JP2015102255A - Hydrate solid drying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce energy consumption of a hydrate solid drying device.SOLUTION: A hydrate solid drying device includes: a preheating heat exchanger 11 preheating a hydrate solid using hot water and a gas medium as a heat source; a fluidized bed dryer 12 heating the preheated hydrate solid using compressed steam, evaporating water contained in the hydrate solid to separate the water as steam, and supplying a dried solid; a heat-recovery heat exchanger 15 cooling the dried solid using the gas medium as a cold source, and recovering heat; and a gas compressor 16 increasing a temperature of the gas medium recovering the heat by compressing the gas. The heated gas medium is supplied together with hot water formed by condensing the compressed steam in the fluidized bed dryer 12 to the preheating heat exchanger 11. The preheating heat exchanger 11 and the heat-recovery heat exchanger 15 are counterflow heat exchangers.

Description

  The present invention relates to a hydrated solid material drying apparatus.

  DESCRIPTION OF RELATED ART Conventionally, the hydrated solid drying apparatus which heats and dries hydrated solids, such as peat, lignite, and biomass, and provides as a dried product is provided.

  For example, in Patent Documents 1 and 2 below, a hydrated solid is heated to a predetermined temperature with a heat exchanger for primary drying, and then the hydrated solid formed in a fluidized bed with a dryer is heated with a heat transfer tube. A drying apparatus is disclosed that evaporates moisture, cools it with a radiant heat exchanger, and provides it as a dry solid.

  In this drying apparatus, the heat transfer tube is supplied with a mixed gas fluid obtained by adding a vaporized gas, which is vaporized from a hydrated solid, to a fluidized gas such as air that has formed a fluidized bed in a dryer. In the heat transfer tube, water vapor in the mixed gas fluid releases latent heat and condenses, and the mixed gas becomes a mixed fluid of fluidized gas and water.

  This mixed fluid is provided as a heat medium to the primary drying heat exchanger. On the other hand, the hydrated solid material dried in the dryer is sent to a heat-dissipating heat exchanger, dissipates heat to the mixed gas supplied to the dryer, and is cooled and provided.

  In the conventional water-containing solids drying apparatus, a primary drying heat exchanger that heats the water-containing solids to a predetermined temperature and a heat release that cools the dried water-containing solids by releasing heat together with a dryer that dries the water-containing solids. A fluidized bed heat exchanger was also used as the heat exchanger.

JP 2012-154605 A JP 2010-276259 A

  In the water-containing solid material drying apparatus, it is required to increase the thermal efficiency when drying the water-containing solid material and reduce the energy consumption.

  This application is proposed in view of the above-described circumstances, and an object thereof is to provide a water-containing solid material drying device that has improved thermal efficiency and reduced energy consumption.

  In order to solve the above-mentioned problem, the invention of the water-containing solid material drying apparatus according to the present invention is supplied with water-containing solid material, hot water and a gaseous medium, and heats the water-containing solid material using the warm water and the gaseous medium as heat sources, A preheating heat exchanger that preheats until water contained in the water-containing solid material starts to evaporate, the water-containing solid material preheated in the preheating heat exchanger, and water vapor after compression are supplied, and the water vapor after compression is used as a heat source The water-containing solid is heated, the water contained in the water-containing solid is evaporated to form water vapor, the water is separated from the water-containing solid and dried to obtain a solid, and dried in the dryer A heat recovery heat exchanger that is supplied with the solid matter and a gaseous medium, cools the solid matter using the gaseous medium as a cooling source, and recovers heat from the solid matter to the gaseous medium; and the heat recovery heat exchange The heat was recovered by the vessel A gas compressor supplied with the gas medium and heating the gas medium by compression, steam is recovered from the dryer, and at least a part of the steam is heated as a post-compression steam that has been heated by compression. Supplyed to a dryer, at least a part of the compressed water vapor supplied to the dryer is condensed into warm water, and is supplied to the preheating heat exchanger together with the gaseous medium heated by the gas compressor. The preheating heat exchanger and the heat recovery heat exchanger are countercurrent heat exchangers.

  The countercurrent heat exchanger may be a countercurrent indirect heat exchanger. The countercurrent heat exchanger may be a countercurrent direct heat exchanger. The countercurrent heat exchanger may be a rotary countercurrent heat exchanger or a moving bed countercurrent heat exchanger.

  The dryer forms a fluidized state of the fluidized bed of the hydrated solid with the steam and heats the hydrated solid in the fluidized bed with the steam after compression as a heat source and is contained in the hydrated solid. It is also possible to use a fluidized bed dryer that evaporates the water to be water vapor and separates the water from the hydrated solid to obtain a dried solid.

  A blower for supplying a part of the water vapor recovered from the fluidized bed dryer to the fluidized bed dryer; and the compressed water vapor obtained by compressing the remainder of the water vapor recovered from the fluidized bed dryer by compression. A steam compressor to be supplied to the dryer, the fluidized bed dryer further includes a heat transfer tube, and the compressed steam is supplied to the heat transfer tube, dissipates heat through the heat transfer tube, and is condensed. You may make it become warm water.

  The dryer may be a countercurrent heat exchanger. The countercurrent heat exchanger may be a countercurrent indirect heat exchanger or a countercurrent direct heat exchanger.

  The preheating heat exchanger may further include a pressure recovery turbine that is supplied with the gaseous medium preheated with the hydrated solid and is driven by the pressure of the gaseous medium. A power recovery mechanism that supplies power recovered by the pressure recovery turbine to the gas compressor may be further included. The power recovery mechanism may connect the gas compressor and the pressure recovery turbine coaxially.

  According to the present invention, since the countercurrent heat exchanger is used for the preheating heat exchanger and the heat recovery heat exchanger, the heat efficiency of the heat exchange with the water-containing solid can be increased, thereby reducing the energy consumption. Can do. Moreover, since heat is recovered from the solid material dried by the heat recovery heat exchanger and reused for preheating in the preheating heat exchanger, energy consumption can be further reduced.

It is a block diagram which shows embodiment of a drying apparatus. It is a block diagram which shows the modification 1 of a drying apparatus. It is a block diagram which shows the modification 2 of a drying apparatus. It is a block diagram which shows the modification 3 of a drying apparatus. It is a block diagram which shows the modification 4 of a drying apparatus. It is a block diagram which shows the comparative example of a drying apparatus. It is a figure which shows the energy consumption of the drying apparatus of this Embodiment, and the drying apparatus of a comparative example.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of a water-containing solid material drying apparatus according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing a configuration of a drying apparatus according to an embodiment of the present invention. The drying apparatus according to this embodiment converts the hydrated solid material into a dried product, and reduces energy consumption by recovering and reusing both latent heat and sensible heat supplied to the hydrated solid material in the process. To do.

  The water-containing solids to be treated by this drying apparatus include sludge, lignite, and biomass, and the biomass includes, but is not limited to, wheat, sesame, and rice. Moreover, in the following description of the drying apparatus, temperatures are exemplified in relation to components and the like, but these temperatures are merely examples, and are not limited to these.

  This drying apparatus preheats a water-containing solid material supplied as a raw material to be dried, a preheating heat exchanger 11, and evaporates water contained in the water-containing solid material preheated by the preheating heat exchanger 11, thereby A fluidized bed dryer 12 that is a solid material and a heat recovery heat exchanger 15 that recovers heat from the solid material supplied from the fluidized bed dryer 12 are provided. The preheating heat exchanger 11 and the heat recovery heat exchanger 15 are rotary countercurrent indirect heat exchangers.

  In addition, the drying apparatus supplies a part of the steam recovered from the fluidized bed dryer 12 to the fluidized bed dryer 12 to ensure the fluidized state of the fluidized bed, and insulates the remainder of the recovered steam. A vapor compressor 13 is supplied to the fluidized bed dryer 12 as water vapor after compression by compression.

  Furthermore, this drying apparatus was supplied from the gas compressor 16 and the preheating heat exchanger 11 that supply the preheating heat exchanger 11 by heating the gaseous medium whose heat has been recovered by the heat recovery heat exchanger 15 by adiabatic compression. A pressure recovery turbine 17 driven by the pressure of the gas medium, and a power recovery mechanism 18 for supplying the power recovered by the pressure recovery turbine 17 to the gas compressor 16 are provided.

  The preheating heat exchanger 11 is supplied with water-containing solid at 30 ° C. at room temperature. In the preheating heat exchanger 11, the 30 ° C. water-containing solid absorbs heat using the 110 ° C. hot water supplied from the fluidized bed dryer 12 and the 110 ° C. gas medium supplied from the gas compressor 16 as a heat source. The water contained in the solid is heated to 100 ° C. at which evaporation begins.

  The 110 ° C. hot water supplied to the preheating heat exchanger 11 is dissipated and cooled down to 45 ° C. and discharged as waste water. Similarly, the 110 ° C. gaseous medium also dissipated and lowered to 45 ° C. to recover pressure. It is sent to the turbine 17.

  FIG. 2 is a diagram showing an outline of a rotary counter-current indirect heat exchanger used in the preheating heat exchanger 11 of this embodiment. This counter-current indirect heat exchanger has a cylindrical body 21 for storing an object 101 for heat exchange, which is installed inclined from a horizontal direction and is driven to rotate around an axis P. A heat transfer tube 22 facing in the direction of the axis P is provided inside. A fluid heat medium is supplied to the heat transfer tube 22 from the lower end 26 of the body 21 toward the upper end 25. In addition, this countercurrent indirect heat exchanger may be called a rotary type or a rotary drum type.

  The countercurrent indirect heat exchanger is charged with a solid hydrated solid, which is the object 101, from one end 25 at the upper part, and the hydrated solid is directed toward the other end 26 at the lower part of the body 21 as the body 21 rotates. It is conveyed while being stirred. The water-containing solid is indirectly heated by the fluid heat medium flowing in the heat transfer tube 22 in the direction opposite to the direction in which the water-containing solid travels while being transported through the body 21.

  In this countercurrent indirect heat exchanger, a mixed fluid in which the supplied hot water of 110 ° C. and a gaseous medium of 110 ° C. are mixed is used as the fluid of the heat medium. The mixed fluid at 110 ° C. dissipates heat to the water-containing solid matter through the heat transfer tube 22 and is cooled down to 45 ° C. and discharged. The 45 ° C. mixed fluid is separated into a gas component and a liquid component, the gas component is sent to the pressure recovery turbine 17 as a gaseous medium, and the liquid component is discharged as waste water.

  The water-containing solid heated to 100 ° C. in the preheating heat exchanger 11 is supplied to the fluidized bed dryer 12. In the fluidized bed dryer 12, a part of 100 ° C. water vapor recovered from the fluidized bed dryer 12 forms a fluidized state of the fluidized bed of water-containing solids in the fluidized bed dryer 12 by the blower 14. Has been supplied for. The remainder of the recovered steam is supplied to a heat transfer tube disposed in the fluidized bed dryer 12 as compressed steam at 150 ° C. adiabatically compressed by the steam compressor 13.

  In the fluidized bed dryer 12, the 100 ° C. water-containing solid supplied from the preheating heat exchanger 11 is formed in the fluidized bed by the 100 ° C. water vapor supplied from the blower 14, and the water-containing solid in a fluidized state is After compression at 150 ° C. through the heat transfer tube, the steam is heated using the steam as a heat source. And the water contained in this hydrous solid substance evaporates, and is isolate | separated as water vapor | steam, and it is set as a solid body of a 100 degreeC dry body.

  The 100 ° C. water vapor supplied from the blower 14 to the fluidized bed dryer 12 is collected together with the 100 ° C. water vapor evaporated from the water-containing solids in the fluidized bed dryer 12 and sent to the steam compressor 13 and the blower 14. The 150 ° C. water vapor supplied from the steam compressor 13 to the heat transfer tube of the fluidized bed dryer 12 dissipates heat in the heat transfer tube, condenses into 110 ° C. warm water, and is sent to the preheating heat exchanger 11.

  The solid material at 100 ° C. dried by the fluidized bed dryer 12 is supplied to the heat recovery heat exchanger 15. In the heat recovery heat exchanger 15, the solid at 100 ° C. is cooled by using a gaseous medium such as air at 30 ° C. at room temperature as a cold heat source to dissipate heat, and the temperature is lowered to 40 degrees near the room temperature. And it provides from this drying apparatus as a solid substance of a final dry body.

  As the heat recovery heat exchanger 15 of this embodiment, a rotary countercurrent indirect heat exchanger as shown in FIG. The countercurrent indirect heat exchanger is charged with a solid solid material, which is the object 101, from one end 25 at the upper part, and the solid substance is stirred toward the other end 26 at the lower part as the body 21 rotates. It is conveyed while. The solid matter is cooled by the gaseous medium of the fluid flowing in the heat transfer tube 22 in the direction opposite to the direction in which the solid matter proceeds while being transported in the body 21.

  In this countercurrent indirect heat exchanger, the gas medium at 30 ° C. absorbs heat from the solid at 100 ° C. through the heat transfer tube 22, and is heated to 90 ° C. and discharged. On the other hand, the solid material at 100 ° C. supplied to the countercurrent indirect heat exchanger is provided after being cooled to 40 ° C.

  The gaseous medium that has absorbed heat in the heat recovery heat exchanger 15 and has been heated to 90 ° C. is sent to the gas compressor 16. In the gas compressor 16, the 90 ° C. gaseous medium supplied from the heat recovery heat exchanger 15 is adiabatically compressed, heated to 110 ° C., and sent to the preheating heat exchanger 11.

  The 110 ° C. gaseous medium sent to the preheating heat exchanger 11 releases heat to 45 ° C. and is sent to the pressure recovery turbine 17. In the pressure recovery turbine 17, the gaseous medium drives the pressure recovery turbine 17 by adiabatic expansion and is discharged as exhaust gas that has been cooled to 35 ° C.

  The pressure recovery turbine 17 is connected to the gas compressor 16 by a power recovery mechanism 18. The gas compressor 16 is driven by the power recovered by the pressure recovery turbine 17 through the power recovery mechanism 18. The power recovery mechanism 18 may connect both the pressure recovery turbine 17 and the gas compressor 16 on the same axis, but is not limited thereto. The power recovery mechanism 18 may be any suitable mechanism that can drive the pressure recovery turbine 17 by the recovered power obtained by the pressure recovery turbine 17.

  In the drying apparatus of this embodiment, a rotary countercurrent indirect heat exchanger is used for the preheating heat exchanger 11 and the heat recovery heat exchanger 15. Since this rotary counter-current indirect heat exchanger has a high heat exchange efficiency, it is possible to improve the heat efficiency and reduce the energy consumption of the preheating heat exchanger 11 and the heat recovery heat exchanger 15 and to dry the heat exchanger. It is possible to improve the thermal efficiency of the entire apparatus and reduce the energy consumption.

  In this drying apparatus, the water vapor discharged from the fluidized bed dryer 12 is adiabatically compressed and supplied to the fluidized bed dryer 12 by supplying compressed water vapor as a heat source to the fluidized bed dryer 12 so that it is contained in the hydrated solid matter. The latent heat absorbed when water evaporates is reused as latent heat supplied to evaporate the water content of the water-containing solid. The compressed water vapor supplied as a heat source to the fluidized bed dryer 12 has a larger heat capacity than a gas such as air, and can increase the heat efficiency of heat exchange and thus reduce energy consumption.

  Further, in this drying apparatus, the heat recovery heat exchanger 15 recovers the gaseous medium recovered from the heat by adiabatic compression and supplies it as a heat source of the preheating heat exchanger 11. The sensible heat of the hydrated solid is reused for the sensible heat supplied to preheat the hydrated solid in the preheating heat exchanger 11. Furthermore, the hot water supplied from the fluidized bed dryer 12 is used as a heat source for the preheating heat exchanger 11, and the gas medium supplied from the preheating heat exchanger 11 is recovered as power by the pressure recovery turbine 17 to generate heat. We are trying to reuse.

  As described above, in this drying apparatus, a rotary counter-current indirect heat exchanger having high heat exchange efficiency is adopted for the preheating heat exchanger 11 and the heat recovery heat exchanger 15, and steam recompression, hot water heat is used. Heat is recovered and reused in each step of recovery, dry body heat recovery, and gas medium compression. Therefore, in this drying apparatus, reduction of energy consumption is achieved with improvement in thermal efficiency.

(Modification 1)
This modified example 1 is a moving bed type countercurrent indirect heat exchanger in place of the rotary countercurrent indirect heat exchanger in the preheating heat exchanger 11 and the heat recovery heat exchanger 15 of the drying apparatus of this embodiment. Is adopted. Since the other configurations excluding the preheating heat exchanger 11 and the heat recovery heat exchanger 15 and the temperatures of the respective parts are the same as in this embodiment, the description thereof is omitted.

  FIG. 3 is a diagram showing an outline of a moving bed type countercurrent indirect heat exchanger. This countercurrent indirect heat exchanger has a cylindrical body 31 extending in the vertical direction for storing the object 101 for heat exchange, and a heat transfer tube 32 oriented in the vertical direction is provided inside the body 31. ing. A fluid heat medium is supplied to the heat transfer tube 32 from the lower end 36 to the upper end 35 of the body 31.

  When this counter-current indirect heat exchanger is used as the preheating heat exchanger 11, a solid hydrated solid as the object 101 is introduced from the upper end 35, and the hydrated solid is placed inside the body 31 from the lower end 36 to the upper end. Stack up to nearly 35. A predetermined proportion of the hydrated solid in the body 31 is discharged from the lower end 36 at a predetermined speed, and accordingly, the hydrated solid is moved at a predetermined speed toward the lower end 36 toward the body 31. The water-containing solid is indirectly heated by the fluid heat medium flowing in the heat transfer tube 32 in the direction opposite to the direction in which the water-containing solid travels while moving in the body 31.

  When this countercurrent indirect heat exchanger is used as the heat recovery heat exchanger 15, the solid material as the object 101 is introduced from the upper end 35, and the solid material moves through the body 31 while passing through the heat transfer tube 32. The fluid flowing in the direction opposite to the direction in which the hydrated solid material travels is indirectly cooled as a cooling medium.

  The moving bed type countercurrent indirect heat exchanger of the first modification has high heat exchange efficiency as compared with, for example, a conventional fluidized bed heat exchanger. Therefore, it is possible to improve the thermal efficiency of the preheating heat exchanger 11 and the heat recovery heat exchanger 15, and consequently to improve the thermal efficiency of the drying apparatus of the first modification and reduce the energy consumption.

  The moving bed type countercurrent indirect heat exchanger of Modification 1 requires a larger amount of energy to move the object 101 than the rotary type countercurrent indirect heat exchanger. Therefore, the energy consumption of this modification 1 is larger than the energy consumption of this embodiment.

(Modification 2)
In this modified example 2, in the preheating heat exchanger 11 and the heat recovery heat exchanger 15 of the drying apparatus of this embodiment, a rotary countercurrent direct heat exchanger is used instead of the rotary countercurrent indirect heat exchanger. Adopted. Since the other configurations excluding the preheating heat exchanger 11 and the heat recovery heat exchanger 15 and the temperatures of the respective parts are the same as in this embodiment, the description thereof is omitted.

  FIG. 4 is a diagram showing an outline of a rotary counter-current direct heat exchanger. This counter-current direct heat exchanger has a horizontally installed cylindrical body 41 for storing an object 101 for heat exchange, and a screw feeder that is rotationally driven inside the body 41 is provided. A heat transfer tube is provided on the shaft 42 of the screw feeder to enable heat exchange via the blades 43 of the screw. The heat transfer tube is supplied with a liquid heat medium from the other end 46 of the body 41 toward the one end 45. Further, a gaseous heat medium is supplied from the other end 46 of the body 41 toward the one end 45. In addition, this counterflow direct heat exchanger may be called a rotary type or a screw feeder type.

  When this counter-current direct heat exchanger is used as the preheating heat exchanger 11, a solid hydrated solid material as the object 101 is introduced from one end 45, and the hydrated solid material passes through the body 41 by the rotation of the screw feeder. It is conveyed toward the other end 46 while being stirred. The water-containing solids are indirectly transferred through the heat transfer tubes by the hot water of the liquid flowing in the direction opposite to the direction in which the water-containing solids travel through the heat transfer tube provided on the shaft 42 of the screw feeder while being conveyed in the body 41. And heated directly by the gaseous medium flowing in the opposite direction in the body 41 as well.

  When this countercurrent direct heat exchanger is used as the heat recovery heat exchanger 15, a solid solid material as the object 101 is introduced from one end 45, and the solid material is conveyed while being transported through the body 41. The gas medium flowing in the direction opposite to the direction in which the water-containing solid material proceeds in 41 is directly cooled as a cooling medium. In the heat recovery heat exchanger 15, since a liquid heat medium is not used, it is not necessary to provide a heat transfer tube on the shaft 42 of the screw feeder.

  The rotary counter-current direct heat exchanger according to Modification 2 has high heat exchange efficiency as compared with, for example, a conventional fluidized bed heat exchanger. Therefore, it is possible to improve the thermal efficiency of the preheating heat exchanger 11 and the heat recovery heat exchanger 15, and consequently improve the thermal efficiency of the drying device of the second modification and reduce the energy consumption.

  This rotary counter-current direct heat exchanger is different from the rotary counter-current indirect heat exchanger of this embodiment, because the hydrated solid or solid is in direct contact with the gaseous heat medium, Exchange efficiency can be achieved. On the other hand, in the preheating heat exchanger 11, it is necessary to manage the humidity so that the vapor generated from the hydrated solid does not enter the gaseous medium discharged from the preheating heat exchanger 11.

(Modification 3)
This modification 3 is a moving bed type countercurrent direct heat exchanger in place of the rotary countercurrent indirect heat exchanger in the preheating heat exchanger 11 and the heat recovery heat exchanger 15 of the drying apparatus of this embodiment. Is adopted. Since the other configurations excluding the preheating heat exchanger 11 and the heat recovery heat exchanger 15 and the temperatures of the respective parts are the same as in this embodiment, the description thereof is omitted.

  FIG. 5 is a diagram showing an outline of a moving bed type countercurrent direct heat exchanger. This counter-current direct heat exchanger has a cylindrical body 51 extending in the vertical direction in which an object 101 for heat exchange is stored. In this counterflow direct heat exchanger, a fluid heat medium is supplied into the body 51 from the lower end 56 toward the upper end 55.

  When this countercurrent direct heat exchanger is used as the preheating heat exchanger 11, a solid hydrated solid as the object 101 is introduced from the upper end 55, and the hydrated solid is introduced into the body 51 from the lower end 56 to the upper end. Stack up to near 55. A predetermined percentage of the hydrated solid in the body 51 is discharged from the lower end 56 at a predetermined speed, and the hydrated solid is moved at a predetermined speed toward the lower end 56 along the body 51. The water-containing solid is directly heated by the fluid heat medium flowing in the body 51 in the direction opposite to the direction in which the water-containing solid travels while moving in the body 51.

  When the countercurrent direct heat exchanger is used as the heat recovery heat exchanger 15, a solid solid material as the object 101 is introduced from the upper end 55, and the solid material moves while moving through the body 51. The fluid flowing in the direction opposite to the direction in which the water-containing solids travel in 51 is directly cooled as a cooling medium.

  The moving bed type countercurrent direct heat exchanger of the third modification has high heat exchange efficiency as compared with, for example, a conventional fluidized bed heat exchanger. Therefore, it is possible to improve the thermal efficiency of the preheating heat exchanger 11 and the heat recovery heat exchanger 15 and, consequently, the thermal efficiency of the drying device of this modification 3 and reduce the energy consumption.

  The moving bed type countercurrent direct heat exchanger of Modification 3 requires a larger amount of energy to move the object 101 and the like than the rotary type countercurrent indirect heat exchanger. Therefore, the energy consumption of Modification 3 is greater than the energy consumption of this embodiment.

  Unlike the moving bed type countercurrent indirect heat exchanger of this embodiment, this moving bed type countercurrent direct heat exchanger is in direct contact with the fluid heat medium because the hydrated solids or solids are in direct contact with the fluid heat medium. High heat exchange efficiency can be achieved. On the other hand, in the preheating heat exchanger 11, it is necessary to manage the humidity so that the vapor generated from the hydrated solid does not enter the gaseous medium discharged from the preheating heat exchanger 11.

  In this embodiment and Modifications 1 to 3, the preheating heat exchanger 11 and the heat recovery heat exchanger 15 include a rotary countercurrent indirect heat exchanger, a moving bed type countercurrent indirect heat exchanger, a rotation The same type of counter-current heat exchanger is adopted among the counter-current direct heat exchanger of the type and the moving-bed type counter-current direct heat exchanger, but it is not limited to the same combination. The preheating heat exchanger 11 and the heat recovery heat exchanger 15 include a rotary countercurrent indirect heat exchanger, a moving bed type countercurrent indirect heat exchanger, a rotary countercurrent direct heat exchanger, and a moving bed type. Different types of counter-current heat exchangers can be employed instead of the counter-current direct heat exchanger.

  Moreover, in this embodiment and the modifications 1-3, a rotary countercurrent indirect heat exchanger, a moving bed type countercurrent indirect heat exchanger, a rotary countercurrent direct heat exchanger, a moving bed type Although the counterflow direct heat exchanger was illustrated, the heat exchanger which can be used for the preheating heat exchanger 11 and the heat recovery heat exchanger 15 is not limited thereto. Even if it is not a rotary type or a moving bed type, it can be used if it is a countercurrent direct heat exchanger or a countercurrent indirect heat exchanger.

  Furthermore, in this Embodiment and the modifications 1-3, although the fluidized bed dryer 12 was used, it is not limited to this. Instead of the fluidized bed dryer 12, a rotary or moving bed type countercurrent direct heat exchanger or countercurrent indirect heat exchanger may be used. Moreover, it is not restricted to these, If it is a countercurrent direct heat exchanger or a countercurrent indirect heat exchanger, it can be used.

(Comparative example)
In this comparative example, in the preheating heat exchanger 11 and the heat recovery heat exchanger 15 of the drying apparatus according to this embodiment, a fluidized bed heat exchanger is employed instead of the rotary countercurrent indirect heat exchanger. . Since the other configurations excluding the preheating heat exchanger 11 and the heat recovery heat exchanger 15 and the temperatures of the respective parts are the same as in this embodiment, the description thereof is omitted.

  FIG. 6 is a diagram showing an outline of a fluidized bed heat exchanger. This moving bed heat exchanger stores an object 101 in a container 61 provided with a heat transfer tube 62 for supplying a liquid heat medium, and supplies a gaseous heat medium from a pipe 63 at the bottom of the container 61 to thereby detect the object. 101 is formed in a fluidized fluidized bed. Then, heat exchange can be performed directly between the fluidized object 101 and the gas heat medium, and heat exchange can be performed indirectly between the object 101 and the liquid medium flowing through the heat transfer pipe 62. I do.

  When this fluidized bed heat exchanger is used as the preheating heat exchanger 11, a solid hydrated solid is stored in the container 61 as the object 101, and this hydrated solid is a gas supplied from a pipe 63 at the bottom. A fluidized bed is formed by the medium and heated directly by the gaseous medium. At the same time, the water-containing solid material in the fluidized state is indirectly heated by the hot water via the heat transfer tube 62.

  When this fluidized bed heat exchanger is used as the heat recovery heat exchanger 15, a solid hydrated solid is stored in the container 61 as the object 101, and the hydrated solid is supplied from a pipe 63 at the bottom. A fluidized bed is formed by the gaseous medium and is cooled directly by the gaseous medium. In the heat recovery heat exchanger 15, since no liquid heat medium is used, it is not necessary to provide the heat transfer tube 62 in the container 61.

  In the fluidized bed heat exchanger, since the object 101 formed in the fluidized fluidized bed and the heat medium exchange heat directly or through the heat transfer pipe 62, heat exchange efficiency is high. However, a large amount of energy is required to form the object 101 in the fluidized bed, which may cause a decrease in thermal efficiency and an increase in energy consumption.

(Contrast of embodiment and comparative example)
FIG. 7 is a diagram comparing the energy consumption of this embodiment, Modifications 1 to 3 and Comparative Example. In the figure, the case of the comparative example which employ | adopted the fluidized-bed heat exchanger as the preheating heat exchanger 11 and the heat recovery heat exchanger 15 was made into 100% as a reference value of energy consumption.

  The energy consumption of this embodiment, which employs a rotary or moving bed type countercurrent direct heat exchanger or countercurrent indirect heat exchanger, and variations 1 to 3, was approximately 30%. In other words, by adopting a rotary or moving bed type countercurrent direct heat exchanger or countercurrent indirect heat exchanger instead of the fluidized bed heat exchanger in the preheating heat exchanger 11 and the heat recovery heat exchanger 15, It has become possible to reduce energy consumption by almost 70%.

11 Preheating Heat Exchanger 12 Fluidized Bed Dryer 13 Steam Compressor 14 Blower 15 Heat Recovery Heat Exchanger 16 Gas Compressor 17 Pressure Recovery Turbine 18 Power Recovery Mechanism

Claims (11)

A preheat heat exchanger that is supplied with hydrous solids, hot water and a gaseous medium, heats the hydrous solids using the hot water and the gaseous medium as a heat source, and preheats until the water contained in the hydrous solids starts to evaporate;
The water-containing solids preheated by the preheating heat exchanger and the steam after compression are supplied, the water-containing solids are heated using the water vapor after compression as a heat source, and the water contained in the water-containing solids is evaporated to steam. And a drier that separates water from the hydrated solid to form a dried solid,
A heat recovery heat exchanger that is supplied with the solid matter dried by the dryer and a gaseous medium, cools the solid matter using the gaseous medium as a cold heat source, and recovers heat from the solid matter to the gaseous medium. When,
A gas compressor that is supplied with the gaseous medium from which heat has been recovered by the heat recovery heat exchanger and raises the temperature of the gaseous medium by compression; and
Steam is recovered from the dryer, at least a portion of which is supplied to the dryer as compressed steam whose temperature has been raised by compression, and at least a portion of the compressed steam supplied to the dryer Is condensed into warm water, and is supplied to the preheating heat exchanger together with the gaseous medium heated by the gas compressor,
The said preheating heat exchanger and the said heat | fever recovery heat exchanger are the water-containing solid substance drying apparatuses which are countercurrent heat exchangers.   The hydrous solid matter drying apparatus according to claim 1, wherein the countercurrent heat exchanger is a countercurrent indirect heat exchanger.   The water-containing solid matter drying device according to claim 1, wherein the countercurrent heat exchanger is a countercurrent direct heat exchanger.   The hydrated solid matter drying device according to claim 2 or 3, wherein the countercurrent heat exchanger is a rotary countercurrent heat exchanger or a moving bed type countercurrent heat exchanger.   The dryer forms a fluidized state of the fluidized bed of the hydrated solid with the steam and heats the hydrated solid in the fluidized bed with the steam after compression as a heat source and is contained in the hydrated solid. The water-containing solid material drying apparatus according to any one of claims 1 to 4, wherein the water-containing solid material drying apparatus is a fluidized bed drier that separates water from the water-containing solid material to dry the water. A blower for supplying a part of the steam recovered from the fluidized bed dryer to the fluidized bed dryer;
A steam compressor that supplies post-compression steam to the fluidized bed dryer, the temperature of the remaining steam recovered from the fluidized bed dryer being increased by compression, and
The hydrous solid matter drying apparatus according to claim 5, wherein the fluidized bed dryer further includes a heat transfer tube, and the compressed water vapor is supplied to the heat transfer tube, dissipates heat through the heat transfer tube, and condenses to become hot water. .   The water-containing solid matter drying apparatus according to any one of claims 1 to 4, wherein the dryer is a countercurrent heat exchanger.   The hydrous solid matter drying apparatus according to claim 7, wherein the countercurrent heat exchanger is a countercurrent indirect heat exchanger or a countercurrent direct heat exchanger.   The water content according to any one of claims 1 to 8, further comprising a pressure recovery turbine that is supplied with the gaseous medium preheated with the preheated heat exchanger and driven by the pressure of the gaseous medium. Solid matter drying equipment.   The water-containing solid material drying device according to claim 9, further comprising a power recovery mechanism that supplies power recovered by the pressure recovery turbine to the gas compressor.   The water-containing solid matter drying device according to claim 10, wherein the power recovery mechanism connects the gas compressor and the pressure recovery turbine on the same axis.

Images