WO2015035479A1 - Method and set for cleaning surfaces using dry ice in combination with abrasive material, acomplete set for cleaning surface and a method of using the set - Google Patents

Abstract

In a method of cleaning surfaces, especially hard surfaces covered with removable materials of all kinds, are removed by dry ice with the addition of abrasive and restoring such as (volcanic powder, brown fused alumina, fused alumina white, mixed corundum, glass beads, glass grit). Method: a stream of compressed air is applied to the surface being cleaned in a safe distance. Before use, compressed air (1) is passed through a container of dry ice and a dispensing device (4) with abrasive material at a temperature of from -70 0 C to -30° C, and granulation of 1.5 to 5 mm. Kit for cleaning surfaces comprises a nozzle mounted on the lance (7) connected to a dry ice dispensing device with wiping materials (5) using special hoses, and air supplied by the compressor (1). Abrasion material is dispensed by the device to dry ice or sprinkle directly to the dry ice (4).

Description

Description:

The object of the invention is a method and set for cleaning surfaces using dry ice in combination with abrasive material, a complete set for cleaning surface and a method of using the set.

Prior Art:

From EP 2008770 is known a method involving extracting dry ice from a reservoir (2) that is dosed by a mixing unit, and is mixed with compressed air. The dry ice is radiated with a separating unit on cleaning surface. Equilibrium is developed between the cleaned surface and the separating unit, where a separating layer is formed on the surface. The separating layer is developed in a thickness of 10 picometer to 120 picometer, particularly 30 picometer to 50 picometer, which is provided as dry ice carbon-dioxide-pellets. The separating unit is provided in form of a fluid.

From CH698563 is known a Cartesian robot for cleaning plant with components at high voltage uses dry ice supplied from a tank (6) to a nozzle (5). The nozzle is attached to a mounting (4) which can swivel about at least one axis (24, 26).

Independent claims are included for: (A) cleaning systems incorporating the robot; (B) a method for cleaning plant with components at high voltage using the systems; and (C) the nozzle.

From DE 102005035433 is known a cleaning device for rails (1) and/or chains has a device (2) to issue solid carbon dioxide movable on the rail, a storage hoider for the solid carbon dioxide and/or a device for creating it. There are issuing jets (3) for the carbon dioxide, and a suction device (6) to remove loosened dirt next to the issuing jets.

From patent specification PL 169486 there is known a method for cleaning indoor electric substations, using the effect of sucking the dirt by the vacuum generated by an industrial vacuum device and reciprocating motion of cleaning devices, in which on the basis of measurements of humidity and temperature graphically on a plane in a rectangular coordinate system (humidity, temperature) there is determined a forbidden area of work and a safe area of work under voltage and afterwards the measurements of humidity and temperature outside the electric substation are taken, then the measurement point with the coordinates based on the difference of the temperatures outside and inside of the substation is set, and if the point is placed in the safe work area, the dust and sediment are removed from the respective elements of the substation equipment.

From patent specification PL 185360 there is known a method for cleaning of indoor electromagnetic devices using liquid cleaning agent. In this method for rated voltage, there is the allowable isolating clearance determined and from air temperature and humidity measurements vertical dimensions, horizontal danger areas and the minimum distance of horizontal close up are set. Comparison of the horizontal close up distance with size of the isolating clearance is made, and then from the distance of close up a spray-gun with adjustable pressure of spraying, under low pressure, hydrodynamic steady stream of hydrophobic liquid of high electric resistance is directed onto the dirty surface, in direction from the top to the down. Afterward, the brush attached to the insulated rod abrades the wet surface mechanically within the safe close up distance.

From the Polish patent application P.296801 there is known a method of cleaning, especially live electrical switch-rooms and cleaning, washing and spraying device for the electrical switch-rooms. The method consists in that an operator stands on an insulating foot-pace wearing insulating rubber boots and insulating helmet with anti- dust screen holding in his both hands secured by insulating gloves a sucking insulating tube and makes with a brush reciprocating movements, whereas the brush adheres to the cleaned surface and sucks in dust and grits under pressure

appropriately higher than 14,3 kPa until dust and dirt are removed, and then, the operator puts dielectric chemical and dissolvent on to the brush and standing on the insulated foot-pace makes reciprocating movements on the surfaces of electric apparatus, devices and installations and cleans the dirt. Next, after the surface is cleaned, the operator sprays the electric apparatus, devices and installations with chemical under pressure, conveniently 4 - 6.2 bars, which at the same time flushes away dissolved dirt and leave a film which secures from dirt and corrosion cleaned surface. A cleaning device consists of vertical fan-filtering system put in electro- insulating case, a dust container and an insulating carriage with an insulating handle. The dust container is connected to a sucking device ended with a brush by means of a sucking and electro-insulating hose and electro-insulating sucking tube. A washing device is a brush with a body having symmetrically drilled sucking holes put between double tufts of bristle on its whole surface connected favourably permanently with the insulating pipe. In a spraying device a compressor is connected by an insulating pressure hose to a check valve of a liquid container, and in turn an outlet of the liquid container, connected with a diffuser touching a bottom of the liquid container, is connected to insulating pressure hose with insulating airbrush. However, this method is very time-consuming. The above mentioned methods of cleaning require

mechanical contact with electric devices what may cause its damage.

There is also known another method for cleaning dirty surfaces using dry ice, in which traditional methods of sandblasting used for cleaning surface from

contaminants, for example covered in lacquer, grease and resin, have been replaced by a method using dry ice in form of pellets.

Because the pellets of dry ice change into gas and sublimate to the atmosphere immediately after streaming, in EP-25969 0 A2, everything that is left is dirt separated from the cleaned surface and the surface itself is not processed

mechanically in any way. This method allows keeping the processed surface properties reduces the amount of chemical residue and shortens the time of cleaning process. In a cleaning device there is a container from which by a funnel the pellets of dry ice are transported to an output hose. Simultaneously an air gun with compressed air creates vacuum, the effect is that the pellets of dry ice are gently sucked in and accelerated to flow velocity of approximately 300 m/s. Thanks to highly efficient nozzles the stream of pellets is "shot out" onto the surface of the cleaned material. Contact of dry ice pellets of the temperature -79[deg.] C with the

contaminants makes them crush, and as a consequence of thermal shock separates it from the cleaned surface. High speed of the second stream of pellets causes complete separation a top layer of the contaminants. Effectiveness of this method is caused by thermal shock and pneumatic effect. In contrary to sandblasting, in this method, the cleaned surface of main material is not disturbed. Immediately after contact with the contaminant, dry ice changes into gas and escapes to the

atmosphere. Using this method there is a possibility to remove all kinds of surface contaminant such as glue, oils, lacquers, grease, bitumen mass, dissolvent, rust, wax, printing ink, silicones, polyurethane foams, food industry contaminants, scale, seizing and many more.

Still there is a need for even more efficient cleaning methods, which are also ecologic, quick and economic.

None of the hereby cited prior is using abrasive material select from volcanic ash powder, mixed corundum, glass beads, or glass grit or combination thereof.

The combination of the dry ice clearing method and abrasive the volcanic ash powder, mixed corundum, glass beads, or glass grit or combination thereof has a surprising synergetic effect, namely that the surfaces to be cleaned are cleaned more effective in shorted time and more economic.

After intensive research the inventor found out that a combination of the dry ice clearing method and abrasive the volcanic ash, mixed corundum, glass beads, or glass grit or combination thereof has 3 surprising synergetic effect, namely that the surfaces to be cleaned are cleaned better in shorted time and thus more economic and ecologique.

The synergetic effect of the new combination of this was surprising. None of the prior art know to the applicant is teaching to combine these two cleaning methods.

Thus the objective problem to be solved is how to modify the classical dry ice method to achieve the above effect.

The solution is the method as laid down in the claims.

The most preferred abrasive material is volcanic ash powder.

These abrasive material is mostly inert and of natural source and present thus no environmental harm. The specially preferred volcanic ash powder is from natural source and thus 100% ecologic and represent no ecologically hazardless and represents no harm.

More than 80% present of the volcanic ash powder used during the cleaning process goes into the atmosphere and to not need to remove. The remaining 20 % of volcanic ash power is simply and easily whipped away and can be collect for a later reuse or a different known use of Vulcan ash powder, like in agriculture or as filler, etc.

These ashes do not need any special after treatment and can without any problems be cleaned away. The washing water containing these ashes does neither need any special treatment. These represent an enormous advantage. After treatment of water is a costly and consumes a lot of energy. Thus the using of the Vulcan ash has not only advantage in the cleaning of surfaces, combined with the dry ice technique, but also has an easy handling and basically not after treatment of the waste water is needed

Vulcan ashes can be easy to be provided and are of low cost.

Volcanic ash is formed during explosive volcanic eruptions, phreatomagmatic eruptions and during transport in pyroclastic density currents.

Explosive eruptions occur when magma decompresses as it rises, allowing dissolved volatiles (dominantly water and carbon dioxide) to resolve into gas bubbles. As more bubbles nucleate foam is produced, which decreases the density of the magma, accelerating it up the conduit. Fragmentation occurs when bubbles occupy ~70-80 vol% of the erupting mixture. When fragmentation occurs, violently expanding bubbles tear the magma apart into fragments which are ejected into the atmosphere where they solidify into ash particles. Fragmentation is a very efficient process of ash formation and is capable of generating very fine ash even without the addition of water.

Volcanic ash is also produced during phreatomagmatic eruptions. During these eruptions fragmentation occurs when magma comes into contact with bodies of water (such as the sea, lakes and marshes) groundwater, snow or ice. As the magma, which is significantly hotter than the boiling point of water, comes into contact with water an insulating vapour film forms. Eventually this vapour film will collapse leading to direct coupling of the cold water and hot magma. This increases the heat transfer which leads to the rapid expansion of water and fragmentation of the magma into small particles which are subsequently ejected from the volcanic vent. Fragmentation causes an increase in contact area between magma and water creating a feedback mechanism, leading to further fragmentation and production of fine ash particles.

Pyroclastic density currents can also produce ash particles. These are typically produced by lava dome collapse or collapse of the eruption column. Within

pyroclastic density currents particle abrasion occurs as particles interact with each other resulting in a reduction in grain size and production of fine grained ash particles. In addition, ash can be produced during secondary fragmentation of pumice fragments, due to the conservation of heat within the flow. These processes produce large quantities of very fine grained ash which is removed from pyroclastic density currents in co-ignimbrite ash plumes.

Physical and chemical characteristics of volcanic ash are primarily controlled by the style of volcanic eruption Volcanoes display a range of eruption styles which are controlled by magma chemistry, crystal content, temperature and dissolved gases of the erupting magma and can be classified using the Volcanic Explosivity Index (VEI). Effusive eruptions (VEI 1) of basaltic composition produce <105 m3 of ejecta, whereas extremely explosive eruptions (VEI 5+) of rhyolitic and dacitic composition can inject large quantities (>109 m3) of ejecta into the atmosphere. Another parameter controlling the amount of ash produced is the duration of the eruption: the longer the eruption is sustained, the more ash will be produced. For example, the second phase of the 2010 eruptions of Eyjafjallajokuli was classified as VEI 4 despite a modest 8 km high eruption cblUrnn, bllt the eruption cftntlhUed for 3 hlottth, which allowed a large volume of ash to be ejected into the atmosphere.

The types of minerals present in volcanic ash are dependent on the chemistry of the magma from which it was erupted. Considering that the most abundant elements found in magma are silica (Si02) and oxygen, the various types of magma (and therefore ash) produced during volcanic eruptions are most commonly explained in terms of their silica content. Low energy eruptions of basalt produce a

characteristically dark coloured ash containing -45 - 55% silica that is generally rich in iron (Fe) and magnesium (Mg). The most explosive rhyolite eruptions produce a felsic ash that is high in silica (>69%) while other types of ash with an intermediate composition (e.g., andesite or dacite) have a silica content between 55-69%.

The principal gases released during volcanic activity are water, carbon dioxide, sulphur dioxide, hydrogen, hydrogen sulphide, carbon monoxide and hydrogen chloride. These sulphur and halogen gases and metals are removed from the atmosphere by processes of chemical reaction, dry and wet deposition, and by adsorption onto the surface of volcanic ash.

It has long been recognised that a range of sulphate and halide (primarily chloride and fluoride) compounds are readily mobilised from fresh volcanic ash. It is considered most likely that these salts are formed as a consequence of rapid acid dissolution of ash particles within eruption plumes, which is thought to supply the captions involved in the deposition of sulphate and halide salts.

While some 55 ionic species have been reported in fresh ash leachates the most abundant species usually found are the captions Na+, K+, Ca2+ and Mg2+ and the anions CI-, F- and S042-. Molar ratios between ions present in leachates suggest that in many cases these elements are present as simple salts such as NaCI and CaS04. In a sequential leaching experiment on ash from the 1980 eruption of Mount St. Helens, chloride salts were found to be the most readily soluble, followed by sulphate salts Fluoride compounds are in general only sparingly soluble (e.g., CaF2, MgF2), with the exception of fluoride salts of alkali metals and compounds such as calcium hex fluorosilicate (CaSiF6). The pH of fresh ash leachates is highly variable, depending on the presence of an acidic gas condensate (primarily as a consequence of the gases S02, HCI and HF in the eruption plume) on the ash surface.

The crystalline-solid structure of the salts act more as an insulator than a conductor. However, once the salts are dissolved into a solution by a source of moisture (e.g., fog, mist, light rain, etc.), the ash may become corrosive and electrically conductive. A recent study has shown that the electrical conductivity of volcanic ash increases with increasing moisture content, increasing soluble salt content, and increasing compaction (bulk density). The ability of volcanic ash to conduct electric current has significant implications for electric power supply systems.

Particle of volcanic ash from Mount St. Helens.

Volcanic ash particles erupted during magmatic eruptions are made up of various fractions of vitric (glassy, non-crystalline), crystalline or lithic (non-magmatic) particles. Ash produced during low viscosity magmatic eruptions (e.g., Hawaiian and Strombolian basaltic eruptions) produce a range of different pyroclasts dependent on the eruptive process. For example, ash collected from Hawaiian lava fountains consists of sideromelane (light brown basaltic glass) pyroclasts which contain rare microliters (small quench crystals) and phenocrysts. Slightly more viscous eruptions of basalt (e.g., Strombolian) form a variety of pyro lasts from irregular sideromelane droplets to blocky tachylite (black to dark brown microcrystalline pyro lasts). In contrast, most high-silica ash (e.g. rhyolite) consists of pulverised products of pumice (vitric shards), individual phenocrysts (crystal fraction) and some lithic fragments (xenoliths).

Ash generated during phreatic eruption[e]ns primarily consists of hydrothermally altered lithic and mineral fragments, commonly in a clay matrix. Particle surfaces are often coated with aggregates of zeolite crystals or clay and only relict textures remain to identify pyroclastic types.

Morphology

Light microscope image of ash from the 1980 eruption of Mount St. Helens,

Washington.

The morphology (shape) of volcanic ash is controlled by a plethora of different eruption and kinematic processes. Eruptions of low-viscosity magmas (e.g., basalt) typically form droplet shaped particles. This droplet shape is, in part, controlled by surface tension, acceleration of the droplets after they leave the vent, and air friction. Shapes range from perfect spheres to a variety of twisted, elongate droplets with smooth, fluidal surfaces. The morphology of ash from eruptions of high-viscosity magmas (e.g. , rhyolite, dacite, and some andesite's) is mostly dependent on the shape of vesicles in the rising magma before disintegration. Vesicles are formed by the expansion of magmatic gas before the magma has solidified. Ash particles can have varying degrees of vascularity and vesicular particles can have extremely high surface area to volume ratios. Concavities, troughs, and tubes observed on grain surfaces are the result of broken vesicle walls. Vitric ash particles from high-viscosity magma eruptions are typically angular, vesicular pumice us fragments or thin vesicle-wall fragments while lithic fragments in volcanic ash are typically equate, or angular to sub rounded. Lithic morphology in ash is generally controlled by the mechanical properties of the wall rock broken up by spalling or explosive expansion of gases in the magma as it reaches the surface.

The morphology of ash particles from phreatomagmatic eruptions is controlled by stresses within the chilled magma which result in fragmentation of the glass to form small blocky or pyramidal glass ash particles. Vesicle shape and density play only a minor role in the determination of grain shape in phreatomagmatic eruptions. In this sort of eruption, the rising magma is quickly cooled on contact with ground or surface water. Stresses within the "quenched" magma cause fragmentation into five dominant pyroclast shape-types: blocky and equant; vesicular and irregular with smooth surfaces; moss-like and convoluted; spherical or drop-like; and plate-like.

The density of individual particles varies with different eruptions. The density of volcanic ash varties between 700-1200 kg/m3 for pumice, 2350-2450 kg/m3 for glass shards, 2700-3300 kg/m3 for crystals, and 2600-3200 kg/m3 for lithic particles. Since coarser and denser particles are deposited close to source, fine glass and pumice shards are relatively enriched in ash fall deposits at distal locations. The high density and hardness (~5 on the Mohs Hardness Scale) together with a high degree of angularity, make some types of volcanic ash (particularly those with a high silica content) very abrasive.

Grain size

Volcanic ash grain size distributions. Volcanic ash consists of particles (pyroclasts) with diameters <2 mm (particles >2 mm are classified as lapilli) and can be as fine as 1 pm The overall grain size distribution of ash can vary greatly with different magma compositions. Few attempts have been made to correlate the grain size characteristics of a deposit with those of the event which produced it, though some predictions can be made. Rhyolite magmas generally produce finer grained material compared to basaltic magmas, due to the higher viscosity and therefore exclusivity. The proportions of fine ash are higher for silicic explosive eruptions, probably because vesicle size in the preemptive magma is smaller than those in mafic magmas. There is good evidence that pyroclastic flows produce high proportions of fine ash by commination and it is likely that this process also occurs inside volcanic conduits and would be most efficient when the magma fragmentation surface is well below the summit

A further invention is a set for cleaning surfaces, comprises a nozzle embedded on a lance connected with a hose with the dry ice dispensing device, a compressor producing compressed air and a dispenser (adapter) containing the abrasive material. The set characterises in that next to the dispensing device of dry ice there is mounted a dispenser for the abrasive material It is connected with a connecting ctesvice to the dispensing device. It is very advantageous to put the compressor in a thermally insulated container. Mounting the insulated container comprising the compressor on a vehicle makes the set easy to remove to places needed to be cleaned, such as switch-rooms, transformer stations, production lines, buildings, parking places, public places.

The Feeder with dry ice is connected by a special hose. The feeder is the attached adapter (dispenser fig.1 nr.4) for abrasives materials which are connected to a separate hose. Dry ice gets mixed with abrasive material in the tip and forms a common stream of cleaning. Another way of mixing dry ice with the abrasives material snap-feeding a material into the machine with a dry ice just prior to delivery of the container of dry ice. Here the dry ice is mixed with the material just before entering into the hose.

A further effect of the present method is that while cleaning gas and oil pipes with the present method is that after the cleaning the surfaces of the pipes on the surface the pipes due to the micro rawness achieved by the cleaning method using volcanic ash powder. The adhetives can flow in the micro pores created by the abrasive effect of the volcanic ash powder. A later protective coating attached to the pipe surface will easily sticked on the surface from the pipe. The protective coating is a plastic film containing an adhetive side with witch is attached to the pipe surface.

The invention is laid out in the claims:

1. A method of cleaning surfaces, especially surfaces hard surfaces covered with removable materials of all kinds, in which, using a dry ice method with addition of abrasive.

2. A method of claim 1 , where in the abrasive is volcanic ash powder fused alumina, mixed corundum, glass beads, or glass grit or combination thereof. 3. A method of claim 1 , where in the is volcanic ash powder is from natural sollrce.

4. Method of claim 1 -2 wherein the granulation of the abrasive material is dispensed by the device to dry ice or dropped directly into the dry ice.

5. A method of claim 1-4, wherein a stream of compressed air is applied onto a to be cleaned surface at a safe distance,

6. A method of claim 4 wherein characterized that compressed air is passed through a container with dry ice of the temperature from -70[deg.]C to -30[deg.]C .and granulation from 1 ,5 to 5 mm.

7. A method of claim 4 wherein characterized that the granulation of the dry ice is 0.01 to 20 mm.

8. A method of claim 7 wherein characterized that the granulation of the dry ice is 1.5 to 5 mm.

9. A method of claim 8 wherein characterized that the granulation size of the Vulcan ash powder is 0,01 to 5 mm, preferably from 0,01 to 2mm, most preferably from 0,02 to 0,5mm 0. A set for cleaning surfaces using the cleaning method of one of claims 1 to 9

1 1 . A set of cleaning surfaces surface, comprising a nozzle embedded on a lance connected by a house with a dispensing device of a dry ice and compressed air supplied by a compressor, characterized in that between the nozzle (7) and the dispensing device (6) of dry ice there is a dispenser for abrasive material (4) where the abrasion material is dispensed by the device to dry ice or sprinkle directly to the dry ice.

12. The set for cleaning surfaces according to claim 6, characterized in that the compressor (2) is embedded in a thermally insulated container (1 ).

13. The set for cleaning surfaces according to claims 6-8, characterized in that the set is mounted on a vehicle.

14. Method for achieving micro rawness to a surface characterized by the micro rawness is achieved by using the method of claim 1 .

15. Method of claim 14 whereby the surface is the surface of a gas or oil pipe.

16. Method of claim 15 whereby to the surface of the pipe is attached a protective coating film witch has an adhesive side with witch it is attached to the pipe surface after the step of the micro rawness.

17. Method of claim 16 whereby the film is a plastic film. Description of the figure 1 :

In a method of cleaning surfaces, especially hard surfaces covered with removable materials of all kinds, are removed by dry ice with the addition of abrasive and restoring such as (volcanic powder, brown fused alumina, fused alumina white, mixed corundum, glass beads, glass grit). Method: a stream of compressed air is applied to the surface being cleaned in a safe distance. Before use, compressed air (1) is passed through a container of dry ice and a dispensing device (4) with abrasive material at a temperature of from -70 ° C to -30 ° C, and granulation of 1.5 to 5 mm. Kit for cleaning surfaces comprises a nozzle mounted on the lance (7) connected to a dry ice dispensing device with wiping materials (5) using special hoses, and air supplied by the compressor (1). Abrasion material is dispensed by the device to dry ice or sprinkle directly to the dry ice (4).

Claims

Claims:

1. A method of cleaning surfaces, especially surfaces hard surfaces covered with removable materials of all kinds, in which, using a dry ice method with addition of abrasive.

2. A method of claim 1 , where in the abrasive is volcanic ash powder fused alumina, mixed corundum, glass beads, or glass grit or combination thereof.

3. A method of claim 1 , where in the is volcanic ash powder is from natural source.

4. Method of claim 1 -2 wherein the granulation of the abrasive material is dispensed by the device to dry ice or dropped directly into the dry ice.

5. A method of claim 1-4, wherein a stream of compressed air is applied onto a to be cleaned surface at a safe distance,

6. A method of claim 4 wherein characterized that compressed air is passed through a container with dry ice of the temperature from -70[deg.]C to -30[deg.]C .and granulation from 1 ,5 to 5 mm.

7. A method of claim 4 wherein characterized that the granulation of the dry ice is 0.01 to 20 mm.

8. A method of claim 7 wherein characterized that the granulation of the dry ice is 1.5 to 5 mm.

9. A method of claim 8 wherein characterized that the granulation size of the Vulcan ash powder is 0,01 to 5 mm, preferably from 0,01 to 2mm, most preferably from 0,02 to 0,5mm

10. A set for cleaning surfaces using the cleaning method of one of claims 1 to 9 . A set of cleaning surfaces surface, comprising a nozzle embedded on a lance connected by a house with a dispensing device of a dry ice and compressed air supplied by a compressor, characterized in that between the nozzle (7) and the dispensing device (6) of dry ice there is a dispenser for abrasive material (4) where the abrasion material is dispensed by the device to dry ice or sprinkle directly to the dry ice.

12. The set for cleaning surfaces according to claim 6, characterized in that the compressor (2) is embedded in a thermally insulated container (1 ).

13. The set for cleaning surfaces according to claims 6-8, characterized in that the set is mounted on a vehicle.

14. Method for achieving micro rawness to a surface characterized by the micro rawness is achieved by using the method of claim .

15. Method of claim 14 whereby the surface is the surface of a gas or oil pipe.

15. Method of claim 14 whereby the surface is the surface of a gas or oil pipe.

16. Method of claim 15 whereby to the surface of the pipe is attached a protective coating film witch has an adhesive side with witch it is attached to the pipe surface after the step of the micro rawness.

17. Method of claim 16 whereby the film is a plastic film.