A device for producing expanded granulated material from grains of sand with an expanding agent includes a furnace with a furnace shaft, which has upper and lower ends. A conveying section extends between the ends and passes through separately-arranged heating zones in a conveying direction. At least one feeder charges at least the unexpanded material into the furnace shaft at one end toward the other end. At least one rotatable shaft insert is arranged at least in sections in the furnace shaft and has at least one scraper blade forming with an inner wall of the furnace shaft at least one gap having a gap width and being designed, during rotation of the at least one shaft insert in an operating state of the device, to remove caking on the inner wall at least in sections if a thickness of the caking is greater than the respective gap width.

A device for producing expanded granulated material from grains of sand with an expanding agent includes a furnace with a furnace shaft, which has upper and lower ends. A conveying section extends between the ends and passes through separately-arranged heating zones in a conveying direction. At least one feeder charges at least the unexpanded material into the furnace shaft at one end toward the other end. At least one rotatable shaft insert is arranged at least in sections in the furnace shaft and has at least one scraper blade forming with an inner wall of the furnace shaft at least one gap having a gap width and being designed, during rotation of the at least one shaft insert in an operating state of the device, to remove caking on the inner wall at least in sections if a thickness of the caking is greater than the respective gap width.

A method and apparatus for protecting a furnace floor of a black liquor recovery boiler, where the furnace floor is covered by a protective layer, the protective layer being formed of a salt mixture including at least two different salts.

The invention relates to a slide valve (20) having a slide valve plate (32) movable in a slide valve rail (29) between a locked position and an open position in a slide valve casing (26), said slide valve rail (29) being provided with a slide valve seal for attaining a gas-proof locked position, said slide valve rail (29) being connected to the slide valve casing (26) via a flange connection in such a manner that the slide valve rail (29) is removable from the slide valve casing (26) radially to a flow axis of the slide valve (20).

The invention relates to a slide valve (20) having a slide valve plate (32) movable in a slide valve rail (29) between a locked position and an open position in a slide valve casing (26), said slide valve rail (29) being provided with a slide valve seal for attaining a gas-proof locked position, said slide valve rail (29) being connected to the slide valve casing (26) via a flange connection in such a manner that the slide valve rail (29) is removable from the slide valve casing (26) radially to a flow axis of the slide valve (20).

A furnace having a convection section with convection tubes in a convection compartment is disclosed. The convection tubes receive and preheat hydrocarbon feed primarily by convection of heat from hot flue gas that flows into in the convection section. The convection section additionally includes a perforated distributor plate that prevents flow channeling of the hot flue gas as it flows into the convection section. The furnace also includes a radiant section having radiant tubes in a radiant compartment. The radiant tubes are in fluid communication with the convection tubes so that preheated hydrocarbon feed flows from the convection section to the radiant section. The radiant section burns fuel and heats the preheated hydrocarbon feed primarily by radiation and from the hot flue gas, which flows from the radiant section into the convection section.

A method of operating an ironmaking or steelmaking plant with low CO.sub.2-emissions is provided. Hydrogen and oxygen are generated by water decomposition and at least part of the generated hydrogen is injected as a reducing gas into one or more ironmaking furnaces with off-gas decarbonation and reinjection into the furnaces of at least a significant part of the decarbonated off-gas and at least part of the generated oxygen is injected as an oxidizing gas in the one or more ironmaking.

A method of operating an ironmaking or steelmaking plant with low CO.sub.2-emissions is provided. Hydrogen and oxygen are generated by water decomposition and at least part of the generated hydrogen is injected as a reducing gas into one or more ironmaking furnaces with off-gas decarbonation and reinjection into the furnaces of at least a significant part of the decarbonated off-gas and at least part of the generated oxygen is injected as an oxidizing gas in the one or more ironmaking.

The controller receives information including a plurality of evaluation indexes, a weight of each evaluation index, the number of times for calculating a value of an evaluation function, and initial parameter values, and performs a simulation based on the received information. Then, the controller calculates a value of an evaluation function based on a result of the simulation, and determines whether the calculated value of the evaluation function is minimum, to update parameters when it is determined that the value of the evaluation function is minimum. In the calculation of a value of the evaluation function, a value of the evaluation function is calculated again based on the number of times for calculating a value of an evaluation function. The controller generates new parameters by a genetic algorithm when a value of an evaluation function is calculated again.

The controller receives information including a plurality of evaluation indexes, a weight of each evaluation index, the number of times for calculating a value of an evaluation function, and initial parameter values, and performs a simulation based on the received information. Then, the controller calculates a value of an evaluation function based on a result of the simulation, and determines whether the calculated value of the evaluation function is minimum, to update parameters when it is determined that the value of the evaluation function is minimum. In the calculation of a value of the evaluation function, a value of the evaluation function is calculated again based on the number of times for calculating a value of an evaluation function. The controller generates new parameters by a genetic algorithm when a value of an evaluation function is calculated again.