FLOW SENSOR ASSEMBLY WITH POROUS INSERT

• US 20110226053A1
• Filed: 03/22/2010
• Published: 09/22/2011
• Est. Priority Date: 03/22/2010
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Qasimi, Mohammad Abdul Javvad, Sorenson, Richard C., Speldrich, Jamie
• Granted Patent: US 8,397,586 B2
• Time in Patent Office: Days
• US Class Current: 73/204.23
• CPC Class Codes: B01D 17/10 with stationary filtering elements
• CPC Class Codes: G01F 1/36 the pressure or differential pressure being created by the use of flow constriction
• CPC Class Codes: G01F 1/40 Details of construction of the flow constriction devices
• CPC Class Codes: G01F 1/684 Structural arrangements; Mounting of elements, e.g. in relation to fluid flow
• CPC Class Codes: G01F 1/6842 with means for influencing the fluid flow
• CPC Class Codes: G01F 15/125 Filters

Abstract

The present disclosure relates generally to flow sensors, and more particularly, to methods and devices for reducing variations in fluid flow across the flow sensor for increased accuracy and/or reliability. In one illustrative embodiment, a flow sensor assembly includes a housing with an inlet flow port and an outlet flow port. The housing defines a fluid channel extending between the inlet flow port and the outlet flow port, with a flow sensor positioned in the housing and exposed to the fluid channel. The flow sensor is configured to sense a measure related to the flow rate of a fluid flowing through the fluid channel. A porous insert is situated in the fluid channel, sometimes upstream of the flow sensor. When so configured, and during operation of the flow sensor assembly, a fluid may pass through the inlet flow port, through the porous insert, across the flow sensor, and through the outlet flow port. The porous insert may include pores that are configured to reduce the turbulence in the fluid passing the flow sensor.

Claims

1. A flow sensor assembly, comprising:

a housing including an inlet flow port and an outlet flow port, the housing defining a fluid channel extending between the inlet flow port and the outlet flow port;

a flow sensor positioned in the housing and exposed to the fluid channel, the flow sensor configured to sense a measure related to a flow rate of a fluid flowing through the fluid channel; and

an upstream porous insert situated in the fluid channel of the housing upstream of the flow sensor, wherein the upstream porous insert includes a polymer material, wherein during operation of the flow sensor assembly, a fluid passes through the inlet flow port, through the upstream porous insert, across the flow sensor, and through the outlet flow port, the upstream porous insert configured to enhance a laminar flow profile of the fluid across the flow sensor.

2. The flow sensor assembly of claim 1, wherein the flow sensor includes a heater element, a first sensing element positioned upstream of the heating element, and a second sensing element positioned downstream of the heating element.

3. The flow sensor assembly of claim 1, wherein the flow sensor is a pressure based flow sensor.

4. The flow sensor assembly of claim 1, wherein the upstream porous insert is configured to provide a predetermined pressure drop through the flow channel at a given flow rate.

5. The flow sensor assembly of claim 1 further comprising a downstream porous insert situated in the fluid channel of the housing downstream of the flow sensor, wherein the downstream porous insert includes a polymer material.

6. The flow sensor assembly of claim 5, wherein the upstream porous insert is positioned adjacent the inlet flow port and the downstream porous insert is positioned adjacent the outlet flow port.

7. The flow sensor assembly of claim 1, wherein the upstream porous insert includes a foam.

8. The flow sensor assembly of claim 1, wherein the upstream porous insert includes a woven mesh.

9. The flow sensor assembly of claim 1, wherein the upstream porous insert includes polytetraflouride.

10. A flow sensor assembly, comprising:

a housing including an inlet flow port and an outlet flow port, the housing defining a fluid channel extending between the inlet flow port and the outlet flow port;

a flow sensor situated in the housing and exposed to the fluid channel, the flow sensor configured to sense a measure related to a flow rate of a fluid flowing through the fluid channel;

an upstream porous polymer insert situated in the fluid channel of the housing upstream of the flow sensor;

a downstream porous polymer insert situated in the fluid channel of the housing downstream of the flow sensor; and

wherein during operation of the flow sensor assembly, a fluid passes through the inlet flow port, through the upstream porous polymer insert, across the flow sensor, through the downstream porous polymer insert, and through the outlet flow port, the upstream porous polymer insert including a plurality of pores that are configured to enhance a laminar flow profile of the fluid across the flow sensor.

11. The flow sensor assembly of claim 10, wherein the upstream porous polymer insert and the downstream porous polymer insert cause a predetermined pressure drop across the fluid channel at a given flow rate.

12. The flow sensor assembly of claim 10, wherein upstream porous polymer insert and the downstream porous polymer insert each include a foam.

13. The flow sensor assembly of claim 10, wherein the upstream porous polymer insert and the downstream porous polymer insert include a woven mesh.

14. The flow sensor assembly of claim 10, wherein the upstream porous polymer insert and the downstream porous polymer insert include polytetraflouride.

15. The flow sensor assembly of claim 10, wherein the flow sensor includes a heater element and one or more sensors elements each exposed to the fluid in the fluid channel.

16. The flow sensor assembly of claim 10, wherein the flow sensor is a pressure based flow sensor.

17. A method of reducing variations in a fluid flow through a flow sensor, the method comprising:

providing a flow sensor assembly, the flow sensor assembly including;

a housing including a first flow port and a second flow port, the housing defining a fluid channel extending between the first flow port and the second flow port;

a flow sensor exposed to the fluid channel, the flow sensor configured to detect a measure related a flow rate of a fluid flowing through the fluid channel;

inserting a first polymer insert into the fluid channel upstream of the flow sensor, the first polymer insert including a plurality of pores that are sized to reduce variations in a fluid flow profile across the flow sensor.

18. The method of claim 17, further comprising inserting a second polymer insert into the fluid channel downstream of the flow sensor.

19. The method of claim 18, wherein the first polymer insert and the second polymer insert produce a predetermined pressure drop between the first flow port and the second flow port at a given fluid flow rate.

20. The method of claim 17, wherein the first polymer insert includes a foam.

21. The method of claim 17, wherein the first polymer insert includes a woven mesh.

22. The method of claim 17, wherein the first polymer insert includes polytetraflouride.