EP0265422B1 - Process and device for mechanically removing the surface of lumped goods - Google Patents

Abstract

PCT No. PCT/DE85/00553 Sec. 371 Date Feb. 19, 1988 Sec. 102(e) Date Feb. 19, 1988 PCT Filed Dec. 21, 1985 PCT Pub. No. WO87/03826 PCT Pub. Date Jul. 2, 1987.A process and an apparatus for mechanically removing a sulphur containing layer from lumped lime, wherein the lumped lime is accelerated from a bottom member by a mechanical impulse and projected from the bottom member against a processing surface having profiles provided over partial sections thereof to remove the sulphur containing layer, when the lumped lime returns to the bottom member and the process is repeated along a conveying path for the lumped lime for a determined length of time, or for as long as it takes to achieve the desired removal of the sulphur containing layer.

Description

The invention relates to a method and a device for the mechanical surface treatment of piece goods, such as are known for example from FR-A-2.186.340. The burrs of bodies made of thermoplastic materials or rubber, which arise during production, are to be torn off or broken off. For this purpose, the parts are first frozen with a liquid cooling gas and then flung back and forth in the brittle state between a floor and a treatment surface arranged at a distance. Only burrs can be broken off and, for example, no depressions on the surface can be treated.

The surface of lumpy goods has to be treated mechanically in the most diverse areas of technology. In some cases, it is a matter of completely or partially removing a shell or skin. This skin or shell can be of the same material quality as the _" core" of the respective piece, but it can also be the other way around, to remove the surface made of a different material.

The peeling of fruit or the cleaning of potatoes may be mentioned in this context as an example.

Likewise, the term _" removal of surfaces of lumpy goods" also includes the removal of surfaces which as such do not form an independent component, but for example have a different chemical or mineral composition compared to the rest of the material (the core). The surface of lump lime made with sulfur-containing fuels is mentioned as an example of this field of application.

For the production of lime, high amounts of energy are necessary for the management of the pyro process. In principle, a wide variety of energy sources, such as coal, coke and / or natural gas or oil, come into question. In addition to its high calorific value, natural gas is characterized in particular by the fact that it is almost sulfur-free. Fuels such as coke or lignite products (lignite dust), on the other hand, have a significant sulfur content, which means that lime products from lignite firing, for example, are two to three times higher in sulfur than those from natural gas firing.

Further tests have shown that the sulfur content of the burnt lime product is extremely high, especially in the surface area, and decreases significantly with increasing layer depth.

Lump limes with an S0 ₃ content of less than 0.1% by weight, often less than 0.05% by weight, are required for use in the steelworks sector. Such concentrations cannot be achieved with solid (sulfur-containing) fuels without an appropriate (mechanical) aftertreatment. A reduction in the sulfur content of the fuel is technically possible, but too expensive.

Because of the concentration gradient across the grain cross-section described above, it is generally sufficient to remove only a relatively thin surface layer. The biggest problem is that the lump of lime is not in spherical or other symmetrical form, especially with a smooth surface, but in a wide variety of configurations, so that certain (especially past) surface areas are difficult to access.

A (unpublished) proposal has become known for achieving _" mechanical desulfurization" by treating the material in a drum screen which may be provided with internally acting abrasive components. However, such a device has considerable disadvantages. On the one hand, an autogenous grinding is caused to a large extent, which leads to an undesirable generation of fractured surfaces (the steel industry demands lime in a certain grain spectrum).

Furthermore, considerable amounts of solids have to be removed in order, for example, to free the grain zones, which cannot be reached directly through indentations or dents, slots or sack pores due to the increased adjacent areas, from the surface zones of increased sulfur content. In the case of particularly irregular goods, as is actually the rule in lime production, this can lead to the fact that up to 50% by weight or more must be removed.

On the other hand, the use of the sulfur-containing fuels mentioned should be made possible, among other things, for cost reasons.

Another (likewise unpublished) proposal provides for mechanical processing of the grain surfaces by means of sandblasting. In the case of a mass-produced product such as lime, in addition of a relatively small piece size (steel mill lime is usually in the size range between 10 and 60 mm), such a method cannot be implemented, and the uniform surface treatment is also difficult.

The invention has for its object to show a way to mechanically treat lumpy goods in such a way that a largely uniform material removal is achieved over the entire surface. So, regardless of the shape of the piece and in particular its geometrical surface design, a layer of the same thickness as possible should be removed over the surface, or in other words: a way should be shown, with as little material loss as possible, to see a uniform material removal over the entire surface of the piece , to reach. The invention is also intended to offer the possibility of being used in the large-scale area.

In particular, an application should also be easily and safely made possible in the case of bulk goods. In addition, there is a demand to list a proposed solution gene, which allows adaptation to the product to be treated with the same principle and is therefore adaptable to the respective application.

The focus here is on the surface treatment of lumpy lime.

The invention is based on the knowledge that, regardless of the design of the surface, a uniform removal can be achieved in that the piece goods to be treated in each case with a certain kinetic energy along an adjustable transport route and / or over a certain time interval between a floor and one of these at a distance assigned to the treatment surface, which is provided with profiles at least over partial sections, is flung back and forth.

The invention accordingly proposes a method for the mechanical surface treatment of piece goods, in which the material, when subjected to a mechanical impulse, is flung back and forth between a floor and a treatment surface arranged at a distance therefrom, the material being moved along the transport path and / or during a specific time interval between the floor and the treatment surface provided with profiling, at least over partial sections, until a desired surface removal is achieved.

Accordingly, a device is proposed with at least one transport floor for the goods and a treatment area assigned to them at a distance, and a device for exerting a mechanical impulse on the goods to be treated, in which the treatment area is provided with profiles at least over partial sections.

The pulse device can be provided in different ways. In a first simple embodiment, a pulsating movable plunger is guided against the floor in a certain cycle sequence, which thus exerts an impulse on the material carried over it. An advantageous embodiment of the invention provides for a forced agitator to be arranged on the floor and / or the treatment surface. However, the device can also be arranged in such a way that it acts on it via corresponding intermediate organs.

A further embodiment according to the invention provides for the floor and the treatment surface to be connected to one another via rigid connecting elements, so that a type of treatment room is created and the forced agitator is fastened to one of the connecting elements. The forced agitator can be a vibrator, preferably an electric vibrator.

In a particularly advantageous embodiment, the invention provides that the forced agitator is formed by an unbalance device which is seated on a rotatably driven shaft. A circular or involute movement path for the floor, the treatment area and the material to be treated can be achieved in this way. At regular or irregular intervals (depending, for example, on the design of the unbalance disc, the speed of the drive element and the design of the floor and treatment area), an impulse is exerted on the piece goods lying on the floor, which is then accelerated in the direction of the treatment area and hits it before it falls back onto the floor, usually at a different angle.

According to the invention, the material is guided against a treatment surface provided with profilings at least over partial sections. The surface design of the treatment area plays an important role in terms of the quality and quantity of the surface removal.

The profiles can have, for example, a cone, pin, ball, hemisphere, quarter ball, wave, sawtooth or pyramid shape. The corresponding surface can, however, also be designed like a brush, for example. The invention further provides for forming individual sections of the treatment area with different profiles. Such an arrangement should be chosen depending on the goods to be treated.

The _" surface tools", in particular the projecting sections, mean that - as soon as the material is thrown against them - not only the surfaces are rubbed off or brushed off, but in particular also recessed surface parts can be removed if, for example, a pyramid-like projection in the area of one Indentation on the surface.

Optimization in the sense of a uniform surface removal is achieved in particular if the piece to be treated is guided along the transport path and / or during a certain time interval from the floor against the treatment area in as different directions as possible and where appropriate strikes different sections of the treatment area.

In a particularly preferred embodiment of the invention, this aim can be achieved in that the material is guided over a deformable floor and / or against a deformable treatment surface, the deformability preferably being achieved by an elastic material of the floor and / or the treatment surface.

The general cargo is then not only flung back and forth between the floor and the treatment surface due to its possibly irregular surface and / or inclination of the treatment line consisting of the floor and the treatment surface, but this effect is further enhanced by the elastic surfaces, the respective geometric alignment is further influenced by the forced agitator. Similar to a trampoline, the parts are then caught and flung away, reinforced by the additional, from the forced agitator brought impulse. Counter vibrations are set up with variable frequency distribution. The process control is preferably selected such that the acceleration of good when the treatment area is reached is a multiple of the acceleration due to gravity, preferably three to six times.

An optimization of the surface removal can be achieved in that the floor is also designed with profiling in an analogous manner to the treatment area and thus also acts as an _" active area".

In terms of a uniform and effective Oberflächenabtrages with minimum material loss, it has been found to be advantageous _"in Gteichftuss" to drive. The direction of movement of the goods is the same as the direction of the applied impulse. This creates a kind of role effect.

With regard to the arrangement of the floor and treatment surface, it is proposed in an advantageous embodiment of the invention to choose the distance between the two depending on the size of the piece goods being carried out, a distance of less than twice the largest piece goods diameter having proven to be particularly advantageous. Within this range, a distance that is 20 to 40% larger than the largest diameter is preferred. The effect of the corresponding treatment areas is particularly high. With an adjustable pulse frequency and amplitude, a large number of touch contacts can be achieved over relatively short treatment distances and / or time intervals, as a result of which a corresponding surface layer is not only removed more quickly, but also - as described in detail above - more uniformly.

The invention thus proposes a completely new type of mechanical surface removal, and in particular a completely new kinetics of the material to be treated. In this way, together with special geometrical designs of the treatment surface (s), surface areas can also be removed that were previously not accessible with known methods, in particular recessed surface parts. In addition, the forced agitators described require relatively little electrical energy when generating strong mechanical pulses and high efficiency. Furthermore, for example, by changing the configuration of the floor and / or treatment area, the pulse strength and direction, the distance and the orientation of the floor and treatment area, their inclination, movement to one another and / or material properties, changes in the sense of a different good load are easily possible , whereby one and the same device can be adapted to different piece goods to be treated.

A further optimization of the method according to the invention or of the device according to the invention can be optimized in particular taking into account the given rule of determining the distance between floor and treatment surface in a certain way by dividing the material flow into different grain fractions and feeding them to a separate device, According to an advantageous embodiment of the invention, the corresponding system is designed in such a way that a separation according to different grain sizes is carried out by sieving over a common feed area, and the material flow with the finer material that falls through downwards is fed to a device that but is arranged essentially parallel to the first device for the coarser fractions. The system is particularly compact. A forced agitator can act on both devices or their parts together, for example, by the treatment lines being connected to one another via a fixed mechanical linkage and seated on a common spring bearing.

The individual device or the complete system is preferably encapsulated in a dust-tight and sound-absorbing manner and, as a further advantageous embodiment of the invention provides, is kept dust-free by connecting a suction device.

The device according to the invention, if appropriate in combination with other devices, is particularly suitable for the mechanical desulfurization of lump lime (steelwork lime), since, among other things, the advantages according to the invention are particularly clear due to the irregular surface properties of lime lime. The mode of operation of the method according to the invention can also be improved for such an application in that a moisture mist (water mist) is sprayed onto the material in the application area for the material, a superficial hydration occurring which makes the material somewhat softer and therefore less abrasion-free. Of course, this advantage applies to the processing of all hydratable substances.

It has been found that the energy with which the particles strike the treatment surface (s) is decisive for the surface removal. It has been shown that large grains experience a higher surface erosion than small grains with the same throughput time. The invention therefore proposes, in an advantageous embodiment, to subdivide the material flow to be treated into partial flows of different grain fractions, as has already been explained above, but also to send different treatment lines, for example in terms of inclination, according to the desired surface removal, so that - independently of the grain size - an approximately equally thick layer is always removed.

Due to the completely new treatment, the mechanically desulphurized material also differs in its outer habit from the material sent through a drum screen. Ent Accordingly, the invention also comprises a lumpy good, in particular lump lime, which is produced using the method according to the invention and / or in the device according to the invention. Such a product has a particularly uniform surface.

The mechanical desulfurization according to the invention is not only particularly effective, but the method and the device are also particularly easy to handle and enable the goods to be processed quickly and effectively.

This applies not only to the lump lime mentioned above, but also to the other areas of application mentioned at the beginning. Further features of the invention result from the remaining claims and the further description documents.

The invention is described below with reference to an embodiment. This shows a system for mechanical surface treatment of lump lime for use in the steelworks area, where only lime qualities with a particularly low sulfur content can be used. The system therefore serves for the mechanical desulfurization of the lime in the surface area.

• Figur 1a: Einen Längsschnitt durch eine erfindungsgemässe Anlage zur mechanischen Oberflächenbehandlung von Stückkalk.
• Figur 1 b: Eine vergrösserte Darstellung des Aufgabebereiches der Anlage gemäss Figur 1 a.
• Figur 2: Einen Querschnitt durch die Anlage nach Figur 1.
• Figur3: Einevergrösserte Schnittdarstellung der Behandlungsfläche der Anlage gemäss den Figuren 1, 2 entgegen der Transportrichtung gesehen.
• Figur4: Eine vergrösserte Schnittdarstehung der Behandlungsfläche senkrecht zur Transportrichtung.
• Figur 5: Eine Aufsicht auf den Boden einer Behandlungslinie der Anlage gemäss Figur 1 a.
• Figur 6: Ein Fliessbild zur Darstellung der einzelnen Verfahrensschritte bei der Behandlung von Stückkalk nach einer bevorzugten Ausführungsform.

The drawing shows schematically in

• Figure 1a: A longitudinal section through an inventive system for the mechanical surface treatment of lump lime.
• Figure 1 b: An enlarged view of the task area of the system according to Figure 1 a.
• Figure 2: A cross section through the system of Figure 1.
• Figure 3: An enlarged sectional view of the treatment area of the system according to Figures 1, 2 seen against the direction of transport.
• Figure 4: An enlarged sectional view of the treatment area perpendicular to the direction of transport.
• Figure 5: A top view of the bottom of a treatment line of the system according to Figure 1 a.
• Figure 6: A flow chart to illustrate the individual process steps in the treatment of lump lime according to a preferred embodiment.

The system according to FIGS. 1 to 5 consists of two treatment lines 10, 12 arranged at a distance from one another. Each of the treatment lines has a bottom 14 or 16. So-called treatment areas 18, 20 are arranged above each floor and parallel to it.

The floors 14, 16 and the treatment surfaces 18, 20 have the shape of elongated rectangles when viewed from above and are rigidly connected to one another and to one another at their opposite longitudinal edges by side walls 22, 24.

Each floor 14, 16 consists of a circumferential metal frame 26, the longitudinal sides of which are connected to one another at a distance from one another via cross struts 26a. A rubber blanket 28 is stretched or fastened on the metal frame 26 or the cross struts 26a, for example via a tensioning device (not shown) in the frame area or suitable screw connections. The rubber blanket has, over its surface in the longitudinal direction and perpendicular to it, spaced closed strips 28a which enclose rectangular areas 28b. The areas 28b are provided with a plurality of through openings 28c.

The rubber blanket can consist of a hard rubber material, for example.

The treatment surfaces 18, 20 each consist of a metal sheet, preferably a steel sheet. The steel sheet has a plurality of openings 30 arranged side by side and one behind the other, which are designed as sections which are expressed in the direction of the associated floor 14 or 16 and are only open in the direction of transport of the material to be treated (arrow direction A). The openings 30 are therefore not produced by simply punching them out, but by pressing them out, similar to a grater. The passage openings 30 are preferably small and closely spaced from one another. FIGS. 3 and 4 show a front view and a side view of the treatment surfaces 18, 20, wherein in particular in FIG. 4 a longitudinal section shows a sawtooth shape of the individual sections 32 which are open and are open in the direction of transport (arrow A).

In the exemplary embodiment shown, the treatment areas 18, 20 are designed over their entire area in the manner described. However, in the sense of the invention it is also possible to design only partial areas in this way, while other areas are either unprofiled or else have projections and recesses of other configurations, for example a cuboid shape, pyramid shape, hemisphere or quarter-sphere shape. Likewise, the surface of the treatment surface 18, 20 facing the respective floor 14 or 16 can also be designed with pins projecting downwards, similar to a brush. It is also particularly advantageous if the projections and recesses have a different overall height (depth), that is to say project more or less downwards in the direction of the associated floor 14, 16.

Shoulders 34a, b projecting vertically at the ends are welded to the side walls 22, 24 and are parallel and at a distance from an associated foundation 36a, b. A pair of compression springs 38a, b is arranged between each shoulder 34a, b and the associated foundation 36a, b, the associated compression springs resting against the shoulder 34a, b or the foundation 36a, b under tension. To mechanically support the shoulders 34a, b, associated angles 40a, b are welded to the side walls 22, 24.

As can be seen in particular from FIG. 2, the distance between floor 16 and the associated treatment surface 20 is somewhat less than the distance stood between floor 14 and treatment surface 18. The corresponding distances are dependent on the goods to be treated, as explained above.

The distance between the treatment surface 20 of the treatment line 12 and the floor 14 of the treatment line 10 arranged above it is a multiple of the last-mentioned distance between the components 14, 18.

The floors 14, 16 can be designed in the same way as the treatment surfaces 18, 20, in particular profiles can also be provided on the floors 14, 16.

FIG. 1a shows that the treatment lines 10, 12 or the associated components are provided with a slope, specifically from a feed area 44 to a removal area 46. The feed area 44 has a device 48 which essentially has the shape of a shaft and is shown in an enlarged (schematic) representation in FIG. 1b.

At its upper end, the device has a receiving funnel 50, to which two slide sections 52, 54, which run at an angle a to one another with a slope toward the floor 14, are connected, which pass over steps 56, 58 into lower slide sections 60, 62. Starting from steps 56 and 58, the slide sections 60, 62 run with a shape that widens trapezoidally when viewed from above. Correspondingly, vertical slats 64 are arranged on the slide sections 60, 62, widening at a distance from one another, and their distance from one another in the area of step 58 is smaller than at the opposite end. The bottom of the slide sections 60, 62 is designed as a sieve bottom 66. The front end of the sieve plate 66 in the transport direction A merges into the initial region of the plate 14 and is arranged somewhat above it.

Below the sieve bottom 66, the device 48 continues with a free-fall section 68, which, as shown in FIG. 1b, is likewise divided into vertically extending chambers 72 with vertical slats 70.

The bottom of the free fall section 68 is in turn designed as a sieve plate 74, with a smaller mesh size than the sieve plate 66. The front edge of the sieve plate 74 in the transport direction A is arranged somewhat above the plate 16, which adjoins the sieve plate 74 directly. A funnel-shaped discharge 76 is arranged below the sieve bottom 74.

Below the treatment line 12, two further collecting funnels 78, 80 are arranged one behind the other in the transport direction A, which are directed together with the discharge 76 onto a common (not shown) conveyor belt.

The treatment line 10 is closed at the top with two cover plates 82, 84 arranged in a vault-like manner in the transport direction A, each of which has a suction device 86 on the top side.

At the removal area 46, two downwardly angled channels 88, 90 connect to the treatment lines 10 and 12, respectively, which are directed towards a conveyor belt (not shown).

Approximately in the middle of the treatment lines 10, 12 (seen in the transport direction A), a shaft 92 projects through the side walls 22, 24, in which it is rotatably mounted. On the outside there is an imbalance disc with variable mass on the shaft ends. Each imbalance disk 94 is rigidly connected to the shaft 92. On the free end assigned to the side wall 24, a pulley 96 also sits on the shaft 92 and serves to receive a belt (not shown) which is guided at a distance from the pulley 96 around a further pulley which is seated on a motor shaft. The belt drive thus serves to rotate the shaft 92.

Instead of the unbalance drive described, an eccentric drive can also be provided, for example. The invention also provides for the possibility of placing a vibration device directly on one or both side walls 22, 24 and / or the floors 14, 16 or treatment surfaces 18, 20.

FIG. 6 shows an example of a flow diagram for the mechanical treatment of quicklime with a plant according to the invention.

In the introduction it was pointed out that the mechanical treatment of steelwork lime is about achieving a product with the lowest possible sulfur content. The system according to the invention is used for this purpose, with the aid of which the surface area of the lump lime, which is particularly loaded with a high sulfur concentration, is to be removed.

As FIG. 6 shows, the material flow first passes through a sieve, on which the grain fraction larger than 50 mm is separated off. It has been found that the proportion of the sulfur-laden surface to the total volume of these pieces is relatively small, so that when viewed in terms of the mass as a whole the sulfur content is within the permissible range, so that this material is not mechanically desulfurized in the exemplary embodiment shown needs.

The remaining material flow (less than 50 mm) passes through the desulfurization plant according to the invention.

For this purpose, the material reaches the chutes 52, 54 via the receiving funnel 50 and divides into two equally large streams. Due to the gradient of the slide sections (chutes) 52, 54, the material slides further down. It reaches the slide sections 60, 62 where each material flow is further divided into five partial flows by the lamellae 64. Because of the geometrical arrangement of the lamellae 64, the partial flows are guided such that they are evenly distributed over the entire width of the system at the transition to the floor 14.

A screening also takes place along the paths 60, 62, the material being less than 30 mm down through the sieve plate 66 and the free fall section 68 to the sieve plate 74, where a further sieving takes place and only the material smaller than 10 mm is allowed to pass. The latter is fed to a screen via the discharge 76 without mechanical surface treatment, which will be described in more detail below.

The two grain fractions 30 to 50 mm and 10 to 30 mm then reach the associated bottoms 14 and 16 from the screen surfaces 66, 74 either due to their inclinations and / or due to connected vibrating devices. With mechanical connection to the side walls 22, 24, the said one can Device 48 can be set in motion by the unbalance drive 92, 94.

As soon as the individual piece of lime has reached the bottom 14 or 16, the mechanical surface removal begins.

Due to the rotating unbalance 94 (here at a speed of 750 rpm), a short-wave oscillating movement is transmitted via the rigid side walls 22, 24, the height of the corresponding oscillation amplitude being adjustable, inter alia, by the configuration and arrangement of the unbalanced mass 94. In the illustrated embodiment, an oscillation amplitude of 20 mm is selected. The forces transmitted by the mass 94 are absorbed by the compression spring pairs 38a, b. The device as a whole is moved on an approximately circular path of movement, with a direction of movement as indicated by the arrow B.

It has proven to be particularly advantageous to operate the system _" in co-flow", that is, to allow the unbalanced mass 94 to rotate in the transport direction of the goods (arrow direction A).

It is readily apparent that the material lying loosely on the floor 14 or 16 is initially carried lying down on the respective floor 14 or 16 during a first upward movement of the unbalanced mass 94.

Subsequently (during the downward movement (return) of the unbalanced mass 94), the device parts themselves are guided downwards again due to the rigid connection between them. However, the pieces previously lying on the shelves 14, 16 experienced such acceleration during the upward movement that they were detached from the associated shelf 14 or 16 and flung against the corresponding treatment surface 18, 20, from where they hit the shelf 14 or 16 bounce back. Depending on the mass of the individual parts, their surface design, their impact and rebound angle with respect to the treatment surface 18 or 20, as well as the vibration amplitude set on the drive side, each piece of limestone is quickly moved between the floors 14 or 16 and the associated treatment surfaces 18 or 20. and hurled here. It is important that, based on the specified parameters, each piece of lime is moved back and forth between the floor and the treatment surface with a slightly different orientation, so that always different surface sections come into contact with the abrasion elements. This effect is reinforced by the selection of an elastic base 14 or 16. It is readily understandable that the elastic floor as a whole also experiences deformations when the device is vibrated, so that the distance between the floor and the associated treatment surface is additionally dependent on the respective deformation of the elastic floor 14 or 16. As a result, however, the individual pieces of lime meet again at differently inclined surfaces, as a result of which they are returned at a new angle.

Due to the constant spinning of the solid particles against the treatment surface 18 or 20, but also when they hit the corresponding floor 14 or 16, surface abrasion takes place, so that the high-sulfur-containing outer skin is gradually removed. The scraped-off fine material can be discharged downwards through the openings in the bottom 14 or 16. The fine material from the treatment line 10 will first fall through the space between the treatment lines 10, 12 and then be fed to the collecting funnels 78, 80 via the openings in the treatment surface 20 and the openings of the associated base 16.

Due to the inclination of the device as a whole or in particular of the trays 14, 16, but also reinforced by the direction of rotation of the unbalance drive, the individual pieces of material between the tray 14, 16 and the associated treatment surface 18, 20 are _" dancing" from the feed area 44 to the removal area 46, where there is a large number of surface contacts between material and treatment surface 18, 20 or floor 14, 16 due to the high pulse rate.

The choice of the length of the system or the set pulse rate as well as the other aforementioned parameters are set depending on the piece goods to be treated in each case. Likewise, in individual cases, the geometric design of the tools on the underside of the treatment surfaces 18, 20 or — as an alternative embodiment provides — also be set on the corresponding floors 14, 16. In the exemplary embodiment, the treatment surfaces 18, 20 have the same design over the entire conveying path, in a manner similar to a grater with projections which are pressed downwards and open in the direction of arrow A. The material abrasion thus takes place by streaking the individual grain along the expressed surface section, whereby a _" softer" material abrasion is achieved than if the individual parts hit the openings 30 of the expressed ab cuts 32 would be thrown, as would be possible by reversing the direction of rotation of the unbalanced mass 94.

It has been shown that a treatment, as shown in the exemplary embodiment, achieves a very smooth surface of the individual pieces of lime, which indicates a particularly gentle treatment.

In particular, the surface areas of troughs on the surface of a piece of lime are rubbed in almost the same way and at the same depth, since, due to the material guide according to the invention, abrasion knobs, such as the expressed sections 32, can also get into such troughs.

The rubbed-off fine material is drawn off via the collecting funnels 78, 80 and fed to the same sieve into which the fine flow drawn off from the feed area also reaches.

The mechanically desulfurized coarse grain (grain fraction 10 to 50 mm) passes through the channels 88, 90 from the plant, for example, into a silo (not shown). A partial flow of the grain fraction 10 to 50 mm also flows into this, which is drawn off at the end of a roll crusher system into which the initially branched oversize (larger than 50 mm) is fed.

The fine material (less than 10 mm) that is withdrawn from the desulfurization plant, together with the fine material that arises at the end of the roll crusher, goes into a screening plant, where it is divided into further grain fractions, for example 3 to 10 mm and smaller 3 mm, in order to then be further bunkered or filled elsewhere.

An example illustrates the mode of operation of a system according to the invention, as shown in the drawing.

A burnt lime with an S0 ₃ content of 0.13 weight percent in the grain fraction 10 to 50 mm is available as the starting material. The material was then fed into the system according to the drawing and passed through it in a co-flow. Approximately 15 percent by weight of material was removed along the treatment section, that is, 15 percent by weight of the feed stream was withdrawn via the removal devices 76.78.80. The remaining 85 percent by weight in the 10 to 50 mm grain range then had an S0 ₃ content of only 0.05 percent by weight, which corresponds to a reduction of about 60 percent. A drastic reduction in the S0 ₃ content could be achieved with very little material loss.

Numerous further developments and alternatives are possible within the scope of the invention. Instead of guiding the material flow along a treatment section, as explained above with reference to the exemplary embodiment, the material can also be placed on a defined (horizontal) surface and hurled against a treatment surface arranged above it, among other things via the setting of a specific time interval and the applied pulse the intensity of surface abrasion can be controlled.

If a particularly gentle surface removal is desired, it can be sufficient to design the treatment area without profiling or only roughened or to push the sheet outwards (away from the floor), so that only _" negative" discontinuities are formed in the treatment area for the material guided against it.

Claims (31)

1. Process for mechanical surface treatment of lumped goods wherein the goods, starting from a bottom, are accelerated by a mechanical impulse and projected against a processing surface arranged in a distance thereto, returning thence to the bottom, characterised in that the goods are treated along a conveying path and/or for a pre-determined period of time between the bottom (14, 16) and the processing surface (18, 20) provided at least over partial sections with profiles (32) until a desired surface removal is achieved.

2. Process according to claim 1, characterised in that the goods resting on the conveying bottom (14, 16) are exposed to mechanical impulses applied in rapid succession and the impulses being preferably applied to the goods via a vibration, impact or oscillating arrangement, bearing on the bottom (14, 16) and/or the processing surface (18,20).

3. Process according to claim 1 or 2, characterised in that the acceleration applied to the goods by an impulse is so high that on reaching the processing surface (18, 20) it amounts to many times the acceleration due to gravity.

4. Process according to claim 3, characterised in that the goods acceleration is 3 to 6 times the acceleration due to gravity, preferably 4 to 5 times.

5. Process according to one of claims 1 to 4, characterised in that the goods are conveyed along the conveying path and/or for a pre-determined period of time in their movements between bottom (14, 16) and processing surface (18, 20) at varying angles to the bottom (14,16) or the processing surface (18, 20).

6. Process according to claim 5, characterised in that the goods are conveyed over a deformable, preferably an elastic bottom (14,16) against a deformable, preferably elastic processing surface (18,20).

7. Process according to one of claims 1 to 6, characterised in that the goods are moved along a gradient.

8. Process according to one of claims 1 to 7, characterised in that the goods are conveyed in a rotating manner between the bottom (14,16) and the processing surface (18, 20).

9. Process according to one of claims 1 to 8, characterised in that the source material is divided into streams of varying granular fraction and these are processed separately from one another.

10. Process according to one of claims 1 to 9 for the processing of lumped line.

11. Process according to claim 10, characterised in that the source material, before being introduced into the space between bottom (14, 16) and processing surface (18, 20), is brought into contact with a substance which reacts with the surface.

12. Device for mechanical surface treatment of lumped goods having at least one conveying bottom for the goods and a processing surface located at a distance therefrom, and an arrangement for applying a mechanical impulse to the goods to be processed, characterised in that the processing surface (18, 20) is provided at least over partial sections with profiles.

13. Device according to claim 12, characterised in that the bottom (14, 16) and/or the processing surface (18, 20) is (are) constructed deformable, preferably elastic.

14. Device according to claim 12 or 13, characterised in that the arrangement for applying the mechanical impulse to the goods is arranged on the bottom (14, 16) and/or the corresponding processing surface (18, 20) and/or elements (22, 24) connecting the bottom (14, 16) with the corresponding processing surface (18, 20) or acts on these via appropriate intermediate organs.

15. Device according to one of claims 12 to 14, characterised in that the bottom (14, 16) and/or the processing surface (18, 20) are arranged spring mounted directly or indirectly, preferably via springs or silentblock type connection and movable by a constraining agitator (92, 94).

16. Device according to claim 15, characterised in that the constrained agitator is a vibrator, preferably an electrical vibrator.

17. Device according to claim 15, characterised in that the constrained agitator (92, 94) is created by an unbalanced arrangement (94), mounted on and fixed to a shaft (92) driven rotatable by a motor.

18. Device according to one of claims 12 to 17, characterised in that the bottom (14, 16) and/or the processing surface (18, 20) are movable along a rotating or involute conveying track.

19. Device according to one of claims 12 to 18, characterised in that the bottom (14, 16) and the processing surface (18, 20) are movable asynchronously with one another.

20. Device according to one of claims 12 to 19, characterised in that the angle of inclination to the horizontal line of the bottom (14, 16) and/or the processing surface (18, 20) may be adjusted.

21. Device according to one of cia,ims 12 to 20, characterised in that the bottom (14, 16) is provided at least over partial sections with profiles (32).

22. Device according to claim 21, characterised in that the profiles consist of projections and recesses which are spherical, hemispherical, quarter-spherical, cubic, undulated, a saw tooth and/ or pyramidic and/or take the form of a brush.

23. Device according to claim 21 or 22, characterised in that the processing surface (18, 20) is divided into zones of different profiles.

24. Device according to one of claims 12 to 23, characterised in that the distance between bottom (14, 16) and corresponding processing surface (18,20) is less than twice and more than the maximum diameter of the lumped goods charged.

25. Device according to one of claims 12 to 24, characterised in that the bottom (14, 16) and/or the processing surface (18, 20) consist(s) of a rubber blanket (28), preferably a hard rubber blanket.

26. Device according to one of claims 12 to 25, characterised in that on the infeed side end, an arrangement (48) is arranged to divide the goods over the entire width of the bottom (14, 16).

27. Device according to one of claims 12 to 26, characterised in that at least one receiving arrangement (78, 80) is provided beneath the bottom (14, 16).

28. Device according to one of claims 12 to 27, characterised by a sound- and dustproof casing (82,84) and at least one suction arrangement (86) connected thereto.

29. Unit with at least two devices according to one of claims 12 to 28 for mechanical processing lumped goods of varying granular fractions.

30. Unit according to claim 29, characterised in that on the infeed side a sieve-arrangement (66, 76) is provided for separating the streams of material.

31. Lumped lime, preferably from a combustion unit driven by fuels containing sulphur, which has been processed by a process according to one of claims 1 to 11 and/or by a device or unit according to one of claims 12 to 30.

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