An example oven for heating fibers includes a chamber having upper and lower portions and a supply structure between first and second ends of the chamber, wherein the supply structure is in communication with a first heating system and is configured to direct first heated gas from the first heating system into the upper portion of the chamber to heat fibers in the upper portion at a first temperature, and wherein the supply structure is in communication with a second heating system and is configured to direct second heated gas from the second heating system into the lower portion of the chamber to heat fibers in the lower portion at a second temperature different than the first temperature such that the upper and lower portions of the chamber maintain the different temperatures without a physical barrier between the upper and lower portion.

An arrangement for burning lime mud into lime in a lime kiln. The lime mud flows counter-currently to flue gases from a feed end to a firing end and the fuel used is flue gas that is produced by gasifying a fuel in the presence of combustion air in a gasifier. The combustion air for gasification is preheated with heat generated in lime mud combustion. The arrangement is provided with a conduit between the lime kiln and the gasifier for leading air from the lime kiln into the gasifier as combustion air. At least a portion of the combustion air for gasification is preheated with heat generated in the lime mud combustion so that air is led into cooling of lime obtained in the combustion and further into the kiln, from or through the firing end of which air is taken into the gasification.

A method for calcination includes providing a heated coarse solid particle stream with a carbon dioxide rich sorbent to a reactor having a rotatable container.

The invention provides a vertical annealing furnace including a heating zone and a soaking zone without any partition wall therebetween. The furnace has furnace-to-refiner gas suction openings disposed in a lower portion of a joint between the soaking zone and a cooling zone and in the heating zone and/or the soaking zone except a region extending 6 m in a vertical direction and 3 m in a furnace length direction both from a steel strip inlet at a lower portion of the heating zone. The furnace has refiner-to-furnace gas ejection openings disposed in a region in the joint between the soaking zone and the cooling zone, the region being located above the pass line in the joint, and in a region in the heating zone located above 2 m below the center of upper hearth rolls in the vertical direction.

A heat-recovering oven system based on temperature gradient comprises: multiple chambers arranged in a sequence, the chambers configured for operating at various temperatures according to a temperature gradient arrangement that spans the sequence; a conveyor configured for transporting product through the multiple chambers in the sequence for heat treatment according to the temperature gradient arrangement; and multiple temperature-segregated heat exchanger systems, each heat exchanger system including a heat exchanger, a conduit to at least one of the chambers based on its temperature in the temperature gradient arrangement, and a return conduit from the at least one chamber to the heat exchanger.

A continuous heating furnace includes one or a plurality of closed type gas heaters each having a combustion chamber, a guide section that guides an exhaust gas, an exhaust hole that discharges the exhaust gas and a first radiation surface that extends in a direction perpendicular to a baking object conveyance direction wherein the first radiation surface is heated by combustion in the combustion chamber and heat from the guide section and transfers radiant heat to the baking object. The continuous heating furnace also has at least one exhaust heat transfer unit that is juxtaposed with a corresponding closed type gas heater in the conveyance direction, wherein the at least one exhaust heat transfer unit has a second radiation surface that communicates with the exhaust hole of a closed type gas heater and is heated by the exhaust gas, and a heat transfer acceleration unit that accelerates heat transfer from the exhaust gas to the second radiation surface in a direction perpendicular to the conveyance direction of the second radiation surface.

A process for heating a metal feedstock (31) fed in continuous to a smelting furnace (30) through a second horizontal heating section (34) through which hot discharge fumes collected from said furnace (30) pass, said fumes exerting a heating phase of said feedstock (31), characterized in that, immediately before entering said second heating section (34), the feedstock (31) is subjected to a preheating phase by heating means other than the discharge fumes collected from the smelting furnace (30). In a plant for the embodiment of said process, said different heating means are envisaged inside a first preheating section (33), which is operatively connected with said second heating section (34) by means of an intermediate fume evacuation section (35), the fumes coming from said sections (33) and (34) being conveyed to said section. Said sections (33, 34) preferably have a tunnel configuration.

The present invention relates to a denitration and waste heat recovery integrated furnace, comprising a denitration system, a desulfurization system and a waste heat recovery system. An air outlet of the denitration system is connected to an inlet of a dust collector (4), an outlet of the dust collector (4) is connected to an air inlet of the desulfurization system, an air outlet of the desulfurization system is connected to an air compressor (6) of the waste heat recovery system, and the waste heat recovered by the air compressor (6) is used for heat energy utilization of other departments.

A method for treating exhaust gas in an exhaust gas treatment device of a system may involve withdrawing exhaust gas from a processing device for mechanically and/or thermally processing an inorganic material of the system. The material to be fed to the processing device may be preheated by heat exchange with the exhaust gas. Further, a temperature of the exhaust gas entering the exhaust gas treatment device may be adjusted by adapting the exchange of heat between the exhaust gas and the inorganic material. In some examples, the exhaust gas treatment device may comprise an oxidation catalytic converter and/or a reduction catalytic converter.

Apparatus. methods. and systems for heat treatment of solid materials utilizing an indirect rotary calciner comprising one or more thermal expansion tolerant inner tubes fixed to an outer rotating shell. for example. by one or more resilient support members. The described methods of thermal treatment may be particularly utilized with cement and lime production processes and/or other heat treatment applications. such as pyrolysis.