EP0517178B1 - Conical driver or mixer with swivel arm drive and sealing device - Google Patents

Abstract

A conical dryer or mixer with swivel arm drive and sealing device comprises a conical mixing vessel having an upper housing cover, in whose centre a driving device (1) is arranged in alignment with the vessel axis, which driving device drives the swivel arm (5), rotating it around the vessel axis and which further drives rotationally the mixing screw (6), which is rotatably mounted at the free, pivotable end of the swivel arm, and additionally a first sealing and lubricating assembly (3) being provided to supply the upper, housing cover-side, centre-side bearing of the swivel arm, and a second sealing and lubricating assembly (7) for supplying the swivel arm-side bearing of the mixing screw on the swivel arm. <??>In order to supply both the sealing and lubricating assemblies simultaneously, provision is made for the centre-side sealing and lubricating assembly and the swivel arm-side sealing and lubricating assembly to be connected to one another via lines (21,22), and for the two sealing assemblies to be supplied with liquid via a common stock vessel (9) situated outside the mixer. <IMAGE>

Description

The present invention relates to a cone dryer and / or mixer according to the preamble of patent claim 1.

Cone dryers or cone mixers of this type are preferably used in pharmacy, and also in the food and chemical industries.

In such cone dryers and cone mixers, there is the problem that with two different drive motors and associated gears, on the one hand, the swivel arm is driven to rotate about the container axis and, on the other hand, the mixing screw, which is arranged in the swivel arm, is rotated. It is from DE 35 08 711 A1 a cone screw mixer with a heated mixing screw, consisting of a vertical mixing container provided with a lid closure, each with a rotatable around its own axis and around the container axis and via a rotating in the container axis drivable mixing screw known, the swivel arm and the mixing screw being driven by two drive shafts arranged on the container lid and engaging in the interior of the mixer through an opening in the lid and being coaxially and rotatably mounted one inside the other. This known screw mixer each has a sealing and lubrication package at the required points, the lubrication package being supplied with lubricant via a line, but the position of the lubricant container remains defined.

The disadvantage of this dryer lies in the coaxial drive shaft guidance of the lubrication line, which causes sealing problems due to the axis rotation, so that the reliability of this conical screw mixer is questioned.

So you have a total of two bearing arrangements to be lubricated and monitored, namely on the one hand the mounting of the gear unit in the container center on the container lid and on the other hand the rotary mounting of the mixing screw in the swivel arm housing.

These bearing points are spatially separated from one another and each bearing point is associated with a lubrication arrangement for lubricating the slide rings and, if appropriate, a product blocking chamber. With the lubrication arrangement for the lubrication of the slide rings, the slide rings are intended to be in constant use during the operation of the conical screw mixer be lubricated, the lubrication arrangement must be made so that the lubricant does not penetrate into the container space and can contaminate the product. For this purpose, it is known to arrange product barrier chambers in such a way that the lubricating liquid for the slide rings cannot get into the product space.

Such arrangements are only known for agitator tanks, i.e. Containers that do not work with a swivel arm and a mixing screw rotatably driven therein.

However, as soon as you want to equip a cone dryer or a cone mixer with such a bearing and sealing arrangement, considerable difficulties arise.

It is namely extremely difficult to provide the bearing and sealing unit in the upper region of the swivel arm housing, in which the mixing screw is rotatably mounted, with a mechanical seal lubrication and a product locking chamber. After the mixing screw itself is driven to rotate and the swivel arm rotates around the container axis, the bearing arrangements are rotating and are difficult to access from the outside. So far it is only known that a storage container is arranged on the rotating swivel arm, in which the slide ring lubrication liquid is present. However, this has the disadvantage that this container must be arranged in the product space and there is therefore a risk that if the container is damaged, the sliding ring lubricating liquid will leak and contaminate the product. Likewise, an unfavorable dead space results from the arrangement of this container with the external lines. Furthermore, it is not possible to check the container arranged in the product space with regard to its lubricating liquid during the operation of the cone dryer or mixer.

In addition, it has not previously been possible to arrange a product lock chamber in the storage unit between the mixing screw and the swivel arm housing.

The present invention is therefore based on the object of developing a cone dryer or mixer of the type mentioned in such a way that the bearing and sealing arrangement can be supplied with lubricating liquid or a product blocking medium in an easily accessible and controllable manner from the outside, so that the risk of Contamination of the mixed product is minimized.

To achieve the object, the invention is characterized by the technical teaching of claim 1.

An essential feature of the present invention is that with the external reservoir there is simultaneous lubrication of the central bearing and sealing arrangement on the housing cover in connection with the sealing arrangement rotating with the swivel arm between the swivel arm and the screw.

According to the invention, a line system is therefore proposed which supplies both the central storage and sealing unit in the container center and, at the same time, the storage and sealing unit in the swivel arm housing in which the mixing screw is rotatably mounted.

The main advantage of this is that an external storage container can now be used, which simultaneously and synchronously supplies the two sealing and bearing arrangements mentioned above. For the first time, the tightness of the bearing of the swivel arm and the bearing of the mixing screw can now be monitored and guaranteed together during operation.

In a development of the present invention, it is provided that not only is there a corresponding supply of both bearing and sealing units with a mechanical seal lubrication liquid, but in addition corresponding product blocking chambers are arranged, one product blocking chamber in the central, upper sealing and bearing arrangement in the container center and another product blocking chamber in the mixing screw-side bearing and Sealing arrangement are arranged.

In this way, increased safety requirements can be taken into account, since the arrangement of such product barrier chambers in any case prevents the escape of lubricating ring lubricant in the product space. A dryer or mixer according to the invention can therefore also be used for the pharmaceutical industry or the food industry and consequently has an extremely high level of operational reliability.

According to the invention, rotary seals are used, such rotary seals being provided both in the center-side bearing and seal arrangement and in the mixing screw-side bearing and seal arrangement.

Such rotary seals ensure that the mechanical seal lubrication fluid supplies the mechanical seals. According to the invention, there is therefore a line routing for the line pairs for the supply with slide ring lubrication liquid and possibly for the supply with sealing air or sealing gas for the product blocking chambers in the swivel arm housing.

For this purpose, the line pairs are first fed into the fixed part of the central gearbox-side gear unit, in order to then be guided between rotary seals, and then at the outlet of the rotary seals via a further pair of lines on the mixing screw side Bearing and sealing arrangement to be fed. It is important that these line pairs are guided along in the swivel arm housing, which has the advantage that no external lines are arranged in the product space. Such external lines are disadvantageous because there is a risk that product will settle on these lines or, if such lines break, the liquid contained in the line will leak and contaminate the product.

It would be possible to lead such lines through the center of the central hollow shaft, which is provided in the gearbox-side gear arrangement and which is known from the applicant's earlier patents. Such a central passage of lines through this hollow shaft is disadvantageous if this hollow shaft is required for the passage of other media, e.g. to carry out a spray medium with which a spray medium is to be introduced into the product space or if one needs this central cavity for the implementation of a mixing screw heating.

The invention accordingly provides that outside of the central hollow shaft, pairs of lines are guided in the swivel arm housing in such a way that they supply both the bearing and sealing arrangement on the container lid side and the bearing and sealing arrangement on the mixing screw side. In the above description, it was assumed that a liquid was used as the sliding ring lubrication medium. It is also included in the scope of the present invention if a lubricating gas (for example a hydrogen gas) is used instead of the lubricating liquid. Likewise, in the further description it is assumed that a gas is used as the barrier medium for the product barrier chambers. Instead, a liquid can also be used in the context of the present invention.

Instead of the mechanical seals described here, which act essentially axially, one could also use radial seals instead, which is also encompassed by the present invention. In the present invention, the technical teaching is important that both the bearing center-side bearing and sealing arrangement are supplied with one and the same mechanical seal lubrication liquid, and at the same time the mixing screw-side bearing and sealing arrangement in the same line.

The subject matter of the present invention results not only from the subject matter of the individual patent claims, but also from the combination of the individual patent claims with one another. All of the information and features disclosed in the documents - including the summary -, in particular the spatial design shown in the drawings, are claimed to be essential to the invention, insofar as they are new to the prior art, individually or in combination.

In the following, the invention is explained in more detail with reference to drawings showing several possible embodiments. Here, from the drawings and their description, further features and advantages of the invention that are essential to the invention emerge.

Figur 1:

Teilansicht eines Mischer-Trockner-Apparates,

Figur 2:

schematisiert im Schnitt die geschnittenen Bereiche X und Y gemäss Figur 1,

Figur 3:

der Schwenkarm im Schnitt,

Figur 4:

Schnitt durch den Schwenkarm in Höhe der Linie A-A in Figur 3.

Figur 5:

eine weitere Ausführung der Erfindung, wobei die vorher beschriebenen axial wirkenden Gleitringdichtungen durch Radialdichtungen ersetzt sind.

Figur 6:

ein weiteres Ausführungsbeispiel im Vergleich zu Figur 4 mit einem Detailschnitt.

Show it:

Figure 1:

Partial view of a mixer-dryer apparatus,

Figure 2:

schematically in section the cut areas X and Y according to FIG. 1,

Figure 3:

the swivel arm in section,

Figure 4:

Section through the swivel arm at the level of line AA in Figure 3.

Figure 5:

a further embodiment of the invention, wherein the previously described axially acting mechanical seals are replaced by radial seals.

Figure 6:

a further embodiment in comparison to Figure 4 with a detail section.

For the sake of simplicity, only a cone dryer is assumed in the following description, although both the design as a cone dryer and as a cone mixer are claimed as essential to the invention by the present invention.

In the cone dryer mixer apparatus shown in FIG. 1, two drive motors are arranged one above the other with the associated gearboxes in the container axis 41, the exact bearing arrangement and its composition being mentioned in earlier patents by the same applicant. The disclosure of these patents will be fully encompassed by the present disclosure.

At the upper part of the gear unit 1 there is a supply container 9, which has an inlet 10 and an outlet 11.

The entire gear unit 1 is seated on the container flange 3 and is sealed and stored there by a seal package 7. On the inside of the container, a central pivot arm housing 4 is arranged in the container axis 41, which together with a connecting arm 23 results in the pivot arm 5. In the upper region of the swivel arm 5, the mixing screw 6 is rotatably sealed and supported in a seal package 8.

In Figure 2, the cable routing is shown schematically, which is then carried out constructively according to Figure 3.

First, it is pointed out that a hollow shaft 2 extends from the gear unit 1, which hollow shaft 2 drives the swivel arm 5 to rotate about the container axis 41.

In the gear unit 1, the mechanical fluid from the supply container 9 is fed via the outlet 11 into a transverse bore 18 and there it reaches the space between two inner and outer mechanical seals 16, 17 which take a radial distance from one another.

The inner mechanical seal 16 sits radially on the inside of the hollow shaft and is an additional protection that lubricant cannot enter the product space 42 from the bearing 12 downward.

In addition, a so-called safety locking chamber is provided as a further safety measure, which is essentially formed by a transverse bore 15, which is arranged between the bearing 12 and below a seal 13.

A further seal 14 is arranged below the transverse bore 15 to protect the further seals 16, 17 underneath.

Each of the mechanical seals 16, 17 consists of a fixed sliding ring, which is lubricated by the arrangement described below, and a circumferential ring, which is arranged in a transverse flange 43 of the hollow shaft 2.

The sliding ring lubrication fluid is thus via the cross bore 18 inserted into an annular channel 19 arranged in the fixed part and supplies the mechanical seals 16, 17 there.

In the peripheral part, in the area of the transverse flange 43, there is a connecting bore 20 in the area in which the mechanical fluid is collected and taken in a line, a line pair 21 being drawn in FIG. 2 for the sake of simplicity, which means that the line pair 21 consists of an inlet pipe and an outlet pipe.

This pair of lines can also be referred to as a supply and return line. For reasons of simplicity, only the feed line was shown in FIG. 2, i.e. the line flow from the storage container into the upper seal package 8 and from there into the lower seal package 7. The medium is returned in an analogous manner, which is not shown in FIG. 2 for reasons of drawing. The corresponding return lines would then be on the opposite side (as shown in FIG. 2), these return lines then opening again in the storage container 9.

To seal the mechanical seals 16, 17, a radially outer annular chamber 25 is provided, which is separated by the sealing lip 24 on the product side and which is connected to a pair of lines 28 via a longitudinal bore 27 and an associated transverse bore 26. The pair of lines 28 is connected to a container 29, only the pair of lines 28 being indicated for reasons of simplification in the drawing, which actually consists of a forward and a return line, however.

The annular chamber 25 is also detected on the rotating part (transverse flange 43 of the hollow shaft 2) in the region of the annular chamber 25 and opens there into a line pair 22, only the flow line being shown in FIG. 2 for reasons of simplification.

The mixing screw-side bearing and sealing arrangement (sealing package 7) will now be described below.

The mixing screw 6 is in this case rotatably supported by a bearing 31 in the swivel arm housing 30 and sealed by the mechanical seals 32, 33.

The annular chambers are present in the same way as were described with the aid of the sealing packs 7.

The mechanical seal lubricant is therefore supplied via the inlet line (line pair 21) via a collecting duct 38, a bore 39 leading from the collecting duct 38 to the annular chamber 34.

For reasons of simplification, it is not shown that an annular channel is again present on the rotating part of the mixing screw.

It is not shown that a return line is present from this ring channel, which in turn opens into the same ring channel that is connected to the connecting bore 20. This results in a completely closed system between the annular chambers of the upper mechanical seals 16, 17 and the annular chambers of the lower mechanical seals 32, 33.

The supply of the product blocking medium is also implemented in an analogous manner.

From the annular chamber 25, the pair of lines 22 leads the product blocking medium via a transverse bore 44 into an annular chamber 35, where the drain line is also not shown for reasons of simplification, which then returns to the upper annular chamber 25 and in turn forms a closed line system.

The structural design of the line guides is described in more detail with reference to FIG. 3.

The connecting bore 20 is embodied in the swivel arm housing 4 arranged on the center side as a longitudinal bore and merges into a transverse bore 45 which opens into a channel system 37 in which the line pairs 21, 22 are arranged. For the sake of simplicity, only one line pair is shown in FIG. 4, while the other line pair offset from the above-mentioned line pair would be recognizable in FIG. 4 by 90 °.

The channel system 37 is shown offset by 90 ° in FIG. 3 and it can be seen that the channel system 37 extends downward in the central axis of the swivel arm housing 4, is then angled by an angle of approximately more than 90 ° and is guided along in the connecting arm 23 is where the line system 37 is in turn angled, in order then to be guided parallel to the axis 46 of the mixing screw into the sealing package 7 below.

It is important that the entire duct system with the line pairs 21, 22 is guided outside on the swivel arm housing 4 and also along the outside on the connecting arm 23 in order to get into the sealing package 7 from there.

With the present invention, the advantage is thus achieved that there are no external lines that cut through the product space, and instead these lines are designed as welded profile 47, such a pair of profiles being shown in FIG. 4 and a pair of lines, for example the pair of lines 21, symbolizes.

The design of the profile 47 can vary depending on the application, either a triangular profile can be used, as shown in FIG. 4, or a semicircular profile or other geometric shapes.

FIG. 5 shows a section similar to that shown in FIG. 2, only the central seal pack 8 being shown in FIG. 5 and showing that the seals described above are replaced by other seals.

Otherwise, the same reference parts apply to the same parts.

The mechanical seals 16, 17, which are described in FIG. 2, are now replaced by corresponding radially acting seals 16a, 17a.

Figure 6 shows that the profile 47 can not only be used as a channel for guiding a medium, but that a partition 48 is present in the area of this profile, so that there are two separate line sections in the profile 47, the sliding ring in one line section -Lubrication liquid can be guided and in the other line section the medium for the product barrier chamber.

DRAWING LEGEND

1

Gear unit

2nd

Hollow shaft

3rd

Container flange

4th

Swivel arm housing (center)

5

Swivel arm

6

Mixing screw

7

Seal package

8th

Seal package

9

Storage container

10th

Intake

11

Finish

12th

camp

13

poetry

14

poetry

15

Cross hole

16

inner mechanical seal

17th

outer mechanical seal

18th

Cross hole

19th

Ring chamber

20th

Connecting hole

21

Line pair

22

Line pair

23

Connecting arm

24th

Sealing lip

25th

Ring chamber

26

Cross hole

27

Longitudinal bore

28

Line pair

29

container

30th

Swivel arm housing

31

camp

32

inner mechanical seal

33

outer mechanical seal

34

Ring chamber (mechanical seal)

35

Annulus (product lockout)

36

drilling

37

Channel system

38

Collecting channel

39

drilling

40

Sealing lip

41

Container axis

42

Product space

42

Cross flange

44

Cross hole

45

Cross hole

46

axis

47

profile

48

partition wall

Claims (5)

1. A conical drier or mixer with swivel arm drive and sealing arrangement, consisting of a conical mixing vessel with an upper housing cover, in the centre of which, in alignment with the container axis (41) a drive arrangement (1) is arranged, which drives the swivel arm (5) in a rotating manner around the vessel axis (41) and which in addition drives in a rotating manner the mixing screw (6) which is rotatably mounted on the free, swivellable end of the swivel arm (5), in which a first sealing- and lubricating set (8) is provided to supply the upper mounting, on the centre side, of the swivel arm (5), and also a second sealing- and lubricating set (7) to supply the mounting, on the swivel arm side, of the mixing screw (6) on the swivel arm (5), characterised in that outside the mixer a collecting vessel (9) is arranged, from which slide ring seals (16, 17) of the sealing- and lubricating set (8) on the centre side and corresponding slide ring seals (32, 33) of the sealing- and lubricating set (7) on the swivel arm side are supplied jointly with lubricating fluid, and outside the mixer a further vessel (29) is arranged from which a product shut-off chamber of the sealing- and lubricating set (8) on the centre side and a corresponding product shut-off chamber of the sealing- and lubricating set (7) on the swivel arm side are jointly supplied with a product shut-off medium, in which the two sealing sets (8, 7) are connected with each other in each case by means of a pair of ducts (21) for the lubricating fluid, and of a pair of ducts (22) consisting of an inlet duct and an outlet duct for the product shut-off medium, in which the pairs of ducts (21, 22) are guided externally along the swivel arm housing (4) and connecting arm (23).
2. A conical drier or mixer according to Claim 1, characterised in that the ducts (21, 22) are constructed as a hollow section (47) which are secured on the outer periphery of the swivel arm (4, 5).
3. A conical drier or mixer according to one of Claims 1 or 2, characterised in that the slide ring seals (16,17; 32,33) consist of axially directed slide rings arranged in pairs on the rotating and on the fixed part.
4. A cone drier or mixer according to one of Claims 1 - 3, characterised in that the slide ring seals (16,17; 32,33) arranged in pairs form rotary seals in which the lubricating fluid is introduced into the intermediate space between two fixed slide ring seals (16,17; 32,33) spaced radially apart from each other, into the region of an annular chamber (19,34) and is collected and drawn off in the intermediate space between the pairs of slide rings arranged in the rotating part in the region of a connecting bore (20).
5. A cone drier and mixer according to one of Claims 1-4, characterised in that the sealing sets (7,8) are connected with each other by means of a closed lubricating circuit consisting of a forward line and return line, and that the closed circuit is supplied by a forward vessel (9) lying outside.

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