FR2618355A1 - CONTINUOUS FEEDING DEVICE FOR PARTICLE MATERIALS - Google Patents

Abstract

Device for continuously feeding particulate materials at a constant rate or speed designed to avoid any aggregation of particles even when they are subject to aggregation, characterized in that it comprises: - a hopper 3 whose surface the bottom 3a is inclined at an angle greater than the rest angle of the material to be delivered; - A feed roller 1 provided on the side of an outlet orifice 5 of said hopper; - A control door 2 having a semi-circular section profile to form a passage 6 for the material with said feed roller 1; and in that said feed roller 1 has an outer periphery which is provided with a plurality of axial grooves 7 having a width and a depth sufficient to receive the particles of the lowest layer of a particulate material delivered to from said passage 6.

Description

26 18355

  This invention relates to a device for continuously feeding at constant speed or speed products and particulate materials which is optimized so as to deliver particles without disaggregating them even when said particles are provided.

  particles are easily prone to disintegration.

  In a system for the continuous feeding of particles at a desired and predetermined constant speed or flow, when the particles to be delivered are easily subject to disintegration, the use of a screw or a conveyor belt makes not only particle disaggregation possible but also makes it difficult to deliver the particles at a desired constant rate (or speed). Consequently, when the particles slip, they are subject to disaggregation, or else a speed error can occur and in this case it is not possible to obtain a constant precise feeding of particles

by unitary rzta-orn.

  The present holder already offers a device for supplying particulate materials meeting the objectives specified above, which comprises a hopper whose bottom surface is inclined at an angle greater than the rest angle of the material to be delivered, a feed roller provided on the side of the hopper outlet and which has a peripheral friction surface on which the material to be delivered rubs, a semicircular section control door to form a passage for the material with

  the feed roller and a weir arranged under the feed roller.

  This device described in the Japanese utility model published under the number 53-

6221 gives excellent results.

  However, in the feed device mentioned above, despite the fact that the material to be delivered is in the form of particles, the feed roller simply has an outer periphery with friction made rough. Therefore, although the material can be properly delivered by the friction forces, as long as the speed of the feed roller is low, when this speed increases, there is a sliding of the material, which causes a mismatch between the speed feed roller and the quantity of particulate products delivered. In addition, the particles which are discharged from the passage of the material during the rotation of the supply roller, slide on the external periphery of said roller and they fall when the supply roller reaches a certain angle of rotation. Consequently, the material to be delivered falls out of the way.

discontinuous along the weir.

  Finally, when the particles to be delivered have a comparatively large diameter and when they are easily subject to disintegration, the material to be delivered is subjected to disaggregation when the phenomenon of sliding in the passage provided for this material appears. The present invention proposes to provide a device for feeding particulate material which does not have the drawbacks of the device:

  mentioned above and capable of delivering particles without disaggregating them and d.

  continuously, in proportion to the speed of the feed roller, mom

  when these particles are easily subject to disintegration.

  As has been shown above, with a device for continuously feeding particulate materials at a constant flow rate, comprising a feed roller provided with grooves for the delivery of the particles without disintegration, even when these particles are easily capable at a disintegration, it is possible to deliver the particles at a constant rate even when the pressure of the material in the hopper decreases with the reduction of the quantity of material contained in the hopper. Likewise, the particles can be reliably delivered with a low possibility of disintegration.

  even when they are easily prone to disintegration.

  Furthermore, the speed of the feed roller and the quantity of material delivered are proportional and the particles which have passed through 1 passage intended for the exit of the delivered material, never slide along the external periphery of the feed roller so well. that there is no

  possibility of discontinuous feeding of particles.

  Consequently, the subject of this invention is a device for continuously feeding particles at a constant flow rate. comprising a feed roll provided with grooves for delivering the particles without disaggregating it, even when these particles are easily subject to 1 disaggregation, characterized in that it comprises: a hopper whose bottom surface is inclined at an angle greater than the angle of rest of the material to be delivered, a feed roller provided on one side of the discharge opening of the hopper and a control station having a profile with a semi-circular section so as to form a passage for the material with the feed roller, 1 feed roller having an external periphery provided with a plurality of axial grooves whose width and depth are sufficient to receive the particles of the lowest layer of the materials in

  particles delivered from the passage.

  The particulate materials contained in the hopper fall into the weir from said passage, during the rotation of the feed roller. In this case, when the opening of the control door is reduced to a minimum such that the vertical dimension of the passage is reduced so as to correspond substantially to the dimensions of the particles, the material crosses said passage in a lateral file. When the vertical dimension of the passage provided for the material is large, the particles pass through the passage in a plurality of layers located one above the other. At this instant, the particles of the lowest layer are received in the grooves formed on the outer periphery of the feed roller and they are delivered progressively with the rotation of the feed roller, Consequently, it does not produce any slippage of the material to be delivered regardless of the speed of rotation of the feed roller and this speed and the amount of particulate material delivered are proportional, so

  that the material can be reliably delivered to the last particle.

  Furthermore, even when the vertical dimension of the passage provided for the particles is minimized, the particles can be reliably delivered.

  without disaggregation, even when they are easily subject to disaggregation.

  When the feed roller is rotated to a certain angle, the particulate material falls into the slide. At this time, the material never slides along the outer periphery of the feed roller but it is transported in the grooves of said roller to a position which corresponds to a predetermined angle of rotation of the feed roller. As a result, the material can fall off and be delivered continuously. Other features and advantages of this invention will become apparent from

  the description given below with reference to the accompanying drawings which illustrate it

  - A preferred embodiment devoid of any limiting character. In the drawings: - Figure 1 is. a schematic elevational view showing the supply device according to the invention; - Figure 2 is a side elevational view in vertical section showing an essential part of this device; - Figure 3 is a side elevational view and-in section illustrating the essential part of the device according to the invention with a control door in the fully open state; - Figure 4 is a sectional view on a larger scale showing the relationship between the groove and the particle; - Figures 5 (Figures 5A and 5B) are curves which illustrate the relationship between the amount of material delivered and the speed of rotation of the feed roller of the device according to the present invention on the one hand and of a device according to the prior art on the other hand, FIG. 5A referring to the device according to the invention and FIG. 5B referring to

  device according to the prior art.

  We refer to the drawings and first of all to FIG. I which represents a

  continuous feed device for particulate materials according to the invention.

  The device comprises a hopper 3 comprising a bottom surface 3a inclined at an angle greater than the rest angle of the material to be delivered, a feed roller 1 placed on the side of the discharge orifice 5 of the hopper, a control door 2 having a semi-circular section profile is placed in the discharge orifice 5 so as to form a passage 6 for the material to be delivered with the feed roller 1, a slide or chute 4 being arranged according to the roll 1. It will be noted that this structure is similar to that

  described in Japanese utility model number 53-6221 mentioned above.

  Under these conditions, it is unnecessary to describe it in detail.

  In the device according to the invention having the structure illustrated by the drawing, the feed roller 1 has on its outer periphery a plurality of axial grooves 7 each having a width 1 and a depth S so that they can receive the particles 11 of the layer

  the lowest of the particulate material 10 delivered from passage 6.

  The width 1 and the depth S of the grooves 7 can vary depending on the material to be delivered. Preferably, the profile of the section

  of each groove 7 is semi-circular rather than angular.

  The arc-shaped surface 7a of the groove 7 allows easy rolling of the particles 11. Consequently, when the opening of the passage 6 is reduced to a minimum as shown in FIG. 2, the feed roller 1 rotates with the particles 11 which it has received and these particles are tilted without being transported in the passage 6 when their vertices touch the control door L. Consequently, the material 10 can be delivered with less risk of disintegration even when it is made up of particles which are easily subject to disintegration, Since the particles 11 of the material 10 are received in the grooves 7, there is no sliding of the material to be delivered regardless of the speed of the feed roller 1, and the material can be

  easily-delivered to the last particle.

  The measurement data were obtained in the manner mentioned below by using on the one hand the device according to the invention described above comprising a grooved feed roller and on the other hand a device according to the

prior art.

  Table 1 below shows the data obtained using the device

  according to the invention and table 2 the data relating to the prior device.

  FIG. 5A illustrates the data relating to the invention and FIG. 5B the

  data concerning the prior art.

  The data indicated in Tables 1 and 2 below were obtained when the material was in the form of pallets easily subject to

  a disintegration and the opening of the control door 2 being adjusted to 40%.

  In the tables: n designates the measurement time number x designates the measured value x designates the average measured value î designates the standard deviation and we have: ok -x) n and the precision in% Accuracy (%) = Lx 100 Table 1 (present invention) Feed roller speed-o 0.84 1.4 2.8 5.6 11.2 16.8 22.4 28 tation (rpm) emps (sec,) 60 60 60 60 30 30 30 30 Measuring time (n) _

  1,308.6 550.8 1,131 2,233 2,215 3,317 4,293 5,421

  2,302.1 549.0 1,133 2,245 2,233 3,313 4,283 5,361

  3,309.9 556.3 1,136 2,244 2,202 3,320 4,329 5,452

  4,303.7 550t4 1,135 2,259 2,223 3,321 4,290 5,376 307.5 544t5 1,134 2,241 2,216 3,315 4,312 5,447

  X. 306.4 550.2 1,133.8 2,244.4 2,217.8 3,317.2 4,301.4 5,411.4

  a 2.97 3.78 1.72 8.43 10.19 2.99 16.81 36.88 Accuracy (Z) 0197 0.69 0t15 0.38 0.46 0.09 0.39 0.68 Quantity delivered (kg / h) 18.4 33; 0 68.0 134.7 266.1 398.1 516.2 649.4 Po o Ud n

2618-355

  Table 2 (Prior Art) Speed of the feed roller. 83 17.65 26.5 35.3 tation (r! M) Time (sec.) 30. 30 30 30 Measurement time (n)

1 2195 4286 5876 6530

2 2222 4196 5844 6650

3 2222 4246 5852 6510

4 2186 4196 5842 6640

2174 4184 5904 6620

6 2198 4230 5908 6660

2199; 5 4223 5871 6602

  c: 17.64 35.42 27.12 59.28 Accuracy (Z) 0.80 0.84 0.46 0.89 Quantity delivered (kg / h) 263.94.506.76 704> 52,792.24 L ' examination, on the one hand, of the curves of FIGS. 5A and 5B and on the other hand of tables 1 and 2 above, shows that it is possible to obtain a command and a control, proportional to the quantity of material in particles delivered

  determined by roller speed 1.

2618 3 5 5

Claims (2)

  1- Device for the continuous supply of particulate materials at a constant flow rate or speed, designed to avoid any disaggregation of the particles even when they are subject to disaggregation, characterized in that it comprises: - a hopper (3 ) whose bottom surface (3a) is inclined at an angle greater than the rest angle of the material to be delivered; - a feed roller (1) provided on the side of an outlet orifice (5) of said hopper;   - a control door (2) having a semi-section profile   circular to form a passage (6) for the material with said feed roller (1); and in that said supply roller (1) has an outer periphery which is provided with a plurality of axial grooves (7) having a width (1) and a depth (S) sufficient to receive the particles of the layer 1a. lower (11) of particulate material (10)   issued from said passage (6).   2- Device according to claim 1, characterized in that said   splines (7) have a section profile of substantially semi-shaped circular.