Abstract: A method and apparatus for removing purifying vaporizable contaminants such as mercury from a particulate material. Particulate material is first contacted with heated gases to vaporize the contaminants and entrain the material in the gases. The gases are directed to a first dust collector to remove the entrained particulates, after which a sorbent or chemical reagent is injected in the gases to interact with the contaminants and form a contaminant containing product that is entrained in the gases. The product is then separated from the gases in a second collector.
February 5, 2008
Date of Patent:
September 14, 2010
F L Smidth A/S
Ove Lars Jepsen, Peter T. Paone, III, John S. Salmento
Abstract: Described is a method for manufacturing cement clinker by which method cement raw meal is preheated and burned in a plant comprising a cyclone preheater (1) and a kiln (5). The method is peculiar in that that at least a portion of the raw meal is extracted from the cyclone preheater (1), that this raw meal is introduced into a separate unit (21) in which it is given a retention time under oxidating conditions provided by means of a gas stream for forming SO2 and for expelling organic carbon, that the formed SO2 and the expelled organic carbon are subsequently discharged from the separate unit (21) entrained in the gas stream for further treatment in a subsequent process stage, and that the raw meal is reintroduced into the cyclone preheater (1). Hereby is obtained an effective reduction of the VOC, CO as well as the SO2 emission without necessitating utilization of additional energy for heating.
Abstract: Described is a method as well as a plant for preheating particulate or pulverulent material such as cement raw meal or similar material in a cyclone preheater (1), comprising at least two cyclone stages, each comprising a riser duct (2a, 2b, 2c, 2d) and a cyclone (1a, 1b, 1c, 1d). The method is peculiar in that a portion of the material which is fed to at least one cyclone stage is introduced to the first part of the riser duct, viewed in the direction of travel of the exhaust gases, and is heated from a temperature of maximum 450° C. to a temperature of at least 550° C., and in that the remaining material which is fed to the same cyclone stage is introduced into the last part of the said riser duct. As a result, there will be a reduction in the amount of SO2 which is discharged from the cement plant preheater as emission, without a simultaneous increase in energy consumption.
Abstract: The invention Described is a device (1) for dividing a stream of particulate or pulverulent material into at least two substreams. The device has a housing (2) with a substantially vertical inlet duct (3) and two or more outlet ducts (4, 5, 6, 7) emanating from separate openings, and being separated by partition walls (9) extending radially relative to the centreline of the inlet duct (3). The device also has a rotor 11) which is located in immediate extension of the inlet duct (3), with its axis of rotation coinciding with the centreline (10) of the inlet duct. The rotor (11) has a radially configured surface (11a) for directing the falling material stream radially outwards into the free space (12) above the outlet ducts. The device is peculiar in that the radial partition walls (9) can be adjusted in the circumferential direction. The result will be a freely variable ratio between an arbitrary number of outlet substreams.
Abstract: A method and plant for manufacturing cement clinker are disclosed, in which cement raw meal is calcined in a calciner. The calciner comprises an upper zone and a lower zone, where fuel, combustion gas and raw meal are introduced into the upper zone of the calciner and directed downward through the calciner. The combustion gas and raw meal are introduced tangentially into the calciner and subject to rotation follow a spiral-shaped flow path, and, under the action of gravity, the raw meal is primarily directed down along the wall of the calciner. The rotation of the combustion gas in at least the lower zone of the calciner is subjected to braking and approximately simultaneously or subsequently at least some of the combustion gas and at least some of the raw meal in the lower zone of the calciner is directed in the direction towards the center-line of the calciner.
Abstract: Described is a plant for manufacturing cement clinker comprising a preheater (1) which comprises at least one last cyclone (1d) and at least one next-to-last cyclone (1c) which is connected in series via a gas duct (2c) to and fed with a gas from the last cyclone (1d), a calciner (3) which comprises at least one inlet opening (9) for introducing preheated raw meal from the last cyclone (1d), and which is connected to a subsequent separating cyclone (4), a gas duct (2d) which connects the separating cyclone (4) to the last cyclone (1d), and which comprises at least one inlet opening (11) for introducing preheated raw meal from the next-to-last cyclone (1c).
Abstract: A description is given of a method as well as a plant for manufacturing cement clinker by which method cement raw meal is preheated in a preheater (1), calcined in a calciner (3) comprising an upper end (3a) and a lower end (3b), burned into clinker in a kiln (5) and cooled in a subsequent clinker cooler (7).