This application is a national stage entry of International Patent Application No. PCT/IB2015/051707, filed Mar. 9, 2015, which claims the benefit of German Patent Application No. DE 102014106122.5, filed Apr. 30, 2014, the disclosures of each of which is incorporated herein by reference in their entirety.
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1. Field of the Invention
The invention relates to a device for removing fluids and/or solid substances from a mixture of particle-shaped materials. For example, the device removes fluids and/or solid substances from a mixture of particle-shaped materials with a container which forms a ring-shaped process chamber with a plurality of cells separated from each other by walls, comprising an inlet cell, intermediate cells and an outlet cell, a feeding installation for conveying the mixture to be treated into the inlet cell of the process chamber, a discharge installation for discharging the mixture treated from the outlet cell of the process chamber, a ventilation installation for feeding in a first fluidisation agent, in particular in the form of overheated vapour, from below into the process chamber through an inflow floor for generating a fluidised bed in the process chamber, a heating installation for preparing the first fluidisation agent in the flow direction before the ventilation installation, swirl impellers for conditioning the flow in the container from the process chamber to the heating installation and which in part also leads to a vapour outlet, and a dust removal installation in the flow path between the process chamber and the heating installation, wherein dust can be guided to the outlet cell via the dust removal installation. A device of this type is in particular suitable for drying bulk products and materials from the food and animal feed industry, although other particle-shaped materials or mixtures from them can also be treated with such a device.
2. Description of Related Art
A plurality of devices of the above-named type are known from the prior art, which generally use overheated vapour as a fluidisation agent. These so-called “fluidised bed vaporisation dryers” are used to charge overheated vapour through bulk products or particle-shaped materials from below and to fluidise them, so that a fluidised bed is created. The material to be treated is here transported from an entry cell in which the material to be treated is introduced into the container and the process chamber, via subsequent method cells through to a discharge cell. In the discharge cell, no inflow occurs from below, so that on the lower end of the discharge cell, the material that has been fully treated can be discharged, for example via a discharge screw conveyor. The container is sealed on the discharge end and on the feeding installation by means of a threshold installation in order to be able to allow the processing sequence to run under overpressure. Particles which are carried along by the vapour are separated on the path from the process chamber to a (vapour) outlet using impellers which generate a swirl and a dust removal installation, in order to then guide the vapour which has been freed of dust to the process chamber following renewed heating in a heating installation via an inflow floor. Such installations are known e.g. from EP 1 956 326 B 1, EP 2 146 167 BI, EP 1 070 223 B1, U.S. Pat. No. 5,357,686 and EP 2 457 649 AI.
With the known devices, impermissible material accumulations or lumps may occur in the area of the material charge, which in the worst case can lead to a total failure of the device. In order to remedy a blockage in the process chamber, the device must namely be switched off, rendered pressureless, and cooled down in order to then manually remove the blockage with impellers or similar.
The object of the invention is thus to further develop the generic device in such a manner that it comprises a higher degree of operational reliability. In particular, the creation of lumps of drying products, i.e. the mixture of particle-shaped materials, is to be fundamentally avoided. The through-flow of the device overall is therefore to be improved.
This object is attained according to the invention by means of the fact that in order to support a transportation of the mixture from the inlet cell to the outlet cell and/or a turbulence of the mixture in the process chamber, the inflow floor comprises first unevenness and/or at least at times a second fluidisation agent, in particular in the form of overheated vapour, can be fed at least into the inlet cell essentially parallel to the inflow floor by means of first nozzles, and/or first flow guidance members are provided above the inflow floor and/or second flow guidance members are provided below the inflow floor.
Here it can be provided that in the inlet cell, a mixing of dried and damp parts of the mixture takes place according to a type of stirrer tank, in the intermediate cells a flow guidance according to a type of flow pipe is realised in order to avoid the mixing of damp parts with dried parts of the mixture, and no fluidisation agent penetrates into the outlet cell through the inflow floor.
It is also recommended that the feeding installation for the mixture is connected with the container in the area of the outlet cell, preferably in the centre of the height of the inlet cell and/or at the level of the upper outlets of the fluidised bed.
Here it can be provided that the feeding installation guides the loosened mixture to the inlet cell via a mechanical transport means, preferably by means of mechanically acting paddles, in particular of a screw conveyor, and/or pre-warmed and/or via air transport, preferably by adding a third fluidisation agent, in particular in the form of overheated vapour through vapour injection into the screw conveyor.
It is preferred that the area of the inflow floor is larger in the inlet cell, preferably doubly the size, of the respective area of the inflow floor of the intermediate cells.
It is further preferred that the inflow floor comprises first openings in the inlet cell and in the intermediate cells, the opening relationship of which preferably decreases from the inlet cell in the direction of the outlet cell.
Devices according to the invention can be characterized by the fact that the inflow floor comprises the first unevenness in the form of deeper lying recesses and/or at least over the first quarter of the process chamber.
It is additionally recommended that the inflow floor points upwards on its edge facing towards the container, and otherwise runs essentially horizontally, wherein the edge is preferably equipped with first openings and/or first unevenness at least over the first quarter of the process chamber.
It can also be provided that the second fluidisation agent can be fed in with a pressure of at least 2 bar above the average pressure in the container and/or in the first quarter of the process chamber.
A screen for the heating installation can be provided, wherein preferably, the screen widens conically in the process chamber from top to bottom, the first nozzles extend between the screen and the inflow floor, and/or the screen comprises two openings and/or second unevenness, preferably in the form of deeper lying recesses.
It is also recommended that the wall between the outlet cell and the inlet cell extends up to the height of the inflow floor, and/or the walls between the inlet cell and a first intermediate cell, between the intermediate cells and between the first intermediate cell and the outlet cell, comprise a vertical distance to the inflow floor, in particular to the edge of the inflow floor.
It is preferred that the first flow guidance members are provided and/or adjustable between the first nozzles.
With the invention, it is further recommended that first second flow guidance members are provided in a torospherical head as part of a discharge guide vane of the ventilation installation, wherein preferably, the ventilation installation comprises a bellows within the discharge guide vane.
Preferred devices according to the invention are characterized by the fact that second second flow guidance members are provided in a torospherical head and/or are attached and/or adjustable on the discharge guide vane, preferably in each case pivoted around a pivot axis which is essentially vertical to the inflow floor or which extends vertically.
It is equally preferred that third second flow guidance members are attached and/or adjustable on inflow floor supporting members, preferably in each case pivoted around a pivot axis which is essentially parallel to the inflow floor or which extends horizontally.
According to the invention, it is also recommended that the number, alignment and/or arrangement of the first and/or second openings, the first and/or second unevenness, the first nozzles and/or the first and/or second flow guidance members is or are determined or changeable for the targeted appliance to the mixture with horizontal transport impulses in the direction of the outlet cell and/or turbulence impulses.
Here it can be provided that the alignment, in particular of the second second and/or third second flow guidance members, and/or the infeed from the second fluidisation agent to the first nozzles via an adjustment installation which can be operated from outside of the container, is changeable.
Further features and advantages of the invention arise from the following description, in which exemplary embodiments of the invention are explained in detail with reference to schematic drawings, in which:
Above the inflow floor 24, walls 25 are arranged in a vertical alignment and essentially extend from an outer wall of the heater 6 to a wall of the container 21 in order to form cells between them in the process chamber 23. The walls 25 can reach down to the inflow floor 24, but must then comprise openings or form an empty space between themselves and the inflow floor 24. The cells formed by the walls 25 are open above, so that the vapour which serves as a first or second fluidisation agents 20a, 20b flow from bottom to top through the cells and carry material or particles to be treated, and if necessary transport them to a subordinate cell.
A first swirl is generated between the process chamber 23 and an extension cone 26 using impellers 29 above the walls 25. As a result, the vertical flow of the vapour is deflected in the process chamber 23 in order to lead to a swirl flow in the extension cone 26. Through the application of the swirl, the vapour together with the particles carried along with it is thus directed onto the wall of the container 21, as a result of which the particles are decelerated, namely through wall friction, so that the decelerated particles then fall back along the wall into the process chamber 23.
In the extension cone 26, a reduction of the flow velocity occurs, which leads to an expansion of the vapour flow out of the cells. The extension cone 26 and an upper area 27 which is adjacent to said cone comprise no fixtures, and are thus an empty space in which while separating the particles the flows from the cells split and at least partially mix with each other. In order to transmit kinetic energy for the purpose of improving the mixture of flow layers with different thermal states, overheated vapour is blown into the upper area 27 via nozzles 34 and 35. Separated particles are vertically conducted away along the wall in the extension cone 26 via ribs 36, while the remainder of the particles together with the vapour enters a central separator in the form of a dust collector 4 in the lid 28 of the container. The ribs 36 here ensure a deceleration of the particles, which facilitates separation. The inner contour of the lid 28 is formed to deflect the flow.
Following the preliminary separation of particles in the empty space, smaller particles are separated by the inflow of the particle-vapour mixture into the dust collector 4. The separated dust then enters an outlet cell 202 in the process chamber 23 via a dust cyclone 33.
The feeding installation 1 enters the pulp to be treated into a first cell in the process chamber 23, which is referred to below as the inlet cell 201. The first or second fluidisation agents 20a, 20b do not, or only to a low degree, flow through the last cell equipped with the discharge installation 3 or outlet cell 202, so that material entering into this cell 202 from above or on the inflow floor 24 lands in the floor area and can be removed via the discharge installation 3, in particular such as that described in EP 2 146 167 B1. One or more intermediate cells 203 are positioned between the inlet cell 201 and the outlet cell 202. In order to guarantee an even and constant fluidisation in the fluidised bed 2, a process control can be used in accordance with EP 2 457 649 A1.
The feeding installation 1 is arranged in such a manner that it enters the pulp into the centre of the inlet cell 201, at the level of the upper extensions of the fluidised bed 2, which provides a lower installation site than with known devices. Additionally, it ensures that the pulp reaches the inlet cell 201 in a loosened and pre-heated state. For this purpose, it comprises a screw conveyor 400 with rotatable paddles 401, as is shown in
The screw conveyor 400 is attached to the container 21 via a docking area 406, and ensures that the pulp is introduced into the inlet cell 201 in a pre-heated and loosened state together with an excess quantity of steam, which immediately escapes upwards in the container 21. The inlet cell 201 preferably covers over a larger area of the inflow floor 24 than each of the remaining cells, so that the pulp which has been fed in is brought into contact with an enlarged floor area with an enlarge quantity of steam, which also again counteracts the formation of lumps. In the inlet cell 201, the pulp is namely still in its dampest state. A doubling of the size of the inlet cell 201 as opposed to the remaining cells has been shown to be particularly advantageous.
The flow from the inlet cell 201 to the outlet cell 202 is conditioned via a plurality of flow guidance members in order to further counteract the formation of lumps, as is described below with reference to
A screen 300, also referred to hereinafter as an apron 300, limits the ring-shaped process chamber 23 inwards. Between the apron 300 and the heater 6, a vapour feed pipe 301 opens out above the inflow floor 24, in order to guide vapour in a transverse direction across the inflow floor 24 via first nozzles 302 to at least one first quarter of the cells, as is shown in
The inflow floor 24 and the apron 300 are designed with perforated sheets 304a, 304b and 305, in order to guide the flow in a targeted way. All perforated sheets 304a, 304b and 305 here comprise holes for a penetration of overheated steam, while some of these perforated sheets, namely perforated sheets 304b and 305, also comprise unevenness to guide said steam. As a result, the perforated sheets 305 of the apron 300 support a flow along the apron down to the inflow floor 24, see the flow lines 310, while the perforated sheets 304b support a flow along the flow lines 312 as an extension of the flow line 311, so that a circular flow is enforced in the fluidised bed 2 essentially vertical to the inflow floor 24, namely from the apron 300 via the inflow floor 24 back to the apron 300. A further circular flow of the same rotational direction is enforced by perforated sheets (not shown) with unevenness in a floor extension which inclines upwards in the direction of the open ends of the cells, which represents an edge 307 which is in contact with the wall of the container 21 as shown in
Between the perforated sheet 304b and the edge 307 and thus between the two vertical circular flows in the same direction, a transportation area 306 runs which secures a horizontal circular path from the inlet cell 201 to the outlet cell 202 to convey the pulp in the process chamber 23. According to the invention, therefore, an uninterrupted transportation path of the pulp in the process chamber 23 is provided by applying horizontal transport impulses in the direction of the discharge area, see flow lines 313, while at least via the first quarter of the process chamber 23 a swirl is enforced with 2 swirls per cell circulating in the same direction, which homogenises the material flow in the process chamber 23 and improves the drying.
The nozzles 302, guide plates 303 and perforated sheets 304a, 304b and 305, can differ for each cell in order to take into account the progressive drying of the pulp. Thus the opening relationship of the perforated sheets 304a to 305 decreases in size from the inlet cell 201 to the outlet cell 202.
The ventilator 7, which as shown in
The pulp must not only be dried in the process chamber 21, but for drying purposes, it must at the same time also be transported from the inlet cell 201 to the outlet cell 202. With the exemplary embodiment shown in
It was discovered in a surprising way that the swirl flow enforced by the discharge guide vane 500 below the inflow floor 24′ in the process chamber has a considerable influence on the transportation of solid materials. In order to be able to influence this transportation of solid materials in a targeted manner, it is recommended according to the invention that adjustable guide plates 600 be provided in the area of the floor 22′, in particular through into the torospherical head 22′a, as shown in
As an alternative to the adjustable guide plates 600, or even in addition to these, further adjustable guide plates 700 can be arranged directly below the inflow floor. This is shown in
The method of functioning of the adjustable guide plates 600 and 700 will now be explained with reference to
Naturally, the adjustable guide plates 600 and 700 can be combined with special perforated sheet designs, as well as guide plates above the inflow floor. Such a combination enables a precise adjustment of the flow required for the respective pulp for the purpose of optimising the drying from an inlet cell to an outlet cell.
The features disclosed in the above description, in the drawings and in the claims can be essential both individually and in any combination required for the realisation of the invention in its different embodiments.
Number | Date | Country | Kind |
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10 2014 106 122 | Apr 2014 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/IB2015/051707 | 3/9/2015 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
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WO2015/166358 | 11/5/2015 | WO | A |
Number | Name | Date | Kind |
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4324544 | Blake | Apr 1982 | A |
5357686 | Jensen | Oct 1994 | A |
6096839 | Chinh | Aug 2000 | A |
20030190417 | Takei | Oct 2003 | A1 |
20120258029 | Krutka | Oct 2012 | A1 |
Number | Date | Country |
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1070223 | Feb 2005 | EP |
Entry |
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International Search Report for PCT/IB2015/051707 dated May 20, 2015. |
Written Opinion of the International Searching Authority for PCT/IB2015/051707. |
Number | Date | Country | |
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20170045293 A1 | Feb 2017 | US |