Abstract:
A measurement system includes: a pipe insertable into the course of a pipeline; a bluff body arranged in the pipe and configured to generate vortices having a shedding frequency dependent on an instantaneous flow velocity of a fluid such that a Kármán vortex street is formed in the fluid flowing downstream of the bluff body; a vortex sensor arranged downstream of the bluff body, having a resonance frequency and configured to effect mechanical oscillations as to provide a vortex sensor signal including a first component representing oscillations of the vortex sensor with the shedding frequency and a second component representing the mechanical resonance frequency of the vortex sensor; and converter electronics for evaluating the vortex sensor signal and configured to determine whether and/or to what extent the fluid contains foreign substances and/or is a single- or multi-phase substance based on the first and second components of the vortex sensor signal.
Abstract:
A flow measuring device operating on the vortex counter principle, comprises: a measuring tube; a blockage in the form of a bluff body in the measuring tube for bringing about a Karman vortex street with flow dependent vortex frequency; a first pressure fluctuation measuring arrangement for registering vortex related pressure fluctuations and for providing signals dependent on pressure fluctuations; a second pressure fluctuation measuring arrangement for registering vortex related pressure fluctuations and for providing signals dependent on pressure fluctuations. The first pressure fluctuation measuring arrangement is spaced in the longitudinal direction of the measuring tube from the second pressure fluctuation measuring arrangement. An evaluating unit for determining a vortex frequency and a flow measured value dependent thereon, and the evaluation unit is further adapted, based on the ratio of the amplitudes of the signals of the first pressure fluctuation measuring arrangement and the second pressure fluctuation measuring arrangement, or variables derived therefrom, to determine the current Reynolds number and/or the kinematic viscosity of the medium flowing in the measuring tube.
Abstract:
Disclosed is a tube configured to conduct a fluid flowing through the tube in a specified flow direction and for this purpose comprises a tube wall, which encloses a lumen of the tube, and an interference body, which is arranged within the tube but is nevertheless connected to the tube wall at an inner face of the tube wall facing the lumen. In the tube according to the present disclosure, the tube wall has a maximum wall thickness of more than 1 mm and at least two mutually spaced sub-segments with a respective wall thickness that deviates from said maximum wall thickness, wherein the sub-segment is positioned upstream of the interference body in the flow direction, and the sub-segment is positioned downstream of the sub-segment in the flow direction.
Abstract:
A flow measuring device operating on the vortex counter principle, comprises: a measuring tube; a blockage in the form of a bluff body in the measuring tube for bringing about a Karman vortex street with flow dependent vortex frequency; a first pressure fluctuation measuring arrangement for registering vortex related pressure fluctuations and for providing signals dependent on pressure fluctuations; a second pressure fluctuation measuring arrangement for registering vortex related pressure fluctuations and for providing signals dependent on pressure fluctuations. The first pressure fluctuation measuring arrangement is spaced in the longitudinal direction of the measuring tube from the second pressure fluctuation measuring arrangement. An evaluating unit for determining a vortex frequency and a flow measured value dependent thereon, and the evaluation unit is further adapted, based on the ratio of the amplitudes of the signals of the first pressure fluctuation measuring arrangement and the second pressure fluctuation measuring arrangement, or variables derived therefrom, to determine the current Reynolds number and/or the kinematic viscosity of the medium flowing in the measuring tube.
Abstract:
The flow conditioner comprises a diffusor with a guide system arranged within its lumen, a flow rectifier with a disc shaped flow obstruction arranged within its lumen, wherein the flow obstruction has a plurality of flow openings, as well as a confusor, wherein diffusor, flow rectifier and confusor are connected fluidically in series to form a flow path extending from a flow opening of the diffusor to a flow opening of the confusor and involving the lumina of diffusor, flow rectifier and confusor. The guide system of the diffusor includes a sleeve shaped deflection means as well as a plurality of mutually separated connecting elements connected both with the deflection means as well as with the wall of the diffusor. The guide system is so formed and so positioned that the deflection means is spaced from the wall of the diffusor and arranged coaxially with the lumen of the diffusor.
Abstract:
A measurement system includes: a tube; a bluff body, situated in the lumen of the tube, for generating vortices in a flowing fluid such that a Karman vortex street is formed downstream of the bluff body; a vortex sensor, having a mechanical resonant frequency, for providing a vortex sensor signal which changes over time and contains a first component representing the vortex shedding frequency and which contains a second component representing the mechanical resonant frequency of the vortex sensor; and transducer electronics for evaluating the at least one vortex sensor signal and configured to do the following: to determine vortex frequency measurement values representing the shedding frequency using the first component and, if the first component is not present, not to provide flow parameter measurement values and to generate a message indicating the current flow speed is not lower than the current acoustic velocity of the flowing fluid.
Abstract:
A measurement system includes: a tube; a bluff body, situated in the lumen of the tube, for generating vortices in a flowing fluid such that a Kármán vortex street is formed downstream of the bluff body; a vortex sensor, having a mechanical resonant frequency, for providing a vortex sensor signal which changes over time and contains a first component representing the vortex shedding frequency and which contains a second component representing the mechanical resonant frequency of the vortex sensor; and transducer electronics for evaluating the at least one vortex sensor signal and configured to do the following: to determine vortex frequency measurement values representing the shedding frequency using the first component and, if the first component is not present, not to provide such flow parameter measurement values and to generate a message indicating the current flow speed is not lower than the current acoustic velocity of the flowing fluid.
Abstract:
The tube is used to conduct a fluid flowing through the tube in a specified flow direction and for this purpose comprises a tube wall (110), which encloses a lumen (100*) of the tube, and an interference body (120), which is arranged within the tube but is nevertheless connected to the tube wall at an inner face of the tube wall facing the lumen. In the tube according to the invention, the tube wall has a maximum wall thickness (smax) of more than 1 mm and at least two mutually spaced sub-segments (100-1, 100-2) with a respective wall thickness (s110-1, s110-2) that deviates from said maximum wall thickness (smax), wherein the sub-segment (100-1) is positioned upstream of the interference body (120) in the flow direction, and the sub-segment (100-2) is positioned downstream of the sub-segment (100-1) in the flow direction.
Abstract:
A vortex flow measuring device as well as a method for determining by means of a vortex, flow measuring a device, which has a bluff body protruding into the flowing medium and a vortex sensor, the mass flow ratio (x) of an at least at times two- or multiphase medium flowing in a measuring tube and having a gaseous first phase flowing with a first mass flow rate {dot over (m)}G and a liquid second phase flowing with a second mass flow rate {dot over (m)}L. The gaseous phase has a first density (ρG), which differs from a second density (ρL) of the liquid phase, comprising: producing Kármán vortices in the flowing medium at least in the region of the vortex sensor by means of the bluff body, the vortices are shed from the bluff body with a vortex shedding frequency (fv) dependent on an instantaneous flow velocity of the flowing medium; registering by means of the vortex sensor periodic pressure fluctuations caused by the Kármán vortex in the flowing medium for producing a sensor signal corresponding to the pressure fluctuations; selecting from the sensor signal a wanted signal component, which has a frequency band, especially a narrow frequency band, containing the vortex shedding frequency, especially with a relative bandwidth less than 50% of the instantaneous vortex shedding frequency, wherein preferably the instantaneous vortex shedding frequency represents the center frequency of the frequency bandwidth; and applying the wanted signal component (M) for determining a mass flow ratio (x) of the flowing medium, wherein the mass flow ratio (x) is defined as a ratio of the first mass flow {dot over (m)}G to a total mass flow, with which the medium flows, especially according to a formula: x = m . G m . L + m . G .