DE19726150C1 - Rotary waste pyrolysis drum - Google Patents

Abstract

A rotary solids heating chamber, especially a waste pyrolysis drum, has internal heating tubes (12) which are fixed to end plates and which are supported at intermediate points by passage through holes (38) in brackets (32) fixed to the inner wall, the tubes (12) being fitted with reinforcing elements (40) in the region of the holes (38). The novelty is that the tubes (12) are mounted with play and without bushes in the holes (38) of the support brackets (32).

Description

The invention relates to a around its longitudinal direction rotatable heating chamber for solid material, especially smoldering drum for waste, with a number lying inside Heating pipes, each with one end on a first End plate and the other end to a second end plate are attached, being between the end plates for supporting the Heating pipes is provided at least one support point has a support bracket attached to the inner wall, wherein the heating pipes are placed in holes in the support bracket, and being reinforced on the heating pipes in the area of the holes Kung elements are applied.

The heating chamber is used in particular as a smoldering drum for waste used for the purpose of thermal waste disposal, be preferably after the smoldering-burning 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 gung are described for example in EP 0 302 310 A1. The plant for thermal waste disposal after the threshold Burning process contains one as essential components Smoldering chamber as heating chamber (also as smoldering drum or as Pyrolysis reactor) and a high temperature Brennkam mer. The smoldering chamber uses a waste transport system facility abandoned waste in smoldering gases and pyrolysis residue around. The carbonization gases and the pyrolysis residues are then after appropriate processing the burner of the Hochtem temperature combustion chamber supplied. In the high temperature burning chamber creates molten slag that over a Ab train is removed and after cooling in glassy form  is present. The resulting flue gas is a flue gas line fed a chimney as an outlet. In this flue gas pipe are in particular a heat generator as a cooler direction, a dust filter system and a flue gas cleaning system plant installed.

As a smoldering chamber (pyrolysis reactor) is usually one relatively long smoldering drum rotating around its longitudinal axis used, the inside a variety of parallel heating pipes has, where the waste largely in the absence of air is heated. The heating pipes are on the forehead ten of the smoldering drum from the outside into the inside of the smoldering drum mel led. To prevent gas exchange between the environment and the interior of the smoldering drum takes place, the heating pipes must pass through the forehead sides are sealed. Due to thermal expansion the tubes are movable at least at one end by a Be passed through. In DE 33 46 338 A1 so As in DE 43 26 678 A1, suggestions are made for this.

For the purpose of high profitability and sufficient Achieving pyrolysis at a high throughput can Smolder drum up to 30 m long. Are accordingly also the heating pipes up to 30 m long.

A smoldering drum is known from WO 95/06697 A. At the There are several to support the heating pipes in the interior Support points are provided to prevent the heating pipes from sagging prevent. The support points include support brackets that are attached to the inner wall of the smoldering drum are attached and in extend the interior of the smoldering drum. The support brackets have multiple holes or holes through each a heating pipe is guided. To protect the heating pipe is a Socket provided in the corresponding hole of the support console is housed. Through this jack that Heated pipe, the half-shells in the area of the hole points.  

In this known arrangement there is a risk because the heating pipe, for example, when heating the smoldering drum stretches in length and in diameter. The distance between the half shells and the socket attached to the hole can namely so far be reduced so that the heating tube is not in the socket can move more freely. An increasing length extension of the  The heating tube can get stuck (jamming) of the Heating pipe ultimately to tear off the support bracket from the Guide the inside wall of the smoldering chamber.

The object of the invention is a heating chamber, in particular a smoldering drum with heating pipes in the interior admit a sliding bearing of the heating pipes in Support brackets even with different expansions of the Heating pipes and the support brackets is ensured so that the The risk of jamming is reduced. At the same time The construction of the smoldering drum is as compact as possible will.

The object is achieved according to the invention in that the arrangement known from WO 95/06697 for supporting the Heating pipes in the area of the support brackets changed accordingly is that the heating pipes are free and without bushings in the holes the support bracket.

The initially surprising idea of omitting the sockets which, according to WO 95/06697 A1, is ultimately specifically for this purpose are thought to increase operational safety and operating time hen, the following is an essential consideration of the invention reasons: With a different thermal expansion between Heating tube and bushing reduces the distance between the Heating tube and the socket. This happens, for example, at Warm up the smoldering drum when the heating pipes are hot Heating gas can be charged and at the same time the socket or the Support bracket is still cold.

The distance between the heating pipe and socket is usually to be kept as low as possible because during the rotation of the Smoldering chamber that is loosely guided through the fixed socket Grinds the heating pipe along the socket. Grinding along or you can slide along the heating pipe in the hole - seen in cross-section - as two interlocking circles to introduce. The smaller, inner circle (heating pipe)  lies on the inside of the outer circle (socket) and glides along the inside without worrying about his turn its own axis, d. H. without rolling, so that the in inner circle along the line of contact to the outer circle grinds. The greater the distance between the socket and the heating pipe is, d. H. the greater the difference between the outer Diameter of the heating tube and the inner diameter of the Socket, the longer is the circumference at which that Heating tube ent in the socket at a higher speed long loops. This has a high wear on the heating pipe result in premature breakage of the heating tube can lead in the area of the socket. To avoid excessive ver To prevent wear of the heating pipe, it is therefore necessary the distance between the heating pipe and socket is possible from the start as low as possible.

This distance, which is already small when cold, is the result of the different thermal expansions smaller, so that Sliding of the heating pipe in the socket is no longer guaranteed is, d. H. the friction between the heating pipe and the socket is minimal at least too high at one point for free sliding, so that the heating tube is clamped in the socket at least for a short time is. It should be noted that the heating pipe is not just a ra diale thermal expansion, but also an axial thermal expansion voltage, d. H. thermal expansion along the length axis of the smoldering drum. The linear expansion at festge clamped heating tube now leads to the complete support con sole in the direction of the longitudinal axis at an angle to the Is tilted perpendicular to the longitudinal axis. The firm with the Support bracket connected socket is also against the sink right inclined. But this means nothing else than that the axis of the socket no longer matches the axis of the heating pipes matches, or in other words: the heating pipe runs diagonally through the socket. However, the socket now has one Linear expansion, which inevitably leads to the fact that heating pipe running diagonally through the socket itself on the book seizes input or socket output, d. H. yourself full  constantly and undetachably stuck in the socket. With increasing the length of the heating tube therefore increase forces acting on the support bracket, causing the support con sole is tilted more and more until it is finally removed from the Inner wall of the smoldering chamber is torn off.

Only after this consideration does one come to the surprising and not obvious realization that the jack for a sliding storage of the heating tube is rather a hindrance. The after it is very important to do without the socket, to slide the heating tube in the associated hole of the To ensure support bracket.

To prevent wear when the heating pipes slide along the Avoid holes are in the area of the holes Reinforcement elements attached to the heating pipes. Prefers are at least some of these reinforcement elements as half shells and / or slotted sleeves formed. The reinforcement Kungselemente offer the advantage that only they wear out and the heating pipes remain intact. If necessary the reinforcement elements can also be easily replaced. The half shells or the slotted sleeve are two alterna tive possibilities, such a reinforcing element in the loading to make a hole in the corresponding heating pipe gene.

In a preferred embodiment, the reinforcements elements each have a coat on one end is flattened in a wedge shape. The flattened or wedge-shaped bevelled end face of the reinforcing elements allows the reinforcement element between the hole without great effort and the heating pipe that is already done through the hole is to insert.

It is also useful if the reinforcing elements to increase their wear resistance from one material, in particular steel, which is hardened or tempered.  

If short revision intervals are provided, can also ordinary steel can be used for reinforcing elements which then have to be replaced more often.

The reinforcing elements preferably have a wall thickness of about 8 mm on, which ensures a sufficiently long operation time is possible without the heating pipes wearing out exhibit.

In a further, very advantageous embodiment the reinforcement elements applied to the heating pipes NEN outer diameter of about 3 to 6 mm, in particular whose 4 to 5 mm, is smaller than the inner diameter of the assigned hole.

These dimensions are based on this side's findings optimum wear resistance, operational safety and Size of the smoldering drum with sufficient heat transfer in reached the waste. The difference between the outer Diameter of the reinforcing elements and the inner diameter The diameter of the holes is large enough to clamp to effectively avoid the heating pipes in the holes. The differences On the other hand, renz is also sufficiently small chosen to be the length of the circumferential line that the heating pipe is on due to the rotating movement of the smoldering drum within the fixed attached hole to keep as small as possible. This leads to little wear on the reinforcement elements.

Due to the small difference between the outer diameter water of the reinforcing element and the inner diameter of the Hole as well as due to the absence of the socket is above it as a further major advantage a largely allows space-saving arrangement of the heating pipes. Prefers is an almost ge along the inner wall of the smoldering drum closed heating pipe circuit arranged. In addition, the Heating pipes along rows of heating pipes in the interior of the  Pass in the smoldering drum. Given a heating surface for adequate heat transfer into the waste is essential number of heating pipes. A minimization of the distance between the heating pipes thus causes immediate bar that the smoldering drum as a whole is made smaller can, which leads to material and cost savings. A Minimizing the mutual distance between the heating tubes ren and also between the heating pipes and the inner wall of the Heating chamber is also particularly advantageous because falling-through of waste parts, in particular fine granular waste that prevents heating pipes. The Ab case is therefore held between the heating pipes, so that a high heat transfer from the heating pipes to the waste light is.

In a further particularly preferred embodiment the support brackets a thickness of 20 to 40 mm, in particular of about 30 mm.

With these dimensions there is an optimum between wear and operational safety achieved. Because of the relatively large Thickness of 30 mm is the contact surface of the Heating tube in the socket is relatively large, so that the amplifier tion elements over a relatively large range will. The wear in the radial direction as a result the strength of the reinforcing element decreases, is therefore ge ring. On the other hand is the strength of the support bracket sufficiently small to prevent the heating pipe from tilting in the Prevent support bracket and thus a safe permanent drive to ensure.

In a preferred embodiment, the heating chamber is approximately 30 m long, and the heating pipes have an outer diameter of about 100 mm, the reinforcing elements an outer Diameter of about 116 mm and the holes an inner Diameter of about 120 mm.  

It is also useful to place the heating tubes in a support stood from about 7 m to support.

It is also advantageous to use the reinforcing elements each because by means of at least one weld seam on the subject to fix the heating pipe.

Exemplary embodiments of the invention are described below of the three figures of the drawing explained. Show it:

Figure 1 shows a smoldering-firing plant in a basic sectional view.

Figure 2 is a schematic section through the smoldering chamber with a number of heating pipes in the Schwelkam mer.

Fig. 3 is a schematic section of a support bracket with a heating tube carried out according to the invention.

According to Fig. 1 A solid waste via a feed or on will display device 2 and a worm 4, which is driven by a motor 6 and is disposed in a feed tube 7, is introduced centrally into a pyrolysis reactor or a low-temperature carbonization. 8 The smoldering chamber is an internally heatable, about its longitudinal axis 10 rotatable pyrolysis or smoldering drum 8 , which can have a total length l of 15 to 30 m, which works at 300 to 600 ° C, which is largely operated under the exclusion of oxygen and which besides volatile carbonization gas s generates a largely solid pyrolysis residue f. It is an inner-tube carbonization drum 8 with a plurality (e.g. 50 to 200) of heating tubes 12 aligned parallel to one another, of which only four are shown in FIG. 1, which are arranged in the interior 13 . At the right or "hot" end, an inlet chamber 14 for heating gas h is provided, and at the left or "cold" end an outlet chamber 16 for the heating gas h is arranged.

The pyrolysis drum 8 is on the discharge side a Austragvor direction 18 , the nozzle with a carbonization trigger 20 for the discharge of carbonization gas s and with a py rolysereststoffgangs 22 is provided for the delivery of solid pyrolysis residue f.

The heating tubes 12 are each fixed at one end to a first end plate 28 and at the other end to a two end plate 30 . The axis of the heating tubes 12 is oriented perpendicular to the surface of the end plates 28 , 30 , which rotate along the longitudinal axis 10 of the carbonization drum 8 .

From Fig. 1 it is clear that between the end plates 28 , 30 two support points X, Y for supporting the (otherwise possibly sagging) heating tubes 12 are provided. Seen in the transport direction of waste A, the first support point X is one third (1/3 l) and the second support point Y is two thirds (2/3 l) of the total length l of the smoldering drum 8 , so that the distance between the two supports represent X, Y with a total length l of the drum of 20 m is about 7 m. Each support point X, Y is subdivided into supports I, II and III that were spaced apart from one another. The supports I, II and III each have support consoles 32 , which are attached to the inner wall 33 of the smoldering drum 8 , as shown in FIG. 2. On the supports I, II and III is advantageous because a third of the total number of heating tubes 12 is supported in order to hinder the flow of waste A through the Schweltrom mel 8 as little as possible.

According to FIG. 2, a number of heating tubes 12 is arranged on the inner wall 33 along in a closed circle. In the direction of the longitudinal axis 10 to extend additional Lich rows of heating tubes 12 which are curved in the direction of rotation 35 of the smoldering chamber 8 . According to FIG. 2, are shown in in way of example four support brackets 32, a number of heating tubes 12 combined in a group, each of which is passed through a support bracket 32. The group of heating tubes 12 includes both a number of the arranged along the inner wall of the heating tubes 12 and ren extending in the direction of the longitudinal axis 10 series of Heizroh 12th The individual heating tubes 12 are each guided through a hole 38 provided for them (see FIG. 3) in the support bracket 32 .

According to Fig. 3 32, the supporting bracket 38, a hole or a recess, for example a bore, through which the heat pipe is passed 12th On the heating tube 12 , a reinforcing element 40 is fixed to weld seams 41 . The length of the reinforcing element 40 is preferably 70 mm. Advantageously, it consists of hardened steel, so that a high wear resistance is achieved even with a relatively low strength of the reinforcement element 40 . The heating tube 12 is free together with the reinforcing element 40 , ie without a further socket which is fastened to the support bracket 32 , passed through the hole 38 of the support bracket 32 .

There is a gap 42 between the reinforcing element 40 and the support bracket 32 . This gap 42 has a width of approximately 2 mm when the heating tube 12 is centrally stored in the hole 38 . The outer diameter d1 of the heating tube 12 is preferably 100 mm, the strength of the Verstärkungsele mentes 40 is preferably 8 mm, so that the heating pipe 12 mounted on the reinforcing member 40 has an outer diameter d2 of 116 mm. In addition to the total gap width of 4 mm, the hole has an inner diameter d3 of approximately 120 mm.

This spacing between the hole 38 and the reinforcement element 40 is sufficient to prevent the heating tube 12 from jamming or jamming in the hole 38 and to ensure a sliding mounting of the heating tube 12 in the support bracket 32 . Even with different thermal expansions of the heating tube 12 and the support bracket 32 plus possibly unfavorable manufacturing fluctuations, for example with the outer diameter d2 of the heating tubes 12 , these dimensions ensure adequate protection against jamming of the heating tube 12 in the support bracket 32 . For use as heating tubes 12 , commercially available and relatively inexpensive tubes with the usual manufacturing tolerances can be used.

The support bracket 32 preferably has a thickness or width b of approximately 30 mm in order to achieve the best possible rigidity. The width b of 30 mm is sufficiently small to prevent the heating tube 12 from tilting in the support bracket 32 , as is favored, for example, by a bushing. At the same time, the width b is chosen to be sufficiently large at 30 mm in order to keep the "Hertzian surface pressure" as small as possible, that is to say the ratio between the force with which the heating tube 12 is pressed against the support bracket 32 and the area on which the heating tube is located 12 comes to rest on the support bracket 32 . Thus, with these dimensions, an op timum between the least possible wear of the reinforcing elements 40 and ensuring the sliding mounting of the heating tube 12 in the support bracket 32 to increase the operational safety is achieved.

Claims (13)

1. About its longitudinal axis ( 10 ) rotatable heating chamber for solid material, in particular smoldering drum ( 8 ) for waste (A), with a number in the interior ( 13 ) lying heating pipes ( 12 ), each with one end on a first end plate ( 28 ) and are attached at the other end to a second end plate ( 30 ), at least one support point (X, Y) being provided between the end plates ( 28 , 30 ) for supporting the heating pipes ( 12 ), said support point (X, Y) on the inner wall ( 33 ) attached support bracket ( 32 ), the heating tubes ( 12 ) being accommodated in holes ( 38 ) in the support bracket ( 32 ), and wherein reinforcing elements ( 40 ) are applied to the heating tubes ( 12 ) in the region of the holes ( 38 ) are characterized in that the heating pipes ( 12 ) are freely and without bushings in the holes ( 38 ) of the support bracket ( 32 ). 2. Heating chamber according to claim 1, characterized in that at least some of the reinforcing elements ( 40 ) are formed out as half-shells. 3. Heating chamber according to claim 1 or 2, characterized in that at least some of the reinforcing elements ( 40 ) are designed as slotted sleeves. 4. Heating chamber according to one of the preceding claims, characterized in that the reinforcing elements Ver ( 40 ) each have a jacket which is flattened in a wedge shape on one end face. 5. Heating chamber according to one of the preceding claims, characterized in that the reinforcing elements Ver ( 40 ) consist of a material, in particular steel, which is hardened or tempered. 6. Heating chamber according to one of the preceding claims, characterized in that the reinforcing elements ( 40 ) have a wall thickness of approximately 8 mm. 7. Heating chamber according to one of the preceding claims, characterized in that the reinforcing elements ( 40 ) applied to the heating tubes ( 12 ) have an outer diameter (d2) which is approximately 3 to 6 mm smaller than the inner diameter (d3) of the associated one Loches ( 38 ). 8. Heating chamber according to one of the preceding claims, characterized in that the reinforcing elements ( 40 ) applied to the heating tubes ( 12 ) have an outer diameter (d2) which is approximately 4 to 5 mm smaller than the inner diameter (d3) of the associated one Loches ( 38 ). 9. Heating chamber according to one of the preceding claims, characterized in that the support brackets ( 32 ) have a thickness (b) of 20 to 40 mm. 10. Heating chamber according to one of the preceding claims, characterized in that the support brackets ( 32 ) have a thickness (b) of about 30 mm. 11. Heating chamber according to one of the preceding claims, characterized in that it is approximately 30 m long, that the heating tubes ( 12 ) have an outer diameter (d1) of approximately 100 mm, the reinforcing elements ( 40 ) have an outer diameter (d2) about 116 mm and the holes ( 38 ) have an inner diameter (d3) of about 120 mm. 12. Heating chamber according to one of the preceding claims, characterized in that the support distance between two neighboring support points (X, Y) approximately Is 7 m.   13. Heating chamber according to one of the preceding claims, characterized in that the reinforcing elements Ver ( 40 ) are each fastened by means of at least one weld seam ( 41 ) on the heating tube ( 12 ) in question.