-flowing materials, due to incomplete filling of the measuring chambers with powder from the hopper and its incomplete discharge into the exhaust channel due to partial sticking of the powder to the walls of the measuring chambers.

SUMMARY OF THE INVENTION

The objective of the proposed solution is to increase the uniformity of the flow of bulk powders (powder materials) into the exhaust channel by providing more complete filling of the measuring chambers with powder and its complete discharge from them, and simplifying the design of the device.

The problem is solved in that in the known method of volumetric dosing of powders, which includes sequential filling of identical measuring chambers of the intake-metering element with powder, its rotation and unloading of the powder into the outlet channel, simultaneously with the rotation, torsional vibrations of the intake-metering element are made relative to the axis of its rotation. Unloading of powder from the measuring chambers can be carried out by either exhaustion, or blowing, or natural rash. The most uniform powder filling from the hopper of the same measuring chambers (volumes) in the rotating intake-metering element will occur if torsional vibrations and rotation of the intake-metering element are performed, providing its alternately multidirectional rotation around the axis so that the average angle of rotation in different directions is different .

The problem will also be solved if, in the known device containing the hopper, the intake-metering element in the form of a disk mounted rotatably around its axis, with measuring chambers located at its periphery, and at least one located under the intake-metering element the outlet channel, the intake-metering element will be installed on the bottom of the hopper with the possibility of torsional vibrations around the axis of its rotation, and will be equipped with a node that provides rotation and torsional vibrations, while the outlet the channel will be made at the bottom of the hopper.

Measuring chambers can be made in the form of holes on the periphery of the disk or in the form of spaces (volumes) between the blades located on the periphery of the disk, while the blades can be located in the plane of the disk either radially or at an angle to the radius of the disk passing through the blade.

To facilitate the movement (pouring down) of the powder in the hopper to the measuring chambers on the disk, a cone of a smaller diameter (smaller diameter so as not to overlap the measuring chambers) can be additionally rigidly fixed upside down with fixed elements for mixing the powder in the hopper.

A stepping motor with a control unit capable of alternately multidirectional rotation of the motor axis by one or several steps can be used as a unit providing rotation of the intake-dosing element, and the average number of steps in one direction should not be equal to the average number of steps in the other direction.

A comparative analysis with the prototype showed that the claimed solution is characterized in that at the same time as the rotation, torsional vibrations of the intake-metering element are produced relative to the axis of its rotation. To do this, the intake-metering element in the form of a disk is mounted on the bottom of the hopper with the possibility of torsional vibrations around the axis of its rotation, and is equipped with a node that provides rotation and torsional vibrations, while at least one outlet channel is made in the bottom of the hopper, which allows to judge compliance the criterion of "novelty."

A comparative analysis with other solutions in this area did not reveal technical solutions containing features that match the distinguishing features of the claimed invention, which allows us to judge whether the criterion of "inventive step" is met.

The invention consists in the following.

As is known, when bulk dosing of powders, to ensure the accuracy of dosing and uniformity of the powder supply, it is necessary that all the chambers of the intake-dosing element always have the same amount of powder loaded, and then all the powder is surely poured out (unloaded, removed) completely from each measuring chamber in the outlet channel.

For low-flowing powders, meeting both of these requirements in practice is a significant problem.

The fact is that when filling the measuring chamber, the powder usually comes from the hopper located above the measuring chamber under its own weight. In this case, the loose-flowing and prone to clumping powder enters the measuring chamber not in the form of a homogeneous medium, but in the form of lumps of one size or another. Since, due to the continuous movement of the intake-metering element, the filling time of the measuring chamber is always limited, the lumps of powder that have fallen into the measuring chamber do not have time to compact to a homogeneous mass and cavities that are not filled with powder remain in the volume of the measuring chamber. In this case, the volume of powder in each measuring chamber becomes less than the total volume of the chamber, and this difference is not a constant, but a random variable. Naturally, an unequal amount of powder in each metering chamber leads to an uneven supply of powder into the exhaust channel.

On the other hand, when emptying the measuring chamber from a loose powder, this powder may partially adhere to the walls of the measuring chamber. This process is also random and the amount of powder remaining in the volume of the measuring chamber is not constant. Thus, the amount of powder supplied per unit time to the outlet channel per unit time is not constant, but depends on the random process of powder sticking to the walls of the measuring chambers.

The technical methods used in the known methods and devices for volumetric dosing of powders, such as mixing the powder in the hopper, using mechanical elements to force the powder into the measured measurements, vibration of the entire dispenser body or its hopper, of course, contribute to a more complete filling of the measuring chambers, but far not always and not fully.

The proposed method for dispensing powder differs from the known ones in that an additional operation is introduced - torsional vibration of the intake-dosing element containing measuring chambers. In this case, vibration is attached to the walls of the measuring chambers (with the oscillation frequency of the intake-dosing element).

The vibration of the walls of the measuring chambers significantly accelerates the process of filling the measuring chambers with powder from the hopper, while ensuring the filling of the entire volume of each measuring chamber. Thus, in each measuring chamber of the same volume will be the same amount of powder.

When powder is unloaded from measuring chambers, vibration of their walls sharply reduces the likelihood of powder sticking to their walls and ensures complete removal of powder from each measuring chamber. In this case, the powder from the measuring chambers can naturally pour out or forcefully blow out or suck out into the exhaust channel.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is illustrated by drawings, where in Fig.1 is a schematic illustration of the proposed device for volumetric dosing of powders that implements the inventive method of volumetric dosing. Figure 2 shows a horizontal section of the proposed device at the disk level along the axis A-A.

The device comprises a hopper 1 mounted on its bottom intake-metering element 2, made in the form of a disk, with measuring chambers located on its periphery, which are made in the form of volumes 3, limited by the blades 4 (figure 2). An exhaust channel 5 is made under the intake-metering element, over which a visor 6 with an opening 7 is located, preventing direct powder precipitation from the hopper into the exhaust channel. To facilitate the movement of the powder in the hopper down to the measuring chambers on the disk, the cone 8 is firmly fixed with its top upward, on which there are elements 9 for mixing the powder in the hopper during rotation and vibration of the cone together with the disk. The disk 2 is equipped with a node 10 that performs rotation and torsional vibrations of the intake-metering element.

MODE FOR CARRYING OUT THE INVENTION

The implementation of the invention can be demonstrated by the example of a dispenser with an intake-dispensing element in the form of a disk 2 with blades 4 located on its periphery (Fig. 2). The disk is located on the bottom of the hopper 1 with a flat bottom, containing at least one hole 5 in the bottom, which is the outlet for the powder. The exhaust channel is located under the blades of the disk, and above the blades at the location of the exhaust channel there is a visor 6, which prevents direct precipitation of powder from the hopper into the exhaust channel.

The disk is rigidly fixed on the axis of the stepper motor, which with the help of the engine control unit provides torsional vibrations of the disk, which are alternating multidirectional rotation of the disk around the axis by a small angle. The rotation of the disk (gradual rotation in one of the directions) is carried out by providing a different average angle of rotation of the disk in one and the other directions.

Powder from the hopper under the influence of its own weight falls into the spaces between the blades, the space between which is a measuring chamber. Due to the torsional vibrations of the disk, the blades vibrate. Due to the vibration of the blades, which are actually the walls of the measuring chambers, the powder quickly fills the entire space between the blades, i.e. completely fills the volume of each measuring chamber.

Next, the powder between the blades moves these blades together with the disk parallel to the bottom of the hopper. Then each portion of the powder between the blades moves under the visor and is separated from above by the visor from the total mass of powder in the hopper (the powder from the hopper can no longer enter the space between the blades located under the visor). When a portion reaches the outlet channel in the form of an opening in the bottom of the hopper, the powder from the measuring chamber (from the space between the blades) falls under its own weight into the outlet channel. Vibration of the blades prevents powder from sticking to the blades (i.e., the walls of the metering chambers), thus ensuring complete emptying of each metering chamber.

A device that implements this method works as follows.

Powder from the hopper 1 under the influence of gravity and torsional (vibration) vibrations of the disk 2 is poured into the space between the blades 3 (the movement of the powder is shown by an arrow). These spaces between the blades form measuring chambers 4. Moreover, due to the presence of torsional vibrations of the disk 2, the blades 3 vibrate and provide full filling of the space between them with powder.

Further, due to the rotation of the disk 2, the powder in the measuring chambers is moved by the blades in a circle to the exhaust channel 5, where it is completely poured into it from each measuring chamber under the action of gravity and vibration of the blades 3 (the movement of the powder is shown by an arrow).

To prevent direct precipitation of powder from the hopper into the outlet channel, a visor 6 is located above this channel, adjacent to the upper edge of the disk and blades. Through an additional opening 7 in the visor 6, the unloading of bulk material from the metering chambers can be carried out by additional blowing of the powder into the exhaust channel 5. If there is a vacuum in the exhaust channel 5, the emptying of the metering chambers from the powder can be further improved due to the suction of the powder.

The rotation and torsional vibrations of the blade with blades are carried out using the node 10, on the axis of which the disk is fixed. It is advisable to perform this assembly in the form of a stepper motor, the control unit of which provides alternating multidirectional rotation of the motor axis by one or several steps, and the average number of steps in one direction is not equal to the average number of steps in the other direction. In this case, the average speed of rotation of the disk with the blades will be determined by the difference between the number of engine steps in one and the other directions per unit time.

Claims (14)

1. A method for volumetric dosing of powders, comprising sequentially filling the measuring chambers of the intake-metering element with powder, its rotation and unloading the powder into the exhaust channel, characterized in that torsional vibrations of the intake-metering element are produced simultaneously with the rotation relative to the axis of rotation. 2. The method of dispensing powders according to claim 1, characterized in that the discharge of powder from the measuring chambers is carried out by exhaustion. 3. The method of dispensing powders according to claim 1, characterized in that the discharge of powder from the measuring chambers is carried out by blowing. 4. The method of dispensing powders according to claim 1, characterized in that the discharge of powder from the measuring chambers is carried out by natural rashes. 5. The method of dispensing powders according to claim 1, characterized in that the movement of the intake-dispensing element is produced, providing its alternately multidirectional rotation around the axis so that the average angle of rotation in different directions is different. 6. A device for volumetric dosing of powders, containing a hopper, an intake-metering element in the form of a disk with measuring chambers located on its periphery, mounted for rotation around its axis, and located at least one outlet channel under the intake-metering element, characterized in that the intake-metering element is installed on the bottom of the hopper with the possibility of torsional vibrations around the axis of rotation and is equipped with a node that provides rotation and torsional vibrations, while the exhaust channel is made in no bunker. 7. The device according to claim 6, characterized in that the measured cameras are made in the form of holes in the disk. 8. The device according to claim 6, characterized in that the measuring chambers are made in the form of spaces between the blades located on the periphery of the disk. 9. The device according to claim 8, characterized in that the blades are located on the periphery of the disk radially. 10. The device according to claim 8, characterized in that the blades are located in the plane of the disk at an angle to the radius of the disk passing through the blade. 11. The device according to claim 6, characterized in that the cone of a smaller diameter with the top upwards is additionally rigidly fixed to the disk. 12. The device according to claim 11, characterized in that the elements for mixing the powder in the hopper are fixed on the cone. 13. The device according to claim 6, characterized in that a stepper motor with a control unit is used as a node providing movement of the intake-metering element. 14. The device for dispensing powders according to claim 13, characterized in that a control unit is used that provides alternate multidirectional rotation of the motor axis by one or several steps, and the average number of steps in one direction is not equal to the average number of steps in the other direction.

Images