Screw machine and method for the processing of material to be processed

Patent metadata

Field	Value
Publication number	US-10882015-B2
Application number	US-201615764655-A
Country	US
Kind code	B2
Filing date	Sep 27, 2016
Priority date	Oct 1, 2015
Publication date	Jan 5, 2021
Grant date	Jan 5, 2021

Abstract

A screw machine includes an inductive heating device for the processing of material to be processed. The inductive heating device is used to heat the material in a heating zone. In the heating zone, at least one housing portion is made of an electromagnetically transparent material at least partly, the material being non-magnetic and electrically non-conductive, whereas at least one treatment element shaft is made of an electrically conductive material at least partly. During the processing of the material, the inductive heating device generates an alternating magnetic field that produces eddy current losses in the at least one treatment element shaft, the eddy current losses leading to a temperature increase of the at least one treatment element shaft. The material is heated on the at least one heated treatment element shaft, in particular until it melts. The screw machine allows a simple and efficient melting of the material, with the result that a mechanical energy input and a resulting wear of the screw machine can be reduced significantly.

First claim

The invention claimed is:

1. A screw machine comprising:
a housing comprising a plurality of interconnected housing portions arranged in succession in a conveying direction;
at least one housing bore formed in the housing;
a feed opening leading into the housing bores;
at least one treatment element shaft arranged in the at least one housing bore in such a way as to be drivable for rotation about a rotational axis;
an inductive heating device configured to form a heating zone, wherein at least one housing portion in the heating zone is at least partially made of a non-magnetic and electrically non-conductive material, the at least one treatment element shaft comprising an electrically conductive material at least in the heating zone, wherein the inductive heating device comprises at least one coil surrounding the at least one treatment element shaft, and the inductive heating device defines an inner space, and wherein only a non-magnetic and electrically non-conductive material is arranged between the at least one treatment element shaft and the at least one coil.

2. A screw machine according to claim 1 , wherein the at least one housing portion in the inner space is exclusively made of the non-magnetic and electrically non-conductive material.

3. A screw machine according to claim 1 , wherein the at least one housing portion comprises an inner sleeve, the inner sleeve at least partially defining the at least one housing bore in the heating zone, the inner sleeve being exclusively made of the non-magnetic and electrically non-conductive material.

4. A screw machine according to claim 1 , wherein the at least one housing portion comprises at least one outer part and an inner sleeve, the inner sleeve being supported against the at least one outer part.

5. A screw machine according to claim 4 , wherein the inner sleeve is supported against the at least one outer part on at least two support positions along the rotational axis.

6. A screw machine according to claim 4 , wherein the inner sleeve is formed negatively to the at least one coil on an outer side facing the at least one coil.

7. A screw machine according to claim 3 , wherein the at least one coil comprises an associated conductor, the inner sleeve having a thickness in a region of the conductor perpendicular to the rotational axis, wherein the thickness is greater than or equal to 5 mm and less than or equal to 50 mm.

8. A screw machine according to claim 3 , wherein the at least one coil comprises an associated conductor, the conductor having a non-round cross-section, which is at least partially formed linearly in relation to the inner sleeve.

9. A screw machine according to claim 1 , wherein the at least one treatment element shaft comprises a plurality of treatment elements arranged on at least one associated shaft non-rotatably and successively in the conveying direction, at least one treatment element comprising a metal heating layer, the metal heating layer forming a surface of the at least one treatment element, the at least one treatment element comprising an insulating layer, which thermally insulates the heating layer from the at least one associated shaft.

10. A screw machine according to claim 1 , wherein the inductive heating device comprises at least one coil, which is coolable by a cooling device.

11. A screw machine according to claim 1 , wherein the inductive heating device comprises at least one coil and an associated energy supply device, the energy supply device providing at least one of an alternating voltage and an alternating current.

12. A screw machine according to claim 1 , further comprising:
a temperature measuring sensor configured to measure a temperature of the material to be processed; and
a control device configured to control the inductive heating device in response to the measured temperature of the material to be processed.

13. A screw machine according to claim 4 , wherein the inner sleeve is supported against the at least one outer part on at least three support positions along the rotational axis.

14. A screw machine according to claim 4 , wherein the inner sleeve is supported against the at least one outer part on at least four support positions along the rotational axis.

15. A screw machine according to claim 11 , wherein the at least one of the alternating voltage and the alternating current has at least one of an adjustable frequency and an adjustable amplitude.

16. A screw machine comprising:
a housing comprising a plurality of interconnected housing portions arranged in succession in a conveying direction, said housing defining a housing bore and a feed opening extending into said housing bore;
a treatment element shaft arranged in said housing bore and configured for rotation about a rotational axis;
an inductive heating device arranged with one of said housing portions, said inductive heating device being configured to form a heating zone inside said housing bore, said inductive heating device including a coil surrounding said housing bore and said treatment element shaft, said one housing portion and said inductive heating device being formed to only have non-magnetic and electrically non-conductive material between said treatment element shaft and said coil.

Assignees

• Coperion Gmbh

Inventors

• Welb Sören
• Conrad Ulrich
• Munkes Peter

Classifications

• B01F2101/2805

  Mixing plastics, polymer material ingredients, monomers or oligomers · CPC title

• B01F35/93

  arranged inside the receptacle · CPC title

• B01F35/2215

  Temperature · CPC title

• B01F35/2115

  Temperature · CPC title

• B01F27/723

  the helices intermeshing to knead the mixture · CPC title