Sampling of gaseous atmospheres

Claim 2

A gas-sampling probe comprising a sampling tube having a closed inner end for insertion in an atmosphere to be sampled, the tube being formed with lateral openings near said closed inner end for communication with the atmosphere, a steam supply line extending axially within said sampling tube, a nozzle block within the sampling tube and at least partly disposed opposite said lateral openings, which nozzle block comprises a nozzle plate fitted on the steam supply line and formed with a plurality of ejector nozzles spaced in an annular array surrounding the steam supply line, and a cap fixed to the nozzle plate and defining therewith an internal chamber communicating with the steam supply line and with said annular array of nozzles, the external surface of the nozzle block opposite each said lateral opening being recessed to provide a clearance between the nozzle block and the internal surface of the sampling tube at each said lateral opening.

Claim 3

A probe according to claim 1, wherein the cap has an internal concave surface facing the nozzle plate.

Claim 4

A probe according to claim 1, including a filter and a drier through which steam is supplied to the steam supply line, so that steam supplied is substantially free of particles and water.

Claim 5

A probe according to claim 1, including a shut-off valve communicating with said sampling tube for shutting off the flow of steam and entrained gas through the tube.

Claim 6

A probe according to claim 4, including means for closing said shut-off valve automatically for predetermined intervals of time at separated times during operation of the probe.

Claim 7

The method according to claim 6 and further including the step of: circulating cooling water entirely around the portion of the sampling tube positioned within the atmosphere.

Claim 8

A gas-sampling probe comprising: a sampling tube having a closed inner end, at least the closed-end portion of said tube being adapted to be inserted in an atmosphere to be sampled, the tube being formed with at least one lateral opening near said inner end for communication with said atmosphere; a steam supply line extending into said tube and being directed toward said closed inner end from within said tube, said steam supply line terminating in the region of said lateral opening; and a reverse-steam ejection nozzle block positioned at the end of said steam line in the region of said at least one lateral opening, said nozzle block having at least one steam ejector nozzle communicating with said steam line and being directed into said tube away from said inner end in a direction generally parallel to and opposite the direction of steam flow through said steam line; said at least one lateral openIng being positioned adjacent the outlet portion of said at least one nozzle such that steam ejected from said at least one nozzle causes a pressure reduction at said at least one lateral opening to draw atmosphere into the sampling tube.

Claim 9

A gas-sampling probe comprising: a sampling tube having a closed inner end, at least the closed-end portion of said tube being adapted to be inserted in an atmosphere to be sampled, the tube being formed with at least one lateral opening near said inner end for communication with said atmosphere; a steam supply line extending into said tube and being directed toward said closed inner end from within said tube, said steam supply line terminating in the region of said lateral opening; and a reverse-steam ejection nozzle block positioned at the end of said steam line in the region of said at least one lateral opening, said nozzle block having at least one steam ejector nozzle communicating with said steam line and being directed into said tube away from said inner end in a direction generally parallel to and opposite the direction of steam flow through said steam line; said at least one lateral openIng being positioned adjacent the outlet portion of said at least one nozzle such that steam ejected from said at least one nozzle causes a pressure reduction at said at least one lateral opening to draw atmosphere into the sampling tube.

Claim 12

A probe according to claim 8 wherein the portion of said sampling tube positioned in said atmosphere has a substantially constant cross-section throughout its length.

Claim 13

A probe according to claim 9 wherein a cooling jacket is provided completely surrounding the portion of the sampling tube located within the atmosphere, the cooling jacket having a substantially constant annular cross-section throughout the length thereof positioned within the atmosphere; and an atmosphere inlet pipe is provided extending through the jacket from said lateral opening.

Claim 14

A probe according to claim 8, comprising a cooling jacket surrounding the tube and having an inlet and an outlet for coolant fluid spaced from said inner end of the sampling tube, and an atmosphere inlet pipe extending through the jacket from said lateral opening.

Claim 15

A probe according to claim 11, wherein the cooling jacket comprises two coaxial tubular walls defining inner and outer passages of annular cross-section, said passages communicating with each other at the inner end of the sampling tube, and respective coolant fluid connections communicating with the inner and outer passages remotely from said inner end.

Claim 16

A probe according to claim 8, wherein the nozzle block is formed with an internal chamber communicating centrally with the steam supply line, and includes a nozzle plate constituting one wall of the chamber and formed with a plurality of ejector nozzles spaced apart in an annular array surrounding the steam supply line, which nozzles communicate with the internal chamber.

Claim 17

A probe according to claim 13, the nozzle block is formed with an internal concave end wall facing the nozzle plate.