DE19909043A1 - Method and installation for producing brickyard product - Google Patents

Abstract

Product moldings are made of a mixture which besides heat treated recent aqueous sediments contains no further constituents consisting of aqueous sediments or clay. The heat treatment of the recent aqueous sediments consists of their calcination. The required moisture of the mixture is obtained by addition of water. The heat treatment unit (12) and the firing kiln (14) are connected by two gas lines (26, 28) leading into kiln zones respectively with low and high temperatures. Gas flow rates in these two lines are regulatable.

Description

The invention relates to a method for producing goat Leye products from recent water sediments with a high content of water and organic substances, from which a heat-treated water sediment and moisture holding mixture of moldings and these moldings then be burned. The invention further relates a system for carrying out the process or for manufacturing Development of brick products from recent water sediments with a high content of water and organic substances, comprising a heat treatment device for heat treatment of the water sediments and a kiln for burning the Moldings passing through at least one gas pipe with the heat treatment device is connected.

Usually used for the production of brick products predominantly mine clay used in prehistoric times when freshwater sediments were deposited. However, these stand Tones are not available in unlimited quantities, especially since they are straight in the Federal Republic of Germany or other states with a high population density are increasingly built up and therefore lost for sound extraction. To protect the na natural clay deposits it is therefore sensible to look for substitute material fen to look for, which is also used to make goat Suitable for leek products and inexpensively and in large quantities are available.

These criteria are met by recent sediments that for example in estuaries, harbor basins, reservoirs and the like due to a slowdown in water flow settle and have to be dredged regularly to reach the Example of sufficient water depth for shipping to care. So far, these dredged sediments become mostly deposited in sinks because they are often in considerable quantities scale with heavy metals, acids, organic coals  hydrogen compounds or other pollutants and are therefore unsuitable for other purposes. However, that too Landfilling of this dredged material is not insignificant environmental pollution stungen result, z. B. by outgassing methane, Staubero sion and leachate, and therefore often affects the population resistance in the vicinity of the landfill.

It has already been suggested several times that the result Use dredged material for the production of brickwork the. However, it also has several properties, one of which Barriers in the way. First, its water content is with up to 80% by weight very high and with it also the shrinkage when Drying and burning and the necessary to remove the water energy requirements. Second, the dredged material contains larger ones Amounts of combustible organic substances that a high porosity and therefore low strength of the out result in brandes. Third, the dredged material mostly shows an unfavorable grain size distribution of about 20 microns to 60 microns because it is often from a mining site comes, for example, from a port in which very similar moderate flow conditions prevail, so that there dumped sediment is very homogeneous. That means it is almost completely in a very narrow section of the sieve curve and may even have a tendency to grain. Just like in the production of concrete, however, also in the Blocking the grain distribution of the aggregates within a larger area can be distributed to optimal strength to achieve properties.

For the aforementioned reasons, brick products were made So far mostly made from mixtures in which the An part of harbor silt or other recent sediments was at most 50%, as for example in DE 41 02 159 C2 disclosed. With this approach, however, we which can still protect the clay deposits to a greater extent the large amounts of dredged material in this way be recycled or recycled.  

In contrast, the applicant himself in DE 39 05 143 A1 and proposed in DE 39 26 649 A1 two methods with which are essentially made entirely of brick products recent water sediments with a high water content and organic components. From the ge DE 39 26 649 A1 describes a Ver drive, in which part of the sediments through heat treatment at temperatures up to 330 ° C a heat-treated pre product is produced, in which the heat-treated Pre-product, if necessary after crushing to the desired one Granulometry with another, untreated part of the Sedi elements is mixed in such a mixing ratio that a mixture with a moisture content of 4 to 12% by weight arises, and this mixture then forms processed and at ceramic firing temperatures is burned.

In the course of further investigations, however, the applicant has found that the known method has some drawbacks having. On the one hand, they contain plasticizers added fresh sediments still organic components, so that the porosity of the fired brick products is greater than that of conventional pit clay Is brick products. On the other hand, they are fresh Sediments containing pollutants, such as mercury or acids, expelled in the kiln, which is a larger apparatus there Effort to treat the escaping gases is required makes. There is also another major disadvantage of the known method in that the added fresh Sedi ment change the grain size distribution in the preliminary product, so that the grain sizes of the added fresh sediment would have to be taken into account to obtain an optimal grain size distribution in the kiln. However, this encounters difficulties because of any dredged material has different grain size distributions.

Proceeding from this, the invention is based on the object to eliminate the disadvantages mentioned.

This task is fiction, with respect to the method moderately solved in that the moldings from a mixture be placed next to the heat-treated water sedi no more from water sediments or pit clay existing components that contains the water sediments calcined during heat treatment, d. H. be half-burned and that the moisture by adding water to the kalzi water sediments into the mixture.

The solution according to the invention makes it possible to produce brick products To produce exclusively from dredged material, the organic be components, mercury and acids even before burning to remove completely, and to burn the granulometry of the masses exactly to a desired optimal value to deliver.

A preferred embodiment of the invention provides that the Calcining the water sediments after a previous one Dewatering, wet processing and drying takes place and at Temperatures between 300 and 700 ° C is carried out. Of the One reason for this is that at higher temperatures the ceramic activity of the sediments is lost means that they become a chamotte that has neither water absorbs is still formable when moistened. At deep On the other hand, the temperature remains too high organic constituents and thus in particular the porosity of the brick products is not optimally reduced become.

According to a further preferred embodiment of the invention the water sediments after a previous drainage Cleaning and wet processing in a single process step dried and calcined. This summary of drying and calcination reduces the cost of the process and before  all the equipment necessary to carry out the process. A slightly higher exhaust gas flow arises, which is relative has a high water content. However, this interferes with the process of Procedural not. The water in the exhaust gas is overheated Steam, that is contained in gaseous form and can therefore by a Ka min can be easily removed. Another advantage over conventional systems is that in this Ausfü the number of emission sources drastically reduced becomes. There are three to four in the usual methods Emission sources, namely according to the process steps Drying, brooding, calcining, burning. These are invented appropriately combined into one. Here is the resulting exhaust gas quantity is less than the sum of three to four Exhaust gases from individual sources. In addition, the apparatus Effort significantly simplified.

The pre-dewatering preceding the production process takes place partly by storing fresh water sediments, partly by mechanical processes such as centrifugation, filter presses u. a., z. B. in the Hamburg meta process to the moisture reduce the sediment to 40 to 60% by weight, ge followed, if necessary, by wet processing for removal of foreign bodies and coarse-grained components, as well as one Drying step at temperatures around or below 100 degrees, at which the moisture in the water sediments by supply evaporated from heat.

The dried water sediments are then, for example cal. in a rotary kiln or another calciner Decorated, with agglomeration or caking larger particles or clumps form during calcination be crushed again in the calcining furnace after the discharge, until a homogeneous intermediate product with grain as the end product sizes between 20 µm and 1000 µm, which is the desired one Grain size distribution, preferably in the form of a fuller curve having.  

If necessary, an additional one before the calcination Classification of the water sediments carried out by sieving be according to the sieve curve, which depends on the Her Place of origin of the sediments can be different, the Bedin to be determined when calcining. Depending on this strainer The curve can also be set according to the conditions which the water sediments ge in a single operation dries and calcines. Even after the calcination if necessary, a classification can be provided if the grain size distribution of the calcined intermediate not that reflects the desired distribution pattern.

Another preferred embodiment of the invention provides that the water sediments depending on the type of goat desired Leier products at different temperatures and / or un calcined for different lengths of time, resulting in both Shrinkage when burning as well as the porosity, the space importance and the mechanical strength of the finished brick eggs Have certificates changed in a targeted manner. Like attempts by the applicant have resulted, the calcination temperature is preferably between 300 and 400 ° C when the calcined water sedi elements for the production of backing bricks, partition walls and Soundproofing material and other bricks with good warmth insulation and limited strength should be used, while when used for facing bricks between 400 and 500 ° C and preferred for clinker with high strength is above 500 ° C. This means that only through changes change of the calcination conditions from one and the same Ge Water sediment brick egg products with different egg have properties manufactured, all of which by DIN 105 required properties.

Instead of the whole, for one type of brickwork calcine sediment used at a temperature to to condition its properties as needed also the ability to add different parts of the sediment calcine different temperatures by at  for example, a sediment layer from different sides is heated to different degrees to a desired To generate temperature gradients in the layer. As a product then creates a brick that has the above properties owns shares and is versatile, but for the only medium quality properties in each application Fulfills.

Known per se during or after the calcination sets for changing the color, surface texture, sintering properties, frost resistance, efflorescence properties and strength of the brick products the sediments to be calcined or the calcined intermediate product are added.

Since the calcined intermediate is without additional Do not process moisture into combustible moldings can, according to the invention, water is added until Moisture content between 4 and 12 wt .-% and preferably is about 7% by weight. Then it is white without addition other plasticizers, d. H. without adding water not calcined water sediments or pit clay mixed into a homogeneous mass, which then forms with the desired shape is processed, for example large-format bricks or perforated bricks that deal with the be did not read known processes from dredged material alone sen.

After shaping, the finished moldings are in one Kiln burned, the furnace gases according to another be preferred embodiment of the invention for heating the water sediments are used during the calcination. A see particularly preferred embodiment of the invention before, used for heating and thereby with carbonization gases enriched furnace gases then back into the kiln the calorific value of the smoldering gases for burning the goat to exploit egg products. Finally, it is also possible  the used for heating and thereby with carbonization gases enriched furnace gases immediately to heat the calciner use the oven.

In addition, the temperature of the furnace gases can also be controlled and thus the calcining temperature in a simple manner change if the furnace gases according to another advantageous Embodiment of the invention in at least two places with un different gas temperatures are withdrawn from the kiln and their temperature by changing the mixing ratio ses on those required for calcining the water sediments Value is set. The removal is preferably carried out on sol areas where the furnace gases contain less than 5% oxygen included, so that after their enrichment with the at Calcining Schwelga emerging from the water sediments cannot form an explosive mixture.

According to a further preferred embodiment of the invention has been found that the mixture to reduce the Melting point a sintering agent can be added. On this way it is achieved that from the water sediments fired brick products at comparatively low Temperatures can be sintered.

According to a further preferred embodiment of the invention combustion products are added to the mixture. These can from boiler ash and / or filter dust and / or slag stand in the case of burns, especially in large-scale Plants arise. As particularly favorable for reducing the Sintering temperature combustion products have emerged provides, at least partially a waste incineration plant have been removed. These combustion products have become proven in experiments as a particularly favorable flux, with its help the sintering temperature of the water sediments can be greatly reduced.  

According to a further preferred embodiment of the invention these combustion products are at least 400 ° C ther mixed pretreated. In this pretreatment, the Combustion products expelled chlorine compounds and before maintains that when the temperature falls below 350 ° C sublimate.

According to a further preferred embodiment of the invention the combustion products are the freshly delivered Ge water sediments mixed and together with these kalzi kidney. In this way it is achieved that at the emergency anyway agile calcination of the water sediments the chlorine compounds gen from the combustion products and as Exhaust gases can be used in an exhaust system.

According to a further preferred embodiment of the invention the chlorine-containing exhaust gas becomes a calcareous absorbent an exhaust gas cleaning system. The one after this Reini Exhaust gases can be generated via a chimney in the system be removed.

With regard to the system for performing the invention The method is proposed according to the invention that the heat treatment device and the kiln by two at a distance gas lines leading from one another into the kiln are, one of which is in a high temperature area preferably near the center of the furnace, and one in an area lower temperatures, preferably near an oven of the flows, and that the flow rates in the gas pipes are adjustable to control the temperature of the heat treatment device supplied hot furnace gases and thus the properties of the calcined intermediate lichen.

The heat treatment device may be a rotary kiln Include a shaft furnace or another calcining furnace in which  the sediments reach temperatures between 300 and 700 ° C heat and let it calcine.

Another preferred embodiment of the invention provides that the heat treatment device by another gas channel is connected to a combustion chamber in which the when heating carbonization gases expelled from the sediments can be burned to take advantage of their calorific value. The Combustion chamber can be in or above the preferably as Ge genlauftunnelofen trained furnace, so that the hot combustion gases from the combustion chamber through openings directly into a cooking zone of the distillery can be initiated to heat the fired material.

Alternatively, the combustion chamber can be near a Drying oven can be arranged in which the sediments before the Calcination can be dried with dehydration, or in close to the calciner or for drying and calcining suitable oven.

In a further preferred embodiment of the invention the calciner is on immediately above the kiln ordered so that very short distances for the hot gases hen. According to another, the calcining furnace is ahead preferred embodiment of the invention as a tunnel furnace forms. This can preferably consist of two parallel to each other running tunnels, one of which is above the another runs. The two tunnels are going in the opposite direction run through the material to be calcined. The Implementation from the upper to the lower tunnel with the help of a pa ternosters.

According to a further preferred embodiment of the invention is a metering device for the measured introduction of Combustion products are provided in the water sediments. With With the help of this dosing device, the most accurate possible Do Incineration of combustion products in the water sediments  be made. In addition, with the help of this Thursday siereinrichtung also an exact adjustment of the dosing Combustion products to the identified ingredients be made, which are contained in the water sediments are.

According to a further preferred embodiment of the invention is the metering device to a quantitative ratio of the water sediments for combustion products from 3% to 20% adjustable. Such a wide range of doses Quantities are necessary to get into the respective sediments amount of combustion products to be introduced to the fixed be able to adjust the constituents of the sediments.

According to a further preferred embodiment of the invention is the metering device in the conveying direction of the water sedi elements in front of the drying oven. That way the combustion products at the same time as the water sediments warmed so that they could be used in a favorable way with the Allow water sediments to mix.

According to a further preferred embodiment of the invention is an exhaust gas purification system for the removal of chlorine compounds gene provided. These can occur in particular if the combustion products, d. H. Kettle ash, filter dust and / or slag from waste incineration plants. Straight these combustion products are suitable for improving the Sintering properties of the water sediments very good. You own zen the disadvantage, however, that chlorine compounds ent in them are holding. These sublimate at temperatures below 350 ° C and form a white / gray dust. This ever occurs according to the content of chlorine compounds in comparatively large Quantities so that fans, pipes, Burner and many other parts of the system are clogged or on become inoperative. In addition, there is Danger of falling below a temperature of 100 ° C  ent with the abundant water vapor hydrochloric acid stands, which can cause considerable damage.

For this reason, they are from a waste incineration plant Combustion products from a thermal pretreatment subjected to treatment at temperatures around or above 400 ° C takes place. The chlorine is at these temperatures compounds in a vaporous state and can be common sam with the steam and Exhaust gas components are transported safely through the system, so that the combustion and drying already described operations can be carried out. But before the tempera is below the exhaust gases in the Exhaust gas cleaning system through a calcareous absorbent Chlorine compounds withdrawn.

Although such an exhaust gas cleaning system is only shown in FIG. 2 for a system in which the heating and calcining takes place in one process step, a corresponding exhaust gas cleaning system can also be provided in the brick plant shown in FIG. 1, in which the heating up of the Water sediments and their calcining takes place in two different furnaces.

In the following the invention with reference to one in the drawing illustrated embodiment explained in more detail. Show it:

Fig. 1 is a schematic representation of a system according to the invention with separate heat treatment devices for calcining and drying water bodies and a counterflow tunnel furnace for firing brick products from moldings which have been produced with the addition of water from the calcined water sediments;

Fig. 2 is a schematic representation of a system according to the invention with a heat treatment device which is suitable both for calcining and for drying water sediments, and a counter-tunnel furnace for firing brick products from moldings;

Fig. 3 is a schematic representation of another plant that is suitable for both calcining and drying water;

Fig. 4 is a graph showing a temperature curve in the two-channel drying and calcining;

Figure 5 is a cross-sectional view of the counterflow tunnel furnace and a combustion chamber arranged above for the combustion of carbonization gases from the heat treatment device.

FIG. 6 is a cross-sectional view of the furnace from FIG. 2 in the area of a baking zone;

Fig. 7 is a vertical longitudinal sectional view of the furnace and the combustion chamber along the line 4-4 of Fig. 2;

FIG. 8 is a horizontal longitudinal sectional view of the combustion chamber from FIGS . 2, 4 and 5;

Fig. 9 is a cross-sectional view of another vaulted oven as constructed furnace;

Fig. 10 is another cross-sectional view of the vault of the furnace in the area of Garbrandzone;

Fig. 11 is a longitudinal sectional view of the vault of the furnace;

Fig. 12 is a horizontal longitudinal sectional view of a combustion chamber of the vault furnace.

The plant shown only partially and schematically in FIG. 1 serves for the production of brick products from recent water sediments that have a high content of water and organic substances. The system comprises a raw material store 2 , in which port silt or other water sediments with a water content of about 50% by weight (based on the wet weight) are temporarily stored, from a stale sink, a wet treatment 4 with a classifying device 6 , in which foreign bodies and Coarse material with a grain size of more than 60 microns are removed from the port silt, a heat treatment device 8 with two combined drying and calcining ovens, for example as rotary kilns 10 , 12 for drying or calcining the cleaned port silt, a shaping device (not shown ), in which the calcined harbor silt, if necessary after a previous comminution and / or classification, with the addition of water, is mixed to form a homogeneous moldable mass and shaped into raw bricks or other firing material, and a counterflow tunnel furnace 14 with two firing channels 16 , 18 , in which the kiln is then burned. Instead of a Ge genlauftunnelofens 14 other furnaces can be used to burn the fired material, for. B. the prior art speaking normal tunnel kilns. Share between the individual systems 2 , 4 ; 4 , 8 ; 8 , 14 are conveyor devices 20 (only partially shown) for transporting the untreated, cleaned or calcined port silt or the combustible to the subsequent further processing step.

In the raw material warehouse 2 , the wet processing 4 and the conveying devices 20 are common brick parts, which are therefore not described in detail.

The two calcining furnaces 10 , 12 can be different furnace shapes, for example conventional rotary tube furnaces, such as those used for cement production. In the first calcining furnace 10 , the cleaned harbor silt is dried at temperatures which are just above 100.degree. C., and mercury is expelled, while it is calcined in the second calcining furnace 12 at temperatures between 300 and 700.degree. A burner in which oil, gas or other conventional fuels are burned could be used to heat the calcining furnaces 10 , 12 . However, for heating the calcining furnaces 10 , 12 , smoldering gas can also be used in the respective burners, which is expelled from the water sediments when they are heated. However, at least the serving for calcining calcining furnace 12 is heated by hot furnace gases from the counter-running tunnel furnace 14 of the two calciners 10, 12th

In plants of FIG. 2, in which the drying of the water sediments and their calcination takes place in one process step, the furnace in which the drying and calcination takes place can also be heated via burners which burn, among other things, the smoldering gases formed during the calcination nen. In this case, however, care must be taken to ensure that the heat is distributed within the furnace in such a way that the water sediments are first dried and then calcined.

In a particularly powerful furnace shape, the calcining furnace 12 is designed as a tunnel furnace. This essentially consists of two channels 88 , 89 running parallel to one another. In the upper channel 88 , the material to be calcined is conveyed in one direction 90 and in the lower channel 89 in the opposite direction 91 . The implementation of the material to be calcined takes place with the help of a paternoster 92 , on which a kiln car 42 is converted from the upper channel 88 into the lower channel 89 . This tunnel kiln 87 is arranged above the counter tunnel kiln 14 , which is only shown schematically in FIG. 3. This mating furnace 14 is connected through a very short carbonization 93 with the mating tunnel kiln 14th The hot carbonization gas from the tunnel furnace 87 enters the counterflow tunnel furnace 14 through this short carbonization gas line 93 . In addition, this directly on the counter-running furnace 14 installed tunnel furnace 87 takes up very little space, so that it is particularly well suited for tight spaces.

The material to be calcined is first conveyed through the upper channel 88 in the direction of the paternoster 92 . In the middle of the tunnel kiln 87 in the upper channel 88, the temperature rises relatively steeply from about 100 ° C. to 500 ° C. (cf. the temperature diagram according to FIG. 4). The material to be calcined passes through the upper channel 88 at a temperature of approximately 500 ° C. This temperature is maintained up to about half of the tunnel oven 87 after the heated material has been transferred with the aid of the paternoster 92 in the lower channel. Then the temperature in the lower channel 89 drops to the initial temperature of about 100 ° C. At this temperature, the calcined material arrives on the kiln car 42 in a rotary tipper 94 , which empties the kiln car 42 in the direction of a discharge 95 ent. This discharge 95 is located at an inlet 96 of the counterflow tunnel furnace 14 arranged approximately below the rotary tipper 94 . Similarly, the calcining furnace formed as a tunnel kiln 87 can also be arranged on kilns other than a Ge genlauftunnelofen 14 . This is just a particularly inexpensive example with a high degree of efficiency.

Advantageously, the tunnel furnace 87 can also be designed as a muffle furnace, the muffles 97 of which extend over the entire length of the calcining furnace 12 .

In the area of the material entering the upper channel 88 to be calcined, hot gas is supplied to the upper channel 88 via a screen cleaner 98 . This heats the material to be calcined so that carbonization gases escape from it. In the area of the paternoster 92 , the hot gases are also diverted into the lower channel 89 . In this case, the gas mixture enriched with carbonization gases enters the counterflow tunnel furnace 14 through the carbonization line 93 and is used there, as already described, to burn the combustible material. The gas which cools down is discharged through an exhaust pipe 83 in the region of the center of the furnace. It passes through an exhaust gas cleaning system 84 via an exhaust fan 99 into a chimney 86 through which it leads.

The heating of the calcining and Troc here also kenofens 74 through a hot gas stream from the furnace 14, which is recycled to absorption of water vapor and smolder in the kiln fourteenth The amount of exhaust gas emitted by the furnace 14 is indeed increased by the amount of water vapor. However, this is not a disadvantage if the exhaust gas temperature remains above 100 ° C up to the chimney mouth. The advantage is that neither emissions sources arise during drying nor during calcining, but only a single emission source is present, namely the chimney on the kiln 14 .

There is a transition zone in the temperature range around 100 ° C the one with the last remnants of water vapor be used, but also first, especially light coals leak hydrogen. Practice has contributed to drying about 110 ° C showed that the expelled water vapor so many Contains hydrocarbon components that the condensed Water must be treated before it can be drained can.

In the method described here, however, the water vapor is heated in the firing zone of the furnace 14 to approximately 1,000 ° C. and the components contained in it are subsequently combusted with hydrogen.

Due to the high heat requirement in water evaporation, it is no longer economical to cover the heat requirement of a combined drying and calcining furnace solely with hot gases from the furnace 14 . It is advisable to additionally burn a portion of the carbonization gases expelled in the area of the drying and calcining furnace 74 , which can be done by a combustion chamber attached or installed there. This combustion chamber is also equipped with an oil or gas burner, which is necessary for start-up. The oil or gas burner is also required if the calorific value of the carbonization gas becomes too low (port silt is a waste product in which, among other things, the hydrocarbon content is subject to strong fluctuations).

By combining all emission sources in the furnace 14 , the amount of exhaust gas is increased. Since it leaves the oven at approx. 1000 ° C, it contains large amounts of heat. Therefore, the drying and calcining furnace 74 can be heated particularly economically, if it is designed as a muffle furnace 80 , the muffles 81 of which are flowed through by the entire exhaust gas stream of the furnace 14 . The exhaust gas flow from the furnace 14 emerges from the center of the furnace at approximately 1,000 ° C. and is completely free of uncombusted constituents. However, it must be cleaned of the acidic constituents contained in it and any heavy metals present. To do this, it must be cooled from approx. 1,000 ° C to approx. 200 ° C. This amount of heat to be removed from the exhaust gas flow cannot be recuperated more economically than for heating the drying and calcining furnace 74 . In this case, the calciner 74 would be better not designed as a rotary kiln, but as a continuous furnace with moving grate or as a tunnel furnace traversed by a tunnel kiln car 79 or as the tunnel furnace 87 already described in detail with two superimposed channels 88 , 89 . It can then receive a countercurrent that is customary in tunnel kilns, which is conducted in a closed circuit via a pipe from the material discharge back to the material discharge. In addition, the counter-rotating principle can also be applied. In both cases, the expelled water vapor and the expelled carbonization gases or their combustion products must be brought into the furnace 14 . What is achieved by the countercurrent process in both furnaces is that the heat contained in the calcined material is recuperated inside the furnace, that the process heat requirement of the drying and calcining furnace is reduced, and that the calcined material leaves the furnace so cold that it can be used without any problems and without being expensive After cooling can be processed further.

The furnace gases are removed from each of the two combustion ducts 16 , 18 of the furnace (shown only for one combustion duct) at two spaced locations, one ( 22 ) of the two extraction points 22 , 24 near the center of the furnace, ie is arranged in a region of high temperatures, while the other ( 24 ) is arranged in the direction of flow of the combustion material near the rear end of the combustion duct 16 , 18 , that is to say in a region of low temperatures. The furnace gases are drawn off by two gas lines 26 , 28 , each of which is provided with a controllable throttle 30 for regulating the amount of gas, so that any temperature between that in the middle of the furnace and that at the end of the temperature can be controlled by controlling the amount of gas withdrawn Can adjust combustion channel 16 , 18 . The two gas lines 26 , 28 open into a common gas line 32 through which the furnace gases are then passed into the calcining furnace 12 , which they flow through in countercurrent to the port silt. The dried and still warm harbor silt continuously supplied in the calcining furnace 12 is heated to the desired calcining temperature, the organic constituent parts becoming clogged due to a relatively low oxygen content of the furnace gases of less than 5%, and ver only to a small extent be burned.

The smoldering gases formed during the smoldering of the organic constituents and emerging from the port silt are carried along by the furnace gases, which, after passing through the calcining furnace 12, are passed back through a further gas line 34 to the counterflow tunnel furnace 14 or another furnace suitable for ceramic products, in order to be there to utilize their calorific value in a combustion chamber 36 to burn a carbonization device.

The properties of the calcined harbor silt, such as its residual organic component content, the properties of the fuel, such as its shrinkage, and the properties of the burnout, such as its porosity, density and mechanical strength, depend on the level of the calcination temperature and the duration of the Calcination, which can be changed in a targeted manner by regulating the temperature of the furnace gases supplied to the calcining furnace 12 (as described above) and by the dwell time of the port silt in the calcining furnace 12 .

The counterflow tunnel furnace 14 consists essentially of the combustion channels 16 , 18 arranged next to one another in a furnace body 38 (see FIG. 2) through which the firing material is passed in opposite directions, ie in each case in the opposite direction. The combustion channels 16 , 18 are closed at their ends by gates and are divided into individual zones by locks 40 . The firing stock is stacked on kiln cars 42 , which are driven on rails through the firing channels 16 , 18 . The furnace 14 works as a countercurrent heat exchanger, the countercurrent for both combustion channels 16 , 18 each consisting of the combustible material transported through the adjacent channel. The heat transfer takes place from the already fired hot ren chilled goods arranged in a rear cooling zone of the combustion channel 16 , 18 directly to the heated goods in an adjacent front heating zone of the adjacent combustion channel 18 , 16 . For heat transfer, the middle wall 44 of the furnace, which is arranged between the two combustion channels 16 , 18 , is provided above and below the combustion material 50 arranged on the carriage 42 with through openings 46 , 48 . Due to the temperature difference between the hotter refrigerated goods and the cooler goods to be heated, a natural cross-convection flow arises through these through openings 46 , 48 , which provide heat transport.

The furnace gases enriched with calcining the port silt with carbonization gases are burned in the combustion chamber 36 with the supply of atmospheric oxygen. The hot combustion gases generated during the combustion are introduced for heat recovery through a hot gas duct 52 connected to the combustion chamber 36 into a cooking zone 54 of the furnace 14 arranged behind the heating zone, where they are used to heat the combustion material 50 to a final temperature of 800 to 900 ° C . The combustion chamber 36 is arranged above one of the combustion channels 16 , 18 , as shown in FIGS. 2 to 4, but can also be arranged in the middle wall 44 . Alternatively, the combustion chamber can be arranged separately from the counterflow tunnel furnace 14 in the vicinity of the drying furnace 10 or calcining furnace 12 , 74 , the combustion gases generated during the combustion in this case being used in whole or in part for drying the port silt in the drying furnace 10 .

In the illustrated embodiments, the combustion chamber 36 extends in the longitudinal direction of the furnace 14 over part of its length. The combustion chamber 36 is connected at one end to the gas line 34 through a plurality of gas inlets 56 through which the furnace gases enriched with carbonization gas can be sucked into the combustion chamber 36 . In the combustion chamber 36 are several Hochgeschwin speed burner 60 are arranged, which combustion air from the outside and a combustible gas, for example natural gas can be supplied, which emerges at a relatively high speed from the burner mouthpiece, causing the furnace gases enriched with carbonization gas due to the pulse of the injected gas mixture are sucked in through the gas inlets 56 arranged behind and / or next to the burner mouthpiece and then burn them together with the combustible gas in front of the burner mouthpiece.

The burner 60 have the task of first heating the combustion chamber 36 to the necessary ignition temperature of the furnace gases enriched with Schwelga sen, for. B. to 800 ° C. Since the furnace gases enriched with carbonization gases already have a temperature between 300 and 600 ° C, which corresponds to the temperature at their exit from the calcining furnace 12 , no great expenditure of energy is required for heating. After the furnace gases enriched with carbonization gases have been ignited, they are burned with excess air on the high-speed burner 60 . Whose gas supply is controlled depending on the temperature of the combustion gases, while the amount of combustion air supplied to the burner 60 generally remains constant. With increasing energy yield from the combustion of the furnace gases enriched with carbonization gases, the gas supply to the burner 60 is thus regulated, that is to say the ratio between natural gas and combustion air is reduced.

The burners 60 are arranged at an acute angle to the furnace along the longitudinal axis, so that the burner jet inherent pulse for the transport of the hot combustion gases in the direction of the longitudinal center of the combustion chamber 36 and the hot gas channel 52 is used. The burners 36 have protective tubes permanently installed in the furnace wall, but can otherwise be dismantled and serviced from the outside. For example, the best existing burner mouthpiece made of SiC or another heat-resistant material is releasably attached to the burner 60 so that it can be replaced.

The combustion gas generated during the combustion reaches temperatures that are above the cooking burn. The combus- tion gas is driven by the pulse of the burner jet in the direction of the longitudinal center of the combustion chamber, which on the one hand increases the negative pressure which draws the furnace gases enriched with carbonization gases from the gas line 34 , and on the other hand the combustion gases are swirled and homogenized in the process. From the combustion chamber 36, the combustion gases are passed through the hot gas channel 52 into the baking zones 54 of the baking channels 16 , 18 arranged essentially in the middle of the furnace, where they heat the material 50 to its baking temperature. The entry of the hot combustion gases from the hot gas channel 52 into the combustion channel 16 , 18 it follows via a plurality of passage openings 62nd

The passage openings 62 contain regulating elements (not shown), for. B. externally operable fireclay valve, which make it possible to control the amount of combustion gases and the locations at which they are introduced into the combustion channels 16 , 18 , so that a predetermined temperature profile arises along the combustion channels 16 , 18 . In order to take into account the relatively low flow rates of the hot combustion gases, the passage openings 62 for the combustion gases must be relatively large and have relatively low flow resistances.

After flowing through the baking zone 54 of the combustion channels 16 , 18 , the combustion gases, which have given off part of their heat to the material to be fired and now have a temperature of approximately 750 ° C., are passed through a heat exchanger (not shown) to a part of the Recover residual heat, for example in the form of hot water for heating. Alternatively, they can also be used to heat the drying oven 10 .

In the counterflow furnace 14 shown in FIGS . 9 to 12, designed as a vault furnace, the combustion chamber 36 and the hot gas duct 52 are arranged directly above the vaulted ceiling of the respective combustion duct 16 , 18 . The hot combustion gases are preferably returned between two arches 68 , 70 arranged one above the other, and from there through perforations, slots 72 or other openings in the lower arch 70 into the combustion channel 16 , 18 .

The port silt can be added to reduce the sintering temperatures to be achieved in the Brennkanä len 16 , 18 combustion products. These can come from large-scale industrial boiler plants, for example from waste incineration plants. The combustion products generated in a waste incineration plant, ie slag, boiler ash or filter dust have a very fine consistency and are therefore particularly well suited for mixing with the water sediments, ie the harbor silt.

These combustion products are added to the water sediments prepared in the wet treatment 4 when these are conveyed via the conveying device 20 in the direction of the combined drying and calcining furnace 74 . For this purpose, a dosing device 82 is provided above the conveyor 20 , with which a quantity of the combustion products to be dosed is added to the water sediments. This metering device 82 is primarily controlled depending on the amount of Ge water sediments conveyed on the conveyor 20 . In addition, however, a further control can be superimposed, which takes place depending on the respective constituents of the water sediments.

The mixture of water sediments and combustion products then enters the calcining and drying oven 74 and is heated there to a calcining temperature of at least 400 ° C. The combustion products are thermally pretreated at this temperature. From these chlorine compounds, such as. B. aluminum chloride, sodium chloride, potassium chloride, iron chloride and other chlorine compounds driven out, together with the water and the smoldering gas that emerges from the water sediments. The large number of possible compounds that emerge from the combustion products results from the undefined composition of the waste that is passed through in a waste incineration plant.

These exhaust gases, now enriched with the chlorine compounds, are conveyed through the gas line 34 in the direction of the combustion chamber 36 , as already described. After the combustion taking place there, the hot exhaust gases are conveyed back through the gas line 32 into the combined drying and calcining furnace 74 .

A portion of the exhaust gases is removed from the drying and calcining furnace 74 via an exhaust gas line 83 and passed through an exhaust gas purification system 84 . There, the flue gas enriched with the chlorine compounds is cleaned of the chlorine-containing components with the help of a calcareous absorbent. These form salts with the lime component, which fail in the exhaust gas cleaning system 84 and can be disposed of separately. The exhaust gases cleaned in this way leave the combined drying and calcining oven 74 via a disposal line 85 in a chimney 86 , through which the cleaned exhaust gases can be released without hesitation.

Similarly, in the system example shown in FIG. 1, the exhaust gas to be cleaned can be removed from the calcining furnace 12 and cleaned in an exhaust gas cleaning system. The exhaust gas cleaned in this way is then also disposed of in this embodiment via a chimney.

Claims (75)

1. A process for the production of brick egg products from recent water sediments with a high content of water and organic substances, in which moldings are produced from a heat-treated Ge water sediment and moisture-containing mixture and these moldings are then fired, characterized in that the moldings from a Mixture are prepared which, in addition to the heat-treated water sediments, contains no further components consisting of water sediments or clay, that the water sediments are calcined during the heat treatment, and that the moisture is introduced into the mixture by adding water to the calcined water sediments. 2. The method according to claim 1, characterized in that the Mixture additives for changing the color, the surface quality, sintering properties, frost resistance, the tendency to bloom and / or the firmness of the goat contains lyre products. 3. The method according to claim 2, characterized in that the Mixture to lower the melting point a sintering agent is added. 4. The method according to claim 2 or 3, characterized in that combustion products are added to the mixture. 5. The method according to any one of claims 2 to 4, characterized indicates that kettle ash is added to the mixture. 6. The method according to any one of claims 2 to 5, characterized records that filter dust is added to the mixture. 7. The method according to any one of claims 2 to 6, characterized records that slag is added to the mixture.   8. The method according to claim 7, characterized in that the Mixture of ground slag is added. 9. The method according to any one of claims 4 to 8, characterized records that the combustion products at least partially be taken from a waste incineration plant. 10. The method according to any one of claims 1 to 9, characterized ge indicates that the mixture has an addition of 3% to 20% is added to combustion products. 11. The method according to claim 10, characterized in that the mixture an addition amount of 5% to 10% of scalds added products. 12. The method according to any one of claims 4 to 11, characterized ge indicates that the combustion products at at least 400 ° C be thermally pretreated. 13. The method according to claim 12, characterized in that the combustion products are calcined. 14. The method according to claim 13, characterized in that the combustion products of the freshly delivered waters Dimenten mixed and calcined together with them the. 15. The method according to claim 14, characterized in that the mixture of water sediments and combustion products dried in one oven and calcined in another oven becomes. 16. The method according to claim 14, characterized in that the mixture of water sediments and combustion products dried in the same oven in which it is calcined.   17. The method according to claim 15 or 16, characterized in net that a chlorine-containing exhaust gas leaving the furnace Emission control system is supplied. 18. The method according to claim 17, characterized in that the chlorine-containing exhaust gas in a calcareous absorbent is inclined. 19. The method according to claim 17 or 18, characterized in net that the chlorine-containing exhaust gas together with a mixture from carbonization gas and water vapor into one for burning the mold intended furnace is discharged from which it is a minimum temperature of 400 ° C in the exhaust gas purification location is derived. 20. The method according to any one of claims 1 to 19, characterized ge indicates that the water sediments before calcining be dried. 21. The method according to any one of claims 1 to 20, characterized characterized that the water sediments work in the same calcined and dried. 22. The method according to any one of claims 1 to 21, characterized ge indicates that the moisture content of the water sedi elements before drying by settling and / or mechanical loading action is reduced. 23. The method according to any one of claims 1 to 22, characterized ge indicates that calcined Ge water sediments are mixed, which come from different Waters. 24. The method according to any one of claims 1 to 23, characterized ge indicates that for the preparation of the mixture Gewässersedi elements that were previously mixed at different temperatures fittings have been calcined.   25. The method according to any one of claims 1 to 24, characterized ge indicates that the water sediments at temperatures between calcined between 300 and 700 ° C. 26. The method according to any one of claims 1 to 25, characterized ge indicates that when calcining the water sediments formed agglomerates or lumps before making the Mi be crushed. 27. The method according to any one of claims 1 to 26, characterized ge indicates that the grain size distribution in the mixture controlled by changing the conditions during calcining becomes. 28. The method according to any one of claims 1 to 27, characterized ge indicates that the grain size distribution in the mixture by changing the temperature and / or length of stay at Calcination is controlled. 29. The method according to any one of claims 1 to 28, characterized ge indicates that the grain size distribution in the mixture by classifying at least part of the calcined Ge water sediments is changed. 30. The method according to any one of claims 1 to 29, characterized ge indicates that the calcined water sediments between 5 and 10% by weight water and preferably about 7% by weight water be added. 31. The method according to any one of claims 1 to 30, characterized ge indicates that the water sediments during calcining min at least partly by hot furnace gases one for burning the Shaped kiln used to be heated. 32. The method according to claim 31, characterized in that  the furnace gases in at least two places with different Temperatures are extracted from the kiln. 33. The method according to claim 32, characterized in that the quantities of the furnace gases withdrawn are controlled, to set a desired temperature. 34. The method according to any one of claims 1 to 33, characterized ge characterizes that when calcining the water sediments expelled carbonization gases are burned. 35. The method according to claim 34, characterized in that at least part of the energy generated during combustion is used to burn the moldings. 36. The method according to claim 34 or 35, characterized in net that the energy generated by the combustion min Mostly used to dry the water sediments becomes. 37. The method according to any one of claims 34 to 36, characterized ge indicates that the energy generated during combustion at least partially for calcining the water sediments is used. 38. The method according to any one of claims 33 to 35, characterized ge indicates that the smoldering gases from hot furnace gases in one kiln used to burn the moldings become. 39. The method according to any one of claims 34 to 38, characterized ge indicates that the carbonization gases with the addition of oxygen and burned a fuel in a combustion chamber, and the hot combustion gases from the combustion chamber in the furnace.   40. Plant for carrying out a method for producing brick products from recent water sediments comprising a heat treatment device for heat treatment of the water sediments, a kiln for burning mold and at least one gas line connecting the kiln and the heat treatment device for supplying hot furnace gases to the heat treatment device, thereby indicates that the heat treatment device ( 12 ) and the kiln ( 14 ) are connected by two gas pipes ( 26 , 28 ) opening into the kiln at a distance from one another, one of which is in a range of high temperatures and one in a range of low temperatures opens, and that the quantity of flow in the gas lines ( 26 , 28 ) can be regulated. 41. Plant according to claim 40, characterized in that the heat treatment device ( 12 ) is set up for calcining the dried water sediments. 42. Plant according to claim 40, characterized in that the heat treatment device ( 12 ) is set up for drying the moist water sediments. 43. System according to claim 41 or 42, characterized in that that the heat treatment device for drying the moist Water sediments and for calcining the dried Water sediments is set up. 44. Plant according to claim 43, characterized in that the heat treatment device ( 74 ) suitable for drying and calcining is designed as a muffle furnace. 45. Plant according to claim 44, characterized in that the muffle furnace is formed by muffles which are flowed through by the entire gas stream from the furnace ( 14 ). 46. Plant according to one of claims 43 to 45, characterized in that the heat treatment device ( 74 ) for drying and calcining is formed as a continuous furnace with moving grate. 47. Installation according to one of claims 43 to 45, characterized in that the heat treatment device ( 74 ) for drying and calcining is designed as a tunnel kiln ( 87 ) passed through by a tunnel kiln car ( 79 ). 48. System according to one of claims 40 to 47, characterized in that the tunnel kiln ( 87 ) is provided immediately above the kiln. 49. Installation according to claim 48, characterized in that the tunnel furnace ( 87 ) is connected to the furnace by a short carbonization line ( 93 ). 50. Plant according to claim 48 or 49, characterized in that within the tunnel furnace ( 87 ) two mutually parallel ver channels ( 88 , 89 ) are provided, which are successively passed through in time order by a product to be calcined. 51. Installation according to claim 50, characterized in that the two channels ( 88 , 89 ) run in the vertical direction with each other. 52. Apparatus according to claim 51, characterized in that in an upper channel ( 88 ) the material to be calcined is strongly heated approximately in the central region and is cooled in a lower channel in the direction of a feed station. 53. Plant according to one of claims 48 to 53, characterized in that furnace wagons ( 42 ) are provided for conveying the material to be calcined, a conveyor for the implementation of one channel ( 88 ) in the other channel ( 89 ) is seen. 54. Plant according to one of claims 48 to 53, characterized records that an unloading device for the calcined material is provided. 55. Installation according to one of claims 40 to 54, characterized in that the kiln is formed as a counterflow tunnel kiln ( 14 ) and has two combustion channels ( 16 , 18 ). 56. System according to one of claims 40 to 55, characterized in that the one gas line ( 26 ) in the vicinity of the furnace opens into the center of the kiln ( 14 ), while the other gas line ( 28 ) in the vicinity of an end of the furnace the kiln ( 14 ) opens. 57. Installation according to one of claims 40 to 56, characterized in that the gas lines contain devices ( 30 ) for control of the flow rates. 58. Plant according to one of claims 40 to 57, characterized in that the heat treatment device ( 12 ) is connected by a further gas line ( 32 ) with a device for burning the carbonization gases expelled from the water sediments during calcining. 59. Plant according to claim 58, characterized in that the carbonization device comprises a combustion chamber ( 36 ). 60. Plant according to claim 59, characterized in that the combustion chamber ( 36 ) is arranged inside the kiln ( 14 ) or in the vicinity thereof. 61. Installation according to claim 59 or 60, characterized in that the combustion chamber ( 36 ) is arranged in the vicinity of a drying oven ( 10 ) in which the water sediments are dried before calcining. 62. Plant according to one of claims 59 to 60, characterized in that the combustion chamber ( 36 ) is arranged in the vicinity of a furnace for calcining the dried water sediments. 63. Installation according to one of claims 59 to 62, characterized in that the combustion chamber is equipped with at least one burner ( 60 ). 64. Plant according to claim 63, characterized in that the Burner with atmospheric oxygen and a flammable medium is beatable. 65. Installation according to one of claims 59 to 64, characterized in that the gas line ( 34 ) through at least one gas inlet ( 56 ) opens into the combustion chamber, and that the burner ( 60 ) is arranged such that the gas inlet ( 56 ) a negative pressure is generated. 66. Installation according to one of claims 56 to 65, characterized in that the gas inlet ( 56 ) is arranged behind or to the side of a mouthpiece of the burner ( 60 ). 67. Installation according to one of claims 40 to 66, characterized in that a metering device ( 82 ) is provided with which a measured amount of combustion products can be introduced into the water sediments. 68. Installation according to claim 67, characterized in that the metering device ( 82 ) is adjustable to a quantity ratio of the water sediments to combustion products of 3% to 20%. 69. Plant according to claim 67 or 68, characterized in that the metering device ( 82 ) is provided in the conveying direction of the water sediments in front of the drying oven ( 10 , 74 ). 70. Plant according to claim 61, characterized in that the metering device ( 82 ) is aligned with the water sediments to be dried. 71. Installation according to claim 70, characterized in that the metering device ( 82 ) is aligned in a mixer which mixes the water sediments with the combustion products. 72. Installation according to one of claims 67 to 71, characterized in that an exhaust gas purification system ( 84 ) is provided with which at least chlorine compounds can be extracted from the exhaust gas. 73. Installation according to claim 72, characterized in that the exhaust gas purification system ( 84 ) is provided before the exhaust gases enter a chimney ( 86 ). 74. System according to claim 72 or 73, characterized in that the exhaust gas cleaning system ( 84 ) is designed for an operating temperature of at least 400 ° C. 75. Installation according to one of claims 72 to 74, characterized in that the exhaust gas cleaning system ( 84 ) is provided at an outlet of the exhaust gases from the calcining furnace ( 12 , 74 ).