AU651872B2

AU651872B2 - Drying of hydrous solid fuels, in particular raw brown coal

Info

Publication number: AU651872B2
Application number: AU12352/92A
Authority: AU
Inventors: Bernd Krodel
Original assignee: VEAG Vereinigte Energiewerke AG
Current assignee: VEAG Vereinigte Energiewerke AG
Priority date: 1991-02-15
Filing date: 1992-02-13
Publication date: 1994-08-04
Anticipated expiration: 2012-02-13
Also published as: EP0639215B1; EP0639215A1; AU1235292A; WO1992014801A1; DE59206258D1; JPH07507332A; DE4105129A1

Description

OPI DATE 15/09/92 AOJP DATE 29/10/92 APPLN. ID 12352 92* o PCT NUMBER PrT/DE92/no01f5 vESENS (PCT) (51) Internationale Patentklassifikation 5 (11) Internationale Veriiflentlichungsnummer: WNO 92/14801 CI OF 5100, F01lK 17/06 Al (43) Internationales Veriiffentlichungsdatum: 3. September 1992 (03.09.92) (21) Internationalcs Aktenzeichen: PCT/DE92/O00105 Veriiffentlicht Mit internationalen RecIherchenbericlii.

(22) Internationales Anmeldedaturn: 13. Februar 1992 (13.02.92) Prioritiitsdaten: P 41 05129,7 15. Februar 1991 (15.02.91) DE 617 (71) Aunelder: VEAG VEREINIGTE ENERGIEWERKE AK- TI ENGES ELLSC HAFT [DE/DE]; Allee der Kosmonauten 29, D-I 1140 Berlin (DE).

(74) Anwalt: ZINKEN-SOMMER, Rainer; VEAG Vereinigte Energiewerke Aktiengesellschaft, Referat Patent- und Lizenzwesen, Allee der Kosmonauten 29, D-l 1140 Berlin

(DE).

(81) Bestimmungsstaaten: AT (europiiisches Patent), AU, BE (europiisches Patent), BG, CA, CH (europflisches Patent), DE (europdiisches Patent), DK (europiisches Patent), ES (europflisc'hes Patent), FR (europiiisches Patent), GB (europflisches Patent), GR (europllisches Patent), HU, IT (europflisches Patent), JP, LU (europaiisches Patent), MC (europfiisches Patent), NL (europflisches Patent), RO, RU, SE (europfiisches Patent).

(54)Title: PROCESS FOR DRYING HYDROUS SOLID FUELS, IN PARTICULAR RAW BROWN COAL (54)Bezeichnung: VERFAHREN ZUR TROCKNUNG WASSERHALTIGER FESTER BRENNSTOFFE, INSBESONDE- RE ROHBRAUNKOHLE (57) Abstract The invention concerns a process for drying hydrous solid fuels, in particular raw brown coals, in a drying container of a heat-generating plant. The aim of the invention is to achieve substantial reduction I of the CO,) emission per useful effect unit by reduced use of fossil energy carriers; the devices for drying raw brown coal are to be con--- nected to the heat-generating installation in such a manner that the 0~ energy of the exhaust vapours is fully utilized. According to the invention, this is achieved by virtue of the fact that the drying container is heated directly by a saturated steam circuit of the heating boiler of the steam-generatinL. Aant, the dust-free exhaust vapours under average pressure are fed to a heat supply line and the exhaust va- Fpour condensate is used, following chemical processing, to supply water to a heating plant and/or a heating network.

(57) Zusanimenfassung Die Erfindung betrifft emn Verfahren zur Trocknung wasserhaltiger fester Brennstoffe, insbesondere Rohbraunkohle, in einem Trocknungsbehfilter ciner W~irmeerzeugungsanlage. Der Erfindung liegt die Aufgabe zugrunde, eine deutliche Reduzierung der C0 2 )-Emission je Nutzleistungseinheit dlurch verringerten Einsatz fossiler Energietrifiger zu erreichen, wobei die Trocknungseinrichtungen fOr Rohibraunkohle so mit der Wilrmeerzeugungsanlage verbunden werden, dag cine vollstilindige energetische Verwertung des Brildens realisiert wird, Dies wird erfindungsgenig dadurch erreicht, daA der Trocknungsbehfilter Ober einen eigenen Sattdampfkreislauf vom Heizkessel der Dam pferzeugu ngsanlage direkt erhitzt, der entstaubte und unter Mitteldruck stehende BrOden auf eine Wilrmeversorgungsschiene gegeben und das Br~denikondenzat nach dessen chemnischer Aufbereitung zur Wasserversorgung eines Heizwverkes und/oder eines Heiznetzes eirgesetzt wird.

1- PROCESS TO DRY HYDROUS SOLID FUELS, IN PARTICULAR RAW BROWN COAL The invention concerns a process for etrying hydrous solid fuels, in particular raw brown coal, in a drying vessel of a heat generating plant.

A plant arrangement to dry raw coal prior to its use for generating electricity in condensation power plants is known. This known arrangement enables to fully utilise the condensation heat of the exhaust vapour but neither an exhaust vapour reverse compression nor a separate electric exhaust vapour dedusting is carried out. The drying of the raw coal is carried out in a filled shaft reactor provided with diaphragm tube walls which act as heating surfaces. Bleed steam from the main turbine of the power plant is used as heating steam and supplied to the filled shaft reactor. The exhaust vapour obtained therefrom is dedusted at the exit into the exhaust vapour channel, i.e. when leaving the dryer, by means of a filter wall which can be steam cleaned (DD-PS 281 237). As described in DD-PS 281 237, the energy of the exhaust vapour is fully utilised as secondary energy only in that it is divided into several and qualitatively different applications; this requires a complicated integration of different appliances into the overall conception of the plant. In addition, the known arrangement is intended exclusively for power plants in which the generation of electricity is effected in "pure" condensation operation only.

It would thus be beneficial if the present invention could achieve a considerable reduction of the CO 2 emission per effective power output unit of a power generating plant by using smaller amounts of fossil energy carriers. Heretofore, it would be advantageous to integrate the drying devices for the raw brown coal into 5 the heat generating unit in such a manner that the energy S:17950E/12.494 2 of the exhaust vapour is fully utilised.

In a preferred form, the present invention provides a process for drying hydrous solid fuels, in particular raw brown coal, in a drying vessel of a heat-steam generating plant, wherein the exhaust vapour of the drying vessel is condensed, expanded and treated, characterised by directly heating the drying vessel from a heating boiler of the steam generating plant via its own saturated steam circuit, by conveying the dedusted exhaust vapour, which is under medium pressure, to a heat supply line, by condensing the exhaust vapour, by chemically treating the exhaust vapour condensate, and by utilising the treated exhaust %rapour condensate as water supply for the heat generating plant and/or for a heating network.

The invention will be explained in detail below based on an embodiment thereof and with reference to the accompanying drawing, in which: Fig. 1 shows in a schematic arrangement a heating S 20 house for raw brown coal with separate coal drying.

The drying vessel 1 shown in Fig. 1 is equipped with a heating surface bundle 2 and is connected via pipeline 3 and conveying device 4 with the steam boiler 5. The drying vessel 1 and the steam boiler 5 have a common or own saturated steam circuit 6. The exhaust vapour produced in the drying vessel 1 is supplied via pipeline 7 to the heating water pre-heater 8 and via an expander 9 and an exhaust vapour treatment unit 10 to the water supply of the steam vessel 5 and/or to the water supply of a heating network 11.

The advantages of the invention are: the illustrated inventive circuitry enables a r e reduction of C0 2 -formation and consequently C0 2 -emission S :17950/12.4.94 3 from the heat generating plant while otherwise effecting the same effective power output therefrom; a further advantage is a reduction in use of additives for retaining SO 2 from the exhaust gases and consequently a reduction of accumulated ash and waste product accumulation in the power plant; furthermore, there is the possibility of utilising the exhaust vapour condensate to provide a water supply for an appliance of the heat (and power) generating plant, namely the heating boiler.

'4/ S:17950E/12.4.94

Claims

1. Process for drying hydrous solid fuels, in particular raw brown coal, in a drying vessel of a heat/steam generating plant, wherein the exhaust vapour of the drying vessel is condensed, expanded and treated, characterised by directly heating the drying vessel from a heating boiler of the steam generating plant via its own saturated steam circuit, by conveying the dedusted exhaust vapour, which is under medium pressure, to a heat supply line, by condensing the exhaust vapour, by chemically treating the exhaust vapour condensate, and by utilising the treated exhaust vapour condensate as water supply for the heat generating plant and/or for a heating network.

2. Process for drying hydrous solid fuels as hereinbefore described with reference to wigure 1. DATED this 12th day of April 1994 VEAG VEREINIGTE ENERGIEWERKE AKTIENGESELLSCHAFT By their Patent Attorneys GRIFFITH HACK CO S:17950E/12,4.94 Abstract The invention concerns a process to dry hydrous solid fuels, in particular raw brown coal, in a drying vessel of a heat generating plant. The object of the invention is to achieve a considerable reduction of the CO 2 emission per actual output unit by reduced use of fossil energy carriers, wherein the drying devices for the raw brown coal are connected with the heat generating plant in such a manner that a complete energy utilisation of the exhaust vapour is realised. According to the invention this will be achieved by that the drying vessel is directly heated from the heating boiler of the steam generating plant over its own saturated steam circuit, the dedusted exhaust vapour which is under medium pressure is conveyed to a heat supply rail and the exhaust vapour condensate, after a chemical treatment, is used for the water supply of a heating plant and/or of a heating network.