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 method of ironmaking using full-oxygen hydrogen-rich gas which includes hot transferring and hot charging the high-temperature coke, sinter and pellet into the ironmaking furnace through transferring and charging device, and injecting oxygen and hydrogen-rich combustible gas at a predetermined temperature into the ironmaking furnace through the oxygen tuyere and the gas tuyere disposed at the ironmaking furnace, respectively. It also provides an apparatus for ironmaking using full-oxygen hydrogen-rich gas which includes a raw material system, a furnace roof gas system, a coke oven gas injecting system, a dust injecting system, a slag dry-granulation and residual heat recovering system and an oxygen system. Additionally an apparatus and method for hot transferring and hot charging of ironmaking raw material is disclosed.

Provided is a system for recovering waste heat discharged from distillation columns, incinerators, blast columns, smelting columns, and the like at relatively low temperatures to produce hot water in high efficiency, which can be used in various industrial fields. The investment and operating costs of the waste heat recovery system are relatively low as compared with the conventional systems.

A process and plant for preheating a metal charge fed in continuous to an electric melting furnace through a preheating tunnel provided with side walls, a vault and a horizontal conveyor, wherein the metal charge is enveloped in countercurrent by fumes or exhaust gases exiting from the electric melting furnace, includes causing an air intake from the surrounding environment through openings along the preheating tunnel to complete the combustion of the fumes or exhaust gases. The intake is regulated by acting on suction fans and/or on the openings, based on measurements by temperature sensors and/or the composition of the outgoing gases in or downstream of the terminal part of the tunnel. The metal charge is enveloped by jets of gas ejected through a plurality of nozzles arranged non-uniformly longitudinally on the vault of the tunnel, with a greater concentration on the top of the vault of the tunnel.

A cooling assembly for cooling exhaust gases emitted from a steel-making furnace includes a body having a cross-sectional shape with a thickness defined between an outer surface and an inner surface thereof. The body includes a first mounting end having a first length and a second mounting end having a second length, the second length being different from the first length. The body is arcuately-shaped with a concave inner surface and convex outer surface, and the second mounting end is spaced from the first mounting end. A fluid conduit is defined between the inner surface and the surface for a cooling fluid to flow therethrough.