Abstract:
A catalyst for use in a process for the removal of nitrogen oxides from exhaust gases contaminated with dust in which the process uses ammonia. The catalyst is made of a material which is easily disposable. Furthermore, the catalyst should be completely used up in the catalysis. The catalyst comprises individual ceramic bricks with a porous surface, and passages therethrough for the flow of the exhaust gases. The bricks exhibit a resistance to abrasion which is designed so that the dust of the exhaust gas which flows through the passages erodes the catalyst surface, thereby reactivating the catalyst. The exhaust gas carries the dust and the eroded material along with it.
Abstract:
In a process for the reactivation of a catalyst, which is used for the removal of NO.sub.x, oxides of nitrogen, from exhaust gases, the catalyst should be capable of easy reactivation. For this purpose, when the catalyst starts to lose its activity, it is exposed in a reducing atmosphere to a carbon monoxide current. In an apparatus for the execution of the process, the catalyst is placed in two separate chambers. The carbon monoxide stream is directed alternately to both chambers.
Abstract:
Plastic composition which can be processed into a fire-resistant material, use thereof, and process for its production, which process comprises mixing ceramic fibers with a substantially dry organic bonding agent to produce a first mixture, mixing the first mixture with water to produce a second mixture, mixing the second mixture with clay to produce a third mixture, and mixing the third mixture with an aqueous solution of an organic bonding agent to produce a fourth mixture, with the proviso that the ceramic fibers account for at least 74% by weight of the solids content in the plastic composition.
Abstract:
Granular, fire-resistant material, use thereof and process for its production, which process comprises mixing ceramic fibers, a refractory material such as clay, a phosphate bonding agent and water, to form a substantially uniformly dispersed mixture, compacting the mixture by a volume coefficient of at least 3, subjecting the compacted mixture to heat-treatment, and granulating the thus heated product.
Abstract:
A plurality of individual control units transmits control signals, each to a corresponding controllable object. The control signals from the different units are arranged in a predetermined sequence, each control unit having a self-address which signifies its position in the sequence. The self-address is stored in the unit and transmitted in the control signal. Each unit has a receiver receiving the control signals from the other units and deriving an external address signal therefrom. The external address signal presets an address counter. After termination of the received control signal, pulses are added to the address counter until its counting output is equal to the self-address of the unit. The unit then transmits its control signal, but only if no new control signal is being received. Since the self-addresses increase as the position in the sequence increases, the presetting of the address counter causes units having a lower self-address than the preset number to be blocked. Self-address changing circuits are provided to allow incorporation of a unit or units into a different sequence.