Abstract: A method for calcining and cooling material such as carbonate rocks may be employed in a parallel-flow regenerative shaft kiln that has two shafts, which are operated alternately as a calcining shaft and as a regenerative shaft. Material flows through a preheating zone, a calcining zone, and a cooling zone to a product outlet. At least one gas flow is compressed by a high-pressure fan and introduced into the parallel-flow regenerative shaft kiln. The high-pressure fan is configured as an axial fan or as a radial fan, having an impeller through which flow takes place axially or radially. A parallel-flow regenerative shaft kiln may also be utilized to perform such methods.

Abstract: A shaft furnace for firing carbonate-containing material may include, in a flow direction of the material, a preheating zone, a firing zone, a cooling zone, and a material outlet for discharging the material from the shaft furnace. Burner lances project into the firing zone. At least one burner lance has a first penetration depth into the firing zone and at least one further burner lance has a second penetration depth into the firing zone that is greater than the first penetration depth. A primary air conduit may be configured to convey combustion air and may be connected to at least one burner lance. An oxygen conduit for conveying oxygen into the firing zone may be arranged such that oxygen flows from the oxygen conduit at least one burner lance having the second penetration depth.

Abstract: A method can be used to burn and cool material in a parallel flow-counter flow regenerative shaft kiln having two shafts that are operated alternately as a burning shaft and a regenerative shaft. The material flows through a preheating zone, a burning zone, and a cooling zone to a material outlet. Fuel is supplied in or above the preheating zone, and thus fuel is heated in the preheating zone prior to entering the burning zone. Further, a parallel flow-counter flow regenerative shaft kiln for burning and cooling material may have two shafts that can be operated alternately as a burning shaft and a regenerative shaft. Each shaft has, in a flow direction, a preheating zone for preheating material, a burning zone for burning material, and a cooling zone for cooling material. A fuel inlet that admits fuel into each shaft is arranged above or inside the preheating zone.

Abstract: A shaft furnace for firing carbonate-containing material may include, in a flow direction of the material, a preheating zone, a firing zone, a cooling zone, and a material outlet for discharging the material from the shaft furnace. Burner lances project into the firing zone. At least one burner lance has a first penetration depth into the firing zone and at least one further burner lance has a second penetration depth into the firing zone that is greater than the first penetration depth. A primary air conduit may be configured to convey combustion air and may be connected to at least one burner lance. An oxygen conduit for conveying oxygen into the firing zone may be arranged such that oxygen flows from the oxygen conduit at least one burner lance having the second penetration depth.

Abstract: A method of operating a plant having a furnace including at least two vertical shafts connected by an overflow duct, wherein at least one burner is arranged above the overflow duct in each case such that the burner gases therefrom flow downward in burning operation of the respective shaft. A cooling gas supply is provided beneath the overflow duct in each case such that, in combination with the operation of a burner in the burner-operated shaft, the burner gas flowing downward is deflected in the direction of the overflow duct by the cooling gas ascending in the burner-operated shaft, and a supply of cooling gas is adjusted such that the temperature of the burner charge through which the burner gas flows at least in the burner-operated shaft is kept above the deacidification temperature thereof.

Abstract: A furnace may include at least two vertical shafts, each of which may have at an upper end thereof an inlet for material to be burnt and at a lower end thereof a burnt material outlet. The inlet and the outlet may be connected by a transfer channel. In each case, at least one main burner may be positioned above the transfer channel, and a cooling gas inlet may be positioned below the transfer channel. At least one additional burner may be positioned below the transfer channel in each of the shafts. Such a furnace can be operated such that the material to be burnt in the currently fired shaft is at least partially calcined in a main burning zone above the transfer channel, and then thermally aftertreated in an additional burning zone positioned between the transfer channel and the additional burner.

Abstract: A furnace may include at least two vertical shafts, each of which may have at an upper end thereof an inlet for material to be burnt and at a lower end thereof a burnt material outlet. The inlet and the outlet may be connected by a transfer channel. In each case, at least one main burner may be positioned above the transfer channel, and a cooling gas inlet may be positioned below the transfer channel. At least one additional burner may be positioned below the transfer channel in each of the shafts. Such a furnace can be operated such that the material to be burnt in the currently fired shaft is at least partially calcined in a main burning zone above the transfer channel, and then thermally aftertreated in an additional burning zone positioned between the transfer channel and the additional burner.

Abstract: Burning and cooling carbonate rock in cocurrent regenerative lime kilns may involve alternately operating two shafts such that a first shaft operates as a burning shaft and a second shaft operates as a regenerative shaft during a first period and such that the first shaft operates as the regenerative shaft and the second shaft operates as the burning shaft during a second period. Carbonate rock introduced to upper regions of the shafts may be preheated and calcined. The carbonate rock may then be cooled in lower regions of the shafts before being discharged through discharge devices. The cooling of the carbonate rock may comprise introducing cooling air into the shafts partially through central displacement bodies in the shafts and partially through the discharge devices. Amounts of air entering through the central displacement bodies compared to the discharge devices may vary widely from the burning shaft to the regenerative shaft.

Abstract: A method of operating a plant having a furnace including at least two vertical shafts connected by an overflow duct, wherein at least one burner is arranged above the overflow duct in each case such that the burner gases therefrom flow downward in burning operation of the respective shaft. A cooling gas supply is provided beneath the overflow duct in each case such that, in combination with the operation of a burner in the burner-operated shaft, the burner gas flowing downward is deflected in the direction of the overflow duct by the cooling gas ascending in the burner-operated shaft, and a supply of cooling gas is adjusted such that the temperature of the burner charge through which the burner gas flows at least in the burner-operated shaft is kept above the deacidification temperature thereof.

Abstract: A method for burning lumpy stock is performed in at least one shaft which comprises a preheating zone, a burning zone and a cooling zone. Coal with a swelling index >1 is supplied together with a transport medium via burner lances which have burner tips. The coal together with the transport medium emerges into the shaft, wherein the temperature of the coal in the burner lances is kept below a temperature value at which melt phases of the coal that is used are formed. Here, for the transportation of the coal, use is made of a transport medium which, in the shaft, in the region directly adjacent to the burner tip, forms an oxygen-depleted atmosphere in order to delay the ignition of the coal after it emerges from the burner lance.

Abstract: Burning and cooling carbonate rock in cocurrent regenerative lime kilns may involve alternately operating two shafts such that a first shaft operates as a burning shaft and a second shaft operates as a regenerative shaft during a first period and such that the first shaft operates as the regenerative shaft and the second shaft operates as the burning shaft during a second period. Carbonate rock introduced to upper regions of the shafts may be preheated and calcined. The carbonate rock may then be cooled in lower regions of the shafts before being discharged through discharge devices. The cooling of the carbonate rock may comprise introducing cooling air into the shafts partially through central displacement bodies in the shafts and partially through the discharge devices. Amounts of air entering through the central displacement bodies compared to the discharge devices may vary widely from the burning shaft to the regenerative shaft.

Abstract: According to the invention, the method for burning fragmented material is carried out in at least one shaft which comprises a preheating zone, a combustion zone and a cooling zone, coal having a swelling index > 1 being supplied via combustion lances, and the temperature of the coal in the combustion lances being maintained below a temperature value at which melting phases of the coal used are formed.

Abstract: A method for burning lumpy stock is performed in at least one shaft which comprises a preheating zone, a burning zone and a cooling zone. Coal with a swelling index>1 is supplied together with a transport medium via burner lances which have burner tips. The coal together with the transport medium emerges into the shaft, wherein the temperature of the coal in the burner lances is kept below a temperature value at which melt phases of the coal that is used are formed. Here, for the transportation of the coal, use is made of a transport medium which, in the shaft, in the region directly adjacent to the burner tip, forms an oxygen-depleted atmosphere in order to delay the ignition of the coal after it emerges from the burner lance.

Abstract: The method according to the invention for operating a PFR lime kiln having at least two shafts, which each have a preheating zone, a combustion zone and a cooling zone, and an overflow channel which connects the two shafts, substantially comprises the following method steps: the two shafts are operated alternately as a combustion shaft and exhaust gas shaft, combustion air and fuel are supplied to the combustion shaft, a corresponding flame length being formed, and the hot gases which are produced in the combustion shaft reach the exhaust gas shaft via the overflow channel, at least one parameter of the hot gases which is characteristic of the formation of the flame length being established by means of direct or indirect measurement in the region of the overflow channel and the ratio of fuel to combustion air being adjusted in accordance with this parameter in order to adjust a predetermined flame length.

Abstract: According to the invention, the method for burning fragmented material is carried out in at least one shaft which comprises a preheating zone, a combustion zone and a cooling zone, coal having a swelling index>1 being supplied via combustion lances, and the temperature of the coal in the combustion lances being maintained below a temperature value at which melting phases of the coal used are formed.

Abstract: The method according to the invention for operating a PFR lime kiln having at least two shafts, which each have a preheating zone, a combustion zone and a cooling zone, and an overflow channel which connects the two shafts, substantially comprises the following method steps: the two shafts are operated alternately as a combustion shaft and exhaust gas shaft, combustion air and fuel are supplied to the combustion shaft, a corresponding flame length being formed, and the hot gases which are produced in the combustion shaft reach the exhaust gas shaft via the overflow channel, at least one parameter of the hot gases which is characteristic of the formation of the flame length being established by means of direct or indirect measurement in the region of the overflow channel and the ratio of fuel to combustion air being adjusted in accordance with this parameter in order to adjust a predetermined flame length.

Abstract: A method for burning lumps of material, in particular limestone, is carried out in a regeneration shaft kiln (3) with at least two kiln shafts (1, 2) interconnected by an overflow line (19) and in which the material to be burned passes through an upper pre-heating zone (8), a central combustion zone (18) and a lower cooling zone (14). Combustion gas with a low calorific value of less than 7.5 megajoules (MJ) per m3 is periodically and alternately supplied to each of the shafts (1, 2) through burner lances (9, 25) after being pre-heated by heat exchange with process gas of the combustion process. The combustion gas is pre-heated in a heat exchanger (21) and/or by means of a surface of the burner lances (9, 25) which extend through the pre-heating zone (8), said surface being enlarged to enhance heat exchange.

Abstract: In a method for burning carbonate-containing material the latter moves as a result of gravity in counter-current to the cooling and combustion air through a shaft kiln. The fuel supply takes place by means of burning lances introduced into the granular burning material at right angles to the shaft wall. On limiting the grain size and the residence time as a result of this type of fuel supply it is possible to achieve high burning temperatures even suitable for hard burning without there being any sintering together of the granular burning material.

Abstract: In a method for burning carbonate-containing material the latter moves as a result of gravity in counter-current to the cooling and combustion air through a shaft kiln. The fuel supply takes place by means of burning lances introduced into the granular burning material at right angles to the shaft wall. On limiting the grain size and the residence time as a result of this type of fuel supply it is possible to achieve high burning temperatures even suitable for hard burning without there being any sintering together of the granular burning material.