Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
  • G01N33/0004—Gaseous mixtures, e.g. polluted air
  • G01N33/0009—General constructional details of gas analysers, e.g. portable test equipment
  • G01N33/0027—General constructional details of gas analysers, e.g. portable test equipment concerning the detector
  • G01N33/0036—General constructional details of gas analysers, e.g. portable test equipment concerning the detector specially adapted to detect a particular component
  • G01N33/0059—Avoiding interference of a gas with the gas to be measured
  • G01N33/006—Avoiding interference of water vapour with the gas to be measured
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
  • G01N33/0004—Gaseous mixtures, e.g. polluted air
  • G01N33/0009—General constructional details of gas analysers, e.g. portable test equipment
  • G01N33/0011—Sample conditioning
  • G01N33/0016—Sample conditioning by regulating a physical variable, e.g. pressure or temperature
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
  • G01N33/0004—Gaseous mixtures, e.g. polluted air
  • G01N33/0009—General constructional details of gas analysers, e.g. portable test equipment
  • G01N33/0011—Sample conditioning
  • G01N33/0018—Sample conditioning by diluting a gas

Definitions

• the present invention relates to a device for detecting a concentration of polluting compounds in a gaseous effluent, comprising a measurement indicator.
• FID Fluorescence Detector
• PID Photo-Ionization Detector
• FID resources use hydrogen as an oxidizer, which requires the use of a specific room.
• PID means do not use hydrogen, but can only be used on effluents at room temperature.
• the object of the invention is, in view of the above, to propose a solution which makes it possible to continuously measure a concentration of pollutant in a sample of gaseous effluent with a low maintenance cost.
• the object of the invention is, in view of the foregoing, to propose a solution which makes it possible to continuously measure a concentration of pollutant in the gaseous effluents of a complete industrial installation, while maintaining the measurement performance over time.
• the object of the invention is also to make more precise, to facilitate and to make faster the measurement of such a concentration of pollutant.
• the invention also relates to an easy and quick maintenance measuring device, of robust structure and adaptable to any type of gaseous effluent, whatever its temperature and its humidity.
• the measuring device makes it possible to measure a concentration of polluting compounds in a gaseous effluent.
• the device comprises a measurement indicator, as well as a semiconductor detector capable of continuously analyzing a measurement sample of the gaseous effluent.
• the device comprises means for maintaining the temperature of the measurement sample above the dew point.
• the means for maintaining the temperature of the measurement sample above the dew point include a temperature regulation probe, a heating resistor, a temperature regulator, and a thermally insulated enclosure.
• the device comprises means for filtering the measurement sample to remove solid particles present in the gas sample.
• the semiconductor detector device comprises a dilution air circuit, treated with activated carbon, and capillaries, maintained in depression by an air pump and placed upstream of the semiconductor detector.
• the device is part of a device for measuring a concentration of pollutant in gaseous effluents flowing in a plurality of conduits circulation, comprising measuring means and a plurality of nozzles, connected to the conduits and associated with a vacuum means, each nozzle being connected to the semiconductor detector device by a common extraction conduit and comprises a metal filter cartridge frit.
• the vacuum means comprises a vacuum pump capable of maintaining a constant vacuum and a regulated sonic flow rate on each nozzle, the vacuum pump being connected to the common extraction duct.
• each nozzle is connected to a circulation pipe for one of the gaseous effluents by means of a water spillway.
• the vacuum pump is equipped with a heated stainless steel body.
• the method for measuring a concentration of polluting compounds in a gaseous effluent consists in that a gaseous effluent is continuously measured and that a semiconductor detector device is used.
• the concentration of polluting compounds measured is representative of the concentration of volatile organic compounds in the gas sample.
• a plurality of individual gas samples are continuously sampled, and a gaseous effluent representative of all the samples taken by a semiconductor detector device is continuously analyzed.
• the flow rate of each individual sample is kept constant, and each of these flow rates is kept proportional to the fraction of the flow rate of the gaseous effluent from which the sample in question comes in relation to the total flow of all of the gaseous effluents, so that the gas stream analyzed is representative of all of the gaseous effluent flows.
• the volatile organic compounds of the gas sample come from an industrial painting installation.
• FIG. 1 is a block diagram of a measuring device according to the invention.
• FIG. 2 is a diagram of a sampling nozzle and its base or water spout.
• FIG. 3 is a block diagram of a semiconductor detector device which can be used in a device according to the invention.
• FIG. 1 there is shown the general architecture of a multi-point sampling device, here nine in number, for the continuous measurement of a rate of particles in effluents gas from an industrial installation, for example a painting installation.
• different conduits 1 can be placed along the painting installation by following the movement of the treated objects.
• a nozzle 3, preferably a sonic nozzle, with a sintered metal filter cartridge, is mounted on each gaseous effluent pipe 2, by means of a water evacuator 4.
• sintered metal use may in particular be made of PINOX 316L or a non-oxidizable metal, under normal conditions of use.
• FIG. 1 shows a nozzle 3 of the sampling device which comprises a water evacuator 4 or base, mounted on a conduit 1 in which the gaseous effluent flows 2.
• the water evacuator 4 is fixed on this conduit 1 by means of its base 10 which includes an opening 11 common with the conduit 1.
• the water spillway 4 comprises a flat surface 12 making an angle between 45 ° and 60 ° with the axis of the conduit 1, and a circular opening 13 in the surface plane 14, on which the nozzle 3 is fixed.
• the nozzle 3 is fixed to the plane surface 14 by means of a base 15, several screws 16, and a seal 17, its axis 18 making an angle about 10 ° to 15 ° with the axis of the duct 1.
• a cylindrical envelope 19 surrounds the c filter cartridge 20 of sintered metal, which has a passage 20a and a cylindrical wall of sintered metal 20b on the inner cylindrical periphery.
• the envelope 19 is connected to a cylindrical envelope 21 by a junction 22.
• the cylindrical envelope 21 surrounds a junction stage 23.
• a divergent nozzle 24 connects the junction stage 23 to an individual conduit 5.
• the semiconductor detector device 8, visible in FIG. 1 is shown in more detail in FIG. 3, and comprises a detector 25, for example a semiconductor detector, for example of the NAP-11AS type.
• This device comprises an inlet 26 for the sample, connected to the outlet 9 for the pump 7 (FIG. 1), a filter 27 for sample air, a capillary 28 placed upstream from the detector 25 connecting the outlet for the filter 27 at the inlet of the detector 25, and a capillary 29 placed upstream of the detector 25 connecting the outlet of a dilution air filter 30 to the inlet of the detector 25. It also includes dilution circuit 31, and an activated carbon filter 32.
• the semiconductor detector device 8 further comprises an air pump 33 connected to the detector 25 as well as to a pressure regulator 34.
• the detector device 8 also comprises a temperature regulation probe 37 and a heating resistor 36 connected to a temperature regulator 37 by connections not shown, as well as an electrical protection 38, an indicator 39 for measuring the level of particles of the sample, and a power supply stabilized 40.
• the detector device 8 is mounted inside a heat-insulated enclosure 41.
• the system composed of a sonic nozzle 3 with a sintered metal filter cartridge and a water drainer 4, makes it possible to continuously extract a sample from this gaseous effluent 2.
• a small part of the gas stream 2 enters the water evacuator 4 through the opening 11 of the base 10, then into the filter cartridge 20 through the opening 13.
• the water evacuator 4 makes it possible to have a gas extract as least humid as possible.
• the water droplets indeed condense on contact with the inclined wall 12.
• the gas flow then passes through the passage 20a of the filter cartridge 20, the layer 20b of sintered metal capturing the particles with which the effluent is charged.
• the gas flow then crosses the divergent nozzle 24 before exiting through the individual conduit 5.
• the nozzle 24 and the depression created downstream of the nozzle by the pump 7 are chosen so as to maintain a sonic flow in the nozzle 3.
• the filter cartridge 20 makes it possible to filter the particles contained in the gas stream and unlike the known filters which clog in a duration of the order of an hour, this can operate without clogging for much longer periods, from around 1 to 10 months. It is thus possible to carry out a continuous measurement.
• the flows extracted from each nozzle 3 arrive in their respective individual conduit 5, and meet in the common extraction conduit 6.
• the circulation of the gaseous samples which mix is ensured by the vacuum pump 7.
• the pump 7 has a stainless steel body, so as not to be attacked by corrosive elements.
• the pump body is advantageously heated to limit condensation.
• the sample representative of all the rejects from the industrial installation is analyzed by the semiconductor detector device 8.
• the objective of our embodiment is to continuously measure concentrations of pollutants, significantly different upstream and downstream of the industrial facility.
• the analysis sample enters the measuring device 8 through the inlet 26, and passes through the filter 27 in order to remove the particles present in the gas sample.
• the outlet of the filter 27 is calibrated and makes it possible to regulate the flow rate in the capillary 28.
• the activated carbon filter 32 makes it possible to filter the air in the dilution circuit 31, in particular retaining any traces of compound to be analyzed, so as not to deteriorate the analysis sample.
• the particles possibly present in the dilution air are eliminated by the filter 30.
• the outlet of the filter 30 is calibrated and makes it possible to regulate the flow rate in the capillary 29.
• the surface of the semiconductor detector 25 is covered with a very thin layer of metal oxides on a ceramic substrate.
• the electrical resistance of the detector 25 varies as a function of the quantity of molecules of organic compounds in contact with the detector 25 and as a function of the type of metal oxides used.
• the air pump 33 and the pressure regulator 34 make it possible to maintain the depression of the chamber of the semiconductor detector 25.
• the depression produced in the chamber of the detector 25 makes it possible to decontaminate the detector 25 during the drop in concentration of the compounds organic, and thus allows an increased operating time.
• the assembly formed by the temperature regulation probe 35, the heating resistor 36, the temperature regulator 37, and the heat-insulated enclosure 41, makes it possible to maintain the device at a temperature above the dew point of the sample, in order to avoid partial or total condensation of the gas sample to be analyzed.
• the semiconductor detector device 8 is electrically powered by the stabilized power supply 40, and electrically protected by the electrical protection 38.
• the analysis result is displayed on the analysis indicator 39.
• the invention makes it possible to carry out a continuous analysis of a concentration of pollutant in gaseous effluents, in particular from an industrial installation, on a final sample representative of all the discharges from the production area.
• the invention also makes it possible to reduce the number of measuring devices, since a single representative final sample is measured, and therefore to significantly reduce the measurement costs.
• the invention also makes it possible to obtain an easy and rapid maintenance device, robust, and adaptable to any type of gaseous effluent, whatever its temperature and its humidity level.
• the results of the concentration of a mixture of organic compounds obtained by a measurement device comprising a semiconductor detector follow, on a time scale, the same evolution as the results obtained with another type of more precise analyzer, but more expensive, such as a flame ionization detection analyzer.
• the measuring device according to the invention makes it possible to obtain a variation of organic compounds while keeping a low maintenance cost.
• the invention makes it possible to continuously measure a concentration of a mixture of compounds in a gaseous sample, while maintaining this above the dew point.
• the invention also makes it possible to obtain high measurement accuracy, by filtering the particles of the gas sample and of the air of the dilution circuit, as well as by eliminating any traces of the compound to be measured from the air of dilution, while keeping the maintenance cost low.

Landscapes

• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Health & Medical Sciences (AREA)
• Medicinal Chemistry (AREA)
• Food Science & Technology (AREA)
• Combustion & Propulsion (AREA)
• Physics & Mathematics (AREA)
• Analytical Chemistry (AREA)
• Biochemistry (AREA)
• General Health & Medical Sciences (AREA)
• General Physics & Mathematics (AREA)
• Immunology (AREA)
• Pathology (AREA)
• Sampling And Sample Adjustment (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=33420817

Family Applications (1)

Country Status (2)

Families Citing this family (2)

Family Cites Families (7)

• 2004
  • 2004-04-09 EP EP04742469A patent/EP1616175A2/de not_active Withdrawn
  • 2004-04-09 WO PCT/FR2004/000883 patent/WO2004097399A2/fr not_active Ceased

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events