Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B08—CLEANING
  • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
  • B08B7/00—Cleaning by methods not provided for in a single other subclass or a single group in this subclass
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B08—CLEANING
  • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
  • B08B17/00—Methods preventing fouling
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B08—CLEANING
  • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
  • B08B3/00—Cleaning by methods involving the use or presence of liquid or steam
  • B08B3/04—Cleaning involving contact with liquid
  • B08B3/08—Cleaning involving contact with liquid the liquid having chemical or dissolving effect
• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01H—STREET CLEANING; CLEANING OF PERMANENT WAYS; CLEANING BEACHES; DISPERSING OR PREVENTING FOG IN GENERAL CLEANING STREET OR RAILWAY FURNITURE OR TUNNEL WALLS
  • E01H1/00—Removing undesirable matter from roads or like surfaces, with or without moistening of the surface
  • E01H1/001—Treatment of dispersed oil or similar pollution on roads, for instance devices for applying treating agents
• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01H—STREET CLEANING; CLEANING OF PERMANENT WAYS; CLEANING BEACHES; DISPERSING OR PREVENTING FOG IN GENERAL CLEANING STREET OR RAILWAY FURNITURE OR TUNNEL WALLS
  • E01H1/00—Removing undesirable matter from roads or like surfaces, with or without moistening of the surface
  • E01H1/10—Hydraulically loosening or dislodging undesirable matter; Raking or scraping apparatus ; Removing liquids or semi-liquids e.g., absorbing water, sliding-off mud
  • E01H1/101—Hydraulic loosening or dislodging, combined or not with mechanical loosening or dislodging, e.g. road washing machines with brushes or wipers
  • E01H1/103—Hydraulic loosening or dislodging, combined or not with mechanical loosening or dislodging, e.g. road washing machines with brushes or wipers in which the soiled loosening or washing liquid is removed, e.g. by suction

Definitions

• the present invention relates to a method for cleaning porous surfaces, in particular surface coatings such as "draining mixes”.
• the surface coatings known as “draining coated materials” which are used more particularly as coatings for roads or other road surfaces, have as their object the rapid evacuation of rainwater in order to keep its characteristics on the surface, in particular as regards concerns the grip of vehicles, because they avoid the risk of slipping and standing water surfaces.
• layers 4 to 5 cm thick are used composed of bitumen coating gravel with typically 0/10 or 0/14 for grain size.
• These porous, non-waterproof layers are placed on a waterproof substrate, generally made of concrete. Similar porous coatings have been used for tennis courts, for example.
• Draining asphalts have, when they are placed, empty cavities, communicating with each other, preferably representing 10 to 20% of their total volume, which allow the flow of water.
• this type of coating has the disadvantage that the cavities fill more or less quickly with various waste, leading to an increasingly significant reduction in the initial porosity.
• the filling of the cavities is mainly carried out by earth and sand up to 95% and by various compounds, mainly petroleum residues, rubber powder, metals, carbon, organic matter, ... often around 5%. These 5% of various compounds agglomerate the sands by transforming them into a compact and waterproof block.
• an impermeable surface layer is formed on the surface of the draining asphalt. If the total volume of the cavities exceeds 30%, there is a risk of foul pollution by accumulation of standing water laden with organic matter. It is therefore not possible to significantly increase the size of the cavities in order to delay their clogging.
• a cross section of a draining asphalt often leads to the observation of two layers of pollution: predominantly organic pollution is observed on the surface while petroleum products agglomerating sands and gravels are dominant in depth.
• the machine used in the context of patent EP-0617174 equipped with a device for projecting a pressurized fluid, characterized by a member rotating around a vertical axis and provided with nozzles for projecting fluid, does is not suitable for cleaning draining asphalt because experience shows that the application of a simple high pressure water jet on the upper surface of the draining asphalt does not unclog the fine particles housed in the cavities in order to be able to suck them up.
• a simple provisional improvement is thus obtained due to the packing effect of the materials and waste filling the cavities without providing a real solution to the problem of cleaning and restoring the initial porosity of the coating.
• the agglomerating products remain around the sands and gravels which do not recover their mobility and which cannot be extracted during aspiration. Due to the packing of the materials and waste which are not extracted by this type of cleaning, a subsequent cleaning is then all the more difficult.
• the aspirations brought into play which are very powerful can produce detachments from the draining asphalt layer, which accelerates the destruction of the draining asphalt surface without solving the problem posed.
• the subject of the present invention is a method of cleaning porous surfaces, such as drainage mixes used as road surfaces or other public or private roads, which makes it possible to avoid the drawbacks of the known methods and to restore the initial porosity without damaging the surface and without the packing effect of clogging materials and waste, and which allows the waste to be extracted while respecting environmental protection requirements.
• Patent application DE-4014854 A1 discloses a cleaning process using an enzymatic washing liquid for removing grease from concrete, cement or stone surfaces.
• the liquid is spread over the surface to be cleaned by brushing and the simultaneous application of pressurized air arriving through the brushes. It is necessary to work at a higher temperature than room temperature and repeat the washing and brushing process several times before rinsing the surface with water.
• the method proposed by the invention which relates to deep cleaning and not to the surface, uses neither an application with pressurized air, nor brushing the surface to be cleaned.
• the washing liquid must penetrate into the cavities of the draining mix where it can exert its unclogging action.
• the present invention provides that the rinsing water is applied under pressure by nozzles having a slight inclination on the horizontal before being sucked together with the unclogged residues.
• the patent FR 2640528 proposes the use of microorganisms for the direct degradation of coloring matters and the patent WO 9603754A1 that of microorganisms for decontaminating metals and cements in nuclear installations. These methods certainly use microorganisms but have no relation to the unclogging of particles in the draining mixes.
• the actual washing can be preceded by a pretreatment of the surface area of the porous surface, the purpose of which is to dissolve the hydrocarbon particles which will then be biodegraded during the washing consisting of a bacterial treatment.
• the prewash liquid is obtained by dilution in water, at a rate of 0.2 to 1% for example, of a biosurfactant complex derived from bacteria, associated with a biodegradable surfactant.
• the washing operation is followed by a rinsing / aspiration operation after sufficient time for the washing liquid to act on the deep area.
• a rinsing liquid is spread and then collected by suction together with the unclogged residues.
• the rinsing liquid is preferably pressurized water, of the order of 200 to 350 bars from the feed pumps, distributed inside a rinsing bell, by a rotary arm carrying ejection nozzles which have a small angle, of the order of 30 ° relative to the surface to be cleaned, and which are arranged at a distance advantageously between 40 and 60 mm from the surface to be cleaned.
• the flow rinse aid is preferably about 1.5 liters per minute and per square decimetre of surface area of the bell.
• the rinsing bell, enclosing the nozzle carrying arm is kept at a fixed distance from the ground, and is sealed by a flexible seal, for example made of rubber, rubbing lightly on the porous surface to be cleaned.
• the process according to the invention allows the destruction of the surface layer which could have formed on the surface of the porous coating of surfaces, then of the deep layer of the products agglomerating the sands which are in the cavities of the porous coatings of surfaces.
• the sands blocking the cavities regain their mobility and can then be extracted from the coating by suction.
• the invention proposes the use of a washing liquid containing enzymes and bacteria which, essentially, destroy the agglomerating products.
• the washing liquid is composed of water in which the enzymatic and bacterial solutions are diluted without the addition of solvents. These solutions are preferably produced in situ.
• the bacteria used in the context of the invention are advantageously of the pseudomonas, moraxella, bacillus type , alone or in consortium (associated) with other bacteria which have a strong appetite for hydrocarbons.
• the exact type of bacteria or mixture of bacteria may vary and will be determined according to the type of sealants, in particular the predominant type of organic waste and hydrocarbons identified on the site to be treated.
• enzymes take off the nutrients that bacteria need thanks to their “bio-surfactant” or “natural surfactant” power, which brings food within reach of bacteria.
• Petroleum products are transferred by the formation of macro- and micro-emulsions which increase the solubility of the binder.
• Enzymes hydrolyze chemical chains in hydrocarbons to allow bacteria to digest hydrocarbon compounds with shorter chains. Bacteria renew themselves in about twenty minutes and produce new enzymes. At the end of the cycle, the bacteria reject carbon dioxide, water, non-digestible matter.
• Enzymes and bacteria which remain in the draining asphalt after cleaning according to the invention remain as long as the bacteria are able to feed on new projections of organic matter and a minimum humidity is maintained. They prevent the accumulation of products agglomerating sands and gravels.
• the bacteria selected for the washing liquid are harmless to the environment and die when they no longer have enough food.
• the organic and hydrocarbon waste that falls on the road during its frequentation and the cycle of the seasons contributes to a regular supply of food.
• the enzymes and bacteria used are not only biodegradable but biodegradable.
• the invention has the advantage of allowing the extraction of particularly clean sands, which can be landfilled without bringing pollution.
• the liquids recovered after being used for entraining agglomerating products are loaded with petroleum residues, various organic residues, dust, sand and gravel, carbon powder, and a low concentration of enzymes and bacteria which are treated, if necessary, to reach standardized concentrations, less than 1 ppm or 10 ppm depending on the enzymes and bacteria used, before discharge into existing sanitation networks. No pollution is to be feared because of these discharges because they are cleaned by bacteria as in a wastewater treatment plant.
• the method according to the invention is implemented by means of a cleaning machine with powerful mechanical-hydraulic means.
• the prewash liquid of the surface area of the porous surface is advantageously obtained by dilution in water, for example, at a rate of 0.2 to 1% of a complex of biosurfactant enzymes, derived from microorganisms, playing the role of neutral detergents and surfactants compatible with the bacterial cultures found on site.
• the basic preparation usefully has the following characteristics: apparent density 1 pH between 10 and 12 pH in 1% solution between 8.5 and 11.5 viscosity ⁇ 400 cts fully soluble in water
• the rinsing liquid is preferably pressurized water, of the order of 200 to 350 bars from the feed pumps, distributed inside the rinsing bells, by a rotary arm carrying nozzles ejection.
• the flow rate of the rinsing liquid is preferably 1.5 liters per minute and per square decimetre of surface area of the bell.
• These nozzles have a small angle, of the order of 30 ° relative to the surface to be cleaned, whence jets which are almost tangent to the surface to be cleaned, which makes it possible to avoid any risk of compaction.
• the rinsing bell enclosing the nozzle support arm is kept at a fixed distance from the porous surface to be cleaned.
• the distance between the ground and the ejection nozzles is preferably between 40 and 60 mm.
• the rotation of the arm carrying the nozzles creates a hydraulic cyclone which generates a natural depression large enough to suck, by its only force, the rinsing liquid which is loaded with waste and sand.
• the quantity of sands to be sucked up can become very large, for example in the case of roads leaving a site. More than 10 kg of sand per m 2 of rolling surface could be found in certain areas of the Paris ring road. It is then advisable to carry out a powerful suction of the washing water loaded with sand.
• an additional suction by ramp can be envisaged to improve the extraction of the rinsing liquid and the sands still trapped in the draining mix. It is also possible to provide an annular suction complementary to the suction by the internal cyclone with the cleaning bell and several parallel or successive bells. It is noted that too powerful suction of the sands, in the presence of too little water, can lead to their accumulation in the upper layer of the draining asphalt. There is then formation of a compact layer which fills the surface cavities of the draining asphalt and which makes it waterproof.
• a cleaning test of an urban site using the process according to the invention was carried out.
• a draining mix with an average porosity of 1.26 was installed in July 1991. No cleaning of the porous coating to restore its original characteristics was carried out for 38 months. The porosity measured is then zero.
• a cleaning with prewash, washing, rinsing and suction, according to the invention is then carried out.
• an average porosity of the order of 0.6 could be observed.
• Rinsing leaves bacteria on the site.
• Five days after the cleaning carried out according to the invention a thunderstorm occurs.
• a new measurement of porosity gives an average of 1 with peaks at 1.18, that is to say a porosity practically returned to its original value, and shows that the bacteria left on the site during rinsing have continued to feed on the clogs.

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• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Environmental & Geological Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Detergent Compositions (AREA)
• Purification Treatments By Anaerobic Or Anaerobic And Aerobic Bacteria Or Animals (AREA)
• Cleaning Implements For Floors, Carpets, Furniture, Walls, And The Like (AREA)

Applications Claiming Priority (2)

Publications (2)

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ID=9492259

Family Applications (1)

Country Status (6)

Cited By (5)

Families Citing this family (1)

Citations (4)

• 1996
  • 1996-05-20 FR FR9606203A patent/FR2748676B1/fr not_active Expired - Fee Related
• 1997
  • 1997-05-16 ES ES97401094T patent/ES2186852T3/es not_active Expired - Lifetime
  • 1997-05-16 EP EP97401094A patent/EP0808671B1/de not_active Expired - Lifetime
  • 1997-05-16 DK DK97401094T patent/DK0808671T3/da active
  • 1997-05-16 DE DE69717909T patent/DE69717909T2/de not_active Expired - Lifetime
  • 1997-05-16 AT AT97401094T patent/ATE229846T1/de not_active IP Right Cessation

Patent Citations (4)

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