WO2008083703A1

WO2008083703A1 - Method for drying solid and/or liquid waste materials

Info

Publication number: WO2008083703A1
Application number: PCT/EP2006/070243
Authority: WO
Inventors: Jochen Zingelmann
Original assignee: Jochen Zingelmann
Priority date: 2006-12-28
Filing date: 2006-12-28
Publication date: 2008-07-17

Abstract

The invention relates to a method for drying solid and/or liquid waste materials, especially for the treatment and use of waste materials, whereby the quantity and humidity of the waste materials to be dried are determined. The quantity of heat required to dry the waste materials until they reach a pre-defined residual humidity is calculated from said determined values. A drying installation for drying the quantity of waste materials is controlled according to the calculated quantity of heat.

Description

Process for drying solid and / or liquid waste

The invention relates to a method for drying solid and / or liquid waste, which method can be used in particular in the treatment and recycling of waste

DE-A-103 46 892, EP-A-I 434 003 and US-A-2004/0134395 disclose processes and devices for the treatment of solid and liquid waste and waste mixtures. In these known methods and devices, the wastes are dried, inter alia,

The object of the invention is the drying process of solid and / or liquid Abfa I is open, as they occur in particular during the treatment and utilization ^¬ optimize.

To solve this problem, the invention proposes a method for drying solid and / or liquid wastes, especially in the treatment and utilization of waste materials, wherein in the method, the amount and moisture of the waste to be dried are determined from These determined values, the amount of heat is determined, which is required to dry the waste to below a predetermined residual moisture, and according to the determined amount of heat, a drying plant for drying the amount of waste is controlled.

According to the invention, therefore, the amount and moisture of the waste to be dried is determined and the drying plant controlled so that the waste to be dried leave the drying plant with a predetermined or predetermined residual moisture. For this purpose it is necessary according to the invention. deriving from the determined values for the amount and the moisture of the waste to be dried, the amount of heat (eg the temperature and / or amount, ie throughput of drying air) required for the drying of the waste, depending on the required heat amount then the drying plant is controlled to dry the amount of waste.

In an advantageous development of the invention, the drying plant operates in continuous operation, so that the amount of waste material fed in per unit time and its moisture are determined. The control of the drying aπlage takes place in such a way that such an amount of heat is supplied or such an amount of heat acts on the waste in the drying plant that the output of the drying plant amount of waste has the maximum allowable residual moisture level.

The drying process of the waste can be optimized by circulating or otherwise agitating the waste within the drying plant, thus increasing the surface area of the waste within the drying plant, thus making the removal of moisture from the waste more effective.

The determination of the amount and the moisture of the waste to be dried is preferably carried out without contact.

In a further advantageous embodiment of the invention, the drying of the waste material takes place within the drying plant by drying air. This drying air expediently flows opposite and / or transversely and / or at an angle therebetween to the transport direction of the waste to be dried within the drying plant.

The drying plant used is preferably a rotary drum drying plant which has internals which, on the one hand, store the waste Fabrics through the rotary drum! transport and on the other hand keep the Abfailstoffe within the rotary drum in motion, in particular circulation movement. The internals are expediently a web which protrudes helically in the manner of a screw conveyor from the inside of the rotary drum.

In an advantageous embodiment of the invention, it is further provided that the amount of heat required for drying the amount of Abfaüstoffen is controlled by the flow rate and / or temperature of drying air and / or the Verweiizeit the amount of waste to be dried in the drying plant.

The erfiπdungsgemäße method may be integrated in a control and / or in a control unit of the drying plant. In the latter case, the residual moisture content of the amount leaving the drying plant dried solids is determined and optionally fed via a control loop with the difference between the desired maximum residual moisture content (target residual moisture) and measured (actual) residual moisture and thus as a reference variable a controller.

With the drying method according to the invention can be in the treatment and recycling of waste materials, as described in the above-mentioned writings, especially dry after appropriate sorting and preprocessing organic waste prior to their Kompak- drying in the second drying stage. The gasification of these dried in the manner according to the invention and then compacted organic Abfailstoffe for the production of coke is more advantageous

Development of the invention associated with the production of activated carbon by the compacted waste materials are gasified to form gas, ash and coke in a gasification reactor, the coke and the ash are separated and the coke is further processed to activated carbon. It is expedient here if the separation of coke and ash takes place via a screening device in or at the discharge of the gasification reactor. For the production of activated carbon from the coke only the crushing of the coke is required if the activated carbon is to be in the form of bulk material.

The invention will be described below with reference to a method described by way of example or, provided for carrying out this method device for the treatment of solid and / or liquid Abfaiistoffen, in connection with the drawing, in which

1 is a block diagram showing the individual process and Anlagenkompo ^¬ nents a method for substantially complete recovery of domestic and commercial waste and / or liquid predominantly organic waste,

Fig. 2 is a schematic representation of a Durchiauf-drying plant with rotary drum and

Fig. 3 is a schematic representation of a gasification reactor with separate discharge of ash and coke.

The method described here by way of example for the complete recovery of household and commercial waste and / or liquid predominantly organic waste consists of process sections, each of which has a modular structure and thereby makes it possible to adapt to different flow rates (see the general procedure in FIG. 1), Due to the modular design, it is possible to operate the energetic stage also locally detached from the rest of the system and so to take advantage of decentralized power generation, peculiarities of the process are the drying (pre- and post-drying) and the production of coke for use as activated carbon . 1st Process Section: Pretreatment and Sorting

Obtaining visually and manually detectable parts that are selected by pre-sorting manually and / or semi-automatically and / or automatically according to material groups, such as metal, glass, plastic, paper, cardboard, cardboard and / or composites of mixtures of these and other raw materials. To stabilize the flow of material, the material is fed to a silo after coarse crushing and iron deposition, which (for example with a puller) metered the material continuously into the further treatment. To facilitate sorting work, the material stream to be treated is transferred to a drying drum 10.

This drum 10 consists of a metal tube with process-specific internals 12 (screw conveyor), which are able to transport the material in the longitudinal direction 14, while the metal pipe rotates about its longitudinal axis in a defined direction. In the opposite direction 16 to the Materialfiuss 14 10 hot air 18 is blown into the drum, which extracts the material in the drum 10 water and easily volatiles. The control of the drying process is carried out by:

1, non-contact measurement of moisture and Massenbestimrnung of the feed material, taking from the measured values

2. the air temperature and air quantity for the drying process and

3. the resulting residence time in the dryer is calculated, whereby the retention time by

4. Control of the speed of the drum is calculated.

The laden with water vapor, dust and volatile substances exhaust air 20 is fed to a (not shown in Fig. 2) biofilter and cleaned there (Description Section 5 - ancillary facilities). The dried material falls from the drying drum 10 via a chute 22 in the subsequent TrommeSsieb or on a conveyor belt 24, a slat curtain 26 o.dgi. Closure system prevents escape of hot air from the discharge end 28 of the dry drum 10.

After the pre-drying of the waste materials to a maximum permissible residual ^¬ moisture, fractionation of the dried waste material takes place, this end, a drum of an inner defined perforated drum which is continuously rotated about its longitudinal axis, and an outer closed-Senen drum, in which The sieved fine fraction falls into it and is transported out in the longitudinal direction with a conveyor belt. The dust generated in the drum is sucked off and the exhaust air is cleaned via the biofilter. Other screening methods and devices may also be used.

Via a cross conveyor, which must be adapted to the specific location, the fine fraction is fed directly to the treatment.

The coarse fraction is, as far as possible dried and thus also deodorized and freed from the mineral and small parts, then transferred to the sorting belt.

For this purpose, e.g. an inclined conveyor with webs transverse to the direction on the belt.

The sorting process is carried out in steps, housed in one or more overhead cabins, manually and / or with automated systems,

The material is transported through the sorting cabs with conveyor belts.

The different material groups are thrown off into separate shafts and recorded in, in particular, the same-level collection systems and neither as bulk material, loose, or as pressed bales fed to traditional recycling.

2nd Process Section: Processing

The non-sorted material is pre-shredded electro-mechanically in the further process sequence with a single and / or multi-shaft crushing system and at the same time freed by a particular multi-stage separation of metallic components.

By e.g. a Überbaπdmagneten are the ferrous metals and deposited with a Wirbelstromabscheider the non-ferrous metals.

The metallic constituents are separated from the process separately for ferrous and non-ferrous metals and recycled, as described under no. 1 described supplied.

In a drying drum, e.g. under no. 1 described and shown in Fig, 2, the material is removed from the residual moisture. Other drying methods can also be used.

The air heating takes place via heat exchangers against hot water, which was obtained by heat extraction from the exhaust gas of the engines.

The exhaust air is the under. 1 named biofilter supplied.

About a slide the dried material is fed to a further screening. This second screening stage can be identical to that under no. 1 and differs only in the mesh size of the screen, which is about 50% of the first in this second screening stage. The fine fraction, which is composed essentially of mineral constituents, is supplied to a flotation in this process section.

The transverse transport of the fine fraction to the flotation is provided by belts.

The flotation (see, for example, Figures 3 and 4 with associated description in DE-A-103 46 892) consists of a tub of stainless steel with sloping bottom, at regular intervals nozzles with defined spray characteristics are incorporated in the bottom, by the compressed air for swirling which is directed to the masses to be floated.

Above the ground water is up to the upper edge of a gutter, which is located at the opposite end to the material entry.

The material entry is made from the side where the floor is highest.

Due to the slope of the soil, the injected compressed air and the supplied water at the end of the task, a flow of material to the bottom of the soil. In a gutter, the sandy-gravelly material collects and is transported with a snail to one side. Here, the purified mineral fraction is conveyed through a second screw with sieve bottom from the plant and drained. It can be used as a building material.

The flooded organic material collects in the gutter. It is discharged through a sieve belt and fed directly to the compaction.

The water from the gutter and the drainage water from the sieve are fed to the central water treatment (see point 5 - ancillary equipment). The remaining material in the stream consists predominantly of organic substances, they are fed to a process-specific equipped conveyor belt a homogenizing and Kompaktiereinheit.

During this transport, the moisture content of the material is determined by means of a non-contact measuring method, and the throughput quantity is determined using a belt scale. By metering high-waste water, e.g. Sewage sludge and / or other sludge, which is controlled by a process computer, the adjustment of the material to the process-specific moisture required, The admixture of the sludge via a controlled via the water content dosing, which extracts the material to be conveyed from a silo.

The loss of water during compaction is taken into account empirically during dosing. As a result, this process achieves a defined moisture content for the briquettes to be produced.

Depending on the required capacity, parallel systems are used for homogenization and compaction (modular design).

Via a distributor belt, which transports at right angles to the plants, the material is fed to the feed chutes of the compacting plants. A scraper above the belt, controlled by a filling level indicator in the loading shaft, directs the material via a chute directly into the respective feed chute of the compacting plant.

The compacting machines operate on the principle of a twin-screw extruder and are equipped with process-specific tuned shafts, which homogeneously mix and compact the material. During this process, the estate heats up to over 150 ° C. Thus, the material is sanitized, homogenized and solidified in itself. The briquettes are protected against the weather and very storable. They are biologically inactive and odorless! ,

The forming of the briquette to be produced via a process-specific designed fitting at the mouth of Kompaktieranlage. The material strands emerging in this way are guided behind the fitting over a cooling section and, after hardening, cut to length mechanically and / or in an automatic process.

The properties of the briquettes correspond to the process-specific requirements for the following gasification process.

3rd Process Section: Gasification

In the third stage of the process, the briquettes are converted into an energetically or chemically usable, tar-free gas which is suitable both for cogeneration plants with gas engines and / or for fuel cells with specific catalysts or can be used as synthesis gas.

The gasification reactor used is a fixed-bed shaft gasifier. It is a descending gasification with low negative pressure in the range of about 100 to 300 mm Ws.

The briquettes are transported via a conveyor (trough chain conveyor, chain scraper, etc.) onto the conveyor belt and from there via a controlled scraper device to a vibrating chute, which leads directly into the lock of the carburettor. The lock conveys the briquettes into the reactor, thereby ensuring the upper closure of the reactor, via openings in the upper reactor area, some of which lead to the interior of the reactor, and steam injection units. into the gasification zone, the necessary oxygen is introduced into the process.

For this purpose, a process-specific mixture of air and / or oxygen and / or steam, which is tailored to the gasification substance, is used. The

Control of the amount of air and / or steam as well as the input by means of

Messfühiern that defined in the carburetor and / or in the gas cleaning at

Are introduced and various parameters such as pressure, temperature,

Measure mass flows, fill levels, temperature in the reactor and the chemical composition of the resulting gas.

The required steam is generated in the inner shell around the reactor core. Water is introduced into the jacket from the outside and from the bottom, which spontaneously evaporates due to the high temperature of the inner jacket (about 500 ^° C.) and becomes superheated steam, which is then passed via pipes directly into the lower part of the gasification zone.

Through the upper part of the gasifier, air and / or oxygen are also conducted to the center of the gasification zone through a pipe with a distributor device at the lower end. This achieves the most uniform possible temperature distribution in the gasification zone.

Air is introduced into the lower part of the carburetor core via a second series of air nozzles in order to melt off the lower part of the resulting coke bed by oxidation / gasification. The material in the lower end of the carburetor rests on a conical part, which is closed at the bottom by a grate that is shaking and / or rotatable and thus allows the discharge of the ashes in the underlying collecting container.

Alternatively, the resulting coke can be drawn off via a chamber cooled with water on a steel conveyor belt through an altered lower part of the gasifier and then cooled by a lock from the gasifier. borrow. The separation of the ash from the coke is carried out via a vibrating sieve, the discharge of the ash via a screw with lock. The coke can be used as activated coke.

The bottom of the container is conical, so that the ashes can be discharged via a screw with rotary valve.

The gas which is formed in the reactor, after it has passed through the whole, glowing coke bed, to promote the lower end of the ceramic ausgemau- Erten reactor core around laterally over a pipe from the reactor hinausbe ^¬.

An integral part of the system is a rapid cooling of the gas in a cooler and an intensive gas scrubbing with subsequent drying, which releases a gas that meets the process-specific requirements of gas utilization.

The cooling and washing water from this process is purified and recirculated via a central water treatment plant adapted to the requirements of the process.

The resulting contaminants from the water treatment are separated mechanically and / or automatically and the gasification material prior to the compacting, as described in sec. 2 described, fed again,

In a process-specific tuned gas control system, the gas is mixed with air in order to arrive at an optimized gas mixture for the chemical process in the energy recovery plant.

A gasification reactor 30, as it can be used, for example, for the gasification of the compacted organic waste, is shown in FIG. 3. shown in a nutshell. The individual elements of the gasification reactor 30, as shown in FIG. 3, include:

31 Fluid supply 32 Sluice for the input material

33 Upper part of the carburetor

34 Central, Verteslereinrichtung for gasification

35 regulated feed for gasification agent

36 Controlled supply for gasifying agent for the outer nozzle ring 37 regulated supply of water or water vapor in the carburetor

38 gas extraction

39 evaporation zone for water

40 jacket of the evaporation zone

41 ceramic lining 42 reactor space

43 perforated shaft for coke discharge

44 controlled slide to control the Koksausieitung

45 Siebaπlage for separating the ashes from the coke

46 Ash discharge opening (with subsequent cherry pickle) 47 Coke discharge (for further processing as activated carbon)

The peculiarity of the gasification reactor 30 shown in FIG. 3 is that the resulting coke, located in the lower part of the gasification reactor 30 and in particular in the coking outflow shaft 43 above the controlled spool 44 (when it is closed), selectively via the discharge with Siebaniage 45 can dissipate. Here, it is no longer a burning of coke, but a separation of the coke from the ashes. The coke remains above the sieve 45 in the discharge of the reactor 30, while the ash falls through the sieve through down and is discharged through the Aschenaustragsöffnung 46. During the gasification of the compacted briquettes, which consist essentially exclusively of organic waste materials, the coke is thus carried out separately in the gasification reactor 30, for further processing for the purpose of producing activated carbon. Finally, the coke already forms the activated carbon and only has to be processed in order to have the activated carbon in the desired form (for example, a bulk material). In the case of activated carbon in the form of bulk material, there is a comminution of the coke, which can be done in a nachgeschaiteten crushing plant.

4th Process Section: Energy Generation

In the fourth stage of the process, the gas is used for energy.

The energetic utilization can take place in three different ways:

- Direct combustion of the gas via a process-specific equipped burner, with subsequent use of the combustion heat, combustion of the gas in a process-specific equipped gas engine with generator to generate electricity and use of waste heat from engine and exhaust gas through process-specific heat exchanger and - oxidation of the oxidizable components of the gas in one Process-specifically designed, catalytic process in a fuel cell, with suitable catalysts, and use of waste heat from the exhaust air of the fuel cell via process-specific heat exchanger.

5. ancillary facilities

Water treatment (WAB)

The polluted water produced in the process is transported to a central water treatment (see eg FIGS. 5 to 9 with the associated description in DE-A-103 46 892). The WAB consists of a container of approx. 3.0 m in height which is specifically adapted to the project and subdivided into various chambers, each of which is equipped with process-specific adapted devices, resulting in a quasi-modulatory structure.

The dividing walls between the individual modules have a nozzle of 0 100 mm in each case at a distance of 0.5 m and 1.5 m from the lower edge in the middle for attaching 100 mm PVC pipe or similar materials for the different process-specific discharges.

The plant is an open-topped container, which is preferably made of stainless steel, on the upper side walkable covered with grates and accessible by laterally welded steps,

For fall protection, a plug-in turntable is available.

The different chambers consist in detail of the following segments:

Inlet chamber, into which the waste water is pumped, with measuring station for the process-specific parameters required

Settling chamber into which the water from the inlet chamber directly flows via the lower pipe socket, for sedimenting substances, such as sands and other mineral constituents,

Light-weight separator (LSA) with an inlet above the upper pipe socket to which a coalescence separator is attached.

The separator consists of a PVC tube filled with a stainless steel wire mesh rolled up from a flat sheet. (Sketch 4, Fig. A) On the large surface of this fabric, the small dispersed droplets of light contained in the wastewater settle and combine into large drops, which can then be separated by their buoyancy.

The outlet from the LSA takes place via the upper nozzle on which a PVC sheet, 90 °, is placed and connected to a pipe approx. 1.0 m long, pointing downwards (Diagram 4 Fig. B).

The unused inlet and outlet are closed by caps. The series connection of two such separators can reduce light materials below a concentration of significantly <5.0 mg / l.

Mixing and dosing chamber containing a stirrer and dosing to free water by the added precipitation and flocculation aids of suspended solids and a number of solutes.

The inlet is brought to a medium height. The overflow passes through the upper spigot into a settling chamber as described above.

After the passage of two settling chambers the water is usable again,

The hot water should be pre-filtered e.g. take place over a gravel pit.

Biofilter - exhaust air purification

The exhaust air produced at different points in the system is laden with dust, volatile organic and inorganic substances.

The biofilter has to fulfill several functions: Adsorption of the entrained dust, Adsorption and metabolism of organic, partially odorous substances and inorganic odorous substances, regulation of the water content of the exhaust air.

The biofilter is a cuboid container of approx. 600 x 250 x 250 cm, corresponding to a 20 "sea container, with two tight-fitting doors at one head end.

Grates are installed in the container at a distance of 50 cm, thus enabling the multi-stage flow of air through the different floors of the fighter (minima! 4-fold cleaning).

At the bottom of the container, the condensation collects and is pumped to the WAB.

In various methods, there is a Feuchtigkeitsmangei. In this case, nozzles are attached to the roof of the container, through which water can be sprayed into the container together with nutrients.

As a carrier for microbiology, e.g. Oat straw, dried heather and / or other structurant material.

The microbiology is applied as a dispersion. The exhaust air flows through the filter from a lower corner to the diametrically opposite upper corner.

It should still be followed by an AK-Füter.

Claims

1. A method for drying solid and / or liquid Abfai Istoffen, in particular in the treatment and recycling of waste materials, in which the amount and moisture of the waste to be dried are determined, from these determined values, the amount of heat is determined, which is used to dry the Waste material is required to below a predetermined residual moisture, and according to the determined amount of heat, a drying plant for drying the amount of Abfailstoffen is controlled.

2. The method according to claim 1, characterized in that the determination of the amount and / or the moisture of the waste to be dried is carried out without contact.

3. The method according to claim 1 or 2, characterized in that the drying plant operates in continuous operation and that the amount of waste per unit time, i. the rate at which the drying plant to be dried waste is supplied, is determined.

4. The method according to any one of claims 1 to 3, characterized in that the waste to be dried circulated in the drying plant or the like. to increase the surface of the waste is set in motion.

5. The method according to any one of claims 1 to 4, characterized in that in the drying plant, a drying air flow is generated, which is directed opposite and / or transversely and / or at an intermediate angle to the transport direction of the waste to be dried.

6. The method according to any one of claims 1 to 5, characterized in that the Trocknungsaπlage has a rotary drum with internals for transport and thereby successful movement of the waste to be dried.

7 ^' . Method according to one of claims 1 to 6, characterized in that the amount of heat required to dry the amount of AbfaUstoffen is controlled by the flow rate and / or temperature of drying air and / or the residence time of the amount of waste to be dried in the drying plant.

8. The method according to any one of claims 1 to 7, characterized in that the residual moisture of the amount of dried AbfaUstoffen is determined and the determined value of a control and / or regulating unit of the drying plant is supplied.

9, Method according to one of claims 1 to 8, characterized in that the amount of heat is controlled by the amount and / or the temperature of drying air.