초록 ▼

The invention relates to an improved sampling device for selectively collecting gaseous and aerosol pollutants contained in polluted air, said device being of the type comprising a cartridge provided with an inlet, an outlet and filtering means, a vacuum pump and means for connecting said pump to th

The invention relates to an improved sampling device for selectively collecting gaseous and aerosol pollutants contained in polluted air, said device being of the type comprising a cartridge provided with an inlet, an outlet and filtering means, a vacuum pump and means for connecting said pump to the outlet of the cartridge to cause some pulluted air to be drawn through said filtering means, the improvement wherein said filtering means consists of three successive filters and wherein: the first filter is made with a material of such a porosity that it collects aersol pollutants but is permeable to gas; the second filter is positioned downstream of the first filter and consists of a porous substrate impregnated with an effective amount of a chemical compound that reacts with one or more specific harmful or toxic gaseous pollutants to produce therefrom derivatives, said second filter being of such a porosity as to be permeable to air but not to said derivatives; and the third filter is positioned downstream of the second filter and consists of a porous material that is permeable to air and rigid enough to prevent deformation of the first and second filters. The invention also relates to a method using the above mentioned device.

대표청구항 ▼

In a sampling device for selectively collecting gaseous isocyanates and aerosol isocyanates that are contained in polluted air, said device being of the type comprising a cartridge provided with an inlet, an outlet and filtering means, a vacuum pump and means for connecting said pump to the outlet o

In a sampling device for selectively collecting gaseous isocyanates and aerosol isocyanates that are contained in polluted air, said device being of the type comprising a cartridge provided with an inlet, an outlet and filtering means, a vacuum pump and means for connecting said pump to the outlet of the cartridge to cause some polluted air to be drawn through said filtering means, the improvement wherein said filtering means consists of there successive filters and wherein: the first filter is made with polytetrafluoroethylene of such a porosity that it collects aerosol pollutants but is permeable to gas, the second filter is positioned downstream of the first filter and consists of a porous substrate impregnated with an effective amount of a secondary amine that reacts with the gaseous isocyanates to produce therewith urea derivatives, said second filter being of such a porosity as to be permeable to air but not to said derivative; and the third filter is positioned downstream of the second filter and consists of a porous material that is permeable to gas and rigid enough to prevent deformation of the first and second filters.