Powder Mixing Supply System

Abstract

To keep a percentage of respective powders for constituting mixed powder constantly within a desired range in a system for supplying to an apparatus for executing processing of a post-process by mixing a plurality of powders discharged by the plurality of respective power supply devices.SOLUTION: A system has a first power supply device for discharging by storing first powder and a second powder supply device for discharging by storing second powder, and has a control part for controlling to converge a flow rate of the powder discharged by the first powder supply device and a flow rate of the powder discharged by the second powder supply device in respective target values, for supplying mixed powder of mixing the powder discharged at a required ratio from both powder supply devices to an apparatus for executing processing of the post-process, and constitutes the control part for increasing-decreasing a discharge flow rate of the powder by the second powder supply device so that the ratio of the first powder and the second powder included in the mixed powder is maintained in a desired range when the discharge flow rate of the powder by the first powder supply device is deviated more than a prescribed value from its target value.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a powder mixing and supplying system for stably supplying a mixed powder obtained by mixing a first powder and a second powder in a required ratio. [Background technology]

[0002] In the past, at pharmaceutical tablet production sites, it was common to follow a batch-type procedure in which intermediate products were made from the powder components through processes such as granulation, drying, sizing, and mixing, and then the completed mixed powder was fed into a powder compression molding machine, where it went through the compression (tableting) process.

[0003] However, this batch method creates waiting times between processes. For example, to perform the compression process using a molding machine, a mixing process must be carried out first to mix the powder, and the powder produced by the mixing process must be replenished into the molding machine. During this time, the molding machine must stop operating and wait. In other words, it is difficult to supply intermediate products in a timely manner. In addition, there is the disadvantage that equipment design is required for each process, occupying a large space. More specifically, each process requires a separate room, and workers have to go through the trouble of transporting intermediate products from the room for the previous process to the room for the next process.

[0004] Therefore, in order to perform the powder mixing process and compression process continuously, a system was developed that supplies the mixed powder directly to a molding machine (see Patent Document 1 below). This system allows the mixed powder to be replenished to the molding machine at the appropriate time while the powder compression tableting process by the molding machine continues.

[0005] A powder mixing and supplying system that performs the powder mixing process has multiple powder supplying devices, each of which stores powder and discharges the stored powder.The powder discharged by each powder supplying device is mixed and then supplied to a molding machine or other equipment that performs subsequent processing.

[0006] A typical example of a powder supplying device is a constant-volume feeder (see Non-Patent Documents 1 and 2 below), which continuously discharges a fixed amount of powder per predetermined time. This device sends out powder that falls from a hopper storing the powder using a screw feeder, table feeder, circle feeder (registered trademark), rotary feeder, etc. The flow rate per unit time of the powder discharged by the screw feeder, etc. is measured using a measuring device, such as a load cell, and the motor that is the drive source of the screw feeder, etc. is feedback-controlled so that the discharge flow rate converges to a target value. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 6857896 [Non-patent literature]

[0008] [Non-Patent Document 1] "Feeders manufactured by Coperion K-Tron (COPERION K-TRON is a registered trademark (internationally registered))," [online], Apte Japan Co., Ltd., [searched June 20, 2021], Internet<URL:https: / / apte.jp / device / k-tron / > [Non-patent document 2] “Circle Feeder Principle,” [online], Yoshikawa Corporation, [Retrieved June 20, 2021], Internet<URL:https: / / www.yoshikawa-cf.co.jp / technology / archives / 25> Summary of the Invention [Problem to be solved by the invention]

[0009] In each powder supplying device, the amount of powder stored in the hopper gradually decreases as the powder is discharged. Naturally, the hopper must be replenished with powder from time to time. If the amount or density of powder in the hopper changes significantly, or if the flow rate of powder discharged by a powder supplying device fluctuates sharply due to other factors, the ratio of powder delivered by that powder supplying device to powder delivered by other powder supplying devices may deviate from the desired range. A mixed powder containing these powders will be a defective product that is unsuitable for delivery to downstream processing equipment, such as a molding machine.

[0010] The present invention is a method for mixing a plurality of powders discharged from a plurality of powder supplying devices. Rotary Powder Compression Molding Machine In a system that supplies powder to a customer, the ratio of each powder that makes up the mixed powder is constantly maintained within a desired range. and keep the molding machines running. This is the intended purpose. [Means for solving the problem]

[0011] In order to solve the above-mentioned problems, the present invention provides a rotary powder compression molding machine that has a first powder supplying device that stores and discharges a main drug and a second powder supplying device that stores and discharges a powder other than the main drug, and that mixes the main drug and the powder other than the main drug discharged from both powder supplying devices in a required ratio to compress the mixed powder and form tablets. Each of the first powder supplying device and the second powder supplying device has a hopper that stores powder, a transfer member that sends out the powder from the hopper to be discharged, a motor that drives the transfer member, and a measuring instrument that measures the amount of powder sent out and discharged by the transfer member, and a control unit that normally controls the flow rate of the main drug discharged by the first powder supplying device to a target value. and controlling the number of revolutions of the motor of the first powder supply device or the current or voltage applied to the motor coil so as to converge the flow rate of the powder other than the main agent discharged by the second powder supply device to its target value, and controlling the number of revolutions of the motor of the second powder supply device or the current or voltage applied to the motor coil so as to converge the flow rate of the powder other than the main agent discharged by the second powder supply device to its target value; setting a correction condition value for the discharge flow rate of the main agent that is close to the target value but is not the same as the target value and deviates from the target value, and an abnormality detection value that is farther away from the target value than the correction condition value; and when the flow rate of the main agent measured by the measuring instrument of the first powder supply device is between the target value and the correction condition value, maintaining the number of revolutions of the motor of the first powder supply device or the current or voltage applied to the motor coil without changing it. At the same time, the rotation speed of the motor of the second powder supply device or the current or voltage applied to the coil of the motor is controlled so that the discharge flow rate of the powder other than the main agent measured by the measuring device of the second powder supply device converges to a target value during normal operation. When the flow rate of the main agent measured by the measuring instrument of the first powder supplying device is between the correction condition value and the abnormality detection value, the rotation speed of the motor of the first powder supplying device or the current or voltage applied to the motor coil is adjusted so that the flow rate of the main agent falls between the target value and the correction condition value. At the same time, the rotation speed of the motor of the second powder supply device or the current or voltage applied to the coil of the motor is controlled so that the discharge flow rate of the powder other than the main agent measured by the measuring device of the second powder supply device converges to a target value during normal operation.If the flow rate of the main agent measured by the measuring instrument of the first powder supply device is not between its target value and the abnormality detection value, the rotation speed of the motor of the second powder supply device or the current or voltage applied to the motor coil is adjusted so that the ratio of the main agent to the powder other than the main agent contained in the mixed powder is maintained within a desired range, thereby increasing or decreasing the discharge flow rate of the powder other than the main agent measured by the measuring instrument of the second powder supply device from the normal target value, and the rotation speed of the turntable of the rotary powder compression molding machine is adjusted according to the flow rate of the mixed powder supplied to the rotary powder compression molding machine.This powder mixing supply system is configured.

[0012] In the present invention, when the flow rate of a first powder discharged by a first powder supplying device changes suddenly, the flow rate of a second powder discharged by a different second powder supplying device is increased or decreased to control the ratio of the first powder to the second powder so that it does not deviate from the desired range.

[0013] In particular, the second powder supplying device may comprise a powder supplying device that stores and discharges an excipient, and a powder supplying device that stores and supplies a lubricant, and when the flow rate of the main drug measured by the measuring device of the first powder supplying device is not between its target value and the abnormality detection value, the system may increase or decrease the discharge flow rate of the excipient measured by the measuring device of the second powder supplying device from its normal target value and / or increase or decrease the discharge flow rate of the lubricant from its normal target value, and may also adjust the rotation speed of the turntable of the rotary powder compression molding machine in accordance with the flow rate of the mixed powder supplied to the rotary powder compression molding machine. .

[0014] By such control, the powder discharged by the first powder supplying device Main drug The difference between the flow rate and its target value is relatively small ( Main drug When the discharge flow rate does not exceed the abnormal detection value, Main drug The discharge flow rate of the second powder supply device is adjusted. Other than the main drug Without increasing or decreasing the powder flow rate, Main drug and Other than the main drug The amount of mixed powder per unit time that is supplied by mixing the powders mentioned above with each other is prevented from fluctuating greatly. Main drug The difference between the discharge flow rate and the target value became large ( Main drug If the discharge flow rate exceeds the abnormal detection value, Other than the main drug The discharge flow rate of the powder contained in the mixed powder is increased or decreased. Main drug and Other than the main drug The ratio of the powder to the powder is kept within a desired range, so that the supply of the mixed powder to the equipment performing the subsequent processing can be continued without interruption.

[0015] The term "powder" refers to an aggregate of minute particles, and is a concept that encompasses aggregates of particles such as so-called granules, as well as aggregates of powders smaller than particles. Specific examples of powders include powders containing a main ingredient, as well as excipients, binders, disintegrants, stabilizers, preservatives, etc. Powders containing two or more types of powders are also considered to be a type of powder in the present invention, and powders containing a main ingredient mixed with a lubricant such as magnesium stearate also fall under the category of powder. [Effects of the Invention]

[0016] According to the present invention, a plurality of powders discharged from a plurality of powder supplying devices are mixed together to form a powder mixture. Rotary Powder Compression Molding Machine In a system that supplies powder to a customer, the ratio of each powder that makes up the mixed powder is constantly maintained within a desired range. and keep the molding machines running. This becomes possible. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a side cross-sectional view of a powder compression molding machine according to an embodiment of the present invention. [Figure 2] FIG. 2 is a plan view of a main part of the powder compression molding machine according to the embodiment. [Figure 3] FIG. 2 is a cylindrical view of the powder compression molding machine according to the embodiment. [Figure 4] FIG. 2 is a side view schematically showing the configuration of a powder compression molding machine and a powder mixing and supplying system in the embodiment. [Figure 5] FIG. 2 is a side view showing a powder supplying device which is an element of the powder mixing supplying system of the embodiment. [Figure 6] 3A and 3B are diagrams illustrating the contents of control by a control unit of the powder mixing supply system according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] An embodiment of the present invention will be described below with reference to the drawings. First, an outline of a rotary powder compression molding machine (hereinafter referred to as "molding machine") A will be described as an example of equipment that performs post-processing using a mixed powder discharged and supplied by a powder supplying device of this embodiment.

[0019] Molding machine A is a machine that fills mixed powder into a die hole 4 and compresses the powder with punches 5 and 6 to mold pharmaceutical tablets, food products, electronic components, etc. As shown in Figure 1, a vertical shaft 2 that serves as a rotation axis is installed within a frame 1 of molding machine A, and a turntable 3 is attached to the top of the vertical shaft 2 via a connection part 21.

[0020] The turntable 3 rotates horizontally, i.e., spins on its own axis, around the axis of the vertical shaft 2. The turntable 3 is composed of a table (mill disk) 31, an upper punch holder 32, and a lower punch holder 33. As shown in FIG. 2, the table 31 is substantially disk-shaped, and a plurality of mill holes 4 are formed at predetermined intervals along the rotational direction on its outer periphery. The mill holes 4 penetrate the table 31 in the vertical direction. The table 31 may be divided into a plurality of plates. Furthermore, instead of directly drilling the mill holes 4 in the table 31 itself, a configuration may be adopted in which a plurality of mill members that are separate from the table 31 and detachable from the table 31 are attached to the table 31, and a mill hole that penetrates the table 31 in the vertical direction is drilled in each of the mill members.

[0021] An upper punch 5 and a lower punch 6 are arranged above and below each die hole 4. The upper punch 5 and the lower punch 6 are held by an upper punch holder 32 and a lower punch holder 33 so that they can each slide up and down independently relative to the die hole 4. The punch tip 53 of the upper punch 5 moves in and out of the die hole 4. The punch tip 63 of the lower punch 6 is always inserted in the die hole 4. The upper punch 5 and the lower punch 6 rotate horizontally, i.e., revolve, around the axis of the vertical shaft 2 together with the turntable 3 and the die hole 4.

[0022] A worm wheel 7 is attached to the lower end of the vertical shaft 2. A worm gear 10 meshes with the worm wheel 7. The worm gear 10 is fixed to a gear shaft 9 driven by a motor 8. The driving force output by the motor 8 is transmitted to the gear shaft 9 by a belt 11, and drives the vertical shaft 2, the turntable 3, and the punches 5 and 6 to rotate via the worm gear 10 and the worm wheel 7.

[0023] Powder, which is the raw material for a compression-molded product, such as a pharmaceutical tablet, is filled into the die hole 4 through a feeder A1, which is a filling device. There are two types of feeder A1: an agitating feeder and an open feeder, and either type can be used. To supply the powder to the feeder A1, a powder mixing and supplying system B including a powder supplying device, which will be described later, is used. The powder mixing and supplying system B is detachable from the molding machine A.

[0024] 2 and 3, on the revolution orbit of the punches 5, 6 around the axis of the vertical shaft 2, there are a pair of pre-pressing upper roll 12 and pre-pressing lower roll 13, and a pair of main pressure upper roll 14 and main pressure lower roll 15, which sandwich the punches 5, 6. The pre-pressing upper roll 12 and pre-pressing lower roll 13, and the main pressure upper roll 14 and main pressure lower roll 15 urge the upper and lower punches 5, 6 in a direction to move closer to each other so that the powder filled in the die hole 4 is compressed from above and below by the tip surfaces of the punch tips 53, 63.

[0025] The upper punch 5 and the lower punch 6 have heads 51 and 61 pressed by the rolls 12, 13, 14, and 15, respectively, and body portions 52 and 62 having a smaller diameter than the heads 51 and 61. The upper punch holding portion 32 of the turntable 3 holds the body portion 52 of the upper punch 5 so that it can slide up and down, and the lower punch holding portion 33 holds the body portion 62 of the lower punch 6 so that it can slide up and down. The tip portions 53 and 63 of the body portions 52 and 62 are thinner than the other portions so that they can be inserted into the die bore 4, and have a diameter approximately equal to the inner diameter of the die bore 4. As the punches 5 and 6 revolve, the rolls 12, 13, 14, and 15 approach the heads 51 and 61 of the punches 5 and 6 and come into contact with them by climbing up onto the heads 51 and 61. Furthermore, the rolls 12, 13, 14, and 15 press the upper punch 5 downward and the lower punch 6 upward. While the rolls 12, 13, 14, and 15 are in contact with the flat surfaces of the punches 5 and 6, the punches 5 and 6 continue to apply a constant pressure to the powder in the die cavity 4.

[0026] The product discharge section is located further in the direction of rotation of the turntable 3 and punches 5, 6 than the pressure position applied by the main pressure upper roll 14 and main pressure lower roll 15. Here, the lower punch 6 rises until the upper end surface of the punch tip 63 of the lower punch 6 is at approximately the same height as the upper end of the die hole 4, i.e., the upper surface of the table 31, and the molded product inside the die hole 4 is pushed out of the die hole 4. A damper 17 is provided at the product discharge section to guide the molded product pushed out of the die hole 4. The molded product pushed out of the die hole 4 comes into contact with the damper 17 as the turntable 3 rotates, and moves along the damper 17 toward a molded product recovery position 18.

[0027] Next, we will describe the configuration of powder mixed supply system B in this embodiment. This powder mixed supply system B serves to supply mixed powder to equipment that performs post-processing, in this case molding machine A, and as shown in Figure 4, it includes constant-volume feeders B1, B2, and B3, which are multiple powder supply devices that store and discharge the stored powder, and mixers B4 and B5 that mix the powder discharged from each of the multiple constant-volume feeders B1, B2, and B3 and then discharge the mixed powder.

[0028] This powder mixing and supplying system B is equipped with three fixed-volume feeders B1, B2, and B3. However, the number of feeders B1, B2, and B3 varies depending on the number of types of powder to be mixed, and may be two, four, or more. Each feeder B1, B2, and B3 may discharge different types of powder or the same type of powder. The powder discharged by feeders B1, B2, and B3 may be a pre-mixed mixture of multiple powders. Examples of types of powder include powders containing active ingredients, excipients, binders, disintegrants, lubricants, stabilizers, preservatives, etc. In this embodiment, feeder B1, which is a first powder supplying device, ejects and supplies the first powder, which is the main ingredient; feeder B2, which is a second powder supplying device, ejects and supplies the second powder, which is an excipient such as lactose or other powder; and feeder B3, which is a second powder supplying device, ejects and supplies the second powder, which is a lubricant such as magnesium stearate.

[0029] Mixers B4 and B5 consist of a vertical mixer B4 and a horizontal mixer B5 connected downstream. The vertical mixer B4 mixes the powder (i.e., the active ingredient) discharged by feeder B1 with the powder (i.e., excipient or other powder) discharged by feeder B2, dropping the mixture toward the horizontal mixer B5. The vertical mixer B4 has a funnel-shaped case B41, a vertical or nearly vertical agitator shaft B42 that rotates on its own axis and is located in the center of the case, an agitator blade B43 attached integrally to the agitator shaft, and a motor B44 that rotates the agitator shaft B42 and agitator blade B43.

[0030] The powders discharged from feeder B1 and feeder B2 are dropped from above into the case of vertical mixer B4. The powders come into contact with rotating agitator blade B43 and move downward within case B41 while being agitated by the agitator blade B43. A number of holes (not shown) that penetrate case B41 are pre-drilled in the bottom of case B41, and the mixed powder agitated within case B41 flows out of case B41 through these holes. The mixed powder then flows into horizontal mixer B5 through connection port B45.

[0031] The horizontal mixer B5 mixes the powders mixed in the vertical mixer B4, i.e., the main drug and excipients or other powders, with the powders discharged by the feeder B3, i.e., the lubricant, and transfers them toward the feeder A1 of the molding machine A. The horizontal mixer B5 has a cylindrical case B51 extending horizontally or approximately horizontally, a horizontal or approximately horizontal agitator shaft B52 located in the center of the case B51 and rotating on its own axis, an agitator blade B53 attached to the agitator shaft B52, and a motor B54 that rotates the agitator shaft B52 and agitator blade B53.

[0032] The outer end of the case B51 is provided with an inlet B511 that connects to the connection port of the vertical mixer B4. The inner end of the case B51 is provided with a discharge port B512 that connects the inside and outside of the feeder A1 and connects to the supply port A11 for supplying powder to the feeder A1. Furthermore, the middle of the case B51 is provided with an inlet B513 that connects to the feeder B3. The agitator shaft B52 and agitator blade B53 rotate while in contact with the powder to be mixed, mixing the powder and transporting the powder in a direction intersecting the vertical direction. These agitators B52 and B53 extend to just before the discharge port B512, which is the end of the mixers B4 and B5.

[0033] The powder mixed in the vertical mixer B4 is fed from the connection port B45 through the receiving port B511 into the case B51 of the horizontal mixer B5. The powder comes into contact with the rotating agitator blade B53 and moves from the outside to the inside of the case B51 while being agitated by the agitator blade B53. During this process, powder discharged from the feeder B3 is fed into the case B51 through the receiving port B513 and further agitated by the agitator blade B53. As a result, the main ingredient supplied by the feeder B1, the excipient or other powder supplied by the feeder B2, and the lubricant supplied by the feeder B3 are mixed within the case B51 and transported along the case B51. Finally, this mixed powder is discharged from the discharge port B512 and supplied to the feed port A11 of the feeder A1 of the molding machine A. The feeder A1 fills the mixed powder supplied to its feeding port A11 into the die hole 4 drilled in the table 31.

[0034] A sensor (not shown) is installed in advance in the feeder A1 to measure the mixing degree of the mixed powder supplied from the powder mixing supply system B. Various methods for measuring the mixing degree of powders include Raman spectroscopy, infrared spectroscopy, X-ray diffraction, X-ray transmission measurement, and high-performance liquid chromatography (HPLC). Any method capable of measuring the mixing degree in real time is acceptable. For example, near-infrared spectroscopy (NIR, or near-infrared absorption spectroscopy) is used to evaluate the amount or proportion (ratio) of the active ingredient in the mixed powder, in other words, the homogeneity of the mixed powder (whether segregation occurs). Near-infrared spectroscopy irradiates the moving mixed powder with near-infrared light, measures the absorption and scattering of light, and performs qualitative and quantitative analysis of the active ingredient concentration and other parameters using the spectrum, repeating this process at a predetermined interval. The measurement wavelength is a wavelength band that has no peaks for excipients or lubricants and is the specific absorption peak of the active ingredient. Near-infrared spectroscopy can also be used to measure the particle size of the mixed powder. When near-infrared spectroscopic analysis is employed, a near-infrared sensor is installed in the feeder A1 as a PAT (Process Analytical Technology) sensor that measures the degree of mixing of powders, etc.

[0035] In addition, the product discharge section of molding machine A is provided with a molded product rejection mechanism W for sorting out specific molded products, such as defective products or sample products, from a group of molded products to be collected at molded product collection position 18. Specifically, an air passage 16 for circulating pressurized air is formed inside damper 17, and the tip of this air passage 16 is an air injection nozzle 16a that opens outward in the radial direction of turntable 3. A control valve 22 for opening and closing passage 20 is installed on flow path 20 that connects an air supply source (not shown), such as a pump, that supplies pressurized air to air passage 16. Control valve 22 is, for example, an electromagnetic solenoid that opens and closes in response to a control signal given from a control device.

[0036] When the control valve 22 is opened as a specific molded product extruded from the die bore 4 passes near the air injection nozzle 16a before coming into contact with the damper 17, pressurized air supplied from the air supply source is ejected from the air injection nozzle 16a via the flow path 20 and the air passage 16 in the damper 17. This ejected air blows the specific molded product outward from the table 31. The blown-away molded product does not reach the molded product recovery position 18 located further along the damper 17. Thus, in this molding machine A, the flow passages 16, 20 for the air supplied from the air supply source, the injection nozzle 16a, and the control valve 22 constitute a molded product removal mechanism W.

[0037] If the composition or degree of mixing of the powder mixture measured by a near-infrared sensor or the like attached to the feeder A1 is found to be inappropriate, the powder mixture is first loaded from the feeder A1 into the die hole 4 of the table 31 of the molding machine A, and then compressed into a molded product by the upper punch 5 and the lower punch 6. The molded product is then removed by the molded product removal mechanism W before reaching the molded product recovery position 18. That is, in the molding machine A, when the die hole 4 filled with the defective powder mixture and into which the molded product has been tableted passes near the air injection nozzle 16a, the control valve 22 is opened and air is injected from the air injection nozzle 16a to blow the molded product out of the table 31. At the same time, an alarm may be sounded, the device may be stopped, etc.

[0038] When connecting the powder mixing supply system B to the molding machine A, the inner end of the case B51 of the horizontal mixer B5 and the discharge port B512 are inserted into the frame 1 of the molding machine A. Meanwhile, the other elements of the powder mixing supply system B, i.e., the parts of the horizontal mixer B5 other than the inner end of the case B51, the vertical mixer B4, and the constant feeders B1, B2, and B3, remain outside the frame 1 of the molding machine A. Casters B7 are attached to the bottom of the support body (frame or housing) B6 of the powder mixing supply system B that supports the constant feeders B1, B2, and B3, the vertical mixer B4, and the horizontal mixer B5, to enable the powder mixing supply system B to be easily moved.

[0039] The following provides additional information regarding the structure of constant-volume feeders B1, B2, and B3. As shown in Figure 5, each of feeders B1, B2, and B3 includes a hopper B01 for storing powder, a transfer mechanism B02 for delivering the powder from the hopper B01 so that it can be discharged, a supply mechanism B03 for supplying powder to the hopper B01 at appropriate times, a measuring device B04 for measuring the discharge flow rate per unit time of the powder discharged by the transfer mechanism B02, and a control unit B05 for controlling the transfer mechanism B02 so that the discharge flow rate of the powder converges to a required target value.

[0040] The transfer mechanism B02 includes a transfer member B021 that contacts and delivers powder falling from the hopper B01, and a motor B022 that rotates and drives the transfer member B021. The transfer mechanism B02 can be, for example, a known screw feeder, table feeder, circle feeder, disk feeder, or rotary feeder. The transfer member B021 in the screw feeder B02 is a screw blade with spiral blades attached to a shaft that rotates around its axis, and transfers powder captured between the blades along the axis. The transfer members in the table feeder, circle feeder, disk feeder, and rotary feeder are a rotating table, flat bar (rotating blade), disk, and rotor (built into a rotary valve), respectively. In this embodiment, a screw feeder is used as the transfer mechanism B02. The rotation speed of the motor B022 that drives the transfer member B021 affects the flow rate per unit time of the powder delivered by the transfer mechanism B02. In principle, the higher the rotation speed of the motor B022, the greater the flow rate of the powder delivered per unit time.

[0041] The motor B022 (and the motor B032 of the supply mechanism B03 described below) is, for example, a DC (direct current) motor, particularly a brushless DC motor. The basic characteristics of a DC motor are: V M =I a R a +E a E a =K e N T=Kt I a =-(K t K e N) / R a +(K t V M ) / R a where V M is the power supply voltage applied to the coil of the DC motor, I a is the current flowing through the coil of the DC motor, R a is the armature resistance, E a is the back electromotive force voltage, T is the torque generated by the DC motor, K t is the torque constant, K e is the back electromotive force constant, and N is the rotation speed of the DC motor.

[0042] The supply mechanism B03 is, for example, a known rotary feeder, and is located above the hopper B01. It stores a large amount of powder to be supplied to the hopper B01. A rotary valve B031 is installed below the supply mechanism B03, facing the hopper B01. When the amount of powder in the hopper B01 decreases to a predetermined lower limit, the supply mechanism B03 opens the rotary valve B031 to feed the stored powder into the hopper B01. When the amount of powder in the hopper B01 recovers to a predetermined upper limit, the rotary valve B031 is closed to prevent any further powder from being fed into the hopper B01.

[0043] The measuring instrument B04 repeatedly detects the current weight of the hopper B01 and the powder stored in the hopper B01. The value subtracted from this weight is the powder discharge amount of the constant-weight feeders B1, B2, and B3. The measuring instrument B04 may be, for example, a load cell, which is a strain gauge sensor, a tuning fork force sensor, or a force balance sensor. The supply mechanism B03 and the hopper B01 are connected via, for example, a bellows joint B033, so that the weight of the supply mechanism B03 and the weight of the powder stored in the supply mechanism B03 (before being supplied to the hopper B01) are not added to the hopper B01. In other words, the measuring instrument B04 does not detect the weight of the supply mechanism B03 or the powder stored in the supply mechanism B03.

[0044] The control unit B05 receives an output signal from the measuring device B04 to determine the weight of powder currently stored in the hopper B01, and controls a motor B022 that drives a transfer member (i.e., a screw blade of the screw feeder) B021 in the transfer mechanism B02, and a motor B032 that drives a rotor of a rotary valve B031 in the supply mechanism B03. The control unit B05 includes, as elements, a known motor driver that switches the operation of the motors B022 and B032 on and off and controls the rotation speed or output torque of the motors B022 and B032, and a microcomputer, programmable controller, general-purpose personal computer, workstation, or the like that commands the motor driver to realize the rotation speed or output torque of the motors B022 and B032. The motor driver rotates the motors B022 and B032 by sequentially applying current to the coils of each phase contained in the motors B022 and B032, and controls the rotation speed and output torque of the motors B022 and B032. Increasing the current and / or voltage applied to the coils of the motors B022 and B032 increases the output torque of the motors B022 and B032 and increases the rotation speed. Decreasing the current and / or voltage applied to the coils of the motors B022 and B032 reduces the output torque of the motors B022 and B032 and decreases the rotation speed. When controlling the motors B022 and B032, the magnitude of the current flowing through the coils may be increased or decreased using PWM (Pulse Width Modulation) control.

[0045] The control unit B05 of the constant-volume feeders B1, B2, and B3 of this embodiment basically uses a loss-in-weight method (integrated loss method) to perform feedback control (e.g., PID control) on the discharge flow rate per unit time of the powder discharged by the feeders B1, B2, and B3. Specifically, the weight of the powder lost from the hopper B01 by being sent out by the transfer mechanism B02 is constantly measured by a measuring device B04, and the progress of the weight decrease is compared to a preset target value for the discharge flow rate. The rotation speed and / or output torque of the motor B022 are increased or decreased in a direction that reduces the deviation between the two, thereby increasing or decreasing the discharge flow rate of the powder from the feeders B1, B2, and B3.

[0046] In addition, as already described, when the amount of powder in the hopper B01 falls to a predetermined lower limit, the control unit B05 activates the motor B032 that drives the rotor of the rotary valve B031 of the supply mechanism B03 to feed the powder stored in the supply mechanism B03 into the hopper B01. Then, when the amount of powder in the hopper B01 recovers to a predetermined upper limit, the control unit B05 stops the operation of the motor B032 to prevent any more powder from being fed into the hopper B01.

[0047] This embodiment is intended for the production of pharmaceutical tablets. In order to mass-produce high-quality tablets without any problems, it is extremely important to maintain the ratio of the active ingredient contained in the mixed powder supplied from the powder mixing and supplying system B to the molding machine A within a desired range. In short, the first priority is placed on the control of the constant-volume supply feeder B1, which stores and discharges the active ingredient.

[0048] The control unit B05 switches the control of the feeders B1, B2, and B3 depending on the difference between the discharge flow rate of the main agent measured via a measuring device B04 provided in the feeder B1 and its target value T. In this embodiment, as shown in FIG. 6, multiple stages of correction condition values ​​PH1, PH2, PL1, and PL2 and abnormality detection values ​​PH3 and PL3 are set above and below the target value T of the discharge flow rate of the main agent by the feeder B1. The correction condition value PH1 is greater than the target value T, the correction condition value PH2 is greater than the correction condition value PH1, and the abnormality detection value PH3 is even greater than the correction condition value PH2. The correction condition value PL1 is smaller than the target value T, the correction condition value PL2 is smaller than the correction condition value PL1, and the abnormality detection value PL3 is even smaller than the correction condition value PL2. The multi-stage correction condition values ​​PH1, PH2, PL1, PL2 and the abnormality detection values ​​PH3, PL3 may be calculated by adding or subtracting a predetermined amount to or from the target value T, or by multiplying the target value T by a predetermined ratio. For example, Correction condition value PH1 = target value T x 1.01 (target value T + 1%) Correction condition value PH2 = target value T x 1.03 (target value T + 3%) Abnormality detection value PH3 = target value T x 1.05 (target value T + 5%) Correction condition value PL1 = target value T x 0.99 (target value T -1%) Correction condition value PL2 = target value T x 0.97 (target value T -3%) Abnormality detection value PL3 = target value T x 0.95 (target value T -5%) One idea is to do so.

[0049] [I] When the actual measured value of the discharge flow rate of the main agent by feeder B1 is between the correction condition value PH1 and the correction condition value PL1, which sandwich the target value T: This means that the current discharge flow rate of the main drug is close to the target value T and is appropriately adjusted. Therefore, the control unit B05 does not need to increase or decrease the magnitude of the current and voltage applied to the coil of the motor B022 of the feeder B1 from the current values, and therefore may maintain the rotation speed and output torque of the motor B022 without increasing or decreasing them from the current values. At this time, control unit B05 executes feedback control as usual to converge the discharge flow rate of excipients, etc. by feeder B2 to its target value, and also executes feedback control to converge the discharge flow rate of lubricants, etc. by feeder B3 to its target value. The target values ​​of the discharge flow rate of powder by feeder B2 and the target values ​​of the discharge flow rate of powder by feeder B3 are each values ​​proportional to the target value T or the actual measured value of the discharge flow rate of powder by feeder B1, i.e., values ​​such that the ratio of each powder contained in the mixed powder obtained by mixing those powders (especially the ratio of the main drug in the mixed powder) falls within a desired range.

[0050] [II] When the actual measured value of the discharge flow rate of the main agent by the feeder B1 is between the correction condition value PH1 and the correction condition value PH2, or between the correction condition value PL1 and the correction condition value PL2: This means that the current discharge flow rate of the main drug is not near the target value T, but the deviation between the actual measured value and the target value T is not very large. Therefore, the control unit B05 executes feedback control to increase or decrease the rotation speed and / or output torque of the feeder B1 in a direction to reduce the deviation between the actual measured value of the discharge flow rate of the main drug and the target value T. If the actual measured value of the discharge flow rate of the main drug is between the correction condition value PH1 and the correction condition value PH2, the discharge flow rate of the main drug is greater than the target value T, so the current and / or voltage applied to the coil of the motor B022 of the feeder B1 is reduced to decrease the discharge flow rate from the feeder B1. If the actual measured value of the discharge flow rate of the main drug is between the correction condition value PL1 and the correction condition value PL2, the discharge flow rate of the main drug is smaller than the target value T, so the current and / or voltage applied to the coil of the motor B022 of the feeder B1 is increased to increase the discharge flow rate from the feeder B1. At this time, control unit B05 executes feedback control as usual to converge the discharge flow rate of excipients, etc. by feeder B2 to its target value, and also executes feedback control to converge the discharge flow rate of lubricants, etc. by feeder B3 to its target value. The target values ​​of the discharge flow rate of powder by feeder B2 and the target values ​​of the discharge flow rate of powder by feeder B3 are each values ​​proportional to the target value T of the discharge flow rate of powder by feeder B1 or the actual measured value, i.e., values ​​such that the ratio of each powder contained in the mixed powder obtained by mixing those powders falls within a desired range.

[0051] [III] When the actual measured value of the discharge flow rate of the main agent by the feeder B1 is between the correction condition value PH2 and the abnormality detection value PH3, or between the correction condition value PL2 and the abnormality detection value PL3: This means that the deviation between the actual measured value of the discharge flow rate of the main drug and the target value T has increased relatively significantly. The control unit B05 executes feedback control to increase or decrease the rotation speed and / or output torque of the feeder B1 in a direction to reduce the deviation between the actual measured value of the discharge flow rate of the main drug and the target value T. If the actual measured value of the discharge flow rate of the main drug is between the correction condition value PH2 and the abnormality detection value PH3, the discharge flow rate of the main drug is greater than the target value T. Therefore, to reduce the discharge flow rate from the feeder B1, the current and / or voltage applied to the coil of the motor B022 of the feeder B1 is reduced. In this case, the decrease per unit time of the applied current, applied voltage, rotation speed, or output torque, or the absolute value of the gain in the feedback control (proportional gain, integral gain, or differential gain in the case of PID control) is made larger than in the case of [II] above. In other words, compared to the case of [II] above, the discharge flow rate of the main drug from the feeder B1 is operated to approach the target value T more quickly. If the actual measured value of the discharge flow rate of the main drug falls between the correction condition value PL2 and the abnormality detection value PL3, the discharge flow rate of the main drug is smaller than the target value T, and therefore, in order to increase the discharge flow rate from feeder B1, the magnitude of the current and / or voltage applied to the coil of motor B022 of feeder B1 is increased. In this case, the increase per unit time of the applied current, applied voltage, rotation speed, or output torque, or the absolute value of the gain in feedback control, is made larger than in the case of [II] above. In other words, compared to the case of [II] above, the discharge flow rate of the main drug from feeder B1 is operated to approach the target value T more quickly. Also at this time, control unit B05 continues to execute feedback control as usual to converge the discharge flow rate of excipients, etc. by feeder B2 to its target value, and also executes feedback control to converge the discharge flow rate of lubricants, etc. by feeder B3 to its target value. The target values ​​of the discharge flow rate of powder by feeder B2 and the target values ​​of the discharge flow rate of powder by feeder B3 are each values ​​proportional to the target value T of the discharge flow rate of powder by feeder B1 or the actual measured value, i.e., values ​​such that the ratio of each powder contained in the mixed powder obtained by mixing those powders falls within a desired range.

[0052] [IV] When the actual measured value of the discharge flow rate of the main agent by the feeder B1 is greater than the abnormality detection value PH3 or less than the abnormality detection value PL3: This means that an abnormality has occurred in which the actual measured value of the discharge flow rate of the active ingredient completely deviates from its target value T. Therefore, feedback control of the discharge flow rate for feeder B1 alone may not be enough to keep the proportion of the active ingredient contained in the mixed powder to be supplied to molding machine A within an appropriate range. Therefore, control unit B05 increases or decreases the discharge flow rates of powders other than the active ingredient discharged from feeder B2 and / or feeder B3 other than feeder B1, thereby attempting to keep the proportion of the active ingredient contained in the mixed powder to be supplied to molding machine A within an appropriate range. If the actual measured value of the discharge flow rate of the active ingredient is greater than the abnormality detection value PH3, the flow rate of powders such as excipients discharged from feeder B2 is increased from normal, and / or the flow rate of powders such as lubricants discharged from feeder B3 is increased from normal. If the actual measured value of the discharge flow rate of the main drug is smaller than the abnormality detection value PL3, the flow rate of powder such as excipients discharged by feeder B2 is reduced from the normal rate, and / or the flow rate of powder such as lubricant discharged by feeder B3 is reduced from the normal rate. In this case, the discharge flow rate of powder by feeder B2 and / or feeder B3 deviates from the target value proportional to the target value T of the discharge flow rate of the main drug. The discharge flow rate of the main agent by the feeder B1 may be controlled in accordance with the above case [III]. In the case of [IV], the supply flow rate per unit time of the mixed powder, which is a mixture of the active ingredient, excipients, lubricants, etc., to the molding machine A will increase or decrease compared to the normal cases of [I], [II], or [III]. The control unit B05 may adjust the rotation speed of the turntable 3 and punches 5 and 6 of the molding machine A according to the supply flow rate. That is, if the supply flow rate of the mixed powder to the molding machine A increases compared to normal, the rotation speed of the turntable 3 and punches 5 and 6 is increased to increase the amount of mixed powder consumed per unit time in the molding machine A. Conversely, if the supply flow rate of the mixed powder to the molding machine A decreases compared to normal, the rotation speed of the turntable 3 and punches 5 and 6 is decreased to decrease the amount of mixed powder consumed per unit time in the molding machine A.

[0053] In this embodiment, there is provided a first powder supplying device B1 that stores and discharges a first powder (principal agent) and second powder supplying devices B2 and B3 that store and discharge a second powder (excipients, lubricants, etc. other than the principal agent), and the mixed powder obtained by mixing the first powder and the second powder discharged from both powder supplying devices B1, B2, and B3 at a required ratio is supplied to equipment A that performs processing in a subsequent process, and the flow rate of the first powder discharged by the first powder supplying device B1 and the flow rate of the second powder supplying device B2 and B3 are controlled by the flow rate of the first powder discharged by the first powder supplying device B1 and the flow rate of the second powder supplying device B2 and B3. The powder mixed supply system B is provided with a control unit B05 that controls the flow rates of the second powder discharged by the supply devices B2 and B3 so that they converge to their respective target values, and when the flow rate of the first powder discharged by the first powder supply device B1 deviates from its target value by a predetermined amount or more, the control unit B05 increases or decreases the flow rate of the second powder discharged by the second powder supply devices B2 and B3 so that the ratio of the first powder to the second powder contained in the mixed powder is maintained within a desired range.

[0054] According to this embodiment, even if the flow rate of the first powder discharged by the first powder supplying device B1 suddenly changes, the flow rate of the second powder discharged by the second powder supplying devices B2 and B3, which are different from the first powder supplying device B1, can be increased or decreased to control the ratio of the first powder to the second powder in the mixed powder supplied to the equipment A that performs the downstream processing so as not to deviate from a desired range. Therefore, it is possible to continue operating the molding machine A and the powder mixed supplying system B without issuing an alarm or outputting a signal indicating an abnormality.

[0055] The present invention is not limited to the above-described embodiment. In the above embodiment, as shown in Fig. 6, the control is changed depending on whether the discharge flow rate of the feeder B1 falls within a range defined by the abnormality detection value PH3, the correction condition value PH2, the correction condition value PH1, the target value T, the correction condition value PL1, the correction condition value PL2, and the correction condition value PL3.

[0056] However, the number of correction condition values ​​PH1 and PH2 set between the target value T and the abnormality detection value PH3 is not limited to two, and it goes without saying that the number of correction condition values ​​may be one, or three or more.

[0057] For example, if the correction condition values ​​set between the target value T and the abnormality detection values ​​PH3 and PL3 are unified, and the correction condition values ​​PH2 and PL2 are excluded, then: *If the actual measured value of the discharge flow rate of the main drug by feeder B1 falls between the target value T and the correction condition value PH1, or between the target value T and the correction condition value PL1, the same as the above embodiment [I]. *If the actual measured value of the main drug discharge flow rate by feeder B1 falls between the correction condition value PH1 and the abnormality detection value PH3, or between the correction condition value PL1 and the abnormality detection value PL3, the same as the above embodiment [II]. *If the actual measured value of the discharge flow rate of the main agent by the feeder B1 is greater than the abnormality detection value PH3 or smaller than the abnormality detection value PL3, the same as the above embodiment [IV]. This means that...

[0058] Alternatively, three correction condition values ​​are set between the target value T and the abnormality detection values ​​PH3 and PL3. If additional correction condition values ​​PH2' and PL2' are set between the correction condition values ​​PH2 and PL2 and the abnormality detection values ​​PH3 and PL3, then: *If the actual measured value of the discharge flow rate of the main agent by feeder B1 falls between the correction condition value PH2 and the correction condition value PH2', or between the correction condition value PL2 and the correction condition value PL2', the same as the above embodiment [III]. *When the actual measured value of the discharge flow rate of the main agent by the feeder B1 is between the correction condition value PH2' and the abnormality detection value PH3, or between the correction condition value PL2' and the abnormality detection value PH3, The control unit B05 executes feedback control to increase or decrease the rotation speed and / or output torque of the feeder B1 in a direction to reduce the deviation between the actual measured value of the discharge flow rate of the main agent and the target value T. Here, if the actual measured value of the discharge flow rate of the main agent is between the correction condition value PH2' and the abnormality detection value PH3, the magnitude of the current and / or voltage applied to the coil of the motor B022 of the feeder B1 is reduced to reduce the discharge flow rate from the feeder B1, but the amount of decrease per unit time of the applied current, applied voltage, rotation speed, or output torque, or the absolute value of the gain in the feedback control (proportional gain, integral gain, or differential gain in the case of PID control) is made larger than in the case of [III] above. On the other hand, if the actual measured value of the discharge flow rate of the main drug is between the correction condition value PL2' and the abnormality detection value PL3, the magnitude of the current and / or voltage applied to the coil of the motor B022 of feeder B1 is increased to increase the discharge flow rate from feeder B1, but the increase per unit time of the applied current, applied voltage, rotation speed, or output torque, or the absolute value of the gain in the feedback control is made larger than in the case of [III] above. Also, in this case, the control unit B05 executes feedback control as usual to converge the discharge flow rate of excipients, etc. by feeder B2 to their target values, and also executes feedback control to converge the discharge flow rate of lubricants, etc. by feeder B3 to their target values. *If the actual measured value of the discharge flow rate of the main agent by the feeder B1 is greater than the abnormality detection value PH3 or smaller than the abnormality detection value PL3, the same as the above embodiment [IV]. This means that...

[0059] In addition, the specific configuration of each part can be modified in various ways without departing from the spirit of the present invention. [Explanation of symbols]

[0060] A: Equipment for post-processing (powder compression molding machine) B...Powder mixing supply system B1...First powder supply device (quantitative supply feeder) B2, B3... Second powder supply device (quantitative supply feeder) B01…Hopper B02...Transport mechanism (screw feeder) B021...Transfer element (screw blade) B022...Motor B03…Supply mechanism B04...Measuring Instruments B05...Control unit

Claims

1. The device has a first powder supplying device that stores and discharges a main ingredient, and a second powder supplying device that stores and discharges powder other than the main ingredient, and supplies a mixed powder obtained by mixing the main ingredient and powder other than the main ingredient discharged from both powder supplying devices at a required ratio to a rotary powder compression molding machine that compresses the mixed powder to form tablets, each of the first powder supply device and the second powder supply device includes a hopper for storing powder, a transfer member for sending out the powder provided from the hopper so as to be discharged, a motor for driving the transfer member, and a measuring instrument for measuring the amount of powder sent out and discharged by the transfer member; The control unit Normally, the rotation speed of the motor of the first powder supply device or the current or voltage applied to the motor coil is controlled so that the flow rate of the main agent discharged by the first powder supply device converges to its target value, and the rotation speed of the motor of the second powder supply device or the current or voltage applied to the motor coil is controlled so that the flow rate of the powder other than the main agent discharged by the second powder supply device converges to its target value. For the discharge flow rate of the main agent, a correction condition value is set that is close to the target value but is not identical to the target value and deviates from the target value, and an abnormality detection value is set that is farther away from the target value than the correction condition value, When the flow rate of the main agent measured by the measuring instrument of the first powder supplying device is between its target value and the correction condition value, the rotation speed of the motor of the first powder supplying device or the current or voltage applied to the motor coil is maintained unchanged, while the rotation speed of the motor of the second powder supplying device or the current or voltage applied to the motor coil is controlled so that the discharge flow rate of the powder other than the main agent measured by the measuring instrument of the second powder supplying device converges to the target value under normal conditions; When the flow rate of the main agent measured by the measuring instrument of the first powder supplying device is between the correction condition value and the abnormality detection value, the rotation speed of the motor of the first powder supplying device or the current or voltage applied to the motor coil is adjusted so that the flow rate of the main agent falls between the target value and the correction condition value, while the rotation speed of the motor of the second powder supplying device or the current or voltage applied to the motor coil is controlled so that the discharge flow rate of the powder other than the main agent measured by the measuring instrument of the second powder supplying device converges to the target value under normal conditions; A powder mixing supply system in which, when the flow rate of the main agent measured by the measuring instrument of the first powder supply device is not between its target value and the abnormality detection value, the rotation speed of the motor of the second powder supply device or the current or voltage applied to the motor coil is adjusted so that the ratio of the main agent to the powder other than the main agent contained in the mixed powder is maintained within the desired range, thereby increasing or decreasing the discharge flow rate of the powder other than the main agent measured by the measuring instrument of the second powder supply device from the normal target value, and the rotation speed of the turntable of the rotary powder compression molding machine is adjusted according to the flow rate of the mixed powder supplied to the rotary powder compression molding machine.

2. The second powder supplying device includes a powder supplying device that stores and discharges an excipient, and a powder supplying device that stores and supplies a lubricant, 2. A powder mixing supply system as described in claim 1, wherein, when the flow rate of the main drug measured by the measuring instrument of the first powder supply device is not between its target value and the abnormality detection value, the discharge flow rate of the excipient measured by the measuring instrument of the second powder supply device is increased or decreased from its normal target value, or the discharge flow rate of the lubricant is increased or decreased from its normal target value, and the rotation speed of the turntable of the rotary powder compression molding machine is adjusted according to the flow rate of the mixed powder supplied to the rotary powder compression molding machine.

Images