EP3871777A1 - Device for treating a mixture of materials consisting of substitute fuel and impurity - Google Patents

Abstract

The present invention relates to a device for processing a material mixture consisting of substitute fuel and impurities, having a vertically oriented central feed (1), a separating device (2) arranged below the central feed (1), a rotor mill (3), the rotor mill ( 3) is arranged above the separating device (2) and surrounds the central feed (1), a flow device (4) for generating an upwardly directed gas flow, the rotor mill (3) having several tools (8a, 8a, 8b).

Description

The present invention relates to a method for processing a material mixture consisting of substitute fuel and impurities, which is sifted, comminuted and dried in the device.

The substitute fuel, also known as secondary fuel, includes in particular solid waste, which can be used together with conventional fuels, especially in cement, lime, lignite or industrial power plants as well as in waste incineration plants or as the sole fuel in substitute fuel power plants. The solid waste, for example, consisting of commercial waste and / or household waste, generally still contains contaminants such as glass or metals after being roughly shredded. It is therefore known to carry out a separation after the coarse comminution and, if necessary, to comminute the substitute fuel further.

The object of the present invention is therefore to provide a device with which both the impurities can be separated from the substitute fuel and the substitute fuel can be generated with a different mean size of the substitute fuel particles.

The object is achieved by a device with the features of the independent claim. Advantageous developments of the device are in the dependent claims and specified in the description, with individual features of the advantageous developments being able to be combined with one another in a technically meaningful manner.

The object is achieved by a device for processing a material mixture consisting of substitute fuel and impurities, having a vertically oriented central feed, a separating device arranged below the central feed, a rotor mill, the rotor mill being arranged above the separating device and surrounding the central feed, and a flow device for generating an upwardly directed gas flow, wherein the material mixture can be introduced into the feed and sinks after the introduction into the feed to the separating device, wherein the contaminant in the separating device is at least partially separated as a contaminant fraction from the material mixture and that of the separated material mixture rises with the gas flow to the rotor mill, the rising material mixture being comminuted in the rotor mill. It is also provided that the rotor mill has a plurality of tools arranged vertically and offset from one another in the circumferential direction.

The material mixture can, for example, be introduced into the feed via a funnel or another feeding device, the feed being aligned vertically so that the material mixture introduced into the feed sinks in the feed. The feed is hollow on the inside so that the material mixture can sink undisturbed. For example, the feed can be formed by a tube (hollow cylinder).

A separating device is arranged below the central feed, which includes, for example, a rotatably drivable spreading plate. The separating device is designed in particular so that at least a large proportion of the Contaminants from the material mixture can be separated (sifted), wherein the separated contaminants can be removed from the device in a suitable manner.

A flow device is provided for separation / sifting, by means of which an upwardly rising gas flow can be generated at least in the area of the separation device, in particular in the area of the spreading plate of the separation device, and the rotor mill. For this purpose, the flow device has in particular at least one gas inlet preferably arranged in the lower region of the device and at least one outlet in the upper region of the rotor mill. For example, heated air can be used as the gas.

In particular, it is provided that the material mixture supplied through the central feed is thrown from the spreading plate into a space surrounding the spreading plate, in which the gas flow rises, with the rising gas flow only taking the substitute fuel with it, if possible, and a large part of the impurities in the spreading plate surrounding space drops. The substitute fuel that has been taken along is then also dried with the gas flow.

The substitute fuel carried along by the gas flow (and any impurities that have not been separated off) is fed with the gas flow to the rotor mill, which is arranged above the separating device (spreading plate). The substitute fuel is crushed in the rotor mill by impact, shear and impact forces. For this purpose, the rotor mill preferably has at least one rotationally driven tool which promotes the comminution of the substitute fuel.

The separating device (and in particular its spreading plate) and the tools of the rotor mill can preferably be driven together to rotate (rotationally) about a vertically aligned axis. Particularly preferably, the feed can also be driven to rotate at the same time. Here, the spreading plate can be non-rotatably connected to the element delimiting the feed (for example a pipe), the at least one tool of the rotor mill preferably being attached to an outside of the element forming the central feed inside. Thus, only one drive has to be provided for generating the rotary movement. The drive is arranged in particular in the lower region of the device and can, for example, generate a rotary movement with 500 to 1000, preferably with 700 to 900 revolutions / min.

The invention also provides that the rotor mill (and in particular also each stage of the rotor mill) has a plurality of, in particular more than 10, preferably more than 20 tools arranged vertically and offset from one another in the circumferential direction. This arrangement of the tools, offset both in the circumferential direction and in the vertical direction, results in a longer dwell time of the material mixture and thus more effective comminution of the material mixture, so that a higher degree of comminution can be achieved or the rotor mill can be realized with a lower height. The longer dwell time also improves the drying of the material mixture.

In this context, it is preferred if the rotor mill has a centrally arranged and rotationally driven hollow cylinder (which preferably also forms the central feed), on the outside of which the tools are attached, the tools each extending individually radially outward from the outside of the hollow cylinder . The tools are in particular elongated elements that differ from the Hollow cylinder extend outward. Thus, in particular, the entire area between the outside of the hollow cylinder and a radially spaced boundary of the rotor mill can be flowed through by the rising material mixture, with an interaction with the tools taking place in the entire area.

It can be provided that a group of tools and / or most tools include flat wing elements that extend radially outward. The wing elements are attached directly or indirectly to the outside of the hollow cylinder and are considerably longer in the radial direction (at least three times, preferably at least five times) as long as their width. In addition, the wing elements have a height which is less than their width, the wing elements being at least twice, preferably four times as wide as they are high. It has been found that a particularly efficient comminution of the material mixture is possible with such wing-like elements.

A further improvement in the comminution can be achieved in that the wing elements are positioned at an angle to a horizontal plane. The setting angle is preferably 3 ° to 45 °, particularly preferably 5 ° to 20 °, to the horizontal plane.

It can also be provided that at least one tool or a plurality of tools, preferably a major part of the tools, comprises a plate-shaped impact element which is arranged at a radial end of the tool, the plate-shaped impact element being particularly vertically aligned. With such a plate-shaped impact element, the comminution efficiency can be further increased.

In addition, it can be provided that at least one tool comprises a scraping element which is arranged radially on the outside of the tool and is in contact with a wall of the rotor mill or the stage of the rotor mill that delimits the grinding chamber on the outside, the wall being formed, for example, by a grid arrangement can that separates the grinding chamber from an annulus. With the scraping element, an accumulation of particles of the material mixture on the inside of the wall can be prevented or solved.

The plate-shaped impact element or the scraping element can, for example, be attached to a radial end of the previously described wing element of the tool.

It can also be provided that at least one tool is formed from a wire which is attached to the outside of the hollow cylinder. A wire is understood in particular to be such an element which extends outwardly from the hollow cylinder and whose width and height are approximately the same. The wire preferably has a circular cross-sectional configuration.

A plurality (in particular more than 8, preferably more than 16) of tools are preferably arranged in a lower area of the rotor mill or in a lower area of a stage of the rotor mill, each of which comprises a vane element, while in an upper area of the rotor mill or in one A plurality of tools comprising a wire are arranged in the upper region of a stage of the rotor mill.

For a particularly efficient comminution of the material mixture, it has been found that a group (more than 4) of tools can be arranged helically offset from one another (i.e. on a helical line), whereby several groups of tools can be arranged one behind the other in the circumferential direction.

In one embodiment it can be provided that the rotor mill is multi-stage, i.e. has at least and preferably exactly two or three stages, optionally four stages, with at least one separating device (for example a sieve) being arranged between the stages of the rotor mill Separation device not retained material mixture is further comminuted in the following stage, in particular particles of the mainly substitute fuel containing material mixture with a particle size specified by the separation device are retained in the previous stage, while particles of the material mixture with a smaller size can get into the following stage . In the following stage of the rotor mill, the material mixture is then comminuted further. The multi-stage rotor mill means that one device can provide substitute fuel with different mean particle sizes. The fraction of the material mixture withdrawn from the first stage can, for example, have an average particle size between 60 and 200 mm, while the fraction of the material mixture withdrawn from the second stage can have an average particle size of, for example, 10 to 60 mm.

In this context, it is preferred if at least one outlet is assigned to each stage of the rotor mill, via which the correspondingly comminuted material mixture, which mainly or at best exclusively contains substitute fuel, can be drawn off.

The second and, if appropriate, any further stage of the rotor mill are arranged in particular vertically above the first or preceding stage, the tools of each stage preferably being driven by a single common drive.

While it is possible in principle to implement the separating device using suitable separating methods, it is preferred if the separating device comprises at least one sieve in each case between the stages of the rotor mill. A simple separating device is provided with such a sieve.

In one embodiment it can be provided that an annular space is formed which surrounds the first stage of the rotor mill, in particular a grid arrangement functioning as a sieve being arranged between the outer annular space and the tools of the first stage of the rotor mill. The material mixture comminuted in the first stage of the rotor mill can thus pass through the grid arrangement into the annular space, from which the comminuted material mixture can be withdrawn through the at least one first outlet. If a plurality (more than two) stages are formed, each stage following the first stage up to the last stage can also be assigned its own annular space which is separated from the tools of the corresponding stage by a grid arrangement.

In this context, it can also be provided that at a radially outer end of some tools of the (first stages of the) rotor mill scraper elements, which can also be referred to as scraping elements, are formed with which particles of the retained on the grid arrangement or a radial wall of the rotor mill Material mixture can be detached from the grid arrangement so that they can be fed to a further comminution in the first or the corresponding stage.

In addition, it can be provided that the separating device is assigned a cleaning device between the stages of the rotor mill, with which the material mixture retained by the separating device can be released from the separating device. The dissolved material mixture can thus be fed to a further comminution in the preceding stage, for which purpose, for example, a pulsation of the gas flow is also possible. In this case, the cleaning device can also be rotatably driven together with the tools of the previous stage, so that a continuous release of the retained material mixture from the separating device is possible.

Figur 1:

eine Vorrichtung zum Aufbereiten eines aus Ersatzbrennstoff und Störstoff bestehenden Materialgemischs,

Figur 2:

eine Schnittdarstellung durch die Vorrichtung und

Figur 3:

eine Detailansicht der Vorrichtung.

The invention and the technical environment are explained below by way of example with reference to the figures. It show schematically

Figure 1:

a device for processing a material mixture consisting of substitute fuel and contaminants,

Figure 2:

a sectional view through the device and

Figure 3:

a detailed view of the device.

The device shown in the figures for processing a material mixture consisting of substitute fuel and impurities has a vertically oriented central feed 1 which is radially delimited by a hollow cylinder 12. A funnel is formed above the feed 1 through which the material mixture is fed into the feed 1.

A separating device 2, which comprises a spreading plate 14, is formed below the central feed 1. The spreading plate 14 is non-rotatably connected to the hollow cylinder 12, so that the spreading plate 14 and the hollow cylinder 12 can be driven to rotate together.

Tools in the form of wing elements 8a and wires 8b are arranged on the outside of the hollow cylinder 12, so that they can be driven to rotate together with the hollow cylinder 12 about the longitudinal axis of the hollow cylinder. The tools 8a, 8b form a rotor mill 3 arranged above the separating device 2.

The device also comprises a flow device 4 with an inlet 15, a first outlet 7.1 and a second outlet 7.2. The flow device 4 can be operated by blowing in a gaseous operating medium at the inlet 15 or by sucking off the gaseous operating medium at the outlets 7.1 and 7.2. The interior of the device is designed in such a way that the operating medium entering through the inlet 15 flows upwards past the radially outer edge of the spreading plate 14 into the rotor mill 3.

The rotor mill 3 has a first stage 5.1 to which the first outlet 7.1 is assigned. The rotor mill 3 also has a second stage 5.2, to which the second outlet 7.2 is assigned. The tools 8a and 8b of the first stage 5.1 are radially surrounded by a grid arrangement 10 which separates the tools from an annular space 9. In addition, a separating device 6 in the form of a sieve is formed between the first stage 5.1 and the second stage 5.2.

The first stage 5.1 and the second stage 5.2 of the rotor mill 3 each comprise a multiplicity of vane elements 8a which are attached in groups in a helical manner to the outside of the hollow cylinder 12 and which extend from the outside of the hollow cylinder extend radially outward. The wing elements 8a are aligned with an angle of attack to a horizontal plane. Plate-shaped impact elements 13 are attached to the outer ends of the wing elements 8a. On the other hand, scraping elements 11 are attached to some wing elements 8a, with which components of the material mixture retained by the grid arrangement 10 can be detached from the grid arrangement 10. In the upper area of the first stage 5.1, scratching elements can also be attached indirectly to the hollow cylinder 12 as a cleaning device, with which material retained by the separating device 6 can be detached. In the upper area, the first stage 5.1 and the second stage 5.2 each have wires 8b as tools, which are attached to the outside of the hollow cylinder 12.

During operation, a material mixture consisting of substitute fuel and impurities is introduced into the vertically oriented central feed 1, in which the material mixture sinks down to the separating device 2 comprising the spreading plate 14. As a result of the joint rotary movement of the spreading plate 14 and the hollow cylinder 12 delimiting the feed 1, the material mixture is accelerated radially outwards when it reaches the spreading plate 14 at the latest. The material mixture passing over the outer radial edge of the spreading plate 14 is sifted due to the rising gas flow, so that above all foreign matter in the space surrounding the spreading plate 14 sinks down, while the remaining material mixture, mainly containing substitute fuel, with the gas flow into the first stage 5.1 of the rotor mill 3 entry.

In the first stage 5.1, the material mixture is comminuted by interacting with the tools 8a and 8b as well as with each other. Due to the vertically and circumferentially offset arrangement of the tools 8a, 8b, effective comminution can take place, with comminuted Material can pass through the grid arrangement 10 into the annular space 9, this part of the material mixture being withdrawn from the first outlet 7.1.

The material mixture passing through the separating device 6 is further comminuted in the second stage 5.2, so that the material mixture exiting from the second outlet 7.2 has a smaller mean particle size than the material mixture exiting from the first outlet 7.1.

The device can therefore not only be used for particularly efficient comminution, but rather a material mixture with different particle sizes can also be provided.

List of reference symbols

1

Feed

2

Separator

3

Rotor mill

4th

Flow device

5.1

first stage

5.2

second step

6th

Separator

7.1

first outlet

7.2

second outlet

8a

Wing element

8b

wire

9

Annulus

10

Grid arrangement

11

Scraping element

12th

Hollow cylinder

13th

Impact element

14th

Spreading plate

15th

inlet

Claims (11)

Apparatus for processing a material mixture consisting of substitute fuel and impurities, having - a vertically aligned central feed (1), - a separating device (2) arranged below the central feed (1), - A rotor mill (3), the rotor mill (3) being arranged above the separating device (2) and surrounding the central feed (1), - a flow device (4) for generating an upwardly directed gas flow,
wherein the material mixture can be introduced into the feed (1) and, after being introduced into the feed (1), sinks to the separating device (4) The material mixture separated from the separated contaminants rises with the gas flow to the rotor mill (3), the rising material mixture being comminuted in the rotor mill (3), wherein
the rotor mill (3) has a plurality of tools (8a, 8b) arranged vertically and offset from one another in the circumferential direction. Device according to claim 1, wherein the rotor mill (3) has a centrally arranged and rotationally driven hollow cylinder (12), on the outside of which the tools (8a, 8b) are attached, the tools (8a, 8b) extending from the outside of the hollow cylinder (12) each extend radially outward. Apparatus according to claim 1 or 2, wherein the tools comprise flat wing elements (8a) which extend radially outward. Apparatus according to claim 3, wherein the wing elements (8a) are inclined at an angle to a horizontal plane. Device according to one of the preceding claims, wherein at least one tool (8a, 8b) comprises a plate-shaped impact element (13) which is arranged radially on the outside of the tool (8a, 8b) and is in particular aligned vertically. Device according to one of the preceding claims, wherein at least one tool comprises a scraping element (11) which is arranged radially on the outside of the tool (8a, 8b) and is in contact with a wall (10) delimiting the grinding chamber on the outside. Device according to one of the preceding claims, wherein at least one tool is formed from a wire (8b). Device according to one of the preceding claims, wherein at least one group of tools (8a, 8b) is arranged helically. Device according to one of the preceding claims, wherein the feed (1), the separating device (2) and the rotor mill (3) can be driven together to rotate about a vertically aligned axis. Device according to one of the preceding claims, wherein the separating device (2) comprises a rotatably drivable spreading plate (14). Apparatus according to Claim 10, the material mixture being thrown from the spreading plate (14) into a space surrounding the spreading plate (14) in which the gas flow rises.

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