JPS63274441A - Powder weighing and mixing apparatus - Google Patents

Abstract

PURPOSE:To perform the weighing and mixing of a powder always with high accuracy, by respectively providing flow speed controllers to a plurality of supply containers and providing a powder amount detector on the side of a receiving container to control the flow speed controllers on the basis of a detected actually weighed value and a weighing set value. CONSTITUTION:The indication of a storage hopper becoming a mixing object, weighing order, a mixing condition or the like are indicated to a weighing control apparatus 17 and a weighing set value is subsequently set. When weighing start is indicated, for example, the screw feeder 12 of a storage hopper 1 selected by a change-over apparatus 19 is rotate in the set number of rotations to transfer a powder to a weighing hopper 14. The load cell 15 of the weighing hopper 14 detects the wt. of the transferred powder and the value thereof is fed back to a weighing control part. In the weighing control part, the deviation between an actual wt. value and the set value is calculated and the proper number of rotations are indicated to the screw feeder 12 at the next control cycle. In the same way, the amount of the powder from each storage hopper is subjected to weighing control.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a powder measuring and mixing device that manufactures new materials by weighing and mixing various types of powder.

(Prior art) Conventionally, as a measuring device applied to a powder measuring and mixing device,
In order to achieve highly accurate metering, a metering device with a limited flow rate is used instead of one with a variable flow rate.

Furthermore, in conventional powder measuring and mixing apparatuses, when powder is supplied from a plurality of supply containers to one container, a measuring device is provided attached to each supply container.

For example, when using a gravimetric method, two weighing devices are used for two powders, and a two-loop control function is used to predict and control the amount of inflow, as shown in Figure 5. JP-A-56-148019 and JP-A-56-1554
Publication No. 12 states that the average flow rate is calculated from the total discharge weight of the object to be measured and the required time in a predetermined number of past measurement cycles,
A control method is disclosed in which the deviation from the set measurement value is determined based on this average flow rate, and the flow rate or predetermined time in the next metering cycle is adjusted.

That is, the powder flow, t, is the remaining amount of powder in the supply container,
Since the values differ depending on the measurement setting value, powder physical property value, etc., highly accurate measurement cannot be expected with the same control function.

In addition, in order to achieve highly accurate measurement, we have installed a device that has the function of switching the flow rate between two types of fixed conditions, and a method of switching at a predetermined measurement deviation (Japanese Patent Laid-Open No. 57-72015
However, even in this case, two-loose control is required as a control function.

Here, we are using the expression 2-loop control capability; for example, if a distributed control device is used, metering can be processed within one control device; This is because it cannot be said that each is necessary. However, when considering the number of input/output points and software, it can be said that there are two control devices.

(Problems to be Solved by the Invention) Conventional liquid metering and mixing devices have the following drawbacks because the metering control is based on a constant flow rate.

■Measuring accuracy: Accuracy may not be guaranteed due to fluctuations in flow velocity due to disturbances or changes in powder physical properties.

Particularly in the case of hygroscopic powders or powders that tend to cause bridging, the fluidity of the powders differs depending on the storage environment conditions. Therefore, in a system that is used while being stored in a supply container, changes in environmental conditions (e.g., vibrations due to temperature, humidity, ancillary equipment for promoting powder fluidity, such as vibrators, air knockers, etc.) The fluidity of the powder changes. For this reason, the flow velocity conditions differ and the measurement accuracy deteriorates. As a countermeasure, it is necessary to limit the storage amount and the installation environment conditions of the device in order to maintain measurement accuracy, which results in increased initial cost and running cost of equipment.

■Measuring range: The measuring range is narrow.

The reason for this is that even if the metering is stopped, the inflow will still be visible due to the response delay of the system, and this flow rate is determined by the flow velocity. Quantity is guaranteed. Therefore, even if the same powder is to be weighed, weighing devices each having an appropriate measuring range are required, which increases the number of devices.

■Measuring time 2.Measuring time is affected by the measurement setting value.

If the metering setting value is small, the metering time will be short; if it is large, the metering time will be long. Therefore, a measuring device suitable for the manufacturing cycle is required depending on the measured value, and the number of devices increases.

In addition, for the reasons mentioned above, conventional powder measuring and mixing equipment requires a large number of independently controlled measuring devices to be installed for each supply container, and also for each optimal measuring time due to manufacturing capacity limitations. 1, a large number of weighing devices were installed, complicating the system.

The object of the present invention was achieved based on the above circumstances, and
A weighing control device that achieves high-precision weighing that is unaffected by flow velocity fluctuations due to disturbances or changes in powder physical properties, secures a wide weighing range, and realizes short-time weighing without being affected by the size of the weighing set value. By using this, we can configure the system, simplify the equipment, increase the manufacturing capacity,
In order to reduce raw material loss, ■ Initial cost reduction by reducing the number of equipment ■ Reducing maintenance man-hours by reducing the number of equipment ■ Reducing failures by improving reliability by reducing the number of equipment ■ Economic effect of reducing running costs by reducing raw material loss It is an object of the present invention to provide a powder metering and mixing device with high performance.

(Means for Solving the Problems) The above object of the present invention is to apply a metering control device that changes the flow rate from time to time by closed loop control when measuring powder to be measured, and to 1. This is achieved by using a powder measuring and mixing device that can reduce the number of equipment. Therefore, the powder measuring and mixing device of the present invention is configured by the following components.

1) Supply container: A container that stores the powder to be measured.

The capacity of the container requires a scale suitable for manufacturing.

In the present invention, there is no limit to the amount remaining in the container, and theoretically the amount remaining in the container is not limited.
Can measure up to o. Also, the physical properties of the powder (e.g. granularity, etc.)
! /C Any powder can be measured with the remaining amount Of as long as it has physical property values that allow it to flow out without being affected.

2) Flow rate control device: It has a number of flow rate control devices corresponding to the number of supply containers. For example, in a screw feeder, the flow is controlled by commanding the rotation speed.

A damper is a flow velocity control device that changes the flow by changing the opening degree.

As a drive, there is an ACC thermomotor, etc., for example. 3) Switching device Wt: A device for controlling a plurality of flow rate controllers with one drive control device. Although it is not necessary if the flow rate control device includes a drive control device, it may be installed to reduce costs.

4) Metering control device: Closed-loop precision metering control that changes the flow rate, and each powder is weighed with one metering device.

It is possible to measure a plurality of powders in the same container using one measuring device 1ilC, and the number of devices to be used can be reduced.

5) Pollination container: A container with a capacity suitable for the manufacturing scale.

Mixable powders are measured by cumulative metering.The basic components of the present invention are as described above, but there are various types of flow rate controllers that vary the flow rate.

There are screw feeders and rotary types that vary the flow by commanding the rotation speed, and if the powder has good fluidity, there are feeders that change the flow by varying the opening by position commands using the opening tank. be. Additionally, there are shutter darts and the like that stop the flow.

(Embodiment) Embodiments of the present invention will be described below with reference to the drawings.

One embodiment of FIG. 1 is Nf1! This figure shows a metering and mixing device for powders. That is, in this embodiment, raw materials are filled into N storage hoppers I4 as supply containers arranged on the upstream side, and powder is poured into a metering water tank as one pollination container arranged on the downstream side from this hopper. A case will be described in which the powder is fed and the electrolytic corrosion of the N type powder is cumulatively measured, and then the powder is transferred to a preparation tank for preparation.

Storage cylinders 1, 2, -, N are connected to motors 11, 21, .・-, screw feeder driven by NIK 12.22. -, via N2.

The exits are shutter gates 13, 23. - and N3, and the respective dart outputs are guided to the weighing hopper 14 by piping.

A load cell 15 as a detector is arranged in the measuring water horn 14 in order to measure the weight of powder transferred from each storage tank. The load cell 15 is connected to a weighing control device fjt17 through a load cell amplifier 16, and the weighing control device 17 is connected to a switching device 19 via a serge driver 18.

The switching device 19 switches 9 based on a command from the metering control device 17 to select one of the powder supply systems, and
It is provided so that opening/closing commands from the metering control device to the corresponding shutter darts and drive commands from the driver 18 are transmitted to predetermined motors.

In addition, the weighing hopper #14 is connected to the preparation tank 50 via the discharge f-), and is equipped with incidental equipment such as a pibrator and air knocker in order to eliminate powder remaining in the weighing hopper. The preparation tank 50 is a stirrer 51
, and is equipped with a bottom valve 52 at the outlet.

Next, the powder measuring and mixing process of the powder measuring and mixing apparatus configured as described above will be explained with reference to the control block diagram shown in FIG. 2.

First, the metering control unit 17a in the metering control device 17 specifies the storage hopper to be mixed, the total of the target storage hopper,
Measurement and mixing conditions such as tJlj order are specified.

When the metering setting value is set in the metering control device 17 and the start of metering is instructed, the supply system selected by the switching device 19, here the shutter gate 13 of the storage hopper fl, is first
When the screw feeder 12 is opened, a rotation speed command is transmitted from the drive control unit 17b of the metering control device 17 to the serve driver 18 so that the screw feeder 12 transfers the powder at a predetermined rotation speed, and the serve motor 11 to rotate the screw feeder to the specified rotation speed and cause the raw material to flow. As a result, the raw material in storage hopper 41 begins to be transferred to weighing hopper #14.

The load cell 15Fi of the weighing unit detects the weight of the transferred raw material, and feeds back the value to the weighing control unit 17m through the load cell amplifier 16.

The weighing control unit 17a calculates the deviation from the set value and the time change amount of the deviation from the fed-back actual weight value,
Based on the control methods of fuzzy control, optimal control, and learning control, the opening command (position command) that provides the next appropriate flow velocity is calculated. Then, in the next control cycle, the drive control unit 17b instructs the screw feeder with an appropriate rotational speed command to change the flow velocity.

As described above, the rotation speed of the screw feeder is controlled in a closed loop at a predetermined control period based on the observed amount of the 10-dossel 15, and as a result, the flow velocity is controlled.

When the metering deviation becomes small, the rotation speed of the screw feeder 12 becomes small and the flow velocity becomes very small.

When the amount of time change in the weighing deviation and the weighing deviation time becomes smaller and the weighing deviation becomes less than a certain value, the weighing is stopped, the shutter gate 13 is closed, and the rotation speed of the screw feeder 12 is 0), and the rotation is stopped. .

At this time, the flow velocity is minute and the amount of inflow is minute. Therefore, the operation of the screw feeder changes depending on the small recess system for the inflow amount after the metering is stopped, and the same metering device can measure the amount regardless of the size of the metering setting value, expanding the metering range. However, it is within the static accuracy of the detection end.

Also, the operating pattern of the shutter gate changes during the metering time, and regardless of the magnitude of the metering setting value, almost the same short-time metering can be performed.

Next, the process switches to measuring the flour in hopper 2, which was also selected. The switching device 19 is connected to the screw feeder 22 on the hopper 2 side.
Switch to. The measurement setting value is set in advance, and the same control as above is performed in accordance with the measurement start command to perform measurement. That is, the control functions within the control device are the same, and only the output signals to the screw feeder 22 and shutter gate 23 at the operating end are switched by the switching device 19.

When the cumulative weighing of a plurality of types of powder is completed by the weighing hopper 14, the discharge dart of the weighing hopper 14 is opened and the powder is introduced into the preparation tank 50. In addition, when discharging from the weighing hopper, the entire amount is discharged from K, which is ancillary equipment such as a pipe lake. In the preparation tank 50, a predetermined chemical solution is added and one stirrer 51 is driven to perform mixing. At the end of stirring, the bottom valve 52 opens and the mixed powder is discharged.

Next, the results of experiments conducted based on the present invention will be described.

This experiment was conducted using the measuring device shown in FIG. 1, which had 42 storage containers and no preparation tank.

The resulting weighing device can weigh up to 501C9, and the accuracy of the load cell is 1/2500. The rotation speed of the screw feeder is controlled by an inverter motor, and a rotation speed command (voltage output) is output from the metering control device.

Figure 6 shows the inverter input voltage (
This shows the flow rate (average value) characteristics relative to rotation speed). To describe the characteristics of these two types of powder, Powder A is in the form of granules and has an apparent specific gravity of approximately 0.5, while Powder B is a highly adhesive wheat flour with an apparent appearance. has a specific gravity of about 0.5. These two types of powder were sequentially measured using the configuration shown in Figure 1 without changing the control system or the like. In other words,
Powder A in the storage hopper 1 and powder B in the storage hopper 42 were sequentially weighed by switching the switching device 19 using the same control device.

FIG. 7 shows the result of weighing 1 kg of powder A at that time.

Furthermore, Fig. 8 shows the results of weighing 1 kg of powder B.

As is clear from FIGS. 7 and 8, highly accurate weighing results were obtained with approximately the same weighing time, although the operation pattern of the screw feeder rotation speed was different.

In addition, changes were made to the flow characteristics by applying vibration to the storage bowl to compress the powder and change the fluidity. Although the number of turns of the screw feeder's operation is different, both the metering time and metering accuracy were improved. I got the same results.

Table 1 shows the relationship between measurement time and measurement accuracy with respect to measurement settings. Note that the measurement accuracy was determined by measuring the flowed powder using a different certified weighing scale.

When weighing 5 kg, the weighing time was longer due to the limit on the maximum rotation speed of the inverter motor used in this experimental system, but the weighing accuracy was ±29-. By increasing the capacity of this inverter motor, the measuring time can be shortened.

FIG. 9 shows the results of weighing 5 kg of powder B. As is clear from this, it flows out at the maximum rotation speed, and if this flow rate is increased, the time will be further shortened.

Table 1 Also, in this experimental system, a load cell with an accuracy of 1/2500 was used, so in the case of 501F measurement, the accuracy was ±2, which is equal to the static load accuracy of the load cell. Therefore, it can be seen that if a 1/5000 type is used as a load cell, an accuracy of ±1.0 inch can be obtained at a weighing lens l:100. Furthermore, in this experimental system, an inverter motor was used, and the rotation speed range (ratio of minimum rotation speed to maximum rotation speed) was 1:10. If this motor is replaced with a rotary motor, the range of revolutions will be widened, and high-accuracy measurement will be possible with the same measuring time at 1:100.

In the embodiment described above, the case is described in which N types of powder are cumulatively weighed in one weighing hopper, and the number of paddy types to be weighed is not limited. However, in view of the system, the optimum number of screw feeders to be controlled by the same metering device is about 8 side diameters.

FIG. 3 shows a modification of the invention.

In this modified example, a detector is installed in the pollination container described in the previous embodiment to measure the amount of powder, and a detector is installed in the supply container to measure the amount of powder flowing out. It combines the subtraction weighing method.

That is, in the figure, it has the same configuration as the embodiment of the 1st to N-1th storage hollow/matter, its powder supply system, and measuring/mixing system cutting tip, so the same reference numerals will be used and the explanation will be omitted. In this example, a storage hopper N is installed on a load cell N5, and the amount of powder flowing out of the hopper N is measured. Also,
An opening degree DAN 4N6 is provided at the outlet of the hole INH, and the outflow element is controlled by the opening degree of DAN NO 4. In addition,
In the figure, the opening degree is shown as the operation end for subtraction metering, but it is also possible for other screw feeders and the like.

FIG. 4 shows a control block diagram of the above modification.

In other words, regarding the storage hole INN, when the outflow amount of the powder filled in the storage hole I-NK is subtracted and measured by the load cell N5 and transferred to the 1-measurement hot spring 14, the powder that has been filled in the storage hole I-NK is transferred to the storage hole INN which has already been transferred. z month, 2.・ , N
-1 powder is cumulatively weighed. The actual measurement values obtained by the subtraction measurement method and the cumulative measurement method in this way are fed back to the corresponding subtraction method measurement control section 17a'' and addition method measurement control section 171', respectively.

Each of the metering control units 17 a' and 17 a'' calculates the deviation and deviation time change amount between the set value and the set value, and adjusts the rotation speed of the screw feeder based on fuzzy control, learning control, or optimal control. and position command converter 1
The opening degree of the opening damper N6 converted by 7C is transmitted to the drive control section 17b, and is switched and outputted by the switching device 19.

With the above configuration, for example, by performing minute measurements using subtraction weighing and weighing items with large measurement settings using additive weighing, it is possible to perform measurements over a wider measurement range.

Further, as a modification of the present invention, the preparation tank can be provided in a mobile manner. By configuring it in this way, for example, stirring can be performed.

By moving a plurality of types of chemical liquids supplied to the preparation tank during the reaction under the corresponding discharge yt, the preparation tank can simplify the piping system and receive only the desired liquid.

In the embodiment shown in FIG. 1, a load cell was used as an example of the detection device, but other detectors may also be used. For example, there are various level meters. Here, the measurement range varies depending on the static accuracy of the detector.

(Effects of the Invention) As described above, according to the powder measuring and mixing device of the present invention, by adopting a measuring device that is not affected by measurement settings, residual powder amount, powder properties, etc., ■ Reduction in the number of measuring devices ■ Raw materials Since the loss can be reduced, the following economic effects can be obtained.

■Initial cost reduction by reducing the number of devices ■Reducing maintenance man-hours by reducing the number of devices ■Reducing failures by improving reliability by reducing the number of devices ■Remaining raw materials due to flow rate control! (Head difference), etc., and running costs are reduced by reducing raw material loss.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a measuring and mixing device for multi-ply powder according to an embodiment of the present invention, FIG. 2 is a control block diagram explaining the device shown in FIG. 1, and FIG. 3 is a measuring and mixing device according to a modification of the present invention. The configuration diagram of the device, Figure 4 is a control block diagram explaining the device shown in Figure 3, Figure 5 is a diagram explaining the conventional device, Figure 6 is a flow rate characteristic diagram of two types of powder using a screw feeder, and Figure 7 is a diagram explaining the device. 9 to 9 are metrological characteristic diagrams based on experimental results conducted based on the present invention. 1.2. -, N-storage hot springs 9.11, 12.・-9N
l・-Sir? Motor, '12, 22, --, N 2
-・Screw feeder, 13, 23.・-, N3・・
・Shutter gate, 14・-Measuring hotspot, 15. N5・
・・Load cell, 16・−Load cell amplifier, 17・・
- Metering control device, 18 - sir is driver, 19...
Switching device, N6-opening Danno, 50-adjustment tank, 5
1 - stirrer, 52 - bottom valve. Figure 5 Figure 6 0s9fA≧zu (Same 7I (V) Procedural Amendment 1 Temple 8 PM Office E==Cho 1° Showa 6
July 7, 2015 1, Indication of Matter A'1 Patent Application No. 106415 of 1986 2, Name of the invention Powder Measuring and Mixing Apparatus 3, Relationship with the person making the amendment 1'↑: Name of patent applicant : (520) Fuji Photo Film Co., Ltd. 4, Agent address: 100 Chiyo, Tokyo [3-2-5 Kasumigaseki, U-ku, Kasumigaseki Building, 29th floor, Kasumigaseki Pill, Post Office Private Store Box No. 4
No. 9 Sakae) Goi 1 Temple 8pm Office Phone: (581)-9GO1 (Representative) (1) Specification page 4, line 20, "Liquid measuring and mixing device"
is corrected as "powder meter a mixing device". (2) Paperback page 13, line 15, “Shirt tag game-1~”
is corrected as "screw feeder". (3) On page 14, line 20 of the same book, r5ONfJ is corrected to "5 nibi." (4) On page 15, line 9 of pronunciation, ``flour body'' is corrected to ``1 flour-like''.

Claims (1)

[Claims] 1) A powder measuring and mixing device that weighs and mixes multiple types of powder using a closed-loop powder measuring method that changes the flow rate, which comprises at least two or more supply containers. and,
a pollination container that measures the powder sent from each supply container; a flow rate controller that is attached to each of the supply containers and that controls the flow rate; a detector that is attached to the pollination container that measures the amount of powder; A metering control device that calculates a flow rate control amount based on an actual measured value measured by a meter and a metering setting value, and a switching device that switches and outputs the flow rate control amount to the flow rate controller, respectively. Characteristic powder measuring and mixing device. 2) The metering control device calculates the flow rate control amount by fuzzy control, learning control, or optimal control from the deviation between the arbitrarily set metering setting value and the actual metering value and the deviation time change amount. The powder measuring and mixing device according to scope 1. 3) The powder measuring and mixing device according to claim 1, wherein the flow rate controller is provided by a screw feeder, an opening damper, or a rotary device. 4) A claim characterized by combining an addition measurement method in which a detector is installed in a pollination container for measurement, and a subtraction measurement method in which a detector is installed in a supply container to measure the amount of powder flowing out. The powder measuring and mixing device according to item 1. 5) The powder measuring and mixing apparatus according to claim 1, wherein each powder measured in a pollination container is transferred to a preparation tank and mixed. 6) The powder measuring and mixing device according to claim 1, wherein the powder transferred from the supply container is cumulatively weighed in the pollination container and then transferred to the preparation tank.