EP0179782A1

EP0179782A1 - Process for the thermal and/or chemical treatment of grained, granular or lump material

Info

Publication number: EP0179782A1
Application number: EP85901434A
Authority: EP
Inventors: Erich Sundermann; Hanno Laurien; Wolfgang Vahlbrauk; Hans Reye
Original assignee: PERFLUCTIV-CONSULT AG; Perfluktiv-Consult AG
Current assignee: PERFLUCTIV-CONSULT AG; Perfluktiv-Consult AG
Priority date: 1984-03-24
Filing date: 1985-03-16
Publication date: 1986-05-07
Also published as: US4708642A; JPS61501500A; WO1985004467A1; DE3410896A1

Abstract

Dans le procédé de traitement thermique et/ou chimique d'un matériau granuleux, granulé ou en morceaux en tas plats, ces derniers sont transportés avec des intervalles libres, en étages, de haut en bas à travers un puits et sont traversés par des gaz. Les tas s'appuient sur des grilles dont les barreaux peuvent être sortis au moins en partie du plan de la grille temporairement et spatialement, de telle manière que les différents tas sont désagrégés et amenés sous la forme d'un écoulement ruisselant régulier à l'étage suivant si bien qu'est maintenue une épaisseur de couche constante sur la section transversale. L'introduction et l'évacuation des gas s'effectuent par des ouvertures latérales de la paroi du puits dans la section transversale qui n'est pas remplie par les tas. L'écoulement traversant régulier des tas et la déviation de l'écoulement des particules de matériau provoquent un transfert thermique avantageux du gaz sur les particules de matériau ou vice-versa, tout en produisant, lors d'un traitement chimique, une réaction intensive entre le gaz et les particules de matériau avec grande efficacité de la mécanique des fluides.In the process of thermal and/or chemical treatment of a granular, granular or piece material in flat piles, the latter are transported with free intervals, in stages, from top to bottom through a well and are passed through by gases . The piles are supported on grids whose bars can be taken out at least partly from the plane of the grid temporarily and spatially, in such a way that the different piles are disaggregated and brought in the form of a regular trickling flow to the next floor so that a constant layer thickness is maintained over the cross section. The introduction and evacuation of gases takes place through lateral openings in the wall of the well in the cross section which is not filled by the piles. The regular flow through the piles and the deviation of the flow of the material particles cause an advantageous heat transfer of the gas onto the material particles or vice versa, while producing, during chemical treatment, an intensive reaction between gas and particle material with high fluid mechanics efficiency.

Description

Process for the thermal and / or chemical treatment of granular, granulated or lumpy material.

The invention relates to a method and a device for the thermal and / or chemical treatment of granular, granulated or lumpy material in piles, in which the piles are separated from one another in a plurality and leave free spaces between

Pile-to-pile in a shaft and after predetermined dwell times in the individual floors, in batches starting with the lowest pile by conveying it through the shaft from top to bottom and in the shaft with gases or vapors introduced into the gaps.

A method and a combustion shaft for cement, lime, gypsum or the like which serves to carry out the method are known (DE-PS 31 932), in which the shaft interior and the column of material located in the shaft interior, completely filling the shaft, by rust-like, and Partitions pullable laterally from the shaft walls is divided, so that with the Well-filled quayters result between grids arranged one above the other. The fuel gases are introduced into the interior of the shaft below the bottom grate and flow upwards through all the chambers or the material in the chambers. When the material on the bottom rust-shaped partition, such as lime or the like, has been fired sufficiently, the fired product is discharged by pulling out the divided bottom partition before the next chamber filling is transferred to the firing zone on the bottom firing wall after the partition has been closed and then all the chamber fillings above it are transported down one floor and the top partition is loaded with the goods again.

This should enable continuous operation of the shaft furnace.

With this known method, with regard to the column of material to be flowed through by the fuel gases, only low flow velocities of the fuel gases can be achieved, which lead to long residence times of the material on the individual floors.

The procedure is also based on the treatment of such

Good limited, in which the fuel gases can also be used for preheating at the same time. Finally, bridging and a consequent uneven flow are unavoidable, and in particular in the firing zone such bridging can occur which has a correspondingly disadvantageous effect on the uniform preheating of the material with regard to the flow distribution in the chambers above. After all, there are considerable difficulties to achieve complete emptying of the chamber located above this grate and a corresponding complete filling of the chamber underneath through the divided grids which can be pulled out laterally from the wall. The resulting irregularities result in additional irregularities in the heating of the material within the individual cross-sectional levels of the shaft. The fuel gases supplied from below inevitably result in a very large shaft height, which in turn must lead to a further reduction in the flow velocity of the fuel gases and the associated disadvantages.

It has also become known to treat porous aggregates from expandable material in the manner described in the introduction (DE-AS 1 165 477). The broken material, such as clay or oil shale, is placed in chambers one above the other of a shaft, and each chamber is only partially filled. The chamber floors consist of slats that can be rotated about their longitudinal axis. Between the pile located in the respective chamber and the floor of the next chamber located above it, there is an intermediate space in which are arranged laterally in the walls of the shaft

Burners generated fuel gases are introduced. To avoid the formation of bridges in the material, the aggregates are loosened mechanically by the fact that the floors are driven in rotation and equipped with teeth pointing downwards, which extend into the vicinity of the next floor.

In order to improve the above-mentioned prior art, a further development has become known (DE-AS 1 243 827) with combustion chambers provided on both sides of a shaft, which combustion chambers have openings in the shaft Wall are connected to the interior of the shaft, the interior of the shaft is in turn divided into compartments by floors made of rotatable flaps. Appropriate control of the bottom flaps of the individual shaft chambers and a charging device alternately covering the two combustion chambers is intended to alternately blow on the material falling from chamber to chamber and thereby to achieve a swirling with the aim of a more uniform heating of the individual good particles.

In all known methods described, there is a very uneven heating of the individual good particles, which leads to the fact that part of the good overheats and another part is not sufficiently heated to the respectively required final temperature, so that only an uneven thermal and / or chemical treatment of the goods can be achieved.

In the last-described methods and devices, there is the further disadvantage of a relatively low energy yield of the fuel gases, since they either only sweep over the respective chamber floors and the surfaces of the piles of the material to be treated or flow around the material practically exclusively during the short period of free fall , so that a corresponding number of chambers is required depending on the desired temperature of the material to be heated.

The invention has for its object to develop a method of the type described in the introduction so that a uniform thermal and / or chemical treatment of all good particles is achieved on each floor and thereby a reduction in the residence time is achieved and also a different temperature control and a treatment the goods on the individual floors with differently composed gases or vapors is made possible.

To solve the above problem, the method mentioned in the introduction is characterized in that good parts of approximately uniform grain or piece size with approximately the same longitudinal and corresponding transverse dimensions in the range from 6 to 100 mm are produced or obtained by preparation and at the latest when they are transferred into the shaft a uniformly metered distribution over an area that corresponds to the cross-sectional area of the shaft, in each case transferred to piles with the same layer thickness over their cross-section, and the commercial structures in the shaft are each supported by grates, so that the piles at least during one or more dwell times on the grids by means of the side Gases or vapors discharged into and out of other spaces in some of the spaces in the direction perpendicular to the layer plane and after a predetermined dwell time by moving at least a portion of the grate bars in a time-controlled manner us dissolved in the grate level and fed as a uniform trickle flow to the next grate in such a way that they again form piles with the same layer thickness over their cross-section.

By means of the above-mentioned method, the treatment of different goods is possible, whereby either heating or cooling or both can be carried out in succession, just as it is possible to achieve the granular or lumpy goods without targeted temperature influence, that is to say at approximately constant temperatures treat certain chemical reactions with a gas. Some practical process cases include deacidification of lime, dolomite, gypsum, magnesite or apatite, hardening, carburizing, nitriding or tempering metallic materials as well as tempering and tempering non-metallic, organic materials, drying granules containing aluminosilicate to prepare the subsequent expansion process , the freezing of food with the above-mentioned grain or piece size, such as small baked goods or rolls or the like.

To achieve the uniform treatment of the individual good parts, it is important that they form piles of constant layer thickness in the individual floors, whereby due to the approximately uniform size of the particles there are sufficient gap spaces between them through which the guided gases or vapors are passed, around which to flow evenly around individual good particles and at the same time to achieve an intensive swirling of the gases or vapors in the void spaces, through which an improvement in the heat transfer from the good particles to the gas or vice versa is achieved during the thermal treatment and through which an intensive treatment takes place simultaneously during the chemical treatment Touch of the constituents of the gas with the surface of the good particles is achieved and thus an intensification of the reaction between the good particles and the gases or vapors.

Since the supplied gases or vapors are introduced laterally through the shaft wall into the gaps between adjacent piles and, after flowing through the piles in the direction perpendicular to the layer level, they are laterally discharged from the shaft, the piles can be used on the individual floors or in groups of floors with gases or steaming different temp temperature or different chemical composition are applied, for example, to achieve a cooling of the good particles after a previous heating, or to end a previous chemical treatment or to interrupt in the meantime.

The grates that allow the material to flow through the heap enable the trickle flow of the material over the entire cross-sectional area of the floor, which is favorable for the uniform layer formation in the next floor, when at least part of the grate bars are moved out in a controlled manner. The desired trickling movement can be generated either by a time-controlled lowering and / or by a time-controlled lifting of a part of the grate bars, the lifting paths or lifting heights and the transfer of the grate bars into two or three different levels depending on the respective good and the shape of the good particles can be adjusted, the most favorable results can be predetermined by appropriate trickle tests. The controlled grating movement described also destroys any good bridges that may arise on individual floors.

The direction of the flowing through the piles

Gases or vapors can be selected differently in accordance with the subclaims, the layer thickness and the temperature or concentration gradient of the gases or vapors playing an important role.

It has been found that when heating up a good, the heating power with mutual flow through a bed, which with the aim of equalizing the temperature in the bulk material when convectively heating it may be desired, is less than the heating power in one-sided convective heating under otherwise the same conditions.

In order to take advantage of the one-sided flow also for the process in which the gases enter the shaft-like enclosure in every second space between the piles and exit from the other spaces, the direction of flow of the gas flow is determined during the period in which the

Bulk bodies continue to fall to the next stage, switched.

This reversal of the gas flow direction results in the advantageous unilateral gas flow for each individual bulk body in the process described during its entire stay in the shaft.

The flow rate, based on the free cross-section of the shaft, i.e. when the material flows against it, is 1 m per second in the new process. up to about 4 m per second, the average pile height is in the order of 0.1 to 0.3 m depending on the grain or piece goods size, and the cycle times, i.e. the respective treatment time on the individual floors is of the order of 2 to 10 minutes. The trickle time is usually 2 to 4 seconds.

Through the described guidance of the gases or vapors, it is possible to subject these gases or vapors to an intermediate treatment after flowing through one or more heaps, for example to carry out intermediate cooling or intermediate heating, or to increase the concentration of the gases or vapors with regard to their active substances in chemical reactions or decrease depending on what interactions between the gases or vapors and the heaps are to be achieved.

When treating a pile that tends to form denser packs or bridges, it may be expedient to partially screen the pile with a flow from below, at least for some dwell times, in places alternating against the inflow and flow of gases or vapors and in the other areas flow through until the loosening point of the goods is reached or exceeded. If the partial intensive flow in the course of the loosening and movement of the good particles partially transfers them to those areas that are not flowed through, they are returned when the partially flowed through and non-flowed areas change, so that the uniform layer thickness of the good is despite this partial loosening and movement of the goods is preserved.

Practice shows that in many cases one or more piles in the shaft are expediently shielded against the flow of gases or vapors. This is useful, for example, for the uppermost pile in the shaft, which at the same time is one

Forms a barrier layer against the gases or vapors flowing through the pile below. Such barrier layers can also be provided between different treatment zones provided in a common shaft, in which the treatment zones between them

Treatment areas located piles are shielded against the flow of gases or vapors.

Devices for carrying out the method proceed from a shaft, the interior of which is divided into chambers for receiving the piles by intermediate floors, the adjustable floor elements for the batch-wise conveying of the piles through the shaft and in the shaft walls have free passage openings to at least part of the chambers.

According to the invention, these devices are characterized in that the intermediate compartments for forming the chambers consist of grates and all grids at least partially consist of movable grate bars with actuating devices and controllable drive devices associated therewith for temporarily enlarging the free spaces between adjacent grate bars by moving a part of the grate bars out exist on the grate level, and that gas or steam supply and discharge lines are connected to the control openings associated with the passage openings in the shaft walls.

The shaft walls can be designed very differently depending on the type of use. For example, when used for firing processes, they can be provided with correspondingly heat-resistant linings or, when used for deep-freezing, with appropriate heat insulation, the structure consisting of module parts which are closed in a ring shape and each with a grate and passage openings in the walls for the supply and discharge of the gases or vapors is particularly cheap in order to be able to manufacture manholes of different heights from largely prefabricated parts.

Further expedient refinements of the shaft result from the features of the corresponding subclaims, in which also constructive training to achieve the above-described alternate partial flow and the possible shielding of individual ones Piles are described.

The drawing shows a schematic representation of exemplary embodiments for devices for carrying out the method in connection with some application examples.

Show it:

1 shows a longitudinal section through a shaft according to the invention with different treatment zones of the material, FIG. 2a shows, on an enlarged scale, part of the sectional view according to FIG. 1 at the level of a grate from which details of the grate arrangements can be seen, FIG. 2b shows a plan view of FIG 2a, 3a and 3b possible positions of the grate bars in their arrangement and design according to FIGS. 2a and 2b,

4 shows a perspective view of two grate bars with partially mounted rider-shaped profile parts, FIG. 5 shows a partial top view of grate bars according to FIG. 4 with attached rider-shaped profile parts,

6 shows a partial longitudinal section through the area of the lowest level of the shaft according to FIG. 1, FIG. 7 shows a view from below against the flaps according to FIG. 6 arranged distributed over the shaft cross section, FIG.

8 shows an enlarged illustration of a cross section through one of the flaps according to FIGS. 6 and 7, FIG. 9 shows a partial longitudinal section through a shaft with grids that can be inserted laterally, FIG. 10 similarly shows a longitudinal section through a shaft

Fig. 1 for drying granules from alumino silicate-containing raw material, such as clay or the like, on which the process sequence of the above

11 is a sectional view through a shaft for calcining lime, on which the method example of lime burning according to the invention is explained, FIG. 12 is a sectional view through a shaft similar to that

10 and 11, on which the cooling of cement clinker is explained as a process example.

The shaft shown in FIG. 1 has a shaft wall denoted overall by 1 and has a square or rectangular cross section. In the shaft 1 grids 2 are arranged at intervals one above the other in the walls so that each chamber 3 is formed between adjacent grids, which only partially. are filled by flat piles 4 of the granular or granular or lumpy material to be treated, so that a free space remains between each surface of the piles 4 and the grate 2 located above them.

In the example shown, the shaft is composed of annularly closed and stacked module parts 5, each with a grate 2 held therein, so that the shaft can be created by a corresponding number of module parts 5 at different heights and with a correspondingly different number of floors. At its lower end, the shaft is equipped with a discharge opening 9, which can be closed by a slide 10, for the material treated in the shaft. Below the shaft, a conveyor 11 can be seen, on which the material emerging from the shaft is fed for further processing or processing. At the top, the shaft is closed by an end housing 6 designed as an entry lock. In the laterally protruding part of the end housing 6, a metering and distributing device 7 is shown schematically, in which the quantity of the goods intended for a pile 4 is received and from which it is displaceable in the form of a flat pile with the same layer thickness over the cross section Mold box 8 is transferred, which is closed at the bottom by a grate, which the

The grate 2 in the module parts 5 of the shaft corresponds and is equipped with an actuating device (not shown in the drawing) in order to move at least some of the grate bars out of the grate plane, as will be described in connection with the grates 2.

In the wall 1 of the shaft in the chambers 3 or in the free spaces formed by the chambers, outflow or outflow openings 12, 12a,

13 _> 13a and 13b 'and 14 and 15 are provided, which are connected to corresponding gas supply and discharge lines not shown in the figure and which in turn lead to conveying devices or to devices for the treatment of the gases or possibly also the vapors, depending on the gases or vapors with which the material in the piles 4 is to be treated.

In the shaft shown in FIG. 1, between the two uppermost grids 2 and the two uppermost chambers 3, a partition wall is provided, which is formed from pivotable slats 16 and can be converted into the closed and open positions by adjusting the slats. A similar partition made of fins 16 is between the in

Lower chamber and the chamber above arranged. Finally, below the bottom grate 2 in the shaft, the arrangement of a grate-shaped insert 29 can also be seen, which serves to form parallel flow channels 30, and in which flaps 17 are arranged and can be rotated about horizontal axes 27, 28 and partly assume a blocking position and partly a passage position .

The grids 2 arranged in the shaft consist, according to FIGS. 2a and 2b, partly of fixed grate bars 18 and partly of movable grate bars 19 and 20, the latter being movable upward from the grate plane in relation to the fixed grate bars 18 in order to free the spaces between adjacent ones To temporarily enlarge grate bars.

2a, the position of the grate bars 18 to 20 in the grate plane is shown in the left part, while the grate bars 19 and 20 are shown in different positions in relation to the grate plane in the right part. To raise the grate bars 19 and 20 are provided in niches 21 on the inside of the shaft wall 1 provided crank or swivel arms 22 which can be pivoted from the outside via an actuating shaft 23. The movable grate bars 19 and 20 are elongated compared to the fixed grate bars 18 and combined to form a unit that can be raised and lowered, the lengthening of the grate bars 19 and 20 according to FIG. 2a having the form of crankings 19a and 20a of different lengths. This has the consequence that when the crank arms 22 pivot about the pivot axis 23, the grate bars 19 and 20 are transferred to different heights, as can be seen in the right half of FIG. 2a.

Instead of lifting the movable grate bars 19 and 20 conversely, a lowering of these grate bars can be provided, so that depending on the stroke or. Lowering movement of the grate bars 19 and 20 can result in different positions of the grate bars relative to one another, as are shown, for example, in FIGS. 3a and 3b.

The grate bars shown schematically in FIGS. 2a and 2b expediently have the shape shown in FIGS. 4 and 5 in practice. It can be seen that the grate bars, which can be designed as solid or hollow profile bars, have an undercut profile 24 in cross section in their upper part and are equipped with pushed-on replaceable rider-shaped profile parts 25 which are pushed onto the grate bars. The tab-shaped profile parts are horseshoe-shaped and equipped with projections 26 pointing in the longitudinal direction of the grate bars as stops with adjacent tab-shaped profile parts. When the tab-shaped profile parts are packed tightly on the grate bars, the grate bars have a shape as can be seen in the top view of FIG. 5 of two adjacent grate bars.

The rider-shaped profile parts 25 have the effect that the bottom layer of the material in each pile 4 cannot close the gaps between adjacent grate bars, even if the material should consist of cylindrical particles, in which without the rider-shaped profile parts 25 by the rolling movement of the material particles with a row-shaped Arrangement in the spaces between the grate bars must be expected. The rider-shaped profile parts can have a different diameter at a predetermined spacing of the grate bars, so that the percentage of the free flow cross-section through the grilles 2 can be set or changed accordingly. It is also possible to influence the local flow conditions by using tab-shaped profile parts 25 of different cross-sections.

The shaft shown in FIG. 1 can be provided, for example, for heating or also for cooling a material to be treated in the pile 4. For this purpose, the passage openings 12 and 12a can be connected to a blower, while the passage openings 13, 13a and 13b are connected to a common gas discharge line, which may be part of a circuit line and e.g. can in turn be connected to the blower via a heat exchanger. The lowest pile 4 in the shaft can be acted upon by supplying a different or differently tempered gas and discharging it, or possibly also by means of a gas circuit through the inflow and outflow openings 14 and 15. In this case, the lattice-shaped insert 29 in connection with the flaps 17 in the lowermost pile can partially flow through this pile and, by setting appropriate flow rates, the loosening point of the material in the pile can be reached or exceeded, so that in the area of flow through channels 30, a partial movement of the good particles takes place and these come through the loosening and the flow into the area of the non-flowed fields. By changing the position of the flaps 17, a return and reverse movement of the good particles can be achieved. This method of operation is particularly favorable if the particles of good should tend to stick together when flowing through the lowest pile. The lamellae located above the lowest pile results in the lowest

Haufwerk a separate treatment zone. That forms an additional barrier layer above which the lower slats 16 have an additional barrier layer and no treatment gas flows through them. In contrast, in the example shown, the next four piles in the vertical direction are flowed through when the passage openings 12 and 12a are connected to a gas supply line in the direction of the arrows, partly from top to bottom and partly from bottom to top, and the treatment gas through the outlet openings 13, 13a and 13b removed. The outlet openings mentioned can be connected to a common gas discharge line. By suitable control devices, the direction of flow of the gases can be reversed without difficulty with respect to the arrows shown, so that a change in the directions of flow during the dwell times of the

Piles in the individual floors is easily possible.

The second heap from above in the illustrated shaft according to FIG. 1 again forms a barrier layer, since above this heap there is a further partition wall formed by pivotable lamellas lβ, which is in the closed position during the flow through the heap. This pile is formed in the period of time during which the other piles are flowed through in the manner described.

When the lowermost pile in the shaft has reached its final state desired by the flow, by moving the movable grate bars of this grate into the open position, the pile is dissolved and transferred to the far conveyor 11 when the slide 10 is open. After the movable grate bars have been returned to the level of the fixed grate bars, the pivotable lamellae above this grate are pivoted into the open position and controlled by a time-controlled First actuation of the grate bars of the grate arranged above these lamellae, the pile located thereon is dissolved in the manner already described and passed on in the form of a flat trickle stream to the lowest grate by free fall in such a way that a layer thickness which is constant over the shaft cross section is achieved. This process is repeated from grate to grate until the top rust in the shaft is free. When the slats 16 provided in the upper part of the shaft are in the closed position, the material for forming the uppermost pile is then transferred into the shaft by means of the displaceable molding box 8.

In the described mode of operation of the shaft according to FIG. 1, depending on the type of goods and gases

Drying or heating or cooling of the goods are carried out and / or chemical treatment of the goods is carried out using appropriate gases or vapors.

Some examples of various types of good treatment are described in connection with FIGS. 10 to 12.

First, however, reference is made to FIGS. 6 to 9, which show details with regard to the arrangement and design of the flaps 17 which can be rotated about their horizontal axes within the flow channels 30 of the grating-like insert 29. The flaps 17 are held in the flow channels corresponding to the fields of a chess board in such a way that flaps lying next to one another each assume a different position. In order to be able to adjust the positionally identical flaps 17 of each row, two superimposed horizontal axes 27 and 28 according to FIG. 8 are provided, on which the flaps 17 of each row are held alternately. In the practical embodiment according to FIG. 8, the flaps 17 held on the axis 27 take off saving the axis 28 of the adjacent flaps, without these axes 28 hindering the pivoting movement of the flaps held on the axis 27. In this way it is possible to move all flaps into the locked position or all flaps into the open position or the adjacent flaps into different positions.

If in the duct with high temperature gases, i.e. Should be in the order of 1,200 to 1,600 ° C, the grate bars described and all load-bearing parts of the grates as well as the grate-shaped insert 29 and the flaps 17 held therein with the load-bearing axes 27 and 28 are made of SiSiC or reaction-sintered SiC and Expediently provided with a covering layer made of boron nitride in order to prevent these good particles from adhering to the aforementioned parts of the grate or grate-shaped insert in the event of a melt flow occurring on the surface of the individual good particles.

Instead of the modular construction of the shaft described in connection with FIG. 1, the shaft wall 1 can also be designed as a continuous shaft wall and, in accordance with the example in FIG. 9, have window openings 31 into which the gratings in the form of the structural units already mentioned can be inserted laterally. The grids, which consist of fixed and movable grate bars in the manner described, are held in groove-shaped recesses 32 of the side shaft walls by means of a support device 33. To close the window opening 21 in the shaft wall 1, an adapted filler 34 is used in conjunction with a cover plate 35 which is screwed to the shaft wall 1 after the filler 34 has been inserted. By the aforementioned te training, it is possible to replace the grids designed as a structural unit at short notice with little effort.

The shaft shown schematically in section in FIG. 10 shows a largely identical structure with the shaft shown in FIG. 1 and described above. In FIG. 10, the parts corresponding to FIG. 1 are also provided with the same reference numerals.

10, the method for drying granules from aluminosilicate-containing raw material will be described in more detail.

The shaft is in turn made up of module parts 5 with gas inlet or outlet openings provided in the walls of these module parts. Due to the lamellae 16, which are arranged one above the other at intervals and each form a partition, the height of the shaft is divided into four sections I to IV, as indicated laterally next to the shaft view. The uppermost section I represents a soaking section for the material introduced into the shaft from above, to which the three drying sections II to IV are connected at the bottom.

It is assumed that in the illustrated duct, granules in the form of cylinders have longitudinal and transverse dimensions of approximately 16 mm with a humidity of approximately 20%. With pile dimensions of 100 x 1,200 x 1,200 mm determined by the shaft cross-section, a pile weight of approx. 250 kg results.

The distance between the grate bars and the rider-shaped profile parts arranged on the grate bars are thus ge chooses that the portion of the gas passage area is about 38% when the grate is closed.

The gas is fed to the heaps at a flow rate of approximately 0.9 m per second.

The supply and discharge of the hot gases or hot air flowing through the heaps can be seen from the circuit arrangement shown schematically in FIG. 10 and from the arrows drawn in, the partially dashed illustration of the double arrows also showing the possibility of reversing the flow through part of the heaps is recognizable.

The supply of the heated air or hot gases to the soaking section I is carried out by a blower 31 and the supply of the air to the third drying section IV by a blower 32. In the circuit arrangement, heat exchangers 33 and 34 operated via burners or other heating devices can be seen, between the

Drying sections II and III or III and IV are provided. A rotary slide valve 35 in the form of a four-two-way valve can also be seen in the area of the drying section II.

In the heat-through section I, a gas which has a temperature of approximately 150.degree. C. flows through one side in the direction of the arrow shown in the direction of the arrow shown, through the blower 31, through the blower 31 located underneath the uppermost barrier pile. In drying section II there is a mutual flow of the material on the grates located there with a gas which has a temperature of approx. 200 ° C. In drying sections III and IV, the material is heated to the maximum permissible temperature for drying of about 200 °, the drying section IV by means of the blower 32, the gas supplied to the shaft after the flow through the two lowermost piles through the heat exchanger 33 is reheated before it is fed to the piles in the drying section III, from which it passes through the heat exchanger 34 and the fan 36 arranged downstream thereof into the drying section II reached.

The dwell time of the individual piles on the grates is about 3 minutes, while the trickling time when transferring the piles to the next subsequent grate is about 2 to 4 seconds.

A somewhat different design and mode of operation of the shaft is shown in FIG. 11. This figure shows a chute designed according to the invention for the burning of lime.

In this figure, too, the parts of the shaft already described in the previous figures are provided with the same reference numerals as in the aforementioned figures.

The shaft according to FIG. 11 is again made up of modular parts 5 and, in this example, is divided into three sections over its height, which extend to the upper piling below the partition consisting of the lamellae 16 to the discharge opening 9.

The upper section A represents the preheating zone, which extends over three heaps. This is followed by section B as a firing zone, over a height of six piles. Section C, which then follows downward, is the cooling zone, in which there are a total of four heaps. The flow guidance is again shown in the circuit diagram. This shows the supply of the cooling air via a blower 37 to the lowest pile as well as the supply of burners 38 generated from the burner provided outside the shaft to the individual free flow cross sections between the piles of the combustion zone B. The gases are removed from the shaft above the uppermost pile of preheating zone A via a blower 39. The arrows shown show the flow guidance and the possible return or

Circulation of part of the gases through the individual zones.

In the example shown, the process gas flows in the entire shaft furnace in counterflow to the material. The cooling air entering the cooling zone C flows through the heaps located in the cooling zone and is heated and mixed with combustion gases from the burners 38 and transferred to the combustion zone B and from the combustion zone B to the preheating zone A, from which it is then removed. To control the pressure conditions in the combustion zone, the suction fan 40 makes a very significant contribution in the course of the return line for part of the combustion gases in the combustion zone B. By appropriate adjustment to the blowers 37 and 39, a very sensitive control of the pressure conditions can be carried out over the entire height of the shaft.

When treating lumpy lime with a particle size of 10 to 20 mm and heap heights of around 16 cm and gas temperatures of around 1,200 ° C in the area of the firing zone B, there are dwell times of the heap on the individual grates when the shaft is formed according to Fig 11 of about 6 minutes if the gas flow rates in the combustion zone B in the free spaces between the piles of about 2 to 4 m per second can be set. The trickle time for transferring the individual piles from rust to rust is of the order of 2 to 4 seconds.

The formation of a shaft for cooling cement pellets can be seen in a schematic representation from FIG. 12, which also shows the relatively simple circuit arrangement for the cooling air duct.

Also in FIG. 12, the parts that correspond to the other shaft representations according to FIGS. 1, 10 and 11 are provided with the same reference numerals.

The shaft shown has a total of eight floors or

Gratings 2 with piles 4 located thereon, which are held in the interior of the shaft below a blocking pile plant and a partition made of swiveling slats Iβ located above. The cooling air is supplied via a blower 41 into the space below the lowest pile. This cooling air flows through the heaps from bottom to top, whereby part of the cooling air supplied after flowing through the bottom two heaps and another part of the cooling air after flowing through the bottom four heaps in the direction of arrows 42 and 43, while the other Part of the cooling air flows through the four further heaps that follow upwards and is discharged below the barrier heave in the direction of arrow 44. By appropriate arrangement of controllable throttle arrangements in the air discharge lines, which are not shown in the drawing, the portion of the cooling air emerging from the shaft in the direction of arrows 42 to 44 can be used to achieve a desired temperature gradient of the material seen above the height of the shaft. The cooling air exiting in the direction of arrows 42 to 44 and heated differently can, if necessary, be returned in a circuit to the blower 41 via heat exchangers for recycling the heat energy removed from the shaft, a dust separation being naturally also provided in this circuit, since the for all shafts designed according to the invention, similar transfer of the piles through the shaft from top to bottom from floor to floor due to abrasion cannot be avoided.

For all the exemplary embodiments shown, it is important that in each case flat piles having the same height over the cross-section of the shaft are introduced and this shape also after their transfer from rust to rust by means of a correspondingly controlled movement of the grate bars and a uniform trickle flow of the material produced thereby are retained, the necessary sequence of movements for the grate bars possibly having to be determined by trickle tests depending on the structure and type of the goods.

The structure described and the mode of operation of the new one

In addition to making the flow through the heaps more even, the shaft also improves the fluid mechanics of the effectiveness, ie the ratio of the transmitted power to the mechanical power used. With the new shaft, compared to conventional shaft arrangements, the treatment time of the goods can be reduced by up to 25% and sometimes even less, and gentle treatment can also be achieved. When operating the shaft using gases with higher temperatures up to 1,350 ° C, the material for the grate bars and the other load-bearing parts of the grates, as well as with the arrangement of a grate-shaped insert for this use and the flaps and axes held therein, SiSiC and at Reaction-sintered SiC has proven itself at higher temperatures up to 1,600 ° C.

Claims

Expectations

1. A method for the thermal and / or chemical treatment of granular, granulated or lumpy material in piles, in which the piles are separated in a plurality and stacked in a shaft, leaving empty spaces from piles to piles, and after predetermined dwell times in the individual floors in batches, starting with the lowest pile by conveying it from top to bottom through the shaft and in the shaft with gases or vapors introduced into the intermediate spaces, characterized in that good parts of approximately uniform grain or piece size with approximately the same length and length these corresponding transverse dimensions in the range from 6 to 100 mm or obtained by processing and at the latest when transferred into the shaft by a uniformly metered distribution over an area that corresponds to the cross-sectional area of the shaft, each in piles m it is transferred over its cross-section of the same layer thickness and the heaps in the shaft are each supported by grates, so that the heaps at least during one or more dwell times on the grates by means of gases or vapors discharged laterally into and out of some spaces in the direction perpendicular to Flows through the layer level and after a predetermined dwell time by a time-controlled removal of at least some of the grate bars from the grate level and dissolved as a uniform trickle stream to the next grate so that they again form piles with the same thickness across their cross-section.

2. The method of claim 1, that the gases or vapors flow through the piles at least during some dwell times in one direction and during other dwell times in the opposite direction.

3. The method of claim 1, that the gases or vapors are alternately flowed through in opposite directions at least over the duration of one or more dwell times during these times.

4. The method according to claim 1, characterized in that the gas is introduced into every second space between the purchasing units in the shaft and is led out of the other spaces between the piles exiting the shaft, and that alternately a pile during all dwell times in the shaft flows upwards and one flows downwards.

5. The method according to any one of the preceding claims, d a d u r c h g e k e n n z e i c h n e t that the heaps are temporarily exposed to such an intense gas or steam flow when flowing from bottom to top that the loosening point of the free-flowing material is reached or exceeded.

6. The method according to claim 5, dadurchge ke nnzeich that the heap with a flow from below at least during some dwell times locally alternating against an inflow and outflow of the gases or vapors shields and in the remaining areas until the loosening point of the goods is reached or exceeded.

7. The method according to any one of the preceding claims, d a d u r c h g e k e n n z e i c h n e t that one or more piles in the shaft are shielded against a flow of gases or vapors.

8. Device for performing the method according to one of claims 1 to 7 with a shaft, the interior of which is divided into chambers for receiving the piles by intermediate floors, the adjustable floor elements for batch-wise conveying of the piles through the shaft and in the shaft walls free passage openings at least have a part of the chambers, characterized in that the intermediate floors to form the chambers (3) from grids (2) and all gratings at least partially from movable grate bars (19, 20) with actuating devices (22, 23) and controllable drive devices assigned to them for temporary use Enlargement of the free spaces between adjacent grate bars by time-controlled moving these grate bars out of the

Grate level exist, and that with the passage openings (12, 12a; 13 to 13b) in the shaft walls (1) gas or steam supply and discharge lines are connected to these associated control devices.

9. The device according to claim 8, characterized in that above or in the upper part of the shaft means (7,8) for evenly distributing the goods over the shaft cross-section on a grate forming the bottom of a distribution chamber (2) is provided.

10. Device according to one of claims 8 or 9, characterized in that the movable grate bars (19, 20) of each bar grate (2) by connecting their ends (19a, 20a) form at least one structural unit, which by the actuating device (s) (22, 23) can be moved out of the plane of the fixed grate bars.

11. The device according to claim 10, so that the or each unit formed from the movable grate bars (2) is movable by means of a lifting device into a plane outside the plane of the fixed grate bars (18) and is held traceable to the plane of the fixed grate bars.

12. The apparatus according to claim 10 or 11, characterized in that the movable grate bars (19, 20) of the or each structural unit over the fixed grate bars (18) are extended and are connected to one another via these extensions (19a, 20a), and that A crank mechanism (22, 23) acting on the interconnected ends of the grate bars is provided as the lifting device.

13. Device according to one of claims 10 to 12, d a d u r c h g e k e n n e e c h n t that several structural units of movable grate bars (19, 20) are provided per grate (2) and can be transferred to different levels outside the plane of the fixed grate bars (18).

14. The device according to one of claims 9 to 11, characterized in that the shaft from annularly closed-module parts (5) each with a grate (2) and at least partially with through openings (12, 12a or 13 to 13b) in their walls (1) for the supply or discharge of the

Gases or vapors is built up.

15. The device according to one of claims 8 b-is 14, d a d u r c h g e k e n n z e i c h n e t that the gratings (2) are designed as units that can be inserted laterally through exposed windows (31) in the shaft wall (1).

16. Device according to one of claims 8 to 15, characterized in that in each case below the fixed grate bars (18) in the shaft walls (1) on the inside of the shaft recesses (21) for receiving the actuating devices (22,23) for the movable grate bars (19th , 20) or the structural units formed by them and drive devices for the actuating devices are arranged outside the shaft wall.

17. The device according to one of claims 8 to 16, characterized in that the grate bars (18 to 20) seen in cross section in their upper part have an undercut profiling (24) and are fitted with pushed-on replaceable rider-shaped profile parts (25) which close prevent the spaces between adjacent grate bars through the goods.

18. The apparatus of claim 17, so that the rider-shaped profile parts (25) are horseshoe-shaped with projections (25) pointing in the longitudinal direction of the grate bars (18 to 20) as stops with adjacent profile parts.

19. Device according to one of claims 8 to 18, characterized in that beneath some grids (2) a grate-shaped insert (29) is provided to form parallel flow channels (30), and that flaps (17) rotatable about horizontal axes in the flow channels are provided which can be swiveled alternately or in groups in the shaft plane or perpendicularly to the fields of a chessboard.

20. Device according to one of claims 8 to 19, d a d u r c h g e k e n n z e i c h n e t that below at least one of the gratings (2) one after

A partition made of pivotable slats (16) that can be moved into the closed and open position is provided as a type of slatted blind.

21. Device according to one of claims 8 to 20, characterized in that the grate bars (18 to 20) and the other load-bearing parts of the grids (2) and in the arrangement of a grate-shaped insert (29) and the flaps (17) and held therein Axes (27, 28) consist of SiSiC or reaction-sintered SiC.