Desalination Drying Systems and Processes

Abstract

To provide a desalination drying system and process capable of easily and efficiently producing high-quality, versatile dried products from processed raw materials, mainly shells, with salt removed. [Solution] The system includes a boiling and leaching section (40) that adds water to sand-like material, which is made by crushing the raw material, mainly shells, into sand beforehand, and boils it to leach the salt contained in the sand into high-temperature boiled water; a separation section (50) that separates the desalted sand-like material from which the salt has been leached from the sand-like material and salt-leached water containing salt; a recovery section (60) that coagulates residues mixed in the salt-leached water and recovers them as sediment; and a drying section (80) that heats the mixture of desalted sand-like material and sediment and evaporates the water remaining in the mixture.

Description

[Technical Field]

[0001] The present invention relates to a desalination and drying system and process for removing salt from processed raw materials, primarily shells, and then drying them to produce a dried product. [Background technology]

[0002] Conventionally, the large quantities of shells such as scallops generated in the fishing industry have been treated as industrial waste at great expense, as they have been deemed to have little usable value. The main component of these shells is calcium carbonate, and there has been a desire to develop a technology to effectively utilize them. For example, Patent Document 1 discloses a technology that makes it easy to remove shellfish and efficiently recycles shell waste as a raw material for cement.

[0003] However, shells contain a lot of salts, such as sodium chloride, due to the influence of seawater, so it is important to remove the salt when using them as a cement raw material. In other words, if a cement raw material contains salt, it will promote corrosion of metal materials, such as reinforcing bars, when they are buried in concrete after the cement has solidified. This has resulted in a problem in that the use of shells as a cement raw material is extremely limited. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-56426 Summary of the Invention [Problem to be solved by the invention]

[0005] However, while the prior art described in Patent Document 1 points out the importance of removing salt from shells, it does not disclose any specific countermeasures. In other words, in the prior art described in Patent Document 1, it was obvious to those skilled in the art that salt cannot be sufficiently removed from shells by draining the collected shells after discharging them into a storage section, or by simply showering the shells whose particle size has been adjusted.

[0006] The present invention was made in response to the problems of the prior art as described above, and aims to provide a desalination and drying system and process that can easily and efficiently produce high-quality, versatile dried products from processed raw materials, mainly seashells, from which salt has been removed, thereby further promoting the effective use of industrial waste and reducing waste disposal costs and environmental impact. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, one aspect of the present invention is to provide a method for manufacturing a semiconductor device comprising: A desalination and drying system for removing salt from a raw material to be processed, mainly consisting of shells, and then drying the raw material to produce a dried product, comprising: a boiling and elution unit that adds water to sand-like material obtained by crushing the raw material to be processed into sand and boils the material to elute salts contained in the sand into high-temperature boiling water; a separation unit that separates desalted sand obtained by eluting salt from the sand and salt-eluted water containing salt; a recovery unit that aggregates residues contained in the salt-eluted water and recovers them as precipitates; and a drying section for heating the mixture of the desalted sand and the precipitate to evaporate the water remaining in the mixture to obtain the dried product. [Effects of the Invention]

[0008] The desalination and drying system and process of the present invention can easily and efficiently produce high-quality, versatile dried products from processed raw materials, mainly shells, with salt removed, thereby further promoting the effective use of industrial waste and reducing waste disposal costs and environmental impact. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is an explanatory diagram illustrating an overall configuration of a desalination drying system according to an embodiment of the present invention. [Figure 2] FIG. 1 is a flow chart showing the processing flow of the desalting and drying process according to the present embodiment. [Figure 3] FIG. 2 is an explanatory diagram showing the state of the raw material being treated by the boiling leaching section (drying section) according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, a representative embodiment of the present invention will be described with reference to the drawings. The desalination and drying system 10 and process according to this embodiment were developed as a method for removing salt from shellfish, taking advantage of the property that salt dissolves easily in high-temperature water, and produce a dried product by removing salt from the raw material, which is primarily shells. Here, the raw material to be processed mainly refers to shells in general, but the following explanation will be given using scallop shells as the raw material to be processed and producing a dried product.

[0011] <Outline of Desalination Drying System 10> As shown in Figure 1, the desalting and drying system 10 of this embodiment basically comprises a boiling and leaching section 40, which adds water to sand-like material, which is made by crushing the raw material to be processed into sand, and boils it to dissolve the salt contained in the sand-like material into high-temperature boiled water; a separation section 50, which separates the desalted sand-like material from which the salt has been leached and the salt-containing leaching water; a recovery section 60, which coagulates any residue contained in the salt-containing leaching water and recovers it as a precipitate; and a drying section 80, which heats the mixture of the desalted sand-like material and the precipitate and evaporates the water remaining in the mixture to produce a dried product.

[0012] The desalination and drying system 10 according to this embodiment is equipped with a crushing section 20 that crushes the raw material to be processed in two stages to produce sand-like material, as well as a raw material storage tank 30, a mixing storage tank 70, a product storage tank 90, and a product hopper 93. Note that the components, shapes, numerical values, etc. shown in the embodiment described below are examples of the present invention and do not limit the present invention. Furthermore, detailed descriptions of already well-known matters and redundant descriptions of substantially identical configurations may be omitted as appropriate.

[0013] <About the crushing unit 20> The crushing unit 20 crushes scallop shells (the raw material to be processed) into sand-like material in advance. In this embodiment, for example, the crushing unit 20 is configured to crush scallop shells in two stages, combining a coarse crusher 21 that first crushes the raw material to be processed into coarsely crushed material with a coarse particle size, and a fine crusher 22 that then crushes the coarsely crushed material into finer particle size to produce sand-like material. However, the crushing unit 20 is not an essential component of the desalination and drying system 10, and may be an external component, and processing in this system 10 may begin with scallop shells that have been pre-processed into sand-like material externally.

[0014] The crusher 21 is not particularly limited in type, and an existing one can be appropriately selected and used. A commonly known crusher 21 has, for example, a configuration in which a pair of rollers 211 with uneven outer peripheries are arranged on the left and right sides in the middle of a hopper 210. With a crusher 21 having such a configuration, the raw material to be processed is sandwiched between the rollers 211 that rotate relative to each other and crushed. Here, the maximum particle size of the crushed material is a design factor that can be determined appropriately, and can be specifically adjusted by the crusher 21.

[0015] The coarsely crushed material crushed by the coarse crusher 21 is passed through a sieve 212 with specified openings, and is separated into coarsely crushed material that does not fall through the sieve 212 and sand-like material that does. The coarsely crushed material remaining on the sieve 212 is transported to the fine crusher 22 by a coarsely crushed material conveyor 213. Meanwhile, the sand-like material that falls through the sieve 212 is transported by a sand-like material conveyor 214, where it is mixed with the sand-like material from the fine crusher 22 and transported together to the raw material storage tank 30. The coarse crusher 21 may also be equipped with a washing function that allows water to flow in and removes any meat residue or debris adhering to the scallop shells with running water.

[0016] The type of the pulverizer 22 is not particularly limited, and an existing one can be appropriately selected and used. A commonly known pulverizer 22 has, for example, a configuration in which a drum 221 with scraping blades on its outer periphery is rotatably arranged below a tank 220. With the pulverizer 22, the coarsely crushed material is repeatedly scraped up and naturally falls as the drum 221 rotates, and is further crushed into fine sand-like material. Here, the maximum particle size of the sand-like material is a design factor that can be appropriately determined, but specifically, for example, a range of 0.5 mm to 2.5 mm is preferable, and the openings of the sieve 212 can be selected accordingly.

[0017] The sandy material crushed into fine particles by the fine crusher 22 is transported by the sandy material conveyor 214 to the raw material storage tank 30 together with the sandy material that has fallen through the sieve 212. There are no particular restrictions on the types of the coarsely crushed material conveyor 213 and the sandy material conveyor 214, but in this embodiment, for example, each is configured by a screw rotatably arranged along a predetermined path. The outlet of the coarsely crushed material conveyor 213 communicates with the upper part of the peripheral wall of the tank 220 in the fine crusher 22. The outlet of the sandy material conveyor 214 communicates with the upper part of the peripheral wall of the raw material storage tank 30, which will be described next.

[0018] <About the raw material storage tank 30> The raw material storage tank 30 is configured, for example, in the shape of a tank, and temporarily stores a predetermined amount of sand to be supplied to the boiling and leaching section 40. A rotatable screw 31 forming a conveyor is provided on the bottom of the raw material storage tank 30. However, the raw material storage tank 30 is not an essential component of the desalting and drying system 10; instead, the system 10 may be configured as an external component, and processing may begin with supplying sand from outside to the boiling and leaching section 40, which will be described below.

[0019] A delivery section 32 for delivering sand to the outside is provided near the bottom of the peripheral wall of the raw material storage tank 30. The delivery section 32 is connected to the upper part of the peripheral wall of the boiling tank 41 in the boiling and leaching section 40 described below, and the terminal end of the screw 31 is inserted into the delivery section 32. In the raw material storage tank 30, the amount of sand supplied to the boiling and leaching section 40 can be adjusted by controlling the rotation of the screw 31.

[0020] <About the boiling elution part 40> The boiling and leaching unit 40 adds water to the sand-like material whose surface area has been increased by crushing the shells in the crushing unit 20, boils it, and desalinates the sand-like material by leaching the salt in the sand-like material into the high-temperature boiling water. In this embodiment, the boiling and leaching unit 40 utilizes a drying device originally developed by the applicant and called a cyclone dryer. That is, the boiling and leaching unit 40 has a vertical cylindrical shape and includes a boiling tank 41 into which water is introduced along with the sand-like material processed in the crushing unit 20, and a rotating winding blade 410 attached to a rotating shaft 401 extending along a substantially vertical centerline within the boiling tank 41.

[0021] The boiling tank 41 is made of metal and has a vertical cylindrical shape. The boiling tank 41 is placed on the floor with its centerline perpendicular by a number of legs 42 attached to the underside of its bottom. The inner wall of the boiling tank 41 serves as a heat transfer surface 43 that transfers heat from the heating means to the hydrated sand. The heating means here comprises, for example, a jacket 44 formed to surround the outer periphery of the boiling tank 41, and a boiler (not shown) connected to this jacket 44 so as to communicate with it and that sends, for example, steam as a heat medium into the jacket 44.

[0022] The jacket 44 is provided with an inlet portion 44a that introduces the heat medium into the jacket 44 and an outlet portion (not shown) that discharges the heat medium to the outside of the jacket 44. As another example of the heating means, hot air may be fed into the jacket 44 instead of steam, or the jacket 44 may be composed of a heat medium contained in the jacket 44 and an electric heater disposed on the outer periphery of the jacket 44. In other words, heat from the electric heater is transferred to the heat transfer surface 43 via the heat medium.

[0023] There are various configurations for supplying sand and water into the boiling tank 41 and for discharging the desalted sand and salt-eluted water to the outside after boiling, but specifically, for example, the discharge section 32 of the raw material storage tank 30 is connected to the upper part of the peripheral wall of the boiling tank 41. The supply of sand from the discharge section 32 is regulated by the rotational drive of the screw 31 described above. Water is supplied to the boiling and eluting section 40 as needed through a water addition port or the like provided on the top surface of the boiling tank 41, but water may also be added in advance while the sand is stored in the raw material storage tank 30. The water supplied to the boiling and eluting section 40 (or the raw material storage tank 30) may be heated in advance.

[0024] Meanwhile, a boiling discharge outlet 45 for discharging the desalted sand and salt eluted water to the outside is provided on the peripheral wall of the boiling tank 41 below the communication port of the delivery section 32. The boiling discharge outlet 45 is formed, for example, as a tubular connection port with a larger diameter than the delivery section 32, and is configured to be able to open and close by an electromagnetic valve driven by a solenoid or the like. The boiling discharge outlet 45 is connected to the separation section 50, which will be described later, and the desalted sand and salt eluted water discharged from the boiling discharge outlet 45 are configured to be sent directly to the separation section 50, which will be described later.

[0025] A rotating shaft 401 extending along the vertical centerline of the boiling tank 41 is disposed inside the boiling tank 41. The rotating shaft 401 is journaled while passing through the centers of the top and bottom surfaces of the boiling tank 41. The upper end of the rotating shaft 401 is connected to an electric motor 402 disposed above the top surface of the boiling tank 41 so as to be capable of transmitting power. Meanwhile, the lower end of the rotating shaft 401 is rotatably supported by a bearing 403 disposed below the bottom surface of the boiling tank 41.

[0026] Rotary shaft 401 is provided with rotary winding blades 410. Rotary shaft 401 is driven to rotate by electric motor 402, and rotary winding blades 410 are configured to rotate in synchronization with rotary shaft 401. Note that electric motor 402 may be configured to be disposed below the bottom surface instead of above the top surface. Rotary shaft 401 may also be configured to connect multiple rotary shafts aligned vertically on the same axis.

[0027] In this embodiment, the rotary winding blades 410 are provided in a single vertical row below the rotary shaft 401. However, the specific number and arrangement of the rotary winding blades 410 are not limited to those shown in Fig. 1 and are design factors that can be determined appropriately depending on the height and dimensions of the boiling tank 41. For example, the rotary shaft 401 may be provided with two or more rotary winding blades 410, 410... arranged in multiple vertical rows.

[0028] The rotary winding blade 410 includes multiple base blades 411 arranged circumferentially around the rotary shaft 401; in this embodiment, for example, three base blades 411 are included. The base blades 411 are formed to be identical to each other and are arranged, for example, with a phase shift of approximately 120 degrees. Each base blade 411 is supported so as to extend continuously from the tip of an arm 412 whose base end is attached to the rotary shaft 401. Here, the arm 412 may be considered to be part of the configuration of the base blade 411. Note that when multiple stages of rotary winding blades 410 are provided, the number and length of the base blades 411 may be changed for each rotary winding blade 410.

[0029] Each base blade 411 extends in a circumferential direction around the rotation axis 401 in a plan view, and has a flat surface 411a (see FIG. 3) that can carry sandy material from its starting end connected to the tip of the arm 412 and move it to its terminal end while winding it up. The flat surface 411a of each base blade 411 is formed so as to extend obliquely upward from its starting end to its terminal end in the direction opposite to the rotation direction R (see FIG. 1).

[0030] That is, each base blade 411 is configured to place and roll up sand-like material on its flat surface 411a, and press the material into a thin film against the heat transfer surface 43 of the boiling tank 41 by centrifugal force P (see FIG. 3) and inertial force. Here, the flat surface 411a extends with a constant width up to a length within a 360-degree circumferential range in a plan view, and the outer circumferential edge of the flat surface 411a is formed in an arc shape that follows the cylindrical shape of the heat transfer surface 43. A clearance U that allows rotation of each base blade 411 is provided between the outer circumferential edge of the flat surface 411a and the heat transfer surface 43.

[0031] In this boiling and leaching unit 40, the sand-like material fed into the boiling tank 41 has a large contact area with the high-temperature boiled water added with water due to the heat transfer surface 43, causing the shell tissue to expand, and as the rotating winding blades 410 rotate, the sand-like material is repeatedly pushed up and down as a thin film against the heat transfer surface 43, as described above. As a result, the hydrated sand-like material is heated, causing friction and rubbing against itself, and is thoroughly cooked by the boiling phenomenon. Therefore, the salt contained in the sand-like material is leached into the high-temperature boiled water and is thoroughly desalinated.

[0032] <Regarding the separation unit 50> The separation section 50 separates the desalted sand obtained by eluting salt from the sand by the boiling elution section 40 from salt elution water containing salt. In this embodiment, the separation section 50 is configured, for example, by placing a substantially cylindrical screen 51 at an incline and inserting a screw 52 inside the screen 51 to pump the desalted sand against the incline. In the separation section 50, the mixture of desalted sand and salt elution water from the boiling elution section 40 flows into the screen 51 from the lower end, and the salt elution water is separated in the process of pumping the desalted sand by the rotation of the screw 52.

[0033] The salt-eluted water is filtered to the outside through numerous holes on the outer periphery of the screen 51. The outer periphery of the screen 51 gradually narrows from the bottom end to the top end, while the screw 52 has a constant outer diameter, and the gap between the screen 51 and the screw 52 gradually narrows in the pumping direction. Therefore, as the screw 52 rotates, the squeezing force on the desalted sand inside the screen 51 gradually increases, so that the salt-eluted water is efficiently and reliably squeezed out of the desalted sand.

[0034] The salt-eluted water filtered through the screen 51 drops through a water outlet 53 provided at the bottom of the screen 51 and is received as is in a settling tank 61 of the recovery section 60, which will be described below. On the other hand, the desalted sand that has been pumped to the top of the screen 51 is discharged through a solids outlet 54 provided at the top of the screen 51 and is sent as is to a mixing storage tank 70, which will be described below. The bottom of the screen 51 is connected to the boiling outlet 45 of the boiling elution section 40.

[0035] <Regarding the collection unit 60> The recovery unit 60 aggregates residues contained in the salt-eluted water that has fallen from the separation unit 50 and recovers them as sediment. Because the salt-eluted water from the separation unit 50 still contains residues such as shell powder, the salt-eluted water is cooled and then treated to recover the residues. In this embodiment, the recovery unit 60 is, for example, composed of a coagulation and sedimentation device, which adds a coagulant such as a metal salt to the salt-eluted water to solidify and sink the residues in the water.

[0036] The coagulation and sedimentation device, which is the recovery section 60, is equipped with a settling tank 61 that stores salt-eluted water, and the salt-eluted water that falls from the separation section 50 is dispersed evenly from the center to the periphery of the settling tank 61 through a center well (dispersion cylinder) 62 disposed in the center of the settling tank 61. A coagulant such as a metal salt is added to the upper opening of the center well 62 from a coagulant tank 63 as needed by operating a pump.

[0037] In the settling tank 61, the residue solidifies with the coagulant and accumulates at the center of the bottom of the inverted cone of the settling tank 61. The recovery pump 64 operates to supply the resulting precipitate to the mixing storage tank 70, which will be described below, via piping, and the resulting precipitate is effectively utilized together with the desalted sand instead of being discarded. Meanwhile, in the settling tank 61, the upper layer of water, from which the residue has been removed and which contains only salt, is discharged from the top of the settling tank 61 as supernatant water, or it may be reused to add water to the boiling elution unit 40. Note that although the recovery unit 60 has been described as being of a batch type having a single settling tank 61, it may also be configured to be divided into multiple treatment tanks for continuous treatment.

[0038] <About the Mixing Storage Tank 70> The mixing storage tank 70 is configured, for example, in the shape of a tank, and mixes the desalted sand sent from the separation section 50 and the sediment sent from the recovery section 60, temporarily stores a predetermined amount of the mixed sand, and supplies it to the drying section 80, which will be described next. The top of the mixing storage tank 70 is connected to the solids discharge outlet 54 of the separation section 50, and also to the end of the pipe that transfers the sediment from the bottom of the settling tank 61 of the recovery section 60.

[0039] A screw 71 forming a conveyor is rotatably provided on the bottom of the mixing storage tank 70. A discharge section 72 for discharging the mixture of desalted sand and sediment to the outside is provided near the bottom of the peripheral wall of the mixing storage tank 70. The discharge section 72 is connected to the bottom side of the peripheral wall of the drying section 80 described below, and the terminal end of the screw 71 is inserted into the discharge section 72. In the mixing storage tank 70, the amount of the mixture of desalted sand and sediment supplied to the drying section 80 can be adjusted by controlling the rotation of the screw 71.

[0040] <About the drying section 80> The drying section 80 heats the mixture from the mixture storage tank 70 and evaporates the remaining water in the mixture to produce a dried product. In this embodiment, the drying section 80 is configured using a drying device that the applicant has independently developed and calls a cyclone dryer, similar to the boiling and leaching section 40. That is, the drying section 80 has a vertical cylindrical shape and includes a drying tank 81 into which the mixture is introduced and a rotary winding blade 810 attached to a rotary shaft 801 inside the drying tank 81. The drying section 80 has the same basic configuration as the boiling and leaching section 40.

[0041] The drying tank 81 has the same configuration as the boiling tank 41, and is supported on the floor by legs 82. The inner wall of the drying tank 81 serves as a heat transfer surface 83 similar to the heat transfer surface 43, and a jacket 84 is provided to surround the outer periphery of the drying tank 81. The jacket 84 also has an inlet 84a that introduces the heat medium into the interior and an outlet (not shown) that discharges the heat medium to the outside. Other configuration examples of the heating means in the boiling tank 41 are also the same for the drying tank 81. Note that in the drying tank 81, the inlet 84a is located at the top of the jacket 84, but in the boiling tank 41, the inlet 44a is located at the bottom of the jacket 44.

[0042] There are various configurations for supplying the mixture from the separation section 50 into the interior of the drying tank 81 and discharging the dried product to the outside, but specifically, for example, the lower part of the peripheral wall of the drying tank 81 is connected to the delivery section 72 of the mixture storage tank 70, which supplies the mixture to the interior. The supply of the mixture from the delivery section 72 is adjusted by the rotational drive of the screw 71 described above. Meanwhile, a product discharge section 85 for discharging the dried product to the outside is provided on the opposite side of the lower part of the peripheral wall of the drying tank 81 from the connection point of the delivery section 72.

[0043] The product discharge section 85 is formed, for example, in a tubular shape, and a screw 86 is rotatably inserted therein. The downstream side of the product discharge section 85 is connected to a product storage tank 90 (described below) located below it. The discharge of the dried product from the drying tank 81 is regulated by the rotation of the screw 86. The product discharge section 85 differs in specific configuration and location from the boiled product discharge port 45 in the boiling tank 41. Note that in the drying tank 81, the delivery section 72 of the mixing storage tank 70 is connected to the lower part of the peripheral wall, whereas in the boiling tank 41, the delivery section 32 of the mixing storage tank 70 is connected to the upper part of the peripheral wall.

[0044] Similar to boiling tank 41, drying tank 81 also has a rotating shaft 801 disposed therein, with its upper end connected to electric motor 802 and its lower end journaled by bearing 803. Rotating shaft 801 is also provided with rotating blade 810 having the same configuration as rotating blade 410. That is, rotating blade 810 also has a plurality of base blades 811 arranged in the circumferential direction, and each base blade 811 is connected to the tip of arm 812 and has flat surface 811a.

[0045] In the drying section 80, the mixture of desalted sand and sediment supplied into the drying tank 81 is heated by repeatedly rising and falling while being pressed against the heat transfer surface 83 in the form of a thin film by centrifugal force and inertial force due to the rotation of the rotary winding blades 810, as in the boiling and leaching section 40. As a result, the water remaining in the mixture is sufficiently evaporated, and a desalted dried product containing calcium carbonate as the main component is produced. Therefore, the drying section 80 exhibits the original function of a cyclone dryer.

[0046] <Product Storage Tank 90> The product storage tank 90 is configured, for example, in the shape of a tank, and temporarily stores a predetermined amount of the dried material sent from the drying section 80. The upper surface of the product storage tank 90 is connected to the product discharge section 85 of the drying section 80.

[0047] A screw 91 forming a conveyor is rotatably provided on the bottom surface of the product storage tank 90. ​​A delivery section 92 for delivering the dried product to the outside is provided near the bottom surface of the peripheral wall of the product storage tank 90. ​​The dried product discharged from the delivery section 92 may be placed in, for example, a product hopper 93 for shipping.

[0048] <Outline of the desalination and drying process> Next, a desalination and drying process implemented by the desalination and drying system 10 according to this embodiment will be described with reference to the flowchart shown in Figure 2. This desalination and drying process is a method for producing a dried product by removing salt from raw materials, mainly shellfish, and then drying them. In this embodiment, the term "process" includes not only independent processes but also processes that cannot be clearly distinguished from other processes, as long as the process achieves its intended purpose.

[0049] <About the crushing process> In the crushing step, scallop shells, which are the raw material to be processed and prepared in advance, are crushed in two stages by the crushing unit 20 to produce sand-like material (step S101). In the crushing unit 20, the scallop shells are first crushed into coarse particle sizes by the coarse crusher 21 (coarse crushing), and then crushed into fine particle sizes by the fine crusher 22 (fine crushing). The maximum particle size of the sand-like material is preferably in the range of 0.5 mm to 2.5 mm, for example. Such sand-like material has a large surface area, which makes it easier for salt to be eluted in the boiling elution step described below.

[0050] The raw material to be processed in this desalination and drying process is not necessarily limited to scallop shells, but is primarily applicable to shells in general. However, scallop shells are the most readily available shells that become industrial waste in Japan. This promotes the effective use of industrial waste, making it possible to reduce waste disposal costs and environmental impact. The finely crushed sand-like material in the crushing process is transported to the raw material storage tank 30 and temporarily stored up to a predetermined amount. The sand-like material in the raw material storage tank 30 is then appropriately supplied to the boiling and leaching section 40. As mentioned above, water may be added in advance to the sand-like material stored in the raw material storage tank 30.

[0051] <About the boiling elution process> In the boiling and leaching process, water is added to the sandy material supplied from the raw material storage tank 30 by the boiling and leaching unit 40, and the sandy material is boiled by adding water to dissolve the salt contained in the sandy material into the high-temperature boiled water (step S102). That is, according to the boiling and leaching unit 40, the sandy material supplied to the boiling tank 41 has a large contact area with the high-temperature boiled water added with water by the heat transfer surface 43, and the shell structure expands, and the sandy material repeatedly rises and falls while being pressed against the heat transfer surface 43 in a thin film shape by the rotation of the rotating winding blades 410.

[0052] As a result, the sandy material to which water has been added is heated in the boiling tank 41, causing friction and rubbing against each other, until it is thoroughly boiled by the boiling phenomenon. Therefore, the salt contained in the sandy material is dissolved into the high-temperature boiling water and thoroughly desalinated. In the boiling and leaching process, the boiling and leaching unit 40 does not need to dry the sandy material, as is the original function of a cyclone dryer; it is sufficient if it can be desalted by boiling. There are no particular restrictions on the temperature or time for boiling, but a temperature of 100°C or higher for 30 minutes or more is suitable, and these are set appropriately depending on the type and quantity of shells.

[0053] <About the separation process> In the separation step, the separation unit 50 separates the desalted sand, which is obtained by eluting salt from the sand, from the salt-eluted water containing salt (step S103). That is, in the separation unit 50, the mixture of the desalted sand and the salt-eluted water from the boiling elution unit 40 flows into the lower end of the screen 51, and the salt-eluted water is separated from the desalted sand as it is pumped by the rotation of the screw 52.

[0054] As shown in Figure 1, the salt-eluted water filtered through the screen 51 falls through a water outlet 53 provided at the bottom of the screen 51 and is received in a settling tank 61 of a recovery section 60 through a center well 62. On the other hand, the desalted sand that has been pumped up to the top of the screen 51 is discharged through a solids outlet 54 provided at the top of the screen 51 and is received directly in a mixing storage tank 70.

[0055] <About the collection process> In the recovery process, the recovery unit 60 flocculates residues contained in the salt-eluted water and recovers them as sediment (step S104). The salt-eluted water separated from the solids in the separation unit 50 still contains shellfish fine powder as residue, which is also recovered and put to effective use. That is, in the recovery unit 60, the salt-eluted water from the separation unit 50 is stored in the settling tank 61 and cooled, and then a flocculant is added to recover the solidified sediment, which is then sent to the mixing storage tank 70.

[0056] In the mixed storage tank 70, the sediment from the recovery section 60 is stored in a mixed state with the desalted sand from the separation section 50. The mixture of desalted sand and sediment stored in the mixed storage tank 70 is then supplied to the drying section 80. In the settling tank 61, the upper layer of water from which the residue has been removed and which contains only salt is discharged as supernatant water from the top of the settling tank 61 into rivers or sewers if the standard value is met. Alternatively, the supernatant water may be reused for adding water in the boiling and elution section 40.

[0057] <About the drying process> In the drying step, the mixture of desalted sand and precipitate supplied from the mixing storage tank 70 is heated and dried in the drying unit 80, and the remaining water in the mixture is evaporated to produce a powdery dried product (step S105). That is, in the drying unit 80, the mixture supplied to the drying tank 81 is heated by repeatedly rising and falling while being pressed against the heat transfer surface 83 in the form of a thin film by the rotation of the rotary lifting blades 810, as in the case of the boiling and eluting unit 40.

[0058] As a result, the water remaining in the mixture is sufficiently evaporated in the drying tank 81, and a desalted dried product containing calcium carbonate as the main component is produced. Therefore, the drying section 80 functions as a cyclone dryer. There are no particular restrictions on the temperature and time for drying, and these can be set appropriately depending on, for example, the type and quantity of shells.

[0059] The dried product produced in the drying section 80 is sent to and stored in a product storage tank 90, and then transferred to a product hopper 93 for shipment. This completes the series of steps in this desalination drying process. The specific operations of this desalination drying system 10 and the entire process are controlled by a control device equipped in this desalination drying system 10, i.e., a computer equipped with a CPU, RAM, ROM, I / O, etc.

[0060] <Uses of dried products> The dried product is made from shells from which the salt has been removed, and its main component is calcium carbonate. Because this dried product is inorganic, it will be called "shell sand." There are no particular restrictions on the uses of shell sand, and it can be used for a wide range of purposes in various fields.

[0061] Shell sand can be used, for example, as a raw material for cement or as an aggregate for concrete. Generally, when used in cement or concrete, as long as the salt content in the raw material is 160 ppm or less, there is no risk of salt damage, and it can be used in a wide range of cement or concrete applications.

[0062] In particular, when scallop shells are used as a raw material, scallops grow by absorbing carbon dioxide from seawater, and are known to have the effect of fixing carbon dioxide in seawater and the atmosphere. Therefore, using scallop shells as a raw material for cement or aggregate for concrete makes it possible to fix carbon dioxide for a long period of time, contributing to the prevention of global warming, one of the SDGs. Furthermore, it also reduces the amount of sand quarried, which is the original raw material for cement.

[0063] Another use of shell sand is as road paving material. Furthermore, shell sand can be mixed into plant fertilizer or animal feed. However, if the crushed shells are used as they are without removing the salt, it can cause stunting of plant and animal growth.

[0064] <Configuration and effects of the present invention> Although various embodiments of the present invention have been described above, the present invention is not limited to the above-described various embodiments. The present invention derived from the above-described various embodiments will be described below.

[0065] First, the present invention provides a desalination and drying system 10 for removing salt from a raw material to be processed, mainly consisting of shells, and then drying the raw material to produce a dried product, a boiling and elution unit 40 in which water is added to sand-like material obtained by crushing the raw material to be processed into sand and boiling the material to elute salt contained in the sand into high-temperature boiling water; a separation unit 50 for separating desalted sand obtained by eluting salt from the sand and salt-eluted water containing salt; a recovery section 60 for flocculating residues contained in the salt-eluted water and recovering them as precipitates; and a drying section 80 for heating the mixture of the desalted sand and the precipitate to evaporate the water remaining in the mixture to produce the dried product.

[0066] This desalination and drying system 10 utilizes the property that salt dissolves easily in high-temperature water to easily and efficiently produce high-quality, versatile dried products from raw materials, primarily shells, by removing salt. This makes it possible to further promote the effective use of shells, which have previously been industrial waste, and reduces disposal costs and environmental impact. The raw materials to be processed are not necessarily limited to shells, and may also contain shellfish meat or algae or other attachments.

[0067] In addition, the present invention is characterized in that the raw material to be treated is scallop shells. This is because scallops are the most common type of shell that becomes industrial waste in Japan's fishing industry, and this will encourage the effective use of industrial waste, reducing waste disposal costs and environmental impact.

[0068] The present invention also includes a crushing unit 20 for crushing the raw material to be processed in two stages to produce the sand-like material, The crushing section 20 is characterized by comprising a coarse crusher 21 which first crushes the raw material to be processed into coarsely crushed material of a coarse particle size, and then a fine crusher 22 which crushes the coarsely crushed material into finer particle sizes to produce the sand-like material.

[0069] With this crushing unit 20, even if the raw materials to be processed, such as scallop shells, are of irregular size and shape, they can be crushed in two stages to reliably produce sand-like material of uniform fine particle size. Therefore, the surface area of ​​the raw materials to be processed is increased, and the contact area with heated water by boiling with water is also increased, making desalination even easier.

[0070] In the present invention, the boiling and eluting section 40 comprises a boiling tank 41 having a vertical cylindrical shape into which the sand-like material and water are introduced, and a rotary whetstone 410 provided on a rotary shaft 401 extending along a substantially vertical center line within the boiling tank 41, The inner wall of the boiling tank 41 forms a heat transfer surface 43 that is heated by a heating means provided along the outer periphery of the boiling tank 41. As the rotating winding blades 410 are driven to rotate, the sand and water in the boiling tank 41 are repeatedly pushed up and down in a thin film against the heat transfer surface 43 by centrifugal force and inertial force, causing the salt contained in the sand to dissolve into the high-temperature boiling water.

[0071] In this boiling and eluting section 40, the sand-like material supplied to the boiling tank 41 is repeatedly raised and dropped while being agitated by the rotation of the rotating winding blades 410 and pressed against the heat transfer surface 43 in the form of a thin film. As a result, the sand-like material to which water has been added is heated and becomes thoroughly cooked by the boiling phenomenon. Therefore, the salt contained in the sand-like material is dissolved into the high-temperature boiling water and is thoroughly desalted. Note that in the boiling and eluting section 40, it is not necessary to dry the sand-like material to which water has been added; it is sufficient if it can be desalted by boiling.

[0072] In the present invention, the separation unit 50 comprises a substantially cylindrical screen 51 disposed at an incline, and a screw 52 inserted into the screen 51 for lifting the desalted sand against the incline, The outer periphery of the screen 51 gradually decreases in diameter from the lower end to the upper end with respect to the screw 52, ​​which has a constant outer diameter, and the gap between the screen 51 and the screw 52 narrows in the direction of pumping. The desalted water filtered by the screen 51 is discharged from the lower end side of the screen 51, and the desalted sand-like material pumped by the screw 52 is discharged from the upper end side of the screen 51.

[0073] According to such a separation section 50, with a simple configuration consisting of the screen 51 and the screw 52, ​​it is possible to efficiently separate salt-eluted water containing salt from the desalted sand obtained by desalting the sand.

[0074] In the present invention, the recovery unit 60 includes a settling tank 61 for storing the salt-eluted water, and a flocculant is added to the settling tank 61. The sediment formed by the residue solidifying with a flocculant in the settling tank 61 is discharged from the bottom of the settling tank 61, and the supernatant water from which the residue has been removed and which contains only salt is discharged from the top of the settling tank 61.

[0075] The recovery unit 60 can reliably desalinate even residues that are difficult to remove salt from, allowing the entire residue to be used as a raw material for dried products without waste. The upper layer of water in the settling tank 61, from which the residue has been removed and which contains only salt, is discharged as supernatant water if it satisfies the standard value. Alternatively, the supernatant water may be reused for adding water in the boiling and eluting unit 40.

[0076] In the present invention, the drying section 80 includes a vertical cylindrical drying tank 81 into which the mixture of the desalted sand and the precipitate is introduced, and a rotary winding blade 810 provided on a rotary shaft 801 extending along a substantially vertical center line within the drying tank 81, The inner wall of the drying tank 81 forms a heat transfer surface 83 that is heated by a heating means provided along the outer periphery of the drying tank 81, As the rotary winding blade 810 is driven to rotate, the mixture in the drying tank 81 is repeatedly raised and dropped while being pressed against the heat transfer surface 83 in the form of a thin film by centrifugal force and inertial force, and the water remaining in the mixture is evaporated to produce the dried product.

[0077] In this drying section 80, the mixture of desalted sand and sediment fed into the drying tank 81 is heated by repeatedly rising and falling while being pressed into a thin film against the heat transfer surface 83 by centrifugal force and inertial force due to the rotation of the rotary lifting blade 810, just as in the boiling and leaching section 40. As a result, the water remaining in the mixture is sufficiently evaporated, and a desalted dried product is produced.

[0078] Therefore, the drying section 80 can perform the original function of a cyclone dryer. Moreover, since the drying section 80 has basically the same configuration as the boiling and eluting section 40, it can be easily manufactured using common parts.

[0079] Furthermore, the present invention provides a desalination and drying process for producing a dried product by removing salt from a raw material to be processed, mainly shellfish, and then drying the raw material, comprising: a crushing step of crushing the raw material to be processed into sand-like material; a boiling and leaching step in which water is added to the sand and boiled to dissolve salt contained in the sand into high-temperature boiled water; a separation step of separating the sand into desalted sand obtained by eluting salt from the sand and salt-eluted water containing salt; a recovery step of flocculating residues contained in the salt-eluted water and recovering them as precipitates; and a drying step in which the desalted sand and the precipitate are mixed and heated to evaporate the remaining water to produce a powdery dried product.

[0080] This desalination and drying process can easily and efficiently produce a high-quality, versatile dried product from raw materials, primarily shells, with salt removed. This will further promote the effective use of industrial waste, primarily shells, and reduce disposal costs and environmental impact.

[0081] Although the embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these embodiments, and modifications and additions that do not deviate from the gist of the present invention are also included in the present invention. For example, in addition to scallop shells, the raw material to be treated may also be the shells of oysters, clams, short-necked clams, turban shells, abalone, etc. These may be used alone or in combination of two or more types. [Industrial Applicability]

[0082] The desalination and drying system and process of the present invention can easily and efficiently produce a high-quality, versatile dried product from processed raw materials, mainly shells, with salt removed, and the dried product can be widely used in fields such as cement raw materials. [Explanation of symbols]

[0083] 10...Desalination and drying system 20...Crushing section 21...Crusher 22...pulverizer 30...Raw material storage tank 40…Boiling elution part 50…Separation part 60...Collection section 70...Mixing storage tank 80...Drying section 90...Product storage tank 93...Product hopper

Claims

1. A desalination and drying system for removing salt from a raw material to be processed, mainly consisting of shells, and then drying the raw material to produce a dried product, comprising: a boiling and elution unit that adds water to sand-like material obtained by crushing the raw material to be processed into sand and boils the material to elute salts contained in the sand into high-temperature boiling water; a separation unit that separates desalted sand obtained by eluting salt from the sand and salt-eluted water containing salt; a recovery unit that aggregates residues contained in the salt-eluted water and recovers them as precipitates; a drying section that heats the mixture of the desalted sand and the precipitate and evaporates the water remaining in the mixture to produce the dried product.

2. 2. The desalination and drying system according to claim 1, wherein the raw material to be treated is scallop shells.

3. a crushing unit for crushing the raw material to be processed in two stages to produce the sand-like material; The desalination and drying system according to claim 1, characterized in that the crushing section comprises a coarse crusher that first crushes the raw material to be processed into coarsely crushed material, and then a fine crusher that crushes the coarsely crushed material into finer particle sizes to produce the sand-like material.

4. the boiling and elution unit comprises a vertical cylindrical boiling tank into which the sand and water are introduced, and a rotary pick-up blade provided on a rotary shaft extending along a substantially vertical center line within the boiling tank; the inner wall of the boiling tank forms a heat transfer surface that is heated by a heating means provided along the outer periphery of the boiling tank; The desalination and drying system of claim 1, characterized in that, as the rotating winding blades are driven to rotate, the sand-like material and water in the boiling tank are repeatedly pushed up and down as a thin film against the heat transfer surface by centrifugal force and inertial force, causing the salt contained in the sand-like material to dissolve into the high-temperature boiling water.

5. The separation unit comprises a substantially cylindrical screen disposed at an incline, and a screw inserted into the screen for lifting the desalted sand against the incline, The outer periphery of the screen gradually narrows from the lower end to the upper end with respect to the screw, which has a constant outer diameter, and the gap between the screen and the screw narrows in the lifting direction, 2. The desalination and drying system of claim 1, wherein the salt-eluted water filtered by the screen is discharged from the lower end side of the screen, and the desalted sand-like material pumped by the screw is discharged from the upper end side of the screen.

6. The recovery unit includes a settling tank that stores the salt-eluted water, and a flocculant is added to the settling tank.

2. The desalination and drying system according to claim 1, wherein the sediment formed by the residue solidifying with the coagulant in the settling tank is discharged from the bottom of the settling tank, and the supernatant water from which the residue has been removed and which contains only salt is discharged from the top of the settling tank.

7. the drying section includes a vertical cylindrical drying tank into which the mixture of the desalted sand and the precipitate is introduced, and a rotary pick-up blade provided on a rotary shaft extending along a substantially vertical center line within the drying tank; the inner wall of the drying tank forms a heat transfer surface that is heated by a heating means provided along the outer periphery of the drying tank; 7. The desalination and drying system according to claim 1, wherein the rotation of the rotary winding blades causes the mixture in the drying tank to repeatedly rise and fall while being pressed against the heat transfer surface in the form of a thin film by centrifugal force and inertial force, thereby evaporating water remaining in the mixture to produce the dried product.

8. A desalination and drying process for producing a dried product by removing salt from a raw material to be processed, mainly shellfish, and then drying the raw material, a crushing step of crushing the raw material to be processed into sand-like material; a boiling and leaching step in which water is added to the sand and boiled to dissolve salt contained in the sand into high-temperature boiled water; a separation step of separating the sand into desalted sand obtained by eluting salt from the sand and salt-eluted water containing salt; a recovery step of flocculating residues contained in the salt-eluted water and recovering them as precipitates; a drying step in which the desalted sand and the precipitate are mixed and heated to evaporate the remaining water to produce a powdery dried product.

Images