APPARATUS FOR MEASURING TRACE IMPURITIES IN GAS STREAM Russian patent published in 2013 - IPC G01N15/00 

FIELD: chemistry.

SUBSTANCE: invention can be used independently in such tasks as inspecting articles and apparatus with the most stringent requirements for air-tightness, for example, heat exchangers of fast neutron reactors or inspecting high-efficiency filters (using iron pentacarbonyl as a tracer substance) and also as a chromatographic detector for monitoring atmospheric pollution by toxic organometallic compounds of the tetraethyllead type or when solving tasks for preventing unauthorised movement of hazardous substances and articles (using a set of organometallic compounds as tracers). The apparatus for measuring trace impurities in a gas stream has a converter for converting impurity molecules into molecular condensation nuclei, a device for activation thereof with an evaporator for the activating substance, a device for condensation enlargement of the activated molecular condensation nuclei into aerosol particles with an evaporator for the enlarging substance and a cooler. The apparatus also includes a photoelectric nephelometer for detecting aerosol particles. The devices for activation and condensation enlargement of molecular condensation nuclei are placed in one housing in form of a tube fitted with a side nozzle for inlet of the stream and a container for the enlarging substance which is connected to the tube by a capillary. The evaporator of the activating substance is placed at the inlet of the tube inside the evaporator of the enlarging substance in line with it to form an annular gap between them for passage of the gas stream, and the cooler is placed behind them in the outlet part of the tube. The evaporator of the enlarging substance is placed on the inner wall of the inlet part of the tube and is a thread made from cotton or carbon fibre which is wound on a cylinder made from wire mesh. The free end of the thread passes through a capillary into the container with the enlarging substance and servers as a wick for feeding the enlarging substance into the evaporator.

EFFECT: simple apparatus for measuring trace impurities in a gas stream, reduced cost thereof, mass and weight characteristics, power consumption and carrier gas consumption, reduced measurement error, enabling simultaneous determination of several substances in one sample.

5 dwg