DE19623890C1 - Method for homogenisation of powder-form material using ultra-sound - Google Patents

Abstract

The sonotrode (1) vibrates with an adjustable amplitude (A). The angle of inclination (alpha) of the gap (4) and the gap length (B) are adjustable. The sonotrode has a rectangular cross-section and the run-in edge (5) for the powder-form material (3) is formed as a blade. The run-in edge is treated with a hard metal or a ceramic material. The fixed base (2) for increasing the transport amount is formed as a rotating roller.

Description

The invention relates to a method according to claim 1 for homogenizing powdery Materials using ultrasound, the grain size reduced or unified or in which agglomerates to be destroyed, and a device for performing of the method according to claim 1.

Known methods use to homogenize powdered materials mills, for example spherical  or roller mills, or screens, the perforations of which correspond to the desired grain sizes.

Mills and / or sieves can have a high maintenance wall due to contamination may be necessary Mills experience a high level of wear with regard to grinding work one. The regulation of the desired grain size is not continuously possible.

In US 3, 223, 337 an apparatus for Powdery granular material using ultrasound excited vibrating body described. It will proposed to put the granular material in via a funnel a gap between two opposite walls to introduce, which by means of two transformers and an oscillator excited to ultrasonic vibrations are. The construction of the device is complicated and unreliable. The powdery material can be between press the opposite walls so hard that the gap is blocked by wedge formation of the material and further material flow is hindered or even comes to a standstill.

It is an object of the present invention eliminate undesirable side effects and a Method and device for carrying out the Process for homogenizing powder To create materials with a high Productivity, low wear and tear continuous regulation of the grain sizes are guaranteed.

The solution to this problem arises from the  Features of claim 1 or claim 4.

Through the direct application of ultrasound, a Process demonstrated with an almost wear-free and one about setting the Vibration amplitude of the sonotrode almost infinitely variable and easily controllable homogenization of powdery materials to uniform defined grain sizes is guaranteed.

The material throughput can be changed by a The gap inclination angle and the gap length also can be regulated continuously.

Further advantageous embodiments of the invention result from the subclaims.

The invention is based on one in the Drawings shown embodiment of a Device for performing the method closer explained. It shows:

Fig. 1 is a schematic diagram of the device for performing the method according to the invention and

Fig. 2 shows an advantageous embodiment of one of the edges of the sonotrode.

In FIG. 1, the basic structure of an apparatus for performing the method is shown according to the invention. The ultrasonic vibrator 1 (sonotrode), which is of rod-shaped design with a rectangular cross-section, carries out vibrations with an adjustable amplitude A perpendicular to the spring-loaded fixed support, plate 2 . The sonotrode 1 only taps the plate 2 with each vibration due to its inertia.

The sonotrode 1 and the plate 2 form a gap 4 of the gap length B with an adjustable inclination angle α.

The amplitude A of the sonotrode vibrations determines the grain size, ie the opening created at point C between the plate 2 and the sonotrode 1 is determined by the chosen oscillation frequency.

The grain size of the powdery material increases increasing amplitude of the vibrations also increases.

The vibrations of the sonotrode 1 create a suction in the gap 4 , through which the powder is drawn and thereby shredded to the desired grain size on a cutting edge 5 of the sonotrode 1 . The suction strength, and thus the material throughput, can be determined by the gap angle α and by the gap length B. The result is an optimum at a specific gap angle α, which also depends on the effective vibration surface of the sonotrode 1 .

The transport amount of the powdery material to the gap 4 can be increased by the solid base 2 being designed as a rotating roller.

The edge of the sonotrode 1 tapping on the plate 2 can be designed as a cutting edge 5 , for example by coating this edge 5 or using it with a hard metal 6 or with a ceramic material. Such an embodiment is shown by way of example in FIG. 2.

There can be different grain sizes of a powder shaped material to a defined uniform Grain size, which of course is only the smallest available  or a smaller grain size will. It can have an existing uniform grain size brought to a smaller uniform grain size or agglomerates present in the powder smashed to the defined uniform grain size will.

Claims (6)

1. A method for homogenizing powdery materials by means of ultrasound, characterized in that the powdery material ( 3 ) in a gap ( 4 ) of defined length (B) and with a defined angle of inclination (α) between a solid base ( 2 ) and one an amplitude (A) vibrating sonotrode ( 1 ) is introduced. 2. The method according to claim 1, characterized in that the amplitude (A) of the sonotrode ( 1 ) is adjustable. 3. The method according to claims 1 and 2, characterized in that the angle of inclination (α) of the gap ( 4 ) and the gap length (B) are adjustable. 4. Device for performing the method according to claims 1 to 3, characterized in that the sonotrode ( 1 ) with a rectangular cross section and the leading edge ( 5 ) of the sonotrode ( 1 ) for the powdery material ( 3 ) are designed as a cutting edge . 5. The device according to claim 4, characterized in that the leading edge ( 5 ) is treated with a hard metal ( 6 ) or a ceramic material. 6. The device according to claim 4, characterized in that the fixed base ( 2 ) is designed to increase the amount of transport as a rotating roller.