Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N1/00—Sampling; Preparing specimens for investigation
  • G01N1/02—Devices for withdrawing samples
  • G01N1/22—Devices for withdrawing samples in the gaseous state
  • G01N1/2202—Devices for withdrawing samples in the gaseous state involving separation of sample components during sampling
  • G01N1/2205—Devices for withdrawing samples in the gaseous state involving separation of sample components during sampling with filters
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N1/00—Sampling; Preparing specimens for investigation
  • G01N1/02—Devices for withdrawing samples
  • G01N1/22—Devices for withdrawing samples in the gaseous state
  • G01N1/2226—Sampling from a closed space, e.g. food package, head space
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
  • G01N15/06—Investigating concentration of particle suspensions
  • G01N15/0606—Investigating concentration of particle suspensions by collecting particles on a support
  • G01N15/0618—Investigating concentration of particle suspensions by collecting particles on a support of the filter type
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N1/00—Sampling; Preparing specimens for investigation
  • G01N1/02—Devices for withdrawing samples
  • G01N1/22—Devices for withdrawing samples in the gaseous state
  • G01N1/2226—Sampling from a closed space, e.g. food package, head space
  • G01N2001/2241—Sampling from a closed space, e.g. food package, head space purpose-built sampling enclosure for emissions
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N1/00—Sampling; Preparing specimens for investigation
  • G01N1/02—Devices for withdrawing samples
  • G01N1/22—Devices for withdrawing samples in the gaseous state
  • G01N2001/2285—Details of probe structures
  • G01N2001/2288—Filter arrangements

Definitions

• Dust collecting system method of determining at least one property of a material in terms of clearance
• the invention relates to a dust collection system, a method for determining at least one property of a material for dust generation, and a method of watering a soil.
• the objective of the invention is to minimize the amount of water consumed by the watering operations indicated above.
• the object of the invention is to make it possible to better take into account the quantities of dust released by a material, in particular a material constituting a soil. Knowledge of quantities (and / or of the composition, or other properties) of dust released by the material can then be exploited for different purposes:
• a dust collection system for determining the amounts of dust released by the material, especially under the effect of wind.
• this dust collection system comprises an enclosure adapted to receive a test piece of a material to be evaluated, such that the material has a free surface disposed inside the enclosure;
• an air circulator configured to circulate air along said surface in the enclosure
• a dust collector configured to collect downstream of the specimen dust raised by said air flow.
• This system allows a flexible way, to collect the dust emitted by the ground.
• the circulation of air along the soil test tube reproduces the most frequent dust release conditions, namely the spontaneous release of dust under the effect of wind.
• various measurements can be performed on the dust collected by the collection system according to the invention.
• the quantities of dust collected can be determined, depending in particular on the diameter of the dust; the chemical composition of the dust, as well as all the other properties of it, can also be determined.
• the dust collection system is arranged to circulate the air along the free surface of the material, inside the enclosure: the air circulator is configured such that the air circulates globally in a direction parallel to the free surface of the material.
• the created air circulation thus reproduces the passage of the wind on the free surface of the material and thus makes it possible to reproduce or simulate the passage of the wind and thus the tearing of dust by the wind when this one blows on the surface of the material.
• the reverse dust collection system is configured to operate without air passing through the material.
• the material collection system is preferably designed to receive a specimen consisting mainly of a container closed on all sides, with the exception of the side on which is the free surface of the material.
• the free surface of the test piece is located upwards and is horizontal.
• the air circulation device is configured to circulate the air parallel to the free surface of the specimen, and therefore usually horizontally.
• the system uses a specimen of material.
• test piece of material means any container containing a sample of the material.
• the sample of material may be a soil sample, for example taken from the field, on site, or a sample of any material, whose dust emission properties are desired.
• the sample of material may or may not be or have been subjected to prior conditioning prior to the dust collection operation carried out by means of the system according to the invention.
• This conditioning (or this solicitation) can be performed or applied before and / or during the collection of dust.
• system further comprises a biasing device, adapted to apply to the material at least one of solicitation solicitation mechanical, chemical, and / or climatic. Many solicitations are possible.
• the system includes means for mechanical stressing of the material, in order to study the release of dust produced by mechanical stresses.
• the material is the material of a soil on which vehicles must travel, it is possible, for example, to perform a vehicle taxi simulation.
• a roller compactor can be used.
• the biasing device comprises a spraying device for projecting a rain of liquid on the free surface of the material.
• the spraying device then generally comprises one or more nozzles disposed above the surface of the sample.
• the spraying device may comprise a liquid reservoir and a pump. It can also be configured to be connected to a pressurized liquid distribution network.
• the biasing device comprises temperature control means, comprising in particular a radiator and / or an air conditioner.
• the air circulator includes a vacuum cleaner or an air compressor.
• the dust collector is a calibrated dust collector.
• it is a collector configured to collect calibrated dust, that is to say dust whose diameter falls within a range, a given interval (e). This interval may be bounded at one end or at both ends.
• the dust collector may for example comprise at least a calibrated mesh filter, or a plurality of calibrated mesh filters arranged in series.
• system further comprises, upstream of the free surface of the material, a turbulence generator.
• the dust collection system may also include different sensors, in order to measure and regulate the environmental conditions or the stresses applied to the sample of material.
• These sensors are generally arranged in the enclosure or in the vicinity of the latter, and as the case may be in the vicinity of the surface of the sample of material, and / or upstream and / or downstream from it.
• the system further includes a device for measuring air velocity.
• This measuring device may comprise a pitot tube, a propeller anemometer or the like.
• the system further comprises a device for measuring the surface tension of the material.
• the dust collection system according to the invention can serve in particular to measure the amounts of dust released by a material.
• a second object of the invention is a method for determining at least one property of a dust-release material. According to the invention, this method comprises the following steps: a) a test piece of soil containing a sample of the material is prepared;
• dust emission tests are carried out in a dust collection system as defined above, and dust generated by the material is collected during the tests carried out;
• At least one property of the dust thus collected is determined.
• This property can be simply the amount of dust collected, and / or any chemical property, mechanical (particle size), or other, dust collected with the aid of the dust collection system.
• This property of dust is a characteristic property of the material in terms of dust release.
• step b) the collection of dust in the dust collection system is carried out by carrying out tests, during which the soil test tube is subjected to environmental conditions (wind speed, temperature, hygrometry, precipitation (including a watering realized)) chosen.
• the process can naturally be implemented using several soil samples and not one, and / or more than one dust collection system and not one.
• the method defined above can in particular be used to optimize the soil watering operations performed to reduce dust emissions from the ground.
• a third object of the invention is a method of watering a soil, comprising the following steps:
• the material studied is a certain type of soil; as a result, the test piece used is a soil test tube.
• the dust collection system 10 comprises the system 10 comprising a chamber 20, a dust collector 40, and an air circulation device 60.
• the enclosure 20 is provided to receive a soil test piece 22.
• the test piece 22 is composed of a soil sample 24 and a container
• the container 26 is constituted by a rectangular parallelepiped-shaped metal container, filled by the soil sample 24. It is fixed on a support 28 arranged under the enclosure 20.
• the soil test piece 22 is arranged such that its upper surface, which includes the free surface 32 of the soil sample, is disposed inside the enclosure 20.
• the enclosure 20 consists mainly of four rigid rectangular flat panels, which define a rectangular section airflow passage. In Figure 1, for ease of understanding, these panels are shown as transparent, excluding the bottom panel 20i. The junction between these panels is provided by metal brackets 30.
• the soil test piece 22 is placed on the bottom panel 20i.
• the upstream face 20u of the enclosure 20 comprises a turbulence generator 34.
• This turbulence generator is constituted by a series of blades 36 of trapezoidal shape, between which the air can flow.
• the face or downstream section 20d of the enclosure 20 is open and opens on the dust collector 40.
• This collector consists essentially of a short rectangular section duct (the same section as the enclosure 20), sealingly connected to the downstream section 20d of the enclosure 20.
• This collector is a calibrated dust collector, which comprises means of selective collection of dust according to their diameter.
• a calibrated dust collector which comprises means of selective collection of dust according to their diameter.
• three dust filters 41, 42 and 43 calibrated mesh are fixed in this conduit.
• the meshes of these filters have respective dimensions of 300 ⁇ , ⁇ and 25 m.
• Dust collecting receptacles 45, 46 and 47 are disposed below each of these filters on the upstream side.
• the receptacle 45 thus collects dust of diameter greater than 300 ⁇
• the receptacle 46 the dust diameter between 300 and 100 ⁇
• the receptacle 47 the dust diameter between 100 and 25 ⁇ .
• the air circulation device 60 consisting mainly of an electric vacuum cleaner, serves to circulate air along the free surface 32 of the material sample (in this case soil) 24.
• suction portion 62 constituted by a casing in which a paddle wheel rotates to suck air, and a motor 64 which drives the impeller in rotation.
• the suction port 66 of the vacuum cleaner 60 is sealingly connected to the downstream outlet of the dust collector 40.
• the dust collection system 10 further comprises a biasing device 80. This device is used to bias the sample 24, to evaluate to what extent the dust emission by the material varies according to the applied stresses.
• the biasing system 80 is a sprinkler system for spraying water on the surface of the sample of material 24. It allows to create a drizzle or an artificial rain on it (as an example of climatic stress).
• the biasing system 80 thus comprises a reservoir and a pump contained in a housing 82.
• the discharge port of the pump is connected to a water distribution pipe 84. This is divided into different terminal ducts which allow the water discharged by the pump to be conveyed up to ten nozzles 88.
• the dust collection system 10 finally comprises measuring means 100. These comprise firstly an unrepresented balance, used to determine the mass of dust collected respectively by the different dust receptacles 45, 46 and 47.
• the enclosure 20 comprises different sensors arranged in the enclosure 20 or near it.
• the sensors disposed in the enclosure 20 are placed close to the free surface 32 of the sample 24 to provide measurements representative of the value of different quantities in the vicinity of this surface or for this surface.
• means for measuring the air circulation velocity above the surface 32 of the specimen 22 namely a propeller anemometer 102 and a Pitot tube 104;
• a differential pressure sensor This comprises two measuring members 106u, 106d placed respectively upstream and downstream of the chamber 20: thanks to these, the sensor supplies the pressure difference between the suction face 20u upstream and the section output 20d downstream of the enclosure 20.
• a surface tension sensor 108 for measuring the surface tension of the free surface 32 of the sample 24.
• the various sensors that comprise the measuring means 100 are connected to an electronic control unit 110.
• the pump of the spraying system 80 and the vacuum cleaner 60 are controlled by the control unit 110.
• the dust collection system 10 is implemented as follows.
• test pieces of soil 22 are prepared beforehand. These specimens contain representative samples of the soil (or material) whose dust emissions are to be quantified and qualified.
• dust collected by the material is collected during tests carried out in the dust collection system.
• a specimen 22 is placed on the support 28, so that the free surface of the sample is in the enclosure 20.
• the vacuum cleaner 60 is then actuated.
• the pressure drop generated by it causes air to circulate in the enclosure 20.
• the air enters the chamber passing between the blades 36 of the turbulence generator 34. Because of this, the air flow that passes above the test piece 22 is swirling.
• the spray device 80 is actuated. This causes rain to fall on the test piece 22 inside the enclosure.
• At least one property of the dust thus collected is determined.
• the dust collected by the different receptacles 45 to 47 are then weighed and analyzed chemically. This method of determining dust release properties of a material can be used to optimize watering operations.
• step a soil samples containing a soil sample are prepared.
• a series of dust release tests is then carried out (step b) using the soil test pieces. These tests extend over a period called test period. During the trial period:
• the vacuum cleaner 60 is actuated so that there is a relatively strong air flow in the enclosure 20, corresponding to a relatively strong wind;
• the specimen contained in the chamber 20 is sprinkled with the aid of the spraying system 60;
• the collected dust is collected in the receptacles 45-47.
• the dust thus collected is weighed (step c), taking into account their respective diameter ranges.
• an optimal watering program (step A) is determined, that is to say a watering program to maintain the amount of dust emitted below a maximum acceptable level (or other criterion) for a minimum price.

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• Life Sciences & Earth Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical & Material Sciences (AREA)
• General Health & Medical Sciences (AREA)
• Physics & Mathematics (AREA)
• Analytical Chemistry (AREA)
• Biochemistry (AREA)
• General Physics & Mathematics (AREA)
• Immunology (AREA)
• Pathology (AREA)
• Molecular Biology (AREA)
• Biomedical Technology (AREA)
• Engineering & Computer Science (AREA)
• Dispersion Chemistry (AREA)
• Sampling And Sample Adjustment (AREA)

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• 2015
  • 2015-12-17 FR FR1562619A patent/FR3045400B1/fr active Active
• 2016
  • 2016-12-12 WO PCT/FR2016/053327 patent/WO2017103402A1/fr not_active Ceased
  • 2016-12-12 EP EP16825477.9A patent/EP3391017A1/de not_active Withdrawn

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