Abstract: The invention relates to a device (2) and a method for supplying combustion air and for recirculating exhaust gas for a burner (1) comprising a combustion chamber (10) and to a burner (1) comprising a device (2) for supplying combustion air and for recirculating exhaust gas. Multiple drive nozzles (21) distributed about a central axis (A) are used to supply combustion air to a mixing chamber (22) arranged downstream of the drive nozzles (21) by suctioning exhaust gases out of the combustion chamber (10); the combustion air exiting the drive nozzles (21) is mixed with exhaust gases in the mixing chamber (22) in order to form a combustion air/exhaust gas mixture, said exhaust gases flowing out of the combustion chamber (10) and being backflushed by means of the drive nozzles (21); and the combustion air/exhaust gas mixture is supplied to a reaction zone downstream of the mixing chamber (22).

Abstract: The invention relates to a flat tube heat exchanger, in particular to a high-temperature flat tube heat exchanger for gaseous media, comprising a closed housing (5) having a tube bundle space (50) and a tube bundle, arranged in the tube bundle space (50) of the housing (5), comprising multiple flat tubes (2), there being arranged, in the flat tubes (2) and in the tube bundle space (50) between the flat tubes (2), corrugated strips (3, 6) having peaks (30, 60) and troughs (31, 61) extending in the longitudinal direction of the flat tubes (2), wherein the peaks (30, 60) and troughs (31, 61) respectively bear internally and externally against flat sides (200) of the flat tubes (2), and wherein there is provided a device for externally applying a surface pressure to the housing (5), at least in the region of the tube bundle space (50), this pressure being higher than a pressure (p1, p2) of the media guided in the flat tubes (2) or around the flat tubes (2).

Abstract: A process and apparatus for gasification of biomass. Biogenic residue may be supplied to a heating zone to dry the biomass and allow the volatile constituents to escape to generate a pyrolysis gas. The pyrolysis gas is supplied to an oxidation zone and substoichiometrically oxidized to generate a crude gas. The carbonaceous residue generated in the heating zone and the crude gas is partially gasified in a gasification zone. The gasification forms activated carbon and a hot process gas. The activated carbon and the hot process gas are conjointly cooled. The adsorption process during the conjoined cooling has the result that tar from the hot process gas is absorbed on the activated carbon in the cooling zone. A pure gas which is substantially tar-free is obtained. The tar-enriched activated carbon may be at least partly burned for heating the heating zone and/or the gasification zone.

Abstract: A method for heating a heating chamber to a temperature below the spontaneous ignition temperature of the fuel that is used, wherein fuel and air are reacted in flameless oxidation in a non-stoichiometric mixture ratio in a combustion chamber. The air ratio ? is at least lower than the stoichiometric ratio ?=1 such that the temperature in the combustion chamber does not exceed the temperature at which thermal nitrous oxide generation begins. Otherwise, ? is established such that the spontaneous ignition temperature of the fuel is exceeded. This results in two permissible air ratio ranges, between ?min and ?1 in sub-stoichiometric operation, and ?2 to ?max in superstoichiometric operation of the combustion chamber. The still-reactive gases released from the combustion chamber are made to react in the heating chamber, preferably by flameless oxidation. This avoids thermal nitrous oxide generation in the heating chamber.

Abstract: This flat tube heat exchanger encompasses a closed housing, in which two tube sheets and a tube bundle, which is arranged between the tube sheets and which is supported by the tube sheets is arranged. The tube bundle comprises at least some flat tubes, which extend in longitudinal direction of the tube bundle. At their ends, the flat tubes are round and are flat in a central section. The ends of the flat tubes, which have a round cross section, can be circular or can encompass a different round shape.

Abstract: To heat a furnace chamber (16) indirectly using radiant tubes (11) to (14), heating energy is transferred through the radiant tube wall into the furnace chamber (16). During steady-state operation, the temperature in the radiant tube (11) to (14) and on its surface is higher than the furnace, depending on the specific heat output of the radiant tube (11) to (14). At a furnace temperature of 770° C. and a heat output of 50 kW/m2, the radiant tube has a temperature of 900° C. The radiant tube (11) to (14) can thus operate continuously with flameless oxidation at this output, even though the temperature in the furnace is only 100° C. However, if the radiant tube (11) to (14) has cooled to the furnace temperature of 770° C. during a break in burning, deflagration is avoided when the associated burner is ignited by initially operating said burner with a flame for a few seconds.

Abstract: A burner system includes at least one radiant heating tube (22) and a first regenerator (48) disposed at a first end (24) of the tube. A second regenerator (50) is disposed at a second end (26) of the radiant heating tube (22). The first regenerator (48) and the second regenerator (50) are connected to a valve system (54) having first and second operating states for alternately supplying the radiant heating tube (22) with combustion air via one regenerator (48, 50) and for discharging exhaust gases via the other regenerator (48, 50). At least one inner tube (34) is disposed inside and extending along the radiant heating tube (22) at least in sections. The inner tube (34) is connected to a fuel supply line (76) and has outlet openings (46) provided along the longitudinal extension of the inner tube (34).

Abstract: A process and apparatus for gasification of biomass. Biogenic residue may be supplied to a heating zone to dry the biomass and allow the volatile constituents to escape to generate a pyrolysis gas. The pyrolysis gas is supplied to an oxidation zone and substoichiometrically oxidized there to generate a crude gas. The carbonaceous residue generated in the heating zone and the crude gas is partially gasified in a gasification zone. The gasification forms activated carbon and a hot process gas. The activated carbon and the hot process gas are conjointly cooled. The adsorption process during the conjoined cooling has the result that tar from the hot process gas is absorbed on the activated carbon in the cooling zone. A pure gas which is substantially tar-free is obtained. The tar-enriched activated carbon may be at least partly burned for heating the heating zone and/or the gasification zone.

Abstract: A recuperative burner (10) fires a furnace chamber (11) in a substoichiometric manner. The recuperative burner is arranged in a radiant tube (26) which is open towards and protrudes into the furnace chamber. Together with the recuperator (18) or a protrusion (21), the radiant tube (26) forms an exhaust gas channel (19) into which burn-out air is introduced by an air conducting device (23). The post-combustion which occurs in the exhaust gas channel (19) heats the radiant tube (26). The furnace chamber (11) is heated partly directly by fuel and air and partly indirectly by the radiant tube (26). An excessive level of CO emission is prevented by the post-combustion in the exhaust gas channel (19). By using the resulting heat from the radiant tube (26), excessively high exhaust gas temperatures are prevented and the thermal use of the fuel is optimized.

Abstract: To heat a furnace chamber (16) indirectly using radiant tubes (11) to (14), heating energy is transferred through the radiant tube wall into the furnace chamber (16). During steady-state operation, the temperature in the radiant tube (11) to (14) and on its surface is higher than the furnace, depending on the specific heat output of the radiant tube (11) to (14). At a furnace temperature of 770° C. and a heat output of 50 kW/m2, the radiant tube has a temperature of 900° C. The radiant tube (11) to (14) can thus operate continuously with flameless oxidation at this output, even though the temperature in the furnace is only 100° C. However, if the radiant tube (11) to (14) has cooled to the furnace temperature of 770° C. during a break in burning, deflagration is avoided when the associated burner is ignited by initially operating said burner with a flame for a few seconds.

Abstract: To improve the efficiency of recuperator burners, preferably to over 80%, a recuperator burner (10) is equipped with an auxiliary heat exchanger (26) which surrounds the recuperator (22), wherein both the recuperator and the auxiliary heat exchanger are preferably formed as purely counterdirectional-flow heat exchangers, wherein the auxiliary heat exchanger (26) has the air supplied to it on the side facing toward the furnace wall (11). The housing (15) around the auxiliary heat exchanger (26) can be cooled with cool air from the inside. In one configuration, the air is initially conducted to a flange cooler (45) to protect the region of the flange (16) against the exhaust-gas temperature. For example, the ceramic recuperator pipe (26) is resiliently pressed, and sealed off, against an outlet-side surface (35) of the auxiliary heat exchanger (26), which preferably has gap-like air ducts (39) formed in flattened pipes (40).

Abstract: A burner system includes at least one radiant heating tube (22) and a first regenerator (48) disposed at a first end (24) of the tube. A second regenerator (50) is disposed at a second end (26) of the radiant heating tube (22). The first regenerator (48) and the second regenerator (50) are connected to a valve system (54) having first and second operating states for alternately supplying the radiant heating tube (22) with combustion air via one regenerator (48, 50) and for discharging exhaust gases via the other regenerator (48, 50). At least one inner tube (34) is disposed inside and extending along the radiant heating tube (22) at least in sections. The inner tube (34) is connected to a fuel supply line (76) and has outlet openings (46) provided along the longitudinal extension of the inner tube (34).

Abstract: A radiant heat tube (5) comprises a tube body having a center section (6) and at least one recirculating section (7, 8) arranged next to the center section, said recirculating section forming a loop (9, 10) with said center section. A pivot joint bearing (23) is arranged on one end (12) of the radiant heat tube, while a sliding bearing (15) is arranged on the other end (11) of the radiant heat tube, said sliding bearing (15) being arranged opposite said pivot joint bearing (23). A burner (14) is disposed to heat the radiant heat tube (5).

Abstract: To improve the efficiency of recuperator burners, preferably to over 80%, a recuperator burner (10) is equipped with an auxiliary heat exchanger (26) which surrounds the recuperator (22), wherein both the recuperator and the auxiliary heat exchanger are preferably formed as purely counterdirectional-flow heat exchangers, wherein the auxiliary heat exchanger (26) has the air supplied to it on the side facing toward the furnace wall (11). The housing (15) around the auxiliary heat exchanger (26) can be cooled with cool air from the inside. In one configuration, the air is initially conducted to a flange cooler (45) to protect the region of the flange (16) against the exhaust-gas temperature. For example, the ceramic recuperator pipe (26) is resiliently pressed, and sealed off, against an outlet-side surface (35) of the auxiliary heat exchanger (26), which preferably has gap-like air ducts (39) formed in flattened pipes (40).

Abstract: In a burner and method for the operation of such a burner which is provided with first fuel and air supply means for FLOX® operation and second fuel and air supply means for operation with flame combustion, a control unit is provided for controlling fuel and air supply means in such a manner that, aided by flame combustion operation, the temperature required for FLOX® operation is rapidly achieved and FLOX® operation can be maintained at least in the region directly in front of the burner so as to provide for assisted FLOX® operation of the burner already before the conditions for pure FLOX® operation are established.

Abstract: This flat tube heat exchanger encompasses a closed housing, in which two tube sheets and a tube bundle, which is arranged between the tube sheets and which is supported by the tube sheets is arranged. The tube bundle comprises at least some flat tubes, which extend in longitudinal direction of the tube bundle. At their ends, the flat tubes are round and are flat in a central section. The ends of the flat tubes, which have a round cross section, can be circular or can encompass a different round shape.

Abstract: In a highly efficient recuperator burner, which comprises at least one combustion chamber for warm-up operation and is otherwise set up for FLOX® operation, and a recuperator for preheating combustion air by means of thermal exhaust gas energy in a counter-current heat exchange mode via heat exchanger pipes, each heat exchanger pipe has, in a heat exchange section thereof, a flattened gap cross-section and, at its end facing a volume to be heated, a nozzle cross-section, which differs from the flattened gap cross-section of the heat exchanger pipe.

Abstract: In a high efficiency regenerator burner for heating spaces, the exhaust gas generated by the burner is provided which is conducted alternately through different regenerator cartridges and a partial stream of the exhaust gas is conducted under the control of an orifice plate through a bypass space in which the regenerator cartridges are disposed. A control structure is disposed in a burner head for controlling the exhaust gas bypass flow volume and also to control the main exhaust gas flow as well as the combustion air flow through the regenerator cartridges.

Abstract: The fuel cell system in accordance with the invention is used for the generation of current and heat from liquid and gaseous fuels. Said system comprises a reformer and a fuel cell stack having an operating temperature above 120° C. and providing exhaust heat that is utilized for the generation of steam in the evaporation channels (2). The evaporation channels (2) are arranged so as to be in direct thermal contact with the stack (1) that is to be cooled. A pressure-maintaining device at the outlet of the evaporation channels (2) is disposed to adjust the pressure in said channels to a value that results in the desired stack temperature.

Abstract: The fixed-bed gasifier and method in accordance with the invention operates with a solid material batch that is perfused by air and/or steam in opposing direction. Compared with the resultant pyrolysis coke batch, the actual pyrolysis zone is thin enough so as to result in a material dwell time in the pyrolysis zone of only a few minutes, while the dwell time of the pyrolysis coke in the pyrolysis coke layer may last up to several hours. The pyrolysis occurs in an allothermic manner. High-energy low-dust and low-tar gas is formed. The process control can be automated in a reliable manner. The exhaust of reaction gases and pyrolysis gases occurs through the heating chamber, whereby the last tar components are eliminated.