Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
  • G01M3/00—Investigating fluid-tightness of structures
  • G01M3/02—Investigating fluid-tightness of structures by using fluid or vacuum
  • G01M3/04—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point
  • G01M3/20—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using special tracer materials, e.g. dye, fluorescent material, radioactive material
  • G01M3/202—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using special tracer materials, e.g. dye, fluorescent material, radioactive material using mass spectrometer detection systems
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
  • G01M3/00—Investigating fluid-tightness of structures
  • G01M3/02—Investigating fluid-tightness of structures by using fluid or vacuum
  • G01M3/04—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point
  • G01M3/20—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using special tracer materials, e.g. dye, fluorescent material, radioactive material
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N1/00—Sampling; Preparing specimens for investigation
  • G01N1/02—Devices for withdrawing samples
  • G01N1/22—Devices for withdrawing samples in the gaseous state
  • G01N1/2202—Devices for withdrawing samples in the gaseous state involving separation of sample components during sampling
  • G01N1/2205—Devices for withdrawing samples in the gaseous state involving separation of sample components during sampling with filters
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N1/00—Sampling; Preparing specimens for investigation
  • G01N1/02—Devices for withdrawing samples
  • G01N1/22—Devices for withdrawing samples in the gaseous state
  • G01N1/24—Suction devices

Definitions

• the invention relates to a sniffer probe for Gaslecksuche.
• Sniffer probes are used in gas leak detection to test for a possible gas leak with a gas-filled specimen.
• the sniffer probe is guided along the outside of the specimen and sucks (sniffs) gas from the outside of the specimen.
• the gas leaving the sample through the leak is also taken up and analyzed in a subsequent gas detector.
• the gas detector is typically designed to detect various types of gas and in particular the gas exiting the sample. It is known to provide sniffer probes with a suction gas line and with a sample gas line branching off from the suction gas line.
• the suction gas line leads from a suction gas inlet to a suction gas outlet connected to a suction device
• the sample gas line branches off from the suction gas line and has at its end opposite the branch a measurement gas outlet which can be connected to the gas detector.
• a sniffer probe is described, for example, in WO 2009 / 033978 A. While the suction device generates, for example in the form of a strong vacuum pump or a fan, a comparatively large mass flow rate in the suction gas line, a partial flow is taken with the aid of the sample gas line from this mass flow rate and fed to the gas detector. With this sniffer probe, it is possible to detect gas leaks even at long distances using a large intake mass flow rate by the gas detector is supplied only the required partial flow of the drawn mass flow.
• particulate filters are used in the gas-carrying lines to protect the gas delivery system and sensors from contamination and blockage.
• To ensure adequate protection conventionally several filter stages must be used one after the other to filter the total flow of the soaked air.
• one difficulty is that with increasing gas quantity of the sucked-in gas flow, the degree of soiling also increases, so that the larger the gas flow, the faster the filters become clogged.
• the conventional type of gas filtration thus represents a limiting factor in increasing the intake gas volume flow.
• the invention has for its object to provide a sniffer probe that can suck a large gas flow rate and has an improved gas particle filter.
• the sniffer probe according to the invention is defined by the features of claim 1.
• the measuring gas inlet forming the branching of the measuring gas line from the suction gas line has a measuring gas filter arranged in such a way that the suction gas flow guided through the suction gas line in the direction of the suction gas outlet is guided along the surface of the measuring gas filter.
• the sample gas filter is thus not flowed through by the suction gas flow sucked in in total by the sniffer probe, but only by the partial flow guided through the sample gas line to the gas detector.
• the suction gas flow is guided along the surface of the sample gas filter and the suction gas stream leads from the sample gas filter filtered particles.
• the suction gas stream thus cleans and regenerates the sample gas filter without having to remove the sample gas filter and interrupting the operation of the sniffer probe.
• the sample gas filter does not settle as fast as in the conventional filtration of the total intake gas flow. The intervals between the replacement of the gas filter can be considerably extended.
• the sample gas filter advantageously forms the inner wall of the suction gas line in the region of the branch in order to achieve particularly favorable flow conditions.
• the sample gas filter may be formed cylindrically over the entire circumference of the inner wall. It is conceivable to provide an annular gap radially outside the sample gas filter which is connected to the sample gas line. Such an arrangement is particularly in a plate-shaped "Carpet sample”. advantageous. Even with such a sniffer probe, the majority of the sucked air flow is blown directly and unfiltered again and diverted only a partial flow and fed to the gas detector.
• the measurement gas filter at least partially radially from the inside is flowed through to the outside of the sample gas stream to remove particles collected by the sample gas filter particles from the suction gas flow.
• the mass flow rate of the suction gas stream in the flow direction before the branching of the sample gas line is between 2,000 sccm and 4,000 sccm and particularly preferably about 3,000 sccm.
• the volume flow of the sample gas stream is between 200 sccm and 400 sccm, and more preferably about 300 sccm.
• about is meant a deviation of at most about ⁇ 10%.
• the proportion of the sample gas flow to the sucked suction gas flow may be about 10%.
• this proportion is in the range between 0.5 times to 0.01 times the sucked suction gas mass flow.
• the gas inlet may be provided with an inlet filter whose pore size is sufficiently coarse in order not to significantly affect the intake mass flow and to avoid rapid clogging of the filter, in the area behind the branch of Meßgasieitung the suction gas may have in the flow direction of a suction gas filter, the allows a large flow of gas and not appreciably affected.
• To this filter may be connected, for example, led to a pump capillary or hose-like supply of the suction gas stream.
• Fig. 2 the second embodiment.
• the sniffer probe 10 has a suction gas line 12 and a sample gas line 14 branching from the suction gas line 12.
• the suction gas pipe 12 is provided at its one end with a suction gas inlet 16 for sucking the gas.
• the suction gas line 12 is provided with a suction gas outlet 18 which serves to connect a suction device 20.
• the suction device 20 is a vacuum pump.
• the suction device 20, which is not shown in the figure for the sake of simplicity, may be a fan or a pump.
• the sample gas line 14 branches off from the suction gas line 12.
• the sample gas line 14 is provided with a sample gas inlet 22 at its end connected to the suction gas line 12 and with a sample gas outlet 24 at its end opposite the sample gas inlet 22.
• the sample gas outlet 24 serves to connect a sample gas detector.
• the measurement gas detector which is not shown in the figures for the sake of simplicity, can each be a mass spectrometer or other selective gas detection system.
• the sample gas inlet 22 forms the branch 26 of the sample gas line 14 from the suction gas line 12.
• the sample gas inlet 22 is provided with a sample gas filter 28.
• the measuring gas filter 28 is tubular in each case, with the inside of the measuring gas filter 28 forming the inner wall 30 of the suction gas line 12 in the region of the branch 26.
• the suction device 20 draws in through the suction gas inlet 16 to a suction gas flow of about 3,000 sccm.
• the suction gas flow is guided along the inside of the sample gas filter 28 in the axial direction of the suction gas line 12 to the Sauggasauslass 18 and fed from there to the suction device 20.
• a partial flow branches off from the suction gas stream, which flows through the sample gas inlet 22 and through the sample gas filter 28 into the Sample gas line 14 flows in.
• This partial flow is the sample gas flow which is supplied through the sample gas line 14 and the sample gas outlet 24 to the gas detector, not shown in the figures. Gas fractions present in the sample gas stream are detected by the gas detector.
• the sample gas filter 28 prevents intrusion of interfering particles or contaminants into the sample gas line 14. The particles collected by the sample gas filter 28 are removed from the comparatively strong suction gas flow and transported in the direction of the suction gas outlet 18.
• FIG. 1 is a sniffer corner finder with a hand-held sniffer tip.
• the suction gas inlet 16 is provided with an inlet filter 32 and the suction gas outlet with an outlet filter 34.
• the two filters 32, 34 are coarsely porous filters to collect only coarse particles, while the sample gas filter 28 is a fine-pored filter.
• the filters 32, 34 affect the suction gas flow only negligible.
• the sniffer probe 10 is a so-called "carpet sample", which has a large-area suction plate 36 in whose center the suction gas line 12 branches off and has its suction gas inlet 16. Radially outside the sample gas filter 28, an annular gap 38 is formed. The sample gas stream branched off from the suction stream flows radially from the inside to the outside through the sample gas filter 28 and is subsequently supplied in the circumferential direction through the annular gap to the sample gas line 14, which is gas-conductively connected to the gap 38.
• the sample gas line 14 has a flow restrictor 40 for restricting flow and is connected to a vacuum pump 42, which forms part of the gas detector.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Examining Or Testing Airtightness (AREA)
• Other Investigation Or Analysis Of Materials By Electrical Means (AREA)
• Measuring Volume Flow (AREA)
• Sampling And Sample Adjustment (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=51383719

Family Applications (1)

Country Status (6)

Cited By (2)

Families Citing this family (8)

Citations (2)

Family Cites Families (9)

• 2013
  • 2013-08-29 DE DE201310217279 patent/DE102013217279A1/de not_active Withdrawn
• 2014
  • 2014-08-18 CN CN201480046484.1A patent/CN105556271A/zh active Pending
  • 2014-08-18 WO PCT/EP2014/067584 patent/WO2015028336A1/de not_active Ceased
  • 2014-08-18 EP EP14753063.8A patent/EP3039395B1/de active Active
  • 2014-08-18 JP JP2016537222A patent/JP6389524B2/ja active Active
  • 2014-08-18 US US14/912,526 patent/US20160202138A1/en not_active Abandoned

Patent Citations (2)

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