DE2406372A1 - Thermally converting mixts. of combustible and non-combustible solids - using latent heat, providing gas for combustion engines etc - Google Patents

Abstract

Mixture of combustible and non-combustible solids is thermally converted further by introducing O2-containing gas in a certain concentration, the temp. and quantity at the bend between the vertical evaporating chamber and the horizontal fire chamber, to form strata of degasification, oxidation and reduction or gasification. The volatile and/or non-volatile constituents flow into the gas stream with so much heat of reaction that the non-combustible fraction is liquefied to form a film on the surface separating the two chambers, while the hot gases pass through this film and into the fire chamber.

Description

Process and device for the thermal conversion of mixtures of substances.

The present invention relates to a supplement to that in the main patent as 2: 312 71 described method and the associated device zui thermal Decomposition of mixtures of substances using the calorific values they have brought in.

The main application is characterized in that the substance mixtures Divide an enclosed space into an exhaust gas chamber and a flame chamber and that the oxygen introduced into the latter increases the combustibility of the mixture of substances converts a flue gas leaving the chamber completely oxidized and thereby the incombustible is liquefied to form a hot melt running off alongside the gas.

The present additional invention extends this method Introducing an oxygen-containing additional gas into the chamber from the exhaust steam Flame chamber bending substance mixture and through the formation effected in this way of closely spaced reaction layers of drying, Degassing, oxidizing and reducing degassing on and in front of the two chambers against each other delimiting interface, with the mixture of substances in the reaction layers Mix released gases with the additional gas and together with it through dfib to one running melt film liquefied non-gasifying remainder of the mixture of substances bead through.

Technology knows an abundance of processes in which mixtures of substances flowed through by gases and thereby thermally decomposed. The blast furnace process of the Pig iron production is just one of many examples.

There is also a large number of proposals that arise in such procedures Difficulties in selecting raw materials, caking, Xohe dust losses avoid. For example, according to DRP 387 292, the all combustion air is sucked through the melting material from top to bottom be that the liquid slag and the total amount of gas in the same direction flow through the gas generator. In this case, the hot zone is below the so-called nozzle level of the air supply, combustible components are in it burned, fly ash comes into contact with the liquid slag and becomes Part held back in her.

According to AS 1 230 164, a bath should be liquid on the floor of a gas generator Slag are maintained by which the generated gas before leaving of the gas generator must bubble through.

DRP 1 176 308 proposes a tapping gas generator in which the actual combustion or melting zone is located in the protected by I-cooling elements lower part of an annular shaft is located. The gases produced here and the liquid products should be on the way down to a forehearth between High-temperature intermediate fuel layer lying on the wind nozzle level and the gas vent measured height go through that in this intermediate fuel layer in the C02 formed in the combustion zone is largely converted to CO and that in the feed contained metal oxides are reduced.

In these examples and analogous procedures, including in the case of the present patent into consideration, it concerns an abundance of similar physical and / or chemical-metallurgical ones Single reactions.

The special characteristic and the fundamentally new of the present invention is that they such, rapidly proceeding reactions at high temperatures z .. of degassing, oxidizing, gasifying or reducing and thereby The melt which forms according to the invention is spatially determined, limited, thermally one on top of the other coordinated, large-area and yet energy-poor concentrated reaction layers assigns in close connection with a liquid melt film of the incombustible at the interface defined as the slope in terms of location.

3 such an order or mutual assignment according to the invention makes better use of high reaction speed chains made possible by high temperatures and links the associated exits of precise material and gas, supply and Removal in the sense of a so-called action machine (according to VDI magazine Vol. 98 (1956) No. 23, p. 1386) effectively with one another.

For example, as the following description shows, In this way, for the first time, a gas generator boiler can be realized, in which from goals that have long been pursued by technology can be achieved.

As such goals have to apply (see GUIZ, manual of fuel and Feuerungstechnik, 3rd edition 1962,5.542) "1. a complete elimination of all mineral Components from the combustion chamber 2. a substantial increase in the specific Performance of the gas generator, which is best achieved by avoiding dust discharge descending gasification is achieved; 3. extensive fuel universality, including both non-caking and strong caking fuels, avoiding them of grinding or other expensive pretreatment, or of a pressure that is too narrowly limited Variety choice; 4. A use of humid gasification air to control the Formation of slag to avoid the discharge of mineral components in vaporous form State and for the generation of a hydrogen-rich, easily ignitable gas. ".

In cooperation with the main invention, the present additional invention solves novel and economical but not only the best possible task of converting the calorific values of solid fuels via gasification into heat. They opened on different from this, areas of high-temperature process engineering touched new paths.

The new method is based on schematic representations and is more characteristic Characteristics of the main application described: The Fig.1 represents the vertical section K-L by an axially symmetrical device 1 for performing the Procedure, on one side. The Fig.2 shows a wedge-shaped 45 ° part of a through the plane M-N of Figure 1 laid horizontal section, plus temperatures and gas composition in% along a section line M-N or Ii-L.

The substance mixture 4 to be treated consists, for example, of combustible substances Parts b, incombustible parts a, reducible metal oxides meo and water w. It is in the vertical chamber part II of the device 1 between the outer cylinder 2 and inner cylinder 21 introduced. In this it trickles down and bends at 9 from the lower edge of the inner cylinder 21 in the horizontal chamber part III around. In the process, the mixture of substances 4 forms the separating surface 16 between the bushes substance-filled evaporation chamber II and the many times hotter flame chewer III. The latter has 12 blow-in openings 1 () for air / oxygen and / or on the cover Purge and protective gas, for example for air 13 and fuel oil 14. By means of a ceiling burner 15, the flame chamber III can be heated up when starting up. During operation can be oxygen or air 13 introduced at the periphery of the cover 12 at 9 Burn the reaction gas 17 bubbling out of the separating surface 16 to form flue gas 19 and through the heat generated in the process, the incombustible material flows away in a molten state a and lS contribute to the separating surface 16. The total effort required for this heat can be generated by exothermic heat of reaction from the indirectly heated mixture of substances 4 are supplemented by them.

The latter part is essentially due to the amount of material in the mixture 4 amount of primary oxygen bound. Is this enough and the amount of heat of reaction from the Stoffgemiscli 4 in connection with the interface heating by means of the Oxygen supply 13 3 does not stop the incombustible a molten to the drain to bring, the ceiling burner 15 must be used, The one in the flame chamber III treated gases 17 or 19 and the melt 18 flow from it through the outlet 11 in lSoden 3. So much for the main proceedings.

According to the present additional invention, this process can be regulated and significantly improve economically.

In some cases from the vertical to the horizontal bent mixture of substances 4 is oxygen-containing additional gas 6 in such a concentration, temperature and amount flowing towards the interface 16 introduced such that 16 reaction layers formed in substance mixture 1 immediately in front of the interface from which enough heat flows off to make the incombustible a molten, co-forming the separating surface 16, that means that according to the additional invention the required total heat requirement wholly or predominantly, at least is covered to a much greater extent than after the horn invention via the flame chamber III.

For example, the central ceiling burner 15 can be used during operation be shut down in principle.

The heating of the interface 16 from the flame chamber III can be restricted to those cases in which there is an oxidation of what flows into it Reaction gas 17 is desired, for example in the context of an initially mentioned Halgas boiler firing.

But you can also do without oxidation in the flame chamber III and the method as a gas generator for reactant gas 17 11 with liquid effluent of the Incombustible 18.

According to the invention, the prerequisite for this is the introduction of an oxygen-containing agent Additional gas 6 in the mixture of substances 4 in a special way and with a special objective, distinguished, for example, from the usual wind blowing through nozzles in a shaft furnace or a conventional air supply via a host.

In the present invention, the fabric layer 4 bends from the vertical in the horizontal flow direction over a metallic baffle 4 um. By this through is from a pressure chamber I to, for example, a watering can-like distributed inflow openings or slots oxygen-containing additional gas 6 in this way blown in that the material layer 4 between the separating surface 16 and quasi-parallel Part of the baffle 5 of gas channels running quasi-parallel, comparatively roughly the same length is traversed. This blowing in means loosening up at the same time of the mixture of substances 4 and thus increased flowability. This can be reinforced are by vibrating the deflection plate 5 by means of a vibrator 8 or by rotatable guide on rollers 7. The oxygen-containing additional gas 6 can pre-warmed and supplemented with steam. The baffle 5 can by a Cooling device, for example by means of tubing, against Overheating be slotted, but it can also be heated accordingly by the supply of heat from the outside at the front will.

The special objective of this supply of the oxygen-containing additional gas 6 is further characterized in that its composition, i) osierung and about Preheating or pre-cooling to the composition of the mixture of substances 4 and the tasks set thereby is coordinated in such a way that reaction layers ß of degassing, C of pre-combustion, D of reducing degassing in close proximity to form the separating surface 16. This is achieved in that, according to the invention the heat developed from the reaction layers and conveyed by the additional gas 6 the non-gasifiable a of the substance mixture 4 in front of or at the separating surface 16 for melting and should cause it to run off as a melt film. This requirement is conditional the constant flow of fresh substance mixture 4 to fill up the gas caused by the exhaust and the melting of the vacant spaces on it by virtue of its property as an embankment surface geometrically determined separation surface 16.

The path of the additional gas 6 through the mixture of substances 4 leads through first zone A of drying. It is characterized by the fact that here the temperature TA does not exceed 100 C on average until the water has completely evaporated. (See Fig. 2). This zone A is for thermal protection in front of the baffle 5. Its extent is spatially determined by the amount of water to be evaporated, on the other hand by the amount of available evaporation heat. ') hese can from the The reaction layers flow in countercurrent to the additional gas 6.

However, it can also be applied by preheating the additional gas 6 The water vapor released from the drying zone A or from an extended area A ' 20 can be withdrawn through the evaporation chamber II.

But it can also remain attached to the additional gas 6, if this is in the The sense of the process and the progress of the reaction is desirable, for example for converting into hydrogen. Zone A can also contain water or water vapor may be added, optionally to protect against an excess of the reaction layers heat dissipating to the outside. The extent of the drying zone A or A 'is therefore influenceable. Its limit is marked by the fact that with the cessation of the den Temperature rise inhibiting water evaporation layer B (immediately increasing Temperature TB) begins. Highly volatile constituents, vapors containing tar become gaseous free. In temperature range between 350 and 450 C bitumen becomes liquid and causes the tendency of the mixture of substances to cake together to be gas-impermeable will.

According to the invention, that which flows through the degassing layer 8 acts on this Additional gas 6 effectively counteracts this. It takes the degassing flat components up, promotes it from the place of origin and thus increases the degassing speed, at the same time, this reduces the depth of the degassing layer to be taken through by the additional gas B.

The additional gas whirls through the mixture of substances, making it even in it the heat distribution, it leads to higher temperatures and thereby destroys the Tendency for the mixture of substances to stick together. Strong baking fuels are also used Can be used by decomposing the bitumen, tar-containing vapors are overheated and do not condense.

In the course of the rapid rise in temperature, reach TIB (see Fig. 2) Mixture of substances 4, additional gas 6 and degassing products quickly reach the ignition limit of the a earliest vital component. This starts oxidation with the oxygen of the Additional gas, the reaction layer C of the combustion. In this the temperature rises TC steeply up to an altitude point Tm. This maximum value is due to crowding of diffusion in a narrow view C, owing to the concentration of the Developed heat in a confined space with such stratified combustion (also with conventional Processes, such as incineration on a traveling grate or in the case of #auges internal) high, reaching 1600 OC and above. The difference compared to the procedure after the invention lies in the fact that such conventional methods are so high Temperatures must prevent the incombustible from melting, because through Slagging of the material layer, gas penetration and thus progress of the reaction to a standstill come. Therefore, with this conventional layering process, even with induced draft sintering, the temperature below the maximum value T as quickly as possible m below the melting point of the incombustible, compare TK in Fig. 2.

In contrast, the present invention demands one as possible effective use of high temperature peaks T + Bie temperature m TD in the reaction layer D immediately following the combustion layer C (the Gasification of the degassed carbon coke by means of the primary combustion generated carbonic acid) must not be below the melting point of the invention to be melted Ash a absinlcen.

TD decreases as a result of the energy requirement of the gasification equation CO2 @ C = CO - 38 400 kcal (1). So that the temperature required for melting TIII is not fallen below, must occasionally from the Flammenicamrner, as already mentioned, heat supplied and the temperature curve according to TIII, therefore more likely again be raised. The iteduction according to equation (i) is temperature-dependent. she runs the faster the higher the temperature TD is. Mui3 this value according to the requirement of the invention to ensure the melting, lie high, so it inevitably has rapid reduction and thus fast reaction layer D. As a consequence, the invention inevitably eliminates the reaction layers the combustion C and the degassing closely tied to the separating surface 16, must be also inevitably adapt to their position and surface.

FIG. 2 describes this in a representation known per se on the course the temperatures T in OC and the gas composition in FIG. 6 along the path of the additional gas 6 through the fabric layer 4 or the heatitionsschichten from E-L. With the insert the ignition and combustion in the layer @ decreases, which has remained practically unchanged until then O2 content in the additional gas down to zero at the end of the combustion. Correspondingly increases the proportion of the carbonic acid CO primarily produced by the incineration? from zero a maximum value. With the start of the reduction according to equation (1), the C02 component goes down back to zero, but the proportion of the finally generated reducing gas increases CO to a final value. It characterizes the composition of the melt layer E or gas 17 bubbling through the separating surface 16. In addition, there is hydrogen and nitrogen.

The course of the temperature curve has already been discussed.

The amount of oxygen-rich additional gas supplied in the unit of time is decisive for the intensity of the burning in the heat layer LS C, accordingly also for the position of the reaction layers at the interface. It determines performance and throughput of the process, i.e.

the amount of in the unit of time per unit of the shift surface area decomposed substance mixture. Experience has shown that it is superior to conventionally in the case of rust burning achievable values of about 300 kg per m² and h of combustibles. This follows from the course of the procedure according to the invention, in which Degassing and gasification from reaction layers large surface and shallow depth occurs at high working temperatures and under a final filtering; Jchielzeschicht. This allows high wind throughput without the fuel layer being blown open or blown through, which sets limits in the event of rust burns.

If the process is interrupted by switching off the additional gas 6, stops the reaction in layers B, C and D, thus melting away the incombustible spontaneously. In this case, the combustion layer C, which generates the heat of reaction, is from enveloped on both sides by more or less insulating neighboring layers and Experience has shown that it stays hot and glowing for a long time. Sets the flow of the auxiliary gas on again, ignition, combustion, and increase quickly begin again from shift C. the temperature, melting into the incombustible. so ì {alas fresh Mixture of substances. Thus, the method of the present invention is by metering of the additional gas can be easily regulated.

The schematic representation of FIG. 2 does not take into account that according to the invention Freeing volatiles in the degassing layer B and mixing them with the additional gas 6. Thereby and with the further flow into hotter layers and additional ones Mixing with degassing products from layer D results in cleavage and cracking reactions initiated according to the invention more easily and effectively than, for example, according to the in DRP .526 420 for mixing distillation gas and fuel gas for metallurgical Purposes of the proposed method.

Vapors containing tar are decomposed and, for example, methane is added CH4 + 1/2 02 3 CO + H2 (2) to one for the reduction, for example of iron ore welcome reducing gas converted. So that in the method according to the present Invention an effective prerequisite for reducing what is contained in the mixture of substances Metal oxyd meo created, also for fine-horned raw materials and gas-rich coal. If technical oxygen is used instead of air, the concentration increases the heating layers in precise, isolating layers of the mixture of substances outwardly shielded chambers particularly advantageous noticeable.

In such a reduction method according to the invention, for example the production of pig iron in connection with valuable CO instead of dust-laden Blast furnace gases leave hot molten metal, liquid slag and hot dust-free Reaction gas in the formation state in aftercare facilities, z. B. in Siemens-Martin ovens without great heat loss and directly transfer further process there.

The same applies mutatis mutandis to the reducing melting of glass mixtures in premelting furnaces and post-treatment in tank refining furnaces.

The rule of invention, the incombustible to the molten Bringing drainage can be reduced by adding its melting point - make it easier to add additives to the mixture of substances 4. this can also increase the melting point should be aimed for if this, for example, according to DRP 759 416 when gasifying salty brown coals prevent the premature evaporation of alkalis target.

The degree of integration and melting of fine particles entrained by the additional gas 6 in the melt film 18 can achieve such high values in the process according to the invention that the reaction gas bubbling through to the flame chamber III can be further processed without any special additional dry or wet dust removal bind themselves into the melt by melting chemically absorbing, for example, basic additives.

The present method thus opens up new manufacturing possibilities one for example directly for the operation of internal combustion engines, Gas turbines, suitable power gases. not only do the advantages of one thing play a role here Relatively simple separation of the ashes matter, but also the Possibility of setting the pressure u "'which the process by blowing in the additional gas is put to multiply and so relatively easy to get out of coal a hot pressurized gas to come.

Provide working method according to the invention, in particular in connection with the main proceedings, a promising possibility today, so far Usual shaft and low-level furnace processes using a layer furnace process replace, especially when it comes down to it, instead of air with technical Oxygen to work.

For example, the one previously carried out in the blast furnace can also be used Reduction of phosphate to phosphorus according to the relationship Ca3 (PO4) 2 + 3 SiO2 + 5 C = 3 CaSiO3 + 5 CO + 2P (3) in which one also burns of the coal used only until it burns up, until CO can go, according to the rules of the present invention more precisely. The one in the conventional process the further processing to phosphoric acid is a highly disturbing high dust content in the reaction gas goes back to a fraction, as well as difficulties with durability conventional ceramic lining of the reaction vessels.

The same applies to piercing temperature procedures previously carried out in the Dr.htrommel, for example for the production of sulfuric acid from anhydrite at the same time adjust the melt to Portland cement-I; left. The splitting of calcium sulphate according to the equation 2 CaS04 + C »2 CaO +2 2 S02 + L'02 (4) and the required Melting of aggregates can be more precise according to the present invention and carry out with considerably less dust generation.

These examples can be multiplied. The increasing importance of being more responsive energy-intensive high-temperature process, the use of oxygen instead Air, the need to pay more attention to environmental protection requirements, So far neglected raw material sources, for example ballast coal, should be taken into account underline the fundamental importance of expanding the possibilities of the main process through the present additional process, especially when processing of mixtures of substances which, via the gasification of solid fuels, lead to liquid drainage non-gassing Realction participants should lead.

Claims (17)

P a t e n t a n s p r ü c h e 1. Process according to main patent OS 2 312 719 (additional patent) for the thermal conversion of mixtures of combustible substances and non-combustible, preferably solid, components, by utilizing the from their introduced calorific values, additionally characterized in that in the bend the bending over from the vertical evaporation chamber to the horizontal flame chamber Mixture of substances flow-promoting, preferably oxygen-containing distributed over a wide area Gas is introduced in such a concentration, temperature and quantity that that close to the invention both chambers limiting interface reaction layers of degassing, oxidation and reduction or gasification are formed in close succession, which are volatile and / or volatilized constituents in the gas stream along with as much heat of reaction let flow in that the non-gasifiable incombustible to one at the Trennfläcbe running melt film is liquefied, through which the hot reaction gases to Bubble through the flame chamber. 2. The method according to claim l, characterized in that by the Formation and position of the reaction layers adapted to the separation area converting Also fine-grain, unclassified and / or baking ingredients with high throughput is made possible. 3. The method according to claim 1 or 2, characterized in that the Mixture of substances that change the melting point of the incombustible are mixed in, which filter the solids from the bubbling through Favor gas. 4. The method according to any one of claims 1 to 3, characterized in that that the mixture of substances are mixed in with melting aggregates, which the chemical Binding of the melt to gaseous to be filtered out of the gases bubbling through Components such as sulfur, chlorine, improve. 5. The method according to any one of claims 1 to 4, characterized in that that water or steam is added to the oxygen-containing additional gas. 6. The method according to any one of claims l to 5, characterized in that that after degassing and / or gasifying from ash-containing solid fuels in the Melt of the incombustible pre-filtered hot fuel gas is used as a Fuel gas in internal combustion engines is made particularly suitable that the working pressure of the method is increased many times over, for example by corresponding Increasing the oxygen-rich make-up gas sine pressure. 7. The method according to any one of claims 1 to 6, characterized in that that ores are added to the mixture of substances, which are mixed with carbon Formation of carbon dioxide is reduced to its metals, being the liquid metal as well as the liquid slag from the flame chamber in subsequent post-treatment processes, for example Siemens-Martin ovens, can be forwarded. 8. The method according to one of the language 1 to 7, characterized in that that from unclassified ballast-rich coal one when beading through the separately Run-off snout of solids and / or corrosive gases such as sulfur or chlorine so far pre-cleaned raw gas is generated that it is immediately afterwards Can be used for generation in boiler furnaces and / or industrial furnaces. 9. The method according to any one of claims l to 8, characterized in that that degassing gas-rich mixtures of substances, especially coal, with gasification of the flammable Remnants and melting of the incombustible are combined in such a way that a special for chemical high-temperature digestion processes, for example from phosphates and Sulphates, pre-filtered in the melt, suitable for further processing Raw gas is obtained. 10. Device for performing the method according to one of the claims 1 to 9, characterized in that the proposed according to the main patent OS 2,312,819 The device is supplemented by a device for blowing in oxygen-containing, also preheated additional gas and / or steam in the mixture of substances at the Bending of the material flow from the vertical to the horizontal flow direction. 11. Device according to claim 10, characterized by a, for example For air injection perforated or provided with slits, guiding the material flow or conveying metallic baffle. 12. Device according to one of claims 10 and 11, characterized by a flow of the substance mixture which has already been improved by the air injection additionally conveying deflection plate through single movement, for example through vibration, reciprocating pushing or rotating motion. 13. Device according to claim 10 to 12, characterized by the Possibility of being touched by the Stofistrom flowed through by the blow-in luit Part of taking off heat by means of forced cooling or heat by means of special heating to feed. 14. Device according to claim 10 to 13, characterized in that that the supply of the additional gas or the additional lift according to quantity and / or distribution can be regulated, for example by subdividing it into individual elements on the circumference an axially symmetric system. 15. Device according to the claims or according to one of the claims 10 to 14 characterized in that the co-determining the working pressure of the process Blowing pressure of the additional gas up to the order of magnitude of the blowing pressure on power gas generators for internal combustion engines can be increased. 16. Device according to one of claims 10 to 15, characterized in that that they are equipped with a steam generating system or a corresponding special device, for example a melting furnace or a gas aftertreatment interconnected and combined in terms of lines to form a structural and operational overall facility is. Considered publications German patents: 387 292, 526 420, 759 416, 1 176 308 A S 1 230 164 VDI magazine 98th year (1956) H. 23, p. 1386. loo. Year (1958) H. 17, Sa ##### 725/735, Stahl und Eisen "80. Volume (1960) H.7, p.397 / 407.