Gas-sampling probe and method for operating a gas-sampling probe

Patent metadata

Field	Value
Publication number	US-9915595-B2
Application number	US-201414913353-A
Country	US
Kind code	B2
Filing date	Jul 31, 2014
Priority date	Aug 19, 2013
Publication date	Mar 13, 2018
Grant date	Mar 13, 2018

Abstract

A method for operating a gas sampling probe includes removing a gas to be analyzed from a process space in the region of a front end of a gas sampling tube and conducting it through the gas sampling tube as far as a rear end and, in the process, cooling it by passing cooling air between the gas sampling tube and at least one outer casing enclosing the gas sampling tube. The cooling air is fed and discharged at the rear end of the gas sampling tube and the temperature of the gas to be analyzed is higher in the region of the front end of the gas sampling tube than the temperature of the fed cooling air, and the gas sampling probe emits outward, wherein the temperature of the fed cooling air is higher than the temperature of the discharged cooling air.

First claim

What is claimed is:

1. A method for operating a gas sampling probe, comprising:
removing a gas to be analyzed from a process space in a region of a front end of a gas sampling tube;
conducting the gas to be analyzed through the gas sampling tube to a rear end thereof; and
during said conducting step, feeding cooling air between an outer surface of the gas sampling tube and at least one outer casing enclosing the gas sampling tube, so as to simultaneously cool the gas to be analyzed that is conducted through the gas sampling tube, wherein the cooling air is fed and discharged at the rear end of the gas sampling tube and a temperature of the gas to be analyzed is higher in the region of the front end of the gas sampling tube than a temperature of the fed cooling air, and wherein the gas sampling probe at least near the rear end of the gas sampling tube emits thermal energy outward, and wherein the temperature of the fed cooling air is higher than a temperature of the discharged cooling air.

2. The method of claim 1 , wherein the cooling air is conducted from the rear end to the front end of the gas sampling tube and back to the rear end.

3. The method of claim 1 , wherein the cooling air is conducted in a circuit.

4. The method of claim 3 , wherein the temperature of the discharged cooling air is measured and an air heater is actuated depending on the temperature measured such that the temperature of the cooling air conducted in the circuit is at a prescribed setpoint value in a region where the cooling air is fed at the rear end of the gas sampling tube.

5. The method of claim 1 , wherein the temperature of the discharged cooling air is increased before the discharged cooling air is fed again.

6. The method of claim 1 , wherein the gas to be analyzed is cooled from the front end to the rear end of the gas sampling tube at most to a minimum temperature that is greater than or equal to a dew point temperature of components contained in the gas to be analyzed.

7. The method of claim 1 , wherein the temperature of the fed cooling air is higher at the rear end of the gas sampling tube than the temperature of the gas to be analyzed at the rear end of the gas sampling tube, wherein the temperature of the discharged cooling air is less than or equal to the temperature of the gas to be analyzed at the rear end of the gas sampling tube.

8. The method of claim 1 , wherein a temperature profile of the gas sampling tube along its entire length is set such that a minimum temperature is greater than or equal to a dew point temperature of components contained in the gas to be analyzed.

9. The method of claim 1 , wherein the temperature of the discharged cooling air is increased by at least 20° C. before the discharged cooling air is fed again.

10. The method of claim 1 , wherein the temperature of the fed cooling air is set in a range from 100° C. to 600° C. in a region of the rear end of the gas sampling tube.

11. The method of claim 1 , wherein the temperature of the gas removed and to be analyzed is cooled by at least 50% from the front end to the rear end of the gas sampling tube.

12. The method of claim 1 , wherein the temperature of the discharged cooling air is less than or equal to a temperature of the gas sampling tube in a region of the rear end of the gas sampling tube.

13. The method of claim 1 , wherein the gas sampling probe is arranged at the process space such that the gas sampling probe absorbs external heat in a front region and emits heat in a rear region, wherein in an overall heat balance the gas sampling probe emits more heat than the gas sampling probe absorbs.

14. The method of claim 1 , wherein a difference between heat absorbed and heat emitted by the gas sampling probe corresponds to a sum of a cooling heat of the gas to be analyzed and of the cooling air.

15. A gas sampling device comprising:
a gas sampling probe that has a gas sampling tube for removing a gas to be analyzed in a region of a front end of the gas sampling tube and to conduct the gas to be analyzed through the gas sampling tube as far as a rear end of the gas sampling tube, wherein the gas sampling tube is enclosed by at least one outer casing, which forms a cooling zone that extends along a length of the gas sampling tube, said cooling zone having in a region of the rear end of the gas sampling tube a cooling-air feed opening for feeding cooling air into the cooling zone and a cooling-air discharge opening for discharging the cooling air from the cooling zone, wherein the gas sampling probe at least near the rear end of the gas sampling tube emits thermal energy outward, wherein the cooling-air discharge opening and the cooling-air feed opening are connected to form a closed circuit and an air heater for increasing a temperature of the discharged cooling air is disposed between the cooling-air discharge opening and the cooling-air feed opening.

16. The gas sampling device of claim 15 , wherein the gas to be analyzed is removed from a process space, wherein the gas sampling probe is arranged at the process space such that the gas sampling probe forms a heat absorption region in a front region of the gas sampling probe and a heat emission region in a rear region of the gas sampling probe.

17. The gas sampling device of claim 15 , wherein the air heater is connected to a control device that actuates the air heater in dependence on a temperature signal from a temperature measuring device, wherein the temperature measuring device senses the temperature of the discharged cooling air.

18. The gas sampling device of claim 15 , wherein the cooling zone formed between the gas sampling tube and the outer casing is divided into two halves that extend along the length of the gas sampling tube, said two halves being connected in a front region of the gas sampling probe via an overflow region and the cooling-air feed opening and the cooling-air discharge opening each being disposed on one of the two halves in a rear region of the gas sampling probe.

19. The gas sampling device of claim 15 , wherein the cooling zone formed between the gas sampling tube and the outer casing has two annular spaces that are arranged concentrically with one another, said two annular spaces being connected in a front region of the gas sampling probe via an overflow region, and the cooling-air feed opening and the cooling-air discharge opening are each disposed on one of the two annular spaces in a rear region of the gas sampling probe.

20. A gas sampling device comprising:
a gas sampling tube for conducting a gas to be analyzed from a region near a front end of the gas sampling tube to a rear end of the gas sampling tube;
an outer casing that encloses the gas sampling tube such that a cooling zone exists between the outer casing and the gas sampling tube, wherein the cooling zone has in a region of the rear end of the gas sampling tube a cooling-air feed opening for feeding cooling air into the cooling zone and a cooling-air discharge opening for discharging the cooling air from the cooling zone, wherein the cooling-air discharge opening and the cooling-air feed opening are connected and form a part of a circuit through which the cooling air flows; and
a heater for increasing a temperature of the cooling air that is discharged before the cooling air is fed into the cooling-air feed opening, the heater being disposed between the cooling-air discharge opening and the cooling-air feed opening.

Assignees

• Thyssenkrupp Ind Solutions Ag

Inventors

• Könning Ludwig
• Streffing Michael
• Bredemeier Heinz
• Leuer Alfons

Classifications

• G01N1/22 Primary

  in the gaseous state {(specially adapted for biological material G01N33/497; measuring breath flow A61B5/087)} · CPC title

• G01N1/42 Primary

  Low-temperature sample treatment, e.g. cryofixation · CPC title

• G01N33/0016

  by regulating a physical variable, e.g. pressure or temperature · CPC title

• G01N2001/2282

  with cooling means · CPC title

• G01N1/24

  Suction devices {(G01N1/22 - G01N1/2294 take precedence)} · CPC title