WO2023128814A1

WO2023128814A1 - Feed throat for screw conveyor devices

Info

Publication number: WO2023128814A1
Application number: PCT/RU2022/050204
Authority: WO
Inventors: Игорь Феликсович ШЛЕГЕЛЬ
Original assignee: Игорь Феликсович ШЛЕГЕЛЬ
Priority date: 2021-12-27
Filing date: 2022-06-27
Publication date: 2023-07-06
Also published as: RU2771476C1

Abstract

The invention relates to the building materials industry. A feed throat for screw conveyor devices comprises an inlet tube mounted on a cylindrical housing in which a screw conveyor is disposed. In the feed region, in a direction counter to the rotation of the screw conveyor, the housing widens toward a feed opening and mates with a vertical side wall of the tube, said wall being offset from the edge of the screw conveyor toward the centre thereof by an amount equal to 0.1-0.2 of the radius of the screw conveyor. The radius of the widening is equal to 1.1-1.3 of the radius of the screw conveyor. The line of the start of the widening lies below the axis of the screw conveyor such that a perpendicular extended from the axis toward said line forms an angle of 40-50º with the horizontal. The side wall of the tube which is oriented toward the rotation of the screw conveyor is inclined outwards by an angle of 20-40º to the vertical. A line of connection of the inclined wall with the housing lies below the axis of the screw conveyor such that a perpendicular extended from the axis of the screw conveyor to said line forms an angle of 20-40º with the horizontal. This increases the productivity and operational reliability of a screw conveyor device by preventing material from sticking to the walls of the feed throat.

Description

LOADING SPOUT OF SCREW DEVICES

The field of technology to which the invention belongs

SUBSTANCE: invention relates to building materials industry and can be used for supplying sticky material to screw mixers and screw presses for plastic molding of ceramic products.

State of the art

A screw mixer is known from the prior art (see ed. St. SU 927288, MIC: B01F7/08, publ. 15.05.1982), which includes an auger located in the housing, inlet and outlet pipes.

A press for molding ceramic products is known (see ed. St. SU 1701530, MIK: V28VZ/22, publ. 12/30/1991), containing a body placed in the body of an auger connected to a drive, as well as a loading nozzle and a molding head.

In known devices, during operation, the ceramic mass sticks to the side walls of the loading pipe, mainly to the wall opposite to the rotation of the screw. The mass adhering to the walls forms visors above the auger, narrowing the section of the loading pipe, through which the mass is fed to the auger. As a result, loading of the auger with mass worsens, which leads to a decrease in productivity and a decrease in the operational reliability of the equipment. In addition, in the receiving funnel located above the loading pipe, the process of arch formation occurs, which also leads to a decrease in the reliability of the device.

Partially, these shortcomings are eliminated in a screw press (see ed. St. SU 1036545, IPC: V28VZ / 22, publ. 08/23/1983), containing a boot device with a toothed feed roll, a housing with a mouthpiece and an auger located in the housing connected to a drive . The axis of the gear roll is equipped with blades, the length of which is limited by the screw rotation surface. The blades clean the front and side walls of the loading chamber from the sticking mass, however, the presence of a toothed feed roll, rotated by the rotation of the screw, leads to a significant increase in energy consumption.

For the prototype, a loading neck of a device for grinding and mixing plastic materials, mainly clay (see patent for invention RU 2297324, IPC: B28C1 / 14, publ. 20.04.2007), containing a pipe with vertical walls mounted on a cylindrical body, in which auger is located. The disadvantage of the prototype is to reduce the performance of the device due to sticking of the material on the walls of the filler neck, narrowing its cross section.

Disclosure of invention

The claimed invention solves the problem of increasing the productivity and operational reliability of the screw device by eliminating the sticking of material on the walls of the loading neck.

The problem is solved due to the fact that in the loading neck of the screw devices, containing a pipe mounted on a cylindrical housing in which the screw is located, according to the claimed invention, the housing in the loading zone from the side opposite to the rotation of the screw is made with an expansion towards the pipe, with a radius , equal to 1.1-1.3 of the screw radius, is associated with a vertical side wall of the nozzle, shifted from the edge of the screw to its center by an amount equal to 0.1-0.2 of the screw radius, and the expansion start line is located below the screw axis in this way that the perpendicular drawn from the axis to this line forms an angle of 40-50 ° with the horizontal.

The above set of essential features of the claimed invention made it possible to obtain the following positive technical results.

Firstly, when the screw device is used with materials prone to sticking, there is a gradual increase in the ceramic mass on the wall of the loading neck, which is opposite to the rotation of the screw. The mass adhering to the wall forms a kind of visor above the auger, narrowing the section of the loading neck, through which the mass is fed to the auger. As a result, it worsens loading the screw with mass, which leads to a decrease in productivity and a decrease in the operational reliability of the equipment. Due to the execution of the housing with an expansion towards the branch pipe, a gap is formed between the turns of the screw and the body in the loading zone, tapering wedge-shaped from top to bottom (from the branch pipe to the screw). The flights of the auger grab the material and feed it into the wedge-shaped gap. Due to the narrowing of the gap towards the screw, the material is pressed into the screw channel of the screw, completely filling its interturn space. At the same time, the vertical side wall of the nozzle does not interfere with the supply of material, which makes it possible to exclude the possibility of ceramic mass sticking to it. The optimum is the expansion radius equal to 1.1-1.3 screw radius. If the expansion radius is less than 1.1 of the auger radius, the gap between the auger turns and the body will be insignificant, the vertical side wall of the nozzle will be in the path of material movement, and it will not be possible to avoid sticking clay mass to it. When the expansion radius is greater than 1.3 of the screw radius, the initial gap between the screw turns and the body will be too large, which will lead to the formation of a dead zone along the inner surface of the body in the area of connection with the vertical side wall of the nozzle.

In addition, the vertical side wall of the nozzle is shifted from the edge of the screw to its center by an amount equal to 0.1-0.2 of the screw radius, which makes it possible to increase the initial gap between the screw and the housing, and ensures greater filling of the screw interturn space with mass. When the wall displacement value is less than 0.1 of the screw radius, structurally it is in the way of material movement and gradually overgrown with ceramic mass. When the wall displacement value is greater than 0.2 of the screw radius, the screw sector, which participates in the intake of material from the loading zone, narrows.

At the same time, the location of the expansion start line below the screw axis makes it possible to increase the filling of the screw interturn space with material. If the angle between the perpendicular drawn from the axis of the screw to this line and the horizontal is less than 40°, the sector for capturing material from the loading zone by the screw will decrease, therefore, the productivity of the device will decrease. At an angle greater than 50°, at the bottom of the loading area increases a gap between the turns of the screw and the inner surface of the body, leading to the formation of a dead zone in this place.

Thus, the above technical results together provide an uninterrupted supply of the ceramic mass to the screw and, therefore, improve the performance and operational reliability of the screw device.

Preferably, the side wall of the pipe, opposite to the rotation of the screw, is inclined outward at an angle of 20-40 ° relative to the vertical, and the line of its connection with the body is located below the axis of the screw so that the perpendicular drawn from the axis to this line is at an angle of 20- 40° to the horizontal. Due to this, the flow area of the loading pipe increases, and the filling of the interturn space of the screw is ensured.

When the angle of inclination of the side wall is more than 40°, the coefficient of friction of the bulk cargo against the walls of the branch pipe will be greater than the coefficient of internal friction of the load, which will make it difficult for the material to flow out of the branch pipe along the inclined wall by gravity. When the angle of inclination of the side wall is less than 20°, the flow section of the branch pipe is significantly narrowed.

If the angle between the perpendicular drawn from the axis of the auger to the connection line of the side inclined wall with the housing and the horizontal is greater than 40°, the angle of inclination of this wall relative to the vertical will increase accordingly. This will hinder the flow of material to the screw, and there will be stagnant zones in the feed neck. With a decrease in this angle less than 20°, the mass capture zone by the screw narrows, the filling of its interturn space decreases, therefore, the performance of the device decreases.

Brief description of the drawings

The essence of the proposed technical solution is illustrated by drawings, which show: in Fig. 1 - loading neck, cross section; in fig. 2 - loading neck, longitudinal section. Implementation of the invention

The loading neck of the screw devices contains a branch pipe 1 mounted on a cylindrical body 2, in which the screw 3 is located.

The housing 2 in the loading area from the side opposite to the rotation of the screw 3 is made with an extension (arc ac) towards the loading opening and is associated with a vertical side wall 4 of the nozzle. The expansion radius R2 ac is equal to 1.2 of the screw radius R.

R2 ⁼ 1.2 x Ri.

Wall 4 is displaced from the edge of the screw to its center by an amount I equal to 0.15 of the screw radius Ry.

1 = 0.15 x R],

The expansion start line is located below the screw axis in such a way that the perpendicular oa drawn from the axis to this line forms an angle 01 equal to 45° with the horizontal.

The side wall 5 of the pipe, opposite to the rotation of the screw 3, is inclined outward at an angle P, relative to the vertical, equal to 30°. The connection line of the wall 5 with the housing 2 is located below the axis of the screw in such a way that the perpendicular ob drawn from the axis to this line forms an angle y equal to 30° with the horizontal.

The front 6 and rear 7 walls of the nozzle 1 of the loading neck are located vertically.

The loading neck works as follows.

The feedstock enters the loading zone through the nozzle 1. The turns of the screw 3 capture the material and feed it into the gap between the screw 3 and the housing 2, formed by the expansion ac. In this case, the wall 4 of the pipe 1 does not prevent the rotation of the material, which makes it possible to exclude the possibility of ceramic mass sticking to it. Due to the narrowing of the gap towards the screw 3, the material is pressed into the screw channel of the screw, completely filling its interturn space, and transported in the body 2 of the device.

Thanks to the inventive loading neck, sticking of ceramic material to the walls is prevented, leading to overgrowth of its passage section and the formation of peaks above the screw, an uninterrupted supply of material to the screw is ensured, therefore, the operational reliability and productivity of the screw device are increased.

Claims

7

The loading neck of screw devices, containing a branch pipe mounted on a cylindrical housing in which the screw is located, characterized in that the housing in the loading area from the side opposite to the rotation of the screw is made with an expansion towards the branch pipe, with a radius equal to 1.1 - 1.3 of the screw radius, is associated with a vertical side wall of the nozzle, shifted from the edge of the screw to its center by an amount equal to 0.1-0.2 of the screw radius, and the expansion start line is located below the screw axis in such a way that the perpendicular drawn from axis to this line, forms an angle of 40-50 ° with the horizontal. The loading neck according to claim 1, characterized in that the side wall of the nozzle, opposite to the rotation of the screw, is inclined outward at an angle of 20-40 ° relative to the vertical, and the line of its connection with the body is located below the axis of the screw in such a way that the perpendicular drawn from the axis to this line forms an angle of 20-40° with the horizontal.

SUBSTITUTE SHEET (RULE 26)