Processing method of particle and processor
Patent Information
- Application Number
- JP2022132207
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2022-08-23
- Publication Date
- 2025-07-15
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
[Technical field]
[0001] The present invention relates to a particle processing method and processing apparatus capable of stably granulating particles that are uniformly dried to a desired level and have a desired particle size. [Background technology]
[0002] When producing granular products (e.g., chemical products, medicines, and foods), it is necessary to process solid substances into particles of a desired particle size. As a processing method suitable for mass production of granular products, for example, a method is known in which seed particles (small particles made of the above-mentioned solid substances) are enlarged using a granulation device of a fluidized bed type or a fluidized bed / spouted bed type to obtain particles of a desired particle size. Specifically, a fluidized bed (or a fluidized bed and a spouted bed) of seed particles is formed by supplying gas to the seed particles from below, and a solution containing a coating substance (the above-mentioned solid substance) is sprayed onto the seed particles in this layer to attach the solution in droplets, and the solution is dried at the same time. As a result, the surfaces of the seed particles are coated with the coating substance in the solution, and particles larger in size than the seed particles are obtained.
[0003] Patent Document 1 describes a method for processing particles using a granulator of the fluidized bed / spouted bed type. In Fig. 1, a fluidized bed gas (gas for forming a fluidized bed) is uniformly supplied from a bottom bed 6, which is a porous plate, to form a space 7 for a fluidized bed of processed particles (fluidized bed), and at the same time, gas (gas for forming a spouted bed) is ejected from a supply pipe 12, and a solution containing a coating material is sprayed from a nozzle 13 to form an ascending / falling space 8 (spouted bed) for processed particles. Then, the droplet-like coating material sprayed from this nozzle 13 adheres to the surface of the processed particles (seed particles), resulting in enlarged particles.
[0004] Particles obtained by a fluidized bed or fluidized / spouted bed granulator usually have a wide particle size distribution. Therefore, it is necessary to classify these particles into product-sized particles (particles having the desired particle size), large particles exceeding the product size, and small particles below the product size. The product-sized particles are then recovered. Meanwhile, the large particles are crushed to reduce their size, and these are fed to the granulator as seed particles for recycling. The small particles are fed directly to the granulator as seed particles for recycling. [Prior art documents] [Patent documents]
[0005] [Patent Document 1] Special Publication No. 4-63729 Summary of the Invention [Problem to be solved by the invention]
[0006] In the above-described method, it is desirable to maintain the temperature of the seed particles at an appropriate temperature that can promote drying. Therefore, in a conventional general method, for example, a gas for forming a fluidized bed (or a gas for forming a fluidized bed and a gas for forming a spouted bed) is heated to maintain an atmosphere at a temperature higher than room temperature in a region where granulation by coating is performed by using this gas.
[0007] On the other hand, the particles to be recycled as seed particles after passing through each process such as the classification process lose heat in each process and therefore the temperature of the seed particles supplied to the granulator is usually lower than the temperature inside the granulator.
[0008] Furthermore, the seed particles to be supplied to the granulator may be exposed to the outside air before being supplied, and may absorb moisture, resulting in a high moisture content. Also, the temperature may fluctuate due to seasonal temperature differences and daytime and nighttime temperature differences.
[0009] As explained above, the temperature and moisture content of the seed particles supplied to the granulator vary due to various reasons. The present inventors have noticed that when seed particles with a low temperature or high moisture content are supplied to the granulator, the temperature inside the granulator (particularly near the seed particle supply port) drops partially, causing insufficient or uneven drying, resulting in a decrease in product quality, and have thought that it is necessary to improve this.
[0010] That is, an object of the present invention is to provide a particle processing method and processing apparatus capable of stably granulating particles that are uniformly dried to a desired level and have a desired particle size. [Means for solving the problem]
[0011] As a result of intensive research into achieving the above-mentioned object, the inventors have discovered that it is extremely effective to add a seed particle adjustment step utilizing a preheating gas and a fluidized bed prior to the granulation step and to preheat the seed particles in this seed particle adjustment step, thereby completing the present invention.
[0012] The present invention provides a method for producing a powdery raw material by a method comprising the steps of: (a) forming a fluidized bed of seed particles and preheating the seed particles in the fluidized bed by supplying a preheating gas to the seed particles from below; A granulation step (gr) of granulating the seed particles by coating the surface of the seed particles heated in the seed particle adjustment step (sc) with a coating material in a high-temperature atmosphere. A method for processing particles having the above structure.
[0013] The present invention also provides a seed particle conditioning device (SC) for forming a fluidized bed of seed particles and preheating the seed particles in the fluidized bed by supplying a preheating gas to the seed particles from below, A granulation device (GR) for granulating the seed particles by coating the surface of the seed particles heated by the seed particle conditioning device (SC) with a coating material in a high-temperature atmosphere. The particle processing device has a structure as follows.
[0014] The present invention also provides a seed particle conditioning zone (SCZ) for forming a fluidized bed of seed particles and preheating the seed particles in the fluidized bed by supplying a preheating gas to the seed particles from below, A granulation zone (GRZ) in which the surface of the seed particles heated in the seed particle conditioning zone (SCZ) is coated with a coating material in a high-temperature atmosphere to granulate the seed particles. The present invention relates to a particle processing device having a seed particle adjusting and granulating device (SC / GR) including:
[0015] The present invention also provides a method for improving an existing particle processing apparatus having a granulator (GR) for granulating seed particles by coating the surfaces of the seed particles with a coating material in a high-temperature atmosphere, comprising the steps of: A seed particle conditioning device (SC) that forms a fluidized bed of seed particles by supplying a preheating gas to the seed particles from below and preheats the seed particles in the fluidized bed is added to the existing particle processing device, and in the granulation device (GR), the seed particles that have been heated in the seed particle conditioning device (SC) are granulated by coating them with a coating material in a high-temperature atmosphere, or The granulation device (GR) is replaced with a seed particle conditioning and granulation device (SC / GR) including a seed particle conditioning zone (SCZ) for forming a fluidized bed of seed particles and preheating the seed particles in the fluidized bed by supplying a preheating gas to the seed particles from below, and a granulation zone (GRZ) for granulating the surfaces of the seed particles heated in the seed particle conditioning zone (SCZ) by coating them with a coating substance in a high-temperature atmosphere, and the seed particles heated in the seed particle conditioning zone (SCZ) are granulated in the granulation zone (GRZ) by coating them with a coating substance in a high-temperature atmosphere. This is a method for improving an existing particle processing device, characterized by the above. Effect of the Invention
[0016] The particle processing method of the present invention is characterized by having a seed particle adjusting step (sc). In this seed particle adjusting step (sc), the seed particles are preheated by a preheating gas. Therefore, the temperature of the seed particles becomes high. By using these seed particles for granulation, it is possible to suppress a decrease in the temperature uniformity and drying uniformity in the granulation device (GR), particularly near the seed particle supply port.
[0017] In addition, in this seed particle adjustment step (sc), a fluidized bed of seed particles is formed by supplying a preheating gas. As a result, the seed particles in the fluidized bed are heated by this preheating gas. This type of heating method using a fluidized bed is superior to other heating methods in terms of the uniformity of the temperature of the seed particles. Therefore, it is possible to more effectively suppress the deterioration of the temperature uniformity and the drying uniformity in the granulator (GR).
[0018] As described above, the particle processing method of the present invention includes the seed particle adjustment step (sc), which can suppress deterioration of the temperature uniformity and drying uniformity in the granulator (GR). Therefore, according to the present invention, particles that are uniformly dried to a desired level and have a desired particle size can be stably granulated. [Brief description of the drawings]
[0019] [Figure 1] FIG. 1 is a process flow diagram illustrating one embodiment of the method and apparatus of the present invention. [Diagram 2] FIG. 2 is a process flow diagram illustrating another embodiment of the method and apparatus of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] <Granulation process (gr)> In the present invention, the granulation step (gr) is a step of granulating the surfaces of the seed particles heated in the seed particle adjustment step (sc) by coating them with a coating material in a high-temperature atmosphere. The granulation device (GR) is a device for granulating the surfaces of the seed particles heated in the seed particle adjustment device (SC) by coating them with a coating material in a high-temperature atmosphere.
[0021] The granulation method in the granulation step (gr) is not particularly limited, and any method can be used as long as the surface of the seed particles is coated with a coating substance in a high-temperature atmosphere. For example, a method can be used in which the surface of the seed particles is coated with the coating substance by spraying a coating solution containing the coating substance onto the seed particles. According to this method, droplets of the solution are attached to the surface of the seed particles and dried, and particles larger than the seed particles can be granulated.
[0022] As such a granulation method, from the viewpoint of uniformity of the coating state and uniformity of drying, a granulation method by a fluidized bed method in which a fluidized bed is formed and granulation is performed, and a granulation method by a fluidized bed / spouted bed method in which a fluidized bed and a spouted bed are formed and granulation is performed, and in particular, a granulation method by a fluidized bed / spouted bed method is more preferable. However, the granulation method is not limited to these, and other methods can also be used. Examples of other methods include a granulation method by a rolling granulation method or an agitation granulation method.
[0023] In the granulation step (gr), when granulation is performed by the fluidized bed method or the fluidized bed / spouted bed method, a fluidized bed of seed particles is formed by supplying heated fluidizing gas to the seed particles from below. The term "fluidized bed" refers to a layered space containing floating and flowing seed particles. The term "fluidizing gas" refers to gas that is supplied almost uniformly to the seed particles from below through a member such as a perforated plate in order to form such a fluidized bed. Furthermore, the term "seed particles" in the granulation step (gr) refers not only to seed particles before granulation (seed particles that are not coated with anything at the time of supply), but also to seed particles in the middle of granulation (seed particles that are coated to some extent with a coating material).
[0024] In the case of granulation by the fluidized bed method, the surface of the seed particles is coated with the coating substance by spraying a solution containing the coating substance onto the seed particles in the fluidized bed. The solution containing the coating substance may be sprayed from a position different from the supply position of the fluidizing gas, or may be sprayed together with the fluidizing gas. In particular, it is preferable to spray the solution together with the fluidizing gas.
[0025] On the other hand, when granulation is performed by the fluidized bed / spouted bed method, not only a fluidized bed but also a spouted bed is formed by spraying heated spouted gas from below onto the seed particles. The term "spouted bed" refers to a protruding space that contains the seed particles that are suspended and flow up and down. The term "spouted gas" refers to gas that is partially sprayed from below onto the seed particles to form such a spouted bed. When granulation is performed by the fluidized bed / spouted bed method, it is preferable to spray a solution containing a coating material together with the spouted gas.
[0026] In the granulation step (gr), the coating state and the drying state can be adjusted by performing granulation in a high-temperature atmosphere. "Performing granulation in a high-temperature atmosphere" means performing granulation in a gas with a temperature higher than room temperature (atmospheric temperature). For example, in the embodiment shown in FIG. 1, the temperature of the gas in at least the region in which granulation is performed in the granulation device (GR) is higher than room temperature. The temperature of the particles also becomes approximately the same as that of this atmosphere. The gas forming this atmosphere is typically air. However, the present invention is not limited to this, and gases other than air, such as nitrogen, can also be used.
[0027] The gas forming the above atmosphere in the granulation step (gr) is, for example, a gas containing the gas supplied to form a fluidized bed when granulation is performed by a fluidized bed method, and a gas containing the gas supplied to form a fluidized bed and the gas supplied to form a spouted bed when granulation is performed by a fluidized bed / spouted bed method. For example, the temperature of the gas in the granulation region can be adjusted by appropriately heating the gas supplied for such a purpose before supplying it. The specific temperature of the atmosphere in which granulation is performed is not particularly limited, and may be appropriately determined depending on the type of the desired granular product. However, it is preferably 80°C to 140°C. For example, when particles such as urea particles are produced, it is more preferably 95°C to 120°C, and particularly preferably 110°C to 120°C. Furthermore, for example, when particles such as urea particles are produced, the temperature of the solution containing the coating material is preferably 125°C to 145°C.
[0028] The supply or ejection pressure, supply or ejection velocity, and supply or ejection flow rate of the fluidizing gas and the jetting gas may be appropriately adjusted so that a fluidized bed and a spouted bed can be appropriately formed depending on various conditions such as the particle size, weight, and amount of the seed particles and the particles after granulation used. The spray pressure, spray velocity, and spray flow rate of the solution containing the coating material may also be appropriately adjusted depending on the above-mentioned various conditions of the seed particles and the particles after granulation used.
[0029] In the solution containing the coating material used in the granulation step (gr), the concentration of the coating material may be appropriately adjusted so as to obtain a good coating state. In addition, before using this solution in the granulation step (gr), a part of the liquid in the solution may be evaporated in an evaporation step (ev) to increase the concentration of the coating material. The concentration of the coating material in the solution used in the granulation step (gr) may be appropriately adjusted depending on various conditions such as the type of material and particle size of the seed particles and the particles after granulation to be used. For example, when producing particles such as urea particles, the concentration of the coating material in the solution is preferably 94% by mass to 98.5% by mass. The solvent is preferably water. However, the present invention is not limited thereto.
[0030] The average particle size of the particles obtained in the granulation step (gr) is preferably 0.4 mm to 10 mm, more preferably 1 mm to 6 mm. This average particle size is a value measured by a sieving test method in accordance with JIS Z 8815. For example, particles having such an average particle size can be classified to obtain particles of the product size (particles having a desired particle size).
[0031] The moisture content of the particles obtained in the granulation step (gr) is preferably 0.5% by mass or less, more preferably 0.2% by mass or less. This moisture content is a value measured by Karl Fischer titration. Particles with such a low moisture content have excellent handleability.
[0032] The particles obtained in the granulation step (gr) are preferably classified in a particle classification step (pc) to recover particles of the product size (particles having a desired particle size). The particle classification step (pc) will be described in detail later.
[0033] The gas discharged from the granulation process (GR) usually contains a small amount of dust. The gas containing the dust discharged from the granulation process (GR) is preferably washed, for example, in a gas washing process (GW) to remove the dust, and the washed gas is discharged, while the removed dust is preferably returned to the solution containing the coating material (for example, the solution in the solution tank) for recycling.
[0034] FIG. 1 is a process flow diagram illustrating one embodiment of the method and apparatus of the present invention.
[0035] In FIG. 1, seed particles heated in a seed particle conditioning device (SC) are supplied to a fluidized bed / spouted bed type granulator (GR) via line 1. A solution (containing a coating material) from a solution tank (ST) is supplied to the granulator (GR) via line 2, an evaporation unit (EV), and line 3. In the evaporation unit (EV), a part of the liquid in the solution is evaporated to increase the concentration of the coating material. A jetted gas is supplied to the granulator (GR) via line 4, and a fluidized gas is supplied to the granulator (GR) via line 5, thereby forming a fluidized bed and a spouted bed. In the granulator (GR), the solution containing the coating material is sprayed together with the jetted gas to coat the surfaces of the seed particles with the coating material and granulate them. The granulated particles are supplied to a particle classifier (PC) via line 6.
[0036] In Fig. 1, the dust-containing gas discharged from the granulator (GR) is supplied via line 7 to a gas cleaning unit (GW) equipped with a device such as a scrubber. In this gas cleaning unit (GW), the gas is cleaned to remove the dust, and the cleaned gas is exhausted via line 8. The removed dust is dissolved in a solvent to form a solution, which is supplied via line 9 to a solution tank (ST) for recycling.
[0037] <Particle classification process (PC) and crushing process (CR)> The method of the present invention preferably includes a particle classification step (pc) for classifying the particles granulated in the granulation step (gr), and recovers the product size particles (particles having the desired particle size) obtained by this classification. It is also preferable to recycle the particles smaller than the product size obtained by this classification as seed particles. Furthermore, the method of the present invention preferably includes a crushing step (cr) for crushing large particles exceeding the product size obtained by classification in the particle classification step (pc), and recycle the particles reduced in size by this crushing as seed particles.
[0038] The apparatus of the present invention preferably has a particle classifier (PC) that classifies the particles granulated in the granulator (GR), and collects the particles of the product size obtained by this classification. It is also preferable to recycle the particles smaller than the product size obtained by this classification as seed particles. Furthermore, the apparatus of the present invention preferably has a crusher (CR) that crushes large particles exceeding the product size obtained by classification in the particle classifier (PC), and it is also preferable to recycle the particles reduced in size by this crushing as seed particles.
[0039] In the above descriptions, "recycle as seed particles" specifically means using as seed particles in seed particle preparation or granulation.
[0040] As a classification method in the particle classification step (pc), for example, there is a method using a screen or a sieve to classify the particles granulated in the granulation step (gr) into particles of the product size, large particles exceeding the product size, and small particles less than the product size. However, the present invention is not limited to this.
[0041] In FIG. 1, the particles granulated in the granulator (GR) are supplied to the particle classifier (PC) via line 6. Two screens (S1) and (S2) are provided inside the particle classifier (PC). First, large particles exceeding the product size do not pass through the screen (S1), while the other particles do. Next, particles of the product size do not pass through the screen (S2), while small particles smaller than the product size pass through. Then, the particles exceeding the product size are supplied to the crusher (CR) via line 10. The particles of the product size are collected via line 11. The particles smaller than the product size are supplied to the seed particle conditioning device (SC) via lines 12 and 14. In addition, the particles crushed to a desired particle size in the crusher (CR) are supplied to the seed particle conditioning device (SC) via lines 13 and 14.
[0042] <Seed particle adjustment process (sc)> In the present invention, the seed particle adjusting step (sc) is a step of forming a fluidized bed of the seed particles and preheating the seed particles in the fluidized bed by supplying a preheating gas to the seed particles from below, and the seed particle adjusting device (SC) is a device that forms a fluidized bed of the seed particles and preheats the seed particles in the fluidized bed by supplying a preheating gas to the seed particles from below.
[0043] As the seed particles to be preheated in the seed particle adjustment step (sc), for example, particles smaller than the product size obtained by classification in the particle classification step (pc) described above, and particles obtained by crushing particles larger than the product size obtained by classification in the particle classification step (pc) described above in the crushing step (cr) can be used. However, the present invention is not limited to these. Particles that have not been subjected to the particle classification step (pc), for example, seed particles prepared in advance such as the nuclei supplied to the granulator in JP-A-11-137988, can also be used.
[0044] The average particle size of the seed particles preheated in the seed particle adjusting step (sc) is preferably 0.4 mm to 3 mm, more preferably 1 mm to 2 mm. This average particle size is a value measured by the method described above.
[0045] In the seed particle adjusting step (sc), a fluidized bed of the seed particles is formed by supplying a preheating gas to the seed particles from below. That is, the preheating gas also functions as a fluidizing gas. This preheating gas is typically air. However, the present invention is not limited to this, and gases other than air, such as nitrogen, can also be used.
[0046] The temperature of the preheating gas in the seed particle adjusting step (sc) is preferably 80° C. to 140° C., more preferably 90° C. to 120° C. This preheating gas is a preheating means for suppressing deterioration of the temperature uniformity in the granulation apparatus (GR) (particularly in the vicinity of the seed particle supply port) and the drying uniformity. Therefore, the temperature of the preheating gas is preferably the same as or close to the temperature of the atmosphere in the granulation step (gr) described above.
[0047] The supply pressure, supply speed and supply flow rate of the preheating gas in the seed particle adjustment step (sc) may be appropriately adjusted so as to form a suitable fluidized bed depending on various conditions such as the particle size, weight and amount of the seed particles used.
[0048] As explained above, in the present invention, the seed particles are preheated in the seed particle adjusting step (sc) before being used in the granulation step (gr), so that the decrease in temperature uniformity and drying uniformity in the granulation equipment (GR) can be suppressed. Furthermore, from the viewpoints of ease of continuous processing and temperature stability, it is preferable that the seed particles heated in the seed particle adjusting step (sc) are supplied to the granulation step (gr) by a method in which the equipment is directly connected and the particles are sent by gravity flow.
[0049] In FIG. 1, crushed particles from the crusher (CR) are supplied to a seed particle conditioning device (SC) via lines 13 and 14, and particles smaller than the product size from the particle classifier (PC) are supplied to the seed particle conditioning device (SC) via lines 12 and 14 to be used as seed particles.
[0050] In Fig. 1, gas is supplied to a heater (H) via line 15, and the temperature of the gas is increased by heat from steam flowing in an internal pipe 18 of the heater (H). The gas heated by the heater (H) is then supplied as preheating gas to a seed particle conditioning device (SC) via line 16. By supplying this preheating gas to the seed particles from below, a fluidized bed of the seed particles is formed and the seed particles in the fluidized bed are preheated. The preheated seed particles are supplied to a granulation device (GR) via line 1.
[0051] In Fig. 1, gas containing dust is discharged from the top of the seed particle conditioning device (SC) and supplied to a gas cleaning device (GW) equipped with a device such as a scrubber via line 17. As explained above, in this gas cleaning device (GW), the gas is cleaned to remove dust, and the cleaned gas is exhausted via line 8. The removed dust is dissolved in a solvent to become a solution, which is supplied to a solution tank (ST) via line 9 for recycling.
[0052] In the above description, the seed particle conditioning device (SC) and the granulation device (GR) are separate devices as shown in Fig. 1. However, the present invention is not limited to this. For example, as shown in Fig. 2, a single device including a seed particle conditioning zone (SCZ) and a granulation zone (GRZ), i.e., a seed particle conditioning and granulation device (SC / GR) may be used.
[0053] In Fig. 2, in the seed particle conditioning and granulation device (SC / GR), a seed particle conditioning zone (SCZ) and a granulation zone (GRZ) separated by a partition wall 19 respectively perform the same functions as the seed particle conditioning device (SC) and the granulation device (GR) described above. Particles preheated in the seed particle conditioning zone (SCZ) are supplied to the granulation zone (GRZ) by falling due to gravity flow. Note that in Fig. 2, for ease of comparison with Fig. 1, both zones are shown side by side, but when particles are supplied to the granulation zone (GRZ) by falling due to gravity flow, it is preferable that the seed particle conditioning zone (SCZ) in the seed particle conditioning and granulation device (SC / GR) is located above the granulation zone (GRZ).
[0054] <Method of improving existing particle processing equipment> The processing apparatus of the present invention may be realized by improving an existing particle processing apparatus.
[0055] For example, the particle processing apparatus of the present invention (see FIG. 1) can be realized by improving an existing particle processing apparatus having a granulation apparatus (GR) by adding a seed particle conditioning apparatus (SC). In this case, in the granulation apparatus (GR), the seed particles after heating in the seed particle conditioning apparatus (SC) are granulated by coating them with a coating material in a high-temperature atmosphere. Also, for example, the particle processing apparatus of the present invention (see FIG. 2) can be realized by improving an existing particle processing apparatus by replacing the granulation apparatus (GR) with a seed particle conditioning and granulation apparatus (SC / GR). In this case, in the granulation zone (GRZ), the seed particles after heating in the seed particle conditioning zone (SCZ) are granulated by coating them with a coating material in a high-temperature atmosphere.
[0056] <Granular products> The particles obtained by the present invention are useful as various granular products, such as chemical products, pharmaceuticals, and foods. In particular, it is preferable to apply the present invention to the production of granular products in which granulation using seed particles is carried out industrially. A preferred example of such a granular product is urea particles. However, the present invention is not limited thereto. For example, the present invention can be applied to the production of granular products other than urea particles, such as ammonium nitrate particles and ammonium sulfate particles.
[0057] When urea particles are obtained by the present invention, the seed particles are urea particles, and the solution containing a coating substance is an aqueous urea solution. The average particle size of the urea particles as a granular product is preferably 1 mm to 5 mm, more preferably 2 mm to 4 mm. The moisture content of the urea particles is preferably 0.5 mass % or less, more preferably 0.2 mass % or less. The average particle size and moisture content are values measured by the method described above. Urea particles having such an average particle size and moisture content are useful for applications such as fertilizer.
[0058] In the present invention, it is preferable that the seed particles and the coating material are made of the same material, as in the urea particles described above. However, the present invention is not limited to this. Depending on the type of the desired granular product, different materials may be used for the seed particles and the coating material. [Industrial Applicability]
[0059] INDUSTRIAL APPLICABILITY The present invention is useful as a particle processing method and processing apparatus capable of stably granulating particles that are uniformly dried to a desired level and have a desired particle size. [Explanation of symbols]
[0060] SC seed particle control device GR granulation equipment ST Solution Tank EV Evaporation Unit GW Gas Cleaning Equipment PC particle classifier S1, S2 Screen CR Crushing Equipment H heater 1 line (seed particle) 2 Line (Solution) 3 Line (Solution) 4 Line (Entrained Gas) 5 Line (fluidizing gas) 6 Lines (particles) 7 Line (exhaust) 8 Line (Gas after cleaning) 9 Line (Solution containing dissolved dust) 10 Line (particles larger than product size) 11 Line (product size particles) 12 Line (particles smaller than product size) 13 Line (crushed particles) Line 14 (particles smaller than product size and crushed particles) 15 Line (Gas) 16 Line (Preheating gas) 17 Line (gas containing dust) 18 Internal piping (steam) 19 Next Door
Claims
1. A seed particle conditioning step (sc) of forming a fluidized bed of the seed particles and preheating the seed particles in the fluidized bed by supplying a preheating gas from below to the seed particles, and A granulation step (gr) of granulating by coating a coating material on the surface of the seed particles heated in the seed particle conditioning step (sc) in a high-temperature atmosphere The method for processing particles has seed particles being urea particles, the coating material being urea, the temperature of the preheating gas being 80°C to 140°C, and the temperature of the gas forming the high-temperature atmosphere in the granulation step (gr) being 80°C to 140°C.
2. The method for processing particles according to Claim 1, wherein the temperature of the preheating gas is the same as the temperature of the atmosphere in the granulation step (gr).
3. The method for processing particles according to Claim 1, wherein the temperature of the preheating gas is 90°C to 120°C, and the temperature of the gas forming the high-temperature atmosphere in the granulation step (gr) is 95°C to 120°C.
4. A seed particle conditioning device (SC) that forms a fluidized bed of the seed particles and preheats the seed particles in the fluidized bed by supplying a preheating gas from below to the seed particles, and A granulation device (GR) that granulates by coating a coating material on the surface of the seed particles heated by the seed particle conditioning device (SC) in a high-temperature atmosphere The particle processing device has seed particles being urea particles, the coating material being urea, the temperature of the preheating gas being 80°C to 140°C, and the temperature of the gas forming the high-temperature atmosphere in the granulation device (GR) being 80°C to 140°C.
5. A seed particle conditioning region (SCZ) that forms a fluidized bed of the seed particles and preheats the seed particles in the fluidized bed by supplying a preheating gas from below to the seed particles, and A granulation region (GRZ) that granulates by coating a coating material on the surface of the seed particles heated in the seed particle conditioning region (SCZ) in a high-temperature atmosphere The particle processing device has a seed particle conditioning and granulation device (SC / GR) including the above, seed particles being urea particles, the coating material being urea, the temperature of the preheating gas being 80°C to 140°C, and the temperature of the gas forming the high-temperature atmosphere in the granulation region (GRZ) being 80°C to 140°C.
6. An improved method for an existing particle processing device having a granulation device (GR) that granulates by coating a coating material on the surface of the seed particles in a high-temperature atmosphere, A seed particle adjusting device (SC) that forms a fluidized bed of the seed particles by supplying a preheating gas from below to the seed particles and preheats the seed particles in the fluidized bed is added to the existing particle processing device. In the granulation device (GR), granulation is performed by coating a coating material on the seed particles heated by the seed particle adjusting device (SC) in a high-temperature atmosphere, or A seed particle adjusting and granulating device (SC / GR) including a seed particle adjusting region (SCZ) that forms a fluidized bed of the seed particles by supplying a preheating gas from below to the seed particles and preheats the seed particles in the fluidized bed, and a granulation region (GRZ) that granulates by coating a coating material on the surface of the seed particles heated in the seed particle adjusting region (SCZ) in a high-temperature atmosphere is exchanged with the granulation device (GR). In the granulation region (GRZ), granulation is performed by coating a coating material on the seed particles heated by the seed particle adjusting region (SCZ) in a high-temperature atmosphere An improved method for an existing particle processing device, characterized in that the seed particles are urea particles, the coating material is urea, the temperature of the preheating gas is 80°C to 140°C, and the temperature of the gas forming the high-temperature atmosphere is 80°C to 140°C.