WO2015135751A1

WO2015135751A1 - Screening machine for sizing material to be screened, in particular tumbler screening machine

Info

Publication number: WO2015135751A1
Application number: PCT/EP2015/053882
Authority: WO
Inventors: Klaus Hardt; Wubo Tian
Original assignee: Allgaier Werke Gmbh
Priority date: 2014-03-12
Filing date: 2015-02-25
Publication date: 2015-09-17
Also published as: DE102014204595B3; DE202014007220U1

Abstract

A screening machine for sizing bulk material comprises the following features: • - a housing (3) having a base (3.1), a cover (3.2) and a peripheral wall (3.3); • - a sizing screen (4) which divides the peripheral wall into an upper and a lower wall part; • - a first active vibration exciter (5) which acts upon the housing; and • - a second active vibration exciter (50) which indirectly or directly acts upon the sizing screen (4).

Description

Sieving machine for classifying screenings, in particular tumble screening machine

The invention relates to a screening machine for classifying screenings. Such screening machines can as Taumelsiebmaschinen or as

Vibration sieve be designed. See US 8,485,364 B2.

Machines of this type are used in many industries, such as the food industry, the chipboard industry or the chemical industry. The machines serve to separate a flowable material, such as a suspension, or a pourable material as a debris into individual components. A possible purpose of such a device is, for example, to dissect a granular material into different fractions of different particle sizes. Another

Application is the removal of impurities from a screenings. In the screened material retained by a sieve, this is referred to as the residue, and the material passing through the sieve is referred to as the passage.

A screening machine of the type mentioned comprises a housing, further a

Screen construction with at least one screen, an inlet for the screenings and at least one outlet for the residue and at least one outlet for the passage of the screenings.

If a screenings are to be divided into two or more fractions, so you need this purpose a corresponding number of sieves in the sieve structure. Each sieve is also called sieve deck. These screening decks are generally arranged one above the other. The screenings are first placed on the upper deck via the inlet. During the sorting or

Klassiervorgangs creates a first fraction, by a first

Siebgutauslass is discharged from the housing of the screening machine. This is the residue of the first sieve. Usually, this first fraction has relatively large particles. The first time sieved, remaining good, the Passage, then passes to a second screen deck. Here, a second fraction is separated with particles of slightly smaller size.

In order to move the Siebgut in motion and aufzulockern, is at

Screening machines of the aforementioned type provided a drive, the

Sieve structure and thus also on the screens located Siebgut one

Imposes wobbling motion. For this purpose, the sieve structure is usually via a central shaft, the one tangential to the shaft and radially inclined

Pivot pin drives, so moved that the screenings a combined throwing and swinging movement, just the wobbling movement, performs. In this case, a circular or elliptical oscillation becomes perpendicular to it

Movement component superimposed. This wobbling force exerts on the screenings forces that due to the changing radial and tangential inclination of the screen surface the screenings in a spiral movement over the

Let sieve surface wander. The wobble motion can be adjusted via the parameters speed, eccentricity, as well as radial and tangential inclination. Depending on the proportion of radial and tangential inclination changes

Dwell time of the screenings on the sieve. In addition to the drive types described above, the following drive types are also conceivable in vibrating screening machines:

Drive via unbalance motor, directly connected to the base cylinder of the screening machine. See, for example, the VRS series from Allgaier Werke GmbH. Further, as drive a foot motor into consideration, which is connected via a motor carrier with the base cylinder. Other types of drive are: a three-phase motor with unbalance eccentric disc, or a

Imbalance motor, clamped between two plates.

Regardless of the drive of the screening machine, the following applies: The screen structure is practically in a state of rest of the screening machine

Horizontal plane - vibrating screens - or he is against the Horizontal slightly inclined - at Taumelsiebmaschinen -. By switching on the drive, the sieve assembly is placed in a three-dimensional movement consisting of eccentricity, radial and tangential inclination. The speed,

Eccentricity, radial and tangential inclination differ depending on

Drive type or design.

The basic pattern of movement of the screen assembly is essentially a circular motion. Accordingly, tumble screening machines in the prior art are provided exclusively with circular screens or a cylindrical screen construction.

An interesting design of a tumbler screening machine is described in DE 10 2009 032 689 B3. The machine shown therein has a screen structure with at least one sieve, and a drive, the sieve structure a

Tumbling motion imprints that moves the screenings relative to the screen in motion. The drive engages the housing.

Another screening machine is described in WO 00/58 031 A2. Here, an active vibration exciter attacks on the housing and puts this in

Vibrations. In addition, a flywheel is provided, which is located below the Klassiergewebes, close to this, of a

Worn exciter thread. Is the housing through the mentioned

Vibration exciters excited to vibrate, so also vibrates said flywheel and thus transmits further vibrations on the

Klassiergewebe. The vibrations of the classifying fabric result in dislodging the granules of the granular bulk material from the classification fabric so that the grains perform a dance movement on the classifying fabric. As a result, the throughput of bulk material is increased by the screening machine. A similar screening machine has become known from US 8 485 364 B2. Also, this has an active vibrator, which acts on the housing, Furthermore, a passive vibrator in the form of a flywheel, which attacks the Klassiergewebe.

A similar solution has become known from DE 697 32 665 T2.

The problem of vibration generation is very serious in all screening machines, as it is for the performance of the screening machine, that is, the throughput of granular bulk material in the unit time, decisive. This is especially true in so-called tumble screening machines - see DE 10 2009 032 689 B3. Due to the wobbling movement, the single grain of the bulk material performs a spiral movement. It glides over the upper surface of the

Klassiergewebes, but it performs a little up and down movement. The invention has for its object to make a screening machine, in particular a tumbler, such that the hopping and dancing movement of the grains intensified during operation of the machine, and thus the throughput is increased by the machine. This object is achieved by a screening machine with the features of claim 1.

The main idea is to provide two active vibration exciters, namely a first, which acts on the housing of the machine, and a second, which acts on the sizing screen.

The prior art and the invention are explained in more detail with reference to the drawing. The following is shown in detail: FIG. 1 shows in elevation a known screening machine with an active and a passive vibration exciter. Figure 2 shows in elevation a known tumbler screening machine.

FIG. 3 shows a schematic representation of the screen construction of a

Taumelsiebmaschine invention.

FIG. 4 illustrates the path of a point of the sizing screen in FIG

Tumbler. FIG. 5 illustrates vibration patterns of the screen.

Figure 6 shows schematically of an inventive

Tumble screening machine, a first embodiment of the close-coupled active vibration exciter.

Figure 7 shows schematically of an inventive

Tumble Screen a second embodiment of a close-coupled active vibration exciter. The conventional screening machine shown in Figure 1 comprises a support structure 1 and a screen assembly 2. The screen assembly 2 comprises a housing 3 with a bottom 3.1, a cover 3.2 and a peripheral wall 3.3. The peripheral wall 3.3 is cylindrical. A circular Klassiersieb 4 is clamped in the peripheral wall 3.3. It divides the interior of the housing 3 into an upper and a lower area.

In the lid 3.2 is an inlet 3.2.1 for the good to be seen. In the peripheral wall 3.3 below the Klassiersiebes 4 is an outlet 3.3.1 for the sighted Good. Parallel to the sizing 4 below this a support wire 6 is arranged. This carries a flywheel 7.

If the housing 3 is excited by the active vibration exciter 5 to vibrate, the flywheel 7 performs a natural vibration, which is also transmitted to the sizing 4. It comes thus to a superposition of the vibration according to the active vibration exciter 5 and the

Self-oscillation of the flywheel 7. The screening machine shown in Figure 2 is a Taumelsiebmaschine with a

Majority of screen decks. All sieves are square. A support structure 1 is supported by springs 1.1 a base body 1 .2, on which the screen structure 2 rests.

The essence of the invention can be seen in FIG. It shows the screen structure 2 of a tumble screening machine, comprising a housing 3 with a bottom 3.1, a cover 3.2 and a peripheral wall 3.3.

In the peripheral wall 3.3 a sizing 4 is clamped. The sizing 4 is associated with a second active vibration exciter 50. This attacks directly or indirectly on the sizing 4.

The housing in turn has an inlet 3.2.1 and an outlet 3.3.1.

The two vibration exciters 5, 50 comprise a drive motor. This is speed-controllable. For example, the engine of the vibration generator 5 can rotate at a speed of 185-230 rpm, and the engine of the

Vibration generator 50 with a speed of 1000, 1500, 3000 U / min.

Deviations are possible in both cases upwards or downwards. The deflections are in the millimeter range. Figure 4 illustrates the web passing through a point P on the screen disk 4 during operation of the tumble screen machine. The point moves up and down the track on its way, except for the intersection with P

is marked. Here the point does not perform a vertical movement.

FIG. 5 has oscillation patterns. In this case, Figure 5a shows the vibration pattern of the screen assembly 2, generated by the active vibration exciter 5. Figure 5b shows the vibration pattern of the sizing 4 without the use of the active

Vibration generator 5, and Figure 5c shows the oscillation pattern of the

Classifying screen 4 when using the two active vibration exciters 5 and 50.

Figure 5c illustrates that the vibration when using both

Vibration generator 5, 50 has high amplitudes, and that they appear very irregular. The effect of the combined vibration by the vibration exciter 5, 50 is thus extremely strong. Over time, all grains of the granular bulk material are detected. The throughput of material to be classified is substantially greater than if only a single active vibration exciter were provided, optionally in combination with a passive vibration exciter as in the prior art.

FIGS. 6 and 7 illustrate in highly schematic form the second active vibration exciter 50 with associated components.

In Figure 6 can be seen the peripheral wall of the housing 3, also the

Classifying screen 4. The sizing screen 4 is supported by a support structure 10. This is fixed on the peripheral wall 3.3 via its outer edges. The

Supporting structure 10 carries the second active vibration exciter 50.

As FIG. 7 shows, a support sieve 6 can be provided between the classifying sieve 4 and the support structure 10. The support screen 6 has, for example, larger mesh widths than the sizing sieve 4. The mesh sizes of the support sieve. 6 can be so large that they do not affect the permeability of the sizing 4 at all.

It may be advantageous to arrange and design the sizing screen 4 and support screen 6 in such a way that these two can move freely parallel to one another, so that in practice a certain minimum relative movement can take place.

FIG. 8 shows the support structure 10 with the second active vibration exciter 50 acting thereon in a view from below, that is to say from the side facing away from the sizing screen 4. The support structure 10 has radial support arms 10.1 and concentric support rings 10.2, 10.3.

The vibration amplitudes should be in the millimeter range if possible.

reference numeral

1 supporting structure

1 .1 springs

1 .2 basic body

2 sieve construction

3 housing

3.1 soil

3.2 Lid

3.2.1 Inlet

3.3 peripheral wall

3.3.1 outlet

4 sizing strainer

5 first active vibration exciter

6 support screen

7 flywheel

10 support structure

10.1 support arms

10.2 support ring

10.3 support ring

50 second active vibration exciter

Claims

Patent claims

1 . Screening machine for classifying bulk materials, comprising the following features:

1 .1 a housing (3) with a base (3.1), a lid (3.2) and a peripheral wall (3.3);

1 .2 a classifying sieve (4), which divides the peripheral wall (3.3) into an upper and a lower wall part;

1 .3 a first active vibration exciter (5) which acts on the housing (3); and 1 .4 a second active vibration exciter (50), which acts directly or indirectly on the classifying screen (4).

2. Screening machine according to claim 1, characterized in that this is a tumbler screening machine.

Screening machine according to claim 1 or 2, characterized in that the oscillation frequencies and/or the oscillation amplitudes and/or the oscillation curves are different from one another.

4. Screening machine according to claim 3, characterized in that the

The vibration properties mentioned can be adjusted.

5. Screening machine according to claim 4, characterized in that the

The vibration properties mentioned can be adjusted during operation.

6. Screening machine according to one of claims 1 to 5, characterized

characterized in that there is a support structure (10) between the classifying screen (4) and the second active vibration exciter (50). Screening machine according to claim 6, characterized in that the support structure (10) comprises a support screen (6).