JPS59138533A - Device for fluidizing solid granular substance - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a device for facilitating the outflow of solid particulates, particularly fibrous or irregularly shaped solid particulates, from a hopper. More particularly, the invention relates to an apparatus for causing solid particulates, particularly fibrous or irregularly shaped solid particulates, to exit a hopper at a substantially constant mass flow rate.

PRIOR ART Ejecting solid particulate feed from a popper is a common industrial operation. In a typical hopper system, a helical auger at the bottom of the hopper rotates to force feed material out of the hopper holes. Ideally, the rotational speed of this auger defines the flow rate of the feed material. A mechanical stirrer may be used to fluidize the granules above the auger. Ideally, the feed material is of homogeneous bulk density and exits the hopper at a constant mass flow rate. Achieving these ideal conditions is extremely difficult;
This is particularly difficult when the material is fibrous or irregularly shaped, such as wood flour or sawdust. These materials have a high angle of repose and tend to form a self-supporting stable arch above the agitator while the fluidized solid particulates in the auger section are ejected. Therefore, the mass flow rate through the auger decreases and eventually reaches zero. Alternatively, the arch collapses to form a vertical chimney in the granule, the walls of which become self-supporting, creating similar problems.

Various means are used to collapse these arches and chimneys. These means typically include stirring the hopper and/or the majority of the hopper contents. For example, a single vertical shaft may be disposed inside the popper and a plurality of horizontal rondes may be attached along the length of the shaft, or the entire device may be vibrated or rotated to prevent collection of feed material. Alternatively, an air bladder is placed inside the hopper and inflated to break up the bridges formed in the feed material. All of these means are generally undesirable because they require large amounts of energy to operate properly. Furthermore, in poppers where the auger speed is electronically controlled in response to mass flow rate, excessive agitation can disrupt the proper operation of the electronic system.

OBJECTS OF THE INVENTION It is therefore an object of the invention to facilitate the outflow of granular solids from a hopper, in particular of fibrous or irregularly shaped granular solids, with a substantially constant mass flow rate and with minimal energy consumption. The objective is to provide a device that facilitates outflow.

Other objects, advantages and novel features of the invention will become apparent from the following description.

<Configuration of the Invention> According to the present invention, a flexible whip is suspended from one end within the hopper above the auger. This whip is small. It depends from a rotary motor of the mold, and as the motor rotates, the free end of the whip follows a generally circular path within which the whip moves eccentrically and almost randomly. As the free end of the whip moves, the whip strikes the particles in the hopper and fluidizes the solid particles around the arches and chimneys that have begun to form in the hopper. This provides a substantially constant mass flow rate. - because only a very small amount of granular feed material is fluidized per run;
The invention consumes minimal energy. Such a small amount of energy will not destroy the auxiliary electronic systems working with the hopper system.

Preferred embodiments> Preferred embodiments of the present invention will be described below, but those skilled in the art will readily understand that there are other embodiments.

As used herein, the term "whip" refers to an elongated, flexible, elastic member capable of whip-like movement, such as Spring Wye V-, Rubber, Flexible Plus Deck. It can be made with etc.

Furthermore, the term "eccentric" gf2 is used to describe a path of motion that is generally circular but whose center is offset from a predetermined axis of rotation.

FIG. 1 is a partially cut away perspective view of a typical hopper system equipped with the apparatus of the present invention prior to loading solid particulate matter. The hopper 10 has an agitator m14 which rotates about a central rod 16 to fluidize the solid particulates above the A-gar 18. As the auger 18 rotates, particulate matter is discharged from the hopper 10 through the vibrator 19.

Figure 2 shows 6 of the small collar system along line 2-2 in Figure 1.
A cross-sectional view is shown. As shown, fibrous or irregularly shaped particulates 12 are filled above the stirrer 14 to form a self-supporting arch 20. It is clear that if such an arch 20 is formed, a regular flow of the solid particulates 12 into the agitator 14 is prevented. Arch 20 partially collapses to form chimney 22. If the collapse occurs suddenly, the mass flow rate from the auger will not be uniform. Following the formation of the chimney 22, non-uniform heavy masses of solid particles 12 will fall irregularly from the chimney 22 into the agitator 14, further disturbing the mass flow rate.

These problems can be solved by the present invention. A whip 30 is suspended from a rotating motor 32 above the agitator 14 in the hopper 10. Whip 30 may be connected to motor 32 via a rigid shaft 36. It is desirable to bend the shaft 36 slightly so that the whip 30 is tilted relative to the vertical. An anchor 34 can be attached to the whip 30 for the reasons described below. The choice of material for this anchor 34 is not very important. For example, if the whip 30 is made of spring wire, the anchor 34 can be made of a coil spring. Operation of motor 32 rotates shaft 36 at a rate of preferably 1 to 10 revolutions per second, thereby causing anchor 34 to follow a large, generally circular path. Whip 3 within this circular path
o and anchor 3/1 create an eccentric, almost random movement. This movement causes the whip 3o and the anchor 34 to strike the walls of the arch 20 and chimney 22, thereby fluidizing the struck solid particles 72 and causing the walls to collapse.

This allows the flow of solid particulates 12 to the agitator 14 and auger 18 to be at a substantially constant mass flow rate.

The operation of the device according to the invention is illustrated in FIGS. 3a to 3d. 3rd a
The figure does not show #30 when the motor 32 is not operating. The whip 3o hangs at an angle and is surrounded by solid particles 12. Figure 3b shows the movement of the device as the motor 32 first rotates. Shaft 36 remains stationary so that whip 30 follows a generally circular path.

It will be seen that when the whip 30 is initially surrounded by solid particles 12, the movement of the whip is significantly damped and only a small radius core of the solid particles 12 is fluidized. The fluidized core of the solid particulates reaches the agitator 14 and forms a vertical chimney 22. The bottom of the chimney at this time is located just above the anchor 34.

When the bottom level of the chimney is below the anchor 34, the damping effect of the solid particles on the whip 30 disappears, the amplitude of the whip movement increases and the whip 30 moves more eccentrically, FIG. 3C. Hit the wall of chimney 22 randomly as shown. Each time the whip 30 hits the chimney wall, a small amount of solid particulate matter is knocked off. The knocked-off solid particulates fall and damage the anchor 34 and the lower portion of the whip, thus momentarily weakening the movement of the whip 30, as shown in Figure 3d. It will be appreciated that Figures 3b and 3d depict substantially the same conditions. In this manner, whip 30 alternates between states of undamped, high amplitude movement and damped, relatively small amplitude movement. This self-sustaining cycle maintains a relatively constant level of solid particulates above agitator 14 and solids 21 above auger 18.
provides a substantially uniform bulk density and a substantially constant mass flow rate at constant auger speed.

<Effects of the Invention> Using the apparatus of the present invention at a constant auger speed, a test was conducted in which a -80 mesh pine wood powder sample was continuously flowed out for 1 minute, and as a result, the fluctuation rate was only 1%. Ta.

A similar test using a conventional apparatus using a similar pine flour sample showed a variation rate of 2%. The device of the invention therefore has the advantage of providing a substantially constant mass flow rate at constant auger speed. The apparatus of the present invention does not require the use of complex electronic systems for varying auger speed to vary mass flow. Another advantage of the present invention is that it requires minimal energy because only a small amount of solid particulate material needs to be fluidized at a time, rather than the entire hopper contents. A further advantage is that the device of the present invention has a relatively small physical impact on the hopper system and therefore does not adversely affect other associated electronic systems.

The embodiments described above are intended to illustrate the principle and practical application of the invention. Therefore, the present invention is not limited to the embodiments described above, but can be modified in many ways.

[Brief explanation of the drawing]

FIG. 1 is a partially cut away perspective view showing the apparatus of the present invention installed in a typical water tube system prior to containing solid particulate matter. FIG. 2 is a cross-sectional view taken along line 2--2 of FIG. 1, showing self-supporting arches and chimneys formed by solid particulates. Figures 3a to 3d are explanatory diagrams showing patterns of movement within the popper at position +a according to the present invention. 10...Hopper, 12...Solid particulate matter, 14...
・Agitator, 18...Auger, 20...Arch, 2
2...Chimney-130...Whip, 32...Rotating motor, 34...Anchor, 36...Shi1/ft. Patent Applicant United States Agent Yuki Omata 3
c 3d 3

Claims (1)

[Scope of Claims] A 1° flexible whip is placed vertically in the popper so that one end of the whip hangs freely above the hole in the hopper, and about a vertical axis in the hopper. The whip is coupled to means for imparting rotation to the whip so that the whip hits the solid particulate matter in the hopper, thereby fluidizing the solid particulate matter above the aperture of the hopper and removing it from the aperture of the hopper. Solid particulate fluidization device that facilitates the outflow of solid particulates. 2. The means for imparting rotation to the whip is a rotary motor;
2. Apparatus according to claim 1, wherein said motor imparts eccentric movement to said whip, generally in a circular path. 3. The rotary motor and the whip are connected through a substantially rigid shaft, and the whip is supported by the shaft at an angle with respect to the vertical.
Apparatus described in section. 4. The device of claim 3, wherein an anchor is attached to one freely depending end of the whip.