WO2006032421A1

WO2006032421A1 - Method for grinding cement clinker

Info

Publication number: WO2006032421A1
Application number: PCT/EP2005/010036
Authority: WO
Inventors: Roland Schüssler
Original assignee: Pulsar Gmbh Micronizing Systems
Priority date: 2004-09-22
Filing date: 2005-09-17
Publication date: 2006-03-30
Also published as: DE102004045894A1

Abstract

The invention relates to a method for grinding a cement clinker for cement-like building materials, wherein said cement clinker is produced from products obtainable by cold mineralisation of crushed waste products with additives for accelerating an exothermic oxydation and separation process. The inventive method consists in collecting a predetermined amount of cement clinker in the form of particles (2) in a tube (8, 8'), wherein said particles (2) form a plug (12) in the tube (8, 8'), in exposing the plug (12) to pressure impulse action whose intensity and duration are predefined in such a way that said plug is projected against an impact plate (6) disposes downstream of the tube (8, 8') by means of an output thereof, where at least one passage through which the particles ground by the impact against the impact plate (6) are removed is associated with said impact plate.

Description

Process for crushing cement clinker

The invention relates to a method for crushing cement clinker for the production of cementitious building materials.

From DE 100 45 172 Al a device for comminuting particles is known.

This device has at least one tube for collecting a predetermined amount of particles, the particles forming a plug in the tube. Furthermore, the device has at least one pressure pulse unit for generating pressure pulses, which is fired by acting on the plug with a pressure pulse through an outlet opening of the tube against a pipe downstream and breakthrough having baffle plate. Furthermore, the device has a collecting chamber adjoining the baffle plate, in which the particles crushed by the recoil on the baffle plate and passing through the apertures are collected.

The principle of this device is therefore to shoot these plugs against a baffle plate with openings for comminuting particles stored in the form of a plug in a tube.

The shear forces exerted on the particles by the impact lead to a comminution of the particles, with the particles typically being obtained from original particle sizes of 10 mm to particles with sizes of one or a few μm. As a result of the overpressure generated at the front of the baffle plate by the pressure pulse unit, the particles with small grain sizes and therefore a small weight are transported through the openings and reach the collecting chamber. In contrast, the heavier particles do not penetrate the breakthroughs and are preferably returned to the tube to form a new plug.

By a suitable choice of the diameter of the tube, the size and shape of the openings of the baffle plate and / or the size of the collecting chamber, the particle sizes and particle size distributions of the comminuted particles collected in the collecting space can be predetermined.

The baffle plate can be replaced if necessary. Thus, the particle size distribution of the comminuted particles collected in the collecting chamber can be varied by a change of different baffle plates with different breakthroughs.

Furthermore, the volume of the collecting chamber can be adjusted so that the grain size distribution of the shredded particles collected in the collecting chamber can also be varied.

A significant advantage of the device is that the sizes of the openings in the baffle plate are dimensioned so that it exerts a Sichterfunkti¬ on. This means that the crushed particles transported through the openings remain in the collecting chamber and are not transported through the openings back to the tube.

Due to the special design of the baffle plate and the collecting chamber arranged behind it, the comminuted particles having the desired particle sizes are collected in the collecting chamber with a high degree of efficiency and separated from heavier particles. Here, in the collecting chamber, at least one Entnahmeöffiiung provided over which the shredded Par¬ particles can be removed from the collecting chamber.

Another advantage of this device is that it has almost no moving parts, and that the only weary part is formed by the baffle plate, which is easily replaceable. Therefore, the device has a compact, robust and easy to maintain construction, which causes only low investment and maintenance costs. In addition, the comminution of the particles can be carried out with a low energy requirement, so that the operating costs of the device according to the invention are correspondingly low. Since the device has almost no moving parts and also preferably has a closed structure, this represents no danger to the operating personnel and is therefore harmless with regard to the provisions of occupational safety.

The device is particularly suitable for the comminution of hard materials with Mohs degrees of hardness in the range of 7 to 10. In particular, nitrides such as, for example, TiN, ZrN, HfN, TaN and BN _{3 can be} comminuted with the device according to the invention. Likewise carbides such as TiC, ZrC, HfC, TaC, WC, W ₂ C and Ta _0-8 Hf _0-2 C can be comminuted.

The invention has for its object to expand the scope of such a device.

To solve this problem, the features of claim 1 are provided. Advantageous embodiments and expedient developments of the invention are described in the subclaims.

The inventive method for crushing cement clinker used for the production of cementitious building materials, wherein the cement clinker by cold mineralization of crushed waste with the addition of additives to accelerate exothermic oxidation processes and separation processes is won. In a first method step, a predetermined amount of cement clinker is collected in the form of particles in at least one tube, the particles forming a plug in the tube.

In a subsequent method step, the plug is subjected to a pressure pulse of predetermined strength and length, so that it is fired via an outlet opening of the tube against a baffle plate arranged downstream of the tube, to which at least one breakthrough is assigned, whereby the force generated by the recoil Particles crushed on the baffle plate are passed through the aperture.

With the method according to the invention, a particularly efficient, cost-effective production of cementitious building materials is made possible.

The process is extremely environmentally friendly, since the cement clinker to be crushed from waste materials, d. H. is obtained from garbage.

The recovery of useful, in particular ceramic materials from zerklei¬ nertem waste by cold mineralization is known as ecocycling and described, for example, in the company publication of the company ecocycle technology gmbh, Luxembourg, 2003.

Accordingly, the Ecocycle method is to supply additives to shredded waste in order to generate a reactive mass in which separation and exothermic oxidation processes take place. In this cold mineralization process, a greatly accelerated through mineralization of the waste is obtained, at the end of the reaction process environmentally compatible ceramic granules are obtained which have crystalline structures in which heavy metals or other pollutants contained in the waste can be eingela¬ siege. The grand idea of the invention is not to discharge completely from the cold mineralization process by mineralized intermediates in order to obtain from these cement clinker which is used for the production of cementitious building materials according to the method defined in claim 1 and in the claims. 4 defined developments or embodiments zerklei¬ nert is.

A significant advantage of the comminution method according to the invention over, for example, crushing processes carried out with ball mills is that unwanted reagglomeration of the comminuted particles is avoided.

In particular, it is advantageous in the method according to the invention that in the comminution process by relaxing the compressed air of the compressed air pulse, a drying effect is achieved, i. The particles are deprived of moisture during the comminution process. This is therefore particularly advantageous, since the cement clinker is hygroscopic and moisture can be removed from it by the Zerklei¬ nerungsprozess without additional process steps.

The cement clinker comminuted by the method according to the invention is preferably mixed with a sand-shaped filler and a fibrous reinforcement to produce a concrete. Like the cement clinker, the filler and the reinforcement are obtained from intermediates of the ecocycling process, ie. H. these substances are extracted by discharging from the cold mineralization process of the additive enriched waste.

The concrete mass produced in this way can be extruded or shaped to any profiles or the like. Furthermore, it is advantageous that the concrete produced in this way has very good mechanical properties with low weight and, in particular, also very high thermal properties. has insulation values. In addition, this concrete is extremely waterproof and zu¬ to above 1000 ⁰ C fireproof. Finally, this concrete is extremely inexpensive to produce.

The invention will be explained below with reference to the drawings. Show it

1 shows a flowchart for a method for producing a cementitious building material.

Figure 2 First embodiment of an apparatus for crushing cement clinker.

Figure 3 Second embodiment of an apparatus for crushing cement clinker.

Figure 4 plant for crushing cement clinker.

FIG. 1 shows schematically the sequence of an embodiment of the method according to the invention for producing a cementitious building material.

The starting materials for the production of the cementitious building material, in particular a cement clinker, are obtained by the ecocycling process. According to the ecocycling process, waste of arbitrary composition is comminuted and admixed with additives, whereby a reactive mass is obtained in which an accelerated cold mineralization of the waste material is achieved by separation processes and exothermic oxidation processes, with finely mineralized granules being the end product of this cold mineralization obtained under the brand name C.M500.

From the cold mineralization process, at certain times as intermediate products, a sand-shaped filler, a cement clinker that can be processed into The basic material and a fibrous reinforcement containing silico-caron-fiber structures are used as base materials for producing the cementitious building material, in the present case a concrete. In the present case, 80% filler, 15% cement clinker and 4% reinforcement are used to make the concrete in weight percent.

According to the invention, the cement clinker is comminuted prior to mixing with the remaining components, different arrangements for reducing the size of the cement clinker being described in FIGS. 2-4.

FIG. 2 shows a first exemplary embodiment of a device 1 for grinding cement clinker in the form of particles 2. The device 1 has a hollow-cylindrical comminuting chamber 3 and a likewise hollow-cylindrical collecting chamber 4. The crushing chamber 3 and the collecting chamber 4 have the same diameter and are arranged coaxially along a vertically extending axis of symmetry. In this case, the collecting chamber 4 with its open underside adjoins the likewise open upper side of the crushing chamber 3.

The crushing chamber 3 and the collecting chamber 4 have at their zu¬ facing open ends in each case an annular flange 5, 5 '. Between the annular flanges 5, 5 'is a circular disk-shaped, preferably made of steel be¬ standing baffle plate 6 is mounted. The baffle plate 6 has a predetermined number of openings 7. In the present embodiment, the openings 7 are formed as round holes.

The baffle plate 6 can be mounted on the annular flanges 5, 5 'in a simple manner on the device 1. In particular, the baffle plate 6 can be replaced without major assembly effort and replaced by other baffle plates 6, which may have different arrangements of openings 7. The openings 7 can not only have the shape of round holes but also be designed as angular holes. Also an embodiment of the openings 7 in the form of annular gaps or the like is possible.

In the interior of the crushing chamber 3, two tubes 8, 8 'extend parallel to the longitudinal axis of the crushing chamber 3. In principle, only one tube 8, or 8' can be provided. Furthermore, a larger number of tubes 8, 8 'can also be provided.

The tubes 8, 8 'extend close to each other in the center of the size reduction chamber 3 and open out at the bottom 9 thereof. The Austrittsöffnun¬ conditions of the tubes 8, 8 'at their upper ends are the baffle plate 6 in vorgege¬ benem distance.

In the side wall of the crushing chamber 3, an opening 10 is provided. About this opening 10, the interior of the crushing chamber 3 is filled to a certain level with the particles to be crushed 2.

At the bottom 9 of the crushing chamber 3 two feed pipes 11, 11 'open. The feed pipes 11, 11 'extend in their upper sections parallel to the sections of the pipes 8, 8' protruding beyond the comminution chamber 3. The feed tubes 11, 11 'are curved at their lower ends and extend towards the tubes 8, 8'. In each case, a feed tube 11, IT opens into one of the tubes 8, 8 '. As a result of this design of the tubes 8, 8 ', part of the particles 2 are introduced from the comminution chamber 3 via the feed tubes 11, 11' into the lower ends of the tubes 8, 8 ', so that they have a plug 12 with a specific filling height form. In Figure 2, such a plug 12 is located at the lower end of the right tube 8 '.

At the lower ends of the tubes 8, 8 'in each case a pressure pulse unit 13, 13' with a valve 14, 14 'connects. About the pressure pulse unit 13, 13 ', the plug 12 can be acted upon at the lower end with a pressure pulse of predetermined height and duration. To generate the pressure pulse is at the Valve 14, 14 'gas at a predetermined gas pressure. The gas is preferably formed by air. Alternatively, an inert gas, a cryogen gas or hot gas may be used. By sudden opening of a valve 14, 14 ', the gas flows explosively into the overlying tube 8, 8' and shoots the plug 12 through the tube 8, 8 'on the baffle plate 6. Typically, the height of a pressure pulse in the range between 5 bar and 10 bar. With such pressure pulses, flying speeds of the plugs 12 in the range between 70 m / s and 100 m / s are achieved.

In the embodiment shown in Figure 2, the valve 14 'of the right tube 8' subsequent pressure impulse unit 13 'is closed, so that the plug 12 is in its rest position at the bottom 9 of the tube 8'.

The plug 12 in the left tube 8 is fired by opening the valve 14, the corresponding pressure impulse unit 13 upwards. 1 shows a snapshot, in which the plug 12 is located at the upper end of the tube 8 just before the outlet opening.

After emerging from the respective tube 8, 8 'of the plug 12 hits the baffle plate 6, wherein in the present embodiment, the flight direction is perpendicular to the surface of the baffle plate 6.

It is essential that the duration of the pressure pulse is selected smaller than the transit time of the plug 12 in the respective tube 8, 8 '. Thus, the plug 12 is no longer subjected to the pressure pulse on the route between the outlet opening of the tube 8 8 'and the baffle plate 6. As a result, an undesired fanning of the particles 2 prior to the impact of the particles 2 on the baffle plate 6 is avoided, so that the shape of the plug 12 until Auf¬ meet the particles 2 on the baffle plate 6 at least approximately maintained. Since the particles 2 thus strike the baffle plate 6 in a compact form, the recoil exerted by the baffle plate 6 is propagated through all the particles 2 of the plug 12, so that an efficient and complete comminution of the particles 2 is achieved due to the shearing forces acting on the particles.

As can be seen from FIG. 2, no breakthroughs 7 are provided on the impact surface of the particles 2 on the baffle plate 6, so that no particles 2 are shot directly through the openings 7 into the collecting chamber 4.

FIG. 2 schematically shows the particles 2 reflected and comminuted on the baffle plate 6 and forming a cloud of dust 15. Due to the pressure impulse, an overpressure prevails on the front side of the baffle plate 6, so that the comminuted particles 2 are transported through the apertures 7 into the collecting chamber 4. In this case, only the particles 2 are transported through the apertures 7 up to a predetermined grain size and collected in the collecting chamber 4 behind them, while larger particles 2 fall back into the interior of the comminuting chamber 3 due to their higher weight and again to form further ones Grafting 12 the tubes 8, 8 'are supplied.

By suitable dimensioning of the diameter of the tubes 8, 8 ', the number and sizes of the apertures 7 of the baffle plate 6 and the volume of the collecting chamber 4, the grain sizes and particle size distributions of the collected in the collecting chamber 4 crushed particles 2 can be specified.

The number and sizes of the apertures 7 can be varied by replacing different baffles 6 in a simple manner.

Particularly advantageously, the size of the collecting chamber 4 can be varied. For this purpose, height-adjustable Wellkompensatoren, stuffing boxes, sliding sleeves or the like may be provided, which are not shown in the drawings. In this case, the particle size distribution of the comminuted particles collected in the collecting chamber 4 is the sharper the larger the volume of the collecting chamber 4 is. On the side wall of the collecting chamber 4, a removal opening 16 vorge see. About this Entnahmöfmung 16, the crushed particles 2 can be removed at predetermined times.

The pressure pulse units 13, 13 'are controlled by a control unit, not shown, and generate sequences of pressure pulses in a predetermined time cycle. The pressure pulse units 13, 13 'are preferably controlled alternately, so that alternately a plug 12 is fired from the left or right tube 8 or 8' against the baffle plate 6. The cycles within which the tubes 8, 8 'are filled with the individual plugs 12 are in the seconds or even in the millisecond range, so that the clock rate of the pressure pulses can be selected to be correspondingly high. In this way, the individual plugs 12 are fired rapidly one after the other against the baffle plate 6, so that with the device 1, a quasi-continuous comminution process and a correspondingly high throughput is achieved.

After a plug 12 has been shot from one of the tubes 8, 8 ', the corresponding tube 8, 8' is again filled with particles 2 via the respective feed tube 11, 11 'to form a new plug 12. The advantage here is that the particles 2 are jarred in the crushing chamber 3 and thus reinforced the feed tube 11, 11 'are supplied by the resulting upon firing of a plug 12 shock, whereby the reloading of the tube 8, 8' is supported with a plug 12 , This charging function is further reinforced by the prevailing upon impact of the plug 12 on the baffle plate 6 in the upper region of the crushing chamber 3 pressure.

FIG. 3 shows a second exemplary embodiment of the device 1 according to the invention. The device 1 shown there corresponds almost completely to the exemplary embodiment according to FIG. 2 in its construction. In contrast to the exemplary embodiment according to FIG. 2, the device 1 according to FIG. 3 has two openings 10, 10 'on the side wall of the Zerklei¬ nerungskammer 3, at which filler neck 17, 17' for filling the interior of the crushing chamber 3 with the particles 2 out.

Another difference is that at the lower ends of the tubes 8, 8 ', on which the respective plugs 12 are located, inclined to the tubes 8, 8' ver¬ running supply ports 18, 18 'open. In these feed pipe 18, 18 ', the valves 14, 14' of the not shown separately Druckimpulseinheiten 13, 13 'are arranged.

The longitudinal axes of the feed tubes 8, 8 'may extend in a horizontal, oriented perpendicular to the longitudinal axis of the device 1 level or, as shown in Figure 3 in an inclination angle, which is preferably a maximum of 20 °, inclined to this plane.

Finally, the collecting chamber 4 has two removal arrangements 16, 16 'arranged opposite one another, with a nozzle opening at a respective removal opening 16 or 16'.

Finally, there is a difference from the exemplary embodiment according to FIG. 2 in that the crushing chamber 3 has an upper part 3a whose cross section is slightly smaller than the cross section of the lower part 3b of the Zerklei¬ nerungskammer 3. In principle, the upper and lower part 3 a, 3b also be formed in two parts. At the adjacent open ends of the upper part 3 a of the crushing chamber 3 and the collecting chamber 4, the baffle plate 6 is releasably secured again, so that it can be replaced if necessary.

FIG. 4 shows a further variant of a device 1 for comminuting cement clinker in the form of particles 2. The device 1 shown there has a comminution chamber 3 with a substantially rectangular one Cross-sectional area on. On a longitudinal side of the crushing chamber 3 a plurality of tubes 8 are arranged at a distance, on the opposite longitudinal side a plurality of tubes 8 'are arranged at a distance one behind the other. FIG. 4 shows the device 1 in a cross section, wherein the tubes 8 on the one hand and the tubes 8 'on the other hand are arranged one behind the other in the direction perpendicular to the plane of the drawing. For the compressed air supply of the tubes 8, 8 ', a central pressure air vessel 19 is provided. The compressed air supply to the pipes via valves 14, 14 'from the compressed air tank.

At the top of the crushing chamber is a filler neck 17 for particle infestation. The bottom of the device 1 consists of two mutually perpendicular to each other bottom plates 20, 20 '. The floor plates thus formed form ramps via which particles stored in the bottom area are introduced into the pipes 8, 8 'via feed pipes 11, 11'. *

The baffle plate 6 of the device 1 is formed from the inside of the ceiling of the Zer- ¹ smaller chamber 3. In each case in the center of the baffle plate 6 between two opposite tubes 8, 8 ', an opening 7 in the form of an outlet opening is provided.

The mode of operation of the device 1 according to FIG. 4 is analogous to the functioning of the devices according to FIGS. 2 and 3. When a pressure pulse is generated in a tube 8, 8 ', a plug will explode through this tube 8, 8' as far as the opposite segment Baffle plate 6 shot. There, the crushing of the particles 2. As indicated by the arrows in Figure 4, thereby fall the heavy larger particles 2 back to the bottom of the crushing chamber 3 and are collected there to carry out further crushing processes. The particles 2 with a smaller diameter are guided by the compressed air pulse in the comminution process through the associated aperture 7. In contrast to the embodiments according to FIGS. 2 and 3, in the device 1 according to FIG. 4, the comminuted particles 2 guided through the apertures 7 are not collected in a collecting chamber 4. Rather, the guided through the openings 7 particles 2 are guided in an air flow through pipes 21 and fed via this a cyclone 22. A separation of the comminuted particles 2 contained in the air stream takes place in the cyclone separator 22. The middle fraction of comminuted particles 2 obtained in the cyclone separator 22 typically has particle sizes of up to 45 .mu.m.

The residual air guided out of the cyclone separator 22 is supplied to a filter separator 24 via further pipe conduits 23. There, the residual air is cleaned of fine, comminuted particles, the fine fraction of particles obtained has particle sizes of about 15 μm.

The arrangement according to Figure 4, in particular the device 1 used there, is due to their high capacity and performance in particular for use of place in precast concrete plants. By the series arrangements of pipes 8, 8 'to the device 1 can be achieved with this an extremely high throughput in the crushing of cement clinker.

Pulsar GmbH Micronizing Systems 73457 Aalen-Essingen

LIST OF REFERENCE NUMBERS

(1) device

(2) particles

(3) Crushing chamber (3a) upper part

(3b) lower part

(4) collecting chamber

(5) Ring flange (5 ') Ring flange (6) Baffle plate

(7) breakthrough

(8) Pipe (8 ') Pipe

(9) bottom (10) opening

(10 ') opening

(11) Feed tube (H ') Feed tube

(12) Grafting (13) Pressure pulse unit

(13 ') pressure pulse unit

(14) Valve (14 ') Valve

(15) Dust cloud (16) Removal opening

(16 ') removal opening

(17) filler neck

(17 ') filler neck (18) Feed port (18 ') Supply port

(19) Compressed air tank

(20) Bottom plate (20 ') Bottom plate

(21) Pipelines

(22) cyclone separator

(23) Pipelines

(24) Filter separator

Claims

claims

1. A method for crushing cement clinker for the production of cementitious building materials, wherein the cement clinker is made from products that are obtained by cold mineralization of crushed waste with the addition of additives to accelerate exothermic oxidation processes and separation processes, comprising the following steps:

Collecting a predetermined amount of cement clinker in the form of particles (2) in at least one tube (8, 8 '), the particles (2) forming a plug (12) in the tube (8, 8'),

- Actuation of the plug (12) with a pressure pulse vorgege¬ bener strength and length, so that it is fired via a Austrittsöfmung the tube (8, 8 ') against a pipe (8, 8') downstream baffle plate (6) at least one breakthrough (7) is assigned, whereby the particles (2) which are reduced by the recoil on the baffle plate (6) are guided through the opening (7).

2. The method according to claim 1, characterized in that the baffle plate (6) has a plurality of openings (7).

3. The method according to any one of claims 1 or 2, characterized in that by the recoil on the baffle plate (6) finely crushed particles

(2) pass through the breakthroughs (7) of the baffle plate (6), while coarser particles (2) are returned to the tube (8, 8 ').

4. The method according to any one of claims 1-3, characterized in that the crushed, the apertures (7) passing through particles (2) are collected in a collecting chamber (4).

5. The method according to any one of claims 1- 3, characterized in that the crushed, the apertures (7) passing through the particles (2) we¬ least one separator to be supplied.

6. The method according to claim 5, characterized in that a first separator is formed as a cyclone separator (22) in which zerklei¬ nerte particles (2) are separated from an air stream.

7. The method according to claim 6, characterized in that the cyclone separator (22) is followed by a filter separator (24) for cleaning the cyclone from the separator (22) executed residual air flow.

8. The method according to any one of claims 1-7, characterized in that for the production of the cementitious building material of the crushed cement clinker cement with a sand-shaped filler and a fibrous

Reinforcement is mixed.

9. The method according to claim 8, characterized in that the filler and the reinforcement as well as the cement clinker are obtained by Kaltminerali¬ tion of crushed waste.

10. The method according to any one of claims 1-9, characterized in that the cementitious building material is a concrete.