EP0631849B1 - Method and device for cleaning surfaces - Google Patents

Abstract

A cleaning method with a corresponding device provides, for the blast-cleaning of surfaces (1), in particular façades, a treatment region (2) with an air curtain (33) and an exhausting device (27-29, 18). The treatment region (2) adjoins, on one side with a contact opening (30), the surface (1) in leaktight fashion and encompasses, on the other side, a working opening (31b) through which the cleaning personnel (9) can guide the blast-cleaning nozzle (10) with visual contact over the surface (1) to be cleaned. The air curtain (33) is configured in such a way along the working opening (31b) that no dust or abrasive escapes from the treatment region (2) through the working opening (31b). <IMAGE>

Description

The invention relates to a method according to the Generic term of Claim 1 and a device according to the preamble of claim 5. This prior art is known from EP-A-0 365 707.

Facades caused by environmental factors, such as the deposition of Soot particles, or dirty due to unwanted paint application are by mechanical grinding methods, preferably but cleaned with a dry jet. The grit exists preferably made of tiny round elastic glass beads sprayed onto the surface to be cleaned with a slight twist and erase the layer of dirt. The Blasting material and the dirt particles are removed by a vacuum system aspirated and fed to a dedusting system, the separates the blasting material from the dirt. To dust generation and to minimize the emission of blasting material to the environment the blasting and suction in a closed to the outside Space that is on the only open side close to the one to be processed Surface is applied.

The cleaning staff must check the effect of the jet, to keep the beam on soiled areas for so long, until the desired cleanliness is achieved. To that To provide necessary visual contact, two solutions are known. The first solution provides that the enclosed space is sufficient is large to accommodate the cleaning staff. The second solution chooses the size of the enclosed space small that it was held in the hand of the cleaning staff and can be guided over the surface.

The first solution has the disadvantage that the cleaning staff receiving, work space which with its open side abuts the facade and is moved in sections, very much big and therefore extremely heavy. To move along a crane truck is used on the facade, on its jib the work area is suspended. From underwriting The hanging type of attachment is for a manned Work space only with a special and very expensive Crane truck permitted. In addition, there is a high concentration of dirt and blasting material in the workroom a danger to the eyes and Respiratory tract of cleaning staff. Only by wearing Safety glasses, protective masks and protective suits can pose a health risk be reduced to a permissible level. The Protective measures do not offer complete protection and are also hinders work.

When working in a closed work space due to of insufficient daylight and due to the high A considerable visual impairment. The visual impairment is the reason that the cleaning result too little can be controlled. Also unsatisfactory on closed work space is the lack of direct communication to the outside world, especially for crane truck guidance. Intercoms required due to the high level of noise can only be used unsatisfactorily in the work area. Isolating the cleaning staff in an extremely uncomfortable way Working climate worsens the work ethic and thus also the efficiency of the cleaning process. In addition, the closed work space a great deal of equipment and to staff, so that the cleaning costs are very high.

The second solution has the disadvantage that the jet nozzle and enclosed space receiving the suction connection, or Work box, hand-held and guided along the surface must become. The necessary freedom of movement along the Surface does not leave a satisfactory seal on the opposite the surface open side so that dirt particles and Emit blasting material and have a negative impact on the environment, especially the health of the cleaning staff. The The cleaning jet can hit the surface in the closed Space can not be observed, so the targeted Editing dirt spots is not possible enough. Also to check the cleaning effect of the work box be moved first, making the cleaning process very cumbersome becomes.

The object of the invention is now a method and to describe a device which is efficient cleaning thereby enable the cleaning staff to do the necessary Visual contact with the cleaning jet and the necessary manipulation of the beam without sacrificing the environment and the cleaning staff an increased concentration of dirt and blasting material are exposed.

The invention is defined by claims 1 and 5. It is envisaged that a treatment area is used with at least one suction opening, the both on a contact side against the surface to be machined for jet cleaning as well as on one of the surfaces opposite front boundary surface for manipulation and viewing purposes, is at least partially open. Laterally the treatment area is preferably at least three but four, lateral boundary surfaces that are transverse to the surface and are arranged to the front boundary surface, at least partially locked to the outside. On the contact page is a Discharge of blasting material and dirt particles through a sealing device, which encloses the opening on the contact side and close to the surface. To prevent particles from escaping from a working opening in the Preventing front boundary surface is at least in one Part of the treatment area is a gas flow, essentially excited parallel to the surface.

The gas flow preferably comprises at least one gas or Air curtain which emanates from an entry device and extends into the area of the at least one suction opening. The entry device is at least along one arranged lateral boundary surface, comprises at least one Line nozzle and / or several point nozzles and is by compressed gas, but preferably fed compressed air. The arrangement of the Entry device and the at least one suction opening is chosen in particular so that the air curtain runs along extends the front boundary surface and the working opening against an escape of air that is between the curtain and of the contact surface.

About turbulence and long debris and blasting time to avoid in the treatment area preferably between the air curtain and the one to be cleaned Surface or the contact side of a blasting material suction flow excited. This flow is already emerging, at least in part by entering the cleaning jet and vacuuming. However, it is preferably caused by incoming false air, if necessary but also by injected gas, in particular Compressed air strengthened or evened out. That is preferable The desired flow pattern looks essentially in the entire treatment area a single one, essentially to the surface parallel, main flow direction. Large swirls with significant backflows must be avoided. The flow rate is maximum in the center of the air curtain and decreases on average towards the surface.

Of course, the flow in the exit or jet area of the Cleaning jet essentially only in the direction of the jet handed out. But it is actually one local disturbance of the global flow in the treatment area. For Cleaning, the cleaning jet is directed against the surface. Already after bouncing off the surface Jet flow destroyed and the remaining cross to the flow local flow components aligned in the treatment area and turbulence is carried away by the global flow.

The air curtain and the parallel suction flow are formed through the interaction of the incoming compressed air, and if necessary the false air, as well as the suction power and the arrangement the at least one suction opening. To the one you want to maintain a uniform flow pattern occurs incoming air, compressed air and / or false air, in the area a first lateral boundary surface in the treatment area and is through at least one suction opening in the area suctioned off a second lateral boundary surface, wherein the first and the second boundary surface lying opposite one another are arranged. The suction volume throughput is like this set, or if necessary, but by a control device regulated so that it essentially always at least the sum of the uncompressed volume entry through the entry device and the jet nozzle corresponds. Preferably but it is at least larger at times and leads to false air from. False air can also exist between the sealing device, which encloses the opening on the contact side, and enter the treatment area on the surface.

It is for regulating the flow through the treatment area if appropriate, at least one physical Size, such as the pressure or one of the blasting material concentration dependent size, using at least one sensor capture. In a near surface of the at least one Extraction opening in the remote zone of the treatment area the risk that due to a weak suction flow a high particle concentration and therefore poor visibility to adjust. The effective visibility can can be detected with an optical sensor, for example. Pressure measurements provide information on the flow situation detected. The suction power can be adjusted according to the measured values and / or the inflow of incorrect and / or compressed air be managed.

Through the use according to the invention of one to be cleaned Surface of the upstream, air-flowed treatment area, the cleaning staff can change the jet nozzle through a Lead the work opening unhindered in the treatment area and at the same time observe the effect of the cleaning jet. Here neither the personnel nor the environment is exposed to blasting material and / or dirt particles impaired.

The device required to carry out the method is lightweight and can be used to clean facades on a commercial Lift, for example on a by means of a swiveling telescopic arm can be positioned in a large area Work platform to be attached. Because the treatment area when cleaning facades essentially vertically is aligned, the air inlet device is preferred at an overhead and the at least one suction opening on an underlying lateral surface arranged. As a result, the blasting material is not only by Flow in the treatment area, but also by gravity moved against the at least one suction opening.

Via a blasting material line is from one on the ground Compressor fed the cleaning jet nozzle, being used for control the cleaning jet, or the compressor preferably a control line from an operating handle at the Jet nozzle to the compressor is provided. The one for the air curtain and possibly necessary for the blasting material suction flow Compressed air is supplied by the same or another compressor a compressed air line led to the entry device. For Connection of the at least one suction opening with one on the floor arranged suction unit is another line, preferably a flexible hose, a metal spiral and a Includes plastic jacket provided.

By using a device according to the invention together with a work platform that can be operated from above, facade cleaning can be done by a single person be carried out. The labor costs and equipment costs are extremely small. In addition to this economic advantage is that Quality of the job compared to the known closed Workrooms are significantly better and it can be used with a larger one Motivation of the cleaning staff can be expected.

It has been shown that a treatment area according to the invention not only beneficial together with a cleaning jet, is new and inventive. Even with mechanical processing a surface where particles are released, So when grinding the surface with belt or Disc grinding machines, it is expedient to use an inventive one Treatment area with an air curtain and a suction device to use. This can release dust to the environment and protect staff.

The application of the method according to the invention is not limited to the cleaning of facades is limited, but can for example also in workshops for machining workpiece surfaces be used. This prevents dirt and / or Exit the blasting particles into the workshop. The one to be processed Surface can be on a contact surface or inside of the machining area. Will she be in Arranged inside, there is an end wall instead of the contact opening intended. The treatment area is covered by a processing chamber with only one working opening is formed becomes. The known processing chambers are essentially completely closed to the outside and for guidance of the implement are only attached to hand openings gloves provided in the processing chamber. At These devices according to the prior art are freedom of movement of the cleaning staff severely restricted. A Treatment area according to the invention now has the great advantage that the opening of work is only marginally restricted Manipulation becomes possible without being essential Quantities of dust emerge from the treatment room.

Fig. 1:

Ansicht einer Anordnung mit einer höhenserstellbaren Arbeitsplattform mitsamt Fassadenanschlussteil und mit einem Kompressor sowie einer Aufbereitungsanlage für im Trockenstrahl eingesetztes Strahlgut.

Fig. 2:

Vertikalschnitt durch die Arbeitsplattform und den Behandlungsbereich.

Fig. 3:

Vertikalschnitt durch den oberen Endbereich des Fassadenanschlussteiles.

Fig. 4:

Behandlungsbereich mit Abschlusswand und getrennter Luftzirkulation für den Luftvorhang und das Absaugen.

Fig. 5:

Seiten- und Frontansicht einer Dichtungsvorrichtung mit vorstehenden elastischen Anschlussfortsätzen.

The drawing explains the invention using a schematically illustrated embodiment.

Fig. 1:

View of an arrangement with a height-adjustable work platform including facade connection part and with a compressor and a processing system for blasting material used in the dry jet.

Fig. 2:

Vertical section through the work platform and the treatment area.

Fig. 3:

Vertical section through the upper end area of the facade connection part.

Fig. 4:

Treatment area with end wall and separate air circulation for the air curtain and suction.

Fig. 5:

Side and front view of a sealing device with protruding elastic connection extensions.

1 shows the use of the method according to the invention when cleaning facades. A connecting to a facade 1 cuboid treatment area 2 is by a housing 3 at least partially delimited. The housing 3 includes essentially a frame 4 and attached to it, transversely lateral boundary surfaces 5 and at least one sealing element 6, the lateral boundary surfaces connects and lies close to the facade. In a front boundary surface 7 of the housing 3, which the facade 1 opposite, a work opening is provided. The Housing 3 is attached to a position-adjustable work platform 8, from which the cleaning staff 9 a jet nozzle 10 or another implement through the work opening within the at least one sealing element 6 can be directed to the machined areas of the facade 1.

The work platform 8 is preferably at the free end of a a horizontal axis 11 pivotable telescopic arm 12 a Lifting device 13 attached. The cleaning staff 9 can Position of the work platform 8 and thus the treatment area 2 adjust via a control panel 14 along the facade 1 and clean the entire facade 1 in sections. That for The blasting material required is used to generate the cleaning jet Compressed air through a compressor and blasting device 15 which is parked near the lifting device 13, via a Blasting material line 16 led to the blasting nozzle 10. Parallel to Line 16, a control line 17 is arranged and via a Control unit 22 and a compressor cable 23 with the compressor the device 15 connected. The control line 17 enables it to the cleaning staff 9 by means of a connected to it Actuator, the compressor of the device 15 and thus to regulate the jet.

The blasting material is removed from the treatment area 2 by at least one arranged on the lower lateral boundary surface 5 Suction opening and a flexible hose connected to it sucked to a recycling unit 19. The recycling unit 19 essentially comprises a suction unit and a Dedusting device that carries the blasting material away Separates dust. The blasting material passes through a line 20 from the recycling unit 19 for reuse in the cleaning jet into the device 15.

From the compressor of the device 15, or possibly from a second compressor, a compressed air line 21 leads to Housing 3. The compressed air supplied in it becomes formation an air curtain and possibly to reinforce one Blasting material suction flow used in treatment area 2. Around if necessary, the suction power always the supplied air quantities The control unit 22 can be adapted via a Connection cable 24 also connected to the recycling unit 19.

2, the housing 3, which is the treatment area 2 surrounds, by means of connecting elements 25 and 26 on the Work platform 8 attached. The connecting elements are preferably 25, 26 designed so that the housing 3 with little Workload can be attached and removed. Thereby the work platform 8 remains for other tasks can be used unchanged. The housing 3 preferably comprises two vertical frame parts adjoining the platform 8 4a, the top and bottom with horizontal against the facade 1 leading frame parts 4b are connected. Between the upper ones and if necessary also between the lower ones Parts 4b are aligned horizontally parallel to the facade 1 Frame parts 4c provided. Between the lower parts 4b is possibly only a grate 27 and adjoining it at the bottom a funnel 28 is provided. Since the funnel 28 attached to the flexible hose 18 and thus connected to the suction unit is, the passage openings of the grate 27 form the suction openings 29. The grate 27 holds large foreign parts, such as Tools, back in the treatment area.

Above the upper frame parts 4b and 4c is an upper boundary surface 5a attached. Laterally on the frame parts 4a and 4b are arranged lateral boundary surfaces 5b, so that the Treatment area 2 laterally, above and below through the wall parts 5b, 5a and 27 is limited. Connects to these wall parts on the side of the facade 1 around a contact opening 30, the access from the treatment area to a facade cutout leaves at least one sealing element 6. Execution 2 comprises two round hollow profiles arranged side by side made of elastic material, such as rubber or plastic. To prevent particles on the bottom edge surface assigned, seal 6 remain an inclined sealing surface 54 is provided. Preferably but a sealing device 6 with at least one compressed air fed air chamber system with at least one preferably but two dining openings and possibly at least one the bursting of a sealing element preventing pressure relief valve used.

If necessary, also on facade parts with larger unevenness to achieve a sufficient seal, for example the air chambers near the facade are less crowded. In order to the seal 6 even in the case of strongly curved facade parts, especially in the case of columns, around the contact opening 30 the facade 1 abuts, in addition to various sealing profiles also bellows and / or lamella and / or brush-like Sealing elements are used. Another beneficial one Execution of the sealing device 6 is further based on 5 described.

In addition to the suction openings 29 can also in the area of the side Boundary surfaces 5b at least one suction opening 29 ' be provided. Preferably on at least one side the contact surface 30 at least one substantially parallel suction channel 52 running to the surface with a slot opening 29 'preferably along the lateral boundary surface slidably attached to guide elements 53. By the provision of suction openings 29, 29 'is essentially round around the contact opening 30, can be prevented at poor sealing by the sealing device 6 large amounts of dust and jet particles escape. Of the Suction channels 52 lead suction lines 52 'to a connection device to the flexible hose 18 or directly to Recycling unit 19.

The one opposite the contact opening 30 or the work platform facing, front boundary surface 31 is preferred closed in a lower region by a front plate 31a. The working opening is in the upper region of the front edge 31 31b so that the cleaning staff 9 the cleaning jet nozzle 10 essentially under visual contact in the entire area of the contact opening 30 via the facade 1 can lead. An emerging cleaning jet 32 strikes the facade and removes the unwanted layer. The Blasting material and the dirt particles flow away from the facade 1 and arrive at least in part due to the suction and the Gravity against the suction openings 29 below.

For the discharge of blasting material and / or dust through the working opening To prevent an air curtain 33 in the treatment area 2 directly inside the working opening 31b on the entire width of the opening is provided. This air curtain 33 is due to the interaction of one on the upper boundary surface 5a attached air intake device and suction through the suction openings 29. The air intake device comprises at least one line nozzle 34, or a number of point nozzles arranged on a line, which in the are aligned substantially parallel to the work opening and one directed downwards along the front boundary surface Generate air flow. The air nozzles 34 are through the Compressed air line 21, which preferably in the housing 3 along of a frame part 4a leads, fed and are optionally designed as Venturi nozzles.

Between the air curtain 33 and the contact opening 30 should not a flow structure with large vortices, but one if possible Develop a uniform blasting material suction flow. Around To achieve this, if necessary, bad air and / or Compressed air in the area near the facade behind the air curtain 33 will be introduced. For admitting false air, for example at least one false air opening 35 in the upper one Boundary surface 5a can be provided. The false air opening 5a is optionally designed as a pressure reduction valve, or is adjustable via a false air control device.

An embodiment according to FIG. 3a provides that the air inlet device in addition to the at least one air nozzle 34 for the air curtain 33 also at least one additional inlet nozzle 36 and a distribution device 37. The inlet nozzle 36 is in the area of the upper boundary surface 5a between the air nozzle 34 and the contact opening arranged and excited together with the Suction a uniform blasting material suction flow. To the nozzle 36 can consist of several point or line nozzles, or as a surface nozzle, for example made of porous material consist. Due to the type of formation of the nozzles 34 and 36 as well the appropriate distribution of the compressed air by means of the distribution device 37 on the nozzles 34 and 36 can be used throughout the treatment area 2 a desired flow structure can be excited. In particular, a distribution control can be provided which regulates the distribution depending on the company and in addition for example via the control line 17 with the control unit 22 is connected.

The embodiment according to FIG. 3b looks between the air curtain 33 and the contact opening 30, preferably in the area of upper boundary surface 5a, at least one sensor 38 in front of the the pressure, or preferably one of the particle concentration dependent size, especially with an optical measuring method, certainly. The sensor is connected to an evaluation and control device 39 connected, which in turn preferably with the distribution device 37 and optionally via a line 17a and 17 is connected to the control unit 22. So it is possible both the air entry through the air nozzles 34 and 36, as well as the suction power, and possibly the performance of the Jet nozzle automatically depends on the measured value of the sensor change.

According to FIG. 4, a further embodiment provides that a surface 1 'to be cleaned not at a contact opening 30, but is arranged in the treatment area 2 and that instead the contact opening 30 on the housing 3, an end wall 40 connects to the lateral boundary surfaces 5. In the Surface 1 'is the surface of a workpiece 41 that of a mounting device 42 in the treatment room 2 is held. The holding device 42 comprises preferably an arm 44, which at one end via a guide device 43 is attached to the housing 2 and the other End a preferably rotatable fastening device 45 for Attaching the workpiece 41 carries. Around every surface section of the workpiece 41 is accessible from the working opening 31b to make the workpiece 41 in the treatment area to be turned around.

For feeding a suction flow 48 in the area of the to be cleaned Surface 1 'is an inlet nozzle above the workpiece 41, preferably a surface nozzle 36a, for example made of porous Material consisting, arranged. The surface nozzle 36a is via a feed line 46 and a distributor 47 with gas, in particular fed with compressed air. To discharge the suction flow 48, preferably under a grate 50, is at least one first suction opening 49 arranged.

Is directly connected to the working opening 31b for generation the air curtain on a boundary surface 5 the air nozzle 34 and on an opposite boundary surface 5 at least a second suction opening 51 is arranged. By connecting a second suction device to the second suction opening there is now the possibility with two essentially to work separate flow circulations. Here leads the first flow circulation dirt particles and possibly Blasting material from treatment area 2 and the the second circulation is the air curtain. In this version the air of the air curtain does not have to pass through the dedusting system and the two flows 33 and 48 can optionally in the treatment room 2 in different Directions, especially in opposite or essentially perpendicular directions, excited will. In addition, different gases can be used for both flows be used.

The two separate flow circulations can also be used an embodiment without end wall 40 advantageously used will. 4 could be the work opening 31b also in the upper boundary surface 5a, and the air curtain Provide horizontally along this upper boundary surface 5a. The first circulation flow could also possibly be used be aligned horizontally. It turns out that the respective Cleaning problem adapted, a variety of inventive Embodiments can be provided.

5 shows a preferred embodiment of the sealing device 6, which is also suitable for facades with a variety of elements protruding from the level of the facade, such as ledges and heels, a good seal of the treatment area 2 guaranteed to the outside. The inventive idea, the solution is based on the fact that in the above Contact surface 55 of the sealing device 6 the transmission limited to small areas by surface forces should. To do this, one must preferably be made of elastic foam existing contact layer 56 against the contact surface 55 in closely adjoining individual foam extensions 57 can be divided, which are pressed together individually can. There are none between different extensions 57 Transfer surface forces and the contact surface 55 can thus abruptly connect to facade heels 58. At a contiguous contact surface 55 would also over Paragraphs 58 protruding from the facade 1 continuously trained so that 58 openings on both sides of such paragraphs between the facade 1 and the sealing device 6 would exist.

The extensions 57 are essentially at least in a longitudinal path 59 along the sealing device 6, or around the contact opening arranged. Since there is an extension 57, which is currently in the Area of a heel edge is not close to it, are as shown in Fig. 5b, in particular several longitudinal tracks 59 preferably arranged side by side so that the above Extensions 57 different tracks offset from each other are. Optionally, the extensions are also provided 57 different tracks 59 different in the longitudinal direction train long. By moving and the different Length of the extensions 57 is that extension sides in small intervals occur, so that no paragraphs, or only very small openings arise.

The contact layer 56 can optionally also be tubular be constructed. A low pressure is built up inside, so that the chamber-shaped extensions 57 the desired deformability receive. The contact layer is preferably on one belonging to the sealing device 6, with compressed air, in particular High pressure, filled hose body 60 attached. Of the Like the contact layer 56, the tubular body 60 can be made of different sections exist. To replace the contact layer 56 easy to enable, is preferred for attachment a Velcro system is provided. Possibly is also used to attach the at least one hose body 60 a Velcro fastener is provided on the boundary surface 5.

Claims (10)

1. A method for treating surfaces by at least one operational implement taking particles off, the treatment being effected within a treating region (2) which comprises said surface (1) and which is laterally closed to the exterior, at least in part, by at least three lateral boundary surfaces (5) oriented transversely to said surface (1), said particles being sucked off the treating region by a suction device (28-29, 18, 19, 52) at least in a partial region of at least one of the lateral boundary surfaces (5) and at least in part from the bottom side of the boundary surfaces through at least one opening (29) thereof, characterised in that an operator (9) may freely move under sight contact an operational implement (10) through an operation opening (31b) located in a frontal boundary surface (31) opposite said surface (1) within the treating region (2), and that at least one gas stream (33) is provided substantially parallel to said frontal boundary surface (31) at least in a part of said treating region (2).
2. Method according to claim 1, characterised in that said operational implement produces a cleaning jet (32) of fine grained jet particles and a gas and/or that

   a) the gas jet leads as a gas curtain (33), but preferably as an air curtain (33), from a gas or air inlet arrangement (34, 36, 37), which supplies gas or air at least along a part of a lateral boundary surface, to a suction device (28-29, 18, 19), the gas or air curtain (33) substantially preventing exit of particles from the treating region (2) in the region of the operation opening (31b), and being preferably arranged along said front boundary surface (31) to this end, and that in particular

   b) a particle exhaust flow is provided between said gas or air curtain (33) and said surface (1) which is preferably generated by suction and the supply of said cleaning jet, but optionally also by inflowing by-padded air and/or a gas pressed in, particularly pressurised air, and that optionally

   c) the suction volume through-put is set, preferably controlled, in such a manner that it corresponds substantially always to at least the sum of the uncompressed volume supply through said gas inlet arrangement and the jet nozzle, but is preferably larger at least temporarily, thereby discharging by-padded air and/or further gas pressed in.
3. Method according to claim 1 or 2, characterised in that at least one physical value, such as pressure and/or a particle concentration dependent value, is measured within the treating region (2), preferably near said surface and remote from said suction device (28-29, 18, 19), the suction performance and/or said gas flow being controlled as a function of said at least one measured value.
4. Method according to any of claims 1 to 3, characterised in that said treating region (2) is displaceable along a substantially vertical surface, such as a facade wall, its lateral boundary surfaces (5) sealingly joining said surface (1) when part of the surface is cleaned.
5. A cleaning device for carrying out the method according to claim 1, which comprises a housing (3) for delimiting a treating region (2) and at least one operational implement (10) for taking particles off a surface (1), said housing (3) being laterally closed to the exterior, at least in part, by at least three lateral boundary surfaces (5) oriented transversely to said surface (1), thus, containing the surface (1) to be cleaned, and at least one suction device (28-29, 18, 19) being located, at least in part, at the bottom side of the lateral boundary surface (5) and including there at least one opening (29), characterised in that

   an operation opening (31b) is formed in a front boundary surface (31) opposite said surface (1) in such a manner that said operational implement (10) is freely movable through this opening in said treating region (2) under sight contact by an operator (9), and

   a gas inlet arrangement (34, 36 37) is provided, arranged along at least part of a lateral boundary surface, and generates, together with a suction device, a gas flow substantially parallel to said front boundary surface (31), thus substantially preventing exit of particles from said treating region (2) within the region of said operation opening (31b).
6. Cleaning device according to claim 5, characterised in that said operational implement comprises a blasting nozzle (10) in communication with a first compressor and a source of blasting material (19), from which a cleaning jet (32) of fine grained blasting particles and a gas is discharged, said gas inlet arrangement (34, 36 37) being in communication with a second compressor and comprising either a first linear nozzle (34) or a plurality of arrayed first spot nozzles through which pressurised gas, preferably pressurised air, is blown into said treating region (2), said linear nozzle (34) or said array of spot nozzles being situated in a first distance to said front boundary surface (31) substantially parallel to said front boundary surface (31) to generate a areal gas curtain (33) which extends preferably immediately along said front boundary surface (31).
7. Cleaning device according to claim 6, characterised in that at least one of the following characteristics is provided,

   a) at least one supply of by-padded air (35) and/or at least a second gas nozzle (36) pertaining to said gas inlet arrangement (34, 36 37) is provided in at least a second distance from said front boundary surface (31) at the side of the gas curtain which is averted from said operation opening (31b) to cause a particle suction stream, wherein said gas inlet arrangement (34, 36 37) comprises optionally a controllable distribution device (37) for mutual adaptation of the gas streams through said first and second nozzles (34, 36) and/or at least a first or second nozzle (34, 36) is formed as a venturi nozzle,

   b) the lateral boundary surfaces (5) comprise elastic contact members, preferably lamellae or sections of plastic or rubber, in particular hollow sections, such as round sections, within the region of a contact side (30) engaging said surface (1) to achieve a sealing engagement with said surface (1), particularly with protruding elements or with a bent surface, such as a column surface, about two of them being fastened in an adjacently joining manner and being optionally filled with pressurised air and/or members of elastic foam material arranged along at least one longitudinal path, their free ends projecting towards said surface,

   c) an end wall (40) that closes said treating region (2) is arranged at the side of the lateral boundary surfaces (5) opposite said front boundary surface (31).
8. Cleaning device according to claim 6, characterised in that the suction device (28-29, 18, 19) comprises at least one funnel-shaped connecting portion (28) joining to that lateral boundary surface (5), preferably to a grating, which is opposite the gas inlet arrangement (34, 36 37) and communicates with a suction assembly (19) through a suction tube (18), the suction performance of said suction assembly (19) optionally being adjustable by control means (22), said control means (22) being, in particular, coupled with said first compressor, and optionally also with said second compressor so that said control means (22) adjusts said suction performance in such a way that it corresponds substantially always to at least the sum of the uncompressed volume supply through said gas inlet arrangement (34, 36) and the blasting nozzle (10).
9. Cleaning device according to claim 8, characterised in that at least one sensor (38) for measuring a physical value, such as pressure and/or a particle concentration dependent value, is arranged within the treating region (2), preferably near said surface and remote from said suction device (28-29, 18, 19), which is preferably coupled with said control means (39, 22) so that said suction assembly (19) and/or optionally said first or second compressor may be controlled as a function of at least one respective measuring value, wherein, in particular, at least one coupling is provided between said control means (39, 22) and said controllable distribution device (37) in order to control said gas curtain (33) and the suction stream.
10. Cleaning device according to any of claims 6 to 9, characterised in that a first suction device is provided for sucking dirt particles and, optionally, blasting material, and a second suction device is assigned to the gas curtain (33) so that two separate circulations of flow are generated which, optionally, extend in different directions, particularly in opposite directions, within the treating space (2).

Images