[0001] The present invention relates to a mixer with a drum that comprises a mantel, a bottom
and a top and which rotates around an axis of rotation. The present invention further
relates to a method for heating the rotating drum of a mixer.
[0002] Such mixers are known from the state of the art and for example produced by the applicant
of this patent application. These mixers are particularly utilized for dry mixing,
for example of chemicals, food products or the like. In the past, these mixers have
been indirectly heated, i.e. the heating medium does not get into contact with the
product to be mixed, with water or oil as a heating medium. However, the maximum temperature
up to which the mixer can be heated with these transfer media and/or the heat transfer
is limited.
[0003] It was therefore the objective of the present invention to provide a mixer that can
be heated to higher temperatures than mixers according to the state of the art and
which is easy to build, to clean and/or to maintain.
[0004] This objective is attained with a mixer with a drum that comprises a mantel, which
is closed at both ends and which rotates around an axis of rotation, whereas the drum
is indirectly heated with steam and/or heated or cooled with water and/or any other
fluid medium.
[0005] The present invention relates to a mixer, this mixer comprises a drum, which rotates
around an axis of rotation, which is preferably arranged horizontally. The rotation
of the drum can be continuous or discontinuous. The drum can rotate around the axis
of rotation clockwise or counterclockwise. The drum of the mixer comprises a mantel,
which is preferably shaped cylindrically and which is closed at both ends, for example
with a column-plate. The drum is preferably made from steel, particularly from stainless-steel.
[0006] According to the present invention, the drum is heated indirectly with steam, i.e.
the product to be mixed is, during the mixing process, never in contact with this
heating-steam. During the heating of the drum, the steam condensates at least partially
and this condensate is removed from the mixer without touching the product. The person
skilled in the art understands, that steam can be added to the product inside the
drum in case the recipe requires the addition of steam.
[0007] Preferably, the drum comprises at least one, preferably a multitude of internal mixing
means. Such an internal mixing means is for example a plate, which is preferably bent.
Each internal mixing means is preferably fixed to the drum and more preferably co-rotates
together with the drum. Even more preferred, the inventive mixer does not comprise
any mixing means which move relative to the drum.
[0008] Preferably at least one such internal mixing means and/or the mantel of the drum
are heated with steam. Preferably, each internal mixing means comprises one steam
inlet and one condensate outlet. The mantel comprises preferably one two or more hollow
segments which can be subjected to steam, preferably individually. In case water is
used as a heat transfer medium, preferably two or more individual segments are provided.
Preferably, the internal mixing means are at least partially hollow. In this hollow
volume, the steam is injected and heats the sidewall of the internal mixing means.
The mantel comprises preferably two sidewalls, preferably concentric sidewalls, which
are spaced apart. In this hollow volume steam and/or water is injected, for example
to heat and/or cool the inner sidewall of the mantel. In case of water as a heat transfer
medium, the hollow volume between the sidewalls is preferably divided in two or more
individual segments. Each segment extends preferably essentially over the entire length
of the mantel and more preferably along only a part of the circumference of the inner
sidewall. Each segment preferably comprises a steam-inlet and a condensate outlet.
The segments are operated in parallel. These segments can be operated in series, for
example, in case water is inserted into the hollow volume between the sidewalls.
[0009] In a preferred embodiment of the present invention, condensate is removed from each
internal mixing means and/or the mantel via a collecting volume, preferably a collection
pipe, which is connected to the condensate discharge of one, preferably each, internal
mixing means and/or the condensate discharge from the mantel. The collecting volume
co-rotates with the drum. Preferably, the collecting volume, preferably the collecting
pipe, has the same shape as the circumference of the mantel of the drum. More preferably,
the collecting volume, preferably the collecting pipe, is at least partially ring-shaped.
In an even more preferred embodiment of the present invention, the cross section of
the collecting volume, preferably the collecting pipe, is closed at one position,
at least partially. Preferably, one of the ends, more preferably both ends of the
collecting volume, preferably the colleting pipe, are closed. Preferably, the collecting
volume, preferably the collecting pipe, extends at least partially, more preferably
entirely beyond the circumference of the drum, i.e the distance of the colleting volume
from the centerline is at least locally, preferably entirely, larger than the distance
of the mantel of the drum from this centerline.
[0010] Preferably, internal mixing means comprise a condensate collection area in which
the condensate is collected before it is discharged. More preferred, the condensate
collection area is tilted towards the condensate discharge.
[0011] The person skilled in the art understands that, in case the mixer is heated or cooled
with water and/or oil, in the entire disclosure the subject matter "steam" and "condensate"
has to be substituted by the subject matter "water and/or oil and/or any other fluid
medium". Particularly, the steam inlet is the water/oil-inlet, whereas the condensate
outlet, the condensate collection and/or condensated discharge is the water/oil outlet,
water/oil collection and/or the water/oil discharge.
[0012] Another subject matter of the present invention is a method for heating the rotating
drum of a mixer, with steam, whereas condensate is removed from the mixer discontinuously.
[0013] The disclosure made regarding the inventive mixer also applies to the inventive method
and vice versa.
[0014] According to inventive method of the present invention, the condensate is removed
from the mixer discontinuously. Preferably, the discharge takes only place in certain
rotational positions of the drum, preferably limited to a rotational segment of <180°,
more preferably < 150° and even more preferably < 120° and even much more preferred
< 90°.
[0015] According to another or a preferred embodiment of the present invention, the condensate
is discharged from the mixer, from the internal mixing means and/or from the mantel
at least temporarily, preferably entirely, by gravity, i.e. no pump is needed to discharge
the condensate.
[0016] The disclosure made regarding the inventive mixer and the inventive method also applies
to this inventive method and vice versa.
[0017] According to a preferred or another embodiment of the present invention, the mixing
means and/or at least a segment of the mantel of the drum is heated with steam and
the condensate is removed from the mixer and/or from the internal mixing means and/or
from the mantel and/or only once per rotation of the drum.
[0018] The disclosure made regarding the inventive mixer and the inventive method also applies
to this inventive method and vice versa.
[0019] The inventions are now explained according to fig. 1 - 7. These explanations do not
limit the scope of protection. The explanations apply to all inventions likewise.
Fig. 1 shows the inventive mixer.
Fig. 2 shows construction details of the mixer according to fig. 2.
Fig. 3 - 7 show enlarged drawings shown in fig. 2.
[0020] Fig. 1 shows the inventive mixer 1. This mixer comprises a drum 10 with a mantel
2, which is in the present case cylindrical. The mantel 11 is closed at its first
and second end 3, 4 by a bottom plate. For mixing purposes, the drum rotates around
its axis of rotation 5. In the present case, the mantel 2 of the drum 10 comprises
two side walls, which are arranged concentrically and which are spaced apart, so that
there is a hollow volume between the two side walls of the drum. Inside, the inventive
mixer comprises at least one mixing means 6, which improves the mixing of products
within the drum. As can be particularly seen from fig. 3, this mixing means 6 is hollow,
so that steam can be injected into the mixing means 6. In the present case, the hollow
volume between the first and the second side wall of the mantel 2 is divided in two
separate segments. Each segment extends essentially over the entire axial length of
the drum 10 but extends radially only over a segment of a circle. Each of these segments
comprises a steam supply 12. 3, which is, in the present case, connected to a steam
distribution pipe 12.1, which has, in the present case, the shape of a ring. The internal
mixing means 6 is also connected to a steam supply via the pipe 12.2 which is also
connected to the distribution pipe 12.1. Between the steam inlet 12 and the distribution
ring 12.1, a connecting pipe 12.4 is arranged. The steam supply to the segments of
the mantel and the internal mixing means 6 is operated preferably in parallel. The
steam can be fed to the mixer continuously or discontinuously. During the heating
of the mixer the steam supplied condensates and this condensate has to be removed
from the internal mixing means 6 as well as from the hollow segments of the mantel
2. For this purpose, each internal mixing means comprises a condensate discharge pipe
8 and each hollow segment of the mantel comprises a condensate discharge pipe 9. The
pipes 8, 9 are connected to a condensate collection pipe 7, respectively, in which
the condensate is collected prior to discharging from the mixer. In the present case,
the condensate collection pipe 7 is designed as a ring, whose radius is larger than
the external radius of drum 10. The cross section of this pipe 7 is closed at least
partially, preferably entirely, at one position 16, preferably between the two ends
7.1 of the pipe 7. From this pipe 7 a discharge pipe extends from the collection pipe
7 here to the center of the drum, through which the condensate which has been collected
in the collecting pipe 7 is discharged to the ambient.
[0021] The operation of the inventive mixer is as follows:
The mixing material is added and discharged to the drum 10 continuously or batchwise.
During the mixing the drum 10 rotates here counter-clockwise as depicted by arrow
11. In order to heat drum 10, steam is supplied via the steam inlet 12. From there
the steam flows via pipe 12.4 to the ,here ring-shaped, steam distribution pipe 12.1.
To this steam distribution pipe 12.1 a multitude of pipes 12.3, 12.2 are connected,
which supply the steam to the internal mixing means 6 and/or the segments of the hollow
mantel, respectively. This steam condensates in the internal mixing means 6 and/or
in the mantel 2. This condensate is removed from the individual internal mixing means
6, when its condensate discharge pipe 8 is in a position approximately between 7 and
5 o'clock. The condensate from the mantel is discharged, when the condensate discharge
pipe 9 of the mantel is in a rotational position between 7 and 5 o'clock. In these
positions, the condensate flows from the internal mixing means 6 and from the hollow
volume in the mantel into the condensate collection pipe 7. Since the cross section
of this pipe 7 is closed at least partially at position 16, the collected fluid is
pushed upwards during the rotation of the pipe and once the discharge pipe has reached
approximately the 2 o'clock-position, the collected fluid is discharged via this pipe
7.2 to the ambient. The discharge takes place until the discharge pipe 7.2 has approximately
reached the 12 o'clock-position. During the subsequent rotation of the drum, the discharge
is repeated. A person skilled in the art understands that during one entire rotation
of drum 10, each internal mixing means 6 and each segment in the mantel 2 is emptied
from condensate only once. No pump is needed for the discharge of the condensate.
Once the condensate in the collection pipe 7 has been lifted over a certain height
in the collection pipe 7, due to the rotation of the collection pipe 7, the discharge
takes place by gravity.
[0022] Fig. 2 - 7 show construction details of the inventive mixer. As can be particularly
seen from fig. 3, in the present case, the mixer comprises a multitude, here three
internal mixing means 6, which are all hollow, so that steam can be injected into
the internal of these mixing means 6, where it condensates and thereby heats the product
to be mixed. The means 6 are fixed to the drum 10 and co-rotate with drum 10. There
are no moving parts in the drum. As can be also seen from fig. 3, the inventive mixer
comprises preferably support means 14 to support the steam inlet 12 and discharge
outlet 7.2 and/or the rotational axis of the mixer.
[0023] Fig. 4 clearly depicts that the condensate collection pipe 7 is fixed to the drum
10 and co-rotates together with the drum 10 and that the diameter of the collection
pipe 7 is larger than the outer diameter of the drum 10. This assures that when a
pipe 8 or 9 is in its discharge position, e. g. between the 7 and 5 o'clock-position,
the condensate flows downwards by gravity into the collection pipe 7. As can be particularly
seen from fig. 5, the condensate discharge pipe 8 comprises a sloped portion 8.1,
which is sloped downwards when this respective pipe 8 is in its discharge position.
This also promotes the discharge from the internal mixing means 6 into the collection
pipe 7. Fig. 5 also depicts that each internal mixing means 6 comprises a condensate
collection area 6.1. In this collection area 6.1 the condensate in the internal mixing
means 6 is collected during the rotation of drum 10. From this collection area 6.1
the condensate flows via condensate discharge pipe 8 into the condensate collection
pipe 7. The collection area 6.1 is preferably sloped towards the collection pipe 7,
to promote the outflow of the condensate.
[0024] Fig. 6 and 7 show, that steam inlet pipe 12 and condensate discharge 7.2 are at least
partially arranged concentrically. Furthermore, it can be seen that drum 10 comprises
an inspection opening 15. Particularly, from fig. 7 it can be seen that in the steam
supply pipe 12.3 a valve 13 is provided, which is open during steam supply, so that
both segments of the hollow mantel 2 are supplied with steam in parallel. In case
water is supplied to the hollow mantel, this valve is closed, so that there is only
one supply to the mantel. The two segments are now operated in series. In a preferable
embodiment, fluid guiding means, e. g. for water, are arranged between the two side
walls to improve the heat transfer between the fluid and the inner side wall of the
drum 10.
[0025] List of reference signs:
- 1
- mixer
- 2
- mantel
- 3
- first end,
- 4
- second end
- 5
- axis of rotation
- 6
- internal mixing means, scoop, shovel
- 6.1
- condensate collection area
- 7
- condensate collecting volume, condensate collection pipe
- 7.1
- ends of the condensate collecting pipe
- 7.2
- discharge of the condensate collecting pipe
- 8
- condensate discharge of the mixing means 6
- 8.1
- downward slope
- 9
- condensate discharge of the mantel
- 10
- drum
- 11
- direction of rotation
- 12
- steam inlet
- 12.1
- steam distribution pipe
- 12.2
- steam supply to internal mixing means 6
- 12.3
- steam supply to the mantel 2 of the drum 10
- 12.4
- supply from the steam inlet 12 to the distribution pipe 12.1
- 13
- valve
- 14
- support
- 15
- inspection-, cleaning-opening
- 16
- at least partial closing of the inner diameter of the pipe
1. Mixer (1) with a drum (10) that comprises a mantel (2), which is closed at both ends
(3, 4) and which rotates around an axis of rotation (5), characterized in, that the drum (10) is indirectly heated with steam and/or cooled with water and/or oil
and/or any other fluid medium.
2. Mixer according to claim 1, characterized in, that the drum (10) comprises at least one, preferably a multitude of internal mixing means
(6) and that at least one mixing means (6) and/or the mantel (2) of the drum (10)
are heated with steam and/or cooled with water and/or oil and/or any other fluid medium.
3. Mixer according to claims 1 or 2, characterized in, that the mixing means (6) are at least partially hollow and/or that the mantel (2) comprises
two spaced apart sidewalls.
4. Mixer according to one of the preceding claims, characterized in, that condensate is removed from each mixing means (6) and/or the mantel (2) via a collecting
volume, preferably a collection pipe (7) which is connected to the condensate discharge
(8) of each mixing means (6) and/or the condensate discharge (9) of the mantel (2).
5. Mixer according to claim 4, characterized in, that the collecting pipe (7) co-rotates with the drum (10).
6. Mixer according to one of claims 4 or 5, characterized in, that the collecting pipe (7) is at least partially ring shaped.
7. Mixer according to claim 6, characterized in, that the collecting pipe is closed at one location (16), preferably at one or both of
its ends (7.1).
8. Mixer according to claims 4 - 7, characterized in, that the collecting pipe (7) extends at least partially beyond the circumference of the
drum.
9. Mixer according to one of the claims 2 - 8, characterized in, that the internal mixing means (6) comprise a condensate collection area (6.1).
10. Mixer according to claim 9, characterized in, that the condensate collection area (6.1) is tilted towards the condensate discharge (8).
11. Method for heating the rotating drum (10) of a mixer (1), with steam, characterized in, that condensate is removed discontinuously.
12. Method according to claim 11 or the preamble of claim 11, characterized in, that the condensate is discharged from the mixer (1) and/or from the internal mixing means
(6) and/or from the mantel (2) by gravity.
13. Method according to one of the preceding claims or the preamble of claim 11, characterized in, that mixing means (6) and/or at least a segment of the mantel (2) of the drum is heated
with steam and that the condensate is removed discontinuously only once per rotation
from the mixer, from each mixing means (6) and/or from each segment of the mantel.