Method and apparatus for nitrogen oxide determination
First Claim
1. Fluid sampling apparatus which comprises:
- a. a fluid inlet conduit including means for fluid connection to a source containing fluid to be sampled;
b. an aspirator device having a suction inlet opening for the fluid to be sampled, a motive fluid inlet opening, and an exit opening;
c. a restrictive flow conduit in fluid communication with said inlet conduit and with the section inlet opening of said aspirator device;
d. a motive fluid inlet conduit in fluid communication with the motive fluid inlet opening of said aspirator device, said motive fluid inlet conduit including means for connection to a source of motive fluid for creating a dilute mixture of motive fluid and sample fluid, said motive fluid inlet capable of providing variable dilution ratios of sample fluid to motive fluid;
e. first heating means at said restrictive flow conduit for heating a sample of fluid passing therethrough;
f. second heating means at said motive fluid inlet conduit for heating motive fluid passing therethrough;
g. a discharge conduit in fluid communication with said aspirator device exit opening for discharging the diluted mixture of motive fluid and sample fluid.
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Accused Products
Abstract
Method and apparatus for determining nitrogen oxide content in a high temperature process gas, which involves withdrawing a sample portion of a high temperature gas containing nitrogen oxide from a source to be analyzed. The sample portion is passed through a restrictive flow conduit, which may be a capillary or a restriction orifice. The restrictive flow conduit is heated to a temperature sufficient to maintain the flowing sample portion at an elevated temperature at least as great as the temperature of the high temperature gas source, to thereby provide that deposition of ammonium nitrate within the restrictive flow conduit cannot occur. The sample portion is then drawn into an aspirator device. A heated motive gas is passed to the aspirator device at a temperature at least as great as the temperature of the high temperature gas source. The motive gas is passed through the nozzle of the aspirator device under conditions sufficient to aspirate the heated sample portion through the restrictive flow conduit and produce a mixture of the sample portion in the motive gas at a dilution of the sample portion sufficient to provide that deposition of ammonium nitrate from the mixture cannot occur at reduced temperature. A portion of the cooled dilute mixture is then passed to analytical means capable of detecting nitric oxide.
34 Citations
30 Claims
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1. Fluid sampling apparatus which comprises:
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a. a fluid inlet conduit including means for fluid connection to a source containing fluid to be sampled; b. an aspirator device having a suction inlet opening for the fluid to be sampled, a motive fluid inlet opening, and an exit opening; c. a restrictive flow conduit in fluid communication with said inlet conduit and with the section inlet opening of said aspirator device; d. a motive fluid inlet conduit in fluid communication with the motive fluid inlet opening of said aspirator device, said motive fluid inlet conduit including means for connection to a source of motive fluid for creating a dilute mixture of motive fluid and sample fluid, said motive fluid inlet capable of providing variable dilution ratios of sample fluid to motive fluid; e. first heating means at said restrictive flow conduit for heating a sample of fluid passing therethrough; f. second heating means at said motive fluid inlet conduit for heating motive fluid passing therethrough; g. a discharge conduit in fluid communication with said aspirator device exit opening for discharging the diluted mixture of motive fluid and sample fluid. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. Fluid sampling apparatus, suitable for sampling a high temperature gas for nitrogen oxide measurement, which comprises:
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a. an inlet conduit including means for connection to a high temperature gas source to be sampled; b. an aspirator device having a suction inlet opening, a motive gas inlet opening, and an exit opening for discharging a gas mixture of motive gas and sample gas; c. a restrictive flow conduit in fluid communication with said inlet conduit and with the suction inlet opening of said aspirator device; d. a motive gas inlet conduit in fluid communication with the motive gas inlet opening of said aspirator device, said motive gas inlet conduit including means for connection to a source of motive gas for creating a dilute mixture of motive gas and sample gas, said motive gas inlet capable of providing variable dilution ratios of sample gas to motive gas; e. first heating means at said restrictive flow conduit, said first heating means having the capacity to maintain a gas sample passing through said restrictive flow conduit at a temperature not less than the high temperature of said gas source; f. second heating means at said motive gas inlet conduit for heating motive gas passing therethrough; and g. a discharge conduit in fluid communication with said aspirator device exit opening for discharging the diluted mixture of motive gas and sample gas. - View Dependent Claims (11, 12, 13, 14, 16, 17, 18)
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15. Fluid sampling apparatus according to claim I0 wherein said restrictive flow conduit comprises a capillary.
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19. Method for determining nitrogen oxide content in a high temperature gas, which comprises,
a. withdrawing a sample portion of a high temperature gas containing nitrogen oxide from a high temperature gas source to be analyzed; -
b. passing said sample portion through a restrictive flow conduit; c. heating said restrictive flow conduit to maintain said sample portion flowing therethrough at an elevated temperature at least as great as the temperature of said high temperature gas source to thereby provide that deposition of ammonium nitrate within said restrictive flow conduit cannot occur; d. drawing said sample portion from said restrictive flow conduit into the suction side of an aspirator device; e. passing a flow of motive gas to said aspirator device under conditions sufficient to aspirate said heated sample portion from said restrictive flow conduit and produce a dilute mixture of said sample portion in motive gas; f. passing at least a portion of said dilute mixture at a temperature reduced from said elevated temperature from said aspirator device to analytical means capable of detecting at least nitric oxide; and
,g. adjusting the flow of motive gas to vary the dilution ratio in the dilute mixture and to prevent deposition of ammonium nitrate from said mixture at the reduced temperature. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
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Specification