Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
  • F23J15/00—Arrangements of devices for treating smoke or fumes
  • F23J15/02—Arrangements of devices for treating smoke or fumes of purifiers, e.g. for removing noxious material
  • F23J15/04—Arrangements of devices for treating smoke or fumes of purifiers, e.g. for removing noxious material using washing fluids
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24D—DOMESTIC- OR SPACE-HEATING SYSTEMS, e.g. CENTRAL HEATING SYSTEMS; DOMESTIC HOT-WATER SUPPLY SYSTEMS; ELEMENTS OR COMPONENTS THEREFOR
  • F24D2200/00—Heat sources or energy sources
  • F24D2200/16—Waste heat
  • F24D2200/18—Flue gas recuperation

Definitions

• the invention relates to a method for purifying exhaust gas and recovering heat, in particular from a combustion system, in which the exhaust gas is brought into contact with a circulating scrubbing liquid which contains additives which bind pollutants contained in the exhaust gas and oxidize the resulting compounds and be removed from the cycle.
• Firing systems in which fossil fuels are burned pollute the environment due to pollutants carried in the exhaust gas, in particular sulfur dioxide S0 2 .
• pollutants carried in the exhaust gas in particular sulfur dioxide S0 2 .
• the hot exhaust gases result in high heat losses. This heat loss means that the overall efficiency of a furnace, in which, for example, water is heated, is limited and the utilization of the energy used is therefore unsatisfactory.
• the washing liquid which is expediently circulated for this purpose contains corresponding chemicals, such as calcium carbonate and / or calcium oxide
• the compounds formed are then oxidized to calcium sulfate by oxygen and this is separated from the wash water and removed.
• the object of the invention is to provide a method of the type mentioned at the outset which is suitable for exhaust gas purification even in small and medium-sized incineration plants, with a minimum expenditure on apparatus, extensive washing out of the substances contaminating the exhaust gases and, at the same time, economical work through recovery ⁇ use of heat and corresponding energy-saving use of the fuels.
• the object of the invention also includes the creation of a device for optimal implementation of the method.
• the object is achieved by a method of the type mentioned at the outset in that the washing liquid is introduced from a storage container into an upper space of an exhaust pipe or a chimney of the combustion system and from here in counterflow to the exhaust gas flowing upwards in the exhaust pipe or chimney is directed, the pollutants bound by the additives present in the washing liquid and the compounds formed
• the device for carrying out the method is characterized in that an exhaust pipe, starting from a boiler room of a boiler of the furnace, which is heated by a burner, is pulled upwards through a chimney, one by one next to the exhaust pipe
• Storage tank containing washing liquid outgoing line is led up to an upper region of the exhaust gas line and here opens into this, and a drain line is provided in a lower region of the exhaust gas line, which leads back into the storage tank.
• the method has a number of advantages, which range from being carried out in a space-saving arrangement for small and medium-sized systems to removing pollutants and simultaneously utilizing heat.
• One of the essential features is the inclusion of the fireplace in the work area of the washing process.
• the space requirement of the entire system is thus reduced to a minimum, and it is also achieved that at the same time not only pollutants but also heat is removed from the exhaust gas by the washing liquid flowing in the counterflow, which heat can now be supplied to a fluid to be heated.
• the one Device adapted to the method offers yet another possibility for heat utilization, which can be implemented without great effort.
• a heat exchanger In a connecting line, for example a chimney socket between the boiler and the flue pipe in the chimney, a heat exchanger can be installed which already extracts part of the heat that is usually lost from the useful heat due to the flue gas flowing out here, so that this heat ⁇ can be used for a purpose.
• the additional device consisting of a combined storage sedimentation tank and optionally reaction tank has further advantages since the solid compounds washed out with the washing water and formed by the further treatment settle during the burner's standstill periods. When the burner is out of operation, the washing liquid circulation is also switched off. The fine solids, because they are generally such, settle out of the still washing liquid in the storage container and are only sporadically removed from here during the downtimes.
• the separation is more complete than with a removal of the solids during the liquid circulation, as is the case with known methods and systems.
• This measure also simplifies and improves the method according to the invention compared to the prior art.
• the amount of heat extracted from the scrubbing liquid is regulated in such a way that the temperature of the liquid is partly below and partly above the dew point of the flue gases or exhaust gases. In this way, moisture from the exhaust gases is condensed into the wash water on the one hand and water from the wash water is evaporated into the smoke or exhaust gases on the other hand.
• the amount of heat extracted from the washing liquid via heat exchangers is expediently regulated by means of a level switch assigned to the storage tank, and thus the temperature and the amount of the washing liquid are controlled. As a result, the circuit is maintained at a substantially certain level and careful dosing of the to
• c .. Fig. 1 is a schematic elevation of one between
• Boiler of a combustion system and a storage container for washing liquid arranged device Boiler of a combustion system and a storage container for washing liquid arranged device
• Fig. 2 is a schematic elevation of a storage container connected to the device, which is simultaneously designed as a sedimentation and reaction container.
• the boiler 1 schematically shows a conventional oil burner 1 of a firing system arranged in a boiler 2, which is followed by the washing system.
• the boiler 2 which is used, for example, for heating domestic and heating water, is equipped with a domestic water supply 3 and a domestic water feed line 4 as well as a heating supply 5 and a heating return 6.
• the boiler 2 is connected to a chimney 8, which is brick, but can also be designed only as a jacket for an exhaust pipe 9.
• This exhaust pipe 9 is an essential part of the device for carrying out the washing process. It leads upwards from the lower region of the chimney 8, preferably essentially through the entire length of the chimney 8, and the exhaust gases from the oil burner 1 flow through it.
• a storage container 16 is provided outside the chimney 8, expediently at its lower end, from which a line 12 for the
• Wash water opens into an upper area in the exhaust pipe 9.
• a pump 13 is installed in the line 12 and then an air injector 15 is installed thereon.
• the entry of the line 12 into the exhaust line 9 is preferably with a
• spray device 10 which advantageously has spray arms 11 arranged in a star shape.
• a drain line 14 leads back to the storage container 16 from a lower area of the exhaust gas line 9, which area is closed to the outside. The washing liquid is injected from the storage container 16 into the exhaust pipe 9 with the aid of the pump 13
• a practical embodiment provides an exhaust pipe 9 with a length corresponding at least to the chimney height, advantageously 6 m or more.
• the diameter of such an exhaust pipe 9 is approximately 15 cm.
• Washing liquid which binds pollutants in the exhaust gas is preferably a lime solution in which burnt lime and water are present in a ratio of 40 g of lime to 1 liter of water and formic acid in a ratio of 50 g of formic acid to 40 g of lime.
• Air is introduced into the wash water downstream of the pump 13 in the line 12, for example through the air injector 15, in order to carry out the required oxidation in the solution.
• the process water feed 17 is passed through the storage tank 16 and passes into the process water feed line 4, which enters the boiler 2.
• the return 18 of the heating water also leads through the storage tank 16 and from here to the heating return 6, which opens into the boiler 2.
• a heat exchanger 7 is used, which is already at the entrance the exhaust gases coming from the boiler 2 remove this heat.
• the medium heated in the heat exchanger can be used for any purpose.
• the design of the storage container 9 also contributes to the optimal implementation of the method according to the invention, which can be designed in such a way that not only the washing liquid is stored here, but the solids fall down and are collected therein during the shutdown of the firing system .
• this storage container 16 can also be equipped with a reaction chamber.
• a combined storage, sedimentation and reaction container 16 is shown schematically in FIG.
• the boiler 2 of the combustion system and the chimney 8 in which the exhaust pipe 9 (FIG. 1) is guided and into which the pipe 12 for the washing liquid coming from the storage tank 16 opens are shown here.
• the storage, sedimentation and reaction container 16 consists of three compartments, namely the chamber 20 for the washing liquid flowing back from the exhaust pipe 9 via the drain pipe 14. Below this chamber 20 is the sludge chamber 21 and above the chamber 20 there is a storage chamber 22 filled with calcium carbonate (CaC0 2 ). In the chamber 20 there is a heat exchanger 23, for example for process water, into which the inlet or outlet Lead outlet lines 17, 18 for a medium that is used for heat recovery.
• the pump 13 is arranged in the lower region of the line 12 for the washing water leading into the exhaust gas line 9 and is followed by the air injector 15.
• the combined storage, sedimentation and and reaction container is assigned a level switch LIS, which, as already mentioned, is provided for regulating and controlling the flow of the medium for heat recovery.
• the setting is such that the temperature of the washing liquid is partly below and partly above the dew point of the exhaust gases, so that either moisture from the exhaust gases condenses into the washing water or water from the washing water evaporates into the exhaust gases. Level switches of this
• the exhaust gas generated in the oil burner 1 contains S0 2, which is known to produce up to about 3 liters of S0 2 ⁇ gas when burning 1 Kg l. This sulfur gas, which pollutes the environment, should and must be removed.
• the exhaust gas flowing through the chimney nozzle 19, which is hot up to about 300 ° C., is first cooled by the heat exchanger 7 located in this feed line. This is preferably designed such that the exhaust gas is cooled to, for example, 50 to 80 ° C. At this temperature, the exhaust gas reaches the exhaust gas line 9.
• the heat exchanger 7 can be flowed through by water which heats up by heat exchange and this warm water can be used for various purposes, such as for building heating, domestic water heating, swimming pool heating and the like .
• the exhaust gas cooled in the first heat exchanger 7 flows upward in the exhaust gas line 9, counter to the washing liquid which contains a calcium format and flows through the spray device 10 from top to bottom in the exhaust gas line 9. During this counterflow, the sulfur dioxide contained in the exhaust gas reacts with the Ca ions of the scrubbing liquid. According to the Ca2 + - bound by the sulfur dioxide
• Ions form free formic acid.
• this free formic acid reacts with the calcium carbonate in the storage space 22.
• Calcium carbonate Ca 2+ ions dissolved, so that a regenerated washing solution is supplied to the exhaust line 9.
• a detergent funnel 25 ⁇ Fig. 2 provided, from which the scrubbing liquid enriched with bound sulfur dioxide from the exhaust gas reaches the chamber 20 of the combined storage container 16 via the drain line 14.
• the sludge layer is expediently covered by a cover funnel 24 in relation to the rest of the container space in order not to whirl up any settled sludge during the washing liquid circulation.
• the settled solid can be drawn off at the bottom of the sludge chamber 21 in corresponding periods.
• c_.: ⁇ exchange in two stages, namely before the washing process and during the washing process, can be recovered and used. Finally, the washing liquid can also be regenerated in whole or in part.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Treating Waste Gases (AREA)
• Central Heating Systems (AREA)
• Steam Or Hot-Water Central Heating Systems (AREA)
• Exhaust Gas Treatment By Means Of Catalyst (AREA)
• Filling Or Discharging Of Gas Storage Vessels (AREA)
• Separation By Low-Temperature Treatments (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=4215347

Family Applications (1)

Country Status (6)

Families Citing this family (11)

Citations (6)

Family Cites Families (6)

• 1982
  • 1982-05-04 DE DE19823216561 patent/DE3216561A1/de not_active Withdrawn
• 1983
  • 1983-03-12 AT AT83102457T patent/ATE20493T1/de not_active IP Right Cessation
  • 1983-03-12 EP EP83102457A patent/EP0089036B1/de not_active Expired
  • 1983-03-12 DE DE8383102457T patent/DE3364139D1/de not_active Expired
  • 1983-03-12 WO PCT/DE1983/000048 patent/WO1983003295A1/en unknown
  • 1983-08-02 NO NO832788A patent/NO832788L/no unknown
  • 1983-11-16 DK DK524083A patent/DK524083A/da not_active Application Discontinuation

Patent Citations (6)

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