Method and Fluidization Apparatus Unit for Treating a Large Number of Batches of a Material Having a Moisture Content

Abstract

A method and a fluidization apparatus unit for treating a large number of batches of a material having a moisture content and having a material temperature. The fluidization apparatus unit includes a fluidization apparatus. The fluidization apparatus has a fluidization chamber which has a material inlet and a material outlet, and also includes a fluid inlet and a fluid outlet for a drying gas which fluidizes the material in the fluidization chamber and which has a drying gas moisture content.

Claims

1. A method for treating a large number of batches of a material having a moisture content and a material temperature in a fluidization apparatus unit comprising a fluidization apparatus, wherein the fluidization apparatus of the fluidization apparatus unit has a fluidization chamber which has a material inlet and a material outlet, and which also comprises a fluid inlet and a fluid outlet for a drying gas which fluidizes the material in the fluidization chamber and which has a drying gas moisture content, the method comprising: during the treatment of the material of a batch in the fluidization apparatus in a first treatment period, at least part of a liquid which constitutes the moisture content in the material of the material of the batch introduced into the fluidization chamber is evaporated by a supplied heat provided by means of the drying gas, such that the material of the batch cools down from an initial material temperature to a material minimum temperature as a result of an associated removal of evaporation heat; and in a second treatment period, liquid is further evaporated by the supplied heat provided by means of the drying gas, such that the material of the batch heats up to a material end temperature, and consequently the moisture content of the material of the batch is reduced to a residual moisture content during the treatment, wherein the material end temperature is found as the sum of the individual material minimum temperature for the material of a batch and a prespecified increase temperature that is the same for each batch of the material.

2. The method according to claim 1, wherein the increase temperature is determined in a reference measurement, wherein the increase temperature corresponding to a temperature difference between the material minimum temperature of the material treated in the reference measurement and the material end temperature of the material treated in the reference measurement.

3. The method according to claim 2, wherein the treatment of a first batch of material of a large number of batches of the material in the fluidization apparatus serves as a reference measurement.

4. The method according to claim 2, wherein the reference measurement is carried out before the treatment of a large number of batches of a material in the fluidization apparatus, as a separate treatment of the same material.

5. The method according to claim 1, wherein the increase temperature is determined from a database before the treatment of a large number of batches of a material in the fluidization apparatus.

6. The method according to claim 1, wherein the material to be treated is produced in a granulating device arranged upstream of the fluidization apparatus, and is then fed to the fluidization apparatus.

7. The method according to claim 1, wherein the material minimum temperature is found as the mean value of the material temperature in a time interval.

8. The method according to claim 7, wherein the time interval begins when the material minimum temperature is reached.

9. The method according to claim 7, wherein, for calculating the material minimum temperature in the form of the mean value of the material temperature in the time interval, the lowest material temperature in this time interval is weighted more heavily.

10. The method according to claim 1, wherein the material minimum temperature is found as the mean value of the material temperature in a temperature interval.

11. The method according to claim 10, wherein, for calculating the material minimum temperature in the form of the mean value of the material temperature in the temperature interval, the lowest material temperature is weighted more heavily in this temperature interval.

12. The method according to claim 1, wherein the fluidization apparatus has a spray device which sprays the material of a batch with a liquid at least at times during the treatment.

13. The method according to claim 1, wherein the treatment of a batch of the material in the fluidization apparatus unit comprising the fluidization apparatus is stopped after the material end temperature has been reached.

14. A fluidization apparatus unit for treating a large number of batches of a material having a moisture content and a material temperature, with a fluidization apparatus and a control device, wherein the fluidization apparatus has a fluidization chamber which has a material inlet and a material outlet, which also comprises a fluid inlet and a fluid outlet for a drying gas which fluidizes the material in the fluidization chamber and which has a drying gas moisture content, wherein, during the treatment of the material of a batch in the fluidization apparatus in a first treatment period, at least part of a liquid which constitutes the moisture content in the material of the material of the batch introduced into the fluidization chamber is evaporated by a supplied heat provided by means of the drying gas, such that the material of the batch cools down from an initial material temperature to a material minimum temperature as a result of an associated removal of evaporation heat and, in a second treatment period, liquid is further evaporated by the supplied heat provided by means of the drying gas, such that the material of the batch heats up to a material end temperature, and consequently the moisture content of the material of the batch is reduced to a residual moisture content during the treatment, wherein the control device comprises a temperature measuring device suitable for detecting the material minimum temperature, and an evaluation device suitable for finding the material end temperature as the sum of the individual material minimum temperature for the material of a batch and an increase temperature which is prespecified in the evaluation device and is the same for each batch of the material.

15. The fluidization apparatus unit according to claim 14, wherein the temperature measuring device has a thermocouple arranged in the fluidization chamber of the fluidization apparatus.

16. The fluidization apparatus unit according to claim 14, wherein the temperature measuring device and evaluation device form a structural unit.

17. The fluidization apparatus unit according to claim 14, wherein the fluidization apparatus is designed as a fluidized bed or spouted bed apparatus.

18. The fluidization apparatus unit according to claim 14, wherein the fluidization apparatus has a spray device for a liquid to be applied to the material to be treated.

19. The method according to claim 10, wherein the material minimum temperature is found as the mean value of the material temperature in a temperature interval of .sub.+5° C. around the lowest material temperature.

20. The method according to claim 10, wherein the material minimum temperature is found as the mean value of the material temperature in a temperature interval of .sub.+3° C. around the lowest material temperature.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The invention is explained in more detail below with reference to the attached drawings.

[0025] FIG. 1 is a schematic illustration of a first embodiment of a preferred fluidization apparatus unit for treating a large number of batches of a material having a moisture content, with a fluidization apparatus and a control device,

[0026] FIG. 2 is a schematic illustration of a basic profile of both the material temperature and the process end temperature shown plotted over time, during the treatment of a batch of material in a fluidization apparatus of a fluidization apparatus unit,

[0027] FIG. 3 is a table with the experimentally determined measurement data of Test 1, for the conventional treatment of a batch of a material having a moisture content and having a material temperature with a fluidization apparatus of a fluidization apparatus unit,

[0028] FIG. 4 is a table with the experimentally determined measurement data of Test 2, for the conventional treatment of a batch of a material having a moisture content and having a material temperature with a fluidization apparatus of a fluidization apparatus unit,

[0029] FIG. 5 is a diagram with the profile of the material temperature of Tests 1 and 2 and the process end temperature, plotted over time.

[0030] FIG. 6 is a table with the experimentally determined measurement data of Test 3, for the conventional treatment of a batch of a material having a moisture content and having a material temperature with a fluidization apparatus of a fluidization apparatus unit,

[0031] FIG. 7 is a table with the experimentally determined measurement data of Test 4, for the conventional treatment of a batch of a material having a moisture content and having a material temperature with a fluidization apparatus of a fluidization apparatus unit,

[0032] FIG. 8 is a diagram with the profile of the material temperature of Tests 3 and 4 and the process end temperature, plotted over time,

[0033] FIG. 9 is a table with the experimentally determined measurement data of Test 5, for the treatment of a batch of a material having a moisture content and having a material temperature with a fluidization apparatus of a fluidization apparatus unit according to the preferred method,

[0034] FIG. 10 is a table with the experimentally determined measurement data of Test 6, for the treatment of a batch of a material having a moisture content and having a material temperature with a fluidization apparatus of a fluidization apparatus unit according to the preferred method,

[0035] FIG. 11 is a diagram with the profile of the material temperature of Tests 5 and 6 and the process end temperature, plotted over time.

[0036] FIG. 12 is a table with the experimentally determined measurement data of Test 7, for the treatment of a batch of a material having a moisture content and having a material temperature with a fluidization apparatus of a fluidization apparatus unit according to the preferred method,

[0037] FIG. 13 is a table with the experimentally determined measurement data of Test 8, for the treatment of a batch of a material having a moisture content and having a material temperature with a fluidization apparatus of a fluidization apparatus unit according to the preferred method, and

[0038] FIG. 14 is a diagram with the profile of the material temperature of Tests 7 and 8 and the process end temperature, plotted over time.

DETAILED DESCRIPTION

[0039] Unless otherwise specified, the following description relates to all of the embodiments illustrated in the drawings of a fluidization apparatus unit 2 that is suitable for treating a material G and that comprises a fluidization apparatus 1.

[0040] FIG. 1 is a schematic illustration of a first embodiment of the preferred fluidization apparatus unit 2. The fluidization apparatus unit 2 is suitable for treating a large number of batches of a material G having a moisture content f.sub.G and a material temperature T.sub.G, and has a fluidization apparatus 1 and a control device 3.

[0041] In the embodiment shown, the fluidization apparatus 1 is designed as a spouted bed apparatus 4. The structure of the spouted bed apparatus 4 comprises, from bottom to top, a distribution chamber 5, a fluidization chamber 6, an expansion zone 7 and an exhaust air part 8.

[0042] In an embodiment that is not shown, the fluidization apparatus 1 of the fluidization apparatus unit 2 is designed, for example, as a fluidized bed apparatus or as a fluidized bed granulator.

[0043] The fluidization chamber 6 of the fluidization apparatus 1 of the fluidization apparatus unit 2 has a material inlet 9 and a material outlet 10. The fluidization chamber 6 also has a fluid inlet 11 and a fluid outlet 12 for a drying gas TG which fluidizes the material G in the fluidization chamber 6 and which has a drying gas moisture content f.sub.TG.

[0044] The drying gas TG required for drying the material G to be treated in the fluidization apparatus 1 is supplied to the distribution chamber 5, where the drying gas TG enters in distributed form via the fluid inlet 11, which has a gap opening 13 and a drying gas deflection part 14, into the fluidization chamber 6, preferably as a type of free jet. Furthermore, the cross-section of the fluidization apparatus can optionally increase in the expansion zone 7, as shown in FIG. 1, such that the speed of the flow of drying gas in the fluidization apparatus 1 continuously decreases toward the top. The drying gas TG leaves the spouted bed apparatus 4 preferably in the exhaust air part 8 as cleaned exhaust gas A, wherein a deducting system 15, in particular filter cartridges or textile filter elements, is formed in the exhaust air part 8. In the embodiment shown, the fluidization chamber 6 of the fluidization apparatus 1 is supplied via the material inlet 9 with the material G, which has a moisture content f.sub.G and a material temperature T.sub.G, from a granulating device 16 arranged upstream of the fluidization apparatus 1. The granulating device 16 is preferably designed as an extruder, or as a high-shear granulator.

[0045] In the fluidization chamber 6, the material G is entrained upwards in the direction of the de-dusting system 15 by the drying gas TG. The drying gas velocity v.sub.TG decreases in the upper region of the fluidization chamber 6 and in the expansion zone 7 above it, such that the material G flowing upwards can emerge laterally out of the flow of drying gas and fall back into the fluidization chamber 6. The fluidization chamber 6 is delimited in the lower region by inclined lateral surfaces 17. Due to the inclined lateral surfaces 17, the material G is conveyed by the effect of gravity via the return zone 18 in the direction of the fluid inlet 11 designed as a gap opening 13, where the material G is then entrained again by the drying gas TG into the fluidization chamber 6.

[0046] A very uniform circulation 19 of the material G is formed by this mechanism, which circulation promotes an almost ideal mixing of the material G. One or more spray devices 20, preferably a spray nozzle or the like, can be or are arranged in the lower region of the fluidization chamber 6 and spray upwards in the same direction as the drying gas TG, serving to introduce an optionally additional liquid F. Such an introduction of the liquid F in the lower region of the fluidization chamber 6 is referred to as a bottom spray.

[0047] The spray device 20, preferably a two-component nozzle, is configured to spray droplets with a droplet size of less than 0.5 μm to 200 μm, preferably from 10 μm to 100 μm, particularly preferably between 20 μm and 60 μm. Very particularly preferably, the sprayed droplets have a droplet size of 25 μm to 40 μm, most preferably 30 μm.

[0048] By adjusting the droplet size by means of the spray device 20 and the compressed air applied to the spray device 20, the shearing forces occurring during spraying can be set precisely, such that a very homogeneous droplet size of the liquid F to be sprayed—expediently, a suspension or an emulsion—can be achieved and/or reached. The droplets accumulate on the material G, and film evaporation of the liquid F and the moisture content f.sub.G of the material G preferably takes place in the drying gas flow.

[0049] Due to the very advantageous heat and mass transfer and the high circulation 19 of the material G in the spraying area 21 of the fluidization chamber 6 of the spouted bed apparatus 4, the liquid F is largely deposited on the material G, which is accordingly uniformly wetted on the material surfaces. The uniform wetting with a simultaneous high circulation 19 of the material G between the spraying area 21 and the return zone 18 causes a very uniform liquid film to be formed on the material G. Because of the drying process, the liquid F, and also a quantity of the liquid F in the material G (moisture content f.sub.G) evaporate and leave the spouted bed apparatus 4 with the exhaust gas A.

[0050] The treated material G is discharged from the fluidization apparatus 1 via the material outlet 10, which can expediently be embodied as an overflow or as a volumetric discharge element, in particular a rotary valve, or also as a gravity classifier, preferably a zigzag classifier subjected to classifying gas, or a riser tube classifier.

[0051] Mechanical units 23, such as shredders, choppers, etc., can be arranged as required in the fluidization chamber 6, preferably in the return zone 18, in order to produce sufficiently fine material G by comminution.

[0052] One or more spray devices 23 can optionally be arranged in the fluidization chamber 6 or in the apparatus parts lying above it, the expansion zone 7 and the exhaust air part 8, which preferably spray downwards (top spray). The liquid F can likewise be injected into the fluidization chamber 6 of the spouted bed apparatus 4 via the spray device 23. Alternatively, additives or other components can be sprayed in liquid form via some of the spray devices 20, 23, and thus embedded homogeneously in the material G.

[0053] In a further embodiment that is not shown, the spray devices 20, 23 can be arranged in their position in the fluidization chamber 6, in particular also on the lateral surfaces 17.

[0054] The control device 3 comprises a temperature measuring device 25 having a thermocouple 24 so for detecting the material temperature T.sub.G and an evaluation device 26 for determining the material minimum temperature T.sub.G, . . . , min from the material temperature T.sub.G, . . . during the treatment of the material G of the batch. The temperature measuring device 25 and the evaluation device 26 expediently form a structural unit 27.

[0055] The thermocouple 24 is arranged in the fluidization chamber 6 of the fluidization apparatus 1. The temperature T in the fluidization chamber 6, which substantially corresponds to the material temperature T.sub.G, . . . due to the almost ideal mixing of the material G to be treated in the fluidization chamber 6, can be detected as the material temperature T.sub.G, . . . by means of the thermocouple 24.

[0056] The material temperature can be relayed from the thermocouple 24 of the temperature device 25 to the evaluation device 26 of the control device 3 via communication means 30, and can be stored in storage means 28 of the control device 3. The evaluation device 26 is expediently suitable for evaluating the material temperature T.sub.G, . . . in relation to a material minimum temperature T.sub.G, . . . , min, and storing the material minimum temperature T.sub.G, . . . , min in the storage means 28.

[0057] In addition, the evaluation device 26 is suitable for storing an increase temperature T.sub.+ that is the same for each batch of the material G. The increase temperature T.sub.+ can be determined in different ways, preferably by a reference measurement.

[0058] The evaluation device 26 is also suitable for calculating a material end temperature T.sub.G, . . . , E as the sum of the individual material minimum temperature T.sub.G, . . . , min for the material G of a batch and an increase temperature T.sub.+ specified in the evaluation device 26, which is the same for each batch of the material G.

[0059] A database 29 for storing the increase temperatures is also connected to the control device 3, for example, via communication means 30.

[0060] FIG. 2 is a schematic illustration of a basic profile of both the material temperature T.sub.G and the process end temperature T.sub.E shown plotted over the treatment time t, during the treatment of a batch of material G in a fluidization apparatus 1 of a fluidization apparatus unit 2 described as an example in FIG. 1. The material temperature T.sub.G is given in the unit “° C.”, and the time in the unit “minutes”. The material end temperature T.sub.G, . . . , E constitutes the process end temperature T.sub.E.

[0061] The treatment time t for drying the material G is divided into two treatment periods I and II.

[0062] In treatment period I, during the treatment of the material G of a batch in the fluidization apparatus 1, at least part of a liquid F.sub.G that constitutes the moisture content f.sub.G in the material G of the batch introduced into the fluidization chamber 6 evaporates as a result of the supplied heat Q introduced by means of the drying gas TG, such that the material G of the batch cools down from an initial material temperature T.sub.G, . . . , A to a material minimum temperature T.sub.G, . . . , min because of the associated removal of evaporation heat ΔQ.sub.v.

[0063] The material minimum temperature T.sub.G, . . . , min can be found, for example, as the minimum value of the material temperature T.sub.G, . . . in the processing period I or as the mean value of the material temperature T.sub.G, . . . in a time interval Δt. In this case, the time interval Δt expediently begins when the material minimum temperature T.sub.G, . . . , min is reached. for calculating the material minimum temperature T.sub.G, . . . , min in the form of the mean value of the material temperature T.sub.G, . . . in a time interval Δt, the lowest material temperature T.sub.G, . . . , Δt is weighted more heavily, preferably dou-r ble.

[0064] Alternatively, the material minimum temperature T.sub.G, . . . , min can be found as the mean value of the material temperature T.sub.G, . . . in a temperature interval ΔT, preferably in a temperature interval ΔT of .sub.+5° C. around the lowest material temperature T.sub.G, . . . , more preferably in a temperature interval ΔT of .sub.+3° C. around the lowest material temperature T.sub.G, . . . . In this case, too, there is the possibility when calculating the material minimum temperature T.sub.G, . . . , min in the form of the mean value of the material temperature T.sub.G, . . . in a specific temperature interval ΔT to weight the lowest material temperature T.sub.G, . . . more heavily, preferably double.

[0065] In a treatment period II, further liquid F.sub.G is evaporated by the supplied heat Q provided by means of the drying gas TG, such that the material G of the batch heats up to a material end temperature T.sub.G, . . . , E, and the moisture content f.sub.G, . . . of the material G of the batch is reduced to a residual moisture content f.sub.G, . . . , R during treatment. When the material end temperature T.sub.G, . . . , E is reached, the drying process is stopped, the treated material G is discharged from the fluidization apparatus 1 and is optionally sent for further treatment.

[0066] The material end temperature T.sub.G, . . . , E is found as the sum of the individual material minimum temperature T.sub.G, . . . , min for the material G of a batch and a prespecified increase temperature T.sub.+ which is the same for each batch of the material G. The material minimum temperature T.sub.G, . . . , min depends, among other things, on the amount of liquid F.sub.G in the material G and the drying gas moisture content f.sub.TG.

[0067] The increase temperature T.sub.+ is expediently determined in a reference measurement, wherein the increase temperature T.sub.+ corresponds to a temperature difference between the material minimum temperature T.sub.G, . . . , min of the material G treated in the reference measurement and the material end temperature T.sub.G, . . . , E of the material G treated in the reference measurement.

[0068] The treatment of the first batch of the material G of a large number of batches of a material G then preferably serves as a reference measurement, or a separate treatment of the same material Gas in the later treatment of the batches of the material G is used as a reference measurement before the treatment of a large number of batches of the material G in a fluidization apparatus 1. In addition, there is the possibility of determining the increase temperature T.sub.+ before the treatment of a large number of batches of a material G in a fluidization apparatus 1 from a database.

[0069] Tests 1 to 8, the measurement data for which are shown in tables and diagrams in FIGS. 3 to 14, were carried out with the following test equipment:

[0070] In the tables in FIGS. 3, 4, 6, 7, 9, 10, 12 and 13, the letter S denotes the target value and the letter I denotes the actual value measured in the corresponding test.

[0071] In Tests 1 (V.sub.1) to 8 (V.sub.8), the material G formed as wet granules was produced from a mixture of four different granulation materials, specifically 1.276 g lactose, 648 g microcrystalline cellulose (MCC), 61 g polyvinylpyrrolidone (PVP 30) and 40 g of talc, and 475 g of water as the granulating liquid, in the granulating device 16—a twin-screw extruder of the type Pharma 16 from Thermo Scientific™, with a throughput of 5 kg/h—and then introduced in batches into the fluidization apparatus 1 of the type GPCG 2 LabSystem from Glatt GmbH for treatment, in particular for drying. Textile filter elements T165P with filter openings of 20 μm were used as the deducting system 15 in the fluidization apparatus 1.

[0072] In the Tests 1 (V.sub.1) to 4 (V.sub.4), the conventional method according to the prior art for drying the material G was used, in which the material end temperature T.sub.G, . . . , E was set to a fixed temperature value in advance, i.e., before the start of the test.

[0073] The process end temperature T.sub.E, . . . was set at 42.1° C. for Tests 1 (V.sub.1) to 4 (V.sub.4) respectively, i.e., the treatment of the respective material G in the fluidization chamber 6 of the fluidization apparatus 1 was stopped when a material end temperature T.sub.G, . . . , E of 42.1° C. was reached.

[0074] The tests 1 (V.sub.1) and 2 (V.sub.2) as well as Tests 3 (V.sub.3) and 4 (V.sub.4) are regarded as respective batches of the same material G.

[0075] In all of Tests 1 (V.sub.1) to 4 (V.sub.4), the drying gas temperature T.sub.TG, . . . , FE which was pre-set for each of Tests 1 (V.sub.1) to 4 (V.sub.4), the drying gas moisture content f.sub.T, . . . , FE, and the drying gas volume flow V.sub.TG, . . . , FE at the fluid inlet 11 of the fluidization apparatus 1 were kept constant over the treatment time t.

[0076] The table shown in FIG. 3 shows measurement data from Test 1 (V.sub.1), in which the fluidization chamber 6 of the fluidization apparatus 1 has already been preconditioned at the fluid inlet 11 with a drying gas TG that has a drying gas temperature T.sub.TG,V1,FE of 60° C., a drying gas moisture content f.sub.TG,V1,FE of 7.6 g/kg, and a drying gas volume flow V.sub.TG,V1,FE of 70 m.sup.3/h.

[0077] FIG. 4 shows a table of measurement data for Test 2 (V.sub.2), in which the fluidization chamber 6 of the fluidization apparatus 1 was preconditioned at the fluid inlet 11 with a drying gas TG which has a drying gas temperature T.sub.TG,V2,FE of 60° C., a drying gas moisture content f.sub.TG,V2,FE of 19.5 g/kg, and a drying gas volume flow V.sub.TG,V2,FE of 70 m.sup.3/h.

[0078] As such, Tests 1 (V.sub.1) and 2 (V.sub.2) differed only in the drying gas moisture content f.sub.TG, . . . , FE of the drying gas TG.

[0079] The diagram shown in FIG. 5 shows the material temperature T.sub.G, . . . during the treatment of the material G of a batch in the fluidization apparatus 1 of the fluidization apparatus unit 2 for Tests 1 (V.sub.1) and 2 (V.sub.2).

[0080] As already explained in FIG. 2, during the treatment of the material G of a batch in the fluidization apparatus 1 in a first treatment period I, at least part of a liquid F.sub.G which constitutes the moisture content f.sub.G, . . . in the material G evaporates from the material G of the batch introduced into the fluidization chamber 6 as the result of the supplied heat Q provided by means of the drying gas TG, such that the material G of the batch cools down from an initial material temperature T.sub.G, . . . , A to a material minimum temperature T.sub.G, . . . , min because of an associated removal of evaporation heat ΔQ.sub.V.

[0081] In a second treatment period II, liquid F.sub.G continues to evaporate due to the supplied heat Q provided by the drying gas TG, such that the material G of the batch heats up to a material end temperature T.sub.G, . . . , E, and the moisture content f.sub.G, . . . of the material G of the batch is reduced to a residual moisture content f.sub.G, . . . , R during the treatment.

[0082] In Test 1 (V.sub.1), the material temperature T.sub.G,V1 falls during the treatment of the material G in the first treatment period I, which lasts 20 minutes, from an initial material temperature T.sub.G,V1,A of 32.1° C. to a material temperature T.sub.G,V1 of 26.1° C., wherein the material minimum temperature T.sub.G,V1,min of 24.0° C. is reached after 5 minutes in the first treatment period I. In the second treatment period II, which lasts 22 minutes, the material G is then heated to the material end temperature T.sub.G,V1,E of 42.1° C.; when this temperature is reached, the treatment of the material G is terminated. The material G is dried by the treatment during a treatment time t.sub.V1 of 42 minutes to a residual moisture content f.sub.G,V1,R of 2.75%.

[0083] In Test 2 (V.sub.2), the material temperature T.sub.G,V2 falls during the treatment of the material G in the first treatment period I, lasting 15 minutes, from an initial material temperature T.sub.G,V2,A of 32.3° C. to a material temperature T.sub.G,V2 of 29.4° C. After 5 minutes, in the first treatment period I, the material minimum temperature T.sub.G,V2,min of 27.9° C. is reached. In the second treatment period II, which lasts 27 minutes, the material G is then heated to the material end temperature T.sub.G,V2,E of 42.1° C.; when this temperature is reached, the treatment of the material G is terminated. The material G is dried by the treatment to a residual moisture content f.sub.G,V2,R of 4.75% for a treatment time t.sub.V2 of 44 minutes.

[0084] In summary, with the same material G to be treated of a batch during drying to a prespecified material end temperature T.sub.G, . . . , E of 42.1° C. in Tests 1 (V.sub.1) and 2 (V.sub.2), due to the different drying gas moisture contents f.sub.TG, . . . , FE at the fluid inlet 11, different residual moisture contents f.sub.G, . . . , R are reached. The residual moisture content f.sub.G,V1,R in the material G after the treatment according to Test 1 is lower than the residual moisture content f.sub.G,V2,R in the material G after the treatment according to Test 2, despite the shorter treatment time t. With respect to the higher residual moisture content f.sub.G,V2,R of Test 2 (V.sub.2), the difference between the residual moisture content f.sub.G,V1,R for Test 1 (V.sub.1) and the residual moisture content f.sub.G,V2,R for Test 2 (V.sub.2) after the treatment time t of the corresponding test is 42.1%.

[0085] The table in FIG. 6 shows measurement data from Test 3 (V.sub.3), in which the fluidization chamber 6 of the fluidization apparatus 1 was already preconditioned at the fluid inlet 11 with a drying gas TG that has a drying gas temperature T.sub.TG,V3,FE of 65° C., a drying gas moisture content f.sub.TG,V3,FE of 7 g/kg and a drying gas volume flow V.sub.TG,V3,FE of 70 m.sup.3/h.

[0086] FIG. 7 shows a table with measurement data for Test 4 (V.sub.4), in which the fluidization chamber 6 of the fluidization apparatus 1 was preconditioned at the fluid inlet 11 with a drying gas TG that has a drying gas temperature T.sub.TG,V4,FE of 65° C., a drying gas moisture content f.sub.TG,V4,FE of 19.5 g/kg, and a drying gas volume flow V.sub.TG,V4,FE of 70 m.sup.3/h.

[0087] As such, Tests 3 (V.sub.3) and 4 (V.sub.4) differed only in the drying gas moisture content f.sub.TG, . . . , FE of the drying gas TG.

[0088] The diagram in FIG. 8 shows the material temperature T.sub.G, . . . during the treatment of the material G of a batch in the fluidization apparatus 1 of the fluidization apparatus unit 2 for Tests 3 (V.sub.3) and 4 (V.sub.4).

[0089] As already explained in FIG. 2, during the treatment of the material G of a batch in the fluidization apparatus 1 in a first treatment period I, at least part of a liquid F.sub.G which constitutes the moisture content f.sub.G, . . . in the material G evaporates from the material G of the batch introduced into the fluidization chamber 6 as the result of the supplied heat Q provided by means of the drying gas TG, such that the material G of the batch cools down from an initial material temperature T.sub.G, . . . , A to a material minimum temperature T.sub.G, . . . , min because of an associated removal of evaporation heat ΔQ.sub.V.

[0090] In a second treatment period II, more liquid F evaporates as a result of the supplied heat Q provided by means of the drying gas TG, such that the material G in the batch heats up to a material end temperature T.sub.G, . . . , E and the moisture content f.sub.G, . . . of the material of the batch is reduced to a residual moisture content f.sub.G, . . . , R during the treatment.

[0091] In Test 3 (V.sub.3), the material temperature T.sub.G,V3 falls during the treatment of the material G in the first treatment period I, lasting 25 minutes, from an initial material temperature T.sub.G,V3,A of 33.5° C. to a material temperature T.sub.G,V3 of 28.4° C., with the material minimum temperature T.sub.G,V3,min of 24.3° C. being reached after 5 minutes in the first treatment period I. In the second treatment period II, which lasts 14 minutes, the material G is then heated to the material end temperature T.sub.G,V3,E of 42.1° C.; when this temperature is reached, the treatment of the material G is terminated. The material G is dried by the treatment to a residual moisture content f.sub.G,V3,R of 2.84% during a treatment time t.sub.V3 of 39 minutes.

[0092] In Test 4 (V.sub.4), the material temperature T.sub.G,V4 falls during the treatment of the material G in the first treatment period I, which lasts 30 minutes, from an initial material temperature T.sub.G,V4,A of 33.0° C. to a material temperature T.sub.G,V4 of 29.8° C. After 5 minutes, in the first treatment period I, the material minimum temperature T.sub.G,V4,min of 28.3° C. is reached. In the second treatment period II, which lasts 17 minutes, the material G is then heated to the material end temperature T.sub.G,V4,E of 42.1° C.; when this temperature is reached, the treatment of the material G is terminated. The material G is dried by the treatment to a residual moisture content f.sub.G,V4,R of 4.95% during a treatment time t.sub.V4 of 47 minutes.

[0093] In summary, with the same material G to be treated of a batch during drying to a prespecified material end temperature T.sub.G, . . . , E of 42.1° C. in Tests 3 (V.sub.3) and 4 (V.sub.4) due to the different drying gas moisture contents f.sub.TG, . . . , FE at the fluid inlet 11, different residual moisture contents f.sub.G, . . . , R are reached. The residual moisture content f.sub.G,V3,R in the material G after the treatment according to Test 3 is lower than the residual moisture content f.sub.G,V4,R in the material G after the treatment according to Test 4, despite the shorter treatment time t. With respect to the higher residual moisture content f.sub.G,V4,R of Test 4 (V.sub.4), the difference between the residual moisture content f.sub.G,V3,R for Test 3 (V.sub.3) and the residual moisture content f.sub.G,V4,R for Test 4 (V.sub.4) after the treatment time t of the corresponding test is 42.6%.

[0094] Such fluctuations in the residual moisture content f.sub.G, . . . , R in the treated material G, as arose in Tests 1 (V.sub.1) to 4 (V.sub.4), can, as already explained, lead to difficulties in further processing, either due to an excessive residual moisture content f.sub.G, . . . , R—such that there is a risk of microbiological contamination—or due to insufficient residual moisture content f.sub.G, . . . , R—such that problems can arise, for example, when the material G is subsequently compressed into tablets.

[0095] In Tests 5 (V.sub.5) to 8 (V.sub.8), the preferred method for drying the material G in the fluidization apparatus unit 2 was used, wherein the material end temperature T.sub.G, . . . , E is found as the sum of the individual material minimum temperature T.sub.G, . . . , min for the material of a batch and a prespecified increase temperature T.sub.+ that is the same for each batch of the material G.

[0096] Tests 5 (V.sub.5) and 6 (V.sub.6), as well as Tests 7 (V.sub.7) and 8 (V.sub.8) are regarded as respective batches of the same material G.

[0097] The temperature difference between the material minimum temperature T.sub.G,V1,min and the material end temperature T.sub.G,V1,E from Test 1 (V.sub.1) was selected as the increase temperature T.sub.+ for Tests 5 (V.sub.5) to 8 (V.sub.8). The increase temperature T.sub.+ was thus 18.1° C. for all of Tests 5 (V.sub.5) to 8 (V.sub.8), corresponding to Test 1 (V.sub.1).

[0098] In all of Tests 5 (V.sub.5) to 8 (V.sub.8), the drying gas temperature T.sub.TG, . . . , FE which was pre-set for each of Tests 5 (V.sub.5) to 8 (V.sub.8) respectively, the drying gas moisture content f.sub.TG, . . . , FE, and the drying gas volume flow V.sub.TG, . . . , FE at the fluid inlet 11 of the fluidization apparatus 1 were kept constant over the treatment time t.

[0099] The table in FIG. 9 shows measurement data from test 5 (V.sub.5), in which the fluidization chamber 6 of the fluidization apparatus 1 has already been preconditioned at the fluid inlet 11 with a drying gas TG that has a drying gas temperature T.sub.TG,V5,FE of 60° C. a drying gas moisture content f.sub.TG,V5,FE of 8.2 g/kg and a drying gas volume flow V.sub.TG,V5,FE of 70 m.sup.3/h.

[0100] FIG. 10 shows a table of measurement data for Test 6 (E.sub.6), in which the fluidization chamber 6 of the fluidization apparatus 1 was preconditioned at the fluid inlet 11 with a drying gas TG which has a drying gas temperature T.sub.TG,V6,FE of 60° C., a drying gas moisture content f.sub.TG,V6,FE of 20 g/kg, and a drying gas volume flow V.sub.TG,V6,FE of 70 m.sup.3/h.

[0101] As such, Tests 5 (V.sub.5) and 6 (V.sub.6) differed only in the drying gas moisture content f.sub.TG, . . . , FE of the drying gas TG.

[0102] The process end temperature T.sub.V5,E during Test 5 (V.sub.5) was therefore the sum of the material minimum temperature T.sub.G,V5,min and the increase temperature T.sub.+, and was 42.1° C.—i.e., the treatment of the material G in the fluidization chamber 6 of the fluidization apparatus 1 was stopped when the material end temperature T.sub.G,V5,E of 42.1° C. was reached.

[0103] The process end temperature T.sub.V6,E during Test 6 (V.sub.6) was therefore the sum of the material minimum temperature T.sub.G,V6,min and the increase temperature T.sub.+, and was 48.6° C.—i.e., the treatment of the material G in the fluidization chamber 6 of the fluidization apparatus 1 was stopped when the material end temperature T.sub.G,V6,E of 48.6° C. was reached.

[0104] The diagram shown in FIG. 11 depicts the material temperature T.sub.G, . . . during the treatment of the material G of a batch in the fluidization apparatus 1 of the fluidization apparatus unit 2 for the Tests 5 (V.sub.5) and 6 (V.sub.6).

[0105] As already explained in FIG. 2, during the treatment of the material G of a batch in the fluidization apparatus 1 in a first treatment period I, at least part of a liquid F.sub.G which constitutes the moisture content f.sub.G, . . . in the material G evaporates from the material G of the batch introduced into the fluidization chamber 6 as a result of a supplied heat Q provided by means of the drying gas TG, such that the material G of the batch cools down from an initial material temperature T.sub.G, . . . , A to a material minimum temperature T.sub.G, . . . , min because of an associated removal of evapora-tion heat ΔQ.sub.V.

[0106] In a second treatment period II, more liquid F evaporates as a result of the supplied heat Q provided by means of the drying gas TG, such that the material G in the batch heats up to a material end temperature T.sub.G, . . . , E and the moisture content f.sub.G, . . . of the material G of the batch is reduced to a residual moisture content f.sub.G, . . . , R during the treatment.

[0107] In Test 5 (V.sub.5), the material temperature T.sub.G,V5 falls during the treatment of the material G in the first treatment period I, which lasts 30 minutes, from an initial material temperature T.sub.G,V5,A of 48.1° C. to a material temperature T.sub.G,V5 of 30° C. After 5 minutes, in the first treatment period I, the material minimum temperature T.sub.G,V5,min of 24.0° C. is reached. In the second treatment period II, which lasts 17 minutes, the material G is then heated to the material end temperature T.sub.G,V5,E of 42.1° C.; when this temperature is reached, the treatment of the material G is terminated. The material G is dried by the treatment to a residual moisture content f.sub.G,V5,R of 2.91% during a treatment time t.sub.V5 of 47 minutes.

[0108] In Test 6 (V.sub.6), the material temperature T.sub.G,V6 falls during the treatment of the material G in the first treatment period I, which lasts 35 minutes, from an initial material temperature T.sub.G,V6,A of 46.2° C. to a material temperature T.sub.G,V6 of 35.6° C. After 10 minutes, in the first treatment period I, the material minimum temperature T.sub.G,V6,min of 30.5° C. is reached. In the second treatment period II, which lasts 45 minutes, the material G is then heated to the material end temperature T.sub.G,V6,E of 48.6° C.; when this temperature is reached, the treatment of the material G is terminated. The material G is dried by the treatment to a residual moisture content f.sub.G,V6,R of 2.84% during a treatment time t.sub.V6 of 80 minutes.

[0109] Overall, using the preferred method in the treatment, in particular drying, of the material G in a so fluidization apparatus 1 of the fluidization apparatus unit 2 substantially achieves the same residual moisture content f.sub.G, . . . , R. With respect to the higher residual moisture content f.sub.G,V5,R of Test 5 (V.sub.5), the difference between the residual moisture content f.sub.G,V5, R for Test 5 (V.sub.5) and the residual moisture content f.sub.G,V6,R and Test 6 (V.sub.6) after the treatment time t of the corresponding test is only 1.7%.

[0110] The table in FIG. 12 shows measurement data from Test 7 (V.sub.7), in which the fluidization chamber 6 of the fluidization apparatus 1 was already preconditioned at the fluid inlet 11 with a drying gas TG that has a drying gas temperature T.sub.TG,V7,FE of 65° C., a drying gas moisture content f.sub.TG,V7,FE of 8 g/kg and a drying gas volume flow V.sub.TG,V7,FE of 70 m.sup.3/h.

[0111] FIG. 13 shows a table of measurement data for experiment 8 (V.sub.8), in which the fluidization chamber 6 of the fluidization apparatus 1 was preconditioned at the fluid inlet 11 with a drying gas TG which has a drying gas temperature T.sub.TG,V8,FE of 65° C., a drying gas moisture content f.sub.TG,V8,FE of 20 g/kg and a drying gas volume flow V.sub.TG,V8,FE of 70 m.sup.3/h.

[0112] As such, Tests 7 (V.sub.7) and 8 (V.sub.8) differed only in the drying gas moisture content f.sub.TG, . . . , FE of the drying gas TG.

[0113] The process end temperature T.sub.V7,E during Test 7 (V.sub.7) was therefore the sum of the material minimum temperature T.sub.G,V7,min and the increase temperature T.sub.+, and was 41.8° C.—i.e., the treatment of the material G in the fluidization chamber 6 of the fluidization apparatus 1 was stopped when the material end temperature T.sub.G,V5,E of 41.8° C. was reached.

[0114] The process end temperature T.sub.V8,E during Test 8 (V.sub.8) was therefore the sum of the material minimum temperature T.sub.G,V8,min and the increase temperature T.sub.+, and was 49.3° C.—i.e., the treatment of the material G in the fluidization chamber 6 of the fluidization apparatus 1 was stopped when the material end temperature T.sub.G,V6,E of 49.3° C. was reached.

[0115] The diagram in FIG. 14 shows the material temperature T.sub.G, . . . during the treatment of the material G of a batch in the fluidization apparatus 1 of the fluidization apparatus unit 2 for Tests 7 (V.sub.7) and 8 (V.sub.8).

[0116] As already explained in FIG. 2, during the treatment of the material G of a batch in the fluidization apparatus 1 in a first treatment period I, at least part of a liquid F.sub.G which constitutes the moisture content f.sub.G, . . . in the material G evaporates from the material G of the batch introduced into the fluidization chamber 6 as a result of a supplied heat Q provided by means of the drying gas TG, such that the material G of the batch cools down from an initial material temperature T.sub.G, . . . , A to a material minimum temperature T.sub.G, . . . , min because of an associated removal of evapora-tion heat ΔQ.sub.V.

[0117] In a second treatment period II, liquid F.sub.G continues to evaporate due to the supplied heat Q provided by the drying gas TG, such that the material G of the batch heats up to a material end temperature T.sub.G, . . . , E, and the moisture content f.sub.G, . . . of the material G of the batch is reduced to a residual moisture content f.sub.G, . . . , R during the treatment.

[0118] In Test 7 (V.sub.7), the material temperature T.sub.G,V7 falls during the treatment of the material G in the first treatment period I, which lasts 25 minutes, from an initial material temperature T.sub.G,V7,A of 48.2° C. to a material temperature T.sub.G,V7 of 27.5° C. After 5 minutes, in the first treatment period I, the material minimum temperature T.sub.G,V7,min of 23.7° C. is reached. In the second treatment period II, which lasts 15 minutes, the material G is then heated to the material end temperature T.sub.G,V7,E of 42.1° C.; when this temperature is reached, the treatment of the material G is terminated. The material G is dried by the treatment to a residual moisture content f.sub.G,V7,R of 2.40% during a treatment time t.sub.V7 of 40 minutes.

[0119] In Test 8 (V.sub.8), the material temperature T.sub.G,V8 falls during the treatment of the material G in the first treatment period I, which lasts 30 minutes, from an initial material temperature T.sub.G,V8,A of 52.4° C. to a material temperature T.sub.G,V8 of 36.2° C. After 5 minutes, the material minimum temperature T.sub.G,V8,min of 31.2° C. is reached in the first treatment period I. In the second treatment period II, which lasts 20 minutes, the material G is then heated to the material end temperature T.sub.G,V8,E of 49.3° C.; when this temperature is reached, the treatment of the material G is terminated. The material G is dried by the treatment to a residual moisture content f.sub.G,V8,R of 2.67% during a treatment t.sub.V8 time Lis of 50 minutes.

[0120] Overall, using the preferred method in the treatment, in particular drying, of the material G in a fluidization apparatus 1 of the fluidization apparatus unit 2 substantially achieves the same residual moisture content f.sub.G, . . . , R. With respect to the higher residual moisture content f.sub.G,V8,R of Test 8 (V.sub.8), the difference between the residual moisture content f.sub.G,V7,R for Test 7 (V.sub.7) and the residual moisture content f.sub.G,V8,R for Test 8 (V.sub.8) after the treatment time t of the corresponding test is only 10.1%.

[0121] With the preferred method, a material G from a first batch (V.sub.5, V.sub.7) after treatment in the fluidization apparatus unit 2 has essentially the same residual moisture content f.sub.G, . . . , R as an identical material G from a second batch (V.sub.6, V.sub.8).

[0122] As such, the fluctuations in the residual moisture content f.sub.G, . . . , R in the treated material G of the different batches are negligible according to the preferred method compared to the known methods, and the treated material G can be readily sent for further processing—for example, tablet compression.