DE1667162A1 - Device for performing chemical processing - Google Patents

Description

Dr. EMIL VORWERK ^ _{31 GRD} benzell / Munich, "March 18, 1968

PATENTANWALT Mozartstr.9 ■ Telephone 08142 / fl & _e Telephone no.

Postal checking account: Munich 175659 UU1 42/6359 Bank. Deutsche Bank Munich, branch. Maximilianstrasse, Account 41/36230

L 335/68 DrV / sw

IHE LUlMJö COMPAIiX
5 3road Street, Bloomfield, l-'ew Jersey O7OO3 (V.St.A.)

Apparatus for performing chemical processing

The invention relates to chemical processing apparatus and, more particularly, to a multi-chamber processing vessel with a plurality of processing zones, in which successive stages of a continuous chemical process successively in continuous Sequence can be carried out. The device according to the invention is useful for a variety of chemical, physico-chemical or physical / experienced; she will however, in the following, for the sake of simplicity, primarily using the example of the production of phosphoric acid from phosphate rock explained. It is readily apparent that the previous, when using conventional devices for the ixers division of phosphoric acid occurring difficulties

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and achieved technical advantages apply when using the device according to the invention _b leicner way for numerous other chemical Verarbeitungsmaßnahinen.

The device according to the invention essentially comprises a container with a plurality of chambers formed by inner (partition walls including an inlet chamber, at least one intermediate chamber and an outlet chamber, an inlet device for introducing material to be processed into the inlet chamber, an outlet of the inlet chamber in the form an interruption or a passage in one of the partitions, the inlets and outlets for each of the Zwischenkamniern, wherein the outlet of each chamber horizontally and vertically in the waste ^■: stand is of the inlet of the chamber in question, and an outlet for withdrawal of processed material from the outlet chamber, with such an arrangement of the ⁰ "inlets and outlets that they cooperate to form a serpentine flow path for the flowing material being processed. Preferably, the partitions have good thermal conductivity.

Usually chemical processing is done with a sequence of processes or measures, e.g. successive ones Stages in a continuous chemical process, carried out in a series of vessels, which are passed through suitable flow devices, e.g. pipelines, Gutters and the like., Are connected to each other. As a container

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mostly cylindrical vessels were used; these have certain advantages in terms of simplicity and 7 / economy of manufacture and maintenance. But there are also square or rectangular containers used, for example, to make better use of the available floor space in systems, and for other reasons.

The use of separate containers to carry out a sequence of actions or operations instructs however, a number of inevitable disadvantages, since such Container normally through pipes or the like. need to be connected.

In an effort to eliminate the disadvantages associated with transferring material in a process of from one reaction zone to another, various proposals have been made. In some cases see this before the use of a single large container, for example of a rectangular overall shape, the is divided by inner partitions into a number of separate reaction chambers provided with stirring or agitation devices, the latter being designed in such a way that that the processing material passing through after a certain average residence time in each chamber over a overflow weir reaches the next chamber. Devices of this type are advantageous in some respects, but they also have a number of disadvantages. In particular they tend to be bypassed, i.e. a large bypass factor and thus an uneven distribution

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dwell time; this is due to the fact that an essential Proportion of material flowing into a given reaction chamber tends to be more or less horizontally transverse over the surface of the chamber contents and through the overflow weir = back out into the next chamber stream. Explained using the example of a phosphoric acid process, in the case of the phosphate rock, first leached with phosphoric acid to form monocalcium phosphate and the latter then with sulfuric acid to form a larger than the amount of phosphoric acid introduced into the leaching is converted, this large bypass factor leads to that neither of the two main reactions can be brought to an end in a single reaction zone. Rather, must at least one further leaching zone to prevent the reaction of phosphoric acid with phosphate rock, the in unreacted form from the initial leach zone is carried away to bring it to an end. Furthermore, at least one additional "reaction chamber" must be provided, to the reaction between sulfuric acid and calcium monophosphate, which in unreacted form from the initial "Reaction Chamber" is carried away to complete. It is common practice in phosphoric acid processes to carry out the reaction between sulfuric acid and calcium monophosphate in a plurality of reaction zones, the great bypass factor however, for a given mean residence time in a device of this type, results in one less full implementation than in other devices

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conventional type, y / as the arrangement of additional downstream Makes reaction zones necessary. In a typical device of this type it is common to at least to arrange eight or more successive chambers to leach the phosphate rock and implement the to bring the resulting calcium monophosphate to an end with sulfuric acid.

Another apparatus that has been disclosed and used for phosphoric acid processes and the like includes one outer container of approximately cylindrical shape, the inside by a cylindrical baffle into two compartments is divided into an annular and a central compartment.

When applied to the production of phosphoric acid rock, such an arrangement is usually used for the two-stage reaction of calcium phosphate rock with phosphoric acid and sulfuric acid in such a way that the two stages from (1) form a cycle through the circumference or hanging chamber and (2) consist of a stay in the small chamber, whereby the reaction mixture passes from the annular chamber into the medium chamber by means of an overflow weir. V / ith the material withdrawn from the fluid chamber through a bottom outlet and to the filter gelei- <A: t. Meco process management has also found a fairly broad definition and is in a range of points of view; primarily Indo adaptability in controlling the process

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of the reactions is to be mentioned. The flow behavior of the material in the annular chamber is in the absence of Emotion or movement more or less irregular and accidental. If, as is customary, stirring or moving devices are provided, a certain amount will be achieved Alignment of the flow behavior in the annular chamber, but it is still largely uneven and unregulated, which leads to the fact that certain proportions of the feedstock have a practically uninterrupted cycle through the Chamber in a much shorter than the mean residence time while performing other proportions of the feed in the stirrer flow path via the mean residence time be held and whirled around for much longer than a period of time. For the example of the production of phosphoric acid after the wet process usually occur through a Too long reaction time does not cause any major difficulties, but often due to incomplete conversion. Around a complete implementation of those parts of the feedstock that are in a way "short-circuited" ways flow, it is therefore necessary to increase the mean residence time of the feed as a whole, which of course leads to a reduction in the effective capacity and performance of a system or part of a system Size leads. In cases where σον / ohl a too lan ^ e as well as too short a message is not enough

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Difficulties intensified and. <ü; ilbiplisiert,, 30 da ^ they as a whole the application of a device of this type

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can look at all.

Another known device for carrying out the production of phosphoric acid and other processes has a reaction vessel with a central loading zone which is delimited by a suction pipe and the like; the The suction tube is located in a larger container that forms a reaction zone. In the usual embodiment of such a device, the central loading zone is provided with a stirring or agitation device, which is designed to move the feed mixture downwardly out of the feed zone and into the surrounding area Reaction zone pushes before any significant implementation takes place. Material is withdrawn from the reaction zone by means of an overflow weir and / or into the charging zone returned by flowing over the upper edge of the suction tube. The latter measure is with proceedings advantageous, in which considerable amounts of undesirable foam are generated, since the foam in the stirrer retrieved from the loading zone and broken open by the action of the stirrer or other movement device can be. Because of this feature, devices of this type have frequent manufacturing uses of phosphoric acid found by the so-called Kaß method, this process often involves difficulties due to excessive foaming. Devices of this While types are advantageous for their suds reducing properties, they display many of the above explained, with the use of the annular baffle

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or the container-in-container arrangement associated difficulties.JDer The invention has for its object to provide an apparatus for performing chemical processing of the To create the type outlined at the outset, which does not have the above-described and similar disadvantages of the known devices having. The essential features and technical advantages of the device according to the invention are evident from FIG The following explanation of preferred exemplary embodiments in conjunction with the attached drawings.

According to an advantageous embodiment includes the chemical processing device according to the invention in combination a container with internal partitions, the the container into a plurality of chambers including a first chamber, at least one intermediate chamber and subdivide an end chamber, a device for introducing material to be processed into the first chamber, Breaks or passages (interruptions) in the inner partitions to form an outlet for the first Chamber, an inlet and an outlet for each of the Intermediate chambers and an inlet for the end chamber, such that the outlet of each intermediate chamber is in located horizontally and vertically at a distance from the inlet of the chamber concerned, and a device for withdrawing processed material from the end chamber, the inlets and the outlets of the chambers are designed and arranged to cooperatively create a serpentine flow path from the feed point

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del · first chamber up to. the place of deduction of the processed Form material from the end chamber.

According to a preferred embodiment of the invention at least two of the chambers of the device are separated from one another by a heat-conducting partition, so that exothermic heat of reaction from one of the chambers to Heating of the material in the other of these chambers can be exploited.

According to another preferred embodiment, the means for introducing material into the first chamber a channel or! flow path, which is in Yv 'heat exchange relationship with at least one of the other chambers located so that exothermic heat of reaction from this other Lambs to preheat feed material on its way can be used to the first chamber.

In the normal design of the device according to the invention, the inner partitions are made of a flat one Material, e.g. flat metal sheets, smooth sheet metal or the like, or any other suitable acid and abrasion resistant thermally conductive material such as carbon Stand, manufactured.

The invention is made more preferred in the following Execution forms in connection with the attached Drawings further illustrated.

FIG. 1 shows an embodiment of the invention in which the processing zone is overflowed and underflowed Partition walls are divided into four compartments. The pre

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direction can be equipped according to further features of the invention with turbine stirrers and suction pipes.

FIG. 2 shows a section through the device according to FIG. 1 along line 2-2.

Figure 3 is a plan view of a device according to a modified embodiment of the invention.

FIG. 4- shows a vertical section along line 4-4 of FIG. 3.

FIG. 5 shows a plan view of a further embodiment according to the invention.

Figure 6 is a vertical section along line 6-6 of Figure 5.

Figure 7 shows details of a structural design of partitions with a flow channel.

In the embodiment according to FIG. 1, the Device a cylindrical outer wall 10 and a circular bottom 12, which together form a standing cylindrical Form container. The container is divided into four compartments by a pair of perpendicular intersecting compartments vertical partition walls, one of which as a partition 38 with a flow over it and the other as a partition with a flow below it 4-0 is trained. When operating such a device according to the invention, material to be processed is fed through a feed line 16 into the lower section of the first compartment. It then flows upwards in the first compartment and then over the Tx'enn-

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walled into the second compartment, as indicated by arrow 42 is. In the second compartment, the material flows downwards to a point level with the floor of the Compartment and then under the partition wall through into the third compartment, as indicated by the arrow 44.

In the third compartment, the material flows upwards to a point near the top of the container and then over the partition into the fourth compartment, as indicated by the arrow 46. In the fourth compartment the material flows in the downward direction and it is finally through an opening 48 in the lower section of this Compartment which is in communicating connection with a valve-controlled drainage extension (not shown), deducted. It will be understood that additional reactants will be introduced into any one or more of the four compartments can and that further extraction points for the withdrawal of material from the process before the passage through all four Compartments can be provided for cases in which not all four compartments are to be carried out in the individual case Treatment are required.

In the embodiment shown in Figures 1 and 2, motor-driven movement devices, e.g. stirrer 50, and in three of the compartments the shafts of stirrers 50 are surrounded by suction pipes 52. The order of stirrers, possibly with suction pipes, is not absolutely necessary and it can also, depending on the location of the If so, with a device according to FIGS. 1 and 2

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work without the stirrer and / or suction tubes. When using the suction pipes, these can be provided with slots or openings be provided, such as through the slots 54 and 56 is indicated in order to influence the flow path of the material through the compartment during the process, for example when using stirrers with turbine wheels or propellers, as is preferred, the material of the Propeller is pushed radially outward and the material flowing to the propeller is axially out of the area above and below sucked in by the propeller. In the device shown in Figure 1, the total movement of the material takes place in the

Compartment with the suction tube 52 in the downward direction and a Slot 54- near the surface of the material creates a Sucking in surface foam, whereupon it flows to the propeller, where it is quickly broken up and destroyed. This is particularly advantageous for phosphoric acid and similar processes where foaming is sometimes a major issue Problem.

Figures 1 and 2 also show a preferred structural design, which under corrosive conditions or The presence of abrasive substances can be used; this is the leaching and conversion of phosphate rock with sulfuric acid a typical example. In this preferred embodiment, the cylindrical outer wall is made of a u Corrosion and abrasion resistant material 58, e.g. neoprene or the like, with a cylindrical jacket 60 lying around it

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Steel or any other structurally strong material. The bottom of the container is made of the same corrosion and abrasion resistant material 58 and it can also be supported by an external structural jacket or directly on the floor of the building rest. The overflow and / or underflow. Partition walls 38 and 40 can also be used in the same or a similar manner Or they can be made of steel sheets and the like. Made with a corrosion and abrasion resistant material are coated exist.

FIGS. 3 and 4 illustrate another embodiment of the device according to the invention, which is similar to the embodiment according to FIGS has a cylindrical shape and the other three are formed by portions of a hanging rim which surrounds the central cylindrical chamber. As can be seen from FIG. 3, the initial chamber has a cylindrical shape and is delimited by a substantially cylindrical partition wall Ck 'which is arranged concentrically with the outer container wall 10 and extends downwards to the bottom 12 of the outer container.

The annular space between the cylindrical partition wall 62 and the outer wall 10 of the device is through f '.' iaialo partitions 64, 66 and 63 in three chambers 70 »72 and

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74- divided. An overflow channel 76 or the like. near the Partition wall 64- ensures a flow of material into your process from the chamber 78, i.e. that through the cylindrical partition 62 limited chamber, into chamber 70, which is controlled by the Partition 62, the radial partition walls 64 and 66 and the · outer wall 10 is limited.

The partition 66 ends shortly before the floor 12 (or is in the vicinity of an underflow weir or an opening the bottom of the partition) to allow a flow of material from the bottom of chamber 70 to the bottom of chamber 72 bring about. The chamber 72 is defined by the cylindrical partition 62, the outer wall 10 and the radial partition walls 66 and 63 limited.

The radial partition wall 68 ends just below the level of the outer wall 10 and the cylindrical partition wall 62 (or they is provided with an overflow weir or an opening near its top), so that in the process an overflow of Material enters from the head of chamber 72 to the head of chamber 74-.

The chamber 74 is delimited by the cylindrical partition wall 62, the outer wall 10 and the radial partition walls 68 and 64. During operation, material is extracted from the chamber ^; 74- withdrawn through a suitable outlet in the bottom area, indicated by SO, in the vicinity of the partition wall 64-. '

From the above explanation it can be seen that the device as a whole is designed so that the Vex'-drive flowing material is forced to

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clien serpentine, alternating upwards and downwards To follow the flow path, i.e. to the bottom of the chamber through a suitable bottom inlet (not shown), up through chamber 78 and through the overflow chute into chamber 70 »down in chamber 70 and below Partition 66 through to the bottom of chamber 72, upward in the chamber 72 and across the partition 68 into the chamber 74 · and then down in the chamber 74- to the bottom outlet 80. The Flow in this way can, and is preferably, supported and / or modified by using more suitable methods Agitation or agitation means 82 in the various chambers. The stirring or agitation devices 82 are not absolutely necessary, but they support the maintenance of a homogeneous reaction mixture and the Avoidance of any tendency for the material to form layers and thus promote complete and rapid conversion by ensuring that the components are thoroughly mixed. However, it can be seen that with but also without the stirring or agitation means 82, any tendency for the material flowing in the process to bypass or abbreviation of the prescribed flow path, i.e. "a "Short circuit", by the way in which the inlet of each chamber is both vertical and horizontal Direction spaced from the outlet of the chamber in question is avoided; so it is not a "Short-circuit path" present on the material in the short circuit flow and in a much lower than the middle

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Dwell time could get from the inlet to the outlet.

When using the device according to FIGS. 3 and 4 for the production of phosphoric acid by the hate process Ground phosphate rock and recycled phosphoric acid are fed at the bottom of chamber 78. The leaching reaction between these reaction materials by which the PpO ^ fractions of the phosphate rock in monocalcium phosphate are converted, takes place in the chamber 78 and runs there substantially / to the end. That digested Mixture consisting mainly of a pulp of calcium monophosphate in excess aqueous phosphoric acid exists, flows through the channel 76 into the chamber 70 above. The head of the chamber 70 is sulfuric acid in any one in a suitable manner, e.g. by feeding together with the material overflowing from the chamber 75 into one of the stirring or agitation devices 82. The sulfuric acid reacts with the LIonocaLc iumpho sphat under Formation of phosphoric acid and calcium sulphate.

The total amount of sulfuric acid that is required for the reaction with the monocalcium phosphate is preferably not used is added in chamber 70. Rather, a limited amount of sulfuric acid is expediently used Generation of crystal nuclei of the desired kind is regulated, first added and the rest of the sulfuric acid is added then added in one or more separate stages in subsequent reaction zones. When using the Device according to Figures 3 and 4 for implementation

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such a procedure becomes a limited proportion the necessary to react with the monocalcium phosphate ocliv / ef el acid added to the chamber 70 and this reacts there with the formation of phosphoric acid and calcium sulfate from part of the Ilonocalciumsttteateat. The resulting reaction slurry after passing through the chamber 70 flows under the partition 66 into the chamber 72. The in this way below The pulp flowing through it consists mainly of an aqueous mixture of calcium monophosphate, phosphoric acid and G alc iumpho sphat.

The further sulfuric acid, which is necessary for the reaction with the remaining monocalcium phosphate in the slurry introduced into the chamber 72, can be ^{fed completely into the chamber 72 or partly into the chamber 72 and partly into the chamber 7 z} t-. In any case there flows ?; in processing material located from the bottom of the chamber 72 in liähe the! partition wall through the chamber 72 to pass to its upper end in the partition wall 68. Then, it flows 66 via the Trennv / and 68 in the chamber 7 ¹ V ₁ through this chamber 74 through to the bottom outlet 80 near the partition wall 64 and then it is withdrawn through the outlet 80.

It can be seen that the central Laugungskammer 7 ^r - which heats when used in a method derarbigen v / er'io / i must, in order to bring the phosphoric acid and Phosphabgestein CuX iieaktionntemperatur, vb'llig or partially '/ on chambers surrounded in which an exothermic reaction zv / Irjchen, '"jchv / el'elKäurfc and MoiiooalciUiiiphorjphab takes place.

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according to the exothermic heat of reaction, which in the chambers 70 and 72 and optionally also in the chamber 74- (depending on the work and manner in which the process is operated) is transferred through the partition wall 62 into the chamber 78 and thus provides the necessary heat for heating the reactants to the reaction temperature. It is readily apparent that the applicability of the device is not limited to this particular process, but rather to any continuous chemical process of this type extends, in which heat from a reaction stage is expedient to increase the temperature of the reactants in another, either preceding or succeeding Reaction stage can be exploited.

Figures 5 and 6 illustrate another Embodiment according to the invention. In this embodiment, the outer wall 10 of the container is not cylindrical but rectangular. The space within the container wall 10 is divided into four chambers by suitable partition walls

mern 83 _} 84, 86 and 88 divided. The reactants are introduced into the chamber 83, flow from the chamber 83 under the corresponding partition wall into the chamber 84, then from the chamber 84 over the corresponding partition wall into the chamber 86, then from the chamber 86 again under the corresponding partition wall into the Chamber 88, whereupon it is finally removed from the head of chamber 88 by a suitable device, κ. B ο an overflow channel ο the like., Be pulled off.

At least one of the real-life participants : ± vd In

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the chamber 33 is introduced by way of at least one of two preheating channels. A channel 90 runs between the chambers 84 and 86 and a channel 92 extends between them Chambers 36 and 88. Both channels 90 and 92 unite in a channel 94- which runs between chambers 83 and 84 and opens into chamber 83. It can be seen that feedstock that enters the chamber 83 through the channel 94 and is introduced into the channel 90 or 92, in heat exchange relation with at least two of the chambers 84, 86 and 88 flows in.

When using the device described above for the production of phosphoric acid according to the ITass process, the chamber 83 for the leaching stage, ie the reaction between phosphoric acid and ground phosphate rock to produce monocalcium phosphate, and the chambers 84, 36 and 88 for the reaction of sulfuric acid with the monocalcium phosphate produced in the leaching step can be used. When the device is used in this way, the mixture in the chamber 83 must be heated to the reaction temperature. Sufficient exothermic heat of reaction is available for this from the reactions which take place in chambers 84, 86 and (if used) chamber 88. When using the device according to FIGS. 5 and 6 in such a method, the phosphoric acid or a slurry of phosphate rock in phosphoric acid can be introduced into the chamber 83 via the channel 90 and / or the channel 92, both of which open into the channel 94. earth. When I ¹ IuB through these channels, the

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Phosphoric acid or the porridge by touching the walls of chambers 84-, 86 and 88 preheated to reaction temperature, these walls in turn due to the exothermic heat of the reaction between sulfuric acid and monocalcium phosphate, which takes place in these chambers, are heated.

FIG. 7 shows, on the basis of a section along line 7-7 of FIG. 5, an advantageous design of the partition between the chambers 83 and 84 (which can be used in the same way for the other partition walls). The floor has a projecting base 98 which is lined with two layers 58 and 59 of materials having properties suitable for the process to be carried out. On the base there are parts 100 which form the channel 94 between them.

It is readily apparent that the device according to the invention, because of its particular suitability for the production of phosphoric acid according to the liaß process has been explained above in particular in connection with this mode of operation, does not apply to this particular method is limited but is used in a corresponding manner in many other chemical processing methods can, especially those in which one of a number of successive processing stages exothermic heat of reaction generated, which is advantageous in another stage of the process for heating the reactants to a desired reaction temperature can be exploited. The device according to the invention is also particular

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useful for performing chemical processes with successive processing stages in which there is What is important is the "residence time of the reactants in of a given processing zone before transitioning to the to stabilize the subsequent processing zone and evenly to make, of course, the device can also with procedural measures without actual chemical reaction, e.g. for dissolving processes and the like.

The device according to the invention is preferred above for explanation in connection with the drawings with reference to Embodiments have been illustrated, but it can be seen that according to the individual case, appropriate changes or modifications made or corresponding equivalents can be used without departing from the scope of the invention.

Claims (6)

Claims 1. Apparatus for performing chemical processing or the like. Which in combination a container, inner partition walls, which subdivide the container into a plurality of Kanbmern with a first chamber, at least one intermediate chamber and an end chamber, a device for the introduction of to be processed Material in the first chamber and a device for the withdrawal of processed material from the end chamber, characterized in that the inner (partitions (38, 40; 62, 64, 66, 68; 98, 1.00) have interruptions or passages, which are arranged to have an outlet for the first chamber. (e.g. 78 or 8J), an inlet and an outlet for each of the intermediate chambers (e.g. 70, 72 or 84, 86) and an inlet for the end chamber (e.g. 74 or 88) form, the outlet -. · .- - <- of each intermediate chamber is "in the horizontal and vertical direction at a distance from the inlet of the relevant chamber, and the inlets and outlets of the chambers together n a serpentine flow path from the inlet of the. ;, ■ ^ first chamber to the point where the processed material is drawn off from the end chamber. 2. Apparatus according to claim 1, characterized in that at least two of the chambers by a heat 109824/1418 conductive partition, so that generated in one of the chambers Heat can be used to heat the contents of another of the chambers, are separated from one another. 3 · Device according to claim 1 or 2, characterized in that the device for introducing Material into the first chamber (e.g. 83) is in heat exchange relationship with at least one other of the chambers arranged inflow or channel (90 * 92, 94 ·) »so that in this Chamber generated heat for preheating of feedstock on the way to the grounding chamber can be used. 4-. Device according to one of claims 1-3 » characterized in that at least one of the chambers is provided with a stirring or agitation device (50; 82) which is a Has impeller or a propeller in the manner of a turbine, is provided. 5 · Device according to one of claims 1-4 ·, characterized characterized in that at least one of the chambers with a guiding or moving device (50; 82) and a die Stirring or moving device surrounding suction pipe (52) ▼ can be seen. 6. Apparatus according to claim 5 »characterized in that the suction pipe (52) extending approximately horizontally Has slots (5 ^, 56). 10982A / U18