DE19627758A1 - Combustion plant for toxic pyrolysis gases, materials and residues - Google Patents

Abstract

The plant consists of a combustion chamber (1), a re-heater (8) and an annular waste heat boiler (14) surrounding both combustion chambers. The annular waste heat boiler is divided into segmented convection pipes (11) with vertical condenser heating surfaces (5). The annular waste heat boiler encloses the combustion and re-heating chambers only in one part. Connections for secondary and tertiary air inlets (33,34) are positioned in the part not enclosed by the annular waste heat boiler.

Description

The invention relates to a high temperature system for Burning toxic pyrolysis gases, pyrolysis residue substances and other waste materials with a Combustion chamber, an afterburner and one around both Combustion chambers arranged in a ring, being according to the main claim of the patent application 195 40 347.9 the afterburner in the lower area is expanded and a segment-shaped radiation space forms, above the segmental radiation space in the annular waste heat boiler between the outer and inner boiler tube wall with a radiation train vertically arranged superheater strands is provided and wherein the annular waste heat boiler in segmental convection cables with vertical arranged evaporator heating surfaces is divided.

In combustion chambers of the so-called pyro-melting process or the smoldering process is one Afterburner required, the carbonaceous Substances from the solid residues of charring (Pyrolysis) finally burns.

Because the combustion temperature for the solid residues and flue gases in the combustion chamber above the slag melting point of these residues must be Combustion temperatures of over 1200 ° C, in the Peak up to 1400 ° C, required.

From the previously unpublished DE 195 30 732.1 a system for smoldering and subsequent Burning waste and toxic residues known with a smoldering drum with discharge direction, a combustion chamber, an afterburning chamber, a waste heat boiler and an air preheater is. The combustion chamber is in the afterburner  let in. Both chambers have a common one Slag outflow.

The first boiler tube wall of the downstream waste heat kessel is parallel to the circular wall of the Nach combustion chamber arranged. The other boiler tube walls of the waste heat boiler are as rectangular boiler tube walls or bulkhead walls.

In the not yet published DE patent application 195 35 638.1 becomes a plant for charring and then burning waste and toxic residues described in the case of a Waste heat boiler a combination of combustion and Afterburner surrounds in a ring.

In the also not yet published DE patent application 195 40 347.9 is a system for Burning toxic pyrolysis gases, Pyrolysis residues and other residues with one Combustion chamber, an afterburner and one around both Combustion chambers in a ring-shaped waste heat boiler described the characteristics of the preamble of contains the present patent application.

The object of the invention is to take up the space System according to DE 195 40 347.9 to reduce and thus to minimize the manufacturing costs. In addition, should improved access to the combustion chamber can be achieved.

The solution to these tasks can be found in the characterizing features of claim 1. Advantageous refinements are the subject of Subclaims.  

In the incinerator according to the invention not only toxic pyrolysis gases and pyrolysis residues, but also carbon-containing substances in gaseous, solid or liquid form are burned, whereby such substances both individually or appropriately also in combination or with the addition of a fuel gas, for example natural gas. The Incineration is not specific to substances Composition limited.

Compared to the above State of the art systems with a circular waste heat boiler that houses the combustion chambers completely encloses, shows what is claimed here Concept the following advantages:

• - The cooling surfaces of the inner cylinder of the combustion chambers depending on the degree of containment the waste heat boiler, in the area not converted use on both sides,
• - The combustion chambers are not overheated boiler converted part easily accessible and secondary as well Tertiary air can be supplied easily,
• - Reduced when two parallel systems are arranged the space requirement and it is enough a. a common burner platform for both plants,
• - A more effective heating surface cleaning by tapping is made possible by the fact that the enclosed space in usually will be less than 260 °,
• - Corresponds to the smaller angle the proportion of the heating surfaces of the exterior and Inner cylinder, because of the conversion by the The waste heat boiler cannot be cleaned by knocking can, while the gap between  Inner and outer jacket and thus the proportion of radial heating surfaces that can be cleaned by tapping are enlarged accordingly.

The plant for burning carbonaceous Fabrics with the waste heat boiler according to the invention Heat is used for household waste and in particular for hazardous waste incineration at incineration temperatures doors of over 1200 ° C, at the top up to 1400 ° C, used.

The waste heat boiler with a segment-shaped circular cross-section, preferably at an angle of 200-260 ° the likewise circular combustion chamber afterburning chamber arranged. This constructive design is space-saving and has the advantage that the radiation losses to a minimum even at high temperatures can be limited. There is also one such execution no stretching problems.

To ensure that fumes are the afterburners leave chamber with particularly high temperature, in subsequent waste heat boiler cooled down as far be that at the outlet of the same a temperature of 300 ° C is not exceeded, the waste heat boiler with a segmental radiation train and with several segment-shaped convection boiler trains equips through which the hot flue gases meander be performed.

The radiation train with the superheater strands includes a segment section of 70-90 ° of the segment shaped waste heat boiler.  

The following convection trains with the evaporator heating surfaces designed as straight bulkheads are each form segments of 25-45 ° of segment-shaped waste heat boiler, the the Strah first convection train downstream due to the high temperature of the smoke to be cooled gases naturally the largest volume or segment claimed.

An embodiment of the invention is based on schematic drawings explained in more detail.

Show it:

Fig. 1 is a longitudinal section of the annular heat-recovery boiler,

Fig. 2 is a longitudinal section through a portion of the waste heat boiler,

Fig. 3 shows a cross section of the high-temperature combustion system above the radiation chamber.

Fig. 1 shows the structure of the high-temperature combustion system with the centrally arranged combustion chamber ( 1 ), with burner head ( 2 ) and cover ( 3 ), with an afterburner chamber ( 8 ) and the segmented waste heat boiler ( 14 ).

The combustion chamber ( 1 ) is formed by circular boiler tube walls ( 10 ) which are connected by upper collectors ( 4 ). In the area of the combustion chamber ( 1 ), the boiler tube walls ( 10 ) have no fireproof lining, since a constant heat dissipation takes place through targeted cooling of the boiler tube walls ( 10 ).

The afterburning chamber ( 8 ) is from the beginning of the dwell range of the flue gases to the transition into the waste heat boiler ( 14 ) at the end of the radiation chamber ( 13 ) with a refractory lining ( 7 ), which on the boiler tube walls ( 10 ) as well as on the outer boiler tube wall ( 9 ) is applied.

The flue gases are deflected upwards in the area of the lower collector ( 6 ) and arrive at the end of the radiation chamber ( 13 ) in the waste heat boiler ( 14 ).

Above the radiation space ( 13 ) superheater strands ( 28 ) are seen before for generating superheated steam. Saturated steam from the steam drum ( 15 ) is supplied via a saturated steam line ( 27 ), the superheated steam is discharged via the steam line ( 29 ).

After the segment-shaped radiation train ( 12 ) with the overheating strands ( 28 ), the flue gases pass into the segment-shaped convection trains ( 11 ) through which they are guided in a meandering manner. The cooled flue gases leave the waste heat boiler ( 14 ) via a flue gas line ( 25 ) with temperatures of approx. 300 ° C. Ash and unburned solid particles that occur during the cooling process are drawn off via ashes ( 16 ), the liquid slag flows from the combustion chamber ( 1 ) and afterburner chamber ( 8 ) via a slag drain ( 17 ) into a wet slag remover or other cooling device .

The burner head ( 1 , 3 ) let into the boiler tube walls ( 10 ) preheated combustion air ( 19 ) together with gaseous substances ( 20 ), solid residual substances ( 21 ) and liquid substances ( 22 ) for combustion in the combustion chamber ( 1 ) .

The lower header ( 6 ) is fed via a boiler feed water supply line ( 23 ) from the steam drum ( 15 ) boiler feed water and distributed to the outer (9) and inner boiler tube walls ( 10 ).

Saturated steam is fed from the upper collectors ( 4 ) to the steam drum ( 15 ) via a saturated steam line ( 24 ). The fresh air ( 18 ) is passed through an air preheater ( 32 ) for preheating the combustion air ( 19 ).

Fig. 2 shows a longitudinal section of a portion of the annular waste heat boiler ( 14 ) through one of the four convection cables ( 11 ) with ash discharge ( 16 ) arranged on the lower part below the collector ( 6 ).

The boiler tube walls ( 10 ) of the combustion chamber ( 1 ) and the afterburning chamber are charged with boiler feed water via the collector ( 4.6 ), the inner part of the afterburning chamber ( 8 ) is provided with a fireproof clothing ( 7 ).

The combustion chamber ( 1 ) is supplied with secondary air via an annular feed ( 33 ) and the afterburning chamber ( 8 ) is also fed with tertiary air for combustion via an annular feed ( 34 ). Unburned, liquid or pasty solids are withdrawn via a slag drain ( 17 ) below the afterburner chamber ( 8 ).

Fig. 3 shows a cross section of the high-temperature system through the afterburning chamber ( 8 ) and the segmented waste heat boiler ( 14 ) above the radiation chamber.

The annular waste heat boiler (14) is divided into a segment-shaped Strahlungszug (12) and in five segment-shaped Konvektionszüge (11), which are flowed through by the flue gas meandering shape (30, 31), wherein in Strahlungszug (12), the flue gases to the top (30) and are guided downwards ( 31 ) in the first convection cable ( 11 ).

The number and design of the convection trains ( 11 ) is designed so that the flue gases in the last convection train ( 11 ) are guided downwards ( 31 ). According to the design of the combustion chamber and the maximum amount of flue gas, the radiation train ( 12 ) comprises a segment of 70-90 °, in the exemplary embodiment 75 ° of the annular waste heat boiler ( 14 ), the convection trains ( 11 ) each comprise segments of 25-45 °, in the exemplary embodiment 27-38 °.

The Ascheausträge (16) are always arranged in the bottom of Konvektionszüge (11), wherein the ash effluents (16) and below the evaporator heating surfaces (5) may be arranged at the bottom of two Konvektionszügen (11).

On the last, 27 ° wide convection duct ( 11 ) is the flue gas manifold ( 25 ), through which the flue gases cooled to approx. 300 ° are discharged and fed to a flue gas cleaning system, not shown.

In the radiation train ( 12 ) vertically arranged superheater strands ( 28 ) are arranged, in which a part of the saturated steam coming from the evaporator heating surfaces ( 5 ) is overheated.

Reference list

1 combustion chamber
2 burner heads of 1
3 coverage of 1
4 Upper collector
5 evaporator heating surfaces
6 lower collector
7 Fireproof lining
8 afterburner
9 Outer boiler tube wall
10 Inner boiler tube wall
11 convection cable
12 radiation train
13 radiation room
14 waste heat boiler
15 steam drum
16 ash discharge
17 slag outflow
18 fresh air supply line
19 Combustion air supply line
20 gas line
21 Residual material feed
22 Liquid line
23 boiler feed water supply line
24 saturated steam pipe
25 flue gas outlet
26 Melt flow fuse burner
27 Steam line to the superheater line
28 superheater train
29 Outlet pipe for superheated steam
30 Flue gas flow upwards
31 Flue gas flow down
32 air preheaters
33 secondary air supply
34 Tertiary air supply.

Claims (2)

1. Plant for burning toxic pyrolysis gases, pyrolysis residues and other residues with a combustion chamber, an afterburning chamber and a waste heat boiler arranged in a ring around both combustion chambers,
According to the main claim of patent application 195 40 347.9, the afterburning chamber ( 8 ) is expanded in the lower region and forms a segment-shaped radiation space ( 13 ),
a radiation train ( 12 ) with vertically arranged superheater strands ( 28 ) is provided above the segmented radiation space ( 13 ) in the annular waste heat boiler ( 14 ) between the outer ( 9 ) and inner boiler tube wall ( 10 ), and
the annular waste heat boiler ( 14 ) being subdivided into segment-shaped convection cables ( 11 ) with vertically arranged evaporator heating surfaces ( 5 ),
characterized,
that the annular waste heat boiler ( 14 ) surrounds the combustion chamber ( 1 ) and the afterburning chamber ( 8 ) only in a partial area. 2. Plant according to claim 1, characterized in that in the area not converted from the annular waste heat boiler ( 14 ), connections for secondary and tertiary air feeds ( 33 , 34 ) are arranged.