A blast furnace operation method comprising a blast furnace to start up smoothly and perform operation after suspending air blowing by removing as much as possible residual coke that remains inside the furnace during suspension of air blowing and becomes an obstacle to discharging solidified matter. In this blast furnace operation method, air blowing is suspended with the height of a surface of a raw material-filled layer immediately above a blast-furnace tuyere reduced below the height of an upper end of a blast-furnace bosh and then air blowing is resumed. After air blowing into the blast furnace is suspended, oxygen or oxygen and a combustible gas are blown in through a burner inserted into a taphole to combust coke remaining inside the furnace and reduce the volume of residues inside the furnace, and after new coke is charged to a region where the volume decreased, air is blown through a tuyere.

A blast furnace operation method comprising a blast furnace to start up smoothly and perform operation after suspending air blowing by removing as much as possible residual coke that remains inside the furnace during suspension of air blowing and becomes an obstacle to discharging solidified matter. In this blast furnace operation method, air blowing is suspended with the height of a surface of a raw material-filled layer immediately above a blast-furnace tuyere reduced below the height of an upper end of a blast-furnace bosh and then air blowing is resumed. After air blowing into the blast furnace is suspended, oxygen or oxygen and a combustible gas are blown in through a burner inserted into a taphole to combust coke remaining inside the furnace and reduce the volume of residues inside the furnace, and after new coke is charged to a region where the volume decreased, air is blown through a tuyere.

A plastic conversion feeding system serves to transport a feedstock through different processing units or stations to a vessel wherein chemical and/or physical reactions occur to produce suitable, useful end products. Various processing units include a homogenizer for breaking up said feedstock, a size reduction device for reducing the feedstock to particles and densifying the same, a heating and/or blending device for heating said feedstock, and a feed conduit connecting said heating and blending device to said vessel. The feedstock conversion unit vessel through various cracking, reforming, condensation, recombination, and recracking operations, produces a mixture of useful gases and condensable gases.

A plastic conversion feeding system serves to transport a feedstock through different processing units or stations to a vessel wherein chemical and/or physical reactions occur to produce suitable, useful end products. Various processing units include a homogenizer for breaking up said feedstock, a size reduction device for reducing the feedstock to particles and densifying the same, a heating and/or blending device for heating said feedstock, and a feed conduit connecting said heating and blending device to said vessel. The feedstock conversion unit vessel through various cracking, reforming, condensation, recombination, and recracking operations, produces a mixture of useful gases and condensable gases.

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.

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.

Numerous examples of a vertical kiln for manufacturing cement are disclosed. In one example, a vertical kiln comprises a housing comprising a top opening to receive unprocessed material and a bottom opening to output processed material; a combustion system to heat the unprocessed material within the housing to generate the processed material; a thermocouple located within the housing to measure temperature; and a control system to control the combustion system in response to temperature data from the thermocouple.

Numerous examples of a vertical kiln for manufacturing cement are disclosed. In one example, a vertical kiln comprises a housing comprising a top opening to receive unprocessed material and a bottom opening to output processed material; a combustion system to heat the unprocessed material within the housing to generate the processed material; a thermocouple located within the housing to measure temperature; and a control system to control the combustion system in response to temperature data from the thermocouple.

The present invention concerns an apparatus and a method for manufacturing a product from a raw material. The apparatus comprises a rotary kiln having a first rotary kiln end and a second rotary kiln end, and a cooling unit which is connected to the second rotary kiln end, wherein a process direction is provided leading through the rotary kiln from the first rotary kiln end to the second rotary kiln end and further through the cooling unit, wherein the cooling unit is configured to transport the product in the process direction through the cooling unit for cooling the product, the rotary kiln comprising a burning unit at the second rotary kiln end, the burning unit being configured to receive a flammable material and an ignition gas to create heat inside the rotary kiln and to produce a combustion gas containing carbon dioxide, the rotary kiln being configured to transport raw material received at the first rotary kiln end in the process direction towards the second rotary kiln end, and, by using the heat, to transform the raw material into the product and into a resigning gas comprising carbon dioxide, characterized in that the apparatus comprises a gas outlet configured to remove an exhaust gas comprising the resigning gas and the combustion gas from the rotary kiln, and that the cooling unit is configured to transport a cooling gas in the process direction over the product.

The present invention concerns an apparatus and a method for manufacturing a product from a raw material. The apparatus comprises a rotary kiln having a first rotary kiln end and a second rotary kiln end, and a cooling unit which is connected to the second rotary kiln end, wherein a process direction is provided leading through the rotary kiln from the first rotary kiln end to the second rotary kiln end and further through the cooling unit, wherein the cooling unit is configured to transport the product in the process direction through the cooling unit for cooling the product, the rotary kiln comprising a burning unit at the second rotary kiln end, the burning unit being configured to receive a flammable material and an ignition gas to create heat inside the rotary kiln and to produce a combustion gas containing carbon dioxide, the rotary kiln being configured to transport raw material received at the first rotary kiln end in the process direction towards the second rotary kiln end, and, by using the heat, to transform the raw material into the product and into a resigning gas comprising carbon dioxide, characterized in that the apparatus comprises a gas outlet configured to remove an exhaust gas comprising the resigning gas and the combustion gas from the rotary kiln, and that the cooling unit is configured to transport a cooling gas in the process direction over the product.