Measuring system with a flow conditioner arranged at an inlet of a measuring table

• US 7,878,073 B2
• Filed: 09/24/2009
• Issued: 02/01/2011
• Est. Priority Date: 07/21/2006
• Status: Active Grant

• Current Assignee: Endress+Hauser Flowtec AG (Endress+Hauser AG)
• Original Assignee: Endress+Hauser Flowtec AG (Endress+Hauser AG)
• Inventors: Hoecker, Rainer
• Primary Examiner(s): PATEL, HARSHAD R
• Application Number:
  US12/585,772
• Publication Number:
  US 20100043566A1
• Time in Patent Office: 495 Days
• Field of Search: None
• US Class Current: 73/861.22
• CPC Class Codes: G01F 1/3209 using Karman vortices
• CPC Class Codes: G01F 1/86 Indirect mass flowmeters, e.g. measuring volume flow and density, temperature or pressure
• CPC Class Codes: G01F 1/88 with differential-pressure measurement to determine the volume flow
• CPC Class Codes: G01F 15/00 Details of, or accessories for, apparatus of groups G01F1/00 - G01F13/00 insofar as such details or appliances are not adapted to particular types of such apparatus
• CPC Class Codes: G01F 15/185 Connecting means, e.g. bypass conduits

Abstract

The measuring system is inserted into the course of a process line and serves for registering at least one measured variable of a medium flowing in the process line. The measuring system includes for such purpose a measuring transducer having a measuring tube serving for conveying medium being measured and a sensor arrangement, which has at least one sensor element reacting primarily to the measured variable to be registered, and which delivers by means of at least one sensor element at least one measurement signal influenced by the measured variable. Further, the measuring system includes a measuring electronics communicating with the measuring transducer and using the at least one measurement signal for producing, at least at times, at least one measured value instantaneously representing the measured variable. The measuring tube has, in the case of the measuring system of the invention, a smaller flow cross section than a supply segment of the process line connected to the inlet end of the measuring system. To this end, the measuring system further includes a flow conditioner arranged at the inlet end of the measuring tube and mediating between the measuring tube and the supply segment of the process line. The flow conditioner has a lumen tapering in the direction of the measuring tube. During operation, medium flows through the lumen of the flow conditioner. The flow conditioner includes at least one impingement surface arranged upstream of its outlet end and protruding into the lumen of the flow conditioner. During operation, medium conveyed in the flow conditioner flows against the impingement surface.

Claims

1. Method for registering at least one measured variable of a medium flowing in a process line, by means of a measuring system at least partially inserted into the course of the process line said measuring system including a flow conditioner connected to a supply segment of the process line, as well as a measuring transducer connected to the flow conditioner, said method comprising:

allowing the medium to be measured to flow out of the supply segment into the flow conditioner;

inducing at least one essentially stationary toroidal vortex within the medium flowing in an inlet region of the flow conditioner in a manner such that a principal axis of greatest inertia of the at least one toroidal vortex essentially coincides with the longitudinal axis of the flow conditioner, and/or with a longitudinal axis of the measuring tube;

allowing the medium to be measured to flow out of the flow conditioner into a measuring tube of the connected measuring transducer;

as well as

producing at least one measurement signal, influenced by the measured variable to be registered, by application of at least one sensor element reacting primarily to the measured variable and/or to changes in the measured variable.

2. The method as claimed in claim 1, further comprising:

inducing at least one further, essentially stationary toroidal vortex in the inlet region of the flow conditioner in such a manner that a principal axis of greatest inertia of each of the at least two toroidal vortices essentially aligns with the other;

accelerating medium flowing in the flow conditioner in the direction of a longitudinal axis of the flow conditioner;

allowing medium to flow against an impingement surface of the flow conditioner opposing flowing medium in a boundary region of the flow conditioner for inducing essentially stationary, toroidal vortices in the inlet region of the flow conditioner; and

allowing medium to flow past a circumferential inner edge protruding into a lumen of the flow conditioner.

3. The method as claimed in claim 2, further comprising:

allowing medium to flow against an impingement surface of the flow conditioner opposing flowing medium in a boundary region circumferentially closed along a directrix of the flow conditioner for inducing essentially stationary, toroidal vortices in the inlet region of the flow conditioner;

wherein the impingement surface of the flow conditioner opposes flowing medium in said boundary region circumferentially closed along the directrix of the flow conditioner.

4. The method as claimed in claim 1, further comprising at least one of the following steps:

inducing at least one further, essentially locationally fixed toroidal vortex in the inlet region of the flow conditioner in such a manner that a principal axis of greatest inertia of each of the at least two toroidal vortices essentially aligns with the other;

allowing medium to flow against an impingement surface of the flow conditioner opposing flowing medium in a boundary region circumferentially closed along a directrix of the flow conditioner.

5. The method as claimed in claim 4, further comprising:

allowing medium to flow past a circumferential inner edge protruding into a lumen of the flow conditioner.

6. The method as claimed in claim 1, further comprising:

inducing at least one further, essentially stationary toroidal vortex in the inlet region of the flow conditioner in such a manner that a principal axis of greatest inertia of each of the at least two toroidal vortices essentially aligns with the other, wherein said step of inducing the at least further one, essentially stationary, toroidal vortex in the inlet region of the flow conditioner includes steps of allowing medium to flow past a circumferential inner edge protruding into a lumen of the flow conditioner.

7. The method as claimed in claim 1, wherein the inner edge protruding into a lumen of the flow conditioner is circumferentially closed along a directrix of the flow conditioner;

and/or

wherein the at least one further, essentially stationary toroidal vortex is essentially locationally fixed in the inlet region of the flow conditioner.

8. The method as claimed in claim 1, wherein at least one essentially stationary toroidal vortex induced within medium flowing in the inlet region of the flow conditioner is essentially locationally fixed within said inlet region of the flow conditioner;

and/or

wherein the at least one measured variable is selected from a group consisting of a mass flow of said medium, a volume flow of said medium, a flow velocity of said medium, a density of said medium, a viscosity, of said medium, a pressure of said medium, and a temperature of said medium.

9. The method as claimed in claim 1, further comprising:

partially blocking medium flowing into the flow conditioner for inducing said at least one toroidal vortex.

10. The method as claimed in the claim 9, wherein the step of partially blocking medium flowing into the flow conditioner further includes a step of allowing medium to flow against an impingement surface of the flow conditioner opposing the flowing medium in a border region of the flow conditioner.

11. The method as claimed in claim 9, wherein the step of partially blocking medium flowing into the flow conditioner further includes a step of allowing medium to flow against an impingement surface of the flow conditioner opposing flowing medium in a boundary region circumferentially closed along a directrix of the flow conditioner for inducing essentially stationary, toroidal vortices ,in the inlet region of the flow conditioner;

and wherein the impingement surface of the flow conditioner opposes flowing medium in said boundary region circumferentially closed along the directrix of the flow conditioner.