DEVICE FOR PRODUCING A MULTI-COMPONENT MIXTURE AND METHOD FOR OPERATING SAID TYPE OF DEVICE

Abstract

The invention relates to a device for producing a multi-component mixture, comprising a mixing chamber and a mixing device, wherein the mixing device has a stirrer which is arranged in the mixing chamber and which is rotatably driven about an axis of rotation L, wherein a temperature control channel system for controlling the temperature of the stirrer and through which a temperature control medium can flow is arranged inside the stirrer.

Claims

1. A device for producing a multi-component mixture, the device comprising a mixing chamber and a mixing device, wherein the mixing device has a stirrer which is arranged in the mixing chamber and is rotatably driven about an axis of rotation (L), wherein a temperature control channel system through which a temperature control medium can flow is arranged inside the stirrer for the purpose of controlling the temperature of the stirrer.

2. The device according to claim 1, wherein the stirrer is arranged on a shaft which is connected to the stirrer in a region of a first end of said shaft and is rotatably driven in a region of a second end of said shaft.

3. The device according to claim 1, wherein the temperature control channel system is arranged in cavities of the stirrer, and walls of the cavities form walls of the temperature control channel system.

4. The device according to claim 3, wherein the shaft has a temperature control channel system which is fluidically connected to the temperature control channel system of the stirrer, wherein an inflow portion and an outflow portion for the temperature control medium are provided in the region of the second end of the shaft.

5. The device according to claim 1, wherein the temperature control channel system is formed in a temperature control lance which is arranged in a cavity of the stirrer.

6. The device according to claim 5, wherein the temperature control lance is guided in a cavity of the shaft up to its second end, and an inflow portion and an outflow portion for the temperature control medium are provided in the region of the second end of the shaft.

7. The device according to claim 5, wherein the temperature control lance has a pipe in its interior, a supply flow portion of the cooling channel system being formed outside the pipe and a return flow portion being formed inside the pipe.

8. The device according to claim 1, wherein the temperature control channel system is formed by means of a heat pipe which is arranged in a cavity of the stirrer.

9. The device according to claim 8, wherein the heat pipe is guided in a cavity of the shaft up to its second end, and active temperature control of the heat pipe is provided in the region of the second end of the shaft.

10. A method for producing a multi-component mixture comprising steps of: adding multiple components to the mixing chamber of the device according to claim 1; stirring the components in the mixing chamber with the stirrer; and controlling temperature of the stirrer by flow of the temperature control medium through the temperature control channel system.

11. The method according to claim 10, wherein the temperature of the stirrer is controlled by removing heat from an interior of the stirrer by means of a temperature control medium.

Description

[0026] Embodiments of the invention are explained in more detail below with reference to schematic drawings.

[0027] FIG. 1 shows a device for producing a multi-component mixture according to a first embodiment of the invention;

[0028] FIG. 2 shows a device for producing a multi-component mixture according to a second embodiment of the invention and

[0029] FIG. 3 shows a device for producing a multi-component mixture according to a third embodiment of the invention.

[0030] The device 1 for producing a multi-component mixture according to FIG. 1 comprises a mixing chamber 2 and a mixing device 3. The mixing device 3 comprises a stirrer 4 which is arranged in the mixing chamber 2 and is rotatably driven about a longitudinal axis L by a shaft 12. The stirrer 4 is responsible for actively mixing together various components of a multi-component mixture, which components are introduced into the mixing chamber 2 through ducts (not shown). The multi-component mixture is in particular a plastics material.

[0031] The fully prepared multi-component mixture can be removed from the mixing chamber through an outlet 15, the outlet 15 being closed and opened by the stirrer 4 which can be moved in the axial direction.

[0032] The stirrer 4 has a first end 10 by means of which the outlet 15 can be closed. It also has a second end 11 which is connected to a first end 13 of the shaft 12. A second end 14 of the shaft 12 has a drive (not shown).

[0033] In order to keep the soiling of the stirrer 4 caused by the crosslinking of the material in the mixing chamber 2 to a minimum, the stirrer 4 is cooled from the inside. The walls of the mixing chamber 2 can also be provided with cooling channels that allow the mixing chamber 2 to be cooled.

[0034] For cooling, the stirrer 4 has a cavity 23 which is delimited by walls 9 and extends from the second end 11 of the stirrer 4 almost to its first end 10. A cooling channel system 5 is formed in the cavity 23 as a temperature control channel system, the walls 9 of the cavity also forming walls of the cooling channel system 5 in the embodiment shown in FIG. 1. The cooling channel system 5 is thus formed by the walls 9 of the cavity 23 and additionally by a pipe 8 which is arranged coaxially in the cavity 23. As an alternative to the variant shown here, an apparatus that heats the stirrer from the inside is also conceivable in a heating channel system as a temperature control channel system. This can have comparable features to the shown cooling channel system 5, with a through-flow of a heating medium being expedient in this case.

[0035] In this way, both a supply flow portion 6 which is connected to an inflow portion 16 in the region of the second end 14 of the shaft 12 and a return flow portion 7 which is connected to an outflow portion 17 in the region of the second end 14 of the shaft 12 are formed in the cavity 23. A temperature control medium which is used as the cooling medium, for example water, flows through the cooling channel system 5 formed in this way, as indicated by the arrows 25. The cooling medium flows through the inflow portion 16 into a cavity 27 that extends inside the shaft 12, and from there flows into the cavity 23 of the stirrer 4, which stirrer cavity is fluidically connected to the cavity 27. In this case, the cooling medium flows between the pipe 8 and the walls 9 of the cavity 27, 23 into the region of the first end 10 of the stirrer 4, where it flows into the pipe 8, from there flows into the pipe 28 within the shaft 12, and from there flows to the outflow portion 17.

[0036] In the region of the supply flow portion 6, the cooling medium absorbs heat from the material of the stirrer 4 and in so doing cools the surface 29 thereof. Heated cooling medium is transported away in the return flow portion 7.

[0037] FIG. 2 shows a second embodiment of the device 1, which differs from that shown in FIG. 1 in that a temperature control lance designed as a cooling lance 18 is arranged in the cavity 23, 27. This lance extends from the region of the first end 10 of the stirrer 4 up to the region of the second end 14 of the shaft 12. The cooling lance 18 also has a pipe 19 in its interior, a supply flow portion 6 of the cooling channel system 5 being formed outside the pipe 19 and a return flow portion 7 being formed inside the pipe 19. In the region of the second end 14 of the shaft 12, the cooling lance 18 comprises openings of an inflow portion 20 and an outflow portion 21.

[0038] The cooling lance 18 can be inserted or screwed into the stirrer 4 and/or the shaft 12, for example. When the stirrer 4 is replaced, the cooling lance 18 can remain connected to the shaft 12.

[0039] In order to achieve particularly good heat transfer and thus particularly good cooling performance, a gap between the outer walls of the cooling lance 18 and the walls 9 delimiting the cavity 23 is designed to be as small as possible.

[0040] FIG. 3 shows a third embodiment of the device 1, which differs from the embodiments shown in FIGS. 1 and 2 in that the cooling channel system 5 is formed by means of a heat pipe 22 which is arranged in the cavity 23, 27 and extends from the region of the first end 10 of the stirrer 4 into the region of the second end 14 of the shaft 12. A distal end 26 of the heat pipe 22 can have active cooling means 24.

[0041] In the embodiment shown, the heat pipe 22 is shown only schematically. This is a heat transport means known to a person skilled in the art in which, during operation, a working medium held in the heat pipe 22 evaporates in the region of the stirrer 4 and flows into a cooling zone located in the region of the distal end 26, where it releases heat and condenses again. In this way, the heat pipe 22 forms a closed system which is particularly simple to integrate into the stirrer 4 and the shaft 12.

[0042] Like the cooling lance 18 according to FIG. 2, the heat pipe 22 can be screwed or plugged into the stirrer 4 and/or the shaft 12 and remain connected to the shaft 12 when the stirrer 4 is replaced. A gap between the outer walls of the heat pipe 22 and the walls 9 delimiting the cavity 23 is designed to be as small as possible for efficient cooling.

LIST OF REFERENCE SIGNS

[0043] 1 device [0044] 2 mixing chamber [0045] 3 mixing device [0046] 4 stirrer [0047] 5 cooling channel system [0048] 6 supply flow portion [0049] 7 return flow portion [0050] 8 pipe [0051] 9 wall [0052] 10 first end [0053] 11 second end [0054] 12 shaft [0055] 13 first end [0056] 14 second end [0057] 15 outlet [0058] 16 inflow portion [0059] 17 outflow portion [0060] 18 cooling lance [0061] 19 pipe [0062] 20 inflow portion [0063] 21 outflow portion [0064] 22 heat pipe [0065] 23 cavity [0066] 24 cooling means [0067] 25 arrow [0068] 26 distal end [0069] 27 cavity [0070] 28 pipe [0071] 29 surface [0072] L axis of rotation