EP1263549B1 - Method and device for cleaning high-voltage carrying installation component parts - Google Patents

Abstract

A cleaning method and a corresponding cleaning device offer adequate protection to individuals, devices and installations, for cleaning component parts of installations that carry an electrical high-voltage and which are not disconnected during cleaning. Towards this end, the component parts to be cleaned are subjected to the action of a two-phase particle stream (PS) consisting of a compressed gas (DGA) serving as a carrier medium and of carbon dioxide ice particles (TP) carried therein. Possible superficial accumulations of dirt are removed from the component parts by way of low-temperature embrittlement and by the kinetic energy of the impacting carbon dioxide particles. The carbon dioxide ice particles themselves sublimate without leaving residues. A sufficiently safe distance of cleaning personnel from the high-voltage carrying insulation component parts is ensured by the provision of an electrically insulating distance mechanism (L, SFR) that is provided approximately in the form of a lance (L) or of a stream guided tube (SFR). A further increase in protection is offered by monitoring the quantity of moisture of compressed gas and/or ambient air, whereby the cleaning device is immediately shut off when predetermined limiting values are exceeded.

Description

The invention relates to a cleaning method and a cleaning device for system parts that have an electrical Lead high voltage.

Components in systems of electrical energy supply such as e.g. in substations and switchgear get dirty over time due to operational, environmental or special influences (e.g. Fires). The contamination or buildup is complete of different nature: they range from only loosely adhering dust-like contamination of inorganic or organic Nature, about oils, fats liquid films and so-called Biofilms from fungi and algae (especially in open air systems) down to almost burned-in residues Metals, metal oxides and carbon, e.g. at Arcing or arcing.

To maintain the operational safety of such systems must receive parts of such facilities from time to time getting cleaned. For example, electrically conductive buildup on the surface of a ceramic insulator even if they have low electrical conductivity, the insulating effect of an insulator through leakage currents reduce and in extreme cases even the emergence of a Arc and thus at least briefly to a malfunction to lead. Consequences of such malfunctions are enough from brief interruptions to plant fires.

For cleaning, the known physical and chemical Cleaning procedures are used. But have to usually for the safety of the cleaning staff the systems are taken out of operation and activated, i.e. it must be ensured that the electrical high voltage is switched off. This requires at least during the duration of cleaning is a business interruption that is economical is disadvantageous and often technical Problems. The economic damage, the energy supply and industrial companies through the at Cleaning of high voltage systems required longer Activation occurs, is considerable and would be too avoiding it requires considerable additional effort in the cleaning process justify.

Chemical cleaning procedures are based on exposure of a cleaning agent that adheres to the component Dirt particles are subjected to a chemical reaction and thereby detach from the component. Cleaning procedures that usually work with chemical cleaning agents also liquid or solid residues, depending on the nature pose a risk to the operational safety of a plant. You can e.g. even as a kind of pollution act, and affect the insulation effect of system parts or favor the corrosion of plant components. Therefore, the cleaning agents themselves usually have to be used again elaborately removed what the cleaning process complicated and time consuming.

Purely physical processes have these disadvantages Not. With these processes, the contaminants become pure mechanically abraded from the component. They are in their cleaning effect especially with oils and fats often not as good. In such a process e.g. for cleaning a high pressure water jet that is directed towards the cleaning system parts is used. Such Wet cleaning processes have serious disadvantages: on the one hand the high humidity can cause corrosion on the contact parts lead to the other also dirty and with it contaminated wastewater that is disposed of or reprocessed Need to become. Without the addition of cleaning or Solvents are the removal of greasy or oily Residues only possible to a limited extent. And ultimately water shows a relatively high electrical conductivity. A cleaning under voltage, i.e. on a not activated System, is without endangering the cleaning staff at most in the low voltage area (i.e. in the area below 1 kV) possible.

Mechanical cleaning processes also include Also the particle beam process, e.g. the sandblasting. Most of these processes (more precisely with most of the abrasives used) strong abrasive effect on the surface of the surface to be cleaned Parts are affected.

The use of dry ice particles is a certain exception as abrasive particles from carbon dioxide in solid phase, e.g. from the German patent applications DE 195 44 906 A1 and DE 196 24 652 A1 is known. Dry ice particles are quite soft (they have about that Hardness of plaster) and therefore do not damage the surface. In the meantime, the use of dry ice as an abrasive quite common for cleaning purposes. Besides, will a cleaning effect not only through the kinetic energy of the impacting dry ice particles but also through other factors. This is how the dry ice particles sublimate either on impact or immediately after. The they withdraw relatively high heat of sublimation thereby the point of impact, resulting in a strong local cooling the impact surface or the one adhering to it Pollution. The resulting thermal stresses loosen the bond between dirt or covering and Surface of the system parts to be cleaned. By solidification and embrittlement of the dirt will also reduce adhesion reached. After all, that means sudden Sublimation of the dry ice particles an almost explosive Volume increase by about a factor of 600, resulting in a blasting or blowing off the already loosened dirt and leads.

A big advantage of cleaning processes with dry ice is especially in the fact that the dry ice particles completely and residue-free to carbon dioxide in the gaseous state sublimate. This means no additional contaminated Amounts of waste. The only waste is volume the removed and removed dirt particles and impurities dispose.

Unfortunately, the devices and processes are suitable for cleaning Dry ice particles, such as those from e.g. from the two before documents cited are not known directly to Cleaning of high voltage systems that have not been activated since neither device nor personal protection against high voltage consists. For example, the cleaning staff too strong the approach the system to be cleaned, so that there is a risk of high voltage flashover consists.

In addition, one must in principle with the appearance of two essential Problems reckon with condensing humidity, which creates additional conductivity, and with the effects of the removed dirt particles.

It is expected that by bringing in the extreme cold dry ice particles (carbon dioxide has a sublimation point from -78 ° C to) condensation in the Ambient air and possibly also contained in the compressed gas Humidity comes and thereby a reduction in Isolation properties of the ambient air. Especially with indoor systems, their insulation distances are not condensing Moisture, this could fatale Consequences. This could lead to voltage flashovers come with arcing faults that are not just system safety but also considerably the safety of the cleaning staff would endanger. Because the minimum safety clearances are calculated for normal plant operation, Arcing, however, experience a considerably wider spread the cleaning staff would help themselves Working at a distance from a considerable risk of injury especially exposed to burns.

Another point of danger is that also those for Transport of the dry ice particles used compressed air Contains moisture that creates a certain conductivity and thereby both the cleaning staff as well the cleaning device is endangered.

The second problem is the removed dirt particles The dry ice is not simply "snow" over the system sprayed but hits with high kinetic Energy dissolves on the surfaces to be cleaned and dissolves there the dirt particles. As already stated, these exist not infrequently from flammable and partly also electrical conductive substances. Finely distributed in the ambient air a high-voltage system you have to expect that they also reduce the insulation strength and in turn lead to arcing faults or their effects favor. Even dust explosions are first of all not to be excluded but rather to be expected.

The importance of these danger points is of course strong of the respective system and in particular the amount of the adjacent Voltage dependent. What almost no with 3 kV systems and with 30 kV systems is not yet a major problem develop into a deadly threat in 300 KV systems.

The invention is therefore based on the object of a cleaning method and a cleaning device to be used for this to create, which make it possible to plant parts that lead high voltage, simple and for the Operator and the plant safe way of contamination and Clean build-up without the corresponding parts of the system would have to be unlocked.

This object is achieved according to the invention by a method Claim 1 and a device with the in the claim 9 and / or a use with those in the claims 22 to 24 listed features solved. advantageous Refinements and developments of the invention result itself from the subclaims.

Extensive experimental investigations carried out by the inventor have the unexpected result that the expected problems from moisture condensation and by whirling up the dirt particles actually in not appear in this form, but paradoxically that Insulation resistance of the mixture of ambient air, compressed gas, Carbon dioxide gas, cold dry ice particles, condensed water and dirt particles actually not less but is usually even higher than that of conventional ones Ambient air.

Since, according to the experimental results, the technical do not increase the required insulation distances the basic idea of the cleaning method according to the invention and the device used to clean them To apply a dry ice particle jet to the system parts, but with an insulating spacer ensure that the cleaning staff always have one Minimum distance from the place where the particle beam hits the Plant part to be cleaned, adheres to, this The minimum distance is dimensioned such that the electrical personal protection guaranteed even when the system is not activated is. The experimental results show that the Sufficient use of an insulating spacer is a safe for plant and cleaning staff To ensure cleaning.

With the cleaning method according to the invention and the associated Device becomes possible for the first time without any risk of the cleaning staff under high electrical voltage standing parts of the plant without cleaning agents, the fixed or leave liquid residues to clean. The cleaning quality is doing to the needs of electrical Systems matched - greases, pollution and Fire damage in the event of a malfunction can be completely removed, without damaging the components of the electrical system would take.

Developments of the cleaning method according to the invention and the device used for this see an additional one Monitoring the humidity of the compressed gas and / or the ambient air in front. This will make even extremely unfavorable Circumstances such as high air humidity or missing dry ice particles always ensures personal and system safety. Another training course is also available Improve security by monitoring insulation properties of the spacer. Another modification of the inventive method and the device provides for suction of the detached dirt particles. This speeds up and simplifies the cleaning process.

Further advantageous refinements and developments of Invention are in connection with the illustrated embodiments described.

Fig. 1

einen Strahlgenerator zur Erzeugung eines Partikel-strahls nach dem Stand der Technik

Fig. 2

eine schematische Darstellung einer Augestaltung der erfindungsgemäßen Vorrichtung zur Durchführung des Reinigungsverfahrens

Fig. 3

ein modifiziertes Abstandsmittel für die erfindungsgemäße Vorrichtung

Some preferred exemplary embodiments of the invention are described below with reference to the drawings. It show

Fig. 1

a beam generator for generating a particle beam according to the prior art

Fig. 2

is a schematic representation of an eye design of the device according to the invention for performing the cleaning process

Fig. 3

a modified spacer for the device according to the invention

For the sake of clarity, the drawings are not executed to scale.

The heart of every device for cleaning with The jet generator forms the dry ice particles cleaning two-phase jet consisting of the compressed gas as Carrier medium and the carried dry ice particles generated. The following will simplify the particle beam spoken.

Fig. 1 shows a beam generator as it is from the prior art Technology is known and also as part of the invention device can be used. A compressed gas is supplied via the compressed gas line DGL (e.g. a hose), Dry ice particles TP via the particle line PL. The Compressed gas emerges from a nozzle DÜ into the blasting chamber SK. Due to the greatly increased flow velocity of the Pressurized gas creates a negative pressure in the blasting chamber SK, which leads to the dry ice particles TP over the particle line PL sucked in, torn into the compressed gas jet and be carried along by him. The particle beam PS Comes from compressed gas as a carrier medium and dry ice particles then through the beam outlet opening SA to the outside. to Directional selection of the beam and for easier positioning of the cleaning jet can be as shown in Fig. 1 there is a short piece of pipe SF for beam guidance. The end of the pipe section SF forms the beam outlet opening. The length of the pipe section SF can vary also on the material thickness of the wall of the blasting chamber SK reduce, i.e. it is almost completely eliminated.

For conventional, non-live components can the one emerging from the beam outlet opening SA Particle jet now simply on the component to be cleaned are directed there and causes the cleaning process described. The cleaning staff holds the Beam generator SG on the handle HG (located on the handle there is also a DGS pressure gas switch with which the Compressed gas supply and thus the jet generation on and can be switched off and any additional control elements for pressure and gas volume adjustment) and aligns it on the surfaces to be cleaned. To do this, the cleaning staff but within a few centimeters of the one to be cleaned Approach component - with high-voltage system components a life-threatening because of the risk of electric shock Undertaking. This applies even more than the beam generators according to the prior art a metallic and thus have a conductive housing.

Of course, are also for the device according to the invention other beam generators are suitable. This also includes beam generators, which also has a tangential acceleration the dry ice particles cause. Such a beam generator is e.g. known from PCT application WO 99/43470. Another suitable form of a beam generator known to the person skilled in the art contains a mixing device in which a feed device (e.g. in the form of a screw conveyor) dry ice particles in the supplied through a compressed air line Compressed air flow injected. A transport hose guides it like this generated two-phase flow from compressed gas and dry ice particles u. U. over a relatively long distance to the actual Blasting gun, at the front end of which is the blasting outlet SA is located. The blasting gun then only has still the task of enabling the operating personnel To direct the beam onto a workpiece and the beam if necessary on or off. This arrangement has the advantage that instead of two separate compressed gas and particle lines only a single transport hose is required for the two-phase current is.

Fig. 2 shows a schematic representation of the invention Contraption. Corresponds in essential parts a particle beam system according to the state of the art Technology such as is described in DE 19544906 A1. The required compressed gas, i.e. a pressurized gas Gas, which later serves as a carrier medium, either delivers internal pressure gas generator DGG, for example a compressor or a pressurized gas bottle, or the pressurized gas is over an external compressed gas connection DGA, for example from a Compressed gas treatment installed in the system to be cleaned fed. The preferred pressure gas is preferred for reasons of cost Compressed air used. In principle, it also comes any other particularly inert gases such as e.g. nitrogen or argon.

From the external compressed gas connection DGA or the internal compressed gas generator DGG is the compressed gas via a valve V for interruption the compressed gas supply, especially in the event of an emergency shutdown through the DGS compressed gas line to the jet generator SG headed. The dry ice particles come from one Dry ice storage container TV via the particle line to Beam generator SG. You can already use the dry ice particles prefabricated e.g. obtain as rice grain-sized particles and then fill into the dry ice storage container TV. Indeed there is also the possibility of only immediately To generate place. This can be done, for example, by adiabatic expansion of carbon dioxide gas happen. Appropriate Possibilities for this are known to the person skilled in the art and need not be discussed further here. In In this case, the device contains a particle generator in addition to or instead of the dry ice storage container TV. It is also possible to remove the dry ice particles from the Dry ice storage container TV still to be worked on, for example to grind particularly small or sharp-edged particles, before they get to the beam generator. Appropriate procedures and arrangements for this are e.g. from document DE 19636304 A1 known. The components shown so far are located with the exception of the beam generator (according to FIG. 1) as in Fig. 2 only indicated on a common equipment carrier.

So far, the device described corresponds to one conventional cleaning device. The big problem one conventional arrangement is that the small Working distance a strong approach of the cleaning staff to the system to be cleaned and under high voltage required, whereby the electrical personal protection no longer is guaranteed. To solve this problem, see device according to the invention a kind of electrically insulating Lance L as a spacer, at one end of which actual beam generator SG is attached. On the other end there is a handle HG for holding and guiding the Lance L. There are one or more above the handle HG Handle protection plate HGT arranged, the one or the one should avoid that the lance L above the handle HG is kept by the cleaning staff, and on the other hand high moisture a continuous liquid film prevent along the lance surface.

The lance L itself must be electrically insulating. she therefore preferably consists of a plastic with high dielectric strength such as polycarbonate. Hygroscopic plastics such as Are nylon less suitable. However, it is not absolutely necessary that the lance L is made entirely of an insulating material exists, it is generally sufficient if at least one of the Isolation section corresponding to the voltage applied to cleaning is available. The length of the lance L or more precisely said the distance between the handle HG and the beam outlet SA is dimensioned so that it is at least equal to that of the high-voltage system part to be maintained equivalent. The required safety distance depends on the environmental conditions and especially the Of the applied electrical voltage. In Germany the required safety clearances are in the VDE regulation VDE 0105 specified. Demmach is currently Status of those to be observed by a 400 kV system Distance 3.40 m. Taking into account the length of the handle HG becomes a lance for such a system choose about 4 m in length. In addition to the lance with this Arrangement of course also the pressure gas line DGL and Particle line PL to be electrically insulating, as it is in the immediate vicinity of the beam outlet opening SA are located. If you use plastic hoses as feed lines, so this shouldn't be a problem.

The gas pressure switch DGS can with this device are of course not directly on the beam generator SG. It is usefully in the compressed gas line on the handle HG relocated so that the cleaning staff the jet generator SG can control without having to take your hand off the handle HG would have to take.

In a preferred development of the invention The device serves primarily as a spacer Lance L also acts as a feed for the compressed gas and / or the dry ice particles to the jet generator SG. To it is sufficient to design the lance as a tube or double tube and Then pressurized gas and / or the via this pipe or these pipes Feed dry ice particles to the jet generator. The Attachment of the DGS pressure gas switch to the HG handle making it even easier, of course. The integration at least one of the leads to the beam generator in the as a spacer Lance L used has the advantage of being less Weight and easier handling of the cleaning device.

Another preferred modification of the invention Cleaning device is already shown in Fig. 2. The Beam generator SG and the beam outlet opening SA are namely arranged so that the beam direction is not easy is to be regarded as an extension of the lance L. The beam direction and are the preferred direction of the spacer so not collinear. This angle of the beam direction Facilitates cleaning in systems that are not common to all Pages are accessible. With an angle of at least For example, the backs of the high-voltage cables can also be turned 90 ° Clean components from the front. Especially It is of course advantageous if the angle is about adjust a lockable swivel and so the respective Cleaning case can be adjusted.

According to a further preferred embodiment of the invention Cleaning device is as shown in Fig. 3 not use a lance as a spacer, but on the beam generator SG according to FIG. 1 becomes a continuous Length of the beam guiding tube slightly widening in a funnel shape SFR placed so that the beam outlet opening SA now through the front end of the beam guide tube SFR is formed. This beam guide tube, that of an electrically insulating material, preferably a plastic such as polycarbonate, so acts as Spacing means. Its length must be at least that safety distance required for the high voltage present correspond. The beam guide tube SFR leads the from Beam generator SG generated particle beam, i.e. it cares for the fact that a jet flow that is as laminar as possible occurs and prevents turbulence. This form of cleaning device is lighter and therefore easier to use than the one previously described. As with the spacer Fig. 2 is here again for the same reasons Handle protection plate HGT provided. The grip protection plate protects in particular a hand rest HG ', which next to the handle HG is attached. This makes it an ambidextrous Can guide the device when cleaning. For the required minimum length of the beam guide tube SFR is of course the minimum distance between the beam outlet opening SA and handle HG or hand rest HG ' crucial.

With this configuration, as before, again shortly before the beam exit opening SA, a beam deflection or deflection be provided to also covert areas of the System parts to clean.

Condensing moisture poses when electrical is present High voltages are a safety problem. This applies especially in high-voltage systems indoors, the unlike most outdoor systems, not condensing Moisture are designed. The cold ones Dry ice particles and in particular their sublimation Cooling down can easily lead to condensation to lead. In particular, problems can arise if the Supply of the insulation properties mentioned at the beginning essential dry ice particles are temporarily interrupted, the compressed gas still has a high level of moisture and the plant parts to be cleaned due to their relatively high Heat capacity remain very cold at first. To a sufficient Maintain personal and plant protection, is therefore in a further development of the invention Cleaning procedures that monitor moisture. The important thing is the relative humidity in the ambient air and in particular the moisture in the compressed gas or in the compressed gas / particle jet. The further development of the cleaning method according to the invention sees a monitoring of moisture in the ambient air and / or in compressed gas or in Particle beam before. When predetermined limit values are exceeded for the moisture, the actual cleaning process not recorded at all or canceled immediately (this can, for example, by an interruption of the compressed gas supply done) or the system to be cleaned immediately switched off. The required limit values depend in particular on the height of the adjacent High voltage from. Investigations have e.g. shown that a 400 kV system in any case safely with a relative Air humidity (ambient air) cleaned below 80% can be.

The limit for the humidity of the compressed gas as a carrier medium the particle beam is somewhat more difficult to define. critical is of course the moisture in the particle beam. But the humidity of the pressure gas does not necessarily have to be measured there become. It can be somewhere between the DGG gas generator or

Pressurized gas connection DGA and the particle beam behind the Beam outlet opening can be measured. Depending on the measuring location the compressed gas is in a different pressure state and therefore has a different moisture value. Between the values but there is a clear connection, so that the corresponding Limit values can be converted into each other. To carry out moisture monitoring of the compressed gas, 1 has a cleaning device Compressed gas moisture sensor DFS arranged here in the compressed gas supply. The structure and mode of operation of such sensors can relevant literature are taken and is the expert known. If the set limit is exceeded again the cleaning process canceled or not at all just added. The compressed gas humidity sensor DFS can do this Shut off the compressed gas supply using valve V. If you do that Compressed gas moisture sensor in the jet generator, in the jet guide tube or even just in front of or behind the beam outlet arranges, it must be ensured that the electrical Isolation of the spacer not by the electrical Leads of the sensor is impaired. This can e.g. by means of appropriate insulation of the supply lines. However, fiber optic transmission is even safer Measured values or the use of an optical or fiber optic moisture sensor

A compressed gas moisture sensor DFS in the compressed gas supply has the Another advantage is that it is independent of security aspects the humidity of the supplied compressed gas continuously can be monitored. Excessive humidity in the compressed gas can namely cause the dry ice particles to cake and clump together. At best this will only the cleaning effect deteriorates, in the worst case May cause temporary constipation and blockage of the Transport routes for the dry ice particles come. After a interrupts another advantageous embodiment of the invention a control of the compressed gas supply (e.g. via a Solenoid valve) as soon as the pressure gas humidity sensor DFS measured moisture in the compressed gas exceeds a value at to expect a clumping of the dry ice particles is.

An ambient air humidity sensor can be used to measure the humidity of the ambient air UFS are in the order of the also valve V when the humidity limit value is exceeded closes.

Instead of the previously mentioned moisture sensors, of course always also step dew point sensors. In particular, too monitoring for condensing water vapor, i.e. the The formation of dew can be provided. This would correspond to that a relative humidity of 100% as a limit. Especially when measuring the humidity of the ambient air this measurement can also be a temperature measurement can be supplemented by a more precise determination of the moisture limit value to enable.

After a further modification of the cleaning method according to the invention the beam guide tube is heated to this creates a film of moisture due to superficial condensation to avoid.

In another modification of the cleaning method according to the invention or the corresponding device the insulation properties of the spacer (e.g. e.g. Resistance, impedance or dielectric strength) e.g. by a leakage current measurement is monitored. Fig. 3 shows a corresponding modified spacer. On the spacer - preferably in the middle - there is one first electrode IME1, near the handle HG one second electrode IME2. This allows the impedance between the first electrode IME1 and the second electrode IME2 measured become. How such a measurement (especially with AC to ensure adequate galvanic Separation and with high voltage to also non-linear Including effects) can occur, is known to the person skilled in the art. The impedance measurement can be carried out before the actual cleaning process or at regular intervals in between or take place continuously. Alternatively you can only with one preferably in the middle of the spacer attached electrode IME1 work with the system ground connected is. The leakage current over this first Electrode IME1 is a good measure of the insulation properties of the spacer. If one is exceeded predetermined threshold value (or falling below at a Impedance or resistance measurement) can then be a controller either issue a warning to the operating personnel or but an emergency shutdown of the cleaning device or of the system to be cleaned.

Finally sees another development of the invention Cleaning process and the necessary A pneumatic suction device through the particle beam chipped or loosened dirt particles and Contamination with a suction device similar to one Vacuum cleaner before. The suction can both during the actual cleaning process so the application of plant parts to be cleaned with the particle beam as well afterwards or alternating with the actual one Cleaning process is carried out by the particle beam.

At the beginning, the good insulation properties of the mixture of ambient air, compressed gas, dry ice, moisture and detached dirt particles were described. Since they depend on a large number of parameters, they are difficult to quantify. Experimental investigations by the inventor show, however, that even with a relative air humidity of 90%, the described method and the device according to the invention enable safe cleaning of 400 kV systems, provided the amount of dry ice particles in the compressed gas is at least 50 g per cubic meter of compressed gas , the humidity of the compressed gas is so low that the (pressure) dew point of the compressed gas is lower than 20 ° C (minimum pressure of the compressed gas 1.5 bar), and the average ratio of surface area to volume of the dry ice particles is greater than 0.2 mm Is ^-1 .

So far, the description has always been from cleaning staff the speech. However, the invention is to be understood that not only people are considered as cleaning staff but also robots and handling machines or more generally automated cleaning systems. Usually then of course the security aspect regarding the respective Automata less critical than humans and the aspect of Plant safety of the plant to be cleaned occurs in the Foreground. The required minimum distances are in Germany then no longer necessarily through the VDE standard VDE 0105 specified, but based on the requirements the system to be cleaned and the hazard potential for the machine. It is not just insulation properties that play a role here but e.g. also EMC properties (electromagnetic Compatibility) matter. As handle HG or hand rest HG 'are then the mechanical connecting elements between the robot or machine and the spacer and / or their attachment to the spacer to watch.

If so far in this description without further specification of high voltage, there are always electrical ones To understand direct or alternating voltages above 1 kV. The invention has been described in more detail above Described embodiments. However, the invention is so to understand that even minor modifications and alterations, as obvious to an average professional are to fall within the scope of the invention.

Claims (24)

1. Cleaning method for cleaning the surface of high voltage carrying installation component parts or of component parts in high-voltage carrying installations comprising the following steps:

   a two-phase jet consisting of a pressure gas as carrier medium and carried dry-ice particles is generated in a jet generator (SG) and is guided to a jet emitting opening (SA) where it leaves into the air,

   the jet leaving the jet emitting opening (SA) is directed to the surface to be cleaned,

   it is guaranteed that the cleaning personnel always keeps away a minimum distance from the jet emitting opening (SA) that corresponds to the minimum distance to the high-voltage carrying component part required for personal protection and/or installation safety by means of an at least partly electrically isolating distancing means (L, SFR) that is attached to the jet emitting opening and that comprises or is connected to a handhold (HG) or a hand rest (HG') and, if necessary, control elements for the cleaning personnel.
2. Cleaning method as claimed in claim 1 characterized in that the humidity content of the pressure gas is monitored before and/or during the cleaning process and that when exceeding a predetermined limit value the cleaning process is not started at all or it is interrupted, respectively.
3. Cleaning method as claimed in claims 1 or 2 characterized in that the humidity content of the ambient air is monitored before and/or during the cleaning process and that when exceeding a predetermined limit value the cleaning process is not started at all or it is interrupted, respectively.
4. Cleaning method as claimed in claims 1 to 3 characterized in that the electrical isolation properties of the distancing means (L, SFR) are monitored and that the cleaning process is not started at all or it is interrupted, respectively, when the electrical isolation falls below a predetermined threshold value or when the electric current flowing through at least a part of the distancing means exceeds a predetermined threshold.
5. Cleaning method as claimed in claims 2 to 4 characterized in that the prevention of start of the cleaning process or the interruption of the cleaning process, respectively, are effected by an interruption of pressure gas supply.
6. Cleaning method as claimed in claims 1 to 5 characterized by a removal of the dirt particles and contamination loosened or blast off by the particle beam by means of suction during the cleaning process and/or afterwards.
7. Cleaning method as claimed in claims 1 to 6 characterized by the particle jet being generated or guided in a way that its direction when leaving the jet emitting opening (SA) is not collinear to the privileged direction of the distancing means (L, SFR):
8. Cleaning method as claimed in claim 1 to 7 characterized in that the dry-ice quantity in the pressure gas amounts to at least 50 g dry ice per cube meter pressure gas and that the humidity of the pressure gas is so low that the pressure dew point of the pressure gas is below 20 °C.
9. Cleaning device for cleaning the surface of high-voltage carrying installation component parts or of component parts in high-voltage carrying installations with the following characteristics:

   the cleaning device comprises an internal pressure-gas generator (DGG) that produces a pressure gas with a pressure above atmospheric or it comprises a pressure gas inlet (DGA) for externally supplying a pressure gas with a pressure above atmospheric,

   the cleaning device comprises a dry-ice reservoir (TV) with dry-ice particles and/or it comprises a particle generator that produces dry-ice particles,

   the cleaning device comprises a jet generator (SG) generating a two-phase jet consisting of the pressure gas as carrier medium and dry-ice particles carried by the pressure gas, said jet generator therefore being connected via a pressure-gas line (DGL) to the pressure-gas generator (DGG) or the pressure-gas inlet (DGA), respectively, for pressure-gas supply and said jet generator being connected to the dry-ice reservoir (TV) or the particle generator for dry-ice particle supply,

   a guidance (SF) is connected to the jet generator (SG) guiding the particle jet from the jet generator (SG) into the air via a jet emitting opening (SA), and

   the cleaning device comprises an at least partly electrically isolating distancing means (L, SFR) that at least comprises or is connected to a handhold (HG) and/or a hand rest (HG') and, if necessary, control elements for the cleaning personnel, and a jet emitting opening (SA) being positioned at the end of the distance means or nearby whereby the length of distance means (L, SFR) measured from the handhold (HG) or the hand rest (HG') is designed higher than or equal to the minimum distance to the high-voltage carrying component part required for electrical personal protection and/or installation safety.
10. Cleaning device as claimed in claim 9 characterized in that the distance means is a lance at least partly made of an isolating material and that the jet generator (SG) is attached to the end of said lance, if necessary, with an angular deviation.
11. Cleaning device as claimed in claim 9 characterized by the distancing means (SFR) additionally being employed for jet guidance.
12. Cleaning device as claimed in claims 9 to 11 characterized by the integration of the jet generator (SG) into the distancing means (L, SFR).
13. Cleaning device as claimed in claims 11 or 12 characterized by a distance means that is a, if necessary, slightly cone-like widening jet guiding tube (SFR) comprising at its one end the jet generator (SG) or there being connected to the jet generator and the other end of said distancing means forming the jet emitting opening (SA).
14. Cleaning device as claimed in claim 13 characterized by the jet guiding tube (SFR) comprising a jet deflection near its end shortly before the jet emitting opening (SA).
15. Cleaning device as claimed in claims 9 to 14 comprising a shut-down unit (V) and a humidity sensor (DFS) that is positioned in the pressure-gas supply between the pressure-gas generator (DGG) or the pressure-gas inlet (DGA), respectively, and the jet generator, or that is positioned in the particle jet in the jet generator or in the guidance (SF) or that is positioned directly before or behind the jet emitting opening (SG), said humidity inhibiting the start of the pressure-gas supply and/or effecting an interruption of the pressure-gas supply by means of the shut-down unit (V) whenever a predetermined humidity limit value is exceeded.
16. Cleaning device as claimed in claims 9 to 15 comprising an ambient air humidity sensor (LFS) measuring the humidity of the ambient air.
17. Cleaning device as claimed in claim 16 comprising a shut-down unit (V) that effects an interruption of pressure-gas supply and/or inhibits the start of pressure-gas supply as soon as the ambient air humidity sensor indicates a predetermined humidity value level being exceeded or the condensation of water vapor.
18. Cleaning device as claimed in claims 9 to 17 comprising an isolation monitoring unit monitoring the isolation properties of the distancing means and that when the isolation power falling below a predetermined limit value emits a warning to the cleaning personnel or effects an interruption of the pressure gas supply and/or inhibits the start of the pressure-gas supply or inhibits an other essential component of the cleaning device or that powers down the installation component part to be cleaned.
19. Cleaning device as claimed in claim 18 characterized by the isolation monitoring unit comprising an electrode (IME1) arranged at or inside the distancing means (L, SFR), via that the leakage current to ground is measured.
20. Cleaning device as claimed in claims 9 to 19 comprising an additional suction unit for removal of the dirt particles and contamination loosened or blast off by the particle beam by means of pneumatic suction.
21. Cleaning device as claimed in claims 9 to 20 characterized in that the quantity of dry ice in the pressure gas amounts to at least 50 g dry-ice per cubic meter pressure gas and that the humidity of the pressure gas is so low that the pressure dew point of the pressure gas lies below 20 °C.
22. Application of a cleaning device as claimed in claim 9 to 21 for surface cleaning of installation component parts carrying an electric high-voltage or of installations component parts in installations carrying a high-voltage.
23. Application of a particle jet consisting of a pressure gas as carrier medium and dry-ice particles carried by the pressure gas for cleaning the surface of installation component parts carrying a high-voltage or of component parts in high-voltage installations whereby the humidity of the pressure gas and/or ambient air humidity are monitored and when exceeding predetermined limit values an interruption of the cleaning process is effected or the start of the cleaning process is inhibited, respectively.
24. Application of a particle jet consisting of a pressure gas as carrier medium and dry-ice particles carried by the pressure gas for cleaning the surface of installation component parts carrying a high-voltage or of component parts in high-voltage carrying installations whereby the dry-ice quantity in the pressure gas amounts to at least 50 g dry-ice per cubic meter pressure-gas and the humidity of the pressure gas is so low that the pressure dew point lies lower than 20 °C.

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