Thermal, flow measuring device

Patent metadata

Field	Value
Publication number	US-9696191-B2
Application number	US-201314436156-A
Country	US
Kind code	B2
Filing date	Sep 23, 2013
Priority date	Oct 19, 2012
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

Abstract

A thermal, flow measuring device for determining and/or monitoring a mass flow of a measured medium through a measuring tube, comprising a sensor having a first heatable resistance thermometer and at least a second heatable resistance thermometer, wherein the sensor has a longitudinal axis and an end face, which is divided into at least two adjoining segments, wherein a surface normal vector of at least a first segment forms with the longitudinal axis of the sensor an angle of at least 5°; and use of a thermal, flow measuring device.

First claim

The invention claimed is:

1. A thermal, flow measuring device for determining and/or monitoring a mass flow of a measured medium through a measuring tube, comprising:
a sensor with at least first and second temperature sensor elements, which contain thin-film resistance thermometers, wherein:
one of said temperature sensor elements is heatable, said sensor has a longitudinal axis and an end face, which is divided into at least two adjoining segments;
a surface normal vector of at least a first segment forms with the longitudinal axis of said sensor an angle of at least 5°;
the end face is divided into at least three segments, an upstream, first side segment, a middle segment and a downstream, second side segment;
the first segment is the upstream, first side segment; and
the upstream, first side segment has a greater area than the downstream, second side segment.

2. The thermal, flow measuring device as claimed in claim 1 , wherein:
the surface normal vector of the inclined surface of said first segment forms with the longitudinal axis an angle of at least 8°, especially preferably between 10-35°.

3. The thermal, flow measuring device as claimed in claim 1 , wherein:
between said upstream, first side segment and said middle segment a first intersection edge is defined;
between said downstream, second side segment and said middle segment a second intersection edge is defined; and
the separation between the flow direction opposed peripheral point of said upstream, first side segment and said first intersection edge equals the separation between the flow direction, peripheral point of said downstream, second side segment and said second intersection edge.

4. The thermal, flow measuring device as claimed in claim 1 , wherein:
said sensor has an end face of sheet metal arranged between the measured medium and said temperature sensor elements; and
said sheet metal is between 0.5 to 0.7 mm thick.

5. The thermal, flow measuring device as claimed in claim 1 , wherein:
perpendicular to the flow direction of the medium at said middle segment on each side of said middle segment, a support segment stabilizes said middle segment.

6. The thermal, flow measuring device as claimed in claim 5 , wherein:
said stabilizing support segment slopes from the plane of said middle segment at an angle between 10-80°, especially preferably at an angle from 50-70°.

7. The thermal, flow measuring device as a claimed in claim 1 , wherein:
said first temperature sensor element is embodied as a plate shaped, thin layer element.

8. The thermal, flow measuring device as claimed in claim 1 , wherein:
said first temperature sensor element is oriented essentially parallel to the area of said first segment.

9. The thermal, flow measuring device as claimed in claim 1 , wherein:
said middle segment has an area with a surface normal vector, which extends along the longitudinal axis.

10. The thermal, flow measuring device as claimed in claim 4 , wherein:
said first segment forms at least 5%, preferably at least 15%, especially 20-40%, of said end face.

11. The thermal, flow measuring device as claimed in claim 1 , wherein:
said first segment is designed for forming a thermal boundary layer of increased boundary layer thickness.

12. The thermal, flow measuring device as claimed in claim 1 , wherein:
said first segment is designed for forming a recirculation in a flowing medium.

13. The thermal, flow measuring device as claimed in claim 1 , wherein:
said first and second temperature sensor elements are heatable and each has two operating states, in a first operating state said temperature sensor element is kept at a constant temperature and in a second operating state said temperature sensor ascertains the temperature of the medium;
said first temperature sensor element is located in said first operating state when said second temperature sensor element is located in said second operating state;
said first temperature sensor element is located in said second operating state when said second temperature sensor element is located in said first operating state; and
the thermal, flow measuring device has a circuit for switching said first and said second temperature sensor elements between said first and said second operating states.

14. The thermal, flow measuring device as claimed in claim 1 , wherein:
said sensor has a sensor body and a sensor cap; and
a terminal end face is located on said sensor cap.

15. The use of a thermal, flow measuring device as claimed in claim 1 , for determining and/or monitoring mass flow of a liquid flowing through a measuring tube.

Assignees

• Endress & Hauser Flowtec Ag

Inventors

• Pfau Axel
• Papathanasiou Panagiotis
• Gaberthuel Stephan
• Baur Tobias
• Schultheis Hanno

Classifications

• G01P5/12

  using variation of resistance of a heated conductor · CPC title

• G01F1/6842

  with means for influencing the fluid flow · CPC title

• G01F1/684

  Structural arrangements; Mounting of elements, e.g. in relation to fluid flow · CPC title

• G01F1/69 Primary

  of resistive type · CPC title