Abstract: In a kiln plant for burning mineral raw materials, e.g. cement raw materials, by means of nitrogen containing, solid fuel, e.g. coal, and which plant comprises a kiln (1), a material cooler (2) coupled after the kiln and a multistring, multistage preheater (18-27 and 18'-27') mounted before the kiln, the one string, the kiln string (18-27), being in direct connection with the kiln riser pipe (8) and the second string, the calcining string (18'-27'), being connected to a separate calcinator (4) to which combustion air is supplied in the form of spent cooler air through an inlet (7), an NO.sub.x -reducing zone is established in the kiln riser pipe (8) and a part of the kiln string from an inlet (13) for nitrogen containing solid fuel of a fuel duct (10) and an inlet (12) of a branch-off (14) for the supply of spent cooler air. The length of the NO.sub.

Abstract: A cement clinker-producing plant has a suspension preheater (1,2,3), a calciner (4) united with a stationary reactor (6) and coolers (7,8). Air is blown up through the cooler (7) into the reactor (6) where a spouted bed, in which the clinker is burnt, is produced. The air flow is controlled so that only clinker particles which have grown to a certain size can fall through the air flow into the cooler (7).

Abstract: A method and apparatus of cofiring hazardous organic waste in solid, pasty, greasy or sludge form by introducing it directly into the burning zone of an industrial rotary kiln and burning the waste in the burning zone simultaneously with cement, lime or lightweight aggregate. Specifically disclosed are five exemplary embodiments for introducing the waste directly into the burning zone of the kiln, i.e., (1) through a side opening in the kiln, (2) ballistically, (3) by pre-mixing with a powder or granular material and pneumatically injecting the non-sticky mixture, (4) by shredding steel drums containing the waste and thereafter separating the drum fragments and mixing the remaining waste with powder or granular material (i.e. as in (3) and (5) by pregasification of the waste.

Abstract: In an electrostatic precipitator for cleansing flue gases from industrial plants, comprising one or more precipitator sections powered from a separate continuous or intermittent DC-voltage electric supplies, a method and apparatus for detecting back corona, i.e. discharges in the dust layer precipitated on the collecting electrodes of an emission electrode system during the cleansing process, by making periodic upward adjustment of the precipitator current for each DC-voltage supply until spark-over occurs, and where after spark-over or a blocking of the precipitator current for a predetermined period of time if no spark-over occurs, the minimum value of the precipitator voltage is compared wtih the minimum value before the spark-over or before the blocking period, the latter minimum value being corrected by means of a predetermined sensitivity factor.

Abstract: To facilitate a smooth and quick start-up of a rotary kiln, a Fuzzy Logic Control system is proposed, the principal feature of which is to mandate control actions to decrease the specific heat consumption along a straight line from an initial high value to a steady-state value established for the kiln, and then to switch over to an existing steady-state fuzzy logic control mode. In the start-up phase, further process variables are preferably measured and monitored against reference values to mandate concurrent control actions influencing the Fuzzy Logic Control system in a weighted manner.

Abstract: A method of granulating lime powder or the like, use being made of a counterflow mixing machine with scraping and mixing means. The mixing means are rotated about a substantially vertical axis, and the bottom of the mixing vessel is covered with a layer of substantially ball shaped bodies, and raw material, e.g. lime, is subsequently added in a suitable amount having a specified moisture content, the mixing means subsequently being rotated such that the raw material after a specified period of time dependent on its moisture content, sticks to the ball shaped bodies.

Abstract: A vertical roller mill has a rotatable grinding table (1) which is fed with material to be ground through a feed pipe (14) so that a cone of material is formed between the bottom of the pipe and the table, and scrapers (25) for intercepting the cone and spreading the material over the table and under grinding rollers. In order to avoid the feed pipe running empty so that the cone is not formed, sensors (21) sense the level of material in the pipe and controlling means (19,20) responsive to the sensors adjust the height of the feed pipe and/or the angle of the scrapers.

Abstract: A cyclone for treating pulverous raw material suspended in a hot gas stream, for use, for example, in a suspension preheater plant for treating cement raw materials and similar materials, comprises a tubular chamber with a vertical axis, a cone shaped bottom with a central outlet for precipitated material, a central outlet for hot gases at the top of the chamber and a tangential inlet for hot air. The inlet has a chamfered wall causing the suspension stream entering the cyclone through the duct leading to the inlet to be deflected outwards against the inner surface of the chamber wall and downwards into the cyclone chamber.

Abstract: A tubular reactor for heat treatment of granular material in suspension has a vessel (1) up through which a flow of gas and burning fuel passes. The vessel contains vanes (20) which cause the gas to follow a helical path and fling outwards entrained material, which falls down the vessel wall and is displaced inwardly by frusto-conical rings (30).

Abstract: Equipment for monitoring the concentration of components in a gas flow has two probes (1,2) located at (63) in the gas flow. Sample gas is drawn through the probes and through pipes (3,4) by a pump (8), and test samples are extracted from the pipes by pumps (11,12) and fed to an analysis line (10). The probes (1,2) work alternately, and, when one is not working, it may be cleaned by blowing air through from a source (9), while the corresponding one of the pipes (3,4) is blocked from the line (10) by valves (13-16).

Abstract: A probe for taking a sample of dusty gas has a duct (2) with a cooling mantle (11) and leading to a compartment (4) with a filter (5). The duct inlet (1) is convergent to reduce gas velocity and hence dust entrainment.

Abstract: A rapping mechanism for the rapping of discharge and field electrodes in a high voltage driven electrostatic precipitator used for the cleansing of smoke laden gases from industrial plants, power works etc. The rapping effect is obtained by metal balls which run from the top of the precipitator to its bottom along a number of sloping tracks which are mounted stepwise, with differences of level, on the electrodes or on the carrying frames of same. A single ball in connection with its changing from one track to the following track, when falling freely and moving horizontally, hits both the underlying track and a stop mounted near the lower end of the track thereby causing each electrode carrying frame to receive two consecutive blows of different force so that the frame is rapped and the deposited dust is loosened and falls off. A lifting device of known type carries the balls from a terminated passage down along the tracks to a starting position for a renewed passage of the tracks.

Abstract: A rotatable drum (1) carries, and is driven by, a gear rim (3), with bevel toothing (12), via a flexible frustoconical casing (5) which accommodates distortions of the drum and absorbs axial loading resulting from the bevel toothing. Flexing of the gear rim is resisted on one side by the stiffness of the casing (5) and on the other side by a stiffening ring (9).

Abstract: A Clinker cooler has a stationary tubular body (4) with a material inlet (3) connected to a kiln (1) and a material outlet (5). Material (18) is repeatedly raised into the path of cooling air from a fan (7) by blasts of air from a row of blasters (8).

Abstract: A vertical roller mill has stationary grinding rollers which roll over a grinding path (4) of a rotatable grinding table (1), and a surrounding nozzle ring (7) for conveying and separating air. A coarse fraction of ground material is entrained upwards and radially inwards over an inclined outer wall (19) of a screen (15) and is directed downwards by an overlying guide wall (16) onto an inclined inner wall (20) of the screen (15) and hence back to the grinding table (1) for further grinding.

Abstract: A rapping mechanism for an electrostatic precipitator comprises hammers (1) which are swingable on a shaft (2) carrying a driver pin (6). As the shaft rotates, the driver pin (6) engages a surface (7) of a pawl (4), which is pivoted on the hammer (1), thus picking up and raising the hammer until the pawl (4) is disengaged from the driver pin (6) by an adjustable release tap (9). The hammer then swings back down under gravity and raps a bar (13) connected to electrodes.

Abstract: A gas swept tube mill has a rotary shell (1) supported on a bearing (5) by a slide ring (3), which is reinforced by a stiffening web plate (4). Ground material and gas pass out of the mill shell through a sieve plate (10) and openings (8) in a frustoconical connecting section (12) into a stationary casing (9). The wider end of the section (12) is of similar diameter to the shell (1), to which it is fastened, and the narrower end of the section (12) is fastened to a drive shaft (7) for rotating the shell (1).

Abstract: A gate for adjustably splitting a flow of granular material comprises an inlet pipe (1) which discharges onto a pivotal baffle plate (5) in an intermediate piece (2) overlying a circular plate which is formed with openings leading through respective hoppers (3) to respective ones of two or more outlet pipes (4). The baffle plate spreads the flow of material and pivoting of the baffle on a vertical shaft (6) adjusts the discharge of material through the various openings.

Abstract: A protective triggering system protects the thyristor switch element of a pulse generator circuit controlling a pulse operated electrostatic precipitator. The protective triggering is initiated for every pulse in the area around passage of the pulse current from positive to negative, its object being to supplement the spark-over released retriggering system so as to ensure that spark-overs occurring immediately after the current passage across zero do not cause renewed thyristor current in the absence of a triggering signal.

Abstract: A kiln plant for producing cement of other clinker from chloride-containing raw material has a kiln (2), a suspension preheater (4,5,6,7) through which kiln exit gas passes to a precipitator (8), and a by-pass conduit (11,14) through which a portion of the kiln exit gas passes via an air quenching unit (12) to the precipitator without encountering any further precipitator.