Abstract: A method for the calcination of powdery or fine-particled plaster, comprising two steps: the plaster is subjected to a flash-calcination in a calcinator and the hot plaster is post-calcinated in a reaction vessel. Post-calcination is carried out in the reaction vessel by adding humid gas, said reaction vessel not being heated. The postcalcination takes place over a long period of time, that is at least 10 times, preferably 50-100 times longer than the amount of time taken for flash calcination. Calcination takes place without expending additional energy, and the remaining dihydrate produced during the flash calcination is also transformed into semi-hydrate and undesired anhydrite fractions are reduced. The method can ensure consistency in the product quality and also increase product quality. The temperature in the upstream calcinator can be lowered thus saving more energy. The method can also be used to accelerate the ageing of calcinated plaster.

Abstract: A method for the calcination of powdery or fine-particled plaster, comprising two steps: the plaster is subjected to a flash-calcination in a calcinator and the hot plaster is post-calcinated in a reaction vessel. Post-calcination is carried out in the reaction vessel by adding humid gas, said reaction vessel not being heated. The postcalcination takes place over a long period of time, that is at least 10 times, preferably 50-100 times longer than the amount of time taken for flash calcination. Calcination takes place without expending additional energy, and the remaining dihydrate produced during the flash calcination is also transformed into semi-hydrate and undesired anhydrite fractions are reduced. The method can ensure consistency in the product quality and also increase product quality. The temperature in the upstream calcinator can be lowered thus saving more energy. The method can also be used to accelerate the ageing of calcinated plaster.

Abstract: A device for treating bulk material with a gas, the device including a grate through which gas can flow from an under-grate space to the upper side and which conveys a layer of bulk material in a conveying direction from a loading end to a discharge end. The grate has a plurality of mutually adjacent rows, each of which includes at least one bar that is elongate in the conveying direction and may be moved alternately back and forth in the conveying direction. Driving is controlled such that the forward stroke of the at least one bar of two adjacent rows takes place at the same time, while the rearward stroke of the at least one bar of two adjacent rows takes place at different times.

Abstract: A device for treating bulk material with a gas, the device including a grate through which gas can flow from an under-grate space to the upper side and which conveys a layer of bulk material in a conveying direction from a loading end to a discharge end. The grate has a plurality of mutually adjacent rows, each of which includes at least one bar that is elongate in the conveying direction and may be moved alternately back and forth in the conveying direction. Driving is controlled such that the forward stroke of the at least one bar of two adjacent rows takes place at the same time, while the rearward stroke of the at least one bar of two adjacent rows takes place at different times.

Abstract: A method for the production of hard plaster, a calcining plant, and a retrofit reactor for calcining plants. The method includes feeding plaster material, predominantly including beta-hemihydrate plaster, to a postreactor. The temperature is set to at least a calcining temperature of 95° C. during this step. The plaster material is retreated in the postreactor to form hard plaster, the beta-hemihydrate plaster being converted directly into alpha-hemihydrate plaster at a temperature above 95° C. The hard plaster can then be discharged out of the postreactor and cooled. Conversion can be carried out in the postreactor during continuous operation, and conversion of the beta-hemihydrate plaster can occur with a dwell time in the postreactor of less than 30 minutes. Steam can be externally supplied to the postreactor and the temperature and pressure in the postreactor can be regulated so that the temperature is at least 95° C. and an over pressure prevails.

Abstract: An apparatus includes a feed chamber for feeding of material from storage bunkers and a lifting device for lifting the material to a high level. The lifting device includes a delivery end to which a transport line for conveying the material away to a remote delivery point can be connected, a pressure vessel having a vertical conveyor that begins in the feed chamber and ends in a top region of the pressure vessel, and a discharge pipe beginning in a bottom region of the pressure vessel and leading out of the pressure vessel. The apparatus also includes a pressurizing device which pressurizes the pressure vessel via a first valve and activates a conveying air nozzle of the discharge pipe via a second valve, and a controller for filling the pressure vessel via the vertical conveyor, fluidizing the material via the pressurizing device, and conveying the material away via the transport line.

Abstract: A process and installation for the milling-drying and storage of brown coal. Brown coal is milled to form brown coal dust in a low-oxygen atmosphere at temperatures which are higher compared to the prior art. Then, the brown coal dust is washed with low-oxygen, dry second conveying gas and stored in a silo in a low-oxygen, dry atmosphere at a temperature of above 60° C. The installation is designed to carry out this process and comprises, for the process steps mentioned above, a mill, a dust washing installation and a silo.

Abstract: A solids distributor for injection plants includes a collecting chamber having a plurality of lance lines leading away from the chamber. The chamber has a supply connection for a solid to be distributed and is surrounded by a common wall in which a plurality of ports is formed. The lance lines are connected to the ports, and an annular gap is formed in front of the ports and along the common wall. A pressure vessel is arranged geodetically above the collecting chamber, the lower part of the pressure vessel being designed as a bunker, having an outlet providing a direct and continuous junction to the supply connection and an upper part designed as a gas space. The collecting chamber may include a central displacement body which forms the annular gap with the common wall and which may be an upwardly tapering cone which projects out of the collecting chamber.

Abstract: The invention relates to a process and to an installation (1) for the milling-drying and storage of brown coal. According to the invention, brown coal is milled to form brown coal dust in a low-oxygen atmosphere at temperatures which are higher compared to the prior art. Then, the brown coal dust is washed with low-oxygen, dry second conveying gas and stored in a silo in a low-oxygen, dry atmosphere at a temperature of above 60° C. The installation (1) according to the invention is designed to carry out the process according to the invention and comprises, for the process steps mentioned above, a mill (20), a dust washing installation (30) and a silo (40).

Abstract: The invention relates to a method for the production of hard plaster made from calcined beta hemihydrate plaster, comprising adding of plaster material mainly consisting of beta hemihydrate plaster to a post reactor (3), after-treating in the post reactor (3) for forming hard plaster, wherein the beta hemihydrate plaster is directly converted into alpha hemihydrate plaster at a temperature above the calcining temperature of 95 degrees Celsius, removing the hard plaster from the post reactor (3), and cooling down. During the adding of the plaster material to the post reactor (3) the temperature is adjusted to at least the calcining temperature, the conversion is carried out in the post reactor (3) at a dwell time of less than 30 minutes while externally adding water vapor, and the temperature and the pressure in the post reactor (3) are regulated such that the temperature is at least 95 degrees Celsius and an overpressure is present.

Abstract: An apparatus for cooling bulk material with a grate flowed through by cooling gas. The apparatus comprises a plurality of planks configured to move forward and back in the direction of conveyance and, between the planks, a sealing device having spatially separate outer and inner sealing elements. The sealing device has between the sealing elements a conveying duct, which runs along the length of the planks and on which a gas supply is configured to produce a gas stream along the length of the conveying duct. Bulk material which has infiltrated through the outer sealing element can be transported away before it can reach and migrate through the inner sealing element. The accompanying sealing effect can considerably reduce the undesirable material through-fall, while enabling the use of low-wearing seals, which provide excellent wear resistance.