WO2016071745A1

WO2016071745A1 - Device for charging viscous, pasty, sludgy and/or lumpy materials into a reactor

Info

Publication number: WO2016071745A1
Application number: PCT/IB2015/001992
Authority: WO
Inventors: Hans-Ulrich NEHM
Original assignee: Holcim Technology Ltd
Priority date: 2014-11-04
Filing date: 2015-10-27
Publication date: 2016-05-12
Also published as: AR102519A1; AT516432B1; AT516432A1

Abstract

In a device for charging viscous, pasty, sludgy and/or lumpy materials into a reactor (19), comprising a rotor (3) capable of being rotationally driven about an axis of rotation (4), a feed line (5) for feeding the material to the rotor (3), and a discharge opening (6) for discharging the material conveyed by the rotor (3), the rotor (3) is designed to be hollow enclosing a conveying chamber (7), and the feed line (5) opens into the conveying chamber (7) in the interior of the rotor (3), and the discharge opening (6) is disposed on the axial end of the rotor (3) located opposite the feed line (5).

Description

Device for charging viscous, pasty, sludgy and/or lumpy materials into a reactor

The invention relates to a device for charging viscous, pasty, sludgy and/or lumpy materials into a reactor such as a rotary kiln or calciner of a clinker production plant, including a rotor capable of being rotationally driven about an axis of rotation, a feed line for feeding the material to the rotor, and a discharge opening for discharging the material conveyed by the rotor. The invention further relates to the use of such a device for charging waste materials and/or alternative fuels into a cement clinker production process.

Waste materials and alternative fuels for use in a cement clinker production process usually occur in different states of matter and in different compositions. It is, for instance, known to convey lumpy waste materials such as used tires through suitable conveying means to the appropriate charging site at a rotary kiln of a clinker production plant, wherein the respective plant parts have to be adapted to the dimensions of used tires as well as the masses of such materials to be respectively fed in a reasonable manner. It is, furthermore, known to introduce sludges of different compositions into a reactor such as a unit of a cement clinker production plant, wherein such sludges are either free of solid, lumpy components or may contain such components. The sludges will, in particular, contain lumpy components if the waste materials occurring as solids are slurried in order to enhance their conveyability. By slurrying, the preferably disintegrated waste materials can be brought into a pumpable state.

Austrian Patent AT 504 452 Bl describes a method in which the raw materials are subjected to mechanical disintegration as slurries or in slurried form as pumpable masses, and the pumpable mass is ejected into the calciner and/or rotary kiln in ascending pipes. That method offers the advantage that the thus formed pumpable mass containing the waste materials and/or alternative fuels can be supplied to a relatively simple device for injecting the materials into a clinker production process, said device being substantially comprised of a tubular housing including a rotor that is rotationally mounted substantially concentrically with the tube axis and drivable for rotation and comprises blades sweeping the space between the shaft of the rotor and the wall of the housing, wherein a plurality of lines or openings are connected to the shell of the tubular housing, at least one line being offset relative to the sludge supply and at least one further line being offset in the peripheral direction. That simply structured, low-maintenance device enables both the disagglomeration and the disintegration of waste materials or alternative fuels by the blades or beating arms of the rapidly rotating rotor, the high kinetic energy transmitted by the rotor to the materials to be charged, at the same time, ensuring the injection of the materials into the clinker production process at a high speed.

The device according to this prior art is connected to a unit of a clinker production process via a discharge cone, the supply of the slurried waste materials or alternative fuels being effected from below in the installed position. That invention, however, involves the disadvantage of persistent caking of the sludgy masses or obstructions occurring in operation, thus reducing the delivery rate. Moreover, the blades or beating arms of that rotor are exposed to high mechanical stress such that high wear is to be observed.

The present invention, therefore, aims to provide a device of the initially defined kind, which provides the opportunity to load viscous, pasty, sludgy and/or lumpy materials having different compositions at different locations into a reactor such as a clinker production plant, wherein the risk of the formation of a bottleneck due to obstruction or baking is to be reduced. Furthermore, the susceptibility to wear is to be reduced.

To solve this object, the device of the initially defined kind according to the invention is substantially further developed such that the rotor is designed to be hollow enclosing a conveying chamber, and that the, in particular static, feed line opens into the conveying chamber in the interior of the rotor and the discharge opening is disposed on the axial end of the rotor located opposite the feed line. Unlike in the prior art, the material is thus conveyed not transversely to the axis of rotation of the rotor, but in an axial direction of the rotor, i.e. in the direction of the axis of rotation of the rotor. The material is thus not accelerated by the impulse generated as the beating arms hit the material, but it is primarily centrifugal forces that act on the material, pressing the latter at the inner periphery of the hollow rotor, where it is moved along in the axial direction. Due to the centrifugal force, the material is homogenized on the inner periphery of the rotor, wherein the axial transport towards the discharge opening of the rotor is achieved by the shape of its inner shell and by the pushing action of the succeeding material. The centrifugal force is caused by the charged material being set in rotation upon contact with the inner wall of the rotor, the acceleration of the material in the sense of a rotation being the higher the more cohesive/adhesive the material. In the event of viscous or sludgy material, a high rotational acceleration is usually to be observed, whereas this happens to a substantially lower extent with solid, in particular metallic, foreign material contained in the sludge. This effect results in that lumpy, solid foreign material contained in the sludge will slide over the rotor surface without substantially adopting the rotation of the same, while the sludge will be set in rotation to a considerably higher extent and will thus be accelerated. Thus, the foreign material receives less impuls and will simply fall into the reactor via the discharge opening, while the sludge is accelerated to a larger extent and is distributed in the reactor volume due to the action of the centrifugal force.

The ejection from the hollow rotor primarily takes place in the radial direction. Unlike with devices transporting the material at right angles to the rotor axes, a more effective feeding of sludge and the like into the reactor will thereby be ensured, while wear of the device and possible blockages within the device will be largely avoided.

The device according to the invention is preferably further developed to the effect that the inner wall bounding the conveying chamber, of the rotor widens towards the discharge opening, particularly in a conical or calotte-shaped manner. This will promote the axial transport within the rotor due to the centrifugal force. Alternatively, a rotor having an inner cross section that is substantially constant over the axial length of the rotor may be envisaged, the axial transport in this case being effected by the pushing action of the succeeding material.

The inner wall bounding the conveying chamber of the rotor may be designed to be circular or polygonal in terms of cross section. A polygonal configuration will promote the formation of a peripheral speed component of the material so as to increase the centrifugal force and the disagglomeration action.

The device according to the invention advantageously may, moreover, be further developed to the effect that the inner wall bounding the conveying chamber of the rotor comprises vanes protruding towards the conveying chamber, in particular ribs extending in the conveying direction or at acute angles thereto. Such vanes will ensure both the effective transport of the material to be homogenized and a correspondingly enhanced homogenization thereof, since additional force will be exerted on the material as the latter impinges on the vanes.

Provided the structural and other prerequisites are met, the material emerging from the rotor in the radial direction will immediately reach the reactor, thus causing a radial injection into the reactor. If an axial injection is desired, it is preferably provided that at least one deflection member having a deflection surface is arranged in the region of the discharge opening to deflect the material ejected from the rotor in the radial direction via the discharge opening. The deflection member imparts a deflection in the direction of the reactor interior to the material ejected from the rotor so as to ensure its distribution in the interior of the reactor.

In a preferred manner, it is provided that the deflection member is comprised of a ring surrounding the discharge opening and whose deflection surface extends in a manner inclined relative to the axis of rotation of the rotor, in particular conically.

The device according to the invention can, in particular, be configured to the effect that the deflection member is arranged to be static, i.e. not co-rotating, and, in particular, connected to a static housing of the device.

Alternatively, it may be provided that the deflection member is arranged concentrically with the rotor and rotationally about the axis of rotation, and is drivable for rotation either in the same direction as the rotor or in the counter direction. The deflection member can in this case be driven at. the same rotational speed as the rotor, or at a speed deviating therefrom, so as to provide an influence of the deflection behavior. The device according to the invention in this context is further developed to the effect that the deflection member cooperates with a rotational drive, said rotational drive comprising adjusting means for changing the rotational speed of the deflection member and/or for changing the direction of rotation. The appropriate speed can be selected as a function of the nature of the material.

It is preferably provided that the deflection surface of the deflection member is arranged at a radial distance from the edge of the discharge opening of the rotor.

Furthermore, it is preferably provided that the deflection surface of the deflection member is provided with inwardly protruding, preferably plate-shaped, guide profiles. This will enable a particularly effective directional manipulation of the material radially emerging from the rotor, in particular in configurations including a rotating deflection member.

The deflection surfaces of the guide profiles are preferably inclined relative to the axis of rotation at an angle of 30° to 60° .

The invention further relates to the use of the previously described device for charging viscous, pasty, sludgy and/or lumpy materials into a reactor and its use for charging waste materials and/or alternative fuels into a cement clinker production process and, in particular, a combustion unit, such as a rotary kiln or calciner, of a cement clinker production plant. In the following, the device according to the invention will be explained in more detail . by way of exemplary embodiments schematically illustrated in the drawing. Therein, Fig. 1 illustrates a first embodiment, Fig. 2 a second embodiment, and Fig. 3 a third embodiment, of the invention.

In Fig. 1, the device for charging viscous, pasty, sludgy and/or lumpy materials is denoted by 1. The device 1 comprises a hollow rotor 3, which is drivable for rotation about an axis of rotation 4. The device 1 comprises a, particularly static, feed line 5 for feeding the material into the interior of the rotor 3 and a discharge opening 6 for discharging the material conveyed by the rotor 3. The rotor 3 is designed to be hollow, enclosing a conveying chamber 7. The feed line 5, in the interior of the rotor 3, opens into the conveying chamber 7, and the discharge opening 6 opens into the reactor 2 on the axial end of the rotor 3 located opposite the feed line 5.

As is apparent from Fig. 1, the inner wall 8 bounding the conveying chamber 7, of the rotor 3 widens conically towards the discharge opening 6. The inner wall 8 of the rotor 3 may carry inwardly protruding vanes, in particular ribs 21 extending in the conveying direction or at acute angles thereto, as indicated by broken lines.

The device 1 in the region of the discharge opening β, moreover, comprises an annular deflection member 9 having a deflection surface 10 for deflecting the material ejected from the rotor 3 in the radial direction via the discharge opening 6 in the direction to the reactor 2. The deflection member 9 is comprised of a ring surrounding the discharge opening 6 and whose deflection surface 10 widens conically towards the reactor 2 in the axial direction. In the configuration according to Fig. 1, the deflection member 9 is connected to a static housing 11 of the device 1, thus not rotating along with the rotor 3.

The rotational drive for the rotor 3 is schematically denoted by 15 and comprises ball bearings 16 for rotationally mounting the rotor 3.

The device 1 is installed in the wall 17 of a reactor, the discharge opening 6 being substantially in alignment with the inner wall 18 of the reactor so as to enable the conveyed material to directly reach the interior 19 of the reactor.

The configuration according to Fig. 2 largely corresponds to the configuration according to Fig. 1, corresponding parts bearing identical reference numerals. As in contrast to the configuration according to Fig. 1, the annular deflection member 9 is rotationally mounted in the configuration according to Fig. 2, the axis of rotation 4 of the rotor 3 and that of the deflection member 9 being concurrent. The deflection member 9 is mounted via ball bearings 13. The rotational drive for the deflection member 9 is schematically denoted by 14.

An annular element 12 surrounds the rotor 3 closely behind the discharge opening 6. It serves to seal the bearing of the rotor 3 and reduce the intake of false air.

The configuration according to Fig. 3 differs from the configurations according to Figs. 1 and 2 in that no separate deflection member 9 is provided. The rotor 3 is calotte-shaped and does without deflection member, because the primarily radial acceleration of the material occurs in the steep portion of the calotte and the deflection into the interior 19 of the reactor takes place directly in the curve on the end of the calotte. In this construction, a preferably provided axial movability of the feed line 5 and/or the rotor 3 in the sense of arrow 20 is of particular advantage for achieving the optimum acceleration of the material (by moving the charging pipe relative to the calotte) and for ensuring the ejection of the material without, or with a minimum, impact of the material on the inner reactor wall 18 (by an axial movement of the rotor 3 itself) .

In this arrangement, it would be conceivable to attach fan blades to the rear wall of the rotor, which would aspirate external air and compress the same between the rotor 3 and the reactor wall 17 in order to thereby ensure the active injection of the sludge into the interior 19 of the reactor.

Claims

Claims :

1. A device for charging viscous, pasty, sludgy and/or lumpy materials into a reactor, comprising a rotor capable of being rotationally driven about an axis of rotation, a feed line for feeding the material to the rotor, and a discharge opening for discharging the material conveyed by the rotor, characterized in that the rotor (3) is designed to be hollow enclosing a conveying chamber (7), that the feed line (5) opens into the conveying chamber (7) in the interior of the rotor (3), and that the discharge opening (6) is disposed on the axial end of the rotor (3) located opposite the feed line (5).

2. A device according to claim 1, characterized in that the inner wall (8) bounding the conveying chamber (7), of the rotor

(3) widens towards the discharge opening (6) , particularly in a conical or calotte-shaped manner.

3. A device according to claim 1 or 2, characterized in that the inner wall (8) bounding the conveying chamber (7), of the rotor

(3) is designed to be circular or polygonal in terms of cross section .

4. A device according to claim 1, 2 or 3, characterized in that the inner wall (8) bounding the conveying chamber (7), of the rotor comprises vanes protruding towards the conveying chamber (7), in particular ribs (21) extending in the transport direction or at acute angles thereto.

5. A device according to any one of claims 1 to 4, characterized in that a deflection member (9) having a deflection surface (10) is arranged in the region of the discharge opening (6) to deflect the material ejected from the rotor (3) in the radial direction via the discharge opening (6).

6. A device according to claim 5, characterized in that the deflection member (9) is comprised of a ring surrounding the discharge opening (6) and whose deflection surface (10) extends in a manner inclined relative to the axis of rotation (4) of the rotor (3), in particular conically.

7. A device according to claim 5 or 6, characterized in that the deflection member (9) is connected to a static housing (11) of the device.

8. A device according to claim 6 or 7, characterized in that the deflection member (9) is arranged concentrically with the rotor (3) and rotationally about the axis of rotation (4), and is drivable for rotation.

9. A device according to claim 6, 7 or 8, characterized in that the deflection member (9) cooperates with a rotational drive (14) , said rotational drive comprising adjusting means for changing the rotational speed of the deflection member and/or for changing the direction of rotation.

10. A device according to any one of claims 5 to 9, characterized in that the deflection surface (10) of the deflection member (9) is arranged at a radial distance from the edge of the discharge opening (6) of the rotor (3) .

11. A device according to any one of claims 5 to 10, characterized in that the deflection surface (10) of the deflection member (9) is provided with inwardly protruding, preferably plate-shaped, guide profiles.

12. A device according to claim 11, characterized in that the deflection surfaces of the guide profiles are inclined relative to the axis of rotation at an angle of 30° to 60°.

13. A device according to any one of claims 1 to 12, characterized in that the outer wall of the rotor (3) facing away from the conveying chamber (7) carries peripherally distributed fan blades (21) .

14. The use of a device according to any one of claims 1 to 13 for charging viscous, pasty, sludgy and/or lumpy materials into a reactor.

15. The use of a device according to any one of claims 1 to 13 for charging waste materials and/or alternative fuels into a cement clinker production process and, in particular, a combustion unit, such as a rotary kiln or calciner, of a cement clinker production plant.