DE19520399C2 - Process and device for the treatment of waste water from wet dedusting from shredder systems - Google Patents

Description

The invention relates to a method and a device for processing Waste water from wet dedusting from shredder systems for the disposal of the foreign substances contained in the waste water.

These wastewater contain special ingredients such as broken glass and high proportions Fibers and lint, metal abrasion, paint particles, bitumen particles, rubber, art Material and foam particles as well as sand and street dirt.

Methods and devices developed by the applicant are known in which the wet foreign substances are separated from the others immediately after they have accumulated Shredder fractions are discharged. The foreign substances are in as sludge collected in a container, optionally fed to a drying section and disposed of as dried material.

In practice, it has been found disadvantageous that according to these procedures the water remaining in the plant was still very contaminated gene, with which the high requirements for relieving foreign substances Environment can no longer be met.

According to SU 1 028 604 A, an electroflotation device is known which is maintenance-intensive and too expensive to operate. That from this facility The process to be derived is therefore complicated and can produce waste water Do not clean wet dedusting from shredder systems without causing failures  is coming. In particular, the material contained in the wastewater would be the parts directions such as B. clog the sieve and the hydrocyclones after a short time.

The invention has for its object to a method and a device create that together through a qualitatively improved preparation an appropriate disposal of the waste water Ensure foreign substances, whereby well-known and proven sieve, hydro cyclone, flotation plants as a facility for a wet dedusting plant from Shredder systems are to be connected downstream.

According to the invention, this object is achieved by the following process steps:

• - Application of the waste water generated in a wet dedusting plant sers on a curved screen and feeding the separated foreign matter components to a collection container,
• - Forwarding of the wastewater treated in this way to a flotation plant Separation of other foreign substances according to the principle of Flotation and feeding of the floated and sedimented substances a collection container,
• - Return of the reusable wastewater with a dryer substance content of less than 1 g / l to the wet dedusting system via a Management,
• - Drainage of the foreign matter supplied to the collection container in one Device for producing a dewatered product with a Dry matter content of <55% and  
• - Return of another reusable wastewater from the Device via a line to the wet dedusting system.

According to the method of the invention, the ingredients are overlaid with few process steps so effectively cleaned that the dewatered Product has a dry matter content of <55% and the purified water can be reused in the cycle.

This is due to the discharge of the wastewater onto a curved sieve and the subsequent wastewater flotation reached. By using the bow Sieben a pumping of waste water can be omitted. The bow sieve is only attached below the wet dedusting system, and that Waste water flows into the sieve by gravity.

Further process features result from claims 2 and 3.

The device according to the invention for carrying out the method is connected downstream of a wet dedusting system from shredder systems and comprises

• - A curved screen, which is downstream of the wet dedusting system, wherein a collecting container is connected after the curved screen,
• - a flota based on the principle of flotation tion system with a subsequent collection container for the floatable and non-floatable substances with a device for drainage is connected and  
• - a line after the flotation plant to the wet dedusting plant and a line after the drainage device for wet dedusting investment.

With the features according to claims 5 and 6, the device is closer Are defined.

These simple measures make it possible to build a compact system to manufacture, which is easy to use and less prone to failure. Such The system can be easily added to existing shredder systems.

The invention thus advantageously allows energy and environmental awareness Treatment of such waste water with disposal of the foreign substances, which cost is inexpensive to use.

The drawing shows a schematically represented device configuration, with who can carry out the procedure.

The invention is explained in the structure of a device with subsequent explanations tion of the process flow shown.

The device consists essentially of a sieve 2 downstream of a wet dedusting plant 1 , a hydrocyclone 3 , a flotation plant 4 and a dewatering device 7. The sieve 2 is assigned a collecting container 5 . With an appropriate composition of the wastewater, it may be useful to also provide a line (not shown) from the sieve 2 for the removal of foreign substances to the collecting container 6 .

The hydrocyclone 3 and the flotation system 4 are connected to a further collecting container 6 . The collection container 6 is assigned to the drainage device 7 , which is preferably designed as a press.

Between the wet dedusting plant 1 via the sieve 2 and the hydrocyclone 3 and the flotation plant 4 , a main circuit with the line 8 for the waste water is formed according to the invention.

The hydrocyclone 3 , the flotation system 4 and the collecting container 6 have a connection to the dewatering device 7 which is essential for the invention. A second circuit with line 9 between the dewatering device 7 and the wet dedusting system 1 is provided, the main circuit with line 8 and the second circuit with line 9 being a functional unit for an essentially coherent, closed circuit for the waste water.

The process flow according to the invention provides that first in the wet dedusting plant 1 waste water in a curved screen 2 for separating the relatively coarse components, such as. B. fibers and lint, and then the separated components are fed to a collecting container 5 . At the beginning of the process steps, the curved screen 2 is used as a dynamic dewatering and classifying screen without mechanically moving parts for a process-influencing start effect in order to determine the efficiency of the entire process from the start. From a water discharge ( not shown) of the curved screen 2 , the waste water treated in this way is fed to the hydrocyclone 3 for the separation of fine, sedimentable foreign matter, while the foreign matter load is reduced by up to 60% of the foreign matter contained.

Subsequently, the separated constituents arrive as a slurry in a collecting container 6. This effect of reducing the foreign substance load by up to 60% advantageously combines the effect of the first, above-described method step in curved sieve 2 , where the fiber / lint-like constituents have already been removed. The wastewater that has been freed of foreign matter is fed to a flotation plant 4 . In this, the separation of further foreign substances is carried out according to the principle of flotation, according to which the foreign material load is completely minimized. Parts of the foreign matter are carried by the flotation to the surface of the wastewater level and from there to the collecting tank 6 as foam. The non-floatable components sink, these are drawn off and fed to the collecting tank 6 as sludge, the cleaned waste water having a dry substance content of less than 1 g / l being returned to the wet dedusting system 1 in the main circuit of a line 8 . This result surprisingly results from the combination effect described above, since this value cannot be achieved by conventional flotation due to the chemically and physically different foreign substances in the waste water. Thus, these process steps culminate in a new effect, namely the reduction of the dry matter content in the wastewater to less than 1 g / l, and a significant reduction in hydrocarbons.

Only due to this treatment does the further process step enable the foreign substances, which are also deposited and located in the collecting container 6, in the z. B. dewater press 7 so that a dewatered product 10 with a relatively high dry matter content of <55% TS, yes even proven in experiments to almost 80% TS can be produced. Products of this type can be disposed of directly without further after-treatment and comply with the legal regulations. The process sequence according to the invention then closes by the z. B. Press 7 resulting waste water is fed to the second circuit of a line 9 and in turn the wet dedusting system 1 .

Practically, it has been shown that a hydro cyclone 3 can be efficient in the course of these process steps if a high load of relatively light but sedimentable foreign substances is contained in the waste water. For the functional context of the invention, the interposition of a hydrocyclone 3 can be dispensed with.

It is also possible to separate further foreign substances after the flotation.

In addition, under certain circumstances to increase the Aufb degree of readiness for at least one of the sedimentation and / or flocculants are added.

The functional unit of the essentially coherent, relatively abge closed circuits thus allow energy-saving, environmentally friendly Wastewater treatment using generic methods when generating a Product, which is a disposal in terms of its dry matter content in the sense of the legal regulations and possibly also a thermal Recovery enables.

Reference list

1

Wet dedusting system

2nd

Sieve

3rd

Hydrocyclone

4th

Flotation plant

5

Collection container

6

Collection container

7

Drainage device, press

8th

Line, main circuit

9

Pipe, second circuit

10th

dehydrated product

Claims (6)

1. Process for the treatment of waste water from wet dedusting from shredder plants with the following process steps:

• a) loading the wastewater accumulating in a wet dedusting system ( 1 ) onto a curved screen ( 2 ) and feeding the separated foreign matter components to a collecting container ( 5 ),
• b) forwarding of the wastewater treated in this way to a flotation plant ( 4 ) for separating further foreign substances according to the principle of flotation and feeding the flotated and sedimented substances to a collecting tank ( 6 ),
• c) returning the reusable wastewater with a dry matter content of less than 1 g / l to the wet dedusting system ( 1 ) via a line ( 8 ),
• d) dewatering the foreign matter supplied to the collecting container ( 6 ) in a device ( 7 ) for producing a dewatered product ( 10 ) with a dry matter content of <55% and
• e) returning a further reusable wastewater from the device ( 7 ) via a line ( 9 ) to the wet dedusting system ( 1 ).

2. The method according to claim 1, characterized in that a drainage product ( 10 ) is produced with a dry matter content of almost 80% TS. 3. The method according to any one of claims 1 or 2, characterized in that that to increase the degree of preparation at least one of the proced steps sedimentation and / or flocculants are added. 4. Device for performing the method, which is connected downstream of a wet dedusting system of shredder systems

• a) a curved sieve ( 2 ) which is arranged downstream of the wet dedusting system, a collecting container ( 5 ) following the curved sieve ( 2 ),
• b) a working according to the principle of flotation flotation system ( 4 ) with a subsequent collection container ( 6 ) for the floatable and non-floatable substances, which is connected to a device for drainage ( 7 ) and
• c) a line ( 8 ) after the flotation system ( 4 ) to the wet dedusting system ( 1 ) and a line ( 9 ) after the drainage device ( 7 ) to the wet dedusting system ( 1 ).

5. Device according to claim 4, characterized in that the sheet sieve ( 2 ) has a line for the removal of foreign matter to the container container ( 6 ). 6. Device according to claim 4 or 5, characterized in that the drainage device ( 7 ) is a press.