EP1942241B1 - Installation for getting rid of dust emissions from building demolition operations - Google Patents

Abstract

The installation (1) has a set of masts (11-14) susceptible to vertically rise under the effect of compressed air pressure. The masts are connected to each other by a set of cables, and mist diffusing nozzles are supported by cables. A set of panels closes a passage of dust. Each nozzle includes a spherical or cylindrical cavity in which a compressed air circuit and a water circuit are opened. An independent claim is also included for a method for suppressing emissions of dust during demolition operations of building.

Description

The invention relates to an installation for protecting the environment of a building or structure to be demolished.

The invention relates to an installation of this type suitable for demolition by mechanical means or explosives.

The invention also relates to a method for implementing the installation according to the invention.

The demolition of buildings or structures results in the emission of dust in the immediate environment or near the demolition site.

Depending on the techniques used and depending on the structure or composition of the materials forming the building or structure subject to demolition, these emissions will be more or less important and cause more or less nuisance.

Thus, if the duration of the demolition operations decreases with the power of the mechanical or explosive means used, the noise and dust emissions, meanwhile, increase with this power.

In particular, in case of demolition by a plurality of explosive charges, the dust emissions are concentrated over a particularly short period of time, which causes a dust concentration difficult to accept by the local residents.

The immediate environment of the buildings or works concerned can be so close or sensitive (case of dense urbanization) that the demolition operations by mechanized means of high power or by explosive charges prove very difficult to achieve, or even prohibited by the regulation.

Finally, the weather conditions, and in particular the presence of a strong wind during the demolition operations, can make these operations even more delicate.

It therefore appears that the implementation of devices to limit or eliminate dust emissions during demolition operations are likely to reduce environmental impacts, and improve the economic conditions for carrying out such operations.

We have already proposed very diverse solutions, which reduce environmental impacts, but which do not provide satisfactory answers.

Indeed, some proposals are unrealistic, such as that of building a rigid structure and waterproof half-warhead above the building and create a depression inside this structure. For example, the document JP2003147976 who proposes to build a building around the work to be demolished, or the document JP2003328596 which describes a dome.

A variant of this solution is described in the document JP2004290933 in which the solution is to surround the building or structure concerned by means of a vertically rising hollow membrane, the lower part of which is filled with ballast water and whose upper part is filled with air under pressure.

There are also solutions to cool the building before demolition, through the use of very large quantities of gas (nitrogen for example). For example, see the document JP 2004162493 .

Another solution consists in watering the buildings before the demolition. Watering is done mainly with water but specific binders or additives can be added to improve the solution. For example, reference is made to the document GB 2 396 381 which describes such a solution. Indeed, it is proposed the use of foam to wet or even fill the building before demolition.

As we have already mentioned, all the existing solutions are not totally satisfactory.

Solutions implementing a structure are for example relatively difficult to implement. Moreover, they do not seem compatible with explosive demolition: in all cases, with closed structures, it is undeniable that the simple blast generated by the explosion will cause the destruction of the proposed facilities. Thus, such structures will most often be for single use, except to build them at a distance from buildings as they would be economically unfeasible.

In addition, experience shows that the solutions of humidifying buildings and structures are inefficient. Indeed, these solutions require quantities of water that generate a significant pollution of the site. The use of foams or binders exacerbates environmental impacts during and after demolition operations.

Existing solutions must therefore be improved to overcome these defects.

The solution proposed by the invention aims in particular to solve all or part of the limitations and deficiencies of the procedures described above.

To achieve this objective, the invention provides an installation for suppressing dust emissions during the demolition operations of a building or structure, characterized in that it comprises a plurality of masts capable of to stand up vertically under the effect of a pressure of compressed air, the masts being interconnected by a plurality of cables, at least some of which are provided with means for sprinkling a building or a work.

• elle comprend des moyens pour obstruer le passage de poussières ;
• les moyens d'obstruction comprennent des panneaux articulés pouvant tourner librement autour d'un axe s'étendant sensiblement parallèlement aux câbles ;
• les panneaux articulés ont une hauteur supérieure à l'entraxe séparant deux câbles successifs, lorsque les mâts sont déployés sous l'effet de la pression d'air comprimé ;
• les moyens d'aspersion comprennent des buses comportant chacune au moins une cavité dans laquelle débouchent à la fois un circuit d'air comprimé et un circuit d'eau sous pression ;
• le circuit d'air comprimé est relié d'une part à chacun des mâts gonflables et d'autre part à chacune des buses d'aspersion ;
• le circuit d'air comprimé alimentant la cavité de chacune des buses est relié au volume intérieur d'au moins l'un des mâts gonflables par une canalisation comportant au moins un dispositif d'ouverture/fermeture commandé en fonction du volume intérieur d'au moins un mât gonflable.

The installation according to the invention may furthermore have at least one of the following characteristics:

• it comprises means for obstructing the passage of dust;
• the obstruction means comprise hinged panels which can rotate freely about an axis extending substantially parallel to the cables;
• the articulated panels have a height greater than the distance between two successive cables, when the masts are deployed under the effect of the pressure of compressed air;
• the spraying means comprise nozzles each having at least one cavity into which both a compressed air circuit and a pressurized water circuit open;
• the compressed air circuit is connected on the one hand to each of the inflatable masts and on the other hand to each of the spray nozzles;
• the compressed air circuit supplying the cavity of each of the nozzles is connected to the internal volume of at least one of the inflatable masts by a duct comprising at least one controlled opening / closing device as a function of the internal volume of at least one of less an inflatable mast.

This object is also achieved by a method for suppressing dust emissions during the demolition operations of a building or structure, characterized in that a plurality of masts of an installation according to the invention is raised vertically, under the effect of pressure of compressed air, and the building or structure is sprayed with a mist formed from a plurality of nozzles arranged on cables stretched between the masts.

• on alimente la pluralité de buses génératrices du brouillard, par un débit d'air supérieur à celui fourni par les moyens de compression, le débit additionnel provenant du dégonflage d'au moins un mât.

The method according to the invention may furthermore have at least one of the following characteristics:

• the plurality of mist-generating nozzles is fed with an air flow rate greater than that supplied by the compression means, the additional flow rate resulting from the deflation of at least one mast.

• la figure 1 représente une vue schématique d'une installation selon l'invention mise en place à l'état de repos autour d'un bâtiment destiné à la démolition ;
• la figure 2 représente une vue schématique de l'installation de la figure 1, en état de fonctionnement ;
• les figures 3a, 3b représentent des vues schématiques d'une installation selon l'invention, en vue de face et en vue de côté respectivement.

Other features, objects and advantages of the present invention will appear on reading the detailed description which follows, and with reference to the appended drawings, given by way of non-limiting examples and in which:

• the figure 1 is a schematic view of an installation according to the invention set up in the state of rest around a building intended for demolition;
• the figure 2 represents a schematic view of the installation of the figure 1 , in operating condition ;
• the Figures 3a, 3b represent schematic views of an installation according to the invention, in front view and in side view respectively.

The installation comprises inflatable structures composed of a plurality of masts 11, 12, 13, 14 each having a height of approximately H ₁ = 1 m in the idle state ( figure 1 ), that is to say when they are deflated (atmospheric pressure), and deployed at a height of several tens of meters in working condition ( figure 2 ), for example at H ₂ = 30m under the action of inflation means or compressions 2.

These compression means 2 are for example formed by at least one compressor supplying compressed air at several bars, for example 7 bars, in each of the masts 11, 12, 13, 14.

It will be understood that the installation can include as many masts as necessary to surround the building 10.

Each mast is an inflatable structure having the general shape of a bellows via N inflatable pockets connected together, these pockets being for example referenced 11 ₁ , ..., 11 _i , ..., 11 _N for the mast 11.

These masts 11, 12, 13, 14 are equipped with means of fasteners 131, 132, 133 between the poles, for example hooks, between which cables 20 ₁ , ..., 20 _i , .. ., 20 _N stretched.

These cables 20 ₁ , ..., 20 _i , ..., 20 _{N also} support panels 21 ₁ , ..., 21 _i , ..., 21 _N-1 . These panels 21 ₁ , ..., 21 _i , ..., 21 _N-1 are preferably light, and articulated relative to the masts, at joints 210 ₁ , ..., 210 _i , ... , 210 _N-1 . These joints allow the panels to rotate freely about an axis extending substantially parallel to the cables.

These articulated panels have a height H greater than the center distance E ( figure 3b separating two successive cables, when the masts are deployed under the effect of compressed air, and so that they overlap partially.

Articulated panels are particularly useful during an explosion demolition. Indeed, the deployment of the masts, usually a few moments before the demolition of the building 10 by explosion, blocks the spread of dust without opposing significant resistance to the propagation of the shock wave.

For this purpose articulated panels 21 ₁ , ..., 21 _i , ..., 21 _N-1 are likely to take an open position (possibly close to the horizontal) at the precise moment of the passage of the shock wave following the explosion of the building or structure concerned. With these articulated panels 21 ₁ , ..., 21 _i , ..., 21 _N-1 , it is possible to obstruct the passage of dust, the latter arriving on the installation after the passage of the wave of choc.

The installation also comprises, according to one of its main features, nozzles 31, 32 of fog diffusion (water for example). These nozzles are supported by the cables or at least some of these cables 20 ₁ , ..., 20 _i , ..., 20 _N along which they are installed, preferably at regular intervals to form a regular mesh.

Each nozzle 31, 32 comprises a cavity (not shown), preferably spherical or cylindrical, into which both a compressed air circuit and a water circuit open at a pressure of a few bars (network pressure). The connections with the water circuit are not represented but it is represented on the figure 2 the jets of water 310, 320 corresponding from the cavity. The resulting jet is directed to the building 10 to demolish.

Ultrasonic vibrations generated by the arrival of air under pressure in the cavity have the effect of atomizing the water present in the same cavity; in a known manner, this atomization phenomenon causes the bursting of the water up to the molecular size. The common arrival of water and an air pressure thus makes it possible to form the mist, which is ejected from the nozzle, for example in the form of a cone whose apex coincides with the outlet orifice of the base and whose base is directed towards the building.

The molecules of water being naturally dipolar, they will be fixed to the particles of dust, themselves polarized; the weight of the many groups (water molecules + dust grains) being substantially greater than that of the dust particles alone, there is a phenomenon of very fast and very efficient plating of dust on the ground.

By rapid and effective, it should be understood that the installation 1 allows a plating of dust on the ground in a proportion of about 2 tons of dust per liter of atomized water and this in a few tens of seconds.

The pressurization of the inflatable masts 11, 12, 13, 14 has the effect of tensioning the cables and shrouds 41, 42, 43, 44 planted in the ground during assembly, thus creating a wall structure protecting the building 10.

In the absence of wind or blast, the protective walls formed by the installation will be almost closed, given the vertical position of the panels 21 ₁ , ..., 21 _i , ..., 21 _N-1 supported by cables.

The panels 21 ₁ , ..., 21 _i , ..., 21 _N-1 may be rigid shells or simple films of plastic or recycled material thick and relatively rigid.

It is understood, as mentioned above, that at the time of the explosion or in the event of a gust of wind, the panels take a position inclined relative to the vertical, which is cleaning a plurality of interstices between these panels and allows to preserve the installation 1 which is thus reusable.

The implementation of the installation 1 and its operation can be briefly summarized here.

First, the installation around the building or structure 10 to be demolished. Depending on the prevailing winds and more generally the weather conditions, it is possible to implement the installation on a part or around the building 10. The inflation of the masts is carried out some time before the demolition operation begins.

Once the installation 1 inflated, it will be noted that the commissioning of the sprinkler nozzles of the water mist, by the action of valves (not shown) towards the building. This action can begin before demolition begins and continues during and after this demolition. Especially in the case where the demolition is made by explosive, the diffusion of the fog will preferably be done before, during and after the explosion.

Once the operation is completed, the compressor (s) is cut off and the installation quickly collapses to resume its rest position.

In an advantageous variant of the implementation, the compressed air introduced into the nozzles originates wholly or partly from the reserve constituted by the inflated poles, and this air is added (additional flow) if necessary to the flow rate. air supplied by compression means 2, in turn electrically powered.

Thus, in the case where the compressor 2 operates simultaneously with the supply of air coming directly from at least one mast, the installation collapses slowly, the nozzles continuing to diffuse a dust fog during the collapse of the installation 1.

Still according to this variant, the installation provides that the compressed air circuit supplying the cavity of each of the nozzles is connected to the internal volume of at least one inflatable mast by a pipe comprising at least one opening / closing device (no represent). This opening / closing device is thus controlled as a function of the internal volume of at least one inflatable mast.

The invention described above thus has many advantages over existing art.

It proposes a modular structure or installation 1, transportable in small volumes compatible with road transport templates, easy to implement and not requiring the use of handling means or work at height.

In addition, the modular structure 1 according to the invention can be adapted to the building treatment of shapes and dimensions very varied.

It also has the advantage of being placed in the immediate vicinity of buildings to be demolished, to be able to suffer the consequences of an explosion / explosion at these buildings without being damaged or even displaced and therefore to be reusable for several demolition operations in different sites.

An additional advantage of the invention is to allow the total or almost total overpressure of any dust dispersion beyond a strictly limited perimeter.

Claims (9)

1. An installation (1) for suppressing emissions of dusts during operations for demolishing a building or a structure, characterized in that it includes a plurality of masts (11, 12, 13, 14) capable of being erected vertically under the effect of compressed air pressure, the masts (11, 12, 13, 14) being connected to each other through a plurality of cables (20₁,..., 20_i,..., 20_N), at least certain of which are provided with means (31, 32) for spraying a building or a structure..
2. The installation according to the preceding claim, characterized in that it comprises means (21₁,..., 21_i,..., 21_N-1), for blocking up the passage for dusts.
3. The installation according to the preceding claim, characterized in that the blocking means (21₁,..., 21_i,..., 21_N-1) comprise jointed panels which may rotate freely around an axis extending substantially parallel to the cables.
4. The installation according to the preceding claim, characterized in that the jointed panels (21₁,..., 21_i,..., 21_N-1) have a height (H) greater than the centre distance (E) separating two successive cables, when the masts are deployed under the effect of the compressed air pressure.
5. The installation according to any of the preceding claims, characterized in that the spraying means (31, 32) comprise nozzles each including at least one cavity into which open both a compressed air circuit and a pressurized water circuit.
6. The installation according to the preceding claim, characterized in that the compressed air circuit is connected to each of the inflatable masts (11, 12, 13, 14) on the one hand and to each of the spray nozzles on the other hand.
7. The installation according to any of claims 5 or 6, characterized in that the compressed air circuit feeding the cavity of each of the nozzles is connected to the inner space of at least one of the inflatable masts through a duct including at least one opening/closing device controlled according to the inner space of at least one inflatable mast.
8. A method for suppressing emissions of dusts during operations for demolishing a building or a structure, characterized in that a plurality of masts (11, 12, 13, 14) of an installation (1) according to any of the preceding claims is erected vertically, under the effect of compressed air pressure, and the building or the structure is sprayed with mist formed from a plurality of nozzles positioned on tensioned cables between the masts.
9. The method according to the preceding claim, characterized in that the plurality of mist-generating nozzles is fed with an airflow rate greater than that provided by the compression means, the additional flow rate stemming from the deflation of at least one mast.

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