Rotary feeder for bulk material without pulsations

Abstract

Rotary feeder for bulk material without pulsation, consisting of a cylindrical body with an inlet and outlet and an outlet trough adjacent to the outlet of the cylindrical body, having an assembly of rotor on a driving shaft located in the cylindrical body, which contains at least two chambers separated by rotor blades, wherein the outlet trough is provided on one side with a conveying gas inlet and on the other side with a outlet cone mouthing into a conveying pipe with the axis of the conveying pipe, wherein the axis of rotation (8) of the rotor (7) forms with the axis of the conveying pipe (14) in the projection onto the horizontal plane (11) an angle y in the range of 5° to 45°, the axis of the inlet (15) with the axis of rotation (8) of the rotor assembly (7) in the projection onto the horizontal plane (11) forms an angle β in the range of - 45° to 45°, and the axis (16) of the outlet trough (5) is deflected relative to the axis of rotation of the rotor (8) in projection onto the horizontal plane (11) by an angle (i)o of 5° to 45°.

Description

Rotary feeder for bulk material without pulsationsTechnical field

[0001] The invention relates to a rotary feeder for bulk material, in particular alternative fuel.State of the art

[0002] Document US 2022 / 0380146 presents a rotary feeder that follows the outlet of a material dispenser, which contains a housing with a rotor assembly mounted on a shaft and with blades arranged around its circumference that create chambers into which the poured material is transferred to a trough below the rotor. In front of the trough is the inlet of the conveying gas, which carries the material through the conveying pipe to the gas outlet. The axis of the trough is therefore parallel to the axis of the drive of the rotor. In such an arrangement, undesirable pulses are generated when the material passes through the rotor, caused by the opening and thus emptying of the chamber along its entire length at once.

[0003] Document EP 4458743A1 presents a rotary feeder for transporting bulk materials in a pneumatic transport system, which follows to the outlet of a material dispenser, which is housed in a cylindrical body and has multiple chambers divided by blades, where the base of the trough-shaped drum is oriented at an angle between 2° and 45° from the inlet of the pipe of the conveying gas to the bottom of the drum to the drum outlet, so that the trough under the feeder is oriented at an angle along its entire axial length. This solution facilitates the smooth discharge of material from the feeder into the trough and further into the outlet pipe, but even here, undesirable pulses are generated during the passage of material through the rotor, caused by the opening and thus emptying of the chamber along its entire length at once.

[0004] Rotary feeder is a subsequent device that connects to the outlet of a bulk material dispenser, which is the subject of, for example, documents EP 2375226 B1 or EP 2748568 B1.

[0005] The aim of the invention is to introduce a rotary feeder that would enable to eliminate the material pulses during feeding into pneumatic pipe.Summary of the invention

[0006] The above-mentioned shortcomings are eliminated by a rotary feeder for bulk material without pulsation according to the invention, the essence of which is described incharacterizing part of the claim one. Preferred embodiments are mentioned in dependent claims.Brief description of drawings

[0007] The invention will now be presented using drawings, in which Fig. 1 shows a perspective view of the feeder according to the invention, Fig. 2 is a section through the rotary feeder from Fig. 1 by a horizontal plane, Fig. 3 illustrates a view from below of a section in the feeder trough through a horizontal plane, Fig. 4 is a view of the feeder from below, Fig. 5 is a top view of the feeder, Fig. 6 illustrates a perspective view of the uncovered rotor with blades, and Fig. 7 shows a perspective view of the rotor with the shaft.Preferred embodiments of the invention

[0008] Fig. 1 shows a rotary feeder consisting of a cylindrical body 2 with a material inlet 3 and an outlet trough 5, which is connected on one side to a conveying gas supply 18 and on the other side to an outlet cone 22, which continues to a subsequent conveying pipe 17, where the processed material is carried by the conveying gas for further use. A horizontal plane 11 is shown, to which the structural elements described below will relate. A drive shaft with a drive unit 23 passes through the cylindrical body 2.

[0009] Fig. 2 illustrates a cross-section through horizontal plane 11 of the rotary feeder, where the outlet trough 5 located in the lower part of the cylindrical body 2 can be seen. The axis 16 of the outlet trough 5 is deflected relative to the axis of rotation of the rotor 8 by an angle ω of 5° to 45°, preferably 20°. This angle is clearly visible in Fig. 3, which is a bottom view of the cut in the trough by the horizontal plane 11. This design allows a more even distribution of material into the conveying gas stream.

[0010] Fig. 4 shows a bottom view of the feeder 1. The axis of rotation 8 of rotor 7 forms with the axis of conveying pipe 14 in the projection onto the horizontal plane 11 an angle y in the range of 5" to 45°, preferably 20°. The angle of the axis 16 of the outlet trough 5 forms an with the axis of the conveying pipe 14 in the projection onto the horizontal plane 11 angle 6 in the range of 0° to 10\

[0011] The advantage of this solution is a reduction in the pulsation of the mixture of conveying gas and material in the conveying pipe 17, which results in a more stable flame on the burner behind the conveying pipe 17 and thus a more stable combustion process with minimized emissions when dosing bulk fuel and mixture of conveying gas into the burner.

[0012] Fig. 5 illustrates top view of the rotation of the material inlet 3 relative to the axis of rotation of the rotor 8. The axis of the inlet 15 and the axis of rotation 8 of the rotor assembly 7 form an angle p in the range of -45° to 45’ when projected onto the horizontal plane 11, which results in improved filling of the rotor 7 due to the fact that the falling input material, falling for example from the screw conveyor in larger clumps, is divided into at least two chambers 9 of the rotor 7 of the rotary feeder, due to which the filling of the rotor 7 is more uniform, which has a positive effect on reducing pulsation. This is also related to the blowing off air from the returning empty chamber 9 of the rotor 7 with a pressure higher than atmospheric pressure, due to overpressure in the conveying pipe 17, into the inlet space 3 with a pressure lower than that in the conveying pipe 17, which is usually approximately atmospheric pressure. In this defined pressure equalization space, where due to the rotation of the inlet 3 the transition edge 20 is not parallel to the blade 10 of the rotor 7, the chamber 9 is gradually opened from the side, which results in improved filling of the chamber 9 when dosing light material, which would otherwise be blown off into the space where it can be sucked in by the filter removing this exhaust air or enter chamber 9 of the rotor 7 of the feeder 1 closer to the cutting edge 19, which can cause local accumulation of material and, in extreme cases, can lead to the rotation stop of the rotary feeder 1.

[0013] Fig. 6 illustrates a perspective view of the uncovered rotor 7 with blades 10 forming individual chambers 9. The lower part also partially shows the inlet 12 of the conveying gas into the outlet trough 5, which is located symmetrically around the vertical plane passing through the axis 16 of the outlet trough, perpendicular to the horizontal plane 11. Individual axes can be seen here, such as the axis 8 of rotation of the rotor 7, the axis 14 of the conveying pipe 17, and the axis 15 of the inlet 3.

[0014] Fig. 7 shows a perspective view of the rotor 7 with the driving shaft 6 and blades 10. The advantage of rotating the conveying pipe 17 relative to the rotor axis 8 is that, the outlet trough 5 also creates a rotation of the shear edge 21 on the material outlet side, which reduces the risk of material shearing on the shearing edge 21 and thus also the frequency of potential blockages of the rotor 7 when transporting material with a higher content of larger parts.

[0015] Such rotation of shearing edges 19 and 21, more even filling and emptying of chambers is normally achieved by rotating blades 10 relative to the axis of rotation of rotor 8. The novelty of this solution is the rotation of axis 14 of conveying pipe 17, inlet 3 and outlet trough 5 relative to the axis of rotation of rotor 8. This solution has the above-mentioned functional advantages and also lower requirements for manufacturing of the rotor compared to a rotor with rotated blades and lower wear on the outlet cone 22.

[0016] Main advantages of the solution compared to the state of the art- More even material dosing on the outlet trough side into the conveying pipe - More even filling of chambers- Reduced risk of material shearing on the outlet trough side, thereby reducing the risk of rotor blockage- Defined blow-off point of the returning chamber, resulting in better filling of the chambers when conveying materials with low bulk density on the material inlet side - Reduced requirements on manufacturing of the rotor.

[0017] List of reference signs:1 Rotary feeder2 Cylindrical body3 Material inlet4 Outlet of the cylindrical body5 Outlet trough6 Driving shaft7 Assembly of rotor8 Rotation axis of rotor9 Chamber10 Rotor blade11 Horizontal plane12 Inlet of conveying gas into the trough13 Outlet edge14 Axis of the conveying pipe15 Inlet axis16 Axis of the outlet trough17 Conveying pipe18 Feed of conveying pipe19 Shear edge on the material inlet side20 Transition edge21 Shear edge on the material outlet side22 Outlet cone23 Drive unit

Claims

Claims1. Rotary feeder for bulk material without pulsation, consisting of a cylindrical body with an inlet and outlet and an outlet trough adjacent to the outlet of the cylindrical body, having an assembly of rotor on a driving shaft located in the cylindrical body, which contains at least two chambers separated by rotor blades, wherein the outlet trough is provided on one side with a conveying gas inlet and on the other side with an outlet cone mouthing into a conveying pipe with the axis of the conveying pipe, characterized in that the axis of rotation (8) of the rotor (7) forms with the axis of the conveying pipe (14) in the projection onto the horizontal plane (11) an angle y in the range of 5° tc 45“, the axis of the inlet (15) with the axis of rotation (8) of the rotor assembly (7) in the projection onto the horizontal plane (11) forms an angle p in the range of - 45“ to 45°, and the axis (16) of the outlet trough (5) is deflected relative to the axis of rotation of the rotor (8) in projection onto the horizontal plane (11) by an angle w of 5“ to 45°.

2. Rotary feeder according to claim 1, characterized in that the angle between the axis (16) of the outlet trough and the axis of the conveying pipe (14) in projection onto the horizontal plane (11) i s <5 in the range of 0cto 10°.

3. Rotary feeder according to claim 1 or 2, characterized in that the inlet of the conveying gas (12) is located symmetrically around a vertical plane passing through the axis (16) of the outlet trough, perpendicular to the horizontal plane (11).

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