Apparatus for supplying blast to a blast furnace (1) having a plurality of hot blast stoves (4, 5, 6), each stove including a cold blast inlet, a fuel inlet, an air supply inlet, a hot blast outlet, and a waste gas outlet; a waste heat recovery unit (30) connected to a fuel supply, the stove fuel inlet and the cold blast inlet. The stove waste gas outlets are connected to the cold blast inlets, whereby stove waste gas from one stove (5) is supplied, via the waste heat recovery unit, as cold blast to another stove (4).

Electric stove for heating a reducing gas, the electric stove including: a hollow metal shell body extending along a longitudinal direction; a refractory lining arranged on an inner surface portion of the shell body; a plurality of bricks arranged in adjacent layers extending along the longitudinal direction, where each brick includes a plurality of cavities extending straight along the longitudinal direction through the respective layer, where the cavities of adjacent layers are aligned to one another, whereby a plurality of channels for conducting the reducing gas is formed; and a plurality of heating wires for heating the reducing gas, wherein each heating wire has a diameter smaller than a diameter of a channel, and where each heating wire extends at least partially through at least one corresponding channel of the plurality of channels, such that when the electric stove is operated, a predefined heat amount is dissipated by each heating wire to a reducing gas flowing around the heating wire.

An oxy-fuel boost burner for a regenerative furnace having a pair of regenerator ports configured to alternately fire into and exhaust from the furnace, including at least one burner element corresponding to each of the regenerator ports by being positioned to fire into a complimentary region of the furnace, each burner element including a selective distribution nozzle configured to flow a first reactant and a proportional distribution nozzle configured to flow a second reactant, and a controller programmed to identify which regenerator port is currently firing and which is currently exhausting and to independently control the first reactant flow to each selective distribution nozzle such that the at least one burner element corresponding to the currently firing regenerator port has a greater than average first reactant flow and the at least one burner element corresponding to the currently exhausting regenerator port as a less than average first reactant flow.

An oxy-fuel boost burner for a regenerative furnace having a pair of regenerator ports configured to alternately fire into and exhaust from the furnace, including at least one burner element corresponding to each of the regenerator ports by being positioned to fire into a complimentary region of the furnace, each burner element including a selective distribution nozzle configured to flow a first reactant and a proportional distribution nozzle configured to flow a second reactant, and a controller programmed to identify which regenerator port is currently firing and which is currently exhausting and to independently control the first reactant flow to each selective distribution nozzle such that the at least one burner element corresponding to the currently firing regenerator port has a greater than average first reactant flow and the at least one burner element corresponding to the currently exhausting regenerator port as a less than average first reactant flow.

A thermally efficiency regenerative air preheater 250 extracts more thermal energy from the flue gas exiting a solid fuel fired furnace 26 by employing an alkaline injection system 276. This mitigates acid fouling by selectively injecting different sized alkaline particles 275 into the air preheater 250. Small particles provide nucleation sites for condensation and neutralization of acid vapors. Large particles are injected to contact and selectively adhere to the heat exchange elements 542 and neutralize liquid acid that condenses there. When the deposit accumulation exceeds a threshold, the apparatus generates and utilizes a higher relative percentage of large particles. Similarly, a larger relative percentage of small particles are used in other cases. Mitigation of the fouling conditions permits the redesign of the air preheater 250 to achieve the transfer of more heat from the flue resulting in a lower flue gas outlet temperature without excessive fouling.

A thermally efficiency regenerative air preheater 250 extracts more thermal energy from the flue gas exiting a solid fuel fired furnace 26 by employing an alkaline injection system 276. This mitigates acid fouling by selectively injecting different sized alkaline particles 275 into the air preheater 250. Small particles provide nucleation sites for condensation and neutralization of acid vapors. Large particles are injected to contact and selectively adhere to the heat exchange elements 542 and neutralize liquid acid that condenses there. When the deposit accumulation exceeds a threshold, the apparatus generates and utilizes a higher relative percentage of large particles. Similarly, a larger relative percentage of small particles are used in other cases. Mitigation of the fouling conditions permits the redesign of the air preheater 250 to achieve the transfer of more heat from the flue resulting in a lower flue gas outlet temperature without excessive fouling.

Method of operating a blast furnace installation comprising a top gas recycle blast furnace and hot stones, whereby a hydrocarbon containing fuel is transformed into a transformed gas stream consisting mainly of CO and H.sub.2 and substantially devoid of hydrocarbon, whereby a low-heating-value gaseous fuel is generated comprising a mixture of said transformed gas with a portion of the CO.sub.2-rich tail gas obtained by decarbonatation of the blast furnace gas, and whereby said low-heating-value fuel is used to heat the hot furnace gas is heated before being injected into the blast-furnace.

Method of operating a blast furnace installation comprising a top gas recycle blast furnace and hot stones, whereby a hydrocarbon containing fuel is transformed into a transformed gas stream consisting mainly of CO and H.sub.2 and substantially devoid of hydrocarbon, whereby a low-heating-value gaseous fuel is generated comprising a mixture of said transformed gas with a portion of the CO.sub.2-rich tail gas obtained by decarbonatation of the blast furnace gas, and whereby said low-heating-value fuel is used to heat the hot furnace gas is heated before being injected into the blast-furnace.