RU70492U1 - DEVICE FOR WEIGHT DOSING OF BULK MATERIALS - Google Patents

Abstract

The technical solution relates to dosing before packaging bulk products. The proposed device for weight dosing contains a loading hopper equipped with a shutter, a vibratory tray with an adjustable gate and a weighing bucket located under the vibratory tray. The geometrical dimensions of the tray and the position of the shutter of the loading hopper are selected in such a way that when the tray slide is open, the material naturally flows into the weighing hopper (coarse weight gain), and when the shutter is closed, the material is accurately refilled into the weighing hopper. Thus, a high dosing rate is ensured by using the natural outflow of materials, and the flow of material remains controlled, which ensures the required accuracy.

Description

The invention relates to dosing before packing bulk materials.

A weight-metering device is known that contains a vibratory tray made with slits through the exit slit, scales for measuring the dose of the product, and valves for coarse and accurate dosing (USSR author's certificate No. 1756202, publ. 23.08.92)

The disadvantage of this device is the lack of accuracy of dose dialing at high device performance.

Closest to the claimed device is a device for packaging hardware in boxes, consisting of a loading hopper, a vibratory tray, mounted under it scales with sensors. The vibratory tray is divided into wide and narrow compartments with shutters for stopping the supply of the product (USSR copyright certificate No. 471249 publ. 05.25.75)

In the known device, when setting the tilt vibration tray and when the dampers are open, a weight dose close to the nominal dose (coarse weight) is poured into the weighing hopper, after which the vibratory tray is installed in a horizontal position, and the shutter shuts off the material from the wide compartment. To achieve the nominal weight, the product is supplied only from the narrow compartment of the vibratory tray, after which the shutter of the narrow compartment is closed.

The technical result obtained by the implementation of the proposed invention is the creation of a high-performance device, which, characterized by compactness and reduced energy intensity, ensures stable operation when dispensing bulk materials

The specified technical result is achieved in that in the device for the weight dosing of bulk materials containing a loading hopper equipped with a shutter, a vibratory tray with an adjustable gate and a weighing bucket located under the vibratory tray, an adjustable gate is located adjacent to the shutter, and the position of the shutter and the length of the tray are chosen so so that the distance from the shutter to the point of intersection of the slope of the material with the horizontal plane is equal to the distance from the shutter to the end of the tray.

In the inventive device, a high dosing rate is provided through the use of natural outflow of materials, and the material flow remains controlled, which allows to provide the required accuracy.

Comparative analysis with the prototype shows that the claimed solution differs in the design of the tray, the requirements for the size of the outlet and the length of the tray, the relative position of the gate and damper, which ensures that the solution meets the criterion of "Novelty"

The above set of well-known and distinctive features allows you to implement the previously indicated technical result, namely, to create a highly productive device for weight dosing, which has smaller dimensions, a simpler design and low power consumption in comparison with the prototype.

The essence of the invention lies in the fact that in a device using two-speed dosing, a high feed rate of the material is ensured through the use of natural outflow of material with a small inducing effect from the side of the vibrating tray. In this case, the power required from the vibratory tray to provide the necessary

material feed rates are less than without using the natural flow of material. Filling is carried out at a low material feed rate, which is carried out when the gate is lowered (the degree of overlapping of the product supply is regulated by the gate). Filling takes place when a thin layer of product is fed, limited by the position of the gate. The product is supplied by vibration of the tray.

The performance of the tray depends on the width of the tray, the height of the layer of feed material, the feed rate of the material and is described by the formula:

Q = 3600γBVh (t / h), where

B - tray width, m;

V is the average speed of the material on the tray, m / s;

h is the height of the layer of material in the tray, m;

γ is the bulk mass of the material, t / m ² .

In the inventive device, the height of the material at the output of the lot h is determined based on the required performance of the tray with a rough rash. The height of the material at the exit of the tray depends on the length of the tray, the position of the shutter on the hopper and the dynamic slope angle of the bulk material.

With the gate raised, the maximum height of the outlet from the hopper (flap position) is determined based on the need to ensure flow control. To ensure controllability of the flow, the length of the tray L and the height of the outlet H are related

L = H / tgβ

β is the static angle of repose of the granular material formed by the line of natural repose of the granular material with a horizontal plane. The value of this angle is determined by the properties of the bulk material

The controllability of the flow is also ensured by the fact that the adjustable gate is located close to the damper hopper. This arrangement of the gate eliminates the ingress of material between the shutter and the gate, and when the gate is raised, the amount of material in the tray is determined only by the position of the hopper shutter

Improving the performance of the claimed device is ensured by increasing the height of the layer of material in the tray, which is caused by the use of natural pouring material and the vibration effect of the tray. When vibrating the bulk material, the angle of repose decreases, and the thickness of the material layer at the end of the tray increases. In addition, vibration exposure causes the material to move along the tray at a speed V

V = kaωcosγ, where

k = k ₁ + k ₂ cosα. k ₁ and k ₂ coefficients depending on material properties

γ is the angle between the pulling force of the magnet and the feeder tray;

ω is the angular frequency, in 1 / sec;

α is the angle of inclination of the tray in degrees;

and - the amplitude of the oscillation, m

Since in the inventive device, the speed of movement of the material on the tray is determined by the natural outflow of the material and the vibration impact on the material, to obtain a performance equal to the productivity of the prototype, a smaller amplitude of oscillations is required. This leads to lower power consumption of the device and a decrease in the size of the magnet.

The inventive device is shown in Fig. 1. A device for weight dosing of bulk material contains a loading hopper pos. 1, equipped with a shutter pos. 2, an adjustable slide pos. 3, mounted on a vibrating tray pos. 4, under which is installed

weighing bucket pos.5 on load cells pos.6., connected to the control unit pos.7.

The device operates as follows. Dosing material is loaded into the feed hopper pos. 1. The loading hopper is equipped with a shutter pos.2. with the help of which the thickness of the material layer of the main part of the dose of material is established. When the vibrodrive is turned on, the material located on the tray pos. 4 enters the weighing bucket pos. 5, and the speed of movement of the material is determined by the natural outflow of material and the stimulating effect of the vibratory tray. At the moment of accumulation in the weighing bucket pos.5 of the main part of the weighed dose (~ 90% -95%), the gate pos.3 under the influence of the control signal of the control unit according to 7 is lowered and the feed of the dosed material is reduced. Topping up the material in the weighing hopper is carried out with the vibrating feeder operating, with constant monitoring by weighing until a specified dose is obtained.

The proposed technical solution allows to reduce the dimensions of the device and reduce power consumption at high speed and metering accuracy.

The device was tested in pilot industrial conditions, where its high reliability and efficiency were confirmed.

Sources of information taken into account during the examination

1. USSR author's certificate No. 1756202, published 23.08.92 g "Weighing device"

2. USSR author's certificate No. 471249 published May 25, 75 g “Device for packing hardware in a box”

Claims (1)

A device for the weight dosing of bulk materials containing a feed hopper equipped with a shutter, a vibratory tray with an adjustable gate and a weighing bucket located under the vibratory tray, characterized in that the adjustable gate is located close to the shutter, and the position of the shutter and the length of the tray are selected so that the distance from the shutter to the point of intersection of the slope of the material with the horizontal plane is equal to the distance from the shutter to the end of the tray.