DE19904903A1 - Safe disposal of heavy electrical equipment, especially transformers and capacitors containing PCBs, is facilitated by vacuum distillation, condensation, and chemical separation - Google Patents

Abstract

Equipment (24) including chlorinated hydrocarbon residues, is introduced into the chamber (1). It is evacuated to below 10 mbar, then filled with non-oxidizing gas to above 30 mbar. Heating follows, with no supply of flushing gas, maintaining pressures above 30 bar whilst controlling gas and vapor extraction. Equipment is raised to a given temperature, at a pressure suppressing boiling. Some vapors accelerate heating by condensing on colder parts inside the chamber. Other vapors are extracted and condensed. On reaching given temperature, pressure is reduced, to initiate boiling, liberating chlorinated hydrocarbons which are condensed in the absence of any flushing gas. Condensate is further processed, if appropriate destroying the PCBs. An Independent claim is included for plant carrying out the process. Preferred Features: Electrical equipment contains a full working complement of hydrocarbons. Heating is by thermal radiation, induction, conduction, vapor circulation or vapor condensation. It can be achieved by a flow of current through the connection terminals. Evaporation takes place at temperatures of 100 deg C-400 deg C under chamber pressures of 0.01 mbar- 400 mbar. Initial pressure is 400 mbar maximum, the temperature rising to 400 deg C maximum, chamber pressure being lowered to at most 0.1 mbar. Later parts of the processing train are described in detail, including precautions to prevent PCB emission. Condensate is treated with alkali metals to form halogen compounds, which are centrifuged-off

Description

The invention relates to a method for the disposal of electrical Large devices with at least largely closed housings the group of transformers and capacitors with hydro substances from the group PCB and PCB mixtures are filled by thermal recycling.

Such large devices are devices with large Amounts of hydrocarbons from the group PCB and PCB mix are filled and which also have at least one function-related Component from the group iron (steel housing, transformer core), Copper (transformer windings), insulating materials (paper, plastic fo lien), aluminum (capacitor winding), wood (spacers), isola gates, seals, dielectrics, soldering materials and other components contain. The gaps and pores of solids are all over Usually filled with the hydrocarbons and it prepares considerable Difficulty disposing of such devices that are no longer in a loose Random fill in baskets or the like can be thermally treated.  

As a rule, you have the hydrocarbons with the PCBs through the usual drain openings of the large devices emptied and these large devices disassembled into individual parts before thermal treatment and so on crushed as possible, creating large PCB-contaminated surfaces with came into contact with the ambient air, which absorbs PCB vapors.

It is difficult and, above all, time consuming, the masses of such large devices including the hydrocarbons as long as they are in their casing are completely heated to temperatures at which the hydrocarbons also evaporate completely and from the depth of the Crowds are driven out. At least you have such devices disassembled, usually also shredded, so that large surfaces for one Heat and mass exchange and thus for the expulsion of the To create hydrocarbons.

The PCB's are polychlorinated biphenyls or poly chlorobenzene with different numbers of chlorine atoms, for example as with 1 to 10 chlorine atoms, and up to 209 isomers, the chlorine is between about 19% and 71%. They are extremely toxic and have a carcinogenic effect. The admission is predominantly via the skin, but partly through the air we breathe through the lungs, and leads damage to the liver and nervous system and changes in the blood picture. PCBs accumulate in the adipose tissue. There is a burn to avoid as much as possible and can only at temperatures above 1200 ° C in an oxygen-rich atmosphere, otherwise the same toxic dioxins (Seveso poison) and furans are formed. Because of their high dielectric constants and their flame retardant effect and because of their good thermal conductivity they have been used for many years as cooling and insulating liquids and heat transfer oils in Trans formers and electrical capacitors used, some in pure Form, partly as additives to other oils (RÖMPP CHEMIE LEXIKON, Georg Thieme Verlag, Stuttgart-New York, Volume M-Pk, 1995, pages 3243 to 3245).

Worldwide there are still large quantities of such large electrical devices  always in use. In the meantime, however, in most countries the manufacture, use, storage and even transportation verbo Despite high combustion temperatures, there is still a risk of Recombination to toxins exist.

The type of disposal depends on the PCB concentration: At the PCB or other are a PCB content of more than 50 mg / kg Dispose of electrical devices using special procedures. Alone for Germany was or is the amount of hazardous waste for the years 1989 to 2000 300,000 tons of PCB waste, including highly contaminated Waste with 1 to 50% PCB 95,000 tons, of which 56,000 tons on Transformers and 17,000 tons on large capacitors are no longer required (RÖMPP LEXIKON UMWELT, Stuttgart-New York, 1993, pages 536 to 538).

Exemplary values are at

Transformers:
Nominal power: 630 kVA:
Dimensions:
Length: 1612 mm
Width: 882 mm
Height: 1413 mm,
Weight: 2020 kg
Oil quantity: 436 kg.

Capacitors:
a) Nominal power: 100 kVA:
Dimensions:
Length: 715 mm
Width: 250 mm
Height: 895 mm,
Weight: 70 kg
Oil quantity: 30.7 kg.
Composition: steel case: 10.8 kg
Insulation material: 0.8 kg
Paper: 16.4 kg
Aluminum: 9.9 kg
Copper: 1.4 kg
b) Nominal power: 3 kVA:
Dimensions:
Length: 190 mm
Width: 120 mm
Height: 100 mm,
Weight: 4.52 kg
Oil quantity: 2.10 kg.
Rest: steel case, insulation material, paper, aluminum, copper: 2.42 kg.

This should not set any upper limits be ben; but there are still a lot of bigger and heavier ones PCB-loaded transformers and capacitors in operation in the must be disposed of in the next few years.

Through the prospectus of NUKEM "PCB Service System 50 process", Imprint 2000 St 393, it is known, electrical equipment, therefore Detoxify PCB-contaminated transformers by PCB-containing oil replaced by a cleaning oil and the transformer "reclassified". This is done by circulating the cleaning oil, which is passed through a processor in which the cleaning oil from the PCB freed and the PCB is collected. The circulation continues a period of 6 to 12 months and possibly longer. This reference gives an impression of how long it takes for the PCB-containing Oil is released from the depths of the transformer mass.

From DE 44 15 093 A1 it is known to hollow bodies such as oil filters Motor vehicles and oil cans in uncrushed condition in a random Filling by a so-called VTR process (vacuum thermal recycling) rid of residual oils by distillation under vacuum, their amount can amount to 250 g per filter. It is spoken small parts. The processing of PCB-containing oils is not addressed.  

In the publication "Appropriate Technologies for the Treatment of Scheduled Wastes ", Summary, in Review Report No. 3, August 1996, are numerous disposal methods for materials containing PCBs described, including a thermal described as a PCS process Desorption process. Under the subheading "Irregular Larger Inert Solids "(irregular larger inert solids) are also PCB- Called capacitors because of their aluminum content and the Danger of hydrogen development must first be crushed, to be treated with sodium hydroxide afterwards. This process will referred to as the BCD method. Regarding thermal desorption process is indicated that this at temperatures below 600 ° C is carried out, but that the particle size by crushing must be reduced to less than 5 mm. Are in a list for that PCS process in a pilot plant temperatures from 450 to 800 ° C and indicated a treatment period of 1 to 3 hours.

From DE 42 31 405 A1 it is known how removed device parts Transformer cores after draining from pollutant or PCB hal insulating oils in an autoclave with continuous supply of inert Carrier gases with partial decomposition of the organic components outgas and collect the pollutants and at high temperatures to process further. As far as the application of negative pressure specified is only a protective measure to prevent the Leakage of oil vapors to the atmosphere. Treatment of the Device parts within their original housings are not described ben. However, the use of continuously supplied carrier gases leads that the insulating oils and pollutants from large amounts of gas are accompanied, so that not only extremely large condensation areas are required, but always in accordance with the corresponding Partial pressures large amounts of oil and pollutant vapors in the Exhaust gases remain so that these exhaust gases are further processed must, which is particularly pointed out.

EP 0 682 994 A1 describes a similar method with the same Disadvantages known after devices including transformers  Drain the insulating oil and with residual amounts of it under constant Delivery of inert carrier gas at pressures between 0.5 and 1 bar be outgassed. By choosing such a high pressure Carrier gas, the heating rate should be increased. Here too the large amounts of exhaust gas have to be further processed, for what Aerosol separators and activated carbon filters can be specified. But it is also not specified here that the devices together with their original Lichen housings are to be treated. That is why impossible because no carrier gas is passed through this housing that could absorb the components of the insulating oil.

From DE 44 37 345 A1 it is known PCB-contaminated porous work detoxify materials such as wall coverings and masonry "in situ" that one in the room or in a neighboring room to withdraw oxygen a torch ignites, possibly provides an afterburner and that far cleaned cleaned oxygen-poor exhaust gas several times in the circuit over the contaminated wall surfaces. With a combustion process remains however, a certain percentage of oxygen is necessarily left, but above all the non-condensable combustion products and not flammable accompanying gases such as nitrogen, especially if the Burners also supplied fuel gases such as the specified propane become. Here, too, the large amounts of exhaust gas have to be further processed what gas scrubbers and activated carbon filters are specified for in turn deliver products to be disposed of again.

EP 0 423 039 A1 distinguishes between a) disposal of crumbly substances such as soil, sand and rubble, which as pourable mass from the beginning in vacuum in rotary kilns be heated and detoxified, and b) non-crumbly general cargo that initially under atmospheric pressure with the circulation of an inert gas heated to the final temperature and then in a vacuum is detoxified. The wood and metal parts are specified as general cargo of transformers and windings of paper capacitors and aluminum foil. As far as transformers are specified, they should can be reassembled and used after detoxification, d. H. the  Transformers were dismantled before detoxification. For the detoxification of Transformer wood at 260 to 280 ° C is a period of 18 hours specified, for the detoxification of capacitor windings under Verkoh paper at 285 ° C for 67 hours.

During the heating phase, the steam will fall below the limit pressure curves of the respective pollutant components at accordingly high temperatures, only small amounts of these components evaporate. A further heating under inert gas can be done without exhausting the furnace atmosphere only take place up to the saturation limit in the inert gas; otherwise the pressure either rises to well above atmospheric pressure or the evaporation process comes to a standstill. The disposal Complete large devices with a larger proportion or the total amount of insulating oils is not described and with the known method also not possible. Even if a mixture of inert circulating gas and PCB vapors are fed to a capacitor, then this needs either extremely large condensation areas, or the exhaust gases get with impermissibly high levels of PCB in the atmosphere, and indeed then when a safety capacitor follows the main capacitor is switched. The times for the heating phase and add up for the vacuum suction phase, in which the evaporation of the pollutants below the vapor pressure curve (s) only really begins by boiling.

In all cases, it is difficult and time consuming to detoxify those Objects in all places and especially in the depth of their Structures for the complete outgassing at the given pressure necessary to heat the high evaporation temperatures, especially these structures are generally also poorly heat-conducting.

The invention is therefore based on the object of a method Specify the type described above, with the electrical large devices from the group of transformers and capacitors can be without the oil filling with the ambient air in Interaction can occur, and that the large devices are subsequently free of Hydrocarbons, especially of PCB's, disassembled and possibly one  Final recycling can be supplied.

In the method specified at the outset, the object is achieved according to the invention in that

• a) the large devices together with their housings and with at least part of the operational amounts of this hydrocarbon substances are introduced into a treatment chamber and that the Treatment chamber for removing the ambient air on one Evacuated pressure of less than 10 mbar and then with a non-oxidative gas flooded to a pressure above 30 mbar becomes,
• b) in the treatment chamber in a heating phase without the supply of Purge gas by controlling the extracted gas and steam quantities a pressure above 30 mbar is maintained until one predetermined temperature inside the large equipment is reached, the lies above those vapor pressure curves at which the Evaporate hydrocarbons by boiling, releasing them Vapors are made to be relatively inside the casing colder places to condense again to the heating process accelerate while the regulated suction hydro material vapors are condensed,
• c) the pressure in the treatment chamber after reaching the pre given temperature is lowered to a value below of said vapor pressure curves, and that
• d) the hydrocarbons are evaporated by boiling and are free of purge gas condensed and further processed, possibly destroying the PCB's become.

It is particularly advantageous if the treatment chamber is a Pressure sensor is assigned, the output of which is connected to a controller is, the output of which is in turn connected to a control valve, which in the suction line between the treatment chamber and the vacuum pump pe is arranged and through which the suction power of the vacuum pump according to a target value for the internal pressure of the treatment chamber is adjustable.  

It was surprisingly found that such unassembled large devices with part or preferably all of the oil filling in one correspondingly large treatment chamber from the entire oil filling can be exempted and disposed of. They are playing closed housing and full or partial oil filling a crucial role, namely always at the hottest places Half of the vapor pressure curves evaporate oils and on the relatively colder ones Condensate below the vapor pressure curves again, causing the heat transfer without contact with the ambient air considerably is intensified.

These oil vapors also initially do not get into the spaces between the large devices and the inner walls of the treatment chamber or the boiler. These relationships are explained in detail in the detailed description with reference to FIG. 8. Only when material-related temperatures are exceeded do the housings of the large devices open automatically under the effect of the internal pressure, e.g. B. by lifting a lid, by melting solder joints, by evaporating and / or decomposing seals etc. After disassembly, it was found that all components were completely dry or free of hydrocarbons and PCBs and could be safely transported to further processing companies . From the sealing materials, wood and paper, only the pure, crumbling carbon was left. The weight reduction of oil-soaked paper was, for example, 73 percent by weight.

It is essential to forego a longer supply of Purge, transport and circulation gases as well as compliance with a pressure within certain limits to avoid such trailing gases constantly or in case of volume expansion over condensation surfaces lead to must, as in the prior art, and the possibility of a Recondensation of oil vapors during the heating phase.  

Advantageous further developments of the method, either individually or in Combination can be used are the subject of the rest Process claims, their advantageous effects in the detailed description exercise will be explained in more detail.

The invention also relates to devices for carrying out the method with a treatment chamber for the disposal of electrical devices, with hydrocarbons from the group PCB and PCB mixtures are filled, the treatment chamber with at least one heater device and at least one condensation device and connected to one of these downstream evacuation devices is.

To solve the same problem, the first alternative is to that with a treatment chamber with a horizontal axis and front Chamber door in front of the treatment chamber a first storage platform for the large devices with at least largely closed housings the group of transformers and capacitors is arranged and that in the treatment chamber a second storage platform for the Large devices is arranged, which is aligned with the first parking platform, such that the large devices either individually or in groups in the Treatment chamber can be set up in complete condition.

As a further alternative, to solve the same problem, that in a treatment chamber with a standing axis and lying above a cover in the treatment chamber for the Large devices with at least largely closed housings from the Group of transformers and capacitors is arranged on which the Large devices either individually or in groups in complete condition can be set up.  

Advantageous further developments of the devices, either individually or can be used in combination, are the subject of the rest Device claims, their advantageous functions in detail description will be explained in more detail.

Exemplary embodiments of the subject matter of the invention and its further refinements with regard to process management and devices are explained in more detail below with reference to FIGS. 1 to 9.

Show it:

Fig. 1 is a vertical section through a treatment chamber with a loading and unloading device for a horizontal conveyor,

Fig. 2 is a diagram with temperature and pressure and a parameter field of advantageous process parameters,

Figure 3 is a process scheme for further treatment of the extracted from the treatment chamber PCB-containing vapors. By means of an injection condenser and absorbing oils,

Fig. 4 shows an alternative process scheme for further treatment of the extracted from the treatment chamber PCB-containing vapors by means of a surface condenser,

Fig. 5 shows a comparison with FIG. 4 further developed alternative procedural rensschema for the further processing of the extracted from the lung chamber treatmen PCB-containing vapors by means of two surface condensers,

Fig. 6 is a process diagram for the final treatment of the condensates from the injection and surface condensers of FIGS. 3, 4 and 5,

Fig. 7 is a vertical section through a treatment chamber for loading and unloading in the vertical direction,

Fig. 8 is a schematic diagram of a closed transformer in a treatment chamber analogous to Fig. 7 to explain the heat and mass transfer between all components, and

Fig. 9 is a diagram for explaining the temperature profiles at different measuring points.

In Fig. 1 a treatment chamber 1 in the form of a pressure-resistant vessel 2 located with an outer casing 3 and a chamber door 4 is shown. The outer jacket 3 is lined with thermal insulation 5 and 21, which leaves a space 12 opposite the boiler 2 . A blower 6 , a feed line 7 and a discharge line 8 are provided for the passage of a coolant (eg air).

The inner surface of the boiler 2 and the chamber door 4 are kept at a temperature at which no oil condenses. In the boiler are a heater 9 , the z. B. can be designed as a resistance heater, a fan 10 and baffles 11 are provided, through which the treatment chamber 1 has the function of an oven. Alternatively or additionally, heating devices from the group of radiant heaters, heating mats that envelop the large appliances, induction coils and contact electrodes can be provided for conductive heating. An additional heating device 9 a is designed as a heating jacket with terminals 9 b and 9 c.

After an initial evacuation to remove the ambient air, a pressure is generated in the boiler 2 by means of an inert gas source 13 and a control valve 14 which corresponds to the desired process pressure. However, the inert gas is sucked off very quickly and in a controlled manner and replaced by the oil vapors that form, which is explained in more detail below.

The chamber door 4 is surrounded by a hollow seal 15 , which is kept by a temperature control circuit 16 with a thermal oil at a temperature at which the seal 15 is stable, but at which no vapors condense on it. Suitable temperatures are between about 200 ° C and 300 ° C. For this purpose, the temperature control circuit 16 has a circulation pump 17 , a heating device 18 and a cooling device 19 , which can optionally be switched on by means of a changeover valve 20 .

In front of the chamber door 4 , a storage platform 22 is arranged on the z. B. by means of a transport vehicle and a transport frame 23 two individual large devices 24 and 25 , z. B. transformers can be turned off. These can be moved into the boiler 2 by means of the transport frame 23 after opening the chamber door 4 (perpendicular to the plane of the drawing) and can be parked above the heating device 9 in the positions 23 ', 24 ' and 25 'on a further storage platform, not shown. The large devices 24 and 25 are still filled with the total amount of PCB's or PCB-containing oil. As soon as this oil has exceeded its boiling temperature (see FIG. 2) at the given internal pressure of the boiler 2 , the boiling process begins, the oil vapors taking over the main part of the heat transfer to the inner parts of the large devices 24 and 25 . This is a decisive factor for the rapid heating of the large total mass of the large devices 24 and 25 .

From the boiler 2 , a suction line 26 leads to a catalyst 27 , to which metered quantities of gases from the group hydrogen and gaseous hydrocarbons are fed from a gas source 28 via a control valve 29 , so that the PCBs are converted into the corresponding halogen compounds of hydrogen, for example in Hydrochloric acid, which can be converted into chlorides by alkali hydroxides, which can be eliminated by water washing. Via a shut-off valve 30 , the treatment chamber 1 , for. B. for charging purposes, are separated from the subsequent treatment facilities. The connection point to the treatment facilities according to FIGS. 3, 4 and 6 is indicated by the arrow 31 .

In FIG. 2, the process temperatures, "T" and in ordinate the process pressures "P" are plotted on the abscissa. In the area delimited by dashed lines there are countless vapor pressure curves for the individual oils or PCBs as well as the boiling ranges for the binders of paper, for plastics and for other possible oils and hydrocarbons. Such a vapor pressure curve for a thermal oil is exemplified by a thick line "L". There is no boiling process above the respective vapor pressure curve; if the pressure falls below and / or the temperature increases, the boiling process begins suddenly.

In FIG. 2 in a very schematic representation of an exemplary pressure is running by means of the dash-dot curve "P" shown: At the start of heating, the air atmosphere is lowered mbar at the time T1, by evacuating to a pressure of 1, which is briefly achieved at time T2. The treatment chamber is then flooded with a non-oxidative gas (inert gas) to a pressure of 400 mbar, which is reached at time T3. The inert gas supply is switched off by closing the supply valve, ie no carrier, transport or purge gas is supplied.

By a control system described in more detail below and a The control valve in front of the vacuum pump is at least the set pressure kept largely constant. With rising temperature begins now increasingly the evaporation (not yet boiling) of the liquid (coal water and pollutants) according to the equilibrium conditions in the area of the liquid, i.e. initially within the device housing. By re-condensation of the vapors on even colder parts of the device and the resulting high heat transfer become existing Temperature gradients extremely effective and reduced in a short time. Excess vapors become pressure dependent through the control valve aspirated and condensed outside the treatment chamber, so that an undesirable increase in pressure is avoided. The condensation pre  gang is not hindered by carrier, transport or purge gas because this only at the beginning of the control process, practically not later is available.

Once a predetermined temperature, the z. B. by a temperature sensor at the worst point in the core of a transformer sen and which is reached at time T4, the control valve before Vacuum pump fully opened, and the pressure is now at a value lowered below the vapor pressure curve of the liquid (line "L") in the present case to 10 mbar, whereupon the boiling process of the liquid suddenly begins. The temperature is now further increased and the pressure is reduced further until a predetermined time by time T5 Limit value for the residual content of pollutants in the device has been reached.

FIGS. 3, 4 and 5 show an essential element of the invention, namely, a valve disposed in the suction pipe 52 by the vacuum pump 53 control valve 52 a, the b via a line 52 is connected to a control with a controller 52 c which its pressure signals "P" receives a measured value line 52 d from the interior of the treatment chamber and regulates its internal pressure according to the above explanations for FIG. 2.

Fig. 3 shows the continuation of the suction line 26 , which leads to an injection condenser 32 , in the injection nozzles 33 for the generation of conical spray jets 34 of an oil from the group of mineral oils are angeord net. The spray jets create a trickle zone 35 in which the PCB vapors are condensed by the mineral oil. For this purpose, the mineral oil is circulated in a circuit 36 , to which a reservoir 37 can be connected for the supplementation of used mineral oil. The quantity to be supplied depends, among other things, on the PCB concentration in the vapors. The condensate from mineral oil and PCB's is fed via line 38 to a receiver 39 , the fill level of which is regulated by a valve 40 . From here, the condensate is fed via a cooling device 42 , a cleaning device 43 (which can be designed as a cold trap or filter) and a circulation pump 44 to a branch line 45 to which the injection nozzles 33 are connected.

A partial flow of the recooled condensate (the heat of condensation of the vapors coming from the treatment chamber 1 , which also contains most of the heating power of the treatment chamber 1 must be continuously removed) is fed via a further branch line 46 to a packed column 47 , which with the injection condenser 32 is structurally united. In the packed column 47 , further injection nozzles 48 are arranged for the production of conical spray jets 49 . The spray jets impinge on a packing zone 50 which, for. B. Raschig rings and in the remaining PCB vapors are condensed by the mineral oil. This condensate in turn runs down through the trickle zone 35 located below and combines with the condensate generated there. The outflow of excess and enriched with PCB's condensate takes place - for further processing - via a line 51 to a final processing stage according to FIG. 6. The number of injection nozzles 33 and 48 is of secondary importance; it is only necessary to ensure that the cross section of the packing zone 50 and trickle zone 35 is fully covered.

The injection condenser 32 and / or the packed column can also be operated with n-hexane and other hydrocarbon solvents or solutions of alkali metal hydroxides and / or water.

The remaining gases and vapors are withdrawn from the packed column 47 via a suction line 52 . In front of and behind a vacuum pump 53 , activated carbon filters 54 and 55 are arranged in the suction line 52 , which can be removed and also disposed of in the treatment chamber 1 by thermal desorption (VTR process). Before the gases are released into the atmosphere (arrow 57 ), they are subjected to catalytic oxidation in a catalytic converter 56 . The activated carbon filter 54 also serves to protect the vacuum pump 53 , which can consist of a complete pump set.

FIG. 4 now shows an alternative process scheme for the further treatment of the PCB-containing vapors extracted from the treatment chamber 1 by means of a surface capacitor 58 . For a targeted setting of the temperatures of the condensation surfaces, a temperature control circuit 59 is provided with a thermal oil, which has a circulation pump 60 , a heating device 61 and a cooling device 62 , which can optionally be switched on by a changeover valve 63 . The apparatus and process sequences in the further suction line 52 correspond to those in FIG. 3.

. The apparatus of Figure 4 operates in the following manner: In the upper surface of capacitor 58 is initially at temperatures between -196 ° C and + 25 ° C from the hydrocarbons, a tarry to solid condensate sat with the PCB's are formed which, after collection of a predetermined amount of condensate cyclically thawed by heating the condensation surfaces to temperatures between 100 ° C. and 400 ° C., preferably between 200 ° C. and 300 ° C. and collected in a receiver 64 , the output 65 of which leads to a final processing stage according to FIG. 6.

Fig. 5 shows a further alternative process scheme for further treatment of the extracted from the treatment chamber 1 PCB-containing vapors by means of a first surface 66 and a capacitor connected in series therewith second surface condenser 67th For a targeted setting of the temperatures of the condensation surfaces of the first surface condenser 66 , a temperature circuit 59 is also provided here, which has a circulating pump 60 , a heating device 61 and a cooling device 62 , which can be optionally switched on by a switching valve 63 . The apparatus and process flows in the further suction line 52 correspond to those in FIGS . 3 and 4.

. The apparatus of Figure 5 operates in the following manner: In the first surface condenser 66, first, at temperatures between + 150 ° C and + 300 ° C, preferably between + 200 ° C and + 250 ° C, a liquid to tarry condensate from the high-boiling steam components formed with part of the PCB's. As far as it is tarry condensate, this can be thawed cyclically by increasing the temperature and collected in the template 64 , as has already been described before. In the second surface condenser 67 a further condensate is formed at temperatures between -196 ° C and + 25 ° C from the remaining, low-boiling hydrocarbons or their vapors, which, if necessary, also accumulates cyclically by heating the condensation surfaces to accordingly higher temperatures are thawed and collected in a further template 64 a, the output 65 a of which leads to a final processing stage according to FIG. 6. For the sake of simplicity, a second temperature control circuit analogous to 59 , which is required for this, is not shown. Plates and / or tube bundles are examples of possible condensation surfaces.

FIG. 6 shows a process diagram for the final treatment of the condensates from the injection and surface condensers according to FIGS. 3, 4 and 5. The condensates from the templates 39 , 64 and 64 a are fed into a reaction container 69 via a feed line 68 . In a reservoir 70 , a dispersion of an oil and alkali metals and / or their compounds is presented, for. B. Na, NaOH, K, KOH, LI, LiOH. Liquid alkalis with the hydroxides can also be used. By means of a heating device 71 , the required reaction temperature for the elimination of the halogens from the PCBs and for the formation of halogen salts is set, which can be between 20 ° C and 400 ° C. For example, KOH has a melting point of 360 ° C so that the reaction should be carried out above this temperature and NaOH has a melting point of 324 ° C so that the reaction should be carried out above this temperature. The reaction with a sodium dispersion in oil can be carried out at temperatures between 20 ° C and 150 ° C. A stirrer 72 serves to accelerate the reaction. The reaction products are finally fed to a centrifuge 73 , from which the salts are drawn off in the direction of arrow 74 and the liquid in the direction of arrow 75 .

Fig. 7 shows a vertical section through a treatment chamber 76 for loading and unloading in the vertical direction by a lifting device, such as a crane bridge. The treatment chamber 76 has the shape of a standing vessel 77 with a pressure-resistant outer jacket 78 , an inner cover 79 and an outer cover 80 . The inner surface of the boiler 77 and the inner lid 79 are kept at a temperature at which no oil condenses at the predetermined pressure. In the boiler, a heating coil 81 is provided through which the treatment chamber 76 has the function of an oven. Alternatively, heating devices from the group of heat radiators, heating mats which surround the large device 24 (a transformer), induction coils and contact electrodes for conductive heating can be provided. Another, particularly before geous alternative is to use the usual contacts 82 of the large device 24 for supplying the heating power, so that the Pro heat is generated directly in the mass of the large device 24 . This alternative also applies to the example according to FIG. 1.

In the space 83 between the boiler 77 and the outer jacket 78 , a pressure is maintained by means of an inert gas source 86 and a control valve 87 , which corresponds to the internal pressure of the boiler 77 , so that the boiler 77 is relieved of pressure. Crane eyes 84 are used for the vertical transport of those parts to which the crane eyes 84 are attached. In this case, thermal insulation 85 is placed inside the boiler 77 .

The principle of operation of the subject matter of the invention is explained in more detail with reference to FIG. 8: a treatment chamber 88 is equipped with an outer heating device 89 and an inner heating device 90 , one of which may be sufficient. In the treatment chamber 88 there is a large device 24 , a transformer, with a housing 24 a and a cover 24 b, the flange screw connections (not shown) of which are loosened, so that the cover 24 b rests loosely. In the housing 24 a there is a core 24 c. The treatment chamber is surrounded by thermal insulation, but this is not shown.

A state is shown to the left of the center line M in which the entire operational amount of hydrocarbons 91 is still present.

To the right of the center line M is shown a state in which only a part of the operational amount of hydrocarbons 91 is present. This condition may have been reached by draining most of the hydrocarbons, or after more of the original amount has evaporated and evaporated. Evaporation or evaporation always begins on the surface of the liquid due to the hydrostatic pressure.

It follows from this that any carrier or purge gas would have no direct influence on the mass transfer inside the large device 24 . Such a carrier or purge gas is not used according to the invention.

The heat transfer to the housing 24 a takes place partly through radiation from the heated wall of the treatment chamber 88 or from the heating device 90 (if present), partly through convection and recondensation of the atmosphere in the treatment chamber 88 . In the liquid hydrocarbons 91 , too, an increasingly stronger convection flow forms with the rise in temperature, which increases the heat transfer to the core 24 c via the heat conduction considerably. Right of the center line forms in the vapor space 91 a top half of the liquid hydrocarbons 91, a convection flow and a re-condensation of the vaporous hydrocarbons, which significantly enhances the influence of the heat transfer by radiation.

Now there are also 24 c cavities in the core, some in pore size, which are initially filled with the liquid hydrocarbons. Evaporation and evaporation also begin there - initially from the surface of the core 24 c - with increasing effect. Recondensation of the vapors also results in an increased or accelerated heating of the core 24 c to the respectively predetermined temperature. This means that the omission of carrier or purge gas prevents premature removal of the already evaporated or evaporated hydrocarbons, and that they are available for heating by re-condensation, at least until some of these vapors are reached when a predetermined pressure level is reached is subtracted. This reduces undesired energy losses to a minimum.

In the diagram according to FIG. 9, the time "t" is plotted on the abscissa and the temperature "T" on the ordinate. A dash-dotted curve 92 shows the inner wall temperature of the treatment chamber, as set by controlled jacket heating. The dashed curve 93 shows the associated temperature curve of the steam atmosphere within the treatment chamber, for. B. measured in the upper region of the treatment chamber. The drawn curve 94 shows the associated temperature profile within the transformer core, z. B. measured at a depth of about 20 cm along the center line "M". It can be seen that, despite the absence of a circulating hot gas, curves 93 and 94 differ only slightly from one another. The points at which the steep slopes of the curves begin mark the end of the heating-up phase, at which a noticeable part of the hydrocarbons has already evaporated or evaporated. The evaporation continues, however, due to the stored thermal energy and falling below the vapor pressure curves, until the predetermined limit value of PCBs is reached. In this case, the heating phase extends over approximately 10 hours, the cooling phase also over approximately 10 hours.

Reference list

1

Treatment chamber

2nd

boiler

3rd

Outer jacket

4th

Chamber door

5

Thermal insulation

6

fan

7

Supply line

8th

Discharge line

9

Heating device

9

aHeating device

9

b Terminal

9

b Terminal

10th

fan

11

Baffles

12th

Space

13

Inert gas source

14

Control valve

15

poetry

16

Temperature control circuit

17th

Circulation pump

18th

Heating device

19th

Cooling device

20th

Diverter valve

21

Thermal insulation

22

Parking platform

23

Transport frame

23

'Position

24th

Large device

24th

'Position

24th

a housing

24th

bLid

24th

core

25th

Large device

25th

'Position

26

Suction line

27

catalyst

28

Gas source

29

Control valve

30th

Shut-off valve

31

arrow

32

Injection condenser

33

Injectors

34

Spray jets

35

Trickle zone

36

Circulation

37

Storage container

38

management

39

template

40

Valve

41

management

42

Cooling device

43

Cleaning facility

44

Circulation pump

45

Branch line

46

Branch line

47

Packed column

48

Injectors

49

Spray jets

50

Packed zone

51

management

52

Suction line

52

a control valve

52

b Management

52

c controller

52

dMeasurement line

53

Vacuum pump

54

Activated carbon filter

55

Activated carbon filter

56

catalyst

57

arrow

58

Surface capacitor

59

Temperature control circuit

60

Circulation pump

61

Heating device

62

Cooling device

63

Diverter valve

64

template

64

a template

65

output

65

aOutput

66

Surface capacitor

67

Surface capacitor

68

Supply line

69

Reaction vessel

70

Storage container

71

Heating device

72

Stirrer

73

centrifuge

74

arrow

75

arrow

76

Treatment chamber

77

boiler

78

Outer jacket

79

inner lid

80

outer cover

81

Heating coil

82

Connection contacts

83

Space

84

Crane eyes

85

Thermal insulation

86

Inert gas source

87

Control valve

88

Treatment chamber

89

outer heater

90

inner heater

91

Hydrocarbons

91

a steam room

92

Curve (dash-dotted)

93

Curve (dashed)

94

Curve (extended)

Claims (31)

1. A method for disposing of large electrical devices ( 24 , 25 ) with at least largely closed housings from the group of transformers and capacitors, which are filled with hydrocarbons from the group of PCBs and PCB mixtures, by thermal recycling, characterized in that

• a) the large devices ( 24 , 25 ) together with their housings and with at least part of the operational amounts of these hydrocarbons are introduced into a treatment chamber ( 1 , 76 , 88 ) and that the treatment chamber ( 1 , 76 , 88 ) for removing the Ambient air is evacuated to a pressure of less than 10 mbar and then flooded with a non-oxidative gas to a pressure above 30 mbar,
• b) a pressure above 30 mbar is maintained in the treatment chamber ( 1 , 76 , 88 ) in a heating phase without the supply of purge gas by regulating the extracted gas and steam quantities until a predetermined temperature is reached inside the large devices ( 24 , 25 ) is reached, which is above the vapor pressure curves at which the hydrocarbons evaporate by boiling, causing released vapors to condense again at relatively colder locations within the housing in order to accelerate the heating process while the controlled evacuated hydrocarbon vapors are condensed,
• c) the pressure in the treatment chamber ( 1 , 76 , 88 ) after Errei chen the predetermined temperature is reduced to a value which is below the said vapor pressure curves, and that
• d) the hydrocarbons are evaporated by boiling and purging gas is freely condensed and, if necessary, further treated with destruction of the PCBs.

2. The method according to claim 1, characterized in that the large devices ( 24 , 25 ) are treated with an initial filling of the total operational amounts of these hydrocarbons. 3. The method according to claim 1, characterized in that the heating by at least one energy input from the group
Heat radiation,
Induction heat,
Heat of conduction,
Steam circulation,
Steam condensation,
Current heat is carried out via the connection contacts. 4. The method according to claim 1, characterized in that the Evaporation of the hydrocarbons including the PCB's Temperatures between 100 ° C and 400 ° C and at chamber pressures between 0.01 mbar and 400 mbar. 5. The method according to claim 4, characterized in that the Treatment started at an initial pressure of maximum 400 mbar and that the temperature of the large devices to a maximum of 400 ° C is increased while the chamber pressure to values of is reduced by a maximum of 0.1 mbar. 6. The method according to claim 1, characterized in that the hydrocarbons including the PCB's are sucked into an injection condenser ( 32 ) with at least one first injection nozzle ( 33 ) and in a trickle zone ( 35 ) by means of a predetermined amount of an oil from the group of Mineral oils are condensed, the oil being circulated in a circuit ( 36 ) via at least one cooling device ( 42 ) and the portion which exceeds the predetermined amount is collected in a receiver ( 39 ) in a level-controlled manner. 7. The method according to claim 6, characterized in that above the first injection nozzle ( 33 ) of the injection condenser ( 32 ) a packed column ( 47 ) with at least one second injection nozzle ( 48 ) is arranged in the oil mist by means of the same, in the circuit ( 36 ) circulated oil, and that this circulating oil is also passed through the trickle zone ( 35 ). 8. The method according to claim 6, characterized in that the exhaust gas of the injection condenser ( 32 ) is sucked off by means of a vacuum pump ( 53 ) and, before being released to the atmosphere, is passed through at least one activated carbon filter ( 54 , 55 ), that the activated carbon filter ( 54 , 55 ) with their filter chambers after at least partial loading of PCBs in the treatment chamber ( 1 , 76 , 88 ) are subjected to a desorption process and that the desorbed vapors are passed into the injection condenser ( 32 ). 9. The method according to claim 8, characterized in that one of the activated carbon filters ( 54 ) is connected upstream of the vacuum pump ( 53 ). 10. The method according to claim 8, characterized in that the exhaust gases of the vacuum pump ( 53 ) are subjected to a catalytic oxidation. 11. The method according to claim 1, characterized in that a catalyst ( 27 ) is arranged in a suction line ( 26 , 52 ) of the treatment chamber ( 1 , 76 , 88 ) in which the PCB's are fed with gases from the group hydrogen and gaseous hydrocarbons are thermally converted into the corresponding halogen compounds of hydrogen. 12. The method according to claim 1, characterized in that the furnace exhaust gases are passed into a surface condenser ( 58 ) in which a tar to solid condensate is formed at temperatures between -196 ° C and + 25 ° C from the hydrocarbons, the after accumulation of a quantity of condensate by heating the surface capacitor ( 58 ) to temperatures between 100 ° C and 400 ° C, preferably between 200 ° C and 300 ° C, thawed cyclically and collected in a template ( 64 ). 13. The method according to claim 12, characterized in that the furnace gases are passed into a first surface condenser ( 66 ), in which a first condensate is formed from the hydrocarbons at temperatures between 150 ° C and 250 ° C, that the first condensate after Accumulation of a quantity of condensate by heating the first surface condenser ( 66 ) to temperatures between 200 ° C and 300 ° C, cyclically thawed and collected in a first receiver ( 64 ), and that the exhaust gases of the first surface condenser ( 66 ) pass to a second surface condenser 64 a) are fed in which further hydrocarbons condensed between -196 ° C and + 25 ° C and a second template ( 64 a) are fed. 14. The method according to at least one of claims 1, 6, 12 and 13, characterized in that the contents of the templates ( 39 , 64 , 64 a) in a reaction container ( 69 ) with the addition of at least one reagent from the group of alkali metals and the alkali metal hydroxides are neutralized at temperatures between 20 ° C. and 400 ° C. in such a way that the corresponding halogen compounds of the alkali metals are formed. 15. The method according to claim 14, characterized in that the at least one reactant from the group of alkali metals and the alkali metal hydroxides in the form of a dispersion in one Mineral oil is supplied. 16. The method according to claim 15, characterized in that the content of the reaction container ( 69 ) is centrifuged to separate halogen compounds of the alkali metals and mineral oil. 17. Device with a treatment chamber ( 1 ) for the disposal of electrical devices which are filled with hydrocarbons from the group PCB and PCB mixtures, the treatment chamber ( 1 ) with at least one heating device ( 9 , 9 a) and at least A condensation device and is connected to an evacuation device connected downstream thereof, characterized in that in the case of a treatment chamber ( 1 ) with a lying axis and chamber door on the front ( 4 ) in front of the treatment chamber ( 1 ), a first storage platform ( 22 ) for large devices ( 24 , 25 ) with at least largely closed housings from the group Trans formers and capacitors is arranged and that in the treatment chamber ( 1 ) a second storage platform for the said large devices ( 24 , 25 ) is arranged, which is aligned with the first storage platform ( 22 ), such that the large devices ( 24 , 25 ) either individually or in groups in the treatment comb er ( 1 ) can be set up in a complete state. 18. Device with a treatment chamber ( 76 ) for the disposal of electrical devices that are filled with hydrocarbons from the group PCB and PCB mixtures, the treatment chamber ( 76 , 88 ) provided with at least one heating device ( 81 ) and at least one Condensation device and is connected to an evacuation device connected downstream thereof, characterized in that in the case of a treatment chamber ( 76 , 88 ) with a standing axis and an overhead cover ( 79 , 80 ) in the treatment chamber ( 76 ), a storage platform for large devices ( 24 , 25 ) with at least one largely enclosed housings from the group of transformers and capacitors is arranged, on which the large devices ( 24 , 25 ) can be set up either individually or in groups in complete condition. 19. Device according to one of claims 17 and 18, characterized in that the treatment chamber ( 1 , 76 , 88 ) is assigned a pressure sensor, the output of which is connected to a controller ( 52 c), the output of which is in turn a control valve ( 52 a) is connected, which is arranged in the suction line ( 52 ) between the treatment chamber ( 1 , 76 , 88 ) and the vacuum pump ( 53 ) and through which the suction power of the vacuum pump ( 53 ) in accordance with a setpoint for the internal pressure of the treatment chamber ( 1 , 76 , 88 ) can be regulated. 20. Device according to one of claims 17 and 18, characterized in that at least one heating device from the group resistance heating ( 9 ), heating coil ( 81 ), heat radiator, induction coil and contact electrodes is provided as the heat source. 21. Device according to one of claims 17 and 18, characterized in that the treatment chamber ( 1 , 76 , 88 ) has an injection condenser ( 32 ) with at least one first injection nozzle ( 33 ) for a treatment oil, under which there is a trickle zone ( 35 ) is located, the injection condenser ( 32 ) being assigned a circuit ( 36 ) with at least one cooling device ( 42 ), and that to the circuit ( 36 ) a template ( 39 ) for receiving the circuit oil with the PCB's is connected . 22. The apparatus according to claim 21, characterized in that above the trickle zone ( 35 ) of the injection condenser ( 32 ) a Füllkör percolonne ( 47 ) with at least one second injection nozzle ( 48 ) is arranged, which is connected to the same circuit ( 36 ). 23. The apparatus according to claim 21, characterized in that a vacuum pump ( 53 ) is connected to the injection condenser ( 32 ) and that at least one activated carbon filter ( 54 , 55 ) is arranged in the suction line ( 52 ) with the vacuum pump ( 53 ). 24. The device according to claim 23, characterized in that one of the activated carbon filters ( 54 ) is connected upstream of the vacuum pump ( 53 ). 25. The device according to claim 21, characterized in that the vacuum pump ( 53 ) is followed by an oxidizing catalyst ( 56 ). 26. Device according to one of claims 17 and 18, characterized in that a catalyst ( 27 ) is arranged in a suction line ( 26 ) of the treatment chamber ( 1 , 76 , 88 ) in which the PCB's are fed with gases from the group Hydrogen and gaseous hydrocarbons can be thermally converted into the corresponding halogen compounds of hydrogen. 27. The device according to one of claims 17 and 18, characterized in that the treatment chamber ( 1 , 76 , 88 ) is followed by at least one surface condenser ( 58 , 66 , 67 ) in which a tar to solid condensate can be produced from the hydrocarbons and that the surface condenser ( 58 , 66 , 67 ) is connected to a temperature control circuit ( 59 ) which can be switched cyclically between a condensation phase and a defrosting phase, and that the surface condenser ( 58 , 66 , 67 ) has a template ( 64 , 64 a) is connected downstream for collecting the defrosted condensate. 28. The apparatus according to claim 27, characterized in that the surface capacitor ( 66 ) is followed by a second surface capacitor ( 67 ) with a second template ( 64 a). 29. The device according to at least one of claims 27 and 28, characterized in that on the templates ( 39 , 64 , 64 a) each have a reaction container ( 69 ) for the reaction of at least one reagent from the group of alkali metals and the alkali metal hydroxides in the corresponding halogen compounds of the alkali metals is assigned. 30. The device according to claim 29, characterized in that the reaction vessel ( 69 ) is followed by a centrifuge ( 73 ) for separating halogen compounds of the alkali metals and mineral oil. 31. The device according to claims 21 and 22, characterized in that the injection capacitor ( 32 ) and the packed column ( 47 ) are structurally combined.