EP1933104A1 - Method and device for conditioning free-flowing fluidisable bulk solids - Google Patents

Abstract

The device (10) has a processing container, which has an inlet (11) for supply of the bulk material and an outlet arranged below for discharging the bulk material. The process container has a processing space arranged below the inlet with a heat transferring element. A lower limit (50) of the processing space has openings. The lower limit has a lower plane and an upper plane, which are moving partially relative to each other and form free cross section surfaces of changing sizes. An independent claim is also included for a method for conditioning free flowing bulk materials.

Description

The invention relates to an apparatus and a method for conditioning free-flowing, fluidizable solids according to the preambles of claims 1 and 15.

In the production and processing of free-flowing, fluidisable bulk materials, these are subjected to a large number of process engineering operations. For storage, packaging or to initiate subsequent process steps, it is often necessary to condition these bulk materials, for example, to cool, dehumidify or the like. In particular, for storing bulk materials, it is necessary that both their temperature and their moisture content is adjusted correctly, for example, to prevent spoilage of the products or agglomeration of the bulk materials. It may also be necessary that the respective bulk materials must be heated.

For the conditioning of granular bulk materials, it is known that the bulk materials are brought into contact with a gaseous medium, whereby the Heat transfer occurs. The resulting temperature difference of the gaseous medium and the amount of the medium determine the amount of heat transferred. Since the heat capacity of gases is low and the available temperature difference is limited in particular for cooling, this method often requires significant amounts of gas. The heat transfer is often used in combination with a mass transfer, so that the bulk material is dried. In addition, there is a discharge of dust and small particles, so that dedusting plants are mandatory to install. Drum coolers or fluidized bed apparatus without internals are examples of such conditioning equipment.

Another way to condition granular bulk materials is to bring them in direct contact with heat transfer surfaces. These heat transfer surfaces are flowed through by a heat transfer medium, so that the bulk material remains spatially separated from the heat transfer medium. The heat transfer coefficients are low in comparison to a flowing contact with the heat transfer medium, since the contact surface is smaller and limited only to the contact surfaces. In addition, the permitted temperature difference between the bulk material and the heat transfer surfaces is limited by the product properties of the bulk material.

Due to an existing relative movement between the heat transfer surfaces and the bulk material, it can also lead to abrasion of the bulk material. The EP 444 338 A1 describes a shaft cooler of the type mentioned. A variant of a shaft cooler is from the WO 98/25091 known, in which gravitational bulk material slides along cooling surfaces. The bulk material is pressed downwards by gravity and the overpressure present in the upper part of the cooler, inclined baffles cause the bulk material to be in contact with an inner cooling body, so that cooled bulk material can be removed at atmospheric pressure at the lower outlet.

An additional option for conditioning granular bulk materials is a combination of direct and indirect heat transfer. The GB 1,299,246 A1 describes a fluidized bed apparatus with juxtaposed, vertically extending chambers in which heat transfer surfaces are arranged. From below, a fluidizing gas is flowed in, so that the bulk material is kept in a fluidized state. By a flow guide, a horizontal transport is ensured by the introduction chamber to the discharge, wherein the discharge is arranged above the inflow floor; without a flow from below no bulk material transport will take place and the apparatus will run full if the supply is not interrupted. The heat transfer in such a fluidized bed apparatus with built-in heat transfer surfaces takes place partly via the gas and partly directly on the heat transfer surfaces. The heat transfer rates are high, since the fluidized bed intensifies the heat transfer from the heat transfer surfaces to the gas and the gas in turn reaches the entire surface of the bulk material.

In order to provide the required heat transfer surfaces available, several sections must be arranged horizontally next to each other, since the maximum height of the fluidized bed is limited because of the necessary, uniform residence time distribution of the solid particles as they pass through the apparatus. In order for the product transport to work, a considerable pressure loss must be applied through the gas distributor or distributor plate. The gas velocity in the fluidized bed must be set to be approximately 6-7 times the gas velocity at which the bed begins to whirl. The Gasverteil- or distributor bottom consists of perforated plates. The holes must be chosen so small that no product falls through. As a result, they become susceptible to contamination by contamination, whereby the fluidization deteriorates and the transport of solids is hindered. If too large a number of free cross-sectional areas are clogged, the gas distribution trays must be thoroughly cleaned. To avoid the clogging of the free cross-sectional areas as far as possible, the process gas must be dedusted consuming. Due to the high amount of gas required to achieve a fluidization and a Mass transport is necessary, the treatment of the process gas is extremely expensive.

The US 3,721,107 describes a cooling tower with a fixed distributor bottom and vibrating conveyors for discharging a cooled product. Fluidization of the bulk material does not take place. A similar device is in the US 2,656,007 described.

The object of the present invention is to provide a device and a method with which, when using a minimum amount of gas for fluidizing the bulk material, a high efficiency of the heat and optionally mass transfer can be achieved and reliable process control can be ensured.

According to the invention this object is achieved by a device having the features of claim 1 and a method according to the features of claim 15. Advantageous embodiments and further developments of the invention are specified in the respective subclaims.

The apparatus for conditioning flowable, fluidizable bulk materials having a process container having an inlet for supplying the bulk material and an outlet arranged below the inlet for discharging the solids, the process container having a process space arranged below the inlet with at least one heat transfer element arranged therein can be traversed by a gaseous or liquid medium and in which below the heat exchanger or a lower boundary is arranged with openings through which a process gas from below into the process chamber can be introduced, provides a lower boundary, which is an upper level and a lower level which are at least partially displaceable relative to each other and form the free cross-sectional areas of variable size. Due to the movable design of the two levels in total or parts of the planes to each other, which together form the lower boundary or part of the lower boundary of the process space, it is possible to adapt the Device on the one hand to the required conditioning tasks and on the other hand to the given properties of the bulk material such as particle size, particle size distribution, stickiness etc. make. Depending on the type and amount of the existing process gas, it is possible to make an adjustment of the size of the free cross-sectional areas. It is also possible that in the case of added free cross-sectional areas they are increased so that flowing bulk material eliminates the deposits. The transport of the bulk material takes place differently than in the conventional fluidized bed dryers or fluidized bed coolers in the direction of gravity from top to bottom with an outlet below the lower boundary of the process chamber. Here, the countercurrent process gas quantity is much smaller compared to conventional fluidized bed plants. The bulk material thus passes down through the lower boundary and exits the device through an outlet which is below the actual process space in which the conditioning takes place. The free cross-sectional areas thus serve simultaneously for the process gas passage as well as for the solids passage. The terms "top" and "bottom" are to be understood in the usual meaning with respect to the direction of gravity.

A development of the invention provides that the lower level of the lower boundary of the process space is completely or partially lowered, so that the lower level or parts or elements thereof seen from the upper level is beyond the bulk material or lie. By lowering the lower level, the free cross-sectional areas, through which both the process gas and the bulk material pass through, can be changed in size. When lowering the free cross-sectional areas are increased. Of course, it is provided that, conversely, to reduce the size of the free cross-sectional areas or of the flow or passage cross-section, the plane is raised. In addition to a displaceability of the first plane in or against the gas flow direction, it is possible to make these displaceable, thereby increasing or decreasing the flow and passage cross-sections. The upper level is preferably arranged rigidly at the lower boundary of the process space in order to ensure the easiest possible assignment of the levels to one another. in principle it is possible that both levels are movably displaced in the region of the lower boundary of the process space and can be changed by a corresponding actuation in position. For example, the planes may be tiltable or rotatable relative to each other. A displacement of the planes to each other can be done manually or by motor, in particular pneumatically. If one of the levels consists of several components or elements, these can be designed to be movable individually or in groups so as to provide different cross sections of the free cross-sectional areas distributed over the area of the lower boundary of the process space.

In an advantageous embodiment of the invention it is provided that the upper level of roof-shaped elements, in particular elongated profiles are formed, which are arranged spaced from each other. The roof-shaped configuration of the profiles prevents an accumulation of bulk particles on the surface of the upper level, since the particles or solid particles slide down along the inclined surfaces. Furthermore, the roof-shaped profile arrangement increases the stability of the elements in the upper level.

The lower level may also be formed of roof-shaped elements, preferably with a flat roof angle. Here, the arranged below the upper level roof-shaped elements are dimensioned so that they cover the spaces between the elements of the upper level seen in the flow direction, that are offset from the profiles or elements of the upper level. As a result, an overall closed lower boundary of the process space is formed in the projection, the free cross-sectional areas for flowing through or passing through process gas and bulk material are formed by a distance of the elements from one another, so that the process gas flow and the bulk material flow undergo a directional deflection. As a result of the overlapping, it is possible for the lower boundary of the process space to be completely closed or for the planes to be arranged relative to one another in such a way that there is a minimal gap or a minimum free cross-sectional area through which the process gas can flow, but the bulk material can not pass due to the particle size or the angle of repose. The roof-shaped or otherwise formed lower-level elements may be individually, in groups or jointly displaced relative to the upper level, in particular lowered or raised in order to achieve the desired effects within the process space. For this purpose, the individual elements or profiles can each be coupled to an actuator by which a single control is possible.

In order to ensure that a minimum gas flow can always pass through the free cross-sectional areas and openings in the planes, it is provided in a development that spacers are arranged between the lower and the upper level or between the elements of the levels, which in one method of the planes or elements towards each other form a mechanical stop. If the free cross-sectional areas are increased, ie beyond that level in which the angle of repose of the bulk material prevents leakage through the free cross-sectional areas, the result is that the openings themselves are cleaned by the passing bulk material, so that it is also possible to supply dusty gas to the bulk material layer without the free cross-sectional areas becoming clogged and closing the lower boundary. A self-cleaning effect occurs as soon as the bulk material passes gravitationally against the gas flow through the free cross-sectional areas. The adjustability of the free cross-sectional areas also allows the processing of bulk materials of different grain sizes.

A further embodiment provides that a plurality of heat exchanger elements are arranged one above the other, which are flowed through separately by a heat transfer medium. As a result, different heat transfer grades or temperature gradients can be set. The heat transfer elements, which may also be arranged in packages of heat transfer elements, are arranged in particular perpendicular to the gas flow direction, ie predominantly horizontally, and consist of a plurality of juxtaposed and superimposed, fluid-flowed tubular body or tube body sections of a heat transfer element. The heat transfer elements are formed as a plurality of individual tubular body or as a meander-like bent tube, or the one of a Heat transfer medium, such as gas or liquid, is flowed through. The individual heat exchanger elements are formed horizontally spaced from each other to allow bulk material and process gas to pass from top to bottom and vice versa through the process space. If a plurality of layers of heat transfer elements are arranged one above the other, then they are preferably offset relative to one another so that the heat transfer elements of the lower level are below the interstices of the heat transfer elements of the next higher level. Individual heat exchanger elements can be combined to form packages of heat exchanger elements.

The arrangement of the heat transfer elements or tubular body within the process chamber, the gas flow and the flow behavior of the fluidized bulk material is made uniform, so that especially in fine-grained bulk solids blistering and eruptive passage of the process gas through the packed layer is avoided. The vertical arrangement of the heat exchanger elements or packages allows a space-saving design, which has a small footprint and is limited only by the height.

A development of the invention provides that at the upper end of the process chamber, a return line for the process gas is arranged, which returns the process gas to a fan or compressor. To accelerate the process gas different devices can be used, in particular rotary blower or centrifugal fans are provided. Due to the self-cleaning capability of the device, it is also possible to use a non-dedusted process gas. It is also possible that a conditioning unit for the process gas is connected upstream of the fan or compressor, so that the process gas is cleaned, dehumidified or optionally dedusted. The conditioning unit can adapt the process gas to the desired conditioning properties of the bulk material.

Below the process space, a discharge lock is arranged, through which the bulk material passed through the process space is removed. The Discharge lock ensures a pressure seal, so that within the process chamber a controllable process pressure prevails.

The lower boundary of the process chamber is designed so that the angle of repose of the solids is prevented from exiting at closed levels or even at minimally spaced levels. If the distance is increased or the free cross-sectional areas are increased, it is possible to ensure a bulk material transport even without process gas or recycle gas, since the particles of the bulk material pass through the process space gravitationally driven. Thus, a discharge of the bulk material in case of failure of the fan is possible, so that the conditioning process does not have to be interrupted even with a defect or at least can be stopped controlled.

The inventive method for conditioning, in particular cooling free-flowing, fluidizable bulk materials in a process space in which introduced from above the bulk material and discharged below a lower boundary of the process chamber via an outlet, provides that the lower boundary of the process chamber has free cross-sectional areas, the used simultaneously for the discharge of the bulk material down and the supply of process gas in countercurrent upward into the process space, wherein the free cross-sectional areas within the lower limit depending on a process variable, in particular a measured pressure or a level within the process space increased or be downsized. The flow rate of the bulk material is controlled by preferably periodically opening or closing or increasing or decreasing the free cross-sectional areas within the lower boundary, with the aim of keeping the pressure within the packed bed or fluidized bed or level constant and a smooth process with uniform results to obtain.

In a pressure-based control, the pressure within the fluidized bed is proportional to the amount of bulk material in the fluidized bed. By eg periodic opening and closing or increasing or decreasing the openings within the lower boundary of the process space is a uniform distribution of Dwell time of the bulk material in the device achieved, so that a uniform Konditionierergebnis while ensuring a secure process is possible. The pressure loss of the lower boundary, which may consist of a fixed plane with roof-shaped profiles, between which there is a distance, is very low because of the relatively low gas velocities. The gas distribution takes place primarily via the bulk material movement, through which the gas flow is deflected uniformly and distributed over the entire cross-sectional area of the process space.

The process gas is preferably injected into the bulk material at a relatively low velocity, which is between the vortex point velocity of the bulk material and half the Einzelkornsinkgeschwindigkeit the mean particle diameter of the bulk material, so that there is a whirling movement within the process space. In the area of the passage openings, fluidized bulk particles deflected downward by impulse exchange are moved in the direction of the outlet.

The process gas can be conducted as cycle gas, whereby an environmental impact is avoided or reduced, wherein the process gas can be conditioned before blowing into the packed bed. By conditioning is meant in particular the cleaning, cooling or heating or dehumidifying.

To compensate for process gas losses or to prevent the loading of the process gas with dust or moisture does not rise above a critical value, conditioned fresh gas can be supplied to the cycle gas.

The control of the enlargement or reduction of the free cross-sectional areas via a parameter measurement, in particular level or pressure measurement within the process space. If a predetermined pressure or a certain level is reached or exceeded, the openings are enlarged. The duration and the interval times of the opening depend on the desired throughput.

A certain pressure value is measured, for example, when the bulk material has reached the upper end of the heat transfer element or the packages of heat transfer elements. If this is the case, the free cross-sectional areas are increased, for example by lowering the lower element level or parts thereof. If the predetermined pressure or level falls below, the cross sections are reduced again until the predetermined pressure value or level value is reached again.

The conditioning process can be carried out both continuously and batchwise, with an internal dedusting is possible because only small amounts of air for conditioning the bulk material are needed.

Figur 1 -

eine schematische Darstellung der Vorrichtung;

Figur 2 -

eine Explosionsdarstellung der Vorrichtung;

Figur 3 -

eine Längsschnittdarstellung der Vorrichtung;

Figur 4 -

eine Längsschnittdarstellung in einem anderen Winkel;

Figur 5 -

eine Detaildarstellung einer unteren Begrenzung; sowie

Figur 6 -

eine Detaildarstellung der Figur 3.

Hereinafter, an embodiment of the invention will be explained in more detail with reference to the accompanying figures. Show it:

FIG. 1 -

a schematic representation of the device;

FIG. 2 -

an exploded view of the device;

FIG. 3 -

a longitudinal sectional view of the device;

FIG. 4 -

a longitudinal sectional view at a different angle;

FIG. 5 -

a detailed representation of a lower limit; such as

FIG. 6 -

a detailed view of the FIG. 3 ,

FIG. 1 shows a schematic representation of a fluidized bed system 10 for conditioning fluidizable, free-flowing bulk materials, such as granulated sugar, fertilizer or the like. The device 10 has an inlet 11 for product delivery. The inlet 11 is arranged at the upper end of the system 10. Below the inlet 11, a process space 12 is formed, in which the bulk material is fluidized. Below the process space 12, an outlet 13 for the product outlet in the conditioned state is provided. Above the outlet 13 a discharge lock 14 is provided, which is driven by a motor and ensures a product discharge under pressure. Within the process space 12 are packages 15, 16, 17 of heat exchanger elements 171 are arranged, in which the heat transfer elements 171 are present in the form of tubular bodies, which are flowed through by a heat transfer medium, for example, cooled or heated liquid or cooled or heated gas. Below the packages 15, 16, 17, a lower boundary 50 of the process chamber 12 is provided with free cross-sectional areas 55, is introduced through the process gas into the process chamber 12.

The packages 15, 16, 17 are supplied by the heat transfer medium via a supply line 21 with the heat transfer medium. In the illustrated schematic arrangement, the heat transfer medium passes through all packages 15, 16, 17 of heat transfer elements from bottom to top and is then passed via a return line 22 to a kind of cooling or heating station. Alternatively, all packages 15, 16, 17 of heat exchanger elements 171 can be supplied separately with a heat transfer medium.

If, for example, the bulk material introduced through the inlet 11 is to be cooled, cooled fluid is introduced through the supply line 21 into the packages 15, 16, 17 of heat transfer elements. At the same time, via a fan 20, which is driven by a motor 201, process gas is introduced into the process space through the lower boundary 50 at a recycle gas inlet point 181. By uniformly distributed over the cross section of the process chamber 12 free cross-sectional areas 55 there is a uniform loading of the bulk material with the process gas. The process gas is, like the heat transfer medium, also passed in countercurrent through the process chamber 12 and simultaneously cools or dries the bulk material, such as granulated sugar. Due to the countercurrent operation, a fluidization of the bulk material within the process chamber 12, so that all bulk material particles are flowed through by the process gas on the one hand and on the other hand get into intensive contact with the heat transfer elements 171 within the packages 15, 16, 17 of heat transfer elements. The heat exchanger elements 171 within the packages 15, 16, 17 of heat exchanger elements additionally ensure a homogenization of the air flow within the process chamber 12 as well as an avoidance of blistering, which occurs or can occur especially in fine-grained bulk solids.

At the upper end of the device 10, a return line 18 is arranged at a process gas outlet 182, so that the recycle gas can be returned to the fan 20. If exhaust gases occur, they are discharged through a drain 180 from the process. Within the return line 18, a conditioning or conditioning unit for the process gas can be switched on.

If fresh process gas is needed, fresh gas 19 is introduced into the return line 18. A load cell 40 measures the pressure and other parameters of the fresh gas.

A pressure measuring unit 30 measures the pressure in the region of the lower limit 50 at the lower end of the process space. If a critical value is reached, an actuator 60 is put into operation via an integrated control unit, which increases or reduces the free cross-sectional areas 55 within the lower limit 50, by lowering or raising the levels 51, 52, not shown, of the lower boundary 50. This serves to control the product pass. In this case, the openings within the lower boundary 50 are not completely closed, so that process gas can pass through, but the passage cross-section is chosen so that the bulk material can not fall through. If a certain level within the process chamber 12 is reached, the pressure loss within the process chamber 12 due to the bulk material therein is so great that the pressure measuring unit 30 determines a corresponding value and then increases the free passage cross-sections. As a result, the bulk material moves through the free cross-sectional areas 55 within the lower boundary 50 and is conveyed through the discharge lock 14 to the outlet and transported away therefrom.

A more detailed structure shows the FIG. 2 which is an exploded perspective view. The device 10 is partially shown and shows an upper part 101 and a lower part 102 with an inlet 11 and an outlet 13. The process gas is introduced through the process gas inlet 181, which is arranged on the lower part 102 and discharged through the process gas outlet 182 on the upper part 101 , Between the upper part 101 and the lower part 102, a package 17 of heat exchanger elements with a plurality of tubular, each other vertically and horizontally offset heat transfer elements 171 is arranged. A feed line 21 and a return line 22 provide for the supply and removal of the heat transfer medium, which is passed in countercurrent, ie from bottom to top through the package 17 of heat transfer elements. The process space 12 Shooting sidewalls are not shown for clarity. Below the package 17 of heat exchanger elements, a lower boundary 50 is arranged, which consists of two levels 51, 52. These levels are formed by roof-shaped profiles 1, 2, whose arrangement in FIG. 5 is shown and will be discussed later. The two levels 51, 52 are mutually displaceable, in the present embodiment, the lower level 51 can be lowered down, while the upper level 52 is fixed. The upper level 52 consists of roof-shaped, spaced-apart longitudinal profiles 2. This prevents that the bulk material remains lying on the profiles 1, 2.

In FIGS. 3 and 4, which show a section of various orientations along the vertical axis of the device 10, it can be seen that the packages 15, 16, 17 of heat transfer elements 171 have separate supply ports and discharge ports. Likewise, the plurality of heat exchanger elements 171, which are arranged substantially horizontally and are arranged transversely to the flow direction of the process gas and to the passage direction of the bulk material, can be recognized. By this arrangement, which extends over the entire height and the entire cross section of the process chamber 12, the bulk material comes into intensive contact with both the heat transfer elements 171 and with the process gas. By the process gas, the bulk material is swirled in countercurrent; Furthermore, a heat transfer and optionally a mass transfer is carried out so that the bulk material is dehumidified or moistened.

Also in the FIGS. 3 and 4 to recognize the roof-shaped embodiments of the lower level 51 and the upper level 52 with a steeper roof-shaped structure. Below the lower limit 50 pneumatic actuators 60 are arranged, which can be lowered to increase the flow cross-section or the free cross-sectional areas 55 within the lower boundary 50. As a result, the lower level 51 of the profiles is lowered, the gap between the profiles of the lower level 51 and the upper level 52 is increased and a larger flow of bulk material is passed through.

The structure of the levels 51, 52 and the lower limit 50 is in the FIG. 5 in which a detail of the lower limit 50 is shown. The upper level 52 is formed by a plurality of parallel, roof-shaped profiles 2, which are arranged spaced from each other. These profiles 2 are preferably fixedly arranged on the lower boundary of the process space 12. Alternatively, these profiles 2 can be designed to be movable. Below the upper level 52, the lower level 51 is arranged with a plurality of slightly roof-shaped profiles 1, which are held by a rail 3 at a fixed distance from each other. The distances can be adjustable. Below this rail 3, the actuators 60 are arranged in the FIG. 5 are not shown. The respective profiles 1, 2 are offset from each other and spaced apart within the plane 51, 52, so that the free spaces formed between the respective profiles 1, 2 in the respective plane 51, 52 are covered by the underlying or overlying plane. The angle of the roof-shaped profiles 1 is chosen so that no bulk material remains on the surface. Between the planes 51, 52 may be provided a permanent distance a, for example, ensured by spacer elements, so that always a minimum amount of process gas can flow through the lower boundary 50 therethrough. The distance a is chosen so that the bulk material can not pass through the flow opening, which is formed by the spacing of the two planes 51, 52 to each other. As a result, it is possible to form a multiplicity of longitudinally extending, free cross-sectional areas 55 between the planes 51, 52, the size of which can be changed by a variation of the distance a.

If a specific pressure level or a certain layer height is reached within the process space 12 or if other product or process parameters are reached, for example the desired temperature or the desired drying, the lower level 51 is lowered via a control device 30 and the flow cross section and the passage cross section between the levels 51, 52 enlarged. As a result, the passage rate is increased if a continuous process takes place, or allows the bulk material to escape during batchwise process control. The entire product, including any resulting dusts, is passed through the free cross-sectional areas 55 transported and falls down into the funnel-shaped lower part 102. The product passing through eliminates any existing contamination in the free cross-sectional areas 55 due to the abrasive effects of the bulk material. The inflow velocity of the process gas in the process chamber 12 is below the speed at which the bulk material would be discharged upward, preferably at a value between the vortex point speed and the half of Einzelkornsinkgeschwindigkeit a bulk material grain with average particle diameter.

As an alternative to a purely linear displacement of the lower level 51, tilting of the levels 51, 52 relative to each other can take place in order to change the size of the free cross-sectional areas 55. It is also possible, in an alternative embodiment, to change the free cross-sectional areas 55 by a displacement in the horizontal plane in order to discharge the bulk material through the lower boundary 50 from the process space 12. In addition to an elongate configuration and pyramidal elements may be provided as upper or lower level.

If fresh gas is introduced into the process, the amount of fresh gas is such that the optionally desired mass transfer, z. B. drying, is possible. The feeding of the bulk material takes place in the upper part 101 of the device 10, which is preferably under a slight negative pressure. If an internal dedusting be provided, a dedusting device, such as a cyclone, also within the upper part 101, which is designed as a hood arranged.

As a result of the passage of the bulk material through the free cross-sectional surfaces 55 within the lower boundary 50, the free cross-sectional areas 55 clean themselves so that dust-containing gas can be supplied to the fluidized bed without the free cross-sectional areas 55 becoming clogged. In the closed state of the lower boundary 50, ie at a minimum spacing of the planes 51, 52 to each other, the cross section is chosen so that the angle of repose of the bulk material prevents leakage of the bulk material. The size of the free cross-sectional areas 55 can be adapted to the grain size of the respective product.

In the FIG. 6 which has an enlarged section of the FIG. 3 represents, the arrangement of the individual profiles 1, 2 can be seen in the respective planes 51, 52. The lower level 51 of the profiles 1 is mounted on a common rail 3 and can be changed via the actuator 60, in this case a pneumatic cylinder, in the vertical position. This is indicated by the double arrow. Between the elongated profiles 1, 2, the likewise elongated free cross-sectional areas 55 are formed through which both the process gas flow from bottom to top and the bulk material can pass from top to bottom. Above the lower boundary 50, a package 17 of heat exchanger elements 171 with a plurality of heat exchanger elements 171 is shown. The individual heat exchanger elements 171 are arranged substantially horizontally and can extend parallel to one another and offset relative to one another, alternatively or additionally, the heat exchanger elements 171 can also be arranged so as to be oriented horizontally in a horizontal orientation.

Instead of a common lowering of the lower level 51 and the elements 1 of the lower level 51, it is possible to individually couple each element 1 or profile 1 with an actuator 60 to lower or raise these individually or in groups. Likewise, the planes 51, 52 can be rotated, shifted or tilted relative to each other. It is also possible to move the individual elements or profiles 1, 2 to each other, to twist or tilt, to cause changes in the free cross-sectional areas 55 to the desired extent.

Claims (20)

Apparatus for conditioning free-flowing, fluidisable bulk materials having a process container having an inlet for supplying the bulk material and an outlet arranged below the inlet for discharging the bulk material, the process container has a process space arranged below the inlet with at least one heat transfer element arranged therein a lower boundary of the process space has openings, characterized in that the lower boundary (50) at least a lower level (51) and an upper level (52), which are at least partially displaced relative to each other and free cross-sectional areas (55) of variable size. Apparatus according to claim 1, characterized in that the lower plane (51) of the boundary (50) or parts thereof against the gas flow direction is lowered. Apparatus according to claim 1 or 2, characterized in that the upper level (52) is rigidly arranged on the lower boundary of the process space (12). Apparatus according to claim 1 or 2, characterized in that the two planes (51, 52) are mutually tiltable, rotatable or slidably mounted. Device according to one of the preceding claims, characterized in that the upper level (52) of roof-shaped elements (2) is formed, which are arranged spaced from each other. Apparatus according to claim 5, characterized in that the roof-shaped elements (2) are formed as elongated profiles. Device according to one of the preceding claims, characterized in that the lower plane (51) is formed of flat or roof-shaped profile elements (1) arranged and dimensioned such that spacings between the roof-shaped elements (2) of the upper plane (52) are covered in the gas flow direction, Device according to one of the preceding claims, characterized in that between the planes (51, 52) spacers are arranged, which ensure a minimum distance (a) between the planes (51, 52). Device according to one of the preceding claims, characterized in that a plurality of heat transfer elements (171) or a plurality of packages (15, 16, 17) of heat transfer elements (171) are arranged one above the other, which are flowed through separately by a heat transfer medium. Device according to one of the preceding claims, characterized in that the packages (15, 16, 17) of heat transfer elements (171) are formed from a plurality within the process space (12) arranged tubular body (171), whose longitudinal extent is substantially perpendicular to the gas flow direction. Device according to one of the preceding claims, characterized in that at the upper end of the process chamber (12) a return line (18) for the process gas to a fan (20) or compressor is arranged. Device according to one of the preceding claims, characterized in that a conditioning unit is connected upstream of a fan (20) or compressor, in which the process gas is cleaned, dehumidified and / or dedusted. Device according to one of the preceding claims, characterized in that below the boundary (50) a discharge lock (14) is arranged. Device according to one of the preceding claims, characterized in that the boundary (50) is formed so that the angle of repose of the bulk material prevents leakage at minimally spaced levels (51, 52). A method for conditioning, in particular cooling free-flowing, fluidizable bulk materials with a process space in which the bulk material is filled from above and discharged below the process space, characterized in that the lower boundary of the process chamber has free cross-sectional areas, the same time for the discharge of the bulk material down and the supply of process gas in countercurrent upward into the process space are used, wherein the free cross-sectional areas within the lower limit depending on a process variable, in particular a measured pressure or a level within the process space increased or decreased. A method according to claim 15, characterized in that the free cross-sectional areas are adjusted such that the process gas velocity in the process space for fluidization of the bulk material between the vortex point velocity of the bulk material and 50% of Einzelkornsinkgeschwindigkeit the mean particle diameter. A method according to claim 15 or 16, characterized in that the process gas is guided as circulating gas. Method according to one of claims 15 to 17, characterized in that the process gas is conditioned prior to injection, in particular dedusted, cooled or dehumidified. Method according to one of claims 15 to 18, characterized in that the process gas conditioned fresh gas is supplied. Method according to one of claims 15 to 19, characterized in that the bulk material supply takes place at a negative pressure.

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