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

Patent metadata

Field	Value
Publication number	US-2016209306-A1
Application number	US-201414913353-A
Country	US
Kind code	A1
Filing date	Jul 31, 2014
Priority date	Aug 19, 2013
Publication date	Jul 21, 2016
Grant date	—

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

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; during said conducting step, feeding a flow of 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 the temperature of the fed cooling air, and wherein the gas sampling probe emits outward, and wherein a temperature of the fed cooling air is higher than the temperature of the discharged cooling air.

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

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

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

5 . 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 a circuit is at a prescribed setpoint value in the region of the feed at the rear end of the gas sampling tube.

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

8 . The method of claim 1 , wherein the temperature profile of the gas sampling tube along its entire length is set such that the minimum temperature is greater than or equal to the dew point temperature of the 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 it 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 the region of the rear end of the gas sampling tube.

11 . The method of claim 1 , wherein the temperature of the gas to be analyzed is between 200° C. and 1600° C. prior to removal.

12 . 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 to the rear end of the gas sampling tube.

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

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

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

16 . A gas sampling device for carrying out the method of claim 1 , comprising:
a gas sampling probe which has a gas sampling tube in order to remove a gas to be analyzed in the region of a front end and to conduct it through the gas sampling tube as far as a rear end, wherein the gas sampling tube is enclosed by at least one outer casing such that a cooling zone that extends along the length of the gas sampling tube is formed, said cooling zone having a cooling-air feed opening and a cooling-air discharge opening in the region of the rear end of the gas sampling probe, wherein the gas sampling probe emits outward, wherein the cooling-air discharge opening and the cooling-air feed opening are connected together to form a closed circuit and an air heater is provided between the cooling-air discharge opening and the cooling-air feed opening.

17 . The gas sampling device of claim 16 , wherein the gas sampling probe is arranged at the process space such that it forms a heat absorption region in a front region and a heat emission region in a rear region.

18 . The gas sampling device of claim 16 , wherein the air heater is connected to a control device which actuates the air heater in dependence on a temperature signal from a temperature measuring device wherein the temperature measuring device senses the temperature of cooling air discharged via the cooling-air discharge opening.

19 . The gas sampling device of claim 16 , 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 halves being connected together in the 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 provided on one of the two halves in the rear region of the gas sampling probe.

20 . The gas sampling device of claim 16 , 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 annular spaces being connected together in the 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 provided on one of the two annular spaces in the rear region of the gas sampling probe.

Assignees

• Thyssenkrupp Ind Solutions Ag

Inventors

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

Classifications

• G01N33/0016

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

• 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

• G01N1/24

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

• G01N1/2258 Primary

  in a stack or chimney · CPC title