Sampling rod for corrosive gases or fumes in an incinerator, particularly when installed on a ship

Claim 1

A sampling rod for corrosive gases or fumes in an incinerator comprising in a coaxial construction a central tube for the suction of gases made from a plastic material resistant to the corrosion by these high temperature gases, a first metallic tube forming a reinforcement for the central tube and enveloping the latter, a second metallic tube surrounding the first tube and defining with the latter an annular space traversed by a liquid fluid for the cooling of the gases circulating in the central tube and for maintaining said gases at an appropriate temperature, a layer of a thermally insulating material having a fibrous structure surrounding the second metallic tube and an outer jacket made from a refractory material which resists the mechanical and thermal shocks and ensures the distribution of the external heat in the insulating material, the space between the first and second metallic tubes traversed by the cooling fluid being separated into two annular and coaxial regions by an intermediate tube open at its end adjacent to that where the gases enter the central tube, whereby the cooling fluid is circulated in such a way that the outflow of said fluid firstly takes place in the annular region defined between the intermediate tube and the second metallic tube and then in the annular region between the intermediate tube and the first metallic tube, said two regions being connected respectively to a fluid supply tube and a fluid discharge tube at locations opposite to the end of the central tube via which the entry of the sampled gases takes place, the central tube extending axially beyond the two metallic tubes downstream of the cooling fluid supply and discharge tubes to issue into the casing of a compressed air pump thus creating in the central tube a suction vacuum of the gases to be sampled, an apparatus for analyzing the content of said gases, another tube extending to said analyzing apparatus and being connected to said central tube at a location upstream of the pump, a rocking support on which is articulated the sampling rod at its end opposite to that via which the gases pass into the central tube, and an extendable jack articulated on the rod to ensure the raising or substantially horizontal positioning of the latter with the end of the central tube in the sampling area.