EP0716676B1 - Rotary heating chamber for solids - Google Patents

Abstract

A heating chamber for solid material, preferably a low-temperature carbonization drum for waste, is rotatable about its longitudinal axis and is equipped with a number of heating tubes that are disposed in an interior space and are aligned approximately parallel to one another. In order to ensure that only fine material can collect between the heating tubes and the inner wall surface of the heating chamber, the heating tubes, as viewed in cross-section, are disposed in a virtually closed row along the wall. Dummy tubes which are preferably easy to remove and preferably have the same diameter as the heating tubes, are located in this row, which may be circular.

Description

The invention relates to a rotatable around its longitudinal axis Heating chamber for solid goods, especially on a smoldering drum for waste, with a number housed inside, approximately parallel aligned heating pipes.

The heating chamber is used in particular as a smoldering drum for waste used for the purpose of thermal waste disposal, preferred after the smoldering process.

In the field of waste disposal is the so-called Smoldering process became known. The procedure and a plant for thermal waste disposal operating afterwards are described, for example, in EP-A-0 302 310. The plant for thermal waste disposal using the smoldering-burning process contains a as essential components Smoldering chamber (pyrolysis reactor) and a high-temperature combustion chamber. The smoldering chamber uses a waste transport device abandoned waste in carbonization gases and pyrolysis residues around. The carbonization gases and the pyrolysis residues are then, after suitable work-up, the burner of the high-temperature combustion chamber fed. In the high temperature combustion chamber creates molten slag that over a Deduction is removed and after cooling in glassy Form is present. The resulting flue gas is fed through a flue gas line fed to a chimney as an outlet. In this flue gas pipe are in particular a heat recovery steam generator as Cooling device, a dust filter system and a flue gas cleaning system built-in.

As a smoldering chamber (pyrolysis reactor) is usually one rotating, relatively long smoldering drum used has a large number of parallel heating pipes on the inside where the waste is largely heated in the absence of air becomes. The smoldering drum rotates about its longitudinal axis. The longitudinal axis is preferably somewhat opposite the horizontal inclined so that the solid char at the exit of the Collect the smoldering drum and from there via a discharge pipe can be carried out. When turning the waste through the heating pipes are lifted up and fall down again. Hereby and by moving waste becomes the transport of the solid (Dust, chunks of carbon (coke), stones, bottles, Metal, ceramic parts, etc.) towards the Discharge opening of the smoldering drum accomplished.

Important with such a heating chamber, especially when charring of waste, it is that through the individual heating pipes as much heating area as possible is made available. Around To accomplish this have been ranks in the prior art provided by individual heating pipes, which - in cross section seen the smoldering drum - especially straight from the inner wall of the smoldering drum towards the interior extended. In addition, were in the prior art occasionally on and along the inner wall heating pipes ("peripheral heating pipes") arranged, but only as needed. In no case has it been practically closed Pipe circle, that is, a pipe circle without gaps. The peripheral arrangement of the - possibly irregular spaced - for example, heating pipes could leave a gap exhibit at the point where there is an opportunity to inspect the smoldering drum existed, for example by arranging one Manhole. It should also be noted that the distance between two neighboring heating pipes on the inner wall so far was practically arbitrary. That means this distance was constructive conditional and a function of the required heating surface.

The consequence of this irregular arrangement of the heating pipes the inner wall was a load on the smoldering drum jacket due to falling waste parts. Beyond that could Metal parts or other solid pieces between the drum wall and clamp the directly adjacent heating pipes. This reduced the available heating area.

The object of the present invention is a heating chamber of the type mentioned in such a way that in the area a sufficiently large inside wall of the heating chamber Heating surface in the form of heating pipes for heating or pyrolysis of the discarded waste is available. With others Words: The risk of metal parts jamming and other solid chunks should be greatly reduced, so that the side facing the inner wall of the heating chamber individual heating tubes optimally used for heat transfer can be.

This object is achieved in that the Heating pipes - seen in cross section - in a practically closed one Row arranged along the wall of the interior are, and that the distance of the heating pipes (12b) from the wall of the Interior (13) and the mutual distance between the heating tubes (12b) smaller than is half the diameter of a heating tube (12b).

The invention is therefore based on the consideration that the Ensure availability of a high heating surface lets that the individual heating pipes on the inner wall if possible be arranged closely. In other words, to prevent that the chunks mentioned get stuck in the space the heating pipes on the inside of the drum a practically closed jacket, with a cylindrical one So smolder drum form a tube circle. The distances between the individual heating pipes should be as narrow as possible to get voted.

It should be emphasized again: by arranging one practically closed, for example circular, bundle it is achieved that no coarse material through the gaps between the individual heating pipes on the inner wall of the Heating chamber can fall and erode or burden it. It is thus ensured that only the fine waste material between these gaps on the inner wall the heating chamber falls. This also ensures that no metal waste or other solid chunks jam between the individual heating pipes and the inner wall can. So only the fine goods and that is in the interior gas in thermal contact with the the inner jacket side of the individual heating tubes.

In summary, the main advantages are there too see that only fine waste material on the inner wall the heating chamber can fall, and that this inner wall mechanically is practically not burdened. It also follows a good one for a pyrolysis reactor or a smoldering drum Heat exchange from the heating pipes into the gas atmosphere and in the fines layer. The heat radially from the heating pipes is emitted to the outside, is therefore used very well.

According to a development, the on the inner wall of the Heating chamber located heating pipes are protected against falling coarse material from so-called impact shells from one resistant material. This is in particular around semi-cylindrical shells. Such protection can also be provided for heating pipes that are - on straight or curved lines (seen in cross section) - inside extend into the heating chamber.

To get started in the heating chamber, one is usually one Provide manhole. According to another, preference is now given Training provided that - if necessary in the area of a such manhole blind pipes (dummies) in the series of Heating pipes are used. These dummy pipes are pipes that are not flowed through by a heating gas. You are preferred arranged easily removable. This means that when the heating chamber is in operation, the row of heating pipes on the inner wall is closed while being inspected by the Personnel in the area of the manhole by dismantling the dummy pipes is interrupted.

In practice it has been shown that a distance between two neighboring peripheral Heating pipes and / or blind pipes in the range from 20 to 40 mm are possible and is well suited.

The blind pipes mentioned above should be the same Have diameters like the peripheral ones arranged on the inner wall Heating pipes.

The distance of the (preferably closed) pipe circle from the The inner wall of the heating chamber should be as small as possible. He will usually be determined by design specifications, for example by attaching the heating and / or Blind pipes on end plates. Usually this distance can are between 20 and 40 mm.

Figur 1 eine Schwelanlage mit einer Schwelkammer für Abfall, die im Rahmen des Schwel-Brenn-Verfahrens eingesetzt werden kann, in einer prinzipiellen Schnittdarstellung;

Figur 2 einen Blick auf den Querschnitt einer ersten Konfiguration von Heizrohren in der Schweltrommel von Figur 1 und

Figur 3 einen Blick auf den Querschnitt einer zweiten Konfiguration von Heizrohren in der Schweltrommel von Figur 1.

Exemplary embodiments of the invention are explained in more detail below with reference to three figures. Show it:

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

Figure 2 is a view of the cross section of a first configuration of heating tubes in the carbonization drum of Figure 1 and

3 shows a view of the cross section of a second configuration of heating pipes in the carbonization drum of FIG. 1.

According to Figure 1, solid waste A via a feed or feed device 2 with chute 3 and via a screw 4, which is driven by a motor 6 and in a feed tube 7 is arranged centrally in a pyrolysis reactor or a smoldering chamber 8 is introduced. The smoldering chamber 8 is in the Embodiment an internally heated, about its longitudinal axis 10 rotating smoldering or pyrolysis drum, which is a length of 15 to 30 m, which works at 300 to 600 ° C, which is operated largely with the exclusion of oxygen and which, in addition to volatile carbonization gas, is a largely solid pyrolysis residue generated. It is an internally drilled one Smoldering drum 8 with a variety (for example 50 to 200) of heating pipes aligned parallel to each other 12, of which only four are shown in Figure 1, the interior 13 are arranged. On the right or "hot" end is an inlet for heating gas h in the form of a dormant, sealed Heating gas inlet chamber 14 is provided, and on the left or "Cold" end is an outlet for the heating gas h in the form of a resting, sealed heating gas outlet chamber 16 is arranged. The longitudinal axis 10 of the smoldering drum 8 is preferably opposite inclined horizontally so that the outlet is on the right The "hot" end is lower than the inlet shown on the left for waste A. The smoldering drum 8 is preferably on slight negative pressure kept from the environment.

The pyrolysis drum 8 is on the output or discharge side a rotating central discharge pipe 17 a discharge device 18 downstream, with a carbonization gas discharge nozzle 20 for the discharge of the carbonization gas s and with a Pyrolysis residue outlet 22 for the discharge of the solid pyrolysis residue f is provided. One at the smoldering gas discharge nozzle 20 connected carbonization line is connected to the Burner of a high temperature combustion chamber (not shown) connected.

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

From Figure 1 it is clear that the heating tubes 12 each with one end at a first end plate 28 and with her other end are attached to a second end plate 30. The attachment to the end plates 28, 30 is made so that preferred easy replacement of the heating pipes 12 results. The end of the heating tubes 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 The axis of the heating tubes 12 is perpendicular to the surface of the end plates 28, 30 aligned. In the shown Construction is noted that the individual heating tubes 12th are thermally and mechanically highly stressed, and that the end plates 28, 30, which are also called tube plates or drum tube plates could be referred to the longitudinal axis 10 of the Turn smoldering drum 8 too.

Between the end plates 28, 30 are two support points X, Y to support the (otherwise sagging) Heating tubes 12 provided. In the direction of transport of waste A seen the first support point X is about a third (1/3 1) and the second base Y about two thirds (2/3 1) of the total length 1 of the smoldering drum 8. Here are Support or support brackets 31, 32 in the form of rounded perforated plates made of metal, for example steel. she are attached to the inner wall 33.

The heating tubes 12 can be arranged in one configuration be as shown in Figure 2 and Figure 3. Then there are a variety of peripherally arranged heating pipes 12b and a plurality along curved or straight lines arranged heating tubes 12a for heating the more centrally lying waste. The curvature depends on the rotation the smoldering drum 8, which is indicated by an arrow 35.

From Figure 2 it is clear that six shorter and six longer non-radial rows of internal heating tubes 12a are provided. The peripheral heating tubes 12b are located on a practically complete or closed circle the inner wall 33 of the smoldering drum 8.

The non-radial rows start according to FIGS. 2 and 3, respectively in the area of the inner wall 33. They are - and that is from of particular importance - curved against the direction of rotation 35 (see Figure 2) or inclined (see Figure 3). Thereby it is guaranteed that when rotating about the longitudinal axis 10 waste A accumulating on the heating pipes 12a, 12b Fall down early and therefore no significant drop can reach. This eliminates the risk of damage from Chunks contained in waste A are effectively reduced.

For clarification, an obtuse angle α is shown in FIG the alignment of the individual rows to the tangent entered the wall of the smoldering drum 8.

For good smoldering of waste A it is also provided that the mutual distance between the individual heating tubes 12a less than half the diameter of a heating tube 12a of that Row is. This also applies to the peripheral heating pipes 12b.

In Figure 3 are on a single linear row protection or Baffles 40 shown. The remaining linear rows as well as the curved rows of heating tubes 12a in Figure 2 - facing the central axis 10 also with such Baffles 40 made of resistant material. The same applies to baffles 50, the peripheral ones Heating tubes 12b can be provided in Figures 2 and 3. Of these baffles 50 are for clarity only two shown in FIG.

In Figure 3 it is also shown that in the area of a schematic illustrated manhole 60, through the maintenance or repair work Personnel can enter the interior 13, the circular row of the heating pipes 12b through blind pipes 12D same length and same outer diameter completely is added. These dummy tubes 12D are on the end plates 28, 30 attached easily detachable. In the event of maintenance or repairs they will be removed. All tubes 12b, 12D provide for operation ensuring that only fine material can reach the inner wall 33. Seen overall, the tubes 12a, 12D are practical on one completely closed circular ring arranged closely adjacent.

Claims (5)

1. Heating chamber for solid material, which chamber is rotatable about its longitudinal axis (10), preferably a low-temperature carbonization drum (8) for waste (W), having a number of heating tubes (12b) accommodated in the interior space (13) and aligned approximately parallel to one another, characterized in that the heating tubes (12b), viewed in cross-section, are arranged along the wall (33) of the interior space (13) and that the spacing of the heating tubes (12b) from the wall of the interior space (13) and the mutual spacing of the heating tubes (12b) is less than half the diameter of a heating tube (12b).
2. Heating chamber according to Claim 1, characterized in that the spacing of the heating tubes (12b) from the wall of the interior space (13) is between 20 mm and 40 mm.
3. Heating chamber according to Claim 1 or 2, characterized in that the mutual spacing of the heating tubes (12b) is between 20 mm and 40 mm.
4. Heating chamber according to any one of Claims 1 to 3, characterized in that dummies (12D) which are easy to remove are arranged in place of some heating tubes (12b).
5. Heating chamber according to Claim 4, characterized in that the dummies (12D) have the same diameter as the heating tubes (12b).

Images