SE455304B - PROCEDURE AND INSTALLATION FOR DRAINAGE OF WATER-LAKING SLACKS - Google Patents

Description

455 304 2 The paint sludge is subject to the law on so-called special waste, which must be disposed of in a special way regulated by legislation. The costs of such care are considerable. As the paint sludge also has a water content of 65 to 70% by weight, approximately 2/3 of the costs for disposal relate only to the water content.

At smaller plants, attempts have already been made to integrate a centrifuge into the aforementioned water circulation system. In this case, through a pump, water and lacquer coagulate are continuously sucked off from the bottom of the wet separator basin and carried to a thickener, e.g. a hydrocyclone, in which some sludge-water mixture is separated from the water. In connection with this, this varnish is centrifuged to separate the embankment and taco coagulate. This method has not proved suitable for use in large spray booths. Such large plants, which are mainly used in the automotive industry, have paint sludge scrapers, which extract aqueous paint coagulate, ie paint sludge.

The object of the invention is to understand a method and a plant of a suitable type, which enables a far-reaching dewatering of the lacquer coagulate.

This object is solved by a suitable method with features according to the characterizing part of claim 1.

In a plant according to the preamble of claim 5, this problem is solved by the devices specified in from the wet scavenger basin paint sludge is removed with a water content of about 65 to 70% by weight and mixed under water addition to a paint sludge suspension in a mixing container in which the paint particles are located. in a floating state.

The suspension is passed to a centrifuge, in which the lay particles are separated from the water. The water is returned to the wet separator basin, while the largely dewatered lacquer coagulate with a water content of only about 50% by weight is now taken out of the centrifuge drum by means of a scraper device and can in this condition with significantly reduced water content be taken to proper disposal. a lower cost. characteristic part of the requirement. 50 455 304 3 Further advantages and features of the invention are set forth in the subclaims and in connection with the invention, an exemplary embodiment of the following description.

R1tn1ngarna v1sar: F1qor 1 en schemat1sk sk1ss av en plantn1ng according to the invention, Ftgur 2 a vert1kalt sn1tt through a, 1 anJäggn1ngen according to the invention, use centr1Fug.

Below a spray cable 1 for varnishing of example v1s b1lar 1 b1l1ndutr1n, a so-called wet trap basin 2 is placed. In this wet scavenger basin 2, the amount of lacquer sprayed on the present btlen, the so-called over-spray, is precipitated and coagulated. For precipitation and coagulation, conventional reactants such as lacquer adhesives, anticoagulants or coagulants are usually used. This is usually used as baking soda. Due to this sodium hydroxide solution, the resins in the water-separated lacquer beads are saponified to a large extent, so that they become less sticky, ie they do not peel off. By decoupling, the tendency of the paint partitions to reduce slag on the plant's walls and other building elements is reduced. The removal and final storage of the lacquer stem also becomes easier when it consists of a non-stick lacquer coagulate. When using the 1-day chemical curing varnishes, in particular the so-called 2-component varnishes, a particularly anti-caking coagulant tone is obtained by using the alkaline agent as an additive. For this purpose, a mixed water is preferably used, supplemented by water-containing wax dispersion of montan wax and paraffin water. The details can be found in German Patent Specification 2,758,873 (corresponding to British Patent Specification 2 Û11 371). During this treatment, the Jackpart1ktarna coming to the water are connected immediately, whereby an agglomeration of the initially still color-changing color particles is changed. The wax does not itself participate in the decoupling process (the doubling process); it always provides the large surface area required for the attack of the alkaline agents and enables a fast and complete decomposition process. The wax consumption is small, as the predominant part in which sludge deposited in the flocculating lacquer coagulate again consumes the water.

At the bottom 5 duty The moisture scavenging basin 2 deposited lacquer sludge 4 is removed from the moisture scavenging basin by means of a lacquer sludge scraper 5. This lacquer sludge scraper consists of an endless belt 6, for example an endless chain, which at its end is provided with step-like pre-slats 7. over It tlll an over the water surface 10 beïntntltgt breaking claws 8. for the roof sludge 4 over an inclined surface 9 avglvnlngshudde 11.

From this discharge head 11, the strong aqueous tank is conveyed to a combustion container 12, which is provided with a stirrer 13. In the mixing tank 12, a pipe 14 coming from the wet trap basin 2 opens, in the case of a shut-off valve. This pipeline 14 is connected to the wet trap basin 2 just below the water surface 10 and clearly indicates the paint sludge 4 located at the bottom 5 over this pipeline 14. The mixing tank 12 is supplied with so much water from the wet trap basin 12 that with a stirrer 13 a paint trap suspension can be prepared, | which also the coagulated lacquer stock is fnfördelal 1 water. The paint sludge suspension produced in the mixing container 12 is conveyed, by means of a pump 30 over a pipeline via a separate section of solid substance. The purified and also paint coagulum water is passed 16, eP central joint 17, | happens. large extension to ie lacquer coagulate from water again the wet scavenger basin 2 over a return line 18. The dewatered lacquer sludge, ie this large extension of water-free lacquer coagulate trolley 20. 19 is left | A transport structure under the center joint 17 Structure and method of operation For the center joint 17 is shown in Fig. 2. A housing 21 is hard pressed, in which a drum 22 is arranged. Pipeline 16 For the supply of the sludge sludge suspension stone, the drum opens at the bottom. Arranged in the drum is a scraper device 25, which on its inner drum wall 24 is provided with scrapers 25, of a type called scraper clamps. These draw suction at a distance of a few tenths of a millimeter from the inner drum wall. The scraper device 23 is inextricably mounted on a 50. 455 304 26. The housing 22 is thus coupled to the drive wax 26 over a four-wheel drive arrangement of the drive wax (27). Vtd forward drsft over the main drive motor 28 is driven following the scraper device 23 and the drum 22 at the same speed.

On the other hand, when the drive shaft 26 is driven in the opposite direction by a smaller drive motor 29 for the scraper device 23, then only the scraper device 23 is driven, while the drive 22 of the drum 22 over the wheel drive device 27 is not driven. The drum 22 is held in place with a 1 nntnxngen: nte vtsad, usually backlash barrier, so that the Scraper 27 moves sxg along the xnre drum wall 24.

On the surface of the drum 22 a ridge 51 thus associated with it is thus arranged. A so-called shell pipe 22 opens into the vent canal 22 and is connected to the return line 18. At the upper end of the drum 22 facing the above contact, outlet valves 33 are arranged secondarily, which wind up ball valves 35 loaded from outside with prestressed pressure springs.

The procedure is as follows: The lacquer strain 4 carried by the lacquer sludge scraper 5 from the wet scavenger basin 2 into the mixing tank 12 exhibits a water content of from about 65 to 70% by weight of the common amount of water which is fed to g / l. This weight. In the btandnnngsbchållaren 12 from the wet separator basin 2 over the pipeline tü, the amount of the solid substance 1 the sludge sludge suspension, llgger 1 The solid substance, ie the paint lamp particles, absorbs suction through the centrifugal action on the inner drum wall 2ä. The purified water flows through a passage channel 36 nn in the from above the open duct 31, in which the further | the thus reddened dipped shell tube 32 is the rotating water one to bring txltbak to the wet scavenger basin 2. ter. When the inlet duct 51 is arranged stagnantly, a water pressure of about 0.5 bar is obtained, which is sufficient, the water over the return line 18 455 304 6 When the volume of the drum 22 is exhausted, the supply of the sludge sludge tone is stopped by shutting off the pump 30 and the drum 22 with the scraper device 23 operates a further tooth with a reduced speed. At this reduced speed, the valve ball 55 is pushed by the compression spring šh radnltt | something, so that the outlet valves 35 are opened. Through this it is thrown | the drum beftntlxga the water out. The solid deposited on the drum wall 24 is thus dry-centrifuged. At the end of the reaction tone, the main drive motor 28 and the drive gear 26 are connected. opposite direction - in the manner described above - so that the scrapers 25, of the scraper type, scrape off the solid from the inner wall 24 of the drum.

The solid is taken out at the bottom of the center joint 17. The substantially dewatered tack coagulate 19 still achieves a water content of about 30% by weight.

The whole process can be easily controlled by a programmable controller. The central joint 17 is commercially available under the handwriting designations (WP5 40A-14 "or" WP5 40A-15 "of Turbo-Separalor AG, CH-6920 Ltchtenstetg, Switzerland).

Claims (3)

10 15 20 25 455 304 PATENT REQUIREMENTS Process for dewatering water-deposited lacquer coagulum deposited from water as aqueous leachate, wherein the lacquer sludge is taken out of the water, characterized in that some leachate removed from the water is added again. In connection with this, the lacquer sludge suspension is separated by centrifugation into water-cured water-poor lacquer coagulate. Process according to Claim 1, characterized in that the lacquer sludge suspension has a lacquer coagulant content of 6 to 10 g / l. Plant for carrying out the methods according to claims 1 and 2, consisting of a wet trap basin for water and of water and lacquer coagulum formed lacquer sludge which has been deposited, and a lime sludge scraper for discharging the deposited lacquer sludge from the wet trap basin, characterized in that the lacquer sludge scraper ) is followed by a mixing container (12), which is connected to the water present in the wet trap basin (2) for the preparation of a paint sludge suspension, and that the mixing container (12) is connected to a centrifuge for separating water and paint coagulate. Plant according to claim 3, the centrifuge of which has a rotatable drum, on the inner drum of which the lacquer coagulate is deposited, characterized in that the inner drum wall (QH) is provided with a scraper device rotatable relative to the drum (22).