• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The invention relates to a drying apparatus (1) for drying bulk material, which comprises - a conduit (4) for closed circulation, which is adapted to be filled with a drying medium when the drying apparatus is in operation, - a fl genuine (12). connected to the closed circulation line to provide a desolate wiping medium, heating medium (13). connected to the fan (12) to indirectly heat the drying medium. input means (6), connected to the closed circulation line (4) for conducting bulk material in the closed circulation line, - a drying space (7), connected to the inlet medium (6), where the bulk material is dried by transferring heat energy from the drying medium. separating means (8; 8 '), connected to the drying space (7), for separating bulk material from the drying medium, - an outlet (14) for excess steam, connected to the conduit (4) for closed circulation to release excess steam (10), wherein the separating means (8) comprises a plurality of cyclones (Ba to Bd; B'a to 8'd). The present invention also relates to a method for drying bulk material while using this drying apparatus and to using this drying apparatus for drying bulk material based on wood or bulk material based on agricultural products. The present invention also relates to a combined thermal power plant comprising this drying apparatus.
    公开号:SE0950692A1
    申请号:SE0950692
    申请日:2009-09-22
    公开日:2011-03-23
    发明作者:Bengt-Olof Naeslund
    申请人:Skellefteaa Kraftaktiebolag；
    IPC主号:
    专利说明:

    Also a fan, connected to the closed circulation line, to provide a fl of drying medium, and heating means, connected to the fan, to indirectly heat the drying medium. The drying apparatus also comprises feed means, connected to the closed circulation line, for introducing bulk material into the closed circulation line, and a drying space connected to the feed means, where the bulk material is dried by transferring heat energy from the drying medium. The drying apparatus also comprises an outlet for excess steam, connected to the closed circulation line, for releasing excess steam, and separating means, connected to the drying space, for separating bulk material from the drying medium, the separating means comprising a plurality of cyclones.
    Since the drying apparatus comprises a separating agent comprising a number of cyclones, each cyclone receives only a subset of the flow of bulk material and drying medium. The size of the cyclones can therefore be reduced compared to the single cyclone in the prior art, which means that the pressure drop in each cyclone can be smaller and the centrifugal force on the bulk material can be greater than in the single cyclone in the prior art. The result of this is that although the separation can be carried out in a single step, the separation efficiency and the efficiency of the drying apparatus can be significantly improved.
    Another advantage of the present invention is that the use of a separating agent comprising a plurality of cyclones in the drying apparatus leads to less accumulation of particles in the drying medium. This means that fewer particles are returned with the drying medium to the heater, and consequently fewer particles can also be deposited on the heat-conducting surfaces in the heater. A reduction in the deposition of particles and materials derived from the particles in the heating means greatly increases the operating periods and reduces the maintenance costs for cleaning and replacement of parts in the heater. Yet another advantage of the present invention is that the use of a separating agent comprising a plurality of cyclones surprisingly leads to a large reduction of the contaminants in the material discharging to the external wastewater system. Contaminants such as biochemical oxygen demand (BOD) and chemical oxygen demand (COD) originate from suspended particles of bulk material in the wastewater condensate, which make up a large part of the wastewater from the dryer. The sewage condensate is formed in the process of energy recovery, where the latent friend in the excess vapor released from the dryer is recovered. The dryer of the present invention significantly reduces the amount of particles of bulk material in the excess vapor, and consequently also reduces the amount of particles in the effluent condensate.
    According to the present invention, the above-mentioned object and other objects, which appear from the description in the following, are also achieved with a method for drying bulk material in a drying apparatus according to the present invention, this drying apparatus comprising a closed circulation line, filled with a drying medium the near-drying apparatus is in operation, and wherein this method comprises obtaining a flow of the drying medium with a fan inside the closed circulation line and the drying medium being heated indirectly with heating means. The method also comprises that bulk material is introduced through feed means in a flow of the drying medium inside the closed circulation line and that the bulk material is dried in a drying space by transferring heat energy from the turned drying medium to the bulk material. This method also comprises releasing excess steam via an excess steam outlet from the closed circulation line and separating the bulk material from the drying medium with a separating agent comprising a plurality of cyclones.
    Furthermore, a combined thermal power plant is also described which comprises a drying apparatus according to the present invention. In addition, the use of a drying apparatus according to the present invention for drying materials based on wood is described. The use of a drying apparatus according to the present invention for drying materials based on agricultural products is also described.
    The present invention will be better understood with reference to the following detailed description when read in conjunction with the accompanying drawings, in which like reference numerals refer to like parts throughout several views and in which: Figure 1 illustrates a schematic process diagram of a drying apparatus according to the invention; variant of the separating means.
    Figure 2 illustrates a second variant of the separating means of the drying apparatus according to the invention.
    Figure 3 illustrates a sectional view of the length of the first variant of separating means shown in Figure 1.
    Figure 4a illustrates a schematic cross-sectional view of the first variant of three cyclone separating means.
    Figure 4b illustrates a schematic cross-sectional view of the first variant of six cyclone separating means.
    Figure 5 illustrates a schematic process diagram for a combined heat and power plant integrated with a fuel factory with a drying apparatus according to the invention.
    Detailed Description of Preferred Embodiments In this specification, the word "bulk material" has a broad meaning which includes all moist or wet, solid, organic bulk materials in particulate form with a size distribution and particle density suitable for pneumatic transport. The particulate bulk materials include in particular biomass derived from plants and animals. Examples include residues and wastes from agriculture (steaks, straw, etc.), raw materials based on wood (wood chips, bark, sticks and wood shavings), residues from forestry; waste from sawmills (sawdust), peat, energy crops and waste from livestock farming (from dairy farms, pig farming and poultry farming). The particulate bulk materials also include biomass based on residues from the food industry. These particulate bulk materials typically have an initial water content of at least 40% water, by weight. Likewise, the word “steam” has a broad meaning that includes water vapor, an oxygen-free gaseous medium and mixtures thereof. Furthermore, the term “drying medium” has a broad meaning which includes dry, wet, saturated, heated or superheated steam and combinations thereof.
    Referring to Figure 1, there is shown a drying apparatus 1 for drying bulk material 9 according to an aspect of the invention, which comprises a heating section 2 and a drying section 3, interconnected so as to substantially form a closed conduit 4. When the dryer 1 is in operation, the closed circulation line 4 is filled with a heated drying medium 5, such as heated wet steam or superheated saturated steam, which provides an oxygen-free, inert internal environment which inhibits the risk of dust explosions. The closed circulation line 4 comprises lines and pipes for guiding bulk material, suspended in drying medium, between the elements of the drying apparatus.
    One purpose of the drying medium is to transfer heat energy into the bulk material, and another purpose of the drying medium is to guide bulk material through the drying section 3 from the feeder 6 to the separating means 8 by pneumatic transport.
    The drying section 3 comprises feed means 6, a drying space 7 and separating means 8. The feed means 6, such as an feeder, is connected to the line 4 for closed circulation downstream from the heating section 2 relative to the flow direction of the drying medium inside the line 4 for closed circulation. The feed means 6 introduces moist or wet bulk material 9 into the closed circulation line 4, where a flow of drying medium circulates. The input can be made semi-continuously or continuously. the feeder 6 is preferably a cell feeder, a plug screw feeder or a similar feed device which provides a marginal leakage of drying medium at the actual pressure difference, whereby it is adapted to avoid pressure losses from the line of the closed circulation dryer. A drying space 7, such as a drying line, a rotating drum or a fluidized bed, is connected to and located downstream of the feeder 6.
    The drying of the wet or moist bulk material 9 is done by mixing the bulk material and the heated drying medium 5 in the drying space 7, whereby heat energy is transferred from the heated drying medium to the particles of the bulk material. Moisture and volatile material in the particles of the wet bulk material 9 evaporate and form excess steam 10. The drying is carried out at steady state conditions, which means fully developed pneumatic transport of the bulk material 9 with the drying medium 5 through the drying space 7.
    The dried bulk material 9, suspended in the drying medium, is led in the closed circulation line 4 to separating means 8, which is connected to and located downstream of the drying space 7 in relation to the flow direction of the drying medium inside the closed circulation line. The separating means 8 comprises a plurality of cyclones, which can separate the dried bulk material from the drying medium in a single separation step.
    The separating means 8 are described in more detail in the following. The separated bulk material is discharged from the drying apparatus 1 via an outlet 11, and the drying medium is returned to the protection section 2.
    The heating section 2 comprises a fan 12, a heater 13 and an outlet 14 for excess steam. The fan 12 provides a flow of drying medium 5, the transferring steam, which circulates in the line 4 for closed circulation. A first end of the heater, designated 13a, is connected to the fan 12. The heater 13 indirectly heats or superheats the drying medium. The heater comprises a heat exchanger, and to it is supplied primarily heat from exhaust gases, steam under pressure, hot water, thermal oil or the like from a source of water. In particular, industrial processes using steam, such as a combined heat and power plant, a paper mill, a steam generating plant or the like, can supply heat to the dryer 1.
    A second end of the heater, denoted by 13b, is one with the drying section 3 in the closed circulation line 4. Furthermore, the heating section 2 comprises an outlet 14 for excess steam, which releases the excess steam 10 which evaporates from the particles in the bulk material during the drying process. In this way, the operating conditions, such as the pressure and the temperature, of the drying apparatus 1 can be regulated and maintained.
    The heating section 2 is connected to a downstream of the separating means 8 in relation to the flow direction of the drying medium inside the closed circulation line.
    Accordingly, only the drying medium is passed through the fan 12 and the heater 13. The bulk material 9 is passed only through the drying section 3 and passes outside the heating section 2. Since the temperature of the drying medium inside the heater 13 is well above the softening temperature of lignin, particles of the bulk material must be avoided led with the drying medium to the heater. The particles and from these derived materials, such as lignin and tar, can otherwise be easily released and deposited on the surfaces of the heating section 2 and in particular on the heat conducting surfaces of the heater 13. The efficiency of the heating means depends on the transfer of heat energy from the heat conducting surface of the heaters. heating means to the drying medium. If the heat-conducting surfaces are not clean, the transfer of thermal energy to the drying medium decreases.
    The excess steam outlet 14 is connected downstream of the separating means 8 in relation to the flow direction of the drying medium inside the closed circulation line. The excess steam 10 can be led to means 15 for energy recovery, such as a steam generator or condenser, as part of an energy recovery process. In the means for energy recovery, the excess steam is cooled and depleted of energy, whereby pure steam and waste condensate are formed. The waste condensate contains in particular condensed volatile material but may also contain suspended particles of bulk material which have not been separated from the drying medium by the separating agents 8. The suspended particles of bulk material in the waste condensate may give rise to contaminants such as biochemical oxygen demand (BOD) and chemical oxygen demand (COD), in the drain from the dryer. The environmental laws for wastewater from industries are becoming increasingly stricter and require careful monitoring and control of the levels of pollutants in industrial wastewater. However, since the separating means 8 have proved to be very effective, the environmental impact due to the drying apparatus and the drying process is very limited. A surprising effect of the separating means 8 used in the drying apparatus of the present invention is that in general no subsequent sewage treatment of the waste condensate is required, since the amount of suspended particles in the waste condensate is insignificant or at least well below the permissible limits.
    The dried bulk material discharged from the dryer 1 can be used for additional industrial purposes, for example as fuel in a combustion chamber in a combined heat and power plant or in the production of panels based on wood, such as MDF, or in the production of biofuel pellets for the consumer market.
    Especially when the source material is derived from wood or forest products, the energy content of the dried material is high, and it can be used for the production of biofuel pellets or used as fuel in a combined thermal power plant that primarily supplies the drying apparatus. By varying the pressure and temperature inside the drying apparatus 1 and by varying the volume of the wet bulk material supplied to the drying apparatus, different properties of the final product can be obtained. For example, the bulk material can be dried to a very low water content. If the dried bulk material is to be used in the production of biofuel pellets, the water content should be below 12% by weight. Another area of use for the dried bulk material is in the production of wood and polymer composites. In this case, the water content should be below 2% by weight, preferably below 1% by weight and preferably below 0.5% by weight. In the following, several variants of separating agents are described, each of which can be integrated in the drying apparatus described above. Furthermore, all identical details are denoted by the same reference numerals.
    Figure 1 further shows a first variant of the separating means 8. The separating means 8 comprise cyclones, a plurality of cyclones. This means that the separating means 8 comprise at least two cyclones. In the drying apparatus shown in Figure 1, the first variant of the separating means 8 comprises four cyclones 8a to 8d of uniform size and design. However, it is possible to vary the number of cyclones according to the volume and type of bulk material to be dried.
    The cyclones 8a-8d in the separating means 8 are connected via a common inlet 16 to the drying space 7. The cyclones 8a-8d are also connected via a common gas outlet 17 to the fan 12. The flow of suspended bulk material 9 and drying medium 5 is thus led from the drying space 7 via the common inlet 16 simultaneously to all the cyclones 8a-8d, and the drying medium 5 is delivered simultaneously from all the cyclones 8a-8d via a common gas outlet 17 to the fan 12. This gives the advantage that the separation of the bulk material 9 from the drying medium takes place before the drying medium is returned to the heating section. suspended particles could otherwise be deposited on the surfaces of the fan 12 and the heater 13.
    Cyclones 8a-8d are preferably connected in parallel via cyclone inlet lines 18a-18d to the common inlet 16. Furthermore, cyclones 8a-8d are preferably also connected in parallel via gas outlet lines 19a-19d to the common gas outlet 17.
    This fate of bulk material and drying medium is thus simultaneously distributed in the cyclones connected in parallel via the cyclone inlet lines 18a-18d, and the drying medium is discharged simultaneously from the cyclones connected in parallel via the gas outlet lines 19a-19d. A functional advantage of this is that the flow of bulk material and drying medium is divided between the cyclones, which means that each cyclone receives only a part of the entire flow.
    Consequently, the dimensions of the cyclones can be reduced, and the separation efficiency of the cyclones can be improved.
    The common inlet 16 comprises a vertical inlet segment 20a, and the cyclones 8a-8d are preferably arranged symmetrically around this vertical inlet segment 20a. The cyclones 8a to 8d are preferably arranged at the same distance from this vertical inlet segment 20a of the common inlet 16. A functional advantage of this is that a uniform distribution of the flow of bulk material and drying medium which is led into the cyclones can be obtained.
    The common inlet 16 is connected to each cyclone 8a-8d via a cyclone inlet line 18a-18d for distributing the flow of bulk material and drying medium into the cyclones. Preferably, each cyclone is connected to the vertical inlet segment 20a of the common inlet 16 via its own cyclone inlet conduit 18a-18d. Preferably, the cyclone inlet lines are as short as possible to limit the flow resistance, but the length of the cyclone inlet lines can be adapted to the circumstances. Preferably, all cyclone inlet conduits 18a-18d have the same cross-sectional area in order to obtain an equal flow volume through each respective cyclone.
    Figure 1 shows that the common inlet 16 comprises a U-shaped conduit 21, connected between the drying space 7 and the separating means 8. This U-shaped conduit 21 comprises two vertical segments 20a, 20b and a curved segment 20c which connect the vertical segments 20a, 20b at their lower end. One of the vertical segments 20a is located midway between the four cyclones 8a-8d. However, the common inlet 16 may alternatively comprise a conduit with a horizontal segment, a curved segment and a vertical segment, the horizontal segment being connected to the drying space 7 (not shown in the figure). In the drying apparatus shown in Figure 1, the first variant of the separating means 8 comprises four cyclones 8a-8d. In operation of the dryer comprising a separating means 8 with four cyclones 8a-8d, a quarter of the amount of suspended bulk material and drying medium is distributed in each cyclone 8a-8d. As previously mentioned, the separating means 8 can be designed with a different number of cyclones. The proportion of fl fate distributed in each cyclone varies correspondingly. For example, if the separating means 8 comprises five uniform cyclones, each cyclone receives one fifth of the flow.
    For a given total flow rate of the suspended bulk material and the drying medium, the pressure drop in each cyclone 8a-8d is smaller and the centrifugal force applied to the particles of the bulk material during the separation in the cyclones is greater than for the single prior art cyclone, since the size of each of the cyclones, width, diameter and height, can be reduced relative to the single cyclone in the prior art. The consequence of this is that although the separation can be carried out in only one step, the separation efficiency can be improved.
    Figure 3 shows a longitudinal section through the first variant of separating means 8. Figure 3 shows by means of an arrow that the flow of bulk material 9 and drying medium is pneumatically directed upwards in the vertical direction in the vertical inlet segment 20a of the common inlet 16 to the cyclone inlet lines. 18a-18d. By directing the suspended bulk material vertically upwards, towards gravity, by means of pneumatic transport, the distribution of the particles of the bulk material is improved, and a more even distribution of the particles in the drying medium is obtained. This gives the functional advantage that the particles of the bulk material are spread more evenly in the drying medium, and as a result a more even distribution is obtained in the cyclones 8a-8d. A uniform distribution of the bulk material and the drying medium fed to each of the cyclones can be obtained. The bulk material, suspended in drying medium, is passed through the common inlet 16 and distributed in portions in the cyclones 8a-8d via the cyclone inlet lines 18a-18d. The common inlet 16 includes a baffle 22 for diverting the suspended bulk material into the cyclone inlet conduits 18a-18d. Figure 3 also shows that each cyclone 8a-8d comprises a cyclone upper part 23, a separating cyclone part 24 and a collecting cyclone part 25. The cyclone upper part 23 has a cylindrical cross section. The cyclone inlet conduit 18a-18d is located perpendicular to the common inlet 16 and connected tangentially to the cyclone top 23 to tangentially introduce the flow of bulk material into the cyclone to provide efficient cyclone separation. Each collecting cyclone part 25 is connected to a central hopper 26 via outlet pipes 27.
    The cyclones are thus connected in parallel also to the central hopper. The dispenser 11 is connected to the central feed hopper 26 to dispense the separated dried bulk material from the dryer 1. The dispenser 11 is of a type similar to the feeder 6, which has been mentioned above.
    The common gas outlet 17 also comprises a vertical outlet segment 28, and the cyclones 8a-8d are preferably arranged symmetrically with respect to the vertical outlet segment 28 of the common gas outlet 17. Each cyclone 8a-8d is connected to the common gas outlet 17 via a gas outlet line. 19d to divert the separated drying medium 5 from each cyclone. These gas outlet conduits 19a-19d are preferably symmetrically located around the common gas outlet 17 and connected thereto.
    Preferably, each cyclone is connected to the common gas outlet 17 via a separate gas outlet line 19a-19d. The drying medium 5 is returned to the heating section 2 of the fan 12 and is passed on to the heater 13 to be reheated.
    Figures 1 and 3 also show a common conduit 29, located midway between the four cyclones 8a-8d, located at the same distance from the common conduit 29.
    This common conduit includes the common inlet 16 and the common gas outlet 17. The vertical inlet segment 20 of the common inlet 16 and the vertical outlet segment 28 of the common gas outlet 17 are connected and joined to form a single joined common conduit 29 with a separating cross-section To divide the common conduit into the common inlet 16 and the common gas outlet 17. The structural advantage of this is that a compact design is obtained and that the supporting structure of the common inlet and the common gas outlet is improved. Figure 3 shows the divider 30, which includes a divider inlet side 31 adjacent the common inlet 16 and a divider outlet side 32 adjacent the common gas outlet 17. The divider inlet side 31 includes a baffle 22 for diverting the flow of bulk material and drying medium into cyclone inlet lines. The divider 30 and the baffle 22 have flat surfaces, since the pressure on the divider inlet side 31 and on the divider outlet side 32 is almost identical.
    As mentioned above, the number of cyclones may vary in the separating means 8. For example, the separating means 8 may comprise two, three, four, five, six or more cyclones, connected in a manner corresponding to that described above. .
    Figure 2 shows a second variant of separating means 8 ', which differs from the previously described separating means 8 in that there is no direct connection between the common inlet 16 and the common gas outlet 17. Instead, the common inlet 16 and the the common gas outlet 17 independently of each other and arranged separately to enable a flexible placement of the cyclones. Figure 2 further shows a cyclones 8'a-8'd having the same properties and effects as cyclones 8a-8d in the previously described separating means 8. The conduit end 50 of the common inlet 16 is equipped with a baffle 22 ', directed towards the conduit. inside, to control the flow of suspended bulk material into the cyclones. In the separating means 8 ', the conduit end 50 and the baffle surface 22' may be flat or have a curved shape, for example hemispherical. This is particularly advantageous if there is a pressure difference between the inside and the outside of the line end 50.
    Apart from the above-mentioned differences, all other features of the second variant of separating means 8 'have the same properties and effects as corresponding features of the previously described separating means 8 and are therefore not described in more detail.
    Furthermore, the second variant of separating means 8 'can be connected to a drying apparatus 1 in a manner corresponding to that of the first separating means 8.
    The design of the separating means 8, 8 'and the number of cyclones may deviate from the embodiments described above without departing from the scope of the invention. The separating means 8 comprise at least two cyclones, and alternatively the separating means 8 may comprise three, four, five, six or more cyclones, connected in parallel to the common inlet 16 and connected in parallel to the common gas outlet 17. Figure 4a shows a schematic illustration of the first variant of three cyclone separating means 8a to 8c. Figure 4b shows another schematic illustration of the first variant of six cyclone separators 8a-8f. The separating means 8 'may also comprise, for example, two, three, four, five, six or more cyclones. As the person skilled in the art will readily realize, the cyclones can also be connected to the drying apparatus 8 'in the separating means 8' in a manner corresponding to that which has been described above. Adaptations of the drying apparatus 1 with respect to the racks and the interconnection depending on the number of cyclones fall within the scope of the invention. All types of indirectly heated dryers can be used, such as pneumatic dryers, fluidized bed dryers or rotary drum dryers. The drying apparatus 1 can be a pressurized steam dryer. Such a drying device can be operated over atmospheric pressure. Alternatively, the drying apparatus 1 can also be operated at atmospheric pressure or below atmospheric pressure. The advantage of the drying device being operated above atmospheric pressure is that the internal energy is utilized more efficiently in the process of utilizing energy. This means that the drying apparatus 1 is operated at a positive pressure in relation to the atmospheric pressure.
    The pressure range is generally 1 to 40 bar, preferably 2 to 15 bar, primarily 2 to 10 bar and most preferably 3 to 5 bar. Since the line 4 for closed circulation of the drying apparatus 1 is filled with pressurized steam, the oxygen content is insignificant, thereby eliminating the risk of dust explosions or fire. The possibility of utilizing the large heat source by utilizing the latent heat in the excess steam increases with temperature, i.e. with the pressure in the dryer 1. Furthermore, the heat capacity of the steam increases with increasing pressure, which makes it possible to reduce the size of the dryer.
    The drying apparatus 1 can be used for drying bulk materials based on wood, bulk materials based on agricultural products and all other materials mentioned in the description above.
    The heat energy from the drying apparatus 1 can be recovered in a process for recovering energy by depleting the excess steam 10 by indirect friend transfer to another medium in a means 15 for recovery, connected to the drying apparatus 1. Different means 15 for recovery can be used depending on the geographical the location of the dryer 1 but also depending on the purpose of the final dried product, other industrial processes associated with this, etc. In areas where district heating is available, the recovered heat can be used within such a network. The means for recovery may be, for example, a steam generator for condensing steam or a heat exchanger which produces low-pressure steam, whereby the low-pressure steam can be used in a low-pressure steam turbine to obtain electricity or a remote friend network. Another possibility is that the steam with lower pressure is discharged to an external industrial process, such as a sawmill or the like, where the steam can be used very efficiently, for example in plants for drying wood. These are different, non-limiting examples of recovery of heat from the dryer. If the recovery means is a vapor regenerator, combustible substances from the excess steam can be separated by condensation, after which the combustible substances are combusted in a combustion chamber. The heat generated during combustion can be recovered with a steam turbine and returned as primary heat to the dryer 1. However, other industrial applications are also possible, such as integration with a paper or pulp factory, chemical industry or heavy industry, such as the steel industry. In principle, all types of steam generating processes can be combined with the drying apparatus of the present invention.
    Figure 5 shows a schematic process diagram for an advantageous and energy-efficient combined friendly power plant (CHP) 36, which comprises a fuel factory 33 and the drying apparatus 1 according to the invention. The drying apparatus 1 is integrated in the fuel factory 33, which produces energy pellets from the dried bulk material. In addition to the drying apparatus, the fuel plant 33 also includes a steam generator 34, for example a steam fan exchanger, for converting the generated excess steam 10 into low pressure process steam and / or for producing district heating. The fuel plant 33 also includes a low pressure condensing turbine 35 for producing energy that can be conducted into the grid. A dryer of this type, usually a pressurized steam dryer, can have a production volume of more than 400 tonnes of bulk material per day (mainly wood shavings, sawdust and waste from forestry) and a flow rate of more than 20 m / s, which requires a lot large elements in the dryer.
    The combination of a combined heat and power plant and a fuel plant is particularly favorable, as some of the heat produced in the fuel plant can be supplied to the combined heat and power plant. The combined heat and power plant 36 comprises a combustion chamber 38 and a steam boiler 37 for steam generation. The steam formed is supplied to at least one turbine 39 to obtain electricity. The steam is led from the turbine 39 to a heat condenser 40, which can feed a remote protection network 41. Furthermore, the extracted steam from the turbine supplies the pressure apparatus 1 with a pressure between 5 and 40 bar with the primary heat required for drying bulk material with the indirect heating means. 13 in the dryer 1. This provides a very efficient combined energy plant that produces electricity, friend and fuel.
    权利要求:
    Claims (19)
    [1]
    A drying apparatus (1) for drying bulk material, comprising - a closed circulation line (4) adapted to be filled with a drying medium when the drying apparatus is in operation, - a fan (12) connected to the closed line. circulation to give a flow of drying medium, - heating means (13), connected to the fan (12) for indirectly heating the drying medium, - feed means (6), connected to the conduit (4) for closed circulation to lead bulk material into the closed circulation line (4), - a drying space (7), connected to the feed medium (6), where the bulk material is dried by transferring friendly energy from the drying medium, - an outlet (14) for excess steam, connected to the closed circulation line (4) to release excess steam (10), - separating means (8; 8 '), coupled to the drying space (7), for separating bulk material from the drying medium, characterized in that the separating means (8; 8') comprise a fl ertal cyclones (8a-8d; 8'a- 8'd).
    [2]
    Drying apparatus according to claim 1, wherein the cyclones (8a-8d; 8'a-8'd) are connected via a common inlet (16) to the drying space (7) and wherein the cyclones are connected via a common gas outlet (17) to the fan. (12).
    [3]
    Drying apparatus according to claim 1 or 2, wherein the cyclones (8a-8d; 8'a-8'd) are connected in parallel via cyclone inlet lines (18a-18d) to the common inlet (16).
    [4]
    Drying apparatus according to any one of the preceding claims, wherein the cyclones (8a-8d; 8'a-8'd) are connected in parallel via gas outlet lines (19a-19d) to the common gas outlet (17).
    [5]
    A drying apparatus according to any one of the preceding claims, wherein the common inlet (16) comprises a vertical inlet segment (20a) and the cyclones (8a-8d; 8'a-8'd) are symmetrically arranged around the vertical inlet segment (20a).
    [6]
    Drying apparatus according to any one of the preceding claims, wherein the common gas outlet (17) comprises a vertical outlet segment (28) and the cyclones (8a-8d; 8'a -8'd) are arranged symmetrically with respect to the vertical outlet segment ( In the common gas outlet (17).
    [7]
    Drying apparatus according to any one of the preceding claims, wherein the cyclones (8a -8d) are arranged at the same distance from the common inlet (16). 10 15 20 25 30 35 14
    [8]
    A drying apparatus according to any one of the preceding claims comprising a common conduit (29), the common conduit comprising the common inlet (16) and the common gas outlet (17).
    [9]
    The drying apparatus of claim 8, wherein the common conduit (29) comprises a divider (30) for dividing the common conduit (29) into the common inlet (16) and the common gas outlet (17).
    [10]
    A drying apparatus according to any one of the preceding claims, wherein the cyclones comprise at least two, three, four, five or six cyclones.
    [11]
    Drying apparatus according to any one of the preceding claims, wherein the drying apparatus (1) comprises a pressurized steam dryer operated above atmospheric pressure.
    [12]
    Combined thermal power plant (36), which comprises a drying apparatus (1) according to any one of the preceding claims.
    [13]
    A method for drying bulk material in a drying apparatus (1) according to any one of claims 1 to 11, which comprises a closed circulation conduit (4) filled with a drying medium when the drying apparatus is operated, which method comprises a flow of the drying medium is obtained by means of a fan (12) inside the conduit (4) for closed circulation, the drying medium is heated indirectly with heating means (13), bulk material is led by means of feed means (6) into a flow of the drying medium inside the closed circulation conduit. , the bulk material is dried in a drying space (7) by transferring heat energy from the heated drying medium to the bulk material, - excess steam (10) is released via an outlet (14) for excess steam from the closed circulation line, this method being characterized in that bulk material separated from the drying medium by a separating agent (8; 8 ') comprising a plurality of cyclones (8a-8d; 8'a-8'd).
    [14]
    A method according to claim 13, which comprises that a flow of bulk material and drying medium is led from the drying space (7) via a common inlet (16) to the cyclones (8a-8d; 8'a-8'd) and that the drying medium is discharged from the cyclones (8a-8d; 8'a-8'd) via a common gas outlet (17) to the fan (12).
    [15]
    A method according to claim 13 or 14, which comprises distributing the flow of bulk material and drying medium in parallel via cyclone inlet lines (18a-18d) to the cyclones (8a-8d; 8'a-8'd).
    [16]
    A method according to any one of claims 13 to 15, which comprises discharging the drying medium in parallel via gas outlet lines (19a-19d) from the cyclones (8a-8d). 15
    [17]
    A method according to any one of claims 13 to 16, which comprises leading the av of bulk material and drying medium upwards in a vertical direction in a vertical inlet segment (20a) in the common gas inlet (16).
    [18]
    Use of a drying apparatus (1) according to any one of claims 1 to 11 for drying bulk material based on wood.
    [19]
    Use of a drying apparatus (1) according to any one of claims 1 to 11 for drying bulk material based agricultural products.
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    公开号 | 公开日 | 专利标题
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    同族专利:
    公开号 | 公开日
    SE535059C2|2012-03-27|
    EP2480848A4|2014-10-08|
    EP2480848A1|2012-08-01|
    WO2011037519A1|2011-03-31|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US3720253A|1971-04-02|1973-03-13|Ballas Egg Prod Corp|Egg white spray drying apparatus and method|
    DE2360235A1|1973-12-04|1975-10-23|Hoechst Ag|METHOD OF DRYING SEWAGE SLUDGE|
    US4300291A|1979-03-13|1981-11-17|Salem Corporation|Methods and apparatus for heating particulate material|
    RO113659B1|1992-05-08|1998-09-30|Victoria Elect Commission|Carbonaceus fuel drying and gasification process, installation for applying the same and integrated process for producing energy from carbonaceus fuel|
    US5907910A|1997-04-24|1999-06-01|Fisher-Klosterman, Inc.|Method for cyclone conversion for a fluidized bed|
    FI111229B|2000-02-08|2003-06-30|Fortum Oyj|Method and apparatus for separating solids from gases|
    RU2331829C2|2001-12-17|2008-08-20|Хольм Кристенсен Байосистемер Апс|Facility for friable production drying by superheated steam|
    CN2559944Y|2002-08-26|2003-07-09|史文伟|Overheat steam circulating air dryer|
    FR2894842B1|2005-12-21|2008-02-01|Inst Francais Du Petrole|NEW SOLID GAS SEPARATION AND STRIPING SYSTEM FOR FLUIDIZED BED CATALYTIC CRACKING UNITS|
    EP2119387A1|2008-04-24|2009-11-18|Suzhou Clean Bloom Electric Co. Ltd|Cyclonic dust collecting apparatus and vacuum cleaner|SE535782C2|2011-03-21|2012-12-18|Skellefteaa Kraftaktiebolag|Process and system for the recovery of thermal energy from a steam dryer|
    CN102225385A|2011-04-07|2011-10-26|中国农业机械化科学研究院呼和浩特分院|Parallel cyclone water-sand separator|
    CN109489357B|2018-10-30|2021-01-29|中南林业科技大学|Combined multipurpose drying kiln for wood and using method thereof|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    SE0950692A|SE535059C2|2009-09-22|2009-09-22|Drying apparatus comprising a separation step with parallel coupled cyclones and method and use|SE0950692A| SE535059C2|2009-09-22|2009-09-22|Drying apparatus comprising a separation step with parallel coupled cyclones and method and use|
    PCT/SE2010/050975| WO2011037519A1|2009-09-22|2010-09-13|Drying apparatus and process for drying bulk material and use of said drying apparatus to dry bulk material.|
    EP10819113.1A| EP2480848A4|2009-09-22|2010-09-13|Drying apparatus and process for drying bulk material and use of said drying apparatus to dry bulk material.|
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