EP1909051A1 - Drum or drum segment for a drying apparatus for bulk material and process for manufacturing a drum or drum segment. - Google Patents

Abstract

The drum (5) or drum segment has fixtures arranged in an inner side of the drum, which is rotatable around a middle axis. The fixtures mix and convey fluid materials when a temperature-controlled gaseous transfer fluid is conducted from a drum inlet to a drum outlet. Statically load-bearing support rings (7) elastically compensate tensile and compressive stresses and are positively and/or non-positively connected to the fixtures and/or a mounting frame (14), where the rings are arranged between the fixtures and the drum. An independent claim is also included for a method for manufacturing a drum or a drum segment for a drying system.

Description

The invention relates to a drum or drum segment for a drying device of pourable material according to the preamble of claim 1. Further, the invention relates to a method for producing a drum or a drum segment for a drying apparatus according to the preamble of claim 11.

Rotary drums are used in the processing industry for the drying of wood chips or other cellulosic material. The material to be dried and a heated gas are introduced at the entrance of the rotary drum and the dried material and the gas are discharged at the outlet. Decisive for a good dryer effect is that the material in regular contact with the heated gas occurs and optimum heat transfer can be achieved. The material to be dried is passed by mechanical and / or pneumatic transport through a rotating drum made of sheet steel.

In addition, internals are usually provided in the drum, which provide during the rotation of the drum in the sense of a mixer for a thorough mixing of the material. The internals are either held in uprights or welded directly to the drum wall or screwed. So-called cross fittings are preferably used in the industry, which in addition to a proper mixing and the free-flowing or pourable Good lifted at short intervals, transported upwards and then trickle in the further course of rotation from top to bottom through the drum. Furthermore, the cross fittings immersed in the material lying at the bottom of the drum during rotation destroy stalls or accumulations of the material and provide uniform heating in the material. Crosses are for example from the DE 23 62 725 B2 known. From the DE 196 31 998 C1 On the other hand, it is known to install radial installations starting from the circumference of the drum in the direction of the drum center.

Although not described in detail, the person skilled in the art is aware and aware that these installations are fixed by welding and / or screwing. Depending on requirements, support structures may be used under certain circumstances or an inner pipe may be additionally installed to ensure the necessary stability of the installations during operation. To improve the stability of the drum reinforcing rings can be mounted inside, outside or integrated in the drum shell depending on the application. The outer reinforcing rings have the advantage that these can serve as so-called races and also as bearings for the entire drum. The drive is usually done with sprocket, chain or friction belt drives. During the design, construction and installation of drum dryers, an optimized heat transfer from the hot gas to the material to be dried is necessary by appropriate selection and arrangement of internals. It is crucial that local areas, which are likely to cause congestion of the material are to be avoided. Otherwise, the material in the drum may ignite due to excessive temperature. Due to the high temperatures in operation, it is also important to design and manufacture the drum so that the recording and the compensation of thermal stresses due to different temperature and different expansion behavior of the internals, the drum shell and possibly the reinforcing rings is given. It is also necessary to ensure proper absorption and compensation of the stresses caused by the dead weight and the dynamically moving drum and their twisting.

In order to compensate for the stresses occurring during operation, especially during the heating and the promotion of the material, it has been customary in terms of design to mount the entire construction on sliding pieces, joints and / or spring units in the case of rigid installations. But all these technical installations have an increase in the weight of the drum and possibly even a certain imbalance result. In addition, results the problem that the material to be dried is highly adhesive and preferably accumulates in such places and hinders or even prevents the function of the sliding pieces, the joints and / or the spring unit after a few operating units. The serious consequence is that damage to the drum dryer itself occurs.

The probability of error is also highly dependent on the way of installation. This is usually done by the introduction and assembly of items during production in the factory or at the future site on the site. In order to avoid predicaments during the assembly of the items, which takes place inside the drum, the rotation of the drum is regularly required for this, which in turn leads to a change in the voltages occurring. For reasons of safety at work, it is absolutely necessary to completely clear the entire drum before each rotation. This includes not only the personnel, but also the manufacturing equipment (welding equipment), tools and loose material. A parallel and actually meaningful execution of the assembly work in several places is hardly possible in practice due to this regularly performed drum movement and the exhaust gases occurring during welding. This has - depending on the number of parts of the internals - serious consequences for the duration and thus the cost of assembly, as with each rotation of the drum an immense clean-up and hedging process goes hand in hand.

The invention has now the object to provide a drum or a drum segment that allows optimal self-compensation with respect to the stresses occurring in the construction of the internals and the drum during assembly and operation and does not have the disadvantages of the prior art and further to provide a method for producing a drum or a drum segment, which avoids the above-mentioned disadvantages of the prior art and allows a simple and low-tension mounting of the internals in the drum.

The task with respect to a drum or a drum segment is achieved in that a plurality of support rings are arranged between the internals and the wall of the drum, which are carried out statically stable, but still compensate tensile and compressive stresses elastically and positively and / or non-positively with the internals and / or the support frame and the drum are connected.

The object of the method is achieved by the production of a built-in module by mounting internals between two support frames, which further tensile and compressive stresses elastically receiving metallic support rings are mounted on all sides of the module so that they face outward, and the built-in module with the Support rings is introduced into a drum or a drum segment and preliminarily pre-fixed by means of wedges and / or tack welding, wherein then the elastic support rings of the built-in module with the drum or a drum segment force and / or positively connected.

The drum according to the invention or the drum segment is for drying wood chips, chips or similar chip material, especially for so-called flakes or strands in the production of OSB (English: oriented strand board - plate of aligned chips), but also for drying of other flowable or pourable material suitable.

1. a) die Stabilität der Trommel zu gewährleisten;
2. b) die Aufnahme von Spannungen ohne fehlerträchtige Schiebestücke, Gelenke oder Federn zu gewährleisten;
3. c) flexible Befestigungspunkte für die eigentlichen Einbauten (z. B. Kreuzeinbauten) zur Verfügung zu stellen;
4. d) den Transport des Materials durch die Trommel im Trocknungsbetrieb durch einen vergleichsweise sehr hohen freibleibenden Trommelquerschnitt zu begünstigen;
5. e) eine Montage ganzer Module fertiger Ständer mit Einbauten außerhalb der Trommel zu ermöglichen und
6. f) die Fehlerhäufigkeit und die Montagedauer deutlich zu reduzieren

The unilaterally open support rings are particularly suitable

1. a) to ensure the stability of the drum;
2. b) to ensure the absorption of stresses without error-prone sliding pieces, joints or springs;
3. c) provide flexible attachment points for the actual installations (eg cross installations);
4. d) to promote the transport of the material through the drum in the drying operation by a comparatively very high remaining free drum cross-section;
5. e) to allow assembly of complete modules finished stands with internals outside the drum and
6. f) significantly reduce the error frequency and the installation time

In a preferred embodiment, the unilaterally open support rings are provided with feet on the open side of the support ring, resulting in an "omega-shaped" (Ω) appearance of the support ring. Detached from the arrangement of the individual struts or the cross fittings, the connection to the drum shell is carried out via a plurality of omega-shaped support rings. The one hand, rigid, but static yet voltage-tolerant construction makes it possible outside the actual drum, the fixtures section ready to assemble (weld, screw) and bring in sections. The type and amount of installed between two omega support plates internals (crosses, blades, etc.) depends on the application, for example, the throughput and the material to be dried. Inside the drum, only the actual connection with the drum shell has to be made via the omega feet. Working in a predicament and / or turning the drum during assembly is eliminated. The design of the struts within the omega support disk is statically optimized and also application-dependent. Compared to other solutions, a relatively large proportion of the drum cross-section remains open, whereby the material transport favors and deposits are largely avoided. Starting from the middle of the drum can be easily mounted parallel to both ends, with the usually provided anyway cleaning doors are used as entry and exit. Also possible is the complete pre-assembly off the construction site and a pre-assembly of whole Drum dryer segments (drum casing and internals fully assembled in, for example, 3 or 4 m axial lengths). In this case, the individual segments which already have the finished internals are welded together by joining the drum shell to the actual drum dryer. A necessary installation of fixtures on the site itself can then be completely eliminated.

Preferably, the feet of the Omega-shaped support rings are connected to the drum, of course, a rotated arrangement is conceivable and the bulbous bulges of the support rings are connected to the drum, with welding and / or screw connections come to the arrangement. However, plug-in systems for the complete installation segment are also conceivable. In a further embodiment, the flow width of the support rings in the flow direction of the drum is approximately equal to the flow width of the internals. In a preferred embodiment, the internals are arranged between two circular support frames, the circular support frames having a smaller radius than the drum radius and the support rings being arranged between the support frame and the drum.

Drum or drum segment according to one or more of claims 1 to 7, characterized in that to avoid high air resistance, the support rings are arranged in the flow direction.

Further advantageous measures and embodiments of the subject matter of the invention will become apparent from the dependent claims and the following description with the drawing.

Figur 1

eine schematische Darstellung einer Trocknungsanlage mit einer erfindungsgemäßen Trommel bzw. mehrerer Trommelsegmente,

Figur 2

einen Schnitt durch eine Trommel nach Figur 1 zur Darstellung des Stützgestells mit den Stützringen,

Figur 3

den Schnitt nach Figur 2 mit zusätzlicher Einzeichnung der Einbauten an dem Stützgestell,

Figur 4

eine vergrößerte Seitenansicht einer Trommel nach Figur 1 mit einem Teilriss mit darin enthaltener Darstellung der Einbautenmodule und

Figur 5

eine Darstellung des erfindungsgemäßen Verfahrens zum Montage von Einbautenmodulen in eine Trommel.

Show it:

FIG. 1

a schematic representation of a drying plant with a drum according to the invention or a plurality of drum segments,

FIG. 2

1 a section through a drum according to FIG. 1 to show the support frame with the support rings;

FIG. 3

the section of Figure 2 with additional marking of the internals to the support frame,

FIG. 4

an enlarged side view of a drum of Figure 1 with a partial section with therein contained representation of the built-in modules and

FIG. 5

an illustration of the method according to the invention for the assembly of built-in modules in a drum.

In Figure 1, a system for drying flowable material 9 is shown schematically. As a rule, when using a rotatable drum 5, gas is heated in a combustion chamber 1 and fed to a mixing chamber 2. In the mixing chamber 2, material 9 is added via an inlet lock 3 and via the flow in the direction of the drum 5 for Drum inlet 4 transported. In the drum 5, the material is finally mixed and subjected to uniform heating and drying. After the material 9 leaves the drum outlet 6, it is usually fed to the pipe connection 13 (not shown) with a rotary valve (not shown) and further treatments or production. Moreover, the drum 5 is provided with races 10 to which a drive 11 can attack. In the context of an illustrated embodiment, the drum 5 may consist of a plurality of drum segments 12 and attached drum inlet 4 and drum exit 6. This may have manufacturing or assembly reasons; it is preferably conceivable for drum segments 12, 12 ', 12 "... to be produced, which are assembled at the assembly location to form a drum 5. It is of course possible for the running rings 10 to be arranged at different locations on the drum 5 than here It should be noted that depending on installation effort and possibility, the necessary built-in modules 18 are either supplied separately from the drum segments 12 and assembled on site, or the built-in modules 18 are already used immediately after their installation in a drum segment 12.

In Figure 2, the section AA is shown in Figure 1, in which the interior of a drum 5 or a drum segment 12 is illustrated. It can be seen how a support frame 14 by the support rings 7 elastic, but static load-bearing, is held in position and position. In Figure 3 is now to Clarification of the difference, the fittings 8 in addition to the support frame 14 and the support rings 7 shown. The baffles 8 now provide the opportunity to ensure optimum mixing and distribution of the material 9 in the drum 5.

In a preferred embodiment, the unilaterally open support rings 7 feet 19 on the side of the opening 15, which give the support ring 7 an omega-shaped appearance. For the purposes of the invention, the support ring 7 can now compensate for tensile and compressive stresses resulting from the temperature difference between the assembly and operating conditions via the legs 16, which can elastically deform as required. As a result, in an optimal and above all simple way to reduce stress and the overall construction (internals 8, the support frame 14 in conjunction with the drum 5) takes during operation or state changes during operation no harm.

In this case, the application decides whether the support rings 7 in the flow direction (not shown) are arranged, or oppose with their broadside a similar resistance of the flow as the internals 8 and / or the support frames 14. The application also determines the nature of the fixtures 8. Im present example cross-shaped baffles 8 are provided, but of course there are a variety of variations. In Figure 4, the construction of a drum 5 is again represented by a partial section. For this purpose, it can be seen in partial section that several built-in module 18, 18 '... side by side in the longitudinal direction of the drum 5 are installed. In this case, as already described, a drum 5 can also consist of several drum segments 12 which have been assembled on site. The support frames 14 with the support rings 7 thereby form the boundary of a built-in module 18. In a preferred embodiment, the maintenance openings (manholes) are arranged exactly between two built-in modules 18, to give a maintenance technician the opportunity without problems to get into the interior of the drum 5. As can be seen from FIG. 3, the built-in components 8 of a built-in module 18 extend close to the wall of the drum, so that there would be no room for a service technician here.

In synopsis of the method according to the invention (FIG. 5), when a drum 5 for a dryer is produced, an installation module 18 is first assembled from the installations 8 and two support frames. This may advantageously take place outside the drum 5 itself, with the increased access space created thereby allowing several workers to work simultaneously on an installation module 18. At the same time or successively, the support rings 7 are welded. Finally, the entire built-in module 18 by means such as cranes or forklift in a drum 5, or a drum segment 12, lifted and mounted there during final assembly to the drum 5 and a drum segment 12, respectively. Advantageously, eliminates the need during assembly of such a built-in module 18, the need to rotate the drum 5 or the drum segment 12 regularly so sequentially the Connecting support frames to the drum. By inserting a complete built-in module 18 in the drum 5 or the drum segment 12, it is only necessary provisionally to fix the built-in module 18 with wedges or tack welds before the correct connection means, welding or screwing, are attached. The disadvantages of a necessary rotation of the drum during assembly or the tedious and cumbersome and cramped installation of the fixtures in a drum no longer have to be accepted.

In summary, it should be noted that the solutions presented by no means limit the spirit of the invention, but in the spirit of the invention, a variety of ways are known to the expert how the support rings could be performed to allow an elastic voltage pickup in supporting function of the internals.

List of Reference Numerals: DP1333EP

1.

combustion chamber

Second

mixing chamber

Third

input lock

4th

drum input

5th

drum

6th

drum exit

7th

support ring

8th.

fixtures

9th

material

10th

race

11th

drive

12th

drum segments

13th

pipe connection

14th

support stand

15th

opening

16th

leg

17th

maintenance openings

18th

internals modules

19th

feet

Claims (16)

Drum (5) or drum segment (12, 12 ', 12 ") for a device for pouring loose material, wherein inside the rotatable about its central axis drum (5) internals (8) are arranged, the pourable material (9) during the passage a tempered gaseous transport fluid from the drum inlet (4) to the drum outlet (6) mix and transport, characterized in that
between the internals (8) and the drum (5) a plurality of support rings (7) are arranged, the a) have a static load capacity, b) but elastically compensate tensile and compressive stresses and c) are positively and / or non-positively connected to the internals (8) and / or the support frame (14) and the drum (5). Drum or drum segment according to claim 1, characterized in that the support rings (7) open on one side are executed. Drum or drum segment according to claim 1 or 2, characterized in that the support rings (7) have a floor plan in the form of an omega "Ω". Drum or drum segment according to claim 2, characterized in that the feet (19) of the support rings (7) are connected to the drum (5). Drum or drum segment according to claim 2, characterized in that the bulbous bulges of the support rings (7) are connected to the drum (5). Drum or drum segment according to one or more of claims 1 to 5, characterized in that between the support rings (7) and the support frame (14) of the internals (8) or between the support rings (7) and the drum (5) welded joints and / or screw connections are arranged. Drum or drum segment according to one or more of claims 1 to 6, characterized in that the Incoming flow width of the support rings (7) in the flow direction of the drum (5) in approximately the flow width of the internals (8) and / or the support frame (14) corresponds. Drum or drum segment according to one or more of claims 1 to 7, characterized in that the internals (8) between two support frames (14) are arranged, wherein the circular support frames (14) have a smaller radius than the radius of the drum (5). and that the support rings (7) between the support frame (14) and the drum (15) are arranged. Drum or drum segment according to one or more of claims 1 to 8, characterized in that to avoid high air resistance, the support rings (7) are arranged in the flow direction. Drum or drum segment according to one or more of claims 1 to 9, characterized in that in each case a maintenance opening (17) between two built-in modules (18) is arranged. Method for producing a drum (5) or a drum segment (12) for a drying device of pourable material, within the rotatable around its central axis drum (5) baffles (8) are arranged, which mix and transport the pourable material (9) while passing a temperature-controlled gaseous transport fluid from the drum entrance (4) to the drum-out (6) in by the following process steps: 11.1 for the production of a built-in module (18), the internals (8) are mounted between two supporting frames (14), 11.2 tensile and compressive stresses elastically receiving metal support rings (7) are mounted on all sides on the installation module (18) so that they face outwards, 11.3 the built-in module (18) with the support rings (7) is introduced into a drum (5) or a drum segment (12) and provisionally pre-fixed by means of wedges and / or tack welding, 11.4 the elastic support rings (7) of the built-in module (18) are positively and / or positively connected to the drum (5) or a drum segment (12). A method according to claim 11, characterized in that in the production of drum segments (12) these are assembled on site to form a drum (5). Method according to one or more of claims 11 to 12, characterized in that unilaterally open support rings (7) are used. Method according to one or more of claims 11 to 13, characterized in that omega-shaped "Ω" support rings are used. Method according to one or more of claims 11 to 14, characterized in that the support rings (7) are welded. Method according to one or more of claims 11 to 15, characterized in that the support rings (7) are screwed.

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