FI113563B - Method and apparatus for improving heat retention and light weight of a rotating tubular heating drum intended for high temperature heating materials - Google Patents

Description

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A method and apparatus for improving the temperature economy and lighter weight in a rotating tubular heating drum for heating the material to high temperature.

The present invention relates to a method according to claim 1 and to a device for heating a material to a high temperature in a heating drum, wherein the improvement is to improve the temperature of the heating drum and reduce its own weight in a horizontal or inclined hollow longitudinal tubular heating drum the feed (A) and the heat treated material at one or more ends of the drum (B) and the heat source (C) to produce heat. It is accomplished in accordance with the invention in that the rotary heater drum is made of a medium-cooled refractory chromium-nickel steel for temperature equalization, temperature rise and heat conduction.

Heating the material to high temperature in a rotating hollow horizontal or inclined drum is known per se. In operation 20, there are many plants in which a rotating hollow tubular drum is used to heat the material to a high temperature for a variety of applications. There are many patents on the subject, of which the following U.S. Pat. Nos. 4,634,634, 4,952,147, * «·; US 4,569,659, US 4,557,688, US 4,932,863, US 4,289,479, US 4,290,750, US 4,906,183 US 4,259,062. A mobile incineration plant is disclosed, for example, in: US 3,682,117, US 3,882,800, US 3,728,976, US 3,938,450 ... and EP 0 892 870 B1. Application of heat-resistant ceramic material: ..; * by spraying on the inner surface of an incinerator is disclosed, for example, in US Patent 4,224,083. Thermal insulation of rotary heating furnace with ceramic fiber

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* · · · '30 on the backing layer is disclosed, for example, in U.S. Patent No. 4,932,863. Mixing, raising, and dropping of the fluid to be passed through the hot v: gas by means of a lifting wall is disclosed, for example, in U.S. Patent Nos. 5,772,327 and 4,106,114.

2 113563 In the present application, the term "high temperature" means a temperature of at least 200 ... more than 2000 ° C. In this application, the term "heating the material to high temperature" also means burning the material. In this application, the term "ceramic thermal insulation 11" refers to a synthetic thermal insulation melting at a temperature of about 1000 to 1800 ° C. For example, US 4,405,723 discloses ceramic fiber wool and its manufacture.

In this application, the term "heat source" refers to a burner for burning fuel or an electric heater. Common sources of heat include, for example, various types of oil, coal, and natural gas burners where fuel is usually burned without oxygen. even pure oxygen that burns with the fuel to produce heat.

15 Reducing the proportion of normal air nitrogen (about 78%) in combustion saves unnecessary and harmful heating of nitrogen and energy consumption in the combustion process. Nitrogen does not contribute much to the production of heat but consumes heat. On the other hand, oxygen-enriched air causes intense combustion in the burner and a rapid rise in heat when nitrogen and argon are not slowing the combustion. 20 operations and consuming heat.

. ·: *. When burned with oxygen-rich air, the heat of combustion easily rises so high ···. but that the strength of ordinary steel metals is reduced if there is no ceramic layer: ..: from which layer of thermal insulation. It can withstand temperatures up to 1800 ° C or less.

25 Because of this disadvantage, for example, in many thermal power plants, the most valuable high heat is left untapped when steel-based materials can withstand •: ·· * only continuous heat below 1000 ° C. With pure oxygen, the combustion temperature can be raised to about 3000 degrees, for example by burning acetylene.

: Improved heat resistance of the drum material to achieve a burning temperature reduction. 30 improve the maximum heat by raising the fuel's energy content. can be better utilized. The use of normal, nitrogen-rich air in combustion also has the disadvantage that besides the cooling and diluting effect of nitrogen, combustion also produces environmentally harmful nitrogen compounds, so-called NOX compounds, at high temperatures.

By using electric heating instead of incineration, it is possible to avoid completely heating the nitrogen of the air during combustion. This also eliminates the large amount of waste gas waste gas with its environmental problems and cleaning needs. The problem with modern technology is the high temperature resistance of the steel drum material. Due to the chromium-nickel-steel heat-drum material reflecting the heat rays, the rotary heater drum only needs approximately the amount of oxygen needed to heat or burn the heat-treatable material itself. The current oxygen surplus of 10 ... 20% may no longer be needed in the future. The amount of gas to be heated is substantially smaller.

15 Only oxygen, approximately 21% of the air, is needed for combustion. The rest of the air is nitrogen and argon, which is unnecessarily heated for combustion. This 79% of the air only consumes energy, regardless of the type of heating. Partially reducing the passive air portion in the heater drum substantially reduces the energy cost of the heater. This can be accomplished by supplying to the combustion 20 additional pure oxygen or by electric heating if the materials have sufficient heat resistance. Electric heating is obtained in a mobile form, for example, ·: ·. why with the movable internal combustion engine set, ie the small movable. sähkövoimalalla.

• ·. '* ·; A further disadvantage of known heating methods in a rotating heating drum is that the steel metal drum is coated with a heavy •: · · insulating layer, such as brick cladding or ceramic casting.

• '': The insulating layer is usually made of ceramic square bricks that: lean against each other as shown in Figure 1 in the longitudinal and transverse directions. Insulation layer »· * ·. · · ·. 30 protects the steel drum from overheating due to radiant heat from the burner. In current heating drums, the aim is to prevent heat transfer by passing along the drum structures in different directions. Adding to this is the ceramic lining by bricklaying rectangular bricks 4 113563 to each other. The small gaps between them prevent heat conduction along the drum in the longitudinal and transverse directions. Most of the heat generated in a heat source is transmitted by radiation, which usually proceeds in a wave motion in a straight line without any medium. Radiation energy turns into heat once again when 5 substances are encountered again. In the radiation form, the heat can be reflected like a mirror on a chromium-nickel steel sheet and, as at present, is not absorbed by the heavy ceramic layer.

The heavy ceramic thermal shielding layer is completely useless in terms of heat treatment itself, but generates most of the weight of the equipment. Substantial removal of the ceramic layer is important to reduce weight. Particularly in mobile high temperature heating methods and devices, losing weight is beneficial. This reduces transport costs and allows the fleet to move even in difficult locations. The size of the rotary heater 15 is also easier to get smaller, or easier to carry on the road among other traffic.

The new furnace solution does not attempt to prevent the conduction of heat in general, but, on the contrary, surprisingly promotes the passage of heat by conduction along one longitudinal long drum tube. Heat conduction along the drum length causes the hot drum points to be cooled. *: ·. along the drum from the colder parts of the drum. The drum itself will then heat. as a driver by conduction between the hot and cold parts of the drum as the temperature ....: the crests tend to level off. The thermal conductivity of chromium and nickel is better 25 than that of steel. Chromium and nickel play a significant role in the new drum feedstock. The refractory chrome-nickel-steel material withstands •: · ·: the required thermal stress.

A: A new drum solution is not surprisingly usually not expensive at all and

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. * · *. 30 heavy insulators because they are not needed. Drum Thermal Insulation. can be easily accomplished by venting the interlayer in the drum structure as shown in Figs. Of course, a traditional ceramic wool coat is available as needed, if necessary.

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The high radiant heat generated by the burner or other heat source heats all surfaces it encounters. In existing heating drums, much of the radiant heat is absorbed and irreversibly passed through the ceramic liner 5 layers to other structures, and thereby wasted for the actual heating purpose. Only that portion of the radiant heat is useful, which encounters the material to be heated, such as a particle flying in the combustion gas. Much of the energy now passes through the target material to be heated.

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The smooth chrome-nickel-steel drum surface, on the other hand, acts like a mirror and effectively reflects the radiant heat from the furnace wall back to the furnace and the material to be heated. The curved chromium-nickel-steel plate on the surface of the drum acts as a curved mirror, whereby the reflections of the radiant heat of the burner 15 are concentrated near the central axis of the drum, where a large concentration of heat is focused. It is then in the center of the drum and not at the edges, which may be due to material other than the target heatable material. The chrome-nickel-steel drum can work like a traditional heating drum, but without the ceramic liner and its weight.

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The specific weight of the rotating metal heating drum is high today, made of heavy steel with a density of about 7.85 kg / dm3. Rotating tube-.1 ··. the weight of the earth heating drum rises very high due to the combined effect of the steel structure and the ceramic flow .... The structure must be dimensioned for a large 25 own load and its dynamic stresses. Due to the brittle and heavy ceramic heat protection, it is now necessary to keep the furnace rotation speed low: eg: 2 ... 7 rpm. Industrial furnaces for large mass production furnaces generally have internal diameters of 1.0 ... 4.5 m, but smaller:! ·. there are peaks and larger ovens. Existing steel drums have material thicknesses. · ··. 30 generally for steel 10 ... 50 mm, resulting in a high specific weight of the structure, • · without brick lining.

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According to the invention, by making the heating drum a surprisingly expensive refractory chromium-nickel steel sheet without heavy ceramic liners, the weight of the heating drum in the structure is substantially reduced. The reflective and heat-resistant drum material allows the heat to be returned to the material to be heated. At the same time, the temperature of the rotating drum furnace can be increased due to the refractory material, which is also corrosion resistant and stainless. As with traditional ceramic coatings, the drum walls no longer absorb heat. The weight of the thermal shielding layer is completely eliminated or substantially reduced. Today, the weight of the ceramic brick thermal insulation layer is more than half the weight of the entire furnace. The oven made of chrome-nickel-steel plate is substantially lighter. The heat resistance is of the same order, but the reflection effect is positive in terms of temperature in the new rotary kiln solution. When cooled with medium, the chrome-nickel-steel plate oven is more heat-resistant and heat-friendly than a conventional rotary oven.

Therefore, the rotating chromium-nickel-steel heating drum can increase the speed of rotation considerably even when the weight is reduced significantly. By omitting the brittle ceramic liner completely, the limitations due to breakage of the 20 liners, for example by vibration, can be avoided. Drum, ,,,: Thanks to the higher speed of rotation, the material to be heated mixes: ·. the drum is more thermally efficient and the heating is faster. In this way, the heating process becomes more efficient as the particles to be heated become more exposed to the heat rays. The cold raw material is also made to effectively cool the drum due to its high speed. Mixing or cooling - *: * ·: The cooling effect of some of the raw materials can be enhanced, for example, by the use of ridges in the drum in the early stages of the process.

. * 1 ·. 30 The simplest is to make a new heating drum using only medium »> ·. in chrome-nickel-cooled steel without ceramic coating. At the same time, it is possible to increase the heating temperatures in the material or in the combustion generally by, for example, using oxygen-rich feed air. Alternatively, the losses of heating the nitrogen passing through the drum can be reduced by reducing the amount of passive nitrogen passing through.

If the amount of heat passing through the wall of the chrome-nickel-steel drum is too high, the situation can be improved with additional heat insulation. For example, one or more ventilated interlayer layers in the drum or heat resistant ceramic wool can be used. However, the best heat insulator is a vacuum or void that does not conduct heat. By making a drum of two or more layers, a heat insulating vacuum or air space can be created. Cooling of Tyh-10 compartments can be arranged with, for example, water, steam or air flow.

A two or more layer oven made of chromium-nickel steel sheet can be made of corrugated sheets of bent sheet metal. Corrugation can be done by cold or hot rolling or bending. 12 and 13, there is space for air or gas flow on both sides of the zigzag-shaped bending plate. The heat travels along the oblique plate portions of chromium-nickel steel sheets over a long distance, i.e. cooling occurs gradually throughout the heating drum. The additional ceramic layers on top of the chrome-nickel-steel layer improve the thermal insulation and heat resistance of the drum, but at the same time increase the weight. At very high temperatures, it may be necessary to use ceramic layers as an adjunct to air and water cooling in thermal insulation.

• · ,, Effective cooling of the drum is achieved by blowing the drum to the intermediate space. · * *. 25 air mixed with water in liquid form. Its evaporation reduces the heat of the air gap and thus the temperature of the entire drum. The resulting water vapor binds ·, · .; a lot of thermal energy from the drum. The cooled chrome-nickel-steel drum allows · * “: the material has higher combustion temperatures in the furnace.

»# '· ·' 30 Chemical reactions accelerate at high temperatures thanks to the new method, ·, in general. The super-poison switch is destroyed at about 1000 degrees Celsius generally when the residence time in the furnace is long enough, for example 1 ... 2 seconds. For example, 8 113563 scrubber treatment can prevent the entry of harmful combustion gases into the atmosphere. Exhaust gases can be treated with high heat, for example by means of lime sludge. The components of the exhaust gas are then exposed to and react with the reactive calcium oxide. Other chemicals may also be used in the scrubber scrubber to produce the desired reaction or purity. In this way, most of the hazardous waste from the exhaust gases and solid heat-treated masses can be removed. The treatment, disposal, conversion and, in particular, recovery of waste is an important object of the invention.

10 A continuous gas analyzer may be attached to the exhaust gas monitoring, which may also automatically record the quality and acceptability of the exhaust gas. Similarly, solid or liquid heat-treated masses can automatically record the quality of the product and its acceptability, without the need for expensive individual measurements. This is to ensure the environmental safety of the heat treatment operations.

The water vapor generated by cooling, its pressure and energy can be used to preheat the material or, if desired, to generate energy, for example in a steam turbine. If desired, pure hot water vapor can also be discharged into nature if its energy is not used and large pipelines are not built. To maintain the strength of the refractory chrome-nickel steel sheet. : ·. sex at high temperature medium cooling is preferred. The cooling medium may be, for example, the heat-treatable material itself cold before

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heating process. Air, water, or other readily available refrigerant material may also be a cooling medium.

• i> · *. · *: The air used for cooling can be fed to a heat exchanger where energy can be recovered for further processing or other utilization. Large: Hot and swollen volumes of air are a bit tricky to handle. Therefore, cooling air may be directly discharged when heated and possibly containing water vapor.

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The novel invention can accomplish a variety of objectives by designing the heating drum in different ways. The simplest form is a cylindrical tube drum into which the material to be heated is fed from one end (A) and removed from the opposite or same end (B 1). Its burner may produce a flame 5 extending in the direction of the linearly rotating axis 13 of the burner. In this case, the heat source (C) may be on the center axis and the exhaust gas outlet on the same axis at the opposite end of the cylindrical combustion chamber.

The combustion flame can also rotate as a spiral vortex flame, whereupon the fuel and the combustion air are brought into a vortex motion like a cyclone. If fuel and combustion air are fed substantially tangentially to the outer periphery, for example by means of feed wings, an external vortex is formed with its burns. It proceeds helically in the axial direction towards the other end of the vortex space as a free external vortex. Upon contact with the cone or planar end wall, the speed of the free wheel 15 decreases due to surface friction. Larger particles are exposed to the flow layer passing along the surface of the cone or lid and the central removal of heavy particles.

If the vortex reflecting end is conical, the surface flow of the vortex and the larger or heavier particles with it will end up at the tip of the cone and in the outlet B 2. The lighter particles will rotate axially from the cone towards the central tube, positioning the cone at one end of the vortex chamber or combustion chamber causes the fire vortex to • turn inside the cone into a smaller radius of inner radius that • ♦ 25 advances axially to the larger outer vortex; 11. 11.

, ·. The free inner vortex 52 has a smaller radius of rotation and an absolute velocity greater than the larger radius of the outer vortex 51. This results in a large centrifugal force of the inner vortex capable of casting a relatively small ': particle onto the outer periphery. The conical vortex chamber can sort the particles of the heating vortex into two size or light classes. The transfer of the light particles to the tip of the cone and the removal therefrom can be promoted by sucking the tip of the cone from the feed air to remove the particles. The conical vortex separator is thus made to function as a particle separator, in which the separated particles are sorted into two size classes. The separated particles can be separated from the gas by, for example, a multicyclone or a fiber filter. The outermost 5 rotating drum 1 also collects the largest particles on its surface for its own removal B 1.

The result is a total of three different fractions of heated particles from the vortex chamber and drum, which differ in grain size or density. Indirectly, different products with different chemical properties are used for different purposes.

The conical heating chamber is made to act as a cyclone separator vortex chamber. It can distinguish between light and heavy particles with 15 high centrifugal forces and speeds in both vortexes. By changing the taper angle and feed rate, the combustion or heating chamber can also act as a screen for particles of different masses or sizes in different size classes. The rotating burner drum 1 moves at its own pace, independently of the eddies, with its own rotary drive at the desired speed and direction.

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Thus, the invention is not only a heat treatment device for the material, but also a sorting and processing plant for a variety of tasks. Usually warm

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'' *. instead of a single product from a batch process, the new plant provides several different products. This is a great advantage, especially in the recovery of fine materials * · 25 and in the recovery of waste.

«, · · ·, The electric drives and inverters allow the heating drum * ♦ *, ·, speed and direction of rotation to be quickly changed according to the situation. By changing the rotation speed and direction, the material can travel in 30 drums in different ways. The chemical properties of the products may also be "different, not just the difference in grain size. They may also be monitored by» »* '· · *' continuous analyzers as well as the composition of the feed material.

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Transparent windows placed on the walls of the rotating drum allow monitoring and control of the process. In addition to measuring sensors that record video cameras, process monitoring can be used.

5 Chemical effects can be generated in the heat treatment drum by supplying active additives to the furnace. This may be, for example, limestone or calcium carbonate. It decomposes at about 825 to 850 degrees Celsius into calcium oxide and carbon dioxide. Of these, calcium oxide is highly reactive with other substances. In the heat of the furnace, it can melt 10 surfaces of other particles. The furnace temperature can be measured electronically with continuous recording meters.

For example, by making light gravel from silty clay or clayey silt, the largest coarse particles, i.e., silt particles, are exposed to the pellet surface due to the higher melting heat. Figure 17 illustrates this phenomenon. The surface layer of the light gravel granule then contains a large amount of silica crystals, or quartz, which are generally poorly meltable. Calcium oxide can form eutectic mixtures with other melt oxides, whereby the melting point of the poorly melting compound mixture is lowered and melting occurs at relatively low heat. Figure 18 '· ·' 20 illustrates the melting of a glassy bond between the pellet surface and the pellet path by a medium coarse material, for example a bridge having a grain size of 2 to 60 micrometres at high heat to produce a flat expanded product.

The invention can be practiced in many ways e.g. at the same time in the production of light gravel and t. ··· <is a finished raw material for the production of light gravel, in which currently pure t '·'] clay is blended with fuel oil to promote swelling. This pays for ;; t: a lot when expensive fuel is used for some sort of secondary purpose: • '30. The same result can be achieved by the invention so that

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:: Vegetable oil from the food industry is mixed with the ingredient clay. It :: expands pellets just like fuel oil, but at the same time eliminates one waste problem. Due to the high heating temperature of the invention, no harmful fire gases are formed. Similarly, the invention can use the actual waste oil for incineration when the waste gases are clean after the scrubber treatment and the solids are encapsulated at the disposal site or chemically combined with other substances.

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In many cases, sewage sludge is classified as hazardous waste when there is insufficient certainty about treatment. By means of the invention, the result can be controlled by recording devices. The movable plant of the invention provides most of the characteristics of a hazardous waste plant.

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Calcium oxide alone effectively melts the mass at temperatures above 1040 degrees Celsius. Due to the melting effect of calcium oxide and the effect of higher temperatures, the surface of the pellets becomes glassy. When cold, such a lightweight granule has a high compression strength due to its spherical shape and glass envelope. In this way, the invention can produce high-value building material with high heat, combining lightweight grit lightness and high compressive strength. For example, it is easy to produce, for example, new concrete aggregate, replacing traditional stone in concrete with a glass-reinforced artificial stone. It has an expanded porous core that acts as a thermal insulation in concrete, rather than a cold bridge like ordinary stone. This can, for example, remove cold concrete floors and concrete walls from new buildings, »» * * · and make the whole structure lighter.

When calcium carbonate is further added to the furnace of the invention and the temperature is kept high, the surface partially melts into a glass-like shell throughout the furnace pellet mass. It gives mass

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, -. not cold for high strength, a kind of reinforcement. By increasing and controlling the amount and temperature of lime or calcium carbonate, the melting * * #: ;;:: can be increased and the pellet adhesion enhanced. Calcium oxide can be used to: · '30' mix material, or "glue" granules together in a concrete like manner. * ·: To the sex mass. In this way, clay, brick and sand can be made into a furnace according to the invention in a furnace according to the invention, but without expensive cement. The glassy surface layer can be made by fusing silicon compounds to the surface of the 13 113563 bodies as desired. This can be done on products with a glass-tight, water-impermeable surface if desired. If the core of the product mass is porous lightweight material, my floating bowl can be created.

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A dense glass surface can also be generated on the slurry after the furnace treatment, also by post-heating with a separate burner. Inside, the hot mass surface is easy to reheat when the core is already hot after the oven heating. The expanded pellets on the outside of the furnace can be set to the desired shape and size, regardless of the furnace. The required heater may be a smaller movable afterburner, for example a blowing lamp or other burner that prevents the heated material from cooling and curing. If necessary, a melting agent such as calcium oxide may be added to the afterburner. In this way, large lightweight tiles can be formed, for example, as bridges, road foundations, foundations of buildings, floating airports and other structures. It is advantageous to make such large structures directly in their final position and to cool and allow to harden there.

Fine material is available as a raw material for the heating drum 20 according to the invention from virtually anywhere. For example, clay is carried by all currents »*» and rivers carry large quantities. With the suction pump, the material is easily retrieved, for example, from the bottom of the shipping lane. The slurry is then allowed to dry for a few days in the sun. It is advantageous to evaporate the excess water before adding it. While drying in the oven is possible, evaporation of the water requires a large amount of heating energy. Faster drying is achieved by applying a thin layer on the filter in the same style as. * · ·. the paper slurry is dried over a wire in a paper mill, after curing. \ mass is transferred through a refiner to a heating furnace, where the final »'·' .M / material is produced. If necessary, expansion or melting agents or waste material such as iron oxide, calcium carbonate, etc. are added to the furnace.

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»* · '; : product, fly ash, paper deodorant, etc.

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By making the roadbed, for example, by means of the invention, a pulp coated with lighter glass than water is used to create floating road structures, i.e. pontoon bridges. They are valuable in many flood areas where road connections are sometimes interrupted. Similarly, the houses in these areas 5 are made to float in the water in the event of a flood when the heated mass has a volume density below the volume of water. Generally, such pontoon solutions are expensive, but with the present invention, their manufacture becomes affordable.

The porous light expanded product is produced when the raw material material 10 contains finer particles than 0.002 mm, or 2 micrometers, of at least 10 to 20% of the total feedstock input. In this way, a wide variety of fine-grained waste materials can also be recovered and expanded, for example, into thermal insulation or lightening material for many purposes. By melting further 15 glassy shells of coarser mineral particles (grain size greater than 0.1 mm) on the surface, the strength is further improved in the material.

The fused silica strands, like reinforcement, act as cold-resistant parts in the pulp, like reinforcement. The benchmark is the traditional glass bottle, which is difficult to pull. The mass thus has a high tensile strength. An amorphous 20 glassy material is made to break, like glass by impacting it hard, but is not detrimental in many applications. The lightness of the mass and the thermal insulation is a very valuable property which is produced quite advantageously t '[']. from natural materials or waste.

25 Fiberglass fabrics are also glass materials, but they are very durable in most ....: applications. The hot ceramic mass can be counted as hot »». · · ·, Directly from the muffle furnace onto the fiberglass fabric, which gives the material a high tensile strength. The hot material that falls from the oven onto the fiberglass will melt * * '!!. 'Together. The combination resulting from the tensile strength of the glass filaments is extremely strong. The ultra-thin fiberglass strands also withstand the bending '·' to some extent. In this way, large quantities of waste glass fibers for which no use is currently available can be recovered. Naturally, new tensile structures can be made of hot pellets and fiberglass accordingly.

5 The finely divided raw material used in the heat treatment process can be brought to the final application site or to the product manufacturing site in advance for drying and curing. This is the case, for example, in the dredging of harbors and shipping lanes, which as such is generally not exploitable. Various types of urban and ship wastes in bottom sediments require high-heat 10 heat treatment, where pollution is destroyed. Slurry can usually be made into lightweight gravel, which is a valuable lightweight and insulating building material in many urban areas.

According to the invention, a small amount of fine-grained material of less than 2 micrometres in cascade size makes melting easy. Hereby, for example, the sand granules can be "glued" together, for example, as "asphalt road" without bitumen or cement. Likewise, the invention can make the way to the Arctic permafrost without much mass transfer and cost. By expanding the tiles created with additives, a permafrost-protecting thermal insulation on the foundations of houses and roads is formed. In many cases, transporting a small amount of finely divided material is more economical than transferring other material (...) Many wilderness roads, eg in the sand deserts or in northern conditions, are thus economically feasible.

It is also possible to form capsules with glassy quartz or silicate pulp, ..,.: Which can be poisonous, heavy metals and other unwanted materials can be sealed and. · *. tie. Thus, for example, the invention can accomplish the final disposal of waste by chemically binding the waste to other substances.

»I» · * ·] · '30 The glass fiber mat is one of the wastes that is not currently used. By putting it on top of '; / when hot, lightweight gravel pellets are obtained by melting to form a durable composite * · · 'structure for many purposes. Fiberglass gives the structure an important tensile strength.

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By means of the invention, the material to be treated at high temperature can be made cold as a solid rocky product or as a porous cold as heat insulating light material or as an intermediate thereof by controlling the temperature in the oven. Most mineral materials can be used as raw materials in the pulp, for example clay, ash, silt, sand, mining waste, sewage sludge, industrial waste, waste soil, contaminated soil, fly ash, moraine, etc. The finely divided materials thanks to its heat resistance.

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The expanded heating product is made from natural clay at about 1150 degrees Celsius in a conventional heating drum. The particles then lose their crystalline water and swell as the gases discharge into the mass. Ordinary clay expands in this heat without additives in a traditional oven. In the new heating drum according to the invention, even a much lower temperature is sufficient to achieve swelling, with the right mixture of materials at a wall temperature of up to 600 ... 800 degrees. If swelling is not sufficient, it can be promoted by adding readily decomposable oxides to the raw material. Such is, for example, iron oxide, which is a waste of the metal industry. 20 characters. It is better known as rust. Iron oxide loses its oxygen atom, an oxygen gas that expands the mass. The remaining metallic iron binds · · · to the mineral material, such as clay. Even a small amount of iron oxide

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. ,,,: The addition causes almost all masses to swell in the oven. Also in other, · · *. similar phenomena occur in the oxides and the mass expands.

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High surface strength is achieved by sintering or melting the surface at a high temperature of about 1000 to 2000 degrees Celsius. In the new In a furnace solution, sintering can occur at slightly lower temperatures.

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In order to prevent too rapid curing, it is preferable that the * · "· oven according to the invention is movable and the product is lowered to its final position immediately upon leaving the furnace, for example, when making a road or field. after which, the material cools rapidly and hardens, therefore the molding time must be kept short.

For example, a grate cooler 5 may be used to recover heat from the product. Too large pieces of product created in the oven must be broken into smaller pieces by dropping large pieces from high up into the cutting brush on the bottom of the oven while the oven is running. Figure 20 is a cross-sectional view of the refractory lifting rods disposed in the furnace. They lift too large pieces as the drum rotates up and drop them in the oven from top to bottom and break the 10 when striking the nucleus floor.

Thereafter, the power of the furnace can be increased by means of rod lifts without much fear of the so-called cam ring generated by the furnace. In it, the lightweight pellets melt from their surface and stick together even in large bundles 15, disrupting the operation of a traditional oven.

The product pellets can be easily cooled, for example by means of an air cooler, by blowing a large amount of air into the pellet mass. The released hot air or steam can be utilized, for example, in preheating the material. The heat exchanger 20 can be used to heat some of the hot gas used

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for other use. Used gas can be replaced with new gas, which can ... act as a new refrigerant. Exhaust gas cooled by heat exchanger * ».I" · goes into a much smaller space than hot exhaust gas.

»·, · · ·. with smaller exhaust pipes.

»· 25. ,,,: Heat conducts efficiently longitudinally along the drum structure.

. · * *. For example, in a chrome-nickel-steel cement clinker kiln, I *. '. manually the radiant heat produces about 1500 ° C in the cement furnace mass • * »». I'm generally. Under such extreme heat, the minerals melt to form Portland * · 30 cement clinker. The heat-treated cold raw material may be '; (': Direct the treatment drum from one end to the medium to cool the hot head' 'too much heat.

18 113563 The cooling medium may be, for example, material to be heated as cold, water, air or cold product powder. Because of the good thermal conductivity of chromium-nickel steel, the temperature differences in the drum tend to equalize quickly. The cooling medium is then cold raw material. It helps keep the temperature of the chromium-nickel-5 steel plate sufficiently low so that the strength of the drum material remains sufficiently high.

The maximum radiant heat performs the desired heating function in the drum, but at the same time preheats the raw material by heat conduction along the drum. It is then advantageous to make the drum a uniform heat-conducting metal structure to promote heat conduction. The hottest point of radiant heat in the drum will be cooled while the cold raw material will be preheated elsewhere in the drum. The heat can only be transferred by conduction without any actual losses. The chromium-nickel-steel plate can withstand these required temperatures and temperature differences, especially when cooled. The chrome-nickel-steel plate is a stainless material that prevents corrosion problems and enables chemically demanding applications.

The conduction of heat in the longitudinal direction of the heater drum can be increased by longitudinal chromium-nickel steel ridges which, during rotation, simultaneously act as lifts and throwers of the material to be heated, thereby removing the material particles from the surface of the drum to heat radiation.

I ·, - · -, The manufacture of artificial stones, cement and light gravel are typical mass products 25, which require a lot of energy in the heat treatment. Remediation of contaminated land and waste disposal are also typical of heat treatment. * ·. items that require high temperature and chemical resistance. Industrial. In the processes of the mouth, the heat treatment can re-obtain the materials t * * * ;; ' for use. Such a use is, for example, the honey I '30 sauna used by the cellulose industry. Combining substances into new compounds or chemically dividing the substances into various components also requires heat treatment, often in a high temperature state. Potential fields of application are most of today's industries.

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The refractory chromium-nickel steel sheet used as the raw material of the invention is made of a refractory metal alloy containing generally 16 to 28% chromium and 8 to 24% nickel, sometimes up to 30 to 70% nickel. In addition, the alloy has a low carbon content of generally less than 0.2%, a low silicon content of less than 2.5%, a low man-5 gane content of less than 2.5% and iron in addition to small amounts of other substances such as molybdenum, vanadium, copper, cobalt . The metal raw material is weldable to facilitate manufacturing.

The following figures are intended to be illustrative only and to illustrate the operation of the invention.

Figure 1 shows a cross-sectional piece of a conventional steel heating drum 16 lined with ceramic wedge-shaped bricks 17 leaning against one another. The purpose of the bricks is to protect the steel drum from high radiation heat. 15 The structure is heavy and laborious to build. Due to temperature changes there is a small gap 15 between the bricks.

Fig. 2 is a longitudinal section through a fluid-cooled cylindrical heater drum 1 in accordance with the invention. In this case, the radius of the largest chromium-nickel steel drum exiting from the burner 6 is the radius of 7 · ···. in this area. When high radiant heat is encountered in chromium-nickel steel .... the heat of the drum 1 made is partially reflected back to the drum and the heating material 11. Part of the radiant heat is passed through the chromium-nickel steel layer according to the principle of arrows 8 in Figure 2. Maximum effect on the drum: ··: The radiant heat is roughly in the area indicated by the arrows 8 where the heat is emitted · “; dissipated through the drum and the longitudinal direction according to the arrow 10 of the drum per cold head, wherein the heat-face finish drum heated • »· · · · ·.. The cold-heated material 11 may serve as the main cooling medium of the entire drum 1 from the feed ramp 12 to the drum. A fixed thermal shield 2 may be positioned above and adjacent to the feed ramp 12 to conserve the heat of the furnace. Only 20 113563 small openings at bottom A and B1 are left for material inlet and outlet. at the hottest point of the drum due to heat partly in the direction of the arrow 9. Outside the chrome-nickel-steel cylinder, another cylindrical metal drum 4 made of lightweight material, e.g. aluminum, can be placed. The space 3 between them may be airspace 5 which does not conduct heat. The gap can also be filled with ceramic wool, but it adds heat-conducting medium. Wool blocks air movements, but they can be blocked anyway. Figure 2 also shows a post-heater 37 of the heated material, which heats the heat-treated material to improve the ductility.

10 In this case, the thermal insulation has been increased by the thermal insulation space 3, which is an empty space in the drum. A cooling jet of air may be introduced there, or a jet of water may be injected into the air which, when evaporated, will bind the heat and cool the drum 1. The need, quality, thickness and length of the other insulation will be determined on a case-by-case basis. Usually, for example, 5 to 30 cm thick ceramic wool, which is ventilated with normal air, or which is held under reduced pressure by means of a vacuum pump, may be used as the thermal insulation of the drum to improve the thermal insulation capacity. A lightweight protective layer, for example, of aluminum plate, can be placed on the thermal insulation.

20.,.,: The chrome-nickel-steel drum may be cylindrical. The drum 1 may be as shown in Figure 2. ': Chrome-nickel steel over the entire length of the heating drum or expensive. '* ·. the part of the chromium-nickel steel drum can only be in the region of the hottest radiant heat. The cooler portions of the heating drum can be made to save expensive chromium-nickel steel from other metals, for example plain steel. The connection between the drum cylindrical chrome-nickel-steel part and the cylindrical extension •: * ·: can be accomplished, for example, by welding or by a heat-conducting flange connection. An expensive drum part made of chrome-nickel steel on either side, or: only one side can be made of another metal, eg plain steel. · * ·. 30 made cylindrical drum extension. The incoming heatable feedstock 11 is a cool medium material and flows, for example, along a ramp 12 in a drum. / wood at one end, cooling the entire drum structure with its mass.

The material to be heated advances in the drum towards one end having the end wall 2, if necessary, or no end wall at all. After heating, the heat-treated material leaves, for example, one end of the drum over the edge. The heat-treated material exiting the drum is still hot, so it is advantageous to recover the heat energy contained therein, for example by means of a heat exchanger in a known manner. The thermal energy obtained can be used, for example, to preheat the combustion air, or it can be used to preheat the material to be heated or to generate electrical energy.

The burner 6 generally does not rotate with the drum, but is attached to the outside of the drum 10. The flame exiting the burner may extend linearly in the axial direction of the combustion chamber or may be made to rotate in a spiral like cyclone, according to the principle of Figure 11.

Figure 3 is a cross-sectional view taken along line I-1 in Figure 2. Outside the void space of the thermal insulation 3 or 15, a protective layer 4 in Figure 2 may also be applied if necessary. The structure shown in the figure is thick but light if ceramic wool is used as the insulation 3. The empty space in the drum is an effective thermal insulation. Therefore, the rotation speed of the drum can be increased to the desired level.

Fig. 4 shows a cross-sectional view of a chromium-nickel-steel drum according to the invention. black with wear-resistant ridges 23 to remove material: from drum 1 surface. The ridge throws the material into the direction of the arrows 24, for example, especially when the drum is rotating at high speed. The ridge 23 may be •; · ·: hollow as shown or may include longitudinal heat conductors 25 of drum, e.g. chrome-nickel steel. can be of different sizes, thereby changing the direction of rotation of the drum by changing the thrust.

Fig. 5 is a longitudinal sectional view of a chromium-nickel-steel drum in accordance with the invention in very high temperature ranges. The area of maximum heat stress: the area of the chromium-nickel steel drum 1 may be protected by ceramic or other means. · · ·. with a protective layer 25. This layer can be applied, for example, by spraying it on a high heat resistant reinforcing mesh.

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Fig. 8 shows a longitudinal section through a heating drum according to the invention provided with a cone 28, which can at the same time function as a screen and separator of heat-treated material. The feed air and fuel 31, guided by the blades 30, enter a substantially tangentially cylindrical vortex space, first forming an outer vortex. The cone-shaped low-radius inner vortex contains the lightest particles and gases that tend to enter the central conduit 21. Due to the hot flow, the central conduit 21 must be effectively cooled or made of ceramic material or expensive special metal. The feed of the raw material cools the cone 28 from the outside if the raw material is cold.

10 In this case, the cone is secured to the heating drum by flow pipes. The flow tubes 26 allow cooling air or water to pass between the drum and the cone 28. The drum 1 rotates, the feed media guides 33 rotate with the drum and the drum ahtavat material in the direction of the arrow. The cone 28 is provided with an air gap to isolate heat from the metal in the smallest and hottest of the bat clubs. The thin tubes 26 conduct the cooling from the drum to the cone. The arrow 18 represents the inlet of the cooling medium, for example air or water, and the arrow 19 the outlet. The arrow 31 indicates the general direction of flow of the feed vortex in the axial direction. The baffle plate 33 may, during rotation, conduct the heated feed material 32 into the cylindrical combustion or vortex drum 20 wood 1. The layer 20 may be a light pipe of a coolant, e.g. water or air, flow pipe around the drum 1. Using many. ·: ·. a jacket layer 20 and a cooling medium such as air flowing therebetween; and / or possibly a water jet which evaporates to water vapor is obtained by a jacket; · · J layers to gradually cool down so that the temperature of the outer layer is: * '*: 25 even below 100 ° C. The cooling of the drum 1 and the inner surface reflecting the heat rays mirrors the heating and cooling; · ·: Such that the temperature difference between the hottest part of the heater drum and the heater • space it delimits is above 300 ° C, preferably above 400 ° C. Heating mode:. ·. the temperature of the hottest spot is typically above 1000 ° C and the metal • »*». '. The temperature of the hottest points of the 30 drum is below 700 ° C, preferably. from about 550 ° C to about 650 ° C.

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Fig. 9 is a cross-sectional view taken along line IV-IV in Fig. 8. The feed blades 30 may be adjusted to a desired steering angle to provide a desired vortex in the drum. The pitch may be adjustable according to material or capacity. The fuel is ignited by continuous spark ignition immediately after 5 wings 30. The central tube 21 may be coated or cooled, for example with water, to withstand high heat. An intermediate space may be provided against the drum 1 to avoid heating the drum. The drum 1 can be insulated with air spaces formed on different sides of zigzag-shaped sheets.

Fig. 10 shows a cross-section along the line V-V in Fig. 8. In the aperture 34 at the end of the cone, a free vortex collects fine material from cone 28. The fine material can be subjected to further processing, for example a multicyclone or fabric filter

Figure 11 illustrates the principle of a double vortex vortex chamber. The tangential feed 53 first forms a larger radius outer vortex 51. Due to the friction caused by the cone, the vortex ends and turns into a small radius inner vortex 52 directed towards the center tube. The most finely divided material exits via B3 after a large centrifugal treatment.

20 A slightly coarser fraction is removed from the tip of the cone through B2.

. Fig. 12 shows the heat insulation obtained by bending the chromium-nickel steel sheet 35 inside the drum 20 to form a zigzag for voids 18 • · · j and 19 for the passage of refrigerant. The bent plate 35 is welded to the drum 20 25 only for each piece. at one point, so heat movements are possible.

Figure 13 shows a two - layer zigzag sheet structure, whereby a large amount of heat - insulating voids are • formed and the heat conduction distance in the metal structure is:. long. This makes the heat flow in the structure more difficult. The voids 18 and 19 may be; * '·. 30 spray water in liquid form which, when evaporated, traps heat from the drum,. or cold air to cool the drum 1. Strength of the structure can be improved by the intermediate drum 36.

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Fig. 14 is a side elevational view of a wheeled heater 57 according to the invention for applying hot material directly to a construction site, for example as a road base 44. The base may be made strong or light with additives as required. The ductility of the pulp 44 can be improved 5 as needed by a small additional heater, for example an auxiliary heater of the blowing lamp type (not shown). Part 41 denotes a hopper for the material to be heated, and part 42 denotes a multicyclone, a fabric filter, or a fine material collection container.

Figure 15 is a side view of a movable device according to the invention parked on a waterfront. If desired, the material may be lowered into water, after heating and cooling, for example as a pontoon, bridge or floating platform 45, which may be, for example, part of a large floating airport. The material to be heated may be preheated to promote expansion and improve buoyancy in a separate drum 55.

Fig. 16 shows the cooling air guiding between the two drums 1 and 20 through the channels 18 and 19. The air passage can be designed so that the system functions to cool the drum like a heat exchanger, thus also providing> '*. 20 hot air for desired application. The purpose of the baffles 35 is to increase •: *. I provide heat conduction distance by means of sloping structure.

Figure 17 illustrates the principle of: *: placement of furnace pellet pulp particles in heating foam. Larger size particles 39 do not melt easily, so they end up on the pellet surface. In the center of the granule remains a porous and light material 40 of finer material. The outermost part is a vitreous layer 38 formed by sintering, the formation and melting of which is promoted by calcium oxide in the furnace.

Fig. 18 shows high temperature melted and glued pellets according to Fig. 17. The body can have high strength due to its glassy material, although its weight is moderately low.

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Figure 19 is a sectional view of a road structure made in accordance with the invention, wherein a stronger surface layer 47 and asphalt 46 are applied over porous and lightweight lower layers 48.

Fig. 20 is a cross-sectional view of a portion of a heating drum according to the invention in which high temperature-resistant lifting rods 49 at different distances from the heating drum 1 accumulated in the furnace fused pellet bundles 50 can lift differently sized bundles of drum 50 against the drum. The pellet bundle drops from the top to the bottom of the oven wheel and breaks into pieces when it hits a hard surface in the oven. In this way, the furnace can continue to function normally even though the furnace temperature has been increased in accordance with the invention and the risk of pellet bundles is increased. The rods are fastened to their rings at their ends.

Figure 21 shows a water-floating raft or pier constructed in accordance with the invention in which the expanded material 48 keeps the raft floating due to its lightness. Robust material 47 withstands traffic loads.

Figure 22 shows a floating structure raised from the water to the pillars 56, which permits ·. 20 water transport passage under the structure.

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Claims (20)

26 113563 A patent is claimed A method for heating a material to a high temperature in a heating drum, which is a hollow elongated tubular heating drum rotating about a horizontal or inclined axis, having at one end a material to be heated (A) and a heat treated material removal at one or more ends and a heat source (C) located at an end of the drum opposite to the feed end of the material to be heated, whereby the material to be heated is gradually heated as it moves from the material feed end to the heat source, characterized by a refractory chromium cooled from the outside with the medium and the material to be heated on the inside as it slides or rolls along the metal surface of the heater drum while at the same time a tall heating drum is used to equalize temperatures, raise temperatures and conduct heat, and that heating the material to a high temperature in the heating drum is enhanced by the reflection of the heat rays on the chromium-nickel steel plate. 20 Method according to claim 1, characterized in that ·. balance the heating and cooling of the drum so that the heat · ·. the hottest part of the drum and its limited heating space ...: the temperature difference is above 300 ° C, preferably above 400 ° C. 25 «· Method according to Claim 1, characterized in that the heating of the material to a high temperature in the heating drum is enhanced by combustion in an oxygen-enriched air or by an electric heater. • · •: ·; 30 Method according to one of Claims 1 to 3, characterized in that, * · «. that the fuel is injected into the heating drum from behind the blades (30) providing an air vortex and ignited immediately after the blades (30), whereby a combustible vortex is formed in the heating drum. Method according to one of Claims 1 to 4, characterized in that the heating of the material to a high temperature takes place in a vortex separator of a burning vortex to separate or divide the heat-treated material into different classes. A method according to any one of claims 1 to 5, characterized in that the drum is thermally insulated or cooled by a drum wall formed by two or more layers of plates between which there is a gap for a cooling medium such as water jet, water vapor and / or air. Method according to one of Claims 1 to 6, characterized in that the metal heating drum acts as a heat transfer means in the longitudinal direction of the drum. Method according to one of Claims 1 to 7, characterized in that the heater drum, which is lighter than a steel brick lined drum, is moved by wheels during heating or between heating cycles. . ···. A method according to any one of claims 1 to 8, characterized in that the temperature of the hottest part of the heating space is above 1000 ° C and the metal is · * '. The temperature of the hottest part of the heater drum is below 700 ° C, preferably at about 550-650 ° C. I · i • · · • I Method according to one of Claims 1 to 9, characterized in that the calcium oxide is added as a melt to the hot heating drum. 30 I t | 113563 Method according to one of Claims 1 to 10, characterized in that the oil-contaminated soil is used as a raw material or energy source for the production of light gravel. Apparatus for heating material to a high temperature in a heating drum, which is a hollow elongated tubular heating drum rotating about a horizontal or inclined axis, having at one end a material to be heated (A) and a heat treated material removal at one or more ends and A source (C) of -10 m at the end of the drum opposite the feed end of the material to be heated, whereby the material to be heated is gradually heated as it moves from the feed end to the heat source, characterized in that the rotating heater drum nickel-steel 15 or chromium-nickel-steel alloy coated on the inside, whereby the heating space-limiting metal heating drum acts to equalize temperatures, increase temperatures and conduct heat characterized in that the heating drum is arranged to be cooled by an external medium and an interior material by means of the material to be heated in the drum, and that the heating of the material 20 to the high temperature racket in the zone. : '"; 25 Device according to Claim 12, characterized in that the wall of the drum formed by the cooled chromium-nickel steel layer is thermally insulated from the outside of the drum. • · ». ··. Device according to Claim 12 or 13, characterized in that the thermal insulation or cooling of the drum 30 · 30 · · · · is carried out by two or more layers of plates between which there is a gap of a cooling medium such as a water jet. . : for water vapor and / or air. > * I • I 113563 Device according to one of Claims 12 to 14, characterized in that the heating of the material to high temperature is followed by a process in the vortex separator of the combustible vortex to separate or divide the heat-treated material into different classes. 5 Device according to one of Claims 12 to 15, characterized in that the heating drum acts as a heat transfer means in the longitudinal direction of the drum. Apparatus according to any one of claims 12 to 16, characterized in that the heating drum, lighter than steel bricks lined with steel structures, is made movable by wheels. Device according to one of Claims 12 to 17, characterized in that the main material of the drum is another metal coated with a chromium-nickel-steel alloy. Device according to one of Claims 12 to 18, characterized in that the device is made so light that the rotation speed of the drum can be increased to a value of 10-100 rpm. 20 '. Use of a method according to any one of claims 1 to 11 or a device according to claims 12 to 19, characterized in that chromium. '· ·. nickel-steel drum is used for any of the following: ....: for the production of light gravel, waste recovery, lime kiln or blend; ···. 25 remediation of contaminated land, destruction or encapsulation of substances hazardous to the environment. • ·> • · · • »•» * · * (ti • i »» »» l t t * * »30 113563