DE713339C - Develops for rapid gasification of agitated carbide with the production of dry hydrate - Google Patents

Description

Developer for rapid gasification of moving Cdrbids while obtaining dry Hydrates The invention relates to a developer for the rapid gasification of agitated carbide while obtaining dry hydrate lind avoiding overheating caused by the Use of high-frequency vibrating sieves at temperatures above i io ° marked is.

While the previous methods or developers for carbide gasification either worked in such a way that wet lime sludge was obtained or one was dry when it was obtained and powdery hydrate, the carbide, in rotating full-jacket turrets leln or sieve drums or on rotating plates, o. The like. Decomposed, is according to the invention a very rapidly oscillating movement of a sieve or sieve-like Soil for the decomposition of the carbide and the constant liberation of the carbide surface Hydrated lime made usable, but, as was further found, at temperatures must be worked over i io °. Only compliance with these temperature conditions according to the invention Surprisingly allowed the reliable use of high-frequency vibrating sieves for the gasification of carbides. As such, calcium carbide is used as well as others Alkaline earth carbides or alkali carbides or masses containing them are used. the Sieve movement can be a translational oscillation or a circular or elliptical one Vibration o. The like. Represent the at least one component upwards is directed. It is essential here that very rapid vibrations, i. H. High frequency vibration vibrations come into use, z. B. Oscillating movements of the sieve, sieve bottom or the like of over iooo, / minute, e.g. B. 1 ¢ 0o to 1500 / minute. In this way, the goods to be gasified are not only placed against each other, but undergoes a very fast dancing movement, which causes the abrasion of the formed dry hydrate particularly quickly, as it were at the moment of the occurrence of the Hydrates takes place and therefore always new carbide surfaces for gasification To be available. In addition, one is not particularly fond of carbide, z. B. powdered or dusty carbide. , bound, but can also be lumpy or granular, advantageously z. B. also unsorted carbide of various grain sizes use. Instead of mesh sieves or the like, harp vibrators or the like can also be used Sieve devices used mechanically or on any other Art. B. electromagnetically, be excited to Schn-ingen. With electromagnetic High frequency vibrators For example, vibrations of 3,000 / minute can be achieved.

The gasification takes place essentially by means of water vapor, which in the Co-current finitely with the material to be decomposed or better in counter-current. The water vapor can, for. B. generated entirely or partially by the heat of reaction itself be done by placing a water jacket in the decomposer, either supplies preheated water or direct steam. The latter can also be done by spraying of the carbide material located on the sieves are generated @ with water, with the Production of a dry residue, however, it should be noted that at no point the temperature of the sprayed material falls below i i o ° C. This is the only way to succeed the gasification according to the invention with the achievement of an absolutely dry hydrate.

The resulting powdery hydrate is completely hydrated and of very great delicacy. This makes it z. B. especially on granulation processes excellently suited, due to the very small grain sizes and the complete Dehydrated moldings obtained even without the application of compression pressure will. The ability to react or reactivity is due to its delicacy particularly large, so that the material for chemical reactions such. B. for carbide formation or cyanamide formation with bound nitrogen and carbon-containing gas mixtures and the like well suited. Through intermediate sieving or classifying processes, e.g. B. Wind sifting, a material of increased uniformity and purity can be obtained.

The nice process is particularly suitable for high-performance gasification of carbides in relatively small apparatus, and that is a special one significant advantage. If larger masses are to be gasified, different vibrations will result o. The like. With the same or different, in particular in the direction of the material path decreasing opening width arranged one above the other or one behind the other. That on the Bursting sieves with a large opening width conspicuously coarser granular material then falls after partial Vergasuhg on the underlying sieve trays of smaller mouth and is peeled down as a dry hydrate. The mode of operation becomes discontinuous or preferably designed continuously. If high-performance gasification is desired, it is also possible it is not necessary to put all of the carbide material on the top sieve, but there can be task points for different ones located below or on top of each other Sieves can be provided, the slot openings of the sieves can also alternately be larger and be smaller and the like. According to the invention, it is only essential that the sieves are very with rapid linear or circular, elliptisclic or similar oscillations at least one upward component are added and that to be gasified Well on the sieve trays, sieves or the like. Is held in fast dancing motion.

The new developer has particular advantages in rapid gasification of carbides. Whereas in previous forms of decomposition, the heat of reaction was dissipated always caused great difficulties, this disadvantage is in the new invention by installing cooling devices above and, 'or below or between the Seven easy to get rid of. This particular advantage is related to the fact that .in place of rotary movements, such as. B. with drums, with mostly difficult to close holding water connections short 'straight or short rotational oscillations be used, with built-in cooling surfaces, cooling pipes and the like elastic connections can be easily attached. In particular, those with any gaseous or liquid means operated cooling systems advantageously between the vibrating sieves permanently installed or fixed cooling devices next to moving ones used. In the latter case, z. B. the equipment of the vibrating sieves and / or the screen frame or sockets with cooling devices, e.g. ß. water-flowing Pipes, double floors and the like have advantages in high-performance gasification. It can also any fast oscillating cooling surfaces or cooled oscillating screens or the like. Find use.

Above or below the vibrating sieves or above them Sieves can also be attached to spraying devices for liquid water, the amount of water being regulated so that liquid water is only over i i o ° C meets hot goods. Due to the effective, easy to attach between the sieves Cooling devices and gasifying, on different screen surfaces is one particular rapid gasification possible, so that advantageously high throughputs are achieved without overheating and its harmful consequences, such as polymerizations and the like are to be feared. those at too high a temperature a yellow to brown-black coloration of the hydrate can be seen. This is advantageous safe operation despite particularly high throughput and fast gasification guaranteed. In general, temperatures above aoo ° should be avoided.

The decomposition by means of steam or liquid Water can be done so that the steam in cocurrent and / or in countercurrent or the carbide material hits partially in cocurrent and countercurrent. The steam guide can also be done transversely to the material flow, e.g. B. the good by one on top of the other arranged sieves fall down vertically and the water vapor on one or more Places are diverted laterally and more or less parallel across the sieve surfaces to brush. The outlet point for the developed aoetylene can be on the side of the fresh goods supply or in the vicinity of the hydrated lime outlet or at any other point be; acetylene can also be withdrawn at several points. Proves beneficial an at least partial countercurrent flow of the water vapor to that to be gasified Good with the acetylene deduction on the fresh side. This way the hot, almost completely gasified good water - b-zw. Steam in high concentration while that. Fresh food comes into contact with steam of a lower concentration, causing overheating can be avoided particularly easily. The water vapor can, for. B. also by nozzles of the hot, about 130 to aoo ° warm hydrated lime can be produced.

An Ausform has also proven to be advantageous in which on the vibrating screens loose balls, pieces i or other moldings made of materials with a high coefficient of thermal conductivity and / or high thermal capacity, eg. B. Metalllmgeln, ceramic body high Ab, abrasion resistance o. The like., Are applied. This not only supports the effect of the vibration oscillation, but also when spraying the carbide-containing masses with liquid water on the vibrating sieves, for. B. by applied metal balls u. Not only does this result in less reaction heat per unit of space, but it is also dissipated or absorbed more quickly. Instead of metal moldings, moldings made of ceramic masses or natural materials and the like can also be used, e.g. B. find small stones, use. The abandoned amount of these foreign bodies is z. B. about one or two layers, but much more or less can be used.

Another useful embodiment of the invention is those provided above and / or below the sieves or between the sieves Kühlvo @ ri-ichtun>, en as pipe systems or the like suitable for steam generation. It can e.g. B. tube bundles or surfaces arranged in the vicinity of the sieve surface, pockets or other pockets provided with openings for the material to be gasified suitable cooling surface systems are used to generate steam. In this way the temperature in the vicinity of the sieves is constant at the evaporation temperature of the water is kept constant at 100 ° or under excess pressure when steam is generated is above 100 °. The water vapor generated can be used to gasify fresh goods or can be used for other purposes.

It is indeed a cycle process for the formation of carbide and gasification of the same known with sieving off the hydrate formed, however, with this no pieces made of carbide through and through, but pieces of oxide on their surface by treatment with hydrocarbons superficially thin carbide layer has been formed. This thin, superficial layer of carbide on pieces of alkaline earth oxide is converted to acetylene by means of steam on a conveyor belt decomposed, and after decomposition, that formed superficially on the pieces of oxide Hydrate sifted out on ordinary sieves, while those that have not yet been carbide Oxide pieces are returned to the carbide formation process, where they become superficial again coated with carbide. Since this is only a thin layer of carbide on pieces of oxide acts, the problem of controlling the heat of reaction does not arise here In addition, the decomposition to acetylene already occurs on the conveyor belt fine distribution of the carbide-containing pieces of oxide. From a processing of Carbide through and through pieces exclusively on high frequency sieves is out of the question in this procedure. With another. Procedure is the temperature kept in the carburetor at about 100 ° C or a little higher, d. H. possibly a few degrees above 100 ° C. On the other hand, it has been found that using high frequency vibration pulls. the temperature for safe working and avoidance of clogging of the sieve not at about ioo °, but must be kept above i io °, z. B. at i 5o '. Just this is how the operationally reliable use of high-frequency vibrating sieves and their attainment succeed an absolutely dry hydrate, while in the known process the hydrate still contains up to 15% moisture. It is also a facility for regulation the temperature of superheated water vapor known by injecting water, at the latter with the mediation of bodies of large surface area, such as metal balls, rings or the like, brought into contact with the superheated steam will. Here, the temperature regulation or distribution between the injected Water and the superheated steam take place, but not between the injected Water and pieces of carbide to be decomposed, i.e. solid particles that are between the packing - mixed with these - lie, -wherein the temperature of the solid particles is to be regulated. According to the invention, the latter succeeds in a satisfactory manner only with simultaneous Movement, d. H. when moving on the high-frequency vibrating sieves. Through this the removal of the formed hydrate from the surface of the carbide particles becomes effective supports.

The new developer is not only suitable for the gasification of calcium carbide and the like, whereby, in addition to sorted goods, unsorted goods in particular can also be processed, but it is also advantageous when degassing and hydrating carbide-containing materials such as B. raw calcium cyanamide and the like., Used. Example i On a net-like vibrating sieve with a mesh size of 1 mm, which was set in rapid, approximately elliptical oscillations of 1200 to 140o / minute and was built into a developer, C.alciumc.arbid of about 5 mm in size and below was passed through in countercurrent Water vapor decomposes. The lower part of the apparatus had a temperature of 10 to 120 ° and immediately above the sieve of around 10 °. The withdrawn acetylene is high percentage. The material that fell through the vibrating sieve consisted of hydrated lime of a completely dry and fine powdery consistency. It was broken down into the following grain sizes by air sifting and showed the following composition, ^ 9.5 o, ü finer than 0.03 with z, q., [% Between 0.03 mm and 0.06 nrt, 1.5% between 0.06 mm and 0.09 mm. 14.6% greater than 0.09 now. Almost 85% of the material was therefore, in spite of the 1 mm sieve size, finer than corresponds to a 10, ooo mesh sieve; this effect is due to the rapid vibration. Example z In another. Similarly designed trap, two vibrating vibrating screens with a width of 1 mm and 0.05 mm were arranged one above the other, namely first a harp vibrator and then a finer mesh screen; the hydrated lime had the following sieve composition after sieving 83 finer than corresponds to an io ooo-: VIaschen sieve, a coarser than corresponds to an io ooo mesh sieve, but finer than a q. goo mesh sieve, 1g residue on 4th goo mesh sieve. The dry hydrate was freed from the coarser components by air sifting, corresponding to the 49oo-mesh sieve, the coarser components containing a greater proportion of the impurities. The sifted dry hydrate had the following grain composition: 2% residue on 10000 mesh sieve. 98 ° 7o passage through ioooo-Masclien-Siel).

Claims (3)

PATENT CLAIMS i. Developer for the rapid gasification of moving carbide while obtaining dry hydrate and avoiding overheating, characterized by the use of high-frequency vibrating sieves at temperatures above it ". 2. Developer according to claim i, characterized in that several optionally high frequency vibrating sieves of the same or different types, provided with cooling devices, in particular in the direction of the flow of material, diminishing widths one above the other are arranged. while above, below or between the sieves as a steam generator trained fixed pipe systems o. The like. Are attached, their under utilization the heat of reaction obtained steam e.g. B. with countercurrent flow to the material for decomposition is used. 3. Developer according to claim i and characterized in that on the high frequency vibrating screens loose balls. Pieces or other bricks Substances of high thermal conductivity and: 'or high thermal capacity, e.g. B. metal balls, ceramic body with high abrasion resistance. Stones or the like are applied.