Powder supply device and liquid adding device

Abstract

To supply moist powder having liquid uniformly dispersed into dry powder, to the next step.SOLUTION: A liquid adding device is provided with: a casing which has an upper inlet port into which dry powder is put and a lower outlet port which ejects moist powder; a roller pair, arranged between the upper inlet port and the lower outlet port in the casing, which have roller shafts which are parallel to each other and whose peripheral surfaces face each other with a gap; a motor that rotationally drives the roller pair so that the roller pair drags the dry powder into the gap to apply a pressure and then feeds the powder downward; and a liquid supply nozzle, arranged in the casing, which has a plurality of nozzle outlets dispersed in the extending direction of the roller shafts and adds liquid to the dry powder which is not yet drawn into the gap through the plurality of nozzle outlets.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a powder supply device for supplying a powder raw material to a granulator and a liquid addition device included in the powder supply device.

Background Art

[0002] A granulator for forming a powder raw material into granules is used together with a powder supply device for supplying the powder raw material to the granulator. The powder raw material supplied to the granulator is a wet powder obtained by mixing a dry powder and a liquid such as a binder or a solvent. Therefore, the powder supply device is configured to mix the dry powder and the liquid and send out the powder raw material that has become a wet powder by the mixing. Patent Document 1 discloses a kneading granulator including this type of powder supply device.

[0003] The kneading granulator of Patent Document 1 includes a kneading case in which a kneading operation of kneading a dry powder and a binder solution to form a wet powder is performed, and a granulating case in which a granulating operation of forming the wet powder into granules is performed, and continuously supplies the powder raw material to the granulating case and granulates it. A kneading screw is disposed in the horizontally installed kneading case. Further, the kneading case is provided with a supply hole for the dry powder and a supply hole for the binder solution, respectively. The kneading case and its accessories correspond to the powder supply device. The dry powder and the binder solution supplied to the kneading case are mixed while advancing by the rotating kneading screw, thereby becoming a wet powder and being quantitatively supplied to the granulating case. The wet powder supplied to the granulating case is continuously extruded from the holes of the die by the rotating extrusion blades and granulated.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When a liquid binder is used as in Patent Document 1, the dry powder and the binder are mixed in a powder supply device. A powdery binder may be used. In this case, in the powder supply device, a liquid binder inducer such as water or alcohol is mixed with the dry powder in which the powdery binder has been previously mixed. In either case, it is difficult for a conventional powder supply device to uniformly mix the dry powder and the liquid (i.e., the liquid binder or the binder inducer) that binds the dry powder.

[0006] In the structure in which a liquid is dropped from above the screw onto the dry powder conveyed by the screw as in Patent Document 1, depending on the characteristics of the dry powder, the resistance may increase downstream of the liquid dropping position, making it difficult to send out the powder raw material with the screw. For example, a dry powder obtained by pulverizing a liquid such as an extract has the property of being easily soluble in water. When a liquid is added to such a dry powder having such a property, the portion in contact with the liquid immediately dissolves and adheres to the screw, and the liquid does not spread over the dry powder. In addition, wet powder with a large amount of moisture is not only difficult to convey with a screw due to its high viscosity, but also adheres to the walls of the path from the screw to the granulator and inside the granulator, causing poor granulation.

[0007] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a technique for supplying a wet powder in which a liquid is uniformly dispersed in a dry powder to the next process such as a granulator.

Means for Solving the Problems

[0008] In order to solve the above problems, a liquid addition device according to an aspect of the present disclosure includes a casing having an upper inlet into which dry powder is introduced and a lower outlet for discharging wet powder, a pair of rollers disposed vertically between the upper inlet and the lower outlet in the casing, having parallel roller shafts and facing each other with a gap between their peripheral surfaces, a motor that rotationally drives the pair of rollers so that the pair of rollers entrain and pressurize the dry powder into the gap and send it downward, It is provided with a liquid supply nozzle that is disposed inside the casing, has a plurality of nozzle outlets dispersed in the extending direction of the roller shaft, and adds a liquid to the dry powder before it is drawn into the gap from the plurality of nozzle outlets.

[0009] In order to solve the above problems, a powder supply device according to one aspect of the present disclosure a hopper for storing the dry powder; a liquid addition device that is disposed below the hopper and into which the dry powder is introduced from the hopper.

Advantages of the Invention

[0010] According to the present disclosure, it is possible to provide a technique capable of supplying a wet powder in which a liquid is uniformly dispersed in a dry powder to the next process.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0012] Next, embodiments of the present disclosure will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a continuous powder processing system 1 including a powder supply device 2 according to one aspect of the present disclosure.

[0013] [Schematic Configuration of Powder Processing System 1] The powder processing system 1 shown in Fig. 1 includes a mixer 5, a powder supply device 2, a granulator 3, a dryer 4, and a recovery device 6.

[0014] The mixer 5 mixes raw materials to form dry powder 11. The powder supply device 2 mixes the dry powder 11 supplied from the mixer 5 and the liquid binder 12 to form a wet powder containing liquid, that is, wet powder 13. Further, the powder supply device 2 quantitatively supplies the wet powder 13 to the granulator 3. The structure of the powder supply device 2 will be described in detail later. The granulator 3 forms the wet powder 13 supplied from the powder supply device 2 into granules. As a non-limiting example of the granulator 3, an extrusion granulator including a screen having a large number of holes and an extrusion blade for extruding the wet powder 13 from the screen can be mentioned. The dryer 4 dries the granules 14 obtained by granulating the wet powder 13 in the granulator 3. As a non-limiting example of the dryer 4, a fluidized bed dryer that fluidizes the granules 14 by bringing hot air introduced into the casing into contact with the granules 14 can be mentioned. The recovery device 6 recovers the granules 14 dried by the dryer 4 as products. As a non-limiting example of the recovery device 6, a cyclone that separates and recovers the granules 14 conveyed by the hot air from the dryer 4 can be mentioned.

[0015] [Structure of Powder Supply Device 2] Next, the structure of the powder supply device 2 will be described in detail. Fig. 2 is a side view of the powder supply device 2, and Fig. 3 is a view taken in the direction of arrow III in Fig. 2. However, the support base 50 is omitted in Fig. 3. As shown in Figs. 2 and 3, the powder supply device 2 includes a hopper 20, a liquid addition device 30, a support base 50, and a controller 60.

[0016] 《Hopper 20》 Hopper 20 is a container for temporarily storing the dry powder 11. Hopper 20 has an upper inlet 21 at the upper part of the container and a lower outlet 22 at the lower part of the container. The dry powder 11 supplied from the mixer 5 is introduced into the hopper 20 through the upper inlet 21 and discharged downward from the lower outlet 22. Inside the hopper 20, stirring blades 24 driven intermittently or continuously by a motor 23 are arranged. By the rotation of the stirring blades 24, the dry powder 11 inside the hopper 20 is stirred, and the decrease in the fluidity of the dry powder 11 due to powder pressure and friction is suppressed.

[0017] 《Liquid addition device 30》 A liquid addition device 30 is arranged directly below the hopper 20. The liquid addition device 30 includes a casing 33 having an upper inlet 31 and a lower outlet 32. The upper inlet 31 of the casing 33 is connected to the lower outlet 22 of the hopper 20. The dry powder 11 discharged from the lower outlet 22 of the hopper 20 falls by gravity and is introduced into the casing 33 through the upper inlet 31 of the casing 33.

[0018] Figure 4 is a sectional view taken along line IV-IV of the liquid addition device 30 in Figure 2, Figure 5 is a sectional view taken along line V-V of the liquid addition device 30 in Figure 3, and Figure 6 is a sectional view taken along line VI-VI of the liquid addition device 30 in Figure 3. As shown in Figures 4 to 6, an introduction cylinder 311 extending downward from the upper inlet 31 is provided inside the casing 33. The introduction cylinder 311 is formed by a liner 41 or the like covering the inner wall of the casing 33. Also, a discharge cylinder 321 extending upward from the lower outlet 32 is provided inside the casing 33. The discharge cylinder 321 is formed by a liner 42 or the like covering the inner wall of the casing 33. The surfaces of the liners 41 and 42 forming the introduction cylinder 311 and the discharge cylinder 321 are made of materials to which powders such as polymer polyethylene and fluororesin hardly adhere.

[0019] Inside the casing 33, a pair of rollers 8 is arranged between the upper and lower parts of the input cylinder 311 and the discharge cylinder 321. The pair of rollers 8 consists of a first roller 81 and a second roller 82. The extending direction (hereinafter referred to as the "roller axis direction") of the two roller shafts (i.e., the rotating shafts) A1 and A2 of the pair of rollers 8 is substantially horizontal. The two roller shafts A1 and A2 of the pair of rollers 8 are parallel, and the direction connecting the two roller shafts A1 and A2 (hereinafter referred to as the "inter-axis direction") is substantially horizontal. The distance between the two roller shafts A1 and A2 of the pair of rollers 8 is slightly larger than the sum of the radii of the first roller 81 and the second roller 82, and the circumferential surfaces of the first roller 81 and the second roller 82 face each other with a slight gap. The gap between the first roller 81 and the second roller 82 is hereinafter referred to as the "roller gap G".

[0020] The first roller 81 and the second roller 82 are rotationally driven by independent motors 83 and 84 respectively. However, one motor may be provided for the pair of rollers 8, and the two rollers 81 and 82 may be rotationally driven by one motor. As shown in FIG. 4, the first roller 81 and the second roller 82 rotate in opposite directions so as to entrain the powder into the roller gap G and send it downward.

[0021] The inter-axis distance D between the two roller shafts A1 and A2 of the pair of rollers 8 is variable. As the inter-axis distance D of the pair of rollers 8 changes, the size of the roller gap G in the inter-axis direction changes. Thus, in the powder supply device 2 according to the present embodiment, by increasing or decreasing the inter-axis distance D of the pair of rollers 8, the size of the roller gap G in the inter-axis direction can be adjusted.

[0022] A non-limiting example of the roller gap G adjustment mechanism is as follows. As shown in FIGS. 5 and 6, two movable bases 71 and 72 are supported by the casing 33 so as to be movable in the axial direction. The two movable bases 71 and 72 are arranged in the axial direction with a tapered plate 73 sandwiched therebetween. A motor 83 is attached to the movable base 71. The output shaft of the motor 83 penetrates the movable base 71, the casing 33, and the seal plate 43a and protrudes into the casing 33, and is coupled to a first roller 81 disposed in the casing 33. Similarly, a motor 84 is attached to the movable base 72. The output shaft of the motor 84 penetrates the movable base 72, the casing 33, and the seal plate 43a and protrudes into the casing 33, and is coupled to a second roller 82 disposed in the casing 33. The two movable bases 71 and 72 are pressed in the axial direction by a compression spring 74 so that the tapered plate 73 is pressed from both sides in the axial direction by the two movable bases 71 and 72. In such a configuration, the distance in the axial direction between the two movable bases 71 and 72 changes according to the degree of insertion of the tapered plate 73 between the movable bases 71 and 72, and the axial distance D between the rollers 81 and 82 that move integrally with the movable bases 71 and 72 changes, and the size of the roller gap G changes. The degree of insertion of the tapered plate 73 can be adjusted by a gap adjustment screw 75. A long bolt 77 is loosely inserted into the tapered plate 73, and a collar 76 and a gap adjustment screw 75 are fitted onto the long bolt 77. By rotating the gap adjustment screw 75 and moving the gap adjustment screw 75 on the long bolt 77, the tapered plate 73 can be further inserted between the movable bases 71 and 72 to widen the roller gap G, or the tapered plate 73 can be retracted to narrow the roller gap G.

[0023] As shown in FIG. 4 and FIG. 5, the upper inlet 31 of the casing 33, the roller gap G, and the lower outlet 32 ​​of the casing 33 are arranged in a vertical direction. The outlet area of ​​the input tube 311 is accommodated between the two roller shafts A1 and A2 of the roller pair 8. As a result, the dry powder 11 that falls onto the circumferential surface of the roller pair 8 through the input tube 311 is guided to the area between the two roller shafts A1 and A2 of the roller pair 8. In addition, the roller pair 8 is sandwiched by seal plates 43a and 43b from both sides in the roller axial direction. The seal plates 43a and 43b block both ends of the roller pair 8 in the roller axial direction so that the dry powder 11 that falls onto the circumferential surface of the roller pair 8 does not spill out in the roller axial direction. Furthermore, the area between the outlet of the input tube 311 and the circumferential surface of the roller pair 8 in the vertical direction and between the two roller shafts A1 and A2 is blocked by a side plate 49. The side plate 49 prevents the dry powder 11 from diffusing outward in the axial direction of the roller.

[0024] The dry powder 11 fed into the upper inlet 31 of the casing 33 passes through the feed tube 311 and falls into a region sandwiched between the two roller shafts A1 and A2 of the roller pair 8. The dry powder 11 that has fallen onto the peripheral surface of the roller pair 8 moves toward the roller gap G by the rotation of the roller pair 8, is caught in (in other words, is bitten into) the roller pair 8 and pushed downward, falls through the discharge tube 321, and is discharged from the lower outlet 32.

[0025] Before the dry powder 11 is caught in the roller gap G, the binder 12 is supplied from the liquid supply nozzles 36 and 37. The powder supply device 2 according to the present embodiment includes a first liquid supply nozzle 36 called a center nozzle disposed directly above the roller gap G, and a second liquid supply nozzle 37 called a side nozzle disposed above each of the rollers 81 and 82. However, the powder supply device 2 may include either one of the first liquid supply nozzle 36 and the second liquid supply nozzle 37. The binder 12 is quantitatively supplied to the liquid supply nozzles 36 and 37 by a liquid supply mechanism. An independent liquid supply mechanism may be provided for each of the liquid supply nozzles 36 and 37, or one liquid supply mechanism may be provided for the liquid supply nozzles 36 and 37. As a non-limiting example of the liquid supply mechanism, as shown in FIG. 2, a combination of a liquid container 46 that stores the binder 12, a tube 45 that connects the liquid container 46 and the liquid supply nozzles 36 and 37, and a tube pump 47 that pumps the liquid passing through the tube 45 can be mentioned.

[0026] As shown in FIG. 5, the first liquid supply nozzle 36 is a tubular member extending in the roller axis direction. The liquid supply nozzle 36 is disposed in the charging cylinder 311. However, the liquid supply nozzle 36 may be disposed below the charging cylinder 311.

[0027] The first liquid supply nozzle 36 has a nozzle outlet that is the outlet of the binder 12. The nozzle outlet opens downward, and the binder 12 fed to the liquid supply nozzle 36 falls downward from the nozzle outlet. The binder 12 dripping from the nozzle outlet of the first liquid supply nozzle 36 falls onto the dry powder 11 immediately before entering the roller gap G of the roller pair 8 and adheres to the dry powder 11. The sides and the upper part of the first liquid supply nozzle 36 are covered with a nozzle cover 44. The nozzle cover 44 prevents contact between the liquid supply nozzle 36 and the powder and prevents blockage of the nozzle outlet.

[0028] The second liquid supply nozzle 37 is a tubular member extending in the roller axis direction, similar to the first liquid supply nozzle 36. The liquid supply nozzle 37 has a nozzle outlet which is the outlet of the binder 12. The nozzle outlet opens downward, and the binder 12 fed to the liquid supply nozzle 37 drops downward from the nozzle outlet. The binder 12 dripping from the nozzle outlet of the second liquid supply nozzle 37 drops onto the peripheral surfaces of the rollers 81 and 82, and then adheres to the dry powder 11 that has dropped onto the peripheral surfaces of the rollers 81 and 82.

[0029] The horizontal position of the second liquid supply nozzle 37 disposed above the first roller 81 is between the roller gap G and the roller axis A1 of the first roller 81, and is farther from the roller gap G than the charging cylinder 311. Similarly, the horizontal position of the second liquid supply nozzle 37 disposed above the second roller 82 is between the roller gap G and the roller axis A2 of the second roller 82, and is farther from the roller gap G than the charging cylinder 311. That is, the second liquid supply nozzle 37 is disposed outside the falling path of the dry powder 11 from the upper inlet 31. With such an arrangement of the second liquid supply nozzle 37, contact between the nozzle outlet of the liquid supply nozzle 37 and the dry powder 11 falling from the upper inlet 31 is avoided, and blockage of the nozzle outlet is prevented.

[0030] The first liquid supply nozzle 36 and the second liquid supply nozzle 37 may have a plurality of nozzle outlets dispersed in the extending direction of the liquid supply nozzles 36 and 37, that is, in the roller axis direction. The plurality of nozzle outlets are preferably arranged at substantially equal intervals. However, instead of the plurality of nozzle outlets, the first liquid supply nozzle 36 and the second liquid supply nozzle 37 may have a slit-shaped nozzle outlet extending in the extending direction of the liquid supply nozzles 36 and 37, that is, in the roller axis direction.

[0031] The binder 12 is fed to the first liquid supply nozzle 36 and the second liquid supply nozzle 37 so that the binder 12 is supplied in the form of droplets from the nozzle outlets of the first liquid supply nozzle 36 and the second liquid supply nozzle 37. For each of the liquid supply nozzles 36, 37, the nozzle flow rate is defined as the value obtained by dividing the supply amount of the binder 12 by the cross-sectional area of the nozzle outlet × the number of nozzle outlets. When the nozzle flow rate is less than a predetermined first threshold value, the binder 12 exiting from the nozzle outlet is in the form of droplets. When the nozzle flow rate is equal to or greater than the first threshold value and less than a predetermined second threshold value, the binder 12 exiting from the nozzle outlet is in a state where droplets and a water flow are mixed. When the nozzle flow rate is equal to or greater than the second threshold value, the binder 12 exiting from the nozzle outlet is in the state of a water flow. If the binder 12 obtained from the nozzle outlet is in a state where a water flow and droplets are mixed, the flow of the binder 12 is not stable, so it is not suitable for liquid addition of the binder 12. Therefore, the binder 12 is supplied to the liquid supply nozzles 36, 37 so that the nozzle flow rate is less than a predetermined first threshold value or equal to or greater than the second threshold value. The above-mentioned first threshold value and second threshold value can be obtained in advance by experiments.

[0032] At the nozzle flow rate at which the binder 12 exiting from the nozzle outlet becomes droplets, since the liquid exiting from the adjacent nozzle outlets is connected by surface tension to form droplets, the number of nozzle outlets and the number of droplets do not necessarily match. However, if an excessive number of droplets are connected, the droplets will not be uniform throughout the nozzle, which is not suitable for liquid addition of the binder 12. Therefore, when supplying the binder 12 in the form of droplets from the liquid supply nozzles 36, 37, it is preferable to employ liquid supply nozzles 36, 37 having a nozzle outlet with a cross-sectional area such that, at the nozzle flow rate at which the binder 12 becomes droplets and without excessive connection of droplets, the droplets are uniform throughout the nozzle, with respect to the supply amount of the binder 12.

[0033] As described above, the binder 12 supplied from the first liquid supply nozzle 36 and the second liquid supply nozzle 37 adheres to the dry powder 11 before it enters the roller gap G. However, there are portions of the dry powder 11 to which the binder 12 adheres and portions to which it does not adhere, and the dispersion state of the binder 12 is non-uniform. The dry powder 11 with the non-uniformly dispersed binder 12 enters the roller gap G and is weakly compressed by being sandwiched between the roller pair 8 to such an extent that it does not solidify. As a result, the liquid region of the binder 12 expands, and the binder 12 penetrates the entire powder sandwiched between the roller pair 8 in the roller gap G. The powder after passing through the roller gap G has become a wet powder 13 in which the binder 12 is uniformly dispersed throughout the powder.

[0034] Most of the wet powder 13 after passing through the roller gap G automatically peels off from the circumferential surfaces of the rollers 81, 82 and falls, but a part may adhere to the circumferential surfaces of the rollers 81, 82 and remain. Therefore, below each of the rollers 81, 82, a scraper 39 is provided which contacts the circumferential surface of the roller 81, 82 and forcibly peels off the wet powder 13 adhering to the circumferential surface. The wet powder 13 peeled off from the circumferential surfaces of the rollers 81, 82 by the scraper 39 falls to the lower outlet 32 through the discharge cylinder 321. The scraper 39 according to the present embodiment is provided integrally with the liner 42 forming the discharge cylinder 321.

[0035] 《Support base 50》 The liquid addition device 30 on which the hopper 20 is placed is supported by the support base 50. The weight of the hopper 20 containing the powder and the liquid addition device 30 is applied to the support base 50. The support base 50 includes a load sensor 40 that detects the load received by the support base 50 from the hopper 20 containing the powder and the liquid addition device 30. The load sensor 40 is, for example, a load cell.

[0036] 《Controller 60》 The controller 60 includes, for example, a PLC (Programmable Logic Controller) having a CPU (Central Processing Unit), a memory, and a communication I / F for connecting to a communication network or other devices by wire or wirelessly, and a touch panel which is a user interface. Each function of the controller 60 can be realized by executing a predetermined program on the PLC.

[0037] A load sensor 40 is electrically connected to the controller 60, and the controller 60 acquires information related to the load detected by the load sensor 40. Also, motors 83 and 84 for driving the rollers 81 and 82 are electrically connected to the controller 60. The controller 60 includes a motor driver, and the motor driver operates the motors 83 and 84 based on commands related to the rotation speeds of the motors 83 and 84 generated by the PLC.

[0038] In the powder supply device 2 having the above configuration, the rotation speed of the roller pair 8 and the size of the roller gap G are variable. By changing at least one of the size of the roller gap G and the rotation speed of the roller pair 8, the discharge amount of the wet powder 13 of the powder supply device 2, that is, the supply amount of the wet powder 13 to the granulator 3 changes. The size of the roller gap G and the rotation speed of the roller pair 8 are adjusted according to the size and specific gravity of the dry powder 11, the liquid absorption characteristics of the dry powder 11, the supply amount of the dry powder 11, and the supply amount of the binder 12 so as to obtain a desired discharge amount of the wet powder 13.

[0039] During the operation of the powder supply device 2, the discharge amount of the wet powder 13 may vary due to fluctuations in the powder pressure of the dry powder 11. In such a case, fine adjustment of the discharge amount of the wet powder 13 is mainly performed by changing the rotation speeds of the rollers 81 and 82. For example, on the premise that the dry powder 11 is quantitatively supplied from the mixer 5 to the hopper 20 of the powder supply device 2, the controller 60 performs feedback control on the rotation speeds of the motors 83 and 84 so that the detection value of the load sensor 40 becomes constant. Thereby, stable quantitative supply of the wet powder 13 to the granulator 3 becomes possible.

[0040] In the powder processing system 1 according to the above-described embodiment, the liquid binder 12 is used. However, a powdered binder may be used. When a powdered binder is used, the raw material and the powdered binder are mixed by the mixer 5, and the dried powder 11 fed into the powder supply device 2 contains the powdered binder. With respect to the dried powder 11 containing the binder in this manner, instead of the liquid binder 12, a liquid binder inducer such as water or alcohol that induces binding of the dried powder 11 is added by the powder supply device 2.

[0041] 〔Summary〕 The liquid addition device 30 according to the first aspect of the present disclosure includes a casing 33 having an upper inlet 31 into which the dried powder 11 is fed and a lower outlet 32 through which the wet powder 13 is discharged, a roller pair 8 disposed between the upper inlet 31 and the lower outlet 32 in the vertical direction within the casing 33, having parallel roller shafts A1, A2, and having circumferential surfaces facing each other with a gap G therebetween, motors 83, 84 that rotationally drive the roller pair 8 so that the roller pair 8 entrains and pressurizes the dried powder 11 into the gap G and feeds it downward, and liquid supply nozzles 36, 37 disposed within the casing 33, having a plurality of nozzle outlets dispersed in the extending direction of the roller shafts A1, A2, and adding liquid to the dried powder 11 before it is entrained into the gap G from the plurality of nozzle outlets.

[0042] According to the liquid addition device 30 having the above-described configuration, the dry powder 11 in which the liquid (the binder 12 in the above embodiment) is unevenly dispersed enters the gap G between the roller pairs 8, and the liquid spreads over the dry powder 11 by being pressurized by the roller pairs 8, and becomes the wet powder 13 to which the liquid is uniformly adhered and is discharged from the gap G. In this way, the liquid is thinly and widely added to the dry powder 11, and by diffusing the liquid to the surrounding dry powder 11 by the pressurization by the roller pairs 8, the dry powder 11 can be uniformly wetted with the liquid. Further, even if the dry powder 11 has a property of being easily soluble in water, the liquid adhered to the dry powder 11 is immediately pressurized by the roller pairs 8, so that the liquid is dispersed to the surroundings, and dissolution of the powder can be suppressed. Furthermore, since there is no screw in the liquid addition device 30 of the present disclosure, wet powder with a large amount of moisture does not get entangled or adhered to the screw.

[0043] The liquid addition device 30 according to the second aspect of the present disclosure includes, in the liquid addition device 30 according to the first aspect, a first liquid supply nozzle 36 in which the liquid supply nozzles 36 and 37 are arranged directly above the gap G between the roller pairs 8.

[0044] In the liquid addition device 30 having the above-described configuration, the liquid is dropped from the first liquid supply nozzle 36 onto the dry powder 11 immediately before being drawn into the gap G between the roller pairs 8. Therefore, before the liquid completely penetrates into the dry powder 11, the liquid adhered with the liquid can be pressurized by the roller pairs 8. As a result, the moisture adhered to the dry powder 11 widely diffuses, and a wet powder 13 in which the liquid is more uniformly dispersed is obtained. Further, even if the dry powder 11 has a property of being easily soluble in water, since the liquid adhered to the dry powder 11 can be dispersed before the powder dissolves, dissolution of the powder can be suppressed.

[0045] The liquid addition device 30 according to the third aspect of the present disclosure further includes a nozzle cover 44 that covers above and laterally of the first liquid supply nozzle 36 in the liquid addition device 30 according to the second aspect.

[0046] In the liquid addition device 30 configured as described above, contact between the liquid supply nozzle 36 and the falling dry powder 11 is avoided, and clogging of the nozzle opening of the liquid supply nozzle 36 can be prevented.

[0047] The liquid addition device 30 according to the fourth aspect of the present disclosure is the liquid addition device 30 according to any one of the first to third aspects, wherein the liquid supply nozzles 36 and 37 are located between the roller shafts A1 and A2 of the roller pair 8 and above the peripheral surface of the roller pair 8 outside the falling path of the dry powder 11 from the upper inlet 31, and includes a second liquid supply nozzle 37.

[0048] In the liquid addition device 30 configured as described above, liquid is dripped from the second liquid supply nozzle 37 onto the peripheral surface of the roller pair 8, and the dry powder 11 falls onto the peripheral surface of the roller pair 8 to which the liquid adheres. Thereby, the liquid can be added to the dry powder 11 more uniformly as compared with the case where the liquid is directly dripped onto the dry powder 11.

[0049] The liquid addition device 30 according to the fifth aspect of the present disclosure is the liquid addition device 30 according to any one of the first to fourth aspects, and further includes a scraper 39 that is disposed in contact with the peripheral surface of the roller pair 8 below the roller pair 8 and peels off the deposits on the peripheral surface.

[0050] In the liquid addition device 30 configured as described above, the wet powder 13 that has adhered to the peripheral surface of the roller pair 8 without falling after passing through the gap G between the roller pairs 8 can be forcibly peeled off from the peripheral surface by the scraper 39 and discharged from the lower outlet 32.

[0051] The liquid addition device 30 according to the sixth aspect of the present disclosure is the liquid addition device 30 according to any one of the first to fifth aspects, wherein the axial distance D between the roller shafts A1 and A2 of the roller pair 8 is variable.

[0052] In the powder supply device 2 configured as described above, as the axial distance D between the roller shafts A1 and A2 of the roller pair 8 changes, the size of the gap G between the roller pair 8 changes. By changing the size of the gap G between the roller pair 8, the flow rate of the powder passing through the gap G can be increased or decreased, or the pressure applied to the powder passing through the gap G can be changed.

[0053] The powder supply device 2 according to the seventh aspect of the present disclosure includes a hopper 20 that stores the dry powder 11, and a liquid addition device 30 that is disposed below the hopper 20 and to which the dry powder 11 is introduced from the hopper 20 and that relates to any one of the first to sixth aspects.

[0054] In the powder supply device 2 configured as described above, the dry powder 11 stored in the hopper 20 is introduced into the liquid addition device 30, and a liquid is added to and mixed with the dry powder 11 in the liquid addition device 30 to form a wet powder 13, and the wet powder 13 is supplied from the liquid addition device 30 to the next process (i.e., the granulator 3). As described above, since a wet powder 13 in which the liquid is more uniformly dispersed can be obtained in the liquid addition device 30, the powder supply device 2 configured as described above can supply the wet powder 13 with a good dispersion state of the liquid to the next process.

[0055] The powder supply device 2 according to the eighth aspect of the present disclosure includes a support base 50 that supports the hopper 20 and the liquid addition device 30, a load sensor 40 that detects the load applied to the support base 50, and a controller 60 that changes the rotation speeds of the motors 83 and 84 of the liquid addition device 30 based on the detection value of the load sensor 40.

[0056] According to the powder supply device 2 configured as described above, by adjusting the rotation speeds of the motors 83 and 84 with the controller 60 so that the detection value of the load sensor 40 becomes constant, the wet powder 13 can be quantitatively supplied to the next process.

[0057] The functions implemented by the controller 60 described in this specification may be implemented in circuitry or processing circuitry including a general-purpose processor, an application-specific processor, an integrated circuit, ASICs (Application Specific Integrated Circuits), a CPU (Central Processing Unit), conventional circuitry, and / or combinations thereof, programmed to implement the described functions. The processor includes transistors and other circuitry and is considered circuitry or processing circuitry. The processor may be a programmed processor that executes a program stored in a memory. In this specification, circuitry, unit, and means are hardware programmed to implement the described functions or hardware that executes. The hardware may be any hardware disclosed in this specification or any hardware known to be programmed or execute to implement the described functions. When the hardware is a processor considered to be of the circuitry type, the circuitry, means, or unit is a combination of hardware and software used to configure the hardware and / or the processor.

[0058] The foregoing discussion of the present disclosure has been presented for purposes of illustration and description and is not intended to limit the present disclosure to the forms disclosed herein. For example, in the foregoing detailed description, various features of the present disclosure are grouped together in one embodiment for purposes of streamlining the disclosure, but some of the features may be combined. Also, multiple features included in the present disclosure may be combined in alternative embodiments, configurations, or aspects other than those discussed above.

Explanation of Reference Numerals

[0059] 2: Powder Feeding Device 8: Roller Pair 11: Dry Powder 12: Binder (an example of a liquid) 13: Wet powder 20: Hopper 30: Liquid addition device 31: Upper inlet 32: Lower outlet 33: Casing 36: First liquid supply nozzle 37: Second liquid supply nozzle 39: Scraper 40: Load sensor 44: Nozzle cover 50: Support stand 60: Controller 81, 82: Roller 83, 84: Motor A1, A2: Roller shaft D: Axial distance G: Roller gap

Claims

1. A casing having an upper inlet into which dry powder is introduced and a lower outlet through which wet powder is discharged, a pair of rollers disposed vertically between the upper inlet and the lower outlet in the casing, having parallel roller shafts and facing each other with a gap between their peripheral surfaces, a motor for rotationally driving the pair of rollers so that the pair of rollers entrain and pressurize the dry powder into the gap and feed it downward, and a liquid supply nozzle disposed in the casing, having a plurality of nozzle outlets dispersed in the extending direction of the roller shafts, and adding liquid to the dry powder before being entrained into the gap from the plurality of nozzle outlets. A liquid addition device.

2. The liquid addition device according to claim 1, wherein the liquid supply nozzle includes a first liquid supply nozzle disposed directly above the gap of the pair of rollers. The liquid addition device according to claim 1.

3. The liquid addition device according to claim 2, further comprising a nozzle cover covering above and laterally of the first liquid supply nozzle. The liquid addition device according to claim 2.

4. The liquid addition device according to claim 1, wherein the liquid supply nozzle includes a second liquid supply nozzle disposed between the roller shafts of the pair of rollers and above the peripheral surface of the pair of rollers deviating from the falling path of the dry powder from the upper inlet. The liquid addition device according to claim 1.

5. The liquid addition device according to claim 1, further comprising a scraper disposed in contact with the peripheral surface of the pair of rollers below the pair of rollers to peel off deposits on the peripheral surface. The liquid addition device according to claim 1.

6. The liquid addition device according to claim 1, wherein the axial distance between the roller shafts of the pair of rollers is variable. The liquid addition device according to claim 1.

7. A hopper for containing the dry powder, and the liquid addition device according to any one of claims 1 to 6 disposed below the hopper and into which the dry powder is introduced from the hopper. A powder supply device.

8. A support base for supporting the hopper and the liquid addition device, a load sensor for detecting a load applied to the support base, and a controller for changing the rotational speed of the motor of the liquid addition device based on a detection value of the load sensor. The powder supply device according to claim 7.

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