ARRANGEMENT AND PROCESS FOR TREATING A SURFACE

Abstract

An apparatus and method for treating a surface with a jet having a multiplicity of particles, including a mixing chamber with an inlet for a stream of propellant gas, the mixing chamber being designed to mix the stream of propellant gas with the multiplicity of particles, and a nozzle, which adjoins the mixing chamber and is connected to it in terms of flow and which has an outlet for the stream of propellant gas, a nozzle cross-sectional area of the nozzle as it progresses from the mixing chamber at first being reduced in size to a minimum nozzle cross-sectional area and then being increased in size again, the inlet having an inlet cross-sectional area, and an area quotient between the minimum nozzle cross-sectional area and the inlet cross-sectional area lying in the range from 10 to 300.

Claims

1.-9. (canceled)

10. An apparatus for treating a surface with a jet comprising a multiplicity of particles, the apparatus comprising: a mixing chamber with an inlet for a stream of propellant gas, the mixing chamber configured to mix the stream of propellant gas with the multiplicity of particles, and a nozzle, which adjoins the mixing chamber and is fluidically connected and which has an outlet for the stream of propellant gas, a nozzle cross-sectional area of the nozzle as it progresses from the mixing chamber at first being reduced in size to a minimum nozzle cross-sectional area and then being increased in size again, the inlet having an inlet cross-sectional area, and an area quotient between the minimum nozzle cross-sectional area and the inlet cross-sectional area lying in the range from 10 to 300.

11. The apparatus of claim 10, wherein the area quotient is in the range from 25 to 225.

12. The apparatus of claim 10, wherein the mixing chamber has a mixing chamber cross-sectional area that is at least as large as the inlet cross-sectional area and that is at least as large as the nozzle cross-sectional area at each position of the nozzle.

13. The apparatus of claim 10, wherein the inlet cross-sectional area is configured in a circular form, the nozzle cross-sectional area being configured in a circular form, and a diameter quotient between a minimum nozzle diameter of the minimum nozzle cross-sectional area and an inlet diameter of the inlet cross-sectional area is in the range from 4 to 17.

14. The apparatus of claim 10, wherein at least the mixing chamber and the nozzle are configured rotationally symmetrically about an axis of the arrangement.

15. The apparatus of claim 10, wherein the nozzle is configured as a Laval nozzle.

16. The apparatus of claim 10, wherein the particles are at least partly formed with solid carbon dioxide.

17. A process for treating a surface with a jet comprising a multiplicity of particles, utilizing the apparatus of claim 10.

18. The process of claim 17, the treating of the surface comprising at least one of the following steps: cleaning the surface, and removing flash or burr from the surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The invention and the technical environment are explained in more detail below on the basis of the FIGURE. The FIGURE shows a particularly preferred exemplary embodiment, to which however the invention is not restricted. In particular, it should be pointed out that the FIGURE, and in particular the relative sizes represented, are only schematic. In the FIGURE:

[0039] FIG. 1 schematically shows a lateral sectional representation of an arrangement for treating a surface.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0040] FIG. 1 shows a lateral sectional representation of an arrangement 1 for treating a surface with a jet comprising a multiplicity of particles. The arrangement 1 comprises a mixing chamber 2 with an inlet 3 for a stream of propellant gas. The mixing chamber 2 is designed to mix the stream of propellant gas with the multiplicity of particles. The arrangement 1 also comprises a nozzle 4 configured as a Laval nozzle 5, which adjoins the mixing chamber 2 and is connected to it in terms of flow and which has an outlet 7 for the stream of propellant gas. A nozzle cross-sectional area of the nozzle 4 as it progresses from the mixing chamber 2 is at first reduced in size to a minimum nozzle cross-sectional area and then increased in size again. The inlet 3 has an inlet cross-sectional area, an area quotient between the minimum nozzle cross-sectional area and the inlet cross-sectional area lying in the range from 10 to 300, preferably 25 to 225. In particular with regard to the area quotient, it should be pointed out that FIG. 1 is schematic and not to scale.

[0041] The mixing chamber 2 has a mixing chamber cross-sectional area that is larger than the inlet cross-sectional area and just the same size as the nozzle cross-sectional area at the transition between the mixing chamber 2 and the nozzle 4. The mixing chamber 2 and the nozzle 4 are configured rotationally symmetrically about an axis 6 of the arrangement 1. Therefore, the mixing chamber cross-sectional area can be described by way of a mixing chamber diameter 11. The mixing chamber cross-sectional area is at least the same size as the nozzle cross-sectional area at each position along the axis 6 of the nozzle 4. The inlet cross-sectional area and the nozzle cross-sectional area are configured in a circular form, a diameter quotient between a minimum nozzle diameter 10 of the minimum nozzle cross-sectional area and an inlet diameter 8 of the inlet cross-sectional area lying in the range from 4 to 17, preferably from 5 to 15. The minimum nozzle diameter 10 is defined as the smallest value of a nozzle diameter 9.

[0042] With the arrangement presented and the process presented for treating a surface, a particularly uniform, reproducible, effective and time-saving treatment of the surface can be achieved. This applies in particular to cleaning and removing flash or burr. The arrangement and the process may be used in particular in the production of wire or plastic products.

LIST OF DESIGNATIONS

[0043] 1 arrangement [0044] 2 mixing chamber [0045] 3 inlet [0046] 4 nozzle [0047] 5 Laval nozzle [0048] 6 axis [0049] 7 outlet [0050] 8 inlet diameter [0051] 9 nozzle diameter [0052] 10 minimum nozzle diameter [0053] 11 mixing chamber diameter

[0054] It will be understood that many additional changes in the details, materials, steps and arrangement of parts, which have been herein described in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims. Thus, the present invention is not intended to be limited to the specific embodiments in the examples given above.