RU2799982C1 - Device for weight continuous metering of bulk materials - Google Patents

Abstract

FIELD: metering.

SUBSTANCE: invention is intended for weight continuous metering of bulk materials. The device comprises a batch dispenser (1), a loading tray (4), a vibrating tray (9), a control unit (17). The batch dispenser (1) is made in the form of a hopper mounted on a movable plate (2) having a measuring container and a drive (3). The loading tray (4) is mounted on the weighing device (5). Moreover, one edge of the loading tray (4) is fixed on the weighing device (5) using a hinge (6), and the other edge of the loading tray (4) is fixed on the weighing device (5) using a bracket (7). Under the loading tray (4) there is a drive (8) for turning the loading tray (4) relative to the hinge (6). The vibrating tray (9) is mounted on a movable platform (11) fixed with a hinge (13) on a fixed support (12). The fixed support (12) also has a vibrator (15) connected to the loading edge of the vibrating tray (9) and a drive (14) that ensures the rotation of the movable platform (11) around the hinge (13). A flow sensor (16) is installed under the pouring edge of the vibrating tray (9). The flow sensor (16) has a sensitive element in the form of a plate, onto which the flow of the dosed material falls from the pouring edge of the vibrating tray (9). The control unit (17) is connected by its inputs to the weighing device (5) and to the flow sensor (16), and its outputs are connected to the drive (3) of the batch dispenser, to the drive (8) for turning the loading tray, to the drive (14) of the vibrating tray and to the vibrator (15).

EFFECT: improved metering accuracy.

1 cl, 3 dwg, 2 tbl

Description

The device belongs to the field of continuous weight dosing of bulk materials and can be used in chemical, pharmaceutical and other industries.

A device for continuous weight dosing of bulk materials is known (RF Patent No. 2 251083, 27.04.2005, Bull. No. 12). The disadvantage of the device is that during vertical oscillations the bulk material expands uncontrollably, which reduces the dosing accuracy.

Closest to the proposed one is a device for continuous weight dosing - a prototype (RF patent No. 2 691 786, 18.06.2019, bull. No. 17), containing a batch dispenser of a volumetric principle of action, a loading tray, a base consisting of a fixed platform on which a movable platform is pivotally fixed with a drive for turning this platform relative to the hinge, a tray mounted on a movable support, a vibrator mounted on a fixed platform and connected with the loading edge of the tray, a weighing device, a control unit connected to a batch dispenser, a vibrator, a drive for turning the movable platform.

The disadvantage of the device is the low accuracy of dosing, since the determination of the weight of an individual portion is carried out at a time when the material is in motion, which causes dynamic effects on the weighing device and reduces the dosing accuracy.

The technical result of the claimed invention is to improve the accuracy of dosing.

The technical result according to the invention is achieved by the fact that in a device for two-stage continuous dosing of bulk materials, containing a batch dispenser in the form of a hopper mounted on a movable plate having a measuring container and a drive, a loading tray mounted on a weighing device, one end of the loading tray is fixed on the weighing device with a hinge, and the other edge of the loading tray is fixed on the weighing device with a bracket, under the loading tray a drive for turning the loading tray relative to the hinge is installed, a vibrating tray mounted on a movable platform, fixed by means of a hinge on a fixed support, on which a vibrator is also installed, connected to the loading edge of the vibrating tray, and a drive that ensures rotation of the movable platform around the hinge, a flow sensor installed under the pouring edge of the vibrating tray, having a sensing element in the form of a plate onto which the flow of dosed material falls from the pouring edge of the vibrators feeding tray, and a control unit connected by its inputs to the weighing device and to the flow sensor, and to the outputs - to the drive of the batch dispenser, to the drive of rotation of the loading tray, to the drive of the vibrating tray and to the vibrator.

The invention is illustrated by drawings, which show: in Fig. 1 device diagram; in fig. 2 is a fragment of the diagram of the device, at the time of unloading a separate portion from the portion dispenser into the loading tray; in fig. 3 is a fragment of the diagram of the device, at the time of unloading a separate portion from the loading tray into the vibrating tray.

The list of items indicated on the drawings: 1 - batch dispenser hopper; 2 - movable plate with a measuring container (hole); 3 - drive portion dispenser; 4 - loading tray; 5 - weight measuring device; 6 - hinge; 7 - bracket; 8 - loading tray drive; 9 - vibrating tray; 10 - bearing support; 11 - mobile platform; 12 - fixed platform; 13 - hinge; 14 - drive of the movable platform; 15 - vibrator; 16 - flow meter.

The device works as follows.

The material to be dosed is loaded into the hopper 1. The following data is entered into the control unit 17: the specified capacity of the dispenser Q g⋅s ^-1 ; bulk density of the dosed material, g/cm ³ ; approximate value ΔT ₀ s; the volume of the measuring container cm ³ . Based on these values, the control unit calculates the number of portions that must be fed into the loading tray 4 by the portion dispenser. After that, the dosing process begins. The material from the hopper 1 filled the measuring container in the movable plate 2. The control unit 17 calculates how many portions must be fed into the loading tray 4 and sends a control signal to the drive 3. By moving the movable plate 2 from the initial position (Fig. 1) to the unloading position (Fig. 2) to the left, as shown in Fig. 2. The portion is completely formed in the loading tray 4. The weighing device 5 weighs an individual portion and transmits information to the control unit 17, where the weight of the portion is determined. The control unit sends a signal to the drive 8, the tray 4 rotates relative to the hinge 6 (Fig. 3), and the portion is fed into the vibrating tray 9, in which the individual portions are converted into a continuous flow. The process of converting individual portions into a continuous flow in a vibrating tray is quite fully described in the works

After that, the loading tray 4 returns to its original position (Fig. 1). Particular attention should be paid to the fact that when weighing a portion, the material is at rest, i.e. the weighing device 5 is not affected by dynamic loads. In addition, while weighing a portion (Fig. 1), the drive 8 does not touch the loading tray 4. The control unit calculates the interval ΔТ=ΔP/Q, after which it is necessary to submit the next portion to the vibrating tray 9. This ends the first dosing cycle. The cycle consists of two stages. At the first stage, a separate portion is formed, which is fed into a vibrating tray. At the second stage, individual portions are converted into a continuous flow, this process has been studied in sufficient detail and the results have been published in the open press [Pershin, V.F. Two-stage continuous dosing in the production and use of carbon nanomaterials / V.F. Pershin, A.M. Vorobyov, V.M. Nechaev, A.A. Pasko, T.H.K. Alsayyad // Chemical and oil and gas engineering. - 2018. - No. 6. - S. 12 - 14, Alsayyad, T.H.K. Improvement of continuous weight dosing in the production and use of carbon nanomaterials / T.Kh.K. Alsayyad, V.F. Pershin, A.A. Baranov // Bulletin of the Tambov State Technical University. - 2018. - V. 24, No. 2. - S. 344 - 353]. During the implementation of the second dosing cycle, the second portion is formed by the batch dispenser, its weight is determined and it is fed into the vibrating tray after the time interval ΔT, which was calculated on the first cycle. It should also be noted that at each dosing cycle the condition of equal productivity of the dispenser to the specified value is strictly observed.

Before starting the dosing of a specific bulk material with a given capacity, it is advisable to experimentally determine the parameters of the doser, at which a continuous flow at the exit from the vibrating tray 9 in Fig. 1 is the most uniform. At the exit from the vibrating tray, the flow of material enters the sensitive element of the flowmeter 16, this method for determining the flow rate of bulk material and its uniformity is given in the description of utility model RU 87011. Information from the flowmeter is transmitted to the control unit 17, where the unevenness of the flow is calculated and control commands are generated for the drive of the movable platform 14 and the vibrator 15. By changing the angle of inclination of the vibrating tray and the frequency of vibration, the maximum uniformity of the material flow at the outlet shaping tray 9.

Comparison of the proposed device with the prototype was carried out in laboratory settings. When evaluating the dosing accuracy of the prototype, information was used from the description of the patent of the Russian Federation No. 2 691786, which states that at a productivity of 0.05 g/s, the error was 0.6% (example 1), and at a productivity of 0.5 g/s, the error was 0.15% (example 2).

In experimental studies using the proposed device, when dosing the same materials, at a productivity of 0.05 g/s, the error was 0.2%, and at a productivity of 0.5 g/s, the error was 0.05%.

In table. 1. the results of experimental studies using the proposed device with a given performance are given

Q=0.05 g⋅s-1

Table 1
The results of the experiment on continuous dosing at the productivity of the dispenser 0.05 g/s ΔP,g ΔT,s ΔP _SAMPLE ΔP _SAMPLE ,% 1 1.526 30.52 3.006 0.2 2 1.544 30.88 3 1.432 28.64 3.009 0.3 4 1.452 29.04 5 1.562 31.24 3.008 0.27 6 1.556 31.12 7 1.456 29.12 2.991 0.3 8 1.575 31.50 9 1.462 29.40 3.007 0.23 10 1.476 29.52 eleven 1.455 29.10 3.005 0.17 12 1.562 31.24 13 1.573 31.46 3.003 0.3 14 1.451 29.02 15 1.424 28.48 2,990 0.3 16 1.575 31.5 17 1.546 30.92 2.991 0.3 18 1.533 30.66 19 1.423 28.46 3.007 0.23 20 1.420 28.40 21 1.344 26.88 3.008 0.27 22 1.497 29.94 23 1.522 30.44 2.992 0.27 24 1.428 28.56 25 1.488 29.76 2.994 0.23 26 1.572 31.44 27 1.571 31.42 3.002 0.07 28 1.446 28.92 29 1.501 30.02 2.994 0.2 thirty 1.506 30.12

The dosed material is "Taunit M". The device worked in accordance with the regulations described above. Samples were taken from the flow of material pouring out of the unloading unit 8 during time intervals ΔT _SAMPLE equal to 60 s. The samples were weighed and in accordance with GOST 8.469-2002 according to the f-le:

where Q _Z - the specified value of productivity, kg / h; T is the actual time of sampling the control sample, min; G is the actual value of the mass of the control sample, kg; Q _max - the value of the maximum capacity limit of the dispenser, kg/h.

Processing the results of Table. 1 showed that the average dosing error is 0.2%. For the prototype, the dosing error under similar conditions was 0.6% (example 1 from the description of the patent of the Russian Federation No. 2691786).

Similarly, the dosing error was determined at a performance of Q=0.5 g⋅s ^-1 . The results of the experiments are given in table. 2. In this case, the specified sample weight is 6 g.

table 2
The results of the experiment on continuous dosing at the productivity of the dispenser 0.5 g/s ΔP,g ΔT,s ΔP _SAMPLE ΔP _SAMPLE ,% 1 15.072 30.14 30.024 0.08 2 15.441 30.88 3 14.692 29.38 29.976 0.08 4 14.752 29.50 5 14.862 29.72 30.011 0.04 6 15.398 30.80 7 15.496 30.99 29.971 0.10 8 14.757 29.51 9 14.962 29.92 30.024 0.08 10 14.676 29.35 eleven 15.255 30.51 30.010 0.03 12 15.162 30.32 13 15.273 30.55 30.016 0.05 14 14.922 29.84 15 14.724 29.45 29.976 0.08 16 14.875 29.75 17 14,546 29.09 29.979 0.08 18 14.833 29.67 19 14.856 29.71 30.020 0.07 20 14,870 29.74 21 15.644 31.29 30.030 0.1 22 15.174 30.35 23 15.122 30.24 29.975 0.08 24 14.728 29.46 25 14.888 29.78 29.976 0.08 26 14.872 29.74 27 15.571 31.14 30.026 0.09 28 14.881 29.76 29 14.692 29.38 29.964 0.12 thirty 15.306 30.61

Processing the results of Table. 2 showed that the average dosing error is 0.08%. For the prototype, the dosing error under similar conditions was 0.25% (example 2 from the description of the patent of the Russian Federation No. 2691786).

Thus, the goal is achieved, the accuracy of continuous dosing is increased three times.

Claims (1)

A device for two-stage continuous dosing of bulk materials, containing a batch dispenser in the form of a hopper mounted on a movable plate having a measuring container and a drive, a loading tray mounted on a weighing device, with one edge of the loading tray fixed to the weighing device with a hinge, and the other edge of the loading tray fixed on the weighing device using a bracket, a drive for turning the loading tray is installed under the loading tray relative to the hinge, a vibrating tray mounted on a movable platform, fixed by means of a hinge on a fixed support, on which a vibrator is also installed, connected to the loading edge of the vibrating tray, and a drive that ensures rotation of the movable platform around the hinge, a flow sensor installed under the pouring edge of the vibrating tray, having a sensing element in the form of a plate, on which the flow of the dosed material falls from the pouring edge of the vibrating tray, and a control unit connected with its inputs with a weighing device and with a flow sensor, and outputs - with a batch doser drive, with a loading tray rotation drive, with a vibrating tray drive and with a vibrator.