DE19611792A1 - Process and plant for cleaning pollutant-laden gases, especially flue gases - Google Patents

Abstract

In a process for cleaning (especially) flue gases containing e.g. dioxins, furans, heavy metals, sulphur dioxide, HCl, HF etc., a fluidised bed of inert particulate material is generated, through which the gas steam passes. A solid reaction/adsorption medium is fed into or onto the bed from above and into the gas stream in heavily super-stoichiometric quantities. Unspent medium is subsequently separated from and then returned to the gas stream, whilst spent medium is removed altogether. Also claimed is a plant for the process which includes at least one fluidised bed reactor through which the pollutant-laden gas flows, together with at least one arrangement for separation and recirculation of the unspent medium to the reactor entry and at least one device for removal of the spent medium. In addition to inlets and outlets for the gas, at least one additional inlet to the reactor is provided for the reaction/adsorption material above level of the perforated plate or bubble cap tray at the base of the bed.

Description

The invention relates to a method and an arrangement for Disposal of an exhaust air-ash mixture from a dry ash container.

The e-filter ash is conveyed into a dryer by means of conveying air ash container passed, the conveying air by means of Hose cyclone or cloth filter separator from the ashes is separated. Hose cyclone separators have the disadvantage on that still in the exhaust air from the dry ash container there is a high ash content. Furthermore, there is Danger of filter breakthroughs that increase Ejection of dust result.

It is known that the exhaust air-ash mixture of the dry ash blown into the flue gas stream of the steam boiler will (DE 42 12 524). This increases the dust to be conveyed quantity and thus the wear on the pipes and Channels. Furthermore, there is a recycle mode of exhaust air known (DE 28 13 428), which also increases Wear leads.

The invention has for its object that exhaust air ash Separate mixture from a dry ash container and turn on then discard the separated media.

This is achieved in that the exhaust air Ash mixture and circulating water in a wet separator brought the resulting dust-free exhaust air into the Flue gas flow and the water-ash mixture in the scraper belt the ash removal system of the steam boiler.

According to the invention, the exhaust air-ash line is to be used the dry ash container is integrated in a wet separator, which is a pressurized water pipe, a dust-free exhaust air pipe and has a water-ash line, the dust-free Exhaust duct connected to the flue gas duct as well as the what ashes pipe to the scraper belt of the ash removal system of the Steam boiler is guided.

The invention is explained in more detail using an exemplary embodiment tert.

The steam boiler 1 has the ash funnel 2 and the scratch belt 3 , to which the wet ash belt 4 connects. After the steam boiler 1 , the flue gas duct 5 with the E-Fil ter 6 is arranged. The ash removal hoppers 7 of the e-filter 6 have the compressed air ash extractors 8 with the pipelines 9 and the compressed air generator 10 . The ash removal line 11 is integrated in the dry ash container 12 . The dry ash container 12 has the ash transport system 13 and the exhaust air-ash line 14 . The exhaust air-ash line 14 is integrated into the wet separator 15 via the inlet chamber 16 and / or via the nozzle base 17 . The wet separator 15 is connected via the exhaust line 18 with the flue gas duct 5 to the e-filter 6 .

The overflow 19 of the scraper belt 3 is connected via the suction water line 20 , the pump 21 and the pressurized water line 22 to the nozzles 23 of the wet separator 15 . The wet separator of 15 has the control valve 24 , the water-ash line 25 is guided to the scraper belt 3 .

The mode of action is as follows:
The ash / slag 26 accumulating in the steam boiler 1 falls into the scraper belt 3 , where the ash / slag 26 is extinguished with water and disposed of via the wet ash belt 4 .

The dry ash 27 of the e-filter 6 is funneled in the deashing funnel 7 and passes by means of the transport air 28 as an ash-transport air mixture 35 via the deashing line 11 into the dry ash container 12 . The dry ash 27 is separated from the transport air 28 in the dry ash container 12 and disposed of via the ash transport system 13 . The exhaust air-ash mixture 29 reaches the wet separator 15 via the inlet chamber 16 and / or nozzle base 17 . The circulation water 30 is introduced via the nozzles 23 from above into the wet separator of FIG. 15 . Through the injected water and / or
Soil washing water separates the ash from the exhaust air and the resulting water-ash mixture 31 is passed into the scraper belt 3 and disposed of via the wet ash belt 4 . The overflow water 32 of the scraper belt 3 is sucked in with the supply water 33 by the pump 21 and injected into the wet separator 15 . The dust-free exhaust air 34 is introduced via the exhaust air line 18 into the flue gas duct 5 to the E-filter 6 .

The following advantages are achieved by the invention:

• 1. Environmentally friendly disposal of an exhaust air-ash mixture from a dry ash container
• 2. Compensating the pressure loss by integrating the dust-free exhaust air in the vacuum area after the E-filter
• 3. The system does not require any additional operating effort
• 4. The washing water or circulating water required does not need to be disposed of - circulating.

Reference list

1 steam boiler
2 ash funnels
3 scraper tape
4 wet ash tape
5 flue gas duct
6 e-filters
7 ash removal funnels
8 air purifiers
9 pipes
10 compressed air generators
11 Ash removal line
12 dry ash containers
13 Ash transport system
14 Exhaust air ash line
15 wet separators
16 inlet chamber
17 nozzle base
18 Exhaust duct
19 overflow
20 suction water pipe
21 pump
22 Pressurized water line
23 nozzles
24 control valve
25 water-ash pipe
26 ash / slag
27 dry ash
28 Transport air
29 Exhaust air-ash mixture
30 circulating water
31 water-ash mixture
32 overflow water
33 inlet water
34 exhaust air
35 Ash-transport air mixture
36 Inlet water pipe

Claims (8)

1. A method for disposing of an exhaust air-ash mixture from a dry ash container, characterized in that the exhaust air-ash mixture ( 29 ) and circulating water ( 30 ) in a wet separator ( 15 ) introduced, the resulting dust-free exhaust air ( 34 ) in the flue gas stream and the water-ash mixture ( 31 ) in the scraper belt ( 3 ) of the ash removal system of the steam boiler ( 1 ) is passed. 2. The method according to claim 1, characterized in that the exhaust air-ash mixture ( 29 ) is blown over different levels in the wet separator ( 15 ). 3. Arrangement for the disposal of an exhaust air-ash mixture from a dry ash container, characterized in that the exhaust air-ash line ( 14 ) of the dry ash container ( 12 ) is integrated into a wet separator ( 15 ) which has a pressurized water line ( 22 ), a Dust-free exhaust air line ( 18 ) and a water-ash line ( 25 ), the dust-free exhaust air line ( 18 ) connected to the flue gas duct ( 5 ) and the water-ash line ( 25 ) to the scraper belt ( 3 ) of the ash removal system of the Steam boiler ( 1 ) is guided. 4. Arrangement according to claim 3, characterized in that the exhaust air-ash line ( 14 ) is arranged on levels arranged in a run nozzle in the wet separator ( 15 ). 5. Arrangement according to claim 3 and 4 characterized in that the exhaust air-ash line ( 14 ) in inlet chambers ( 16 ) and / or a nozzle base ( 17 ) in the wet separator ( 15 ) is bound. 6. Arrangement according to claim 3, characterized in that the inlet water pipe ( 36 ) with the overflow ( 19 ) of the scratch tape ( 3 ) is connected. 7. Arrangement according to claim 3, characterized in that the pressurized water line ( 22 ) on the jacket and / or ceiling of the Naßab separator ( 15 ) is integrated. 8. Arrangement according to claim 7, characterized in that the pressurized water line ( 22 ) with in the wet separator ( 15 ) is arranged th nozzles ( 23 ).