EP0716675A1 - Rotary heating chamber for waste with internal tubing - Google Patents

Abstract

A low-temperature carbonization drum for waste includes many heating tubes located in the interior. The tubes are each secured by one end to a first end plate and by the other end to a second end plate. At least one support location for supporting the heating tubes is provided between the two end plates to prevent them from sagging. Each support location is divided into at least two spaced-apart partial supports, each with one bracket configuration. Each bracket configuration includes a plurality of support brackets that are located in the same plane as one another. The support brackets are located one after another (are staggered) and are rotationally offset from one another. As a result, the solid material in the waste can be transported largely unimpeded past the support locations.

Description

description

Pipe, rotatable heater for waste

The invention relates to a heating chamber for solid material which can be rotated about its longitudinal direction, in particular to a smoldering drum for waste, with a number of heating pipes located in the interior, each with one end on a first end plate and the other end on one second end plate are attached.

The heating chamber is used in particular as a smoldering drum for waste for the purpose of thermal waste disposal, preferably according to the smoldering-burning method.

The so-called smoldering-burning method has become known in the field of waste disposal. The method and a plant for thermal waste disposal operating according to it are described, for example, in EP-A-0 302 310. The essential components of the plant for thermal waste disposal using the smoldering process include a smoldering chamber (pyrolysis reactor) and a high-temperature combustion chamber. The smoldering chamber converts the waste fed in via a waste transport device into smoldering gases and pyrolysis residues. The carbonization gases and the pyrolysis residues are then fed to the burner of the high-temperature combustion chamber after suitable processing. Molten slag is produced in the high-temperature combustion chamber, which is removed via a fume hood and which, after cooling, is in a glass-like form. The resulting flue gas is fed to a chimney as an outlet via a flue gas line. In this flue gas line, in particular, a waste heat generator as a cooling device, a dust filter system and a flue gas cleaning system are installed. Such a plant has been widely recognized ("Stuttgarter Zeitung" from August 18, 1993, article with the headline "Smoldering process brings recycling record"). As a smoldering chamber (pyrolysis reactor), a rotating, relatively long smoldering drum is generally used, which has a large number of parallel heating pipes on the inside, on which the waste is largely heated in the absence of air. The smoldering drum rotates about its longitudinal axis. The longitudinal axis is preferably slightly inclined with respect to the horizontal, so that the solid carbonization material collects at the outlet of the carbonization drum and can be discharged from there via a discharge pipe. When turning, the waste is lifted up through the heating pipes and falls down again. As a result of this and through subsequent waste, the transport of the solid material (dust, lumps of carbon (coke), stones, bottles, metal, ceramic parts, etc.) is carried out in the direction of the discharge opening of the carbonization drum.

It has now been shown that for reasons of profitability, but also for reasons of sufficient pyrolysis and high throughput, the smoldering drum should be built relatively long. This means that the heating pipes lying in the interior must also have a corresponding length. Depending on the material of these heating tubes and their length, it can now occur that they sag in the interior, unless remedial action is taken. During the rotary movement of the smoldering drum, this leads to alternating loads, so that there can be a risk that the heating pipes will be torn out of their end holder. Such a danger can exist in particular in the case of heating pipes which are 20 to 30 meters long or even more.

The invention is based on the consideration that at least one simple support point, but preferably at least two support points in the interior, should be provided for supporting the heating pipes. Such a support point is in the form of a bracket or

Pipe penetration can be carried out. But this inevitably means that the free cross-section at the support point, which is necessary for the passage of the solid material and the carbonization gas is reduced. As a result, the transport of the solid material and the carbonization gases - possibly significant - is prevented.

The object of the invention is therefore to design a heating chamber for solid material of the type mentioned that can be rotated about its longitudinal direction in such a way that the heating pipes are supported without significantly impairing the passage of the solid material and the carbonization gases.

According to the invention, this object is achieved in that at least one support point for supporting the heating pipes is provided between the end plates, at which support point at least n = 2 longitudinally spaced support brackets are provided, which are fastened to the inner wall and in each case one support different group of heating pipes.

This can also be expressed as follows: seen in the longitudinal direction of the heating chamber there is at least one support point which is divided into at least two partial support points. At each of these partial support points, at least one support bracket for a group of heating pipes is arranged, and the support brackets of the first partial support point are rotationally offset and staggered (spaced) from the support brackets of the second partial support point, so that there is sufficient space for transporting the Solid matter and the smoldering gases remain.

A particularly preferred embodiment of the heating chamber is accordingly characterized in that each support point is subdivided into p> 2 spaced partial supports, each with a console arrangement, each console arrangement comprising a plurality of support consoles lying in the same plane. Further advantageous refinements are characterized in the subclaims. Embodiments of the invention are explained in more detail below with reference to 9 figures. The same or corresponding components are provided with the same reference numerals. Show it:

Figure 1 shows a smoldering plant with a smoldering chamber for waste, which can be used in the smoldering process, in a basic sectional representation;

2 shows a view in the direction VV of a first predetermined configuration of heating pipes in the smoldering drum of FIG. 1 with assignment of groups of heating pipes to fuel arrangements I, II and III, where p = 3 applies, and the individual support brackets are omitted;

FIG. 3 shows a view of the console arrangement I of FIG. 2;

FIG. 4 shows a view of the console arrangement II from FIG. 2;

Figure 5 is a view of the console arrangement III of Figure 2;

Figure 6 is a view corresponding to Figure 2 of a second configuration of heating pipes, where p = 3 applies;

Figure 7 shows a third configuration corresponding to Figure 2, with p = 2;

Figure 8 shows a fourth configuration corresponding to Figure 2, where p = 4 applies; and

Figure 9 shows a heating tube attachment in a support bracket. According to FIG. 1, solid waste A is introduced centrally into a pyrolysis reactor or a smoldering chamber 8 via a feed or feed device 2 and a screw 4, which is driven by a motor 6 and is arranged in a feed tube 7. In the exemplary embodiment, the smoldering chamber 8 is an internally heatable smoldering or pyrolysis drum which can be rotated about its longitudinal axis 10 and which can have a length of 15 to 30 m, which operates at 300 to 600 ° C., which is operated largely with the exclusion of oxygen and which, in addition to volatile smoldering gas s produces a largely solid pyrolysis residue. This is an inner-tube carbonization drum 8 with a multiplicity (for example 50 to 200) of heating tubes 12 aligned parallel to one another, of which only four are shown in FIG. 1 and are arranged in the interior 13. At the right or "hot" end there is an inlet for heating gas h in the form of a resting, sealed heating gas inlet chamber 14, and at the left or "cold" end there is an outlet for the heating gas h in the form of a resting, sealed heating gas inlet. Outlet chamber 16 arranged. The longitudinal axis 10 of the smoldering drum 8 is preferably inclined with respect to the horizontal, so that the outlet at the "hot" end on the right is lower than the inlet for waste A shown on the left.

A discharge device 18 is connected downstream of the pyrolysis drum 8 on the output or discharge side via a rotating central discharge tube 17, said discharge device being provided with a carbonization gas discharge nozzle 20 for the discharge of the carbonization gas and with a pyrolysis residue outlet 22 for the discharge of the solid pyrolyzation residue f is provided. A carbonization line connected to the carbonization gas outlet 20 can be connected to the burner of a high-temperature combustion chamber.

The rotary movement of the smoldering drum 8 about its longitudinal axis 10 is brought about by a drive 24 in the form of a gear which is connected to a motor 26. The drive means 24, 26 work, for example, on a toothed ring which is connected to the catch the smoldering drum 8 is attached. The bearings of the smoldering drum 8 are designated 27.

From Figure 1 it is clear that the heating tubes 12 are each fixed at one end to a first end plate 28 and at the other end to a second end plate 30. The attachment to the end plates 28, 30 is such that there is preferably an easy interchangeability of the heating tubes 12. The end of the heating pipes 12 projects through an opening from the interior 13 to the left into the outlet chamber 16 or to the right into the inlet chamber 14. The axis of the heating tubes 12 is oriented perpendicular to the surface of the end plates 28, 30. In the construction shown, it is noted that the individual heating tubes 12 are subjected to high thermal and mechanical stresses, and that the end plates 28, 30, which could also be referred to as tube plates or drum tube sheets, rotate along the longitudinal axis 10 of the carbonization drum 8.

It is important that two support points X, Y are provided between the end plates 28, 30 to support the (otherwise sagging) heating pipes 12. Seen in the direction of transport of waste A, the first support point X is one third (1/3 1) and the second support point Y is two thirds (2/3 1) of the total length 1 of

Smoldering drum 8. It is also important that each support point X, Y is subdivided into p = 3 partial supports spaced apart from each other, to which a bracket arrangement I, II or III is assigned. The distance a can be, for example, a = 1 m. Each of the console arrangements I, II, III (compare FIGS. 3 to 5) contains a plurality of support or support consoles located in the same plane in the form of rounded perforated plates made of metal, for example made of steel. These are designated in FIGS. 3 to 5 with the reference symbols la, Ib, Ic, Id and Ha, Ilb, IIc, Ild and purple, Illb, IIIc and Illd. In other words: The first console arrangement I according to FIG. like spaced apart from one another on the inner wall 33, preferably welded, preferably welded, support brackets la, Ib, Ic and Id. The two support brackets la, Ic and Ib, Id each have the same configuration (rounded off on the outside) in pairs. As stated, these are in particular metal plates provided with holes. Accordingly, the second bracket arrangement II according to FIG. 4 has the support brackets Ha, Ilb, IIc and Ild which are rotatably offset in the same plane. Here, too, two opposite support brackets Ha, IIc and Ilb, Ild each have the same rounded configuration. And accordingly, according to FIG. 5, the third bracket arrangement III comprises the four support brackets lilac, Illb, IIIc and Illd lying in one plane, rotatably offset from one another and spaced apart. In the case of the third console arrangement III according to FIG. 5, the two support brackets purple, IIIc and Illb, Illd respectively, which are fastened opposite each other on the inner wall 33, are designed in the same way.

It should be emphasized once again: the level of

Support brackets la to Id of Figure 3 is offset from the plane of the support brackets Ha to Ild of Figure 4 by the distance a in the longitudinal direction. The same applies to the level of the support brackets purple to Illd according to Figure 5; here too the distance is again a.

The heating tubes 12 can be arranged in a configuration as shown in FIG. 2 and in FIGS. 3 to 5. Then there are a plurality of peripherally arranged heating tubes 12 and a plurality of heating tubes 12 arranged approximately radially (along curved lines) for heating the more centrally located waste. The curvature depends on the rotation of the smoldering drum 8, which is indicated by an arrow 35.

In FIG. 2 it is assumed that all heating pipes 12 at a support point X or Y are replaced by a single one (dashed

4 configuration for the console arrangement III and the fastening configuration of FIG. 5 would apply to the console arrangement II.

According to FIG. 6, p = 3 spaced partial supports are again provided at each support point X, Y. Each console arrangement I, II and III in turn comprises four support consoles la to Id, Ha to Ild and lilac to Illd, respectively, lying in the same plane. Here, however, a different configuration of the heating tubes 12 is selected than in Figure 2. In the present case, six radially adjacent heating tubes 12, three adjacent to one another on the circumference, three radially adjacent to one another and then again three distributed around the circumference, etc. follow one another. In the present case, the view VV (see FIG. 1) again shows the arrangement of all ¬ cher heating tubes 12 and support brackets la to Illd, which are each assigned to groups of these heating tubes 12. Support brackets that are adjacent in the circumferential direction also have a different outer circumference here. The support brackets la to Illd are square here. It is noteworthy that - seen in the direction of rotation of arrow 35 - the support bracket la is followed by the purple support bracket and this is followed by the support bracket Ha. This means that between the two console arrangements I and II waste A has a considerable amount of free space for passage. Here, too, it becomes clear that the area projected according to the viewing direction V-V on each partial support has lost relatively little of its transport performance by introducing the individual support brackets Ia to Illd. Here, too, there is a large free cross section, and the waste A in the form of the solid f and the carbonization gases s can, so to speak, "snake through" at the support point X divided into the partial supports and also at the support point Y.

In the result, the same also applies to the embodiment according to FIG. 7. Here, only p = 2 spaced partial supports per support point X and Y are provided. The configuration of the

there is an inadmissible bending of the heating tubes 12 due to the weight of these heating tubes 12 and the waste A lying thereon. In order to ensure transport without backwater, each support point X and Y is staggered. In the preferred exemplary embodiment, each support point X, Y has a group of three console arrangements I, II, III. This staggering keeps the resistance, which opposes the transport of the waste in the heating drum 12, within reasonable limits.

Claims

claims 1. Around its longitudinal direction (10) rotatable heating chamber for solid material, in particular smoldering drum (8) for waste (A), with a number of heating pipes (12) located in the interior (13), each with one end at one first end plate (28) and with the other end to a second end plate (30), characterized in that between the end plates (28, 30) at least one support point (X, Y) for supporting the heating pipes (12) is provided, at this support point (X, Y) at least n = 2 support brackets (eg Ia, Ha ff.) spaced in the longitudinal direction (10) are provided, which are fastened to the inner wall (33) and each support a different group of heating pipes (12). 2. Heating chamber according to claim 1, so that the support brackets (Ia, Ib, Ic, Id to IVa, IVb) consist of steel and are welded to the inner wall (33). 3. Heating chamber according to claim 1 or 2, characterized in that the heating tubes (12) are each 15 to 30 m long, and that between the two end plates (28, 30) depending on the length (1) of the heating tubes (12 ) one to two support points (X, Y) are provided, which are preferably arranged approximately at a distance of half to a third of the total length (1) in front of the associated end plate (28, 30). 4. Heating chamber according to one of claims 1 to 3, characterized in that the support bracket (Ia, Ib, Ic, Id, Ha, Ilb, IIc, Ild, lilac, Illb, IIIc, Illd, IVa, IVb) supports such group Includes heating tube (12) which are arranged in an approximately radial or curved row parallel to each other. 5. Heating chamber according to one of claims 1 to 4, d a d u r c h g e k e n n z e i c h n e t that the support bracket (Ia to IVb) supported group comprises heating tubes (12) which are arranged parallel to each other in the circumferential direction near the inner wall (33). 6. Heating chamber according to one of claims 1 to 5, so that the distance (a) of the spaced support brackets (Ia to IVb) at a support point (X, Y) is approximately 1 m. 7. Heating chamber according to one of claims 1 to 6, that the supporting brackets (Ia to IVb) have a rounded circumference. 8. Heating chamber according to one of claims 1 to 7, d a d u r c h g e k e n n z e i c h n e t that the Heiz¬ tubes (12) in bushings (39), which are housed in holes (38) of the support brackets (Ia to IVb). 9. Heating chamber according to claim 8, so that hardened half-shells (40) are applied to the heating tubes (12) in the region of the holes (38) in the support consoles (Ia to IVb). 10. Heating chamber according to one of claims 1 to 9, characterized in that each support point (X, Y) is divided into p> 2 spaced supports with one console arrangement (I, II, III), each console arrangement (eg I) comprises a plurality of support brackets (eg Ia to Id) lying in the same plane. 11. Heating chamber according to claim 10, characterized in that at least two support brackets (z. B. Ia, Ib) in one and the same Console arrangement (z. B. I) have a different outer circumference. 12. Heating chamber according to claim 10 or 11, so that there is a free area between adjacent support brackets (e.g. Ia, Ib) in one and the same bracket arrangement (e.g. I). 13. Heating chamber according to one of claims 10 to 12, so that all the console arrangements (I, II, III) on one of the supports (X, Y) have the same, but rotationally offset configuration (FIGS. 2 to 5). 14. Heating chamber according to one of claims 10 to 13, so that p = 3 supports and p = 3 bracket arrangements (I, II, III) are provided per support point (X, Y). 15. Heating chamber according to one of claims 1 to 14, characterized in that in adjacent first and second console arrangements (z. B. I, II) first groups or non-adjacent second groups of the heating tubes (12) are supported by support brackets (Ia to Ila, Ib to Ilb, Ic to IIc, Id to Ild) (Fig. 6).