CH634536A5 - METHOD FOR RECYCLING AND WASTE WATER TREATMENT AND MULTI-STAGE FILTRATION DEVICE FOR CARRYING OUT THIS METHOD. - Google Patents

Description

The invention relates to a method for waste recycling and waste water treatment, the waste water being mixed with the comminuted waste, the waste water stream with the dissolved and suspended constituents of the waste being passed through a two-stage filter made of non-activated and activated coal, in a first reactor Multiple reactor kiln the major part of the filter coal saturated with dirt load is thermally treated for regeneration, whereby the dirt load which has been attached to the carbon filter is thermally decomposed to produce coal and fuel gas, in at least a second reactor waste or part of the filter coal saturated with dirt load is burned to produce heat and fuel gas, and the

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Regenerated filter coal of the first reactor is used again to filter the waste water.

The invention further relates to multi-stage filtration devices for performing the method.

From DE-OS 2 558 703 by the applicant a method of the type mentioned is known. This procedure is simple and economical at the same time

(1) the waste water is used as a means of transport for the waste and for its separation into essentially inorganic and organic components;

(2) the waste water contaminated with the waste is purified by filtration using normal and activated carbon;

(3) part of the garbage or the activated carbon loaded with dirt is burned with the emission of a fuel gas which provides energy for the thermolysis; such as

(4) the main part of the filter coal loaded with dirt is thermally decomposed in a thermolysis reactor, whereby the filter coal is regenerated and a hydrocarbon-rich carbonization gas is obtained.

Although many advantages are achieved by this method and in particular an optimal use of the energy content of the waste as well as its utilization is also made possible for the treatment of waste water, difficulties have still been shown in the practical implementation of the method. These occur in particular when garbage of constantly changing starting composition is entered into the system and at the same time a variation in the composition of the wastewater also supplied can be observed. This, but also due to particularly stubborn, unpleasant contaminants, can in particular lead to difficulties in the separation and filtration processes which are vital for the system. The continuous processing of waste and wastewater can be hindered in particular by clogging or sticking of the carbon filter, changes in flow and excessive abrasion of the filter carbon. This can also lead to the passage of contaminants through the fine filters loaded with activated carbon, in particular polar substances.

The invention is therefore based on the object of improving the filtration processes and separation processes in a simple and continuously manageable manner in the process of the type mentioned at the outset. Here, in particular by varying the filter conditions or by creating novel filtration devices and their handling, an improvement in the adhesion processes of the contaminants to the filter media is to be achieved without the passage of the waste water to be cleaned being impeded. Through targeted variation of the filter media, using the waste generated, the filter effect that can be achieved is to be improved with additional detection of strongly polar substances.

This object is achieved in that the waste water loaded with waste is passed through a multi-stage filtration system in which the coarse filtration is effected by loose beds of adsorption carbon, which was obtained from the organic components of the waste, and the beds loaded with organic contaminants for thermal purposes Treatment of the same can be returned to the multi-reactor kiln to obtain adsorption coal.

The invention is largely based on the knowledge that the use of a multi-stage filter system in which the filtration processes are carried out at least in part by loose beds containing coal enables the disadvantages previously observed to be avoided. By dividing the filtration processes into several stages and in particular by inserting coarse filters, which contain loose fillings of filtration material, mechanical and partly also adsorptive separation of the dirt load of the waste water is possible without clogging or sticking of the perforated walls , Sieves and the like of the filtration devices comes. The blockage or sticking of the perforated walls of the filtration device or the corresponding sieve units is advantageously avoided by moving the filters to improve the filtration effect in such a way that a constant movement of the bulk material is brought about. Suspended particles in the wastewater are adsorbed on the adsorption carbon without the perforated sieve surfaces sticking together. As a result, the emptied filter systems can be refilled with fresh filtration material in a continuous manner and thus an undisturbed sequence of the filtration processes. The discharged fillings, which are loaded with dirt, are then returned to a reactor of the multiple reactor kiln for subsequent coking of the contaminants while obtaining new filtration coal.

It is expedient to carry out the filtration through loose fillings in suitable devices as a coarse filtration before a further filtration and clarification of the waste water carried out by further filter units containing non-activated and activated coal. Although it is possible to switch a mechanical computer in front of the pre-filter, which has a loose bed of filtration material that contains coal, the latter can also be completely replaced by the pre-filter itself, since the filtration by means of bulk material clogs the apparatus Parts of the filtration devices are largely excluded.

The prefilters, which serve as the first coarse filters, are generally guided in countercurrent to the contaminated wastewater that passes through, with filtration being carried out due to the effects of gravity. However, the coarse filters can also be introduced in rotating wastewater or moved by flowing wastewater.

The beds of filtration material contain significant amounts of coal or adsorption coal. In the case of the coarse filters to be passed first, the adsorption carbon is generally in non-activated form.

Depending on the type of composition of the wastewater to be treated or its contamination, the coarse filter can also have a certain proportion of activated coal added to it, which is also obtained from the organic components of the waste.

According to a preferred embodiment of the invention, the beds contain coal in the pelletized state in order to keep the abrasion of coal dust as low as possible. This pelletization of the bulk coal is preferably carried out for fine filtration. In this case activated coal is preferably used. For this purpose, the coal generated from waste in the first reactor by thermal regeneration is advantageously finely ground after cooling, with organic binder, such as Tar, briquette pitch, mixed and at elevated temperature and pressure, e.g. 80 ° C compacted at a pressure of 1200 kp / cm2. This compacted coal can then be brought back to the desired average grain size by grinding. It then represents non-activated filter coal suitable for coarse filtration. If the coal is to be used for the fine filter, the resulting granulate is activated in a manner known per se, for example by heat treatment for several hours in the gas-tight reactor of the multiple reactor kiln can be done with the introduction of water vapor and / or zinc chloride. The pelletized activated carbon obtained from the organic constituents of the waste has good abrasion resistance combined with high surface development.

Such pelletization allows abrasion resistance5

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largely avoid the effects of coal and related disruptions.

Particularly favorable filtration effects are achieved with loose carbon filtration material, which also contains a proportion of polar substances. This proportion of polar substances can be achieved by admixing the waste and / or wastewater with those waste materials that are present in the heat treatment in a form that promotes filtration and in some cases actively participates in adsorption. This can be achieved, for example, by adding a certain proportion of waste water from paper production or also porcelain processing to the household and industrial waste to be treated, which is applied to the waste water, usually municipal waste water. Waste or waste water from this industrial area usually contain polar substances, e.g. Fillers, such as aluminum oxides, silicon oxides, titanium oxides etc., which, when converting the existing organic constituents into coal, at the charring temperatures in the range from approx. 800 ° C can be obtained in activated form. Other possible polar metal oxides that often carry a low positive charge are, for example, iron oxides and magnesium oxides, such as are produced as waste sludges in the ceramic and aluminum-producing industries. The targeted admixing of waste sludge, which results in activated polar oxides during charring, can not only achieve additional filtration effects on the mechanical carbon filters due to polar electrostatic effects, but also has a favorable effect on the clarification and sedimentation behavior of the waste water . Therefore, in addition to pelletizing the bulk material, this measure of the composition of the loose bulk material from both coal and polar waste substances is particularly preferred when carrying out the process according to the invention. This applies in particular with regard to fine filtration.

According to a further embodiment of the method according to the invention, at least the fine filters are backwashed with process water before the emptied bed is emptied, which is preferably removed from a partial stream of already cleaned wastewater.

The filtration processes using loose bulk material, preferably in pelletized form, can still be favored if a constant movement of the bulk material is achieved. When moving the bulk material, for example by moving the container that houses it, care must be taken to ensure that it does not reach a fluidized bed state, since this removes the mechanical filter effect.

In a further embodiment, the method according to the invention is carried out in such a way that the filtration system is filled with filling material in continuous operation, then flowed through with waste water laden with waste, if necessary after being washed back, freed of the loaded filling material, and after refilling with filling material is used again for filtration. These different measures taken in continuous operation can be achieved, for example, at spatially separate stations of a single filtration device.

Exemplary embodiments of a multi-stage filtration device for carrying out the method according to the invention are described below with reference to the drawing.

Show it:

La, lb schematically the sequence of the inventive method for waste recycling and wastewater treatment,

Fig. Lc a rotating bucket filter that can be used both as a coarse and fine filter,

Fig. 2 shows a band filter, and

3a, 3b a continuously operating filtration belt. In Fig. La, the main filtration process in the inventive method is shown, the reactors of the multiple reactor kiln required in the system for the regeneration and optionally combustion 5 of the loaded filtration coal, in which also the organic components of the waste in coal, partly in activated, to Part of non-activated form, can be transferred, and waste can be incinerated, are not shown. 10 The method according to the invention will now be explained separately on the basis of the route that the waste water and solid waste take:

The wastewater, which may include both urban wastewater and industrial wastewater, is discharged through a wastewater inlet duct 108 via a nozzle system 170 in which gas injection, e.g. Air, mixing and fine distribution of the introduced contaminants takes place to a settling basin 110, a sieve 112 and then to a multi-stage filtration device 106. A prefilter 142, which is a coarse filter and can be lowered into the waste water, is provided in front of the multi-stage filtration device 106. This pre-filter serves to trap very heavy or stubborn impurities and can - if this is desired - even replace the mechanical rake or sieve 112 completely. This pre-filter 142 rotates in countercurrent to the waste water passing through it. In a preferred embodiment of the invention, as shown in FIG. 1b, the pre-filter consists of individual filter elements 144 which contain a bed of coal, the filter elements being arranged on a slowly or intermittently moving chain conveyor 146 or the like which the filter element in the direction of the arrows in Fig. 2 in the wastewater flow at the outflow end 148 of the pre-filter and then transported in the counterflow direction upstream to the upstream point 150 35, at which the now loaded individual filter elements are withdrawn from the water flow in the upward direction. An advantage of this design of the rotating prefilter is that the dwell time of the filter elements in the wastewater can easily be regulated depending on the observed degree 40 of the impurities by increasing or decreasing the speed of the conveyor chain 146 accordingly. Naturally, such or a similar construction can also be used for the subsequent coarse filters 114 and fine filters 116.

45 The filter elements 144 of the pre-filter 142 generally comprise a suitable frame which contains a loose bed of at least a portion of coal particles, preferably in pelletized form. This frame is perforated in its area that is filled with the fill in order to allow liquid to pass through. After removing the filter elements from the wastewater flow, the dirt-laden coal beds are conveyed by means of conveyor chain 146 to a reactor of the multiple reactor kiln (not shown in the figure), in which the regeneration of the coal and a simultaneous pyrolysis of the adhering organic impurities take place. As a result, the contaminants are directly converted into reusable filter coal. It is advantageous here to provide a drip-off device for the filter elements, through which liquid adhering to the loaded filter carbon is removed as best as possible before it is regenerated and / or burned. This drainer may include, for example, a shaking mechanism (not shown) to improve water removal.

The now empty filter elements 144, the perforated 65 sieve surfaces of which have been preserved by the bed in the unglued or not clogged state, can now be used with fresh, regenerated coal from a reactor of the multiple reactor kiln (not shown in the figure, but also with

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“Oven”). In this case, it may be expedient, which is not shown in the figure, to optionally provide intermediate washing processes in the event of faults. The empty filter elements 144 are then returned to the pre-filter 142 with fresh coal fill. Between the coal outlet of the reactor (not shown) and the prefilter, a heat collector 156 can be used to cool the hot regenerated coal and to transfer the heat of the coal to heat-transporting media, e.g., via suitable heat exchanger devices (not shown separately). Water.

The rotating prefilter 142 will already remove a large part of the particles suspended in the water in a relatively simple manner. Furthermore, it can be seen from the figure that the floated or suspended, primarily organic contaminants which have been collected by the sieve or the rake 112 can be discharged from the waste water by means of an upwardly directed conveyor belt 132 and fed to the combustion or charring. Here, the conveyor 132 is constructed or arranged in such a way that a relatively unimpeded passage of water is possible during the detection and removal of the flourishing and suspended particles.

The wastewater pre-cleaned by the pre-filter 142, possibly with the support of the sieve 112, now enters a system of coarse filters 114 and fine filters 116 before it exits as service water via the outlet channel 118.

The coarse filter 114 consists of a large number of coarse filter elements 120 which, by lifting and lowering the coarse filter, can leave it for regeneration or be returned to it. The filter elements 120 are usually filled with adsorption carbon of suitable particle size, preferably in pelletized form. The filter elements are moved in countercurrent operation from the end of filter 122 to the beginning of filter 124.

The fine filter 116 also consists of a series of filter elements 126, which are also moved in stages in countercurrent to the waste water from the lower end 128 to the upper end 130. The fine filter can be cleaned by backwashing, if appropriate in the backwashing devices 134 provided for this purpose. The backwashing water is preferably taken directly from the service water channel 118 and, if desired, can be stored in the reservoir 136, which is equipped with heating spirals 138. The water contaminated by the backwash flows back through a return line to the wastewater inlet 108.

After the backwashing process has ended, the filter element 126 can be fed back into the fine filter 116 for reuse. However, backwashing is only an optional measure, since the usual regeneration of the individual fine filter elements loaded with dirt takes place by thermal treatment in the first reactor of the multiple reactor kiln. If this is desirable,

the adsorption coal loaded with dirt can also be burned in the second reactor to produce heat and fuel gas.

When a thermal regeneration of the adsorption carbon loaded with dirt load has been carried out, the containers of the fine filter elements 126 are filled with fresh adsorption carbon, the heat content of which is still used within the heat collection device 156 before it is introduced into the waste water.

If one now follows the route of the predominantly solid waste to be processed, which includes food waste, paper, plastics, oil and tar residues, old tires, wood, glass, ash, etc., this becomes a bunker 160 via a magnetic tape 162 , A conveyor belt 166, the crushing rollers 164 subjected to a first treatment or separation. In the settling basin 110 the substances with a density 1 are left to settle and with the help of a conveyor, e.g. the cup conveyor 168, removed. The row of air nozzles 170 facilitates thorough mixing 5 of waste water and waste to improve the desired separation into organic and inorganic constituents. The floating organic constituents of the refuse are removed from the rake 112 via the conveyor 132 and transferred to the reactor for coking. Thereby, in the multiple reactor kiln, in the individual reactors, which are arranged in close spatial proximity to one another (not shown in the figure), thermolysis and pyrolysis of both the mechanically removed impurities, the loaded bulk coal and other 15 carbon filters take place, one in a targeted mass some direct introduction of waste into the reactors can be provided.

Another preferred embodiment of a prefilter 188, which can also be used as a fine filter, is shown in FIG. 1c. This consists essentially of a system of tiltable, open-topped open buckets 182 rotating on a guide 180, the bottom wall 184 of which is perforated and which contains the loose filtration material 186, the guide 180 unloading the loaded filtration material and reloading it with fresh one Filtration material 25 made possible, for example, by a tilting movement, deflection movement, weight-based positive guidance, etc. As can be seen from FIG. 1c, the individual containers 182, shown here as buckets, run towards the wastewater, which unloads its dirt load onto the bulk material and then passes through the perforated bottom wall. Depending on the speed, loading of the wastewater with contaminants, etc., the filtration can be easily adapted to the needs in that a correspondingly selected number of containers 182 are directed towards the wastewater. As a result, wastewater can be passed through only one or more containers as desired, especially since the individual containers can also be expediently moved out of the wastewater inflow 194 laterally around the guide 180 or into it. That e.g. 40 emptying of the loaded filtration material provoked by deflection movement leads the dirt-laden filtration materials to a belt 190 leading to the furnace. The containers 182 are then refilled with the material to be filtered using a conveyor device coming from the furnace, e.g. Volume 192.

43 This device has proven itself extremely well for the changing needs of the continuously operating wastewater recycling plant, since it both avoids clogging of the filter media by simply supplying and removing filter material, as well as by easy connection 50 of containers 182, the speed of which is greater than that Wastewater is still controllable, also represents a very flexible system.

FIG. 2 shows a likewise suitable filtration device, which represents an endless bucket filter 330 on a belt 55, which can be introduced into the waste water stream at a suitable location. The bucket filter generally comprises a pair of conveyor belts 332 which are driven by rollers 334 such that the upper part of the belt 336 moves upward to the top left as shown in Fig. 2, there is one on the belt Arranged row of open-topped buckets, the fixed bottom surfaces 340 can be square, rectangular or the like and which by a pair, for example triangular, side walls 342 are completed. The individual buckets are connected to one another by upstanding perforated walls 65 344 through which the waste water to be cleaned passes, leaving the suspended contaminants on the bulk filtration material. A protection of the

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perforated sieve walls achieved and thereby a continuous operation of the process possible. As can be clearly seen from FIG. 2, a loading with fresh filtration material or an emptying of the dirt-laden filtration material can easily take place on the respective end sides of the arrangement.

It is preferred that the bottom surface of the buckets 338 structure, e.g. is nubbed, in order to prevent strong shifts in the bulk solids as far as possible. For this purpose, further subdivisions of the surface of the individual containers can optionally be made, which is preferably done in the longitudinal direction.

3a and 3b, finally, a device 400 that can be used as a prefilter and / or as a fine filter is shown in cross-section and longitudinal section, which essentially comprises a circumferential perforated endless belt 402, which is located at spatially separated stations 420, 430, 440 with filtration bulk material loaded, flowed with loaded wastewater and freed from the dirt-laden bulk material. As shown in FIG. 3 b, fresh filtration material is applied in the loading area 440 by a conveyor device 428 coming from the furnace, while the bulk material mass loaded in the flow area 420 is then appropriately tipped onto a belt 426 leading to the furnace in the unloading area 430. Here, the belt can be operated via suitable drive elements 422, which are preferably located outside the flow area.

According to a preferred embodiment of the method according to the invention, the circulating belt is guided V-shaped in its flow area 420, V-shaped or flat in its loading area 440 and flat on the drive elements 422 in its unloading area 430 in an inclined or tilted position. Such a V-shaped guidance of the band 402 in the flow area can be seen in FIG. 3a. Here, the band 402 is guided on drive rollers 404, 5 with the filter material 406 being located on the surface structure 412 of the band. This or a similar surface structuring can in turn prevent excessive displacement of the filtration material. In FIG. 3a, the deposition of dirt particles is denoted by 410, while the water 408 emerges at 424 through the porous band.

It is pointed out that the belt can be operated continuously at different speeds or intermittently. Here too, the continuous i5 supply and discharge of bulk solids allows surface protection for the otherwise easily clogged, perforated filter element parts.

It is easy to see that the introduction of filter elements, which experience continuous protection of the perforated screen surfaces of the system by filtration material, which can also be conveniently fed and removed in a continuous manner, enables flexible and trouble-free operation of the overall system. This is particularly due to the pelletization of the carbon materials used in the pre-25 filters, coarse filters and fine filters, as well as the targeted presence of parts of polar materials that can also be obtained from waste or waste water, especially calcined metal oxides, such as Iron oxide, aluminum oxide, silica, etc., as they arise from the 30 multiple reactor kiln, are also favored.

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Claims (20)

634 536 2nd PATENT CLAIMS 1. Process for waste recycling and waste water treatment, whereby the waste water is mixed with the shredded waste, the waste water stream with the dissolved and suspended components of the waste through a two-stage filter. ter is led from non-activated and activated coal, in a first reactor of a multiple reactor, the majority of the filter coal saturated with dirt load is thermally treated for regeneration, the dirt load which has been deposited on the carbon filter being thermally decomposed to produce coal and fuel gas , in at least a second reactor waste or part of the filter coal saturated with dirt load is burned to obtain heat and fuel gas, and the regenerated filter coal of the first reactor is used again for filtering the waste water, characterized in that the waste-laden. Waste water is passed through a multi-stage filtration system in which the coarse filtration is effected by loose beds of adsorption coal, which were obtained from the organic constituents of the waste, and the beds loaded with organic pollutants are returned to the multi-reactor kiln for thermal treatment to obtain adsorption coal . 2. The method according to claim 1, characterized in that non-activated coal is used as the beds of the coarse filter to be passed first. 3. The method according to claim 2, characterized in that at least partially activated carbon is used as the beds of the fine filter following the coarse filter. 4. The method according to claim 1, characterized in that coal is used in the pelletized state as beds. 5. The method according to claim 1, characterized in that those with a proportion of polar substances are also used as fillings. 6. The method according to claim 5, characterized in that aluminum oxide and / or silicon oxide is used as polar substances. 7. The method according to claim 6, characterized in that aluminum oxide and / or silicon oxide-containing waste or waste water from the paper manufacturing is mixed. 8. The method according to claim 3, characterized in that the filters are guided in countercurrent to the loaded wastewater. 9. The method according to claim 3, characterized in that at least the fine filters are backwashed with process water before emptying the loaded adsorption coal. 10. The method according to claim 1, characterized in that the filtration system is filled with adsorption coal in continuous operation, then flowed through by garbage-laden wastewater, optionally freed of loaded adsorption carbon after backwashing, and after refilling with adsorption carbon is used again for filtration. 11. The method according to claim 3, characterized in that the filters are moved to improve the filtration effect such that a constant movement of the bulk material is brought about. 12. Multi-stage filtration device for performing the method according to claims 1 to 3 and 8 to 11, characterized in that a coarse filter (114) from at least partially sieve-shaped containers (120) is provided, in which adsorption carbon is contained, and that one located in front of it a rotating prefilter (142) filled with lumpy coal is provided, which is pivoted into the sewer and the individual filter elements (144) containing the coal bed can be separated. 13. Multi-stage filtration device according to claim 12, characterized in that the rotating prefilter (142) is a chain conveyor having a drip mechanism. 14. Multi-stage filtration device according to claim 12, 5 characterized in that it is used as a prefilter (142) and / or Fine filter (400) contains a circumferential, perforated, endless belt (402) which is loaded with adsorption carbon at spatially separated stations (420, 430, 440), through which the loaded waste water flows and from the dirt-laden adsorption carbon 10 is exempt. 15. Multi-stage filtration device according to claim 14, characterized in that the circulating belt in cross section in its flow area (420) V-shaped, in its loading area (440) V-shaped or flat and in its 15 nem discharge area (430) in an inclined or tilted position is guided flat on the drive elements (422). 16. Multi-stage filtration device according to claim 14 or 15, characterized in that the band has a surface structuring (412) to a strong movement 20 to prevent the bed of coal in the flow area (420). 17. Multi-stage filtration device according to claims 14 to 16, characterized in that a system of at least three arranged at an angle to each other and 25 separately guided, mutually operating individual belts (428, 426, 402) are provided, one of which (428) accepts fresh adsorption carbon and transfers it to the subsequent filtration belt (402), which carries the adsorption carbon loaded with dirt load onto the last belt (426) promoted 30 changes which belt (426) feeds the material back to the multiple reactor pile. 18. Multi-stage filtration device according to claim 12 or 13, characterized in that a rotating system on a guide (180) of tiltable, open-top kitchen 35 beln (182) is provided, the bottom wall (184) of the buckets, which contain the loose adsorption carbon (186), is perforated, and the guide (180) unloading the loaded adsorption carbon and reloading with fresh adsorption carbon by means of a tilting or deflection movement «Possible. 19. Multi-stage filtration device for performing the method according to claims 1 to 3 and 8 to 11, characterized in that a coarse filter (330) is provided, which is attached to a conveyor belt (332) and is open at the top. «Ne bucket (338), the wall (344) is perforated in the flow direction, and the bucket (338) contain adsorption carbon. 20. Multi-stage filtration device according to claim 9, characterized in that the bottom surface of the bucket (338) is so nubbed and, if necessary, the longitudinal direction contains subdivisions (350). 55