A furnace system includes a regenerative furnace with a melting tank and first and second regenerators. In a forward operating mode, combustion air enters and travels through the first regenerator before exiting the first regenerator into the melting tank while exhaust fluids exit the melting tank into the second regenerator and travels through the second regenerator before exiting the second regenerator. In a reverse operating mode, the flow is reversed. The system also includes a preheater for preheating materials supplied to the melting tank. Portions of the combustion air traveling through the first regenerator in the forward operating mode and the second regenerator in the reverse operating mode are diverted before entering the melting tank and mixed with fluids exhausted from the fluid outlet of the preheater for delivery to the fluid inlet of the preheater.

A stepwise gas distribution and graded oxygen supplementation device for distribution of high-ratio circulating flue gas is provided. The circulating flue gas distribution main pipe includes stepped sections communicated with each other in sequence, and pipe diameters of the stepped sections are reduced in sequence along a flue gas moving direction. The circulating flue gas distribution branch pipes are each in communication with and arranged at one side of the corresponding stepped section. The flue gas sealing cover is in communication with gas outlet ends of the circulating flue gas distribution branch pipes. The oxygen supplementing devices are arranged in the circulating flue gas distribution branch pipes needing to increase oxygen content. The oxygen supply device is in communication with gas inlet ends of the oxygen supplementing devices.

A stepwise gas distribution and graded oxygen supplementation device for distribution of high-ratio circulating flue gas is provided. The circulating flue gas distribution main pipe includes stepped sections communicated with each other in sequence, and pipe diameters of the stepped sections are reduced in sequence along a flue gas moving direction. The circulating flue gas distribution branch pipes are each in communication with and arranged at one side of the corresponding stepped section. The flue gas sealing cover is in communication with gas outlet ends of the circulating flue gas distribution branch pipes. The oxygen supplementing devices are arranged in the circulating flue gas distribution branch pipes needing to increase oxygen content. The oxygen supply device is in communication with gas inlet ends of the oxygen supplementing devices.

There is provided a kiln assembly comprising a kiln having an external heat supply and a heat treatment chamber configured to contain material to be processed, the heat treatment chamber including a hot section wherein the material flowing therein is heated by the external heat supply; a pre-heating section; a cooling section; and a heat transfer conduit circuit. The pre-heating, hot, and cooling sections are in material communication. The heat transfer conduit circuit forms a closed loop in which circulates a heat transfer fluid and has a pre-heating segment and a cooling segment respectively in heat exchange with the pre-heating and the cooling sections. The heat transfer fluid respectively releases heat to the material located in the pre-heating section and absorbs heat from the material located in the cooling section. There is also provided a method for recovering heat during operation of a kiln assembly.

Providing an implementable renewable fuel gas plant processes with management of greenhouse gases with minimal changes to existing plant set ups is a technical challenge to be addressed. Embodiments herein provide a system for renewable fuel gas generation and utilization in industrial plants with carbon dioxide as heat carrier. The system design integrates renewable fuel gas (H.sub.2) which is generated within the system and utilized to meet the thermal energy requirements of the production process. CO.sub.2 produced as byproduct of calcination in a process equipment, such as during calcination in cement plant is used as a heat-transferring medium to heat the H.sub.2. Further, the system provides recycling of the generated byproducts by separating the exhaust gases, comprised of CO.sub.2 and H.sub.2O. The H.sub.2O is recycled to generate H.sub.2 via electrolysis. The separated CO.sub.2 again serves as a heat-transferring medium, while the excess CO.sub.2 is sequestrated.

The invention provides a powder-gas heat exchanger for exchanging heat between a powder stream and a gas stream in counter-current flow comprising a powder stream mass flow rate substantially equal to a gas stream mass flow rate in a vertical shaft heat exchanger. A hot gas stream may be adapted for use in heating a cool solids stream, or a cool gas stream may be adapted for use in cooling a hot solids stream.

The invention provides a powder-gas heat exchanger for exchanging heat between a powder stream and a gas stream in counter-current flow comprising a powder stream mass flow rate substantially equal to a gas stream mass flow rate in a vertical shaft heat exchanger. A hot gas stream may be adapted for use in heating a cool solids stream, or a cool gas stream may be adapted for use in cooling a hot solids stream.

A system and method generate electricity from radiant heat emitted by a heated Ladle in metal recycling operation. The Ladle, either preheated empty (System-1) or containing liquid metal (System-2), radiates heat at between 200 C. and 2000 C. System-1 and System-1 are identified as Waste-Heat-Sources. Radiant heat from Waste-Heat-Sources is captured by a proximate Heat-to-Electricity Generator (HTE-Generator). The HTE-Generator converts radiant heat into electrical energy, powering the recycling process and reducing factory thermal load to lower air-conditioning energy costs. Configurations include fixed, overhead hoist-mounted, scissor-lift-mounted, or overhead and surrounding setups.

Waste heat recovery in an ammonia-based desulfurization and decarbonization system. The heat in the decarbonization system may be removed by using the heat of the process gas before desulfurization. The process gas before desulfurization may heat an intermediate medium through a gas heat exchanger. The intermediate medium may drive a refrigerator for refrigeration. A refrigerant may obtain the cooling capacity and may then cool the decarbonized process gas through a liquid-liquid heat exchanger.

Waste heat recovery in an ammonia-based desulfurization and decarbonization system. The heat in the decarbonization system may be removed by using the heat of the process gas before desulfurization. The process gas before desulfurization may heat an intermediate medium through a gas heat exchanger. The intermediate medium may drive a refrigerator for refrigeration. A refrigerant may obtain the cooling capacity and may then cool the decarbonized process gas through a liquid-liquid heat exchanger.