Abstract:
A cement production plant may include a preheater for preheating raw meal, a calciner for calcining the preheated raw meal, and a furnace with a furnace burner for firing the raw meal to form cement clinker. The furnace has a combustion gas inlet for admitting a combustion gas with an oxygen content of 30% to 75% into the furnace. The cement production plant may also include a cooler for cooling the cement clinker. The calciner and the furnace each have at least one respective fuel inlet for admitting at least one fuel into the calciner and the furnace. The calciner and the furnace each have at least one respective inert gas inlet for respectively admitting inert gas into the calciner and the furnace.
Abstract:
A rotating air distributor for rotary reactors such as rotary kilns for the gasification of biomass and other carbonaceous materials for efficient mixing and maximum conversion of solid biomass and other carbonaceous materials into synthesis fuel gas is disclosed. The invention includes a gas distribution port comprises of one main supply from which several discharge nozzles emerge at different angles and at different locations along the length of the reactor to provide distribution of gas throughout the intended length of the reactor. The discharge of gas from the gas distribution port is adjusted by the variable position of a plug inside the port that can be adjusted during the operation of the kiln to achieve optimum gas-solid interaction along the length of the reactor. The rotating action of the gas distribution port also facilitates and eases the passage of reacted biomass solid and other carbonaceous material residue through the reactor.
Abstract:
A kiln comprising a substantially cylindrical drum (11) supported from a support structure for rotation about its central axis whereby the drum is supported such that the central axis is generally horizontal and whereby the drum is configured and/or arranged such that rotation of the drum will cause fluid particulate material to flow from one end (13) to other end (15). The one end being associated with a fuel inlet (33) and the other end being provided with a discharge (37) for combustion products and heat. The inner face of the side wall of the drum is provided with a plurality of ports (29) which are located at spaced intervals along and around the interior of the drum and which open into the interior of the drum, the one end being closed by an end assembly (23) fixed relative to the support structure whereby the one end is in close abutting relationship with the end assembly. An opening (25) is provided in the end assembly, the opening connected to a source of air (31). A set of passageways (27) are provided at angularly displaced positions around the kiln, said passageways communicating with the ports, the inlets of passageways opening into the face defining the one end, the opening being positioned such that on rotation of the drum the inlets of the passageways rotate past the opening.
Abstract:
The present invention provides a method capable of producing good hot-briquette iron using high-temperature reduced iron discharged at a high temperature from a reducing furnace such as a rotary hearth furnace. The method includes a temperature control step of cooling the high-temperature reduced iron and controlling the temperature of the reduced iron to an appropriate hot-forming temperature of over 600° C. and 750° C. or less, and a step of producing hot briquette iron by hot-forming the high-temperature reduced iron of the appropriate hot-forming temperature with a briquetting machine. The temperature control step includes substantially horizontally holding a rotating drum having a feed blade spirally provided on the inner periphery thereof, charging the high-temperature reduced iron in the rotating drum and passing it through the rotating drum by rotating the rotating drum while maintaining the inside of the rotating drum in a non-oxidizing atmosphere with inert gas, and cooling the outer peripheral surface of the rotating drum by contact with a cooling fluid during the passage of the high-temperature reduced iron through the rotating drum to indirectly cool the reduced iron so that the temperature of the reduced iron is the appropriate hot-forming temperature.
Abstract:
A method for feeding lime mud into a lime kiln including a rotary kiln shell having an interior between a first end wall and a second end wall, the method including: feeding the lime mud into a flue gas flow in the interior of the rotary kiln shell or in close proximity to the shell to pretreat the lime mud; separating the pretreated lime mud from the flue gas flow; conveying the separated lime mud into the lime kiln, and calcining the separated lime mud in the lime kiln.
Abstract:
An exhaust gas treatment method including: (A) a step of treating exhaust gas from cement manufacturing equipment by using a dust collector 9 to collect dust containing chlorinated organic compounds, and discharging the exhaust gas after the treatment by the dust collector 9, and (B) a step of charging all or part of the dust collected by the dust collector 9 into a place (e.g. a rotary kiln 5, a pre-calciner 6, and a cyclone 4d) having a temperature of at least 800null C. inside the cement manufacturing equipment. The remainder of the dust from step (B) maybe charged into a place (e.g. a raw material supply passage 3) having a temperature below 800null C. inside the cement manufacturing equipment, provided the amount of the remainder to be charged is smaller than a certain amount. Chlorinated organic compounds such as dioxins in the exhaust gas can be decomposed efficiently to be made harmless, merely by including simple and low-cost means (e.g. a dust feeding means 12, etc.).
Abstract:
The invention in its various embodiments includes an apparatus and a method for improving combustion in a cement kiln system. The apparatus in one embodiment includes a precalciner and an oxygen source coupled to the precalciner. The method in one embodiment includes introducing oxygen into the precalciner of a cement kiln system.
Abstract:
A kiln is provided with oxidant injection locations upstream of air blowers which blow air into the kiln. The addition of oxygen into the kiln increases the cooling capacity of a clinker cooler, and enhances combustion in the kiln.
Abstract:
Processes and plants for producing cement clinker, in which an oxygen-containing gas having a proportion of 15% by volume or less of nitrogen and a proportion of 50% by volume or more of oxygen is conveyed from a first section of the cooler directly adjoining the top of the furnace into the rotary furnace and is optionally additionally conveyed to the calciner, and where the total gas streams fed in to the combustion processes consist to an extent of more than 50% by volume (preferably more than 85% by volume) of oxygen.