DRYING TREATMENT DEVICE

Abstract

A drying treatment apparatus includes: a casing having a loading port for loading crushed pieces and a discharge port for discharging the crushed pieces; a screw conveyor including a screw impeller provided in an interior of the casing and a driving device that drives the screw impeller, the screw conveyor conveying the loaded crushed pieces through the loading port to the discharge port using an ejection action of the screw impeller; and a heater that heats the casing. In the drying treatment apparatus, the driving device drives the screw impeller, while the heater heats the casing.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention

[0001] The present disclosure relates to a technique that performs a drying treatment on crushed pieces of batteries containing an electrolyte so that the electrolyte evaporates. 2. Description of the state of the art

[0002] Japanese Patent Application Laid-Open No. 2023-052213 (JP 2023-052213 A) discloses a technique relating to a method for treating used lithium-ion batteries. JP 2023-052213 A discloses the method for treating lithium-ion batteries, which includes a step of performing a drying treatment on crushed pieces (crushed material) of lithium-ion batteries and a step of conveying the dried crushed pieces to a transport container using a conveyor.

[0003] In addition, examples of the documents showing the prior art in the technical field to which the present disclosure relates include Japanese Patent Application Laid-Open No. 8-117719, Japanese Patent Application Laid-Open No. 2003-200146, and Japanese Patent Application Laid-Open No. 2002-273400. OVERVIEW OF THE INVENTION

[0004] As disclosed in JP 2023-052213 A, there is a method including a step of performing a drying treatment to remove an electrolyte contained in crushed pieces of batteries as a method for treating used batteries. The drying treatment is a treatment that requires a considerable amount of time because sufficient removal of the electrolyte is required. Thus, in such a treatment method, a step of performing a drying treatment and a step of performing conveyance to the next treatment step can become rate-limiting processes. An object of the present disclosure is to provide a technique that enables step shortening in a treatment method including a step of performing a drying treatment.

[0005] One aspect of the present disclosure relates to a drying treatment apparatus that evaporates an electrolyte contained in crushed pieces of batteries. The drying treatment apparatus includes: a casing having a loading port for loading the crushed pieces and a discharging port for discharging the crushed pieces; a screw conveyor including a screw impeller provided in an interior of the casing and a driving device that drives the screw impeller, the screw conveyor conveying the loaded crushed pieces through the loading port to the discharging port using an ejection action of the screw impeller; and a heater that heats the casing. In the drying treatment apparatus, the driving device drives the screw impeller, while the heater heats the casing.

[0006] According to the present disclosure, the drying treatment apparatus can convey the crushed pieces loaded into the casing from the loading port to the unloading port while performing the drying treatment to evaporate the electrolyte from the crushed pieces. Accordingly, the drying treatment step and the conveying step can be integrated together. As a result, it is possible to achieve effective step reduction in the treatment process including the drying treatment step. BRIEF DESCRIPTION OF THE CHARACTERS

[0007] Features, advantages and technical and industrial significance of exemplary embodiments of the invention are described below with reference to the accompanying drawings, in which like reference numerals designate like elements, and wherein: Fig. 1 is a diagram showing the configuration of a drying treatment apparatus according to an embodiment; Fig. 2 is a diagram illustrating the operation of the drying treatment apparatus according to the embodiment based on the Fig. 1 shown configuration; and Fig. 3 is a diagram describing a configuration for efficiently heating a casing in the drying treatment apparatus according to the embodiment. DETAILED DESCRIPTION OF EMBODIMENTS

[0008] An embodiment of the present disclosure will be described below with reference to the drawings. Note that like or corresponding parts in the drawings are denoted by like reference numerals to simplify or omit the description thereof. 1. Overview

[0009] Used batteries are treated through various treatment steps for the purpose of recycling or disposal. In particular, the treatment of used batteries requires proper removal and collection of an electrolyte contained in the batteries. For this purpose, as a method for treating used batteries, there is a treatment method including a treatment step (drying treatment step) of drying crushed pieces of crushed batteries to evaporate an electrolyte contained in the crushed pieces. The drying treatment step involves keeping the crushed pieces of the batteries in an atmosphere having a temperature and pressure that correspond to electrolyte evaporation conditions. The present embodiment relates to a drying treatment apparatus for performing the drying treatment step.

[0010] When switching from one treatment step to the next, an object to be treated is typically transported from a treatment device for one treatment step to a treatment device for the next treatment step. This means that between the treatment steps, there is typically a step (conveying step) for conveying the object to be treated.

[0011] A drying treatment apparatus according to the present embodiment makes it possible to integrate a drying treatment step and a conveying step into a treatment process including the drying treatment step. The drying treatment step is a treatment step that requires a considerable amount of time to sufficiently remove the electrolyte. Thus, integrating the drying treatment step and the conveying step together effectively shortens the steps in the entire treatment. The drying treatment apparatus according to the present embodiment will be described in detail below. 2. Drying treatment device

[0012] Fig. 1 is a diagram showing the configuration of a drying treatment apparatus 10 according to the present embodiment. Fig. Fig. 2 shows the operation of the drying treatment apparatus 10 according to the present embodiment based on the Fig. 1 shown configuration.

[0013] The drying treatment apparatus 10 according to the present embodiment includes a housing 100, a heater 200, a pressure reducing pump 300, an electrolyte collecting device 400, and a screw conveyor 500.

[0014] The casing 100 is provided with a screw blade 510 of the screw conveyor 500, which will be described later, in its interior and has a shape that extends in the axial direction of the screw blade 510. The casing 100 is formed, for example, from a steel material having high thermal conductivity. In particular, a part of the interior of the casing 100 may be curved downward to obtain sufficient pressure resistance. In particular, the interior may be formed such that, when the casing 100 is cut in a direction perpendicular to the axial direction of the screw blade 510, a bottom wall surface and left and right side wall surfaces defining the interior have a U-shape. Fig. 1 and Fig. 2 show side views of the housing 100 illustrating the interior. In fact, a ceiling wall surface is provided that defines the interior. Additionally, Fig. 1 and Fig. 2 shows a housing in which the housing 100 is installed in an inclined state. However, in the drying treatment apparatus 10 according to the present embodiment, the installation state of the housing 100 can be changed as needed.

[0015] The housing 100 has a loading opening 110 and a discharging opening 120. The loading opening 110 and the discharging opening 120 are provided at the respective positions near opposite ends of the screw flight 510. In Fig. 1 and Fig. 2, the loading port 110 is provided on a front surface of the housing 100 at the left end of the screw flight 510. The discharge port 120 is provided on a lower surface of the housing 100 at the right end of the screw flight 510. The positions of the loading port 110 and the discharge port 120 can be changed as needed.

[0016] Crushed pieces 1 of batteries containing an electrolyte are loaded into the housing 100 through the loading opening 110. The crushed pieces 1 are obtained, for example, by crushing the batteries in a frozen state in a previous treatment step. Examples of the battery to be crushed include a lithium-ion battery, a nickel-metal hydride battery, and a nickel battery. To facilitate loading the crushed pieces 1, a funnel may be connected to the loading opening 110.

[0017] The crushed pieces 1 loaded into the casing 100 are the object to be treated by the drying treatment device 10. In the drying treatment device 10, the heater 200 and the pressure reducing pump 300 are driven to perform a drying treatment to evaporate the electrolyte from the crushed pieces 1.

[0018] The heater 200 heats the housing 100. The structure of the heater 200 is not limited to any specific structure. For example, the heater 200 includes a heating wire. The heater 200 is driven so that the temperature inside the housing 100 rises to a certain temperature that corresponds to the electrolyte evaporation conditions.

[0019] The pressure reducing pump 300 is connected to the interior of the housing 100 through a pipe 20a and a pipe 20b. Note that the electrolyte collecting device 400 is provided between the housing 100 and the pressure reducing pump 300. The action of the electrolyte collecting device 400 will be described below.

[0020] The pressure reducing pump 300 is a pump that reduces the pressure inside the housing 100. The pressure reducing pump 300 can also be referred to as a "vacuum pump." The pressure reducing pump 300 draws air from the housing 100 through the pipe 20a and the pipe 20b to reduce the pressure inside the housing 100. The pressure reducing pump 300 is driven to reduce the pressure inside the housing 100 to a certain pressure that corresponds to the electrolyte evaporation conditions, while the heater 200 heats the housing 100.

[0021] The heating performed by the heater 200 and the pressure reduction performed by the pressure reducing pump 300 maintain the interior of the housing 100 at the temperature and pressure that cause the electrolyte contained in the crushed pieces 1 to evaporate. Thus, the electrolyte gradually evaporates from the crushed pieces 1 as the temperature of the crushed pieces 1 loaded into the housing 100 rises to the maintained temperature. In this way, the drying treatment for evaporating the electrolyte contained in the crushed pieces 1 is performed in the drying treatment device 10.

[0022] In the drying treatment device 10, the electrolyte removed from the crushed pieces 1 by the drying treatment is further collected by the action of the electrolyte collecting device 400.

[0023] The electrolyte collection device 400 is connected to the pipe 20a and the pipe 20b and is provided between the casing 100 and the pressure-reducing pump 300. The electrolyte 2a vaporized by the drying treatment in a gaseous state flows into the electrolyte collection device 400 through the pipe 20a by the pressure-reducing pump 300, which draws in air. The electrolyte collection device 400 is maintained at a temperature and pressure that cause the electrolyte 2a to condense into a gaseous state. That is, the electrolyte collection device 400 condenses the flowed-in electrolyte 2a into a gaseous state. The electrolyte collection device 400 then collects the condensed electrolyte 2b. In this way, the drying treatment device 10 can collect the electrolyte removed from the crushed pieces 1 by the drying treatment.

[0024] In the drying treatment device 10, the screw conveyor 500 further conveys the crushed pieces 1 from the loading opening 110 to the discharging opening 120 during the drying treatment of the crushed pieces 1.

[0025] The screw conveyor 500 includes the screw impeller 510 and a drive device 520. The screw impeller 510 is provided inside the housing 100 and is rotatable about an axis. The screw impeller 510 is formed, for example, from a steel material that has high thermal conductivity like the housing 100. The drive device 520 drives the screw impeller 510. The drive device 520 is, for example, an electric motor mounted to rotate the screw impeller 510 about the axis.

[0026] When the drive device 520 drives the screw impeller 510, the screw impeller 510 acts to expel the crushed pieces 1 in the interior of the housing 100 in the axial direction. The screw conveyor 500 conveys the crushed pieces 1 from the loading opening 110 to the discharge opening 120 using this ejection action of the screw impeller 510.

[0027] In the present embodiment, in particular, a shaftless screw conveyor can be used as the screw conveyor 500. That is, the screw impeller 510 is formed without a shaft. Each of the crushed pieces 1 loaded into the casing 100 may have a certain degree of grain size, and the grain sizes of the crushed pieces 1 may differ from each other. In such a case, the shaftless screw conveyor 500 makes it possible to prevent the crushed pieces 1 from becoming entangled with the screw impeller 510 while conveying the crushed pieces 1 and performing smooth conveying. However, depending on the degree of grain sizes of the crushed pieces 1, a shaft-type screw conveyor may be used as the screw conveyor 500.

[0028] In the drying treatment apparatus 10, the drive device 520 drives the screw impeller 510 while the heater 200 heats the casing 100. Accordingly, the crushed pieces 1 are conveyed from the loading port 110 to the discharging port 120 while undergoing the drying treatment. The drive device 520 can be controlled by a control device (not shown) to ensure that the drying treatment of the crushed pieces 1 is sufficiently performed during conveying. For example, the control device controls the drive device 520 to adjust the rotation speed of the screw impeller 510 so that the conveying time satisfies the treatment time of the drying treatment. In addition, for example, the control device controls the drive device 520 to adjust the rotation speed of the screw impeller 510 in accordance with the amount of electrolyte collected by the electrolyte collection device 400.

[0029] The crushed pieces 1 conveyed while undergoing the drying treatment are discharged from the housing 100 through the discharge opening 120. Thus, in the drying treatment apparatus 10, the crushed pieces 1 are conveyed from the loading opening 110 to the discharge opening 120 during the drying treatment of the crushed pieces 1.

[0030] As described above, in the drying treatment apparatus 10, the casing 100 in which the drying treatment is performed on the crushed pieces 1 also serves as a conveying path from the loading port 110 to the unloading port 120. Thus, the drying treatment apparatus 10 can perform the drying treatment step and can also perform the conveying step from the previous treatment step to the next treatment step. For example, the loading port 110 may be connected to a discharge port of a treatment device for the previous treatment step, and the unloading port 120 may be connected to a loading port of a treatment device for the next treatment step. In this way, according to the drying treatment apparatus 10 of the present embodiment, the drying treatment step and the conveying step can be integrated together.As a result, in the treatment process including the drying treatment step, it is possible to achieve an effective step shortening in the entire treatment.

[0031] In the drying treatment apparatus 10 of the present embodiment, the drying treatment is performed by heating the crushed pieces 1 to the specified temperature in the interior of the casing 100, which is maintained at a specified temperature. However, since the interior of the casing 100 is under reduced pressure, a sufficient temperature rise cannot be achieved solely by heating the crushed pieces 1 in the atmosphere. Thus, a configuration for more efficiently heating the crushed pieces 1 in the drying treatment apparatus 10 according to the present embodiment is proposed below. 3. Configuration for efficient heating of crushed pieces

[0032] Fig. 3 is a diagram describing the configuration for efficiently heating the crushed pieces 1 in the interior of the housing 100. Fig. 3 is a sectional view of the casing 100 taken in a direction perpendicular to the axial direction of the screw flight 510, and also a sectional view of the casing 100 viewed from the front of the loading opening 110.

[0033] First of all, in the Fig. 3, the heater 200 is configured to heat an outer wall surface 101 of the housing 100 extending in the axial direction of the screw flight 510 (the conveying direction of the screw conveyor 500). For example, the heater 200 includes a heating wire installed over the entire outer wall surface 101 of the housing 100.

[0034] Next is in the Fig. 3, the lower wall surface forming an inner wall surface 102 of the housing 100 is convexly curved toward the lower side of the housing 100, so that the lower wall surface and the left and right side wall surfaces forming the inner wall surface 102 have a U-shape in cross section. An outer edge portion of the screw blade 510 is configured to be in contact with the lower wall surface. Fig. 3, a lower part of the outer edge portion of the screw blade 510 is in contact with the curved portion of the lower wall surface.

[0035] The entire wall surface extending in the axial direction of the screw blade 510 of the casing 100 is heated by the heater 200. Since the outer edge portion of the screw blade 510 is in contact with the curved portion of the bottom wall surface, heat is efficiently transferred from the casing 100. As a result, the screw blade 510 is brought into a state heated to a temperature approximately equal to the temperature of the casing 100.

[0036] In this way, according to the Fig. 3, the entire outer wall surface 101 of the casing 100 is heated by the heater 200 in the axial direction of the screw blade 510. Since the outer edge portion of the screw blade 510 is in contact with the curved portion of the lower wall surface, the screw blade 510 is additionally heated to a temperature approximately equal to the temperature of the casing 100. Accordingly, the crushed pieces 1 in the interior of the casing 100 are heated by both the casing 100 and the screw blade 510, which serve as heat sources between the loading opening 110 and the unloading opening 120. In this way, according to the configuration described with reference to Fig. 3, it is possible to efficiently heat the crushed pieces 1.

[0037] To heat the crushed pieces 1 more efficiently, the casing 100 may be configured such that the distance between the crushed pieces 1 and the inner wall surface 102 of the casing 100 is a certain distance or less. Heat transfer to the crushed pieces 1 may become weaker as the distance from the inner wall surface 102 of the casing 100 increases. Thus, the configuration in which the distance between the crushed pieces 1 and the inner wall surface 102 is the certain distance or less makes it possible to prevent some of the crushed pieces 1 from becoming insufficiently heated. It is assumed that the crushed pieces 1 are located below the center of the screw blade 510 in the interior of the casing 100 due to the action of the screw blade 510.Thus, this configuration can be achieved by reducing a distance d1 (the distance in the vertical direction from the center of the screw flight 510 to the bottom surface of the housing 100) and a distance d2 (the distance in the horizontal direction from the center of the screw flight 510 to the side surface of the housing 100) shown in . Fig. 3, to a certain distance or less. For example, the housing 100 is configured so that each of the distances d1 and d2 is 100 mm or less. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2023-052213

[0002] JP 2023-052213 A [0002, 0004] JP 8-117719

[0003] JP 2003-200146

[0003] JP 2002-273400

[0003]

Claims

[1] A drying treatment apparatus that evaporates an electrolyte contained in crushed battery pieces, the drying treatment apparatus comprising: a housing having a loading opening for loading the crushed pieces and a discharge opening for discharging the crushed pieces; a screw conveyor comprising a screw blade provided in an interior space of the housing and a drive device driving the screw blade, the screw conveyor conveying the crushed pieces loaded through the loading opening to the discharge opening by utilizing an ejection action of the screw blade; and a heater that heats the housing, whereby the drive device drives the screw impeller while the heater heats the housing. [2] The drying treatment apparatus according to claim 1, further comprising a pressure reducing pump connected to the casing and reducing the pressure in the interior space, the pressure reducing pump being driven while the heater heats the casing. [3] The drying treatment apparatus according to claim 2, further comprising an electrolyte collecting device provided between the casing and the pressure reducing pump, which condenses and collects the electrolyte in a gaseous state. [4] Drying treatment apparatus according to one of claims 1 to 3, wherein an inner wall surface of the housing defining the interior space, comprising a lower wall surface which is convexly curved towards a lower side of the housing, the heater is configured to heat an outer wall surface of the housing extending in an axial direction of the screw flight, and an outer edge portion of the screw flight is configured to be in contact with a curved portion of the lower wall surface. [5] The drying treatment apparatus according to any one of claims 1 to 3, wherein the screw conveyor is a shaftless screw conveyor.

Images