Patent Application
20100302898
This application claims the benefit of German Application No Application No. 20 2009 004 866.7 filed. May 26, 2009, which is incorporated herein by reference for all purposes.
Mixers for heat treatment and/or for cooling a mixture of solid particles in a mixing vessel that has at least one heat-treatment central channel that at least partially gets in contact with the solid particles to be heat-treated are known. These mixers are typically used to cool a mixture of particles which has previously been mixed in a mixer. Therefore, such mixers are also designated as cooling mixers. Typically a so-called heating mixer is placed into the flow ahead of such a cooling mixer in the procedural chain. The product to be mixed is poured into it. In the course of the mixing process the particle mixture is heated by friction, so it then must be cooled to give the mixture further treatment. To do this the mixture is fed to a cooling mixer, which typically is attached directly to the outlet of a heating mixture. Such cooling mixers are often used with high-performance mixing systems for raw plastic products, such as powdered plastics for PVC manufacture.
Previously known cooling mixers have a vessel with a cooled inner wall. The vessel is designed with a dual wall, with cold water being channeled into or through the channels forming the dual wall. Therefore a part of a cooling channel forms the interior wall of the vessel, with the product for mixing being fed past this cooled wall section during the mixing process. In the vessel there are motor-driven mixing tools for circulating the mixture to be cooled. Thus, the mixing tools with their motor drive represent a circulating device to circulate the mixture to be cooled.
The vessel of such a cooling mixer typically has a circular cross sectional surface. The horizontal cooling mixer and vertical cooling mixture are different depending on a horizontal or a vertical alignment of the vessel. In both cases, the inner side of the annular wall of the vessel forms the cooling surface at which the mixture is cooled during circulation s by the mixing tools. Each mixing vessel has available two attachment connector pieces, one by which the cooling mixer is attached to the output of an upstream high-performance mixer, and another one for expelling the cooled material for mixing. With vertical cooling mixers, the filling connector piece is attached to the top cover flap. The emptying connecting piece is on the radial outer side of the annular sidewall. With a horizontal cooling mixture, the outlet connector piece and the filling connector piece typically are in the middle of the overall cylindrical cooling vessel, with the filling connector piece at or near the upper apex and the outlet connector piece at or near the lower apex of the mixing vessel.
Wear is observed on the vessel walls with known cooling mixers, particularly in the areas of the motion paths of the mixing tools, even if they do not actually touch the inner side of the vessel walls. This is not desirable. In addition, the cooled mixture can be contaminated by the material that is rubbing off. Care must be taken when such a cooling mixer is operated that the procedural time that is necessary to cool a batch of mixture is not longer than the procedural time needed to conduct complete the mixing, for example by an upstream heating mixer. This is especially true with mixing of a temperature-critical mixture. As for example, this is decisive when mixing powdered plastic for PVC manufacture. Inside the cooling mixer within such a procedure, not only must the inserted material for mixing be cooled to the needed temperature, but also the additional treatment must have been concluded, namely filling the vessel and expelling the cooled mixture.
It is desirable for the inserted material to be cooled as uniformly as possible when such a cooling mixer is in operation. Due to the placement of the outlet connector piece on the cooled wall of the vessel, this part of the vessel does not contribute to the cooling of the inserted mixture. Owing to this, in that area in which the material to be cooled is in contact with the inner vessel wall, cooling surface is lost.
It is expensive to clean such a previously known cooling mixture when one switches over from one material for mixing to be cooled to another one. This is due a portion of the mixture cannot be emptied using the normal means due to the geometry of the mixing vessel, and therefore remains in the mixing vessel. Additionally, the mobile tools for circulation must be cleaned.
The foregoing example of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.
On aspect of the present disclosure is to provide cooling mixer of the type named initially, in which the vessel is turnably supported about an axis that penetrates both of the front sides, and a motorized drive for turning the vessel is provided as the circulating device.
The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tool and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above described problems have been reduced or eliminated, while other embodiments are directed to other improvements.
In contrast to previously known cooling mixers with mixing tools rotating in a mixing vessel, this mixer has a turnably supported vessel. The turning of the vessel is motor-driven. The motor drive of the vessel forms the circulating device to circulate the mixture inserted into the vessel, or if additional components participate, at least partially so. Typically the vessel is turnable about its longitudinal axis, which at least during the mixing process is horizontal or approximately horizontal. Thus, during the mixing process, the axis of rotation penetrates the front sides of the mixing vessel. It is understood that the axis of rotation does not have to bodily penetrate the front sides of the mixing vessel. Rather, by this the position of the axis of rotation is meant. When the vessel rotates, the mixture inside it is circulated and is successively brought in contact with the inner jacket surface of the vessel. The entire vessel inner wall made available can be used as a usable cooling surface since preferably the vessel is driven to rotate. Since the entire inner vessel wall can be a thermal treatment surface, the mixing vessel and thus the mixer as a whole can be more compact. For the purposes of cooling, generally the entire inner wall of the thermal treatment mixer is not in contact with the temperature-treated mixture at one time, for example to be cooled. With a rotationally driven mixing vessel, the mixture to be temperature-treated is in contact with only a portion the inner vessel wall at one time. The result of this is that each vessel wall section is cyclically in contact with the mixture only over a certain segment of rotational angle. For a mixer designed as a cooling mixer, this means that a section of the vessel inner wall that is rotated out from the mixture and is cooled overall in the course of further rotary motion and continuing cooling, before this section of the vessel inner wall is again in contact with the mixture to be cooled. Then, due to the turning motion of the vessel inner wall, the inner wall section cooled off in this way again contacts the mixture to be cooled in this embodiment example. This explains the especially effective and therefore time-saving cooling. The same is true in reverse fashion for a case in which material for mixing is to be heated with such a mixer. Fundamentally an oscillatory drive of the vessel is also conceivable, with oscillatory motion preferably performed until at least the peripheral vessel sections that point in the direction of motion are brought out of the material for mixing in the course of the oscillatory motion.
In the depicted embodiment, the mixer is designed as a cooling mixer. Fundamentally this requires no mixing tools, and in particular no driven mixing tools. In contrast to previously known cooling mixers, with this cooling mixer, little or no heat is infused into the mixture during the circulation. This phenomenon is observed with the previously known cooling mixers. For this reason with the cooling mixer according to the present disclosure, a more effective cooling is possible. The attachment connector pieces necessary to attach the mixing vessel to a feed for material for mixing as well as an outlet line typically are located on the front sides of the preferably cylindrical vessel. With this cooling mixer, the entire cylindrical jacket surface can be used as a cooling surface.
According to one embodiment example, provision is made that the vessel is supported to swivel about an axis running transverse to its turning axis in addition to being rotatable. This pivoting suspension of the vessel permits the vessel to be adjusted from a filling setting into a mixing setting with a longitudinal axis that is horizontal or runs slightly inclined thereto. Then the mixing vessel can be pivoted out of its mixing setting into an emptying setting, in which the cooled mixture can be drained from the vessel. The emptying setting can be the same as the filling setting, or different from it. In a configuration in which the mixing vessel assumes a different position during mixing than in its filling setting and/or its emptying setting, attachment connector pieces are used that are designed as couplings for removable attachment onto complementary couplings of a mixture feed or a drain line. The flaps or valves necessary to close or open a feed-in or -out of the two coupling parts can be opened or closed manually or by use of an actuator-impinging setting adjustment medium such as air. The pivoting support of the vessel also permits a configuration in which the mixing vessel has only a single attachment connecting piece, via which the vessel can be filled and also emptied. Then filling, the vessel is brought into a position such that from the material-for-mixing feed the mixture can drain from above into the vessel. Through pivoting, this attachment connector piece can be brought into a downward pointing direction to empty the vessel. Typically the vessel's mixing setting is between these two end settings.
The vessel according to one embodiment example is seated in a rack, vis-à-vis which the vessel is pivotable. For turnable support, a roller seating can be provided, with the vessel in typical fashion having guide rails available with such a configuration, into which the rollers of the roller seating engage. At least one of these rollers is motor-driven for turning the vessel. With such a configuration, the rollers not only function to provide turnable support for the rotating vessel, but they also hold the vessel, through their engagement into the guide rails, when it is pivoting about its pivoting axis running transverse to the turning axis. Then the guide rails are suspended on the rollers of the roller seating. In one embodiment the guide rails are designed as U-guides that are open outward in the radial direction, with the gap of the side walls corresponding to the thickness of a roller engaging therein. Instead of, or in addition to the seating described, holding rollers and/or pairs of holding rollers can be provided to hold the turnable mixing vessel. These typically engage on the outer sides of at least one guide rail, so that at least a share of the weight of the mixing vessel is eased in a non-horizontal direction via the holding roller or pairs of holding rollers into the rack.
The inner wall of the vessel can be profiled by baffles, preferably in a longitudinal-axis direction, with these baffles in appropriate fashion being designed as coolant channels. By this means, the inner surface of the vessel, and thus the cooling surface made available, is enlarged. These baffles improve not merely the cooling performance, but also improve circulation of the material for mixing to be cooled that is found therein.
In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.
Before explaining the disclosed embodiment of the present invention in detail, it is to be understood that the invention is not limited in its application to the details of the particular arrangement shown, since the invention is capable of other embodiments. Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than limiting. Also, the terminology used herein is for the purpose of description and not of limitation.
A thermal-treatment mixer designed as a cooling mixer 1 has a mixing vessel 2, which is pivotable by means of an adjustment cylinder 3 about a horizontally running pivoting axis S (see
As can be seen in
Mixing vessel 2 is held in a pivoting rack 14 which pivots on a base rack 15 by means of the adjustment cylinder 3 previously described. Thus adjustment cylinder 3 is braced on one side on ground rack 15 and on the other side on pivoting rack 14, as is especially evident in
In an additional embodiment example, instead of profiling guide rails 16, 16.1 being U-shaped, they can have closed guide profiles, especially rectangular ones. In this configuration, the roller drive is designed so that the motor-driven roller typically engages on the side facing outward, and the guide rail runs between two additional guide rollers.
Corresponding stops and/or sensors and/or microswitches are attached on the material-for-mixing feed 5 for positionally exact pivoting of mixing vessel 2 by actuating adjustment cylinder 3. The actuators for opening the particular flaps or valves in material-for-mixing feed 5 and in the filling connector piece 6 or in the coupling piece related to this can only be actuated for opening if according to their purpose, the two coupling members are in engagement with each other. The filling connecting piece 6 couples in fully automatic fashion to the material-for-mixing feed.
The front side 20 of mixing vessel 2 opposite front side 7 is also designed as a flap shaped like a truncated cone. R. Front side 20 has an emptying connecting piece 21 which is eccentric relative to rotational axis, by means of which the cooled material for mixing can be emptied from mixing vessel 2. A part of emptying connecting piece 21 is also a locking element, through which emptying connecting piece 21 is closed when not used. Just like the locking element in filling connecting piece 6, the locking element in emptying connecting piece 21 is able to be pneumatically activated in the depicted embodiment example. A rotary transmission lead-through 22 is placed centrically with, and thus aligned with, rotational axis 4 of mixing vessel 2 on front side 20. Rotary transmission lead-through 22 transfers pressurized air made available from the stator side to the actuators placed on turnably supported mixing vessel 2, namely the actuators for operating the locking elements in filling connecting piece 6 and emptying connecting piece 21.
For carrying out the actual mixing process, mixing vessel 2 is pivoted by adjustment cylinder 3 relative to its setting shown in
During the cooling process, feed line 12 and therefore inlet 10 attached on the vessel side, is impinged on by cooling liquid, water for example, at a certain pressure. The cooling water is injected via inlet 10 into the coolant channel integrated into the dual wall of mixing vessel 2. Provision can be made that vessel 2 has multiple circulatory loops of coolant. The heated cooling water guided back via return 11 from the circulatory coolant loop is removed via return 11, rotary transmission lead-through 9 and drain line 13.
Using an embodiment example,
The cavity situated between outer wall 23 and inner wall 24 is subdivided by multiple partitions 25 into individual coolant channels K. In the embodiment example shown in
Inner wall 24 is roughened by hollow strips L projecting inward in the radial direction. The hollow strips L are each a part of a coolant chamber K. Owing to this measure, not only is the inner surface of inner wall 24 and thus the surface made available for cooling expanded, but also the hollow strips L provide support to the circulation process of the material for mixing inserted into it when mixing vessel 2 is rotated.
It is understood that the concept of mixing vessel 2, as shown in
After the mixing process has been carried out, mixing vessel 2 is again brought to its filling and emptying setting shown in
The previously described configuration of the interior of mixing vessel 2, with its hollow strips L following the long dimension, which extend in essence over the cylindrical section of mixing vessel 2 and the inclined placement for emptying shown in
In a further embodiment example,
In the depicted embodiment example, each hollow strip L″, L′″ in the area of its inlet and drain, as well as in a central area on the mixing vessel wall, is attached in the manner previously described. The center attachment found between the two end attachments serves only for holding a hollow strip L″ or L′″, while the two end attachments are provided in addition for attachment to the circulatory coolant flow circuits.
From the
In a perspective view,
The
The concept of arranging hollow strips within mixing vessel 26 as described in
There also exists an option, through replacement of individual hollow strips within such a vessel, as described for the embodiment example 6 to 9, to adapt such to various circumstances. Thus for example by installation of larger hollow strips, and thus of strips with a larger heat-treatment surface, the mixer has the capacity for greater performance. With the concept of a cooling mixer as described for
The concept described in the embodiment example of
The hollow strips L″″ of mixing vessel 35 are placed at intervals to the inner wall 36 of mixing vessel 35 designed with dual walls. Thus, between inner wall 36 of vessel 35 and the hollow strips L″″, a gap 37 is found, as
Depending on the particular pre-set or adjusted gap with between the hollow strips L″″ and inner wall 36 of mixing vessel 35, the feeding performance of hollow strips L″″ is adjustable. The rate at which mixing vessel 35 is rotationally driven can serve as a further variable to determine feed performance.
The material moves through the gap between hollow strip L″″ and the inner wall 36, against the turning direction 39 of mixing vessel 35 over a relatively large turning angle range, so that the cooling power of mixing vessel 35 thus designed is especially effective.
The mixing vessels described in
From the specification of the invention it is clear that since no movable parts are placed within the mixing vessel, which contrasts with previously known mixers, the danger of sparks being formed is reduced to a minimum.
The invention has been described by way of example using cooling mixers. In the same way, the mixer described can also be used for heating a material for mixing. With such a concept, the cooling medium accesses described in the previous embodiment examples are impinged on by a medium that is at a higher temperature than the temperature of the material for mixing.
While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations therefore. It is therefore intended that the following appended claims hereinafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations are within their true sprit and scope. Each apparatus embodiment described herein has numerous equivalents.
The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed. Thus, it should be understood that although the present invention has been specifically disclosed by preferred embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention as defined by the appended claims. Whenever a range is given in the specification, all intermediate ranges and subranges, as well as all individual values included in the ranges given are intended to be included in the disclosure. When a Markush group or other grouping is used herein, all individual members of the group and all combinations and subcombinations possible of the group are intended to be individually included in the disclosure.
In general the terms and phrases used herein have their art-recognized meaning, which can be found by reference to standard texts, journal references and contexts known to those skilled in the art. The above definitions are provided to clarify their specific use in the context of the invention.
All patents and publications mentioned in the specification are indicative of the levels of skill of those skilled in the art to which the invention pertains. All references cited herein are hereby incorporated by reference to the extent that there is no inconsistency with the disclosure of this specification. Some references provided herein are incorporated by reference herein to provide details concerning additional starting materials, additional methods of synthesis, additional methods of analysis and additional uses of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 20 2009 004 866.7 | May 2009 | DE | national |
