US 12,215,990 B2
Method and device for measuring a flow velocity of a gas stream
Hans-Georg Conrads, Hannover (DE)
Assigned to PROMECON PROCESS MEASUREMENT CONTROL GMBH, Barleben (DE)
Filed by PROMECON PROCESS MEASUREMENT CONTROL GMBH, Barleben (DE)
Filed on Feb. 8, 2024, as Appl. No. 18/436,714.
Application 18/436,714 is a continuation of application No. 17/278,937, granted, now 11,953,358, previously published as PCT/EP2019/075710, filed on Sep. 24, 2019.
Claims priority of application No. 10 2018 123 448.1 (DE), filed on Sep. 24, 2018.
Prior Publication US 2024/0255333 A1, Aug. 1, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. G01F 1/704 (2006.01); G01F 1/7086 (2022.01); G01F 1/712 (2006.01)
CPC G01F 1/7086 (2013.01) [G01F 1/7044 (2013.01); G01F 1/712 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A method for measuring a flow velocity of a gas stream featuring the steps:
(a) time-resolved measurement of an IR radiation parameter of IR radiation of the gas stream at a first measurement point outside of the gas stream, thereby obtaining a first IR radiation parameter curve,
(b) time-resolved measurement of an IR radiation parameter at a second measurement point outside of the gas stream, thereby obtaining a second IR radiation parameter curve,
(c) calculation of a transit time from the first IR radiation parameter curve and the second IR radiation parameter curve, and
(d) calculation of the flow velocity from the transit time,
(e) wherein the gas stream is a stream of a gas mixture that contains a first gas and at least a second gas,
(f) wherein a temperature of the gas stream is at least 1000° C.,
(g) wherein gas stream flows in a pipe and contains particles, the walls of the pipe and the particles emitting black body radiation that is measured by means of a photo detector,
(h) the IR radiation parameter is measured photoelectrically by means of the photo detector in a wavelength interval between 1.5 μm and 15 μm and at a measurement frequency is at least 1 kilohertz,
(i) the IR radiation parameter is the irradiance of the infrared radiation caused by the IR radiation emitted by the gas stream due to the temperature of the gas stream.