Pulsed eddy flow meter

• US 4,627,294 A
• Filed: 08/12/1985
• Issued: 12/09/1986
• Est. Priority Date: 08/12/1985
• Status: Expired due to Fees

• Current Assignee: Hyok S. Lew
• Original Assignee: Hyok S. Lew
• Inventors: Lew, Hyok S.
• Primary Examiner(s): Goldstein, Herbert
• Application Number:
  US06/764,890
• Time in Patent Office: 484 Days
• Field of Search: 73/861.05, 73/861.21, 73/861.22, 73/861.24
• US Class Current: 73/861.05
• CPC Class Codes: G01F 1/32 using swirl flowmeters
• CPC Class Codes: G01F 1/708 Measuring the time taken to traverse a fixed distance

Abstract

A flow meter comprising a pulsed eddy generator disposed at an upstream section in the flow passage and an eddy sensor disposed at a downstream section, wherein the pulsed eddy generator is programmed to be activated automatically following a predetermined brief period of deactivation, which brief period of deactivation starts at the moment the eddy generator is switched from an activation mode to a deactivation mode by the eddy sensor that senses the leading edge of the eddy stream generated by the eddy generator during a preceding activation. As a consequence, the eddy generator generates a series of pulsed eddy streams created during the activation of the eddy generator, wherein each of which pulsed eddy streams is interceded by silent streams created during the deactivation period of the eddy generator. The representative fluid velocity is obtained by dividing the distance between the eddy generator and the eddy sensor by the duration of each activated period of the eddy generator, which duration is equal to the period of one complete cycle of the pulsed flow minus the predetermined duration of the deactivated period of the eddy generator. The actual flow rate is obtained by calibrating and/or statistically analyzing the representative velocity, which may be carried out by a microcomputer or microprocessor.

Claims

1. A pulsed eddy flow meter comprising in combination:

(a) a flow passage;

(b) an eddy generating means disposed within said flow passage at one section of said flow passage wherein the generation of eddies in fluid medium flowing across said one section of said flow passage is enhanced when said eddy generating means is in an activated state and the generation of eddies in fluid medium flowing across said one section of said flow passage is suppressed when said eddy generating means is in a deactivated state;

(c) an eddy sensing means disposed within said flow passage at another section of said flow passage downstream from said one section;

(d) a transducer converting mechanical effect of eddies on said eddy sensing means to an electric signal;

(e) a controller receiving said electrical signal from said transducer, said controller imposing one state out of said activated state and said deactivated state on said eddy generating means wherein said controller automatically imposes said activated state following a deactivated state of a predetermined duration and imposes said deactivated state at an instant when said eddy sensing means detects an eddy of an intensity greater than a thresh-hold intensity, which thresh-hold intensity is greater than the intensity of eddies generated by said eddy generating means at said deactivated state and is less that the intensity of eddies generated by said eddy generating means at said activated state; and

(f) means for obtaining a representative fluid velocity by dividing the distance between said eddy generating means and said eddy sensing means by the duration of the imposition of the most recent activated state.

2. The combination as set forth in claim 1 wherein said combination includes means for calibrating said representative fluid velocity to flow rate data of the fluid flowing through said flow passage.

3. The combination as set forth in claim 2 wherein said predetermined duration of deactivated state preceding said automatic imposition of said activated state is adjustable.

4. The combination as set forth in claim 3 wherein said thresh-hold intensity is adjustable.

5. The combination as set forth in claim 2 wherein said thresh-hold intensity is adjustable.

6. The combination as set forth in claim 2 wherein said combination includes means for displaying said flow rate data.

7. The combination as set forth in claim 2 wherein said combination includes means for transmitting said flow rate data usable as an input signal to a flow control device.

8. A pulsed eddy flow meter comprising in combination:

(a) a flow passage;

(b) an eddy generating means disposed within said flow passage at one section of said flow passage wherein the generation of eddies in fluid medium flowing across said one section of said flow passage is enhanced when said eddy generating means is in an activated state and the generation of eddies in fluid medium flowing across said one section of said flow passage is suppressed when said eddy generating means is in a deactivated state;

(c) an eddy sensing means disposed within said flow passage at another section of said flow passage downstream from said one section;

(d) a controller imposing said activated state of a finite duration and said deactivated state of another finite duration on said eddy generating means in an alternating fashion

(e) means for measuring the time interval between the onset of each said activated state of a finite duration and the onset of the sensing of eddies generated by said eddy generating means during said each said activated state of a finite duration; and

(f) means for obtaining a representative fluid velocity by dividing the distance between said eddy generating means and said eddy sensing means by said time interval between the onset of each said activated state of a finite duration and the onset of the sensing of eddies generated by said eddy generating means during said each said activated state of a finite duration.

9. The combination as set forth in claim 8 wherein said combination includes means for calibrating said representative fluid velocity to flow rate data of the fluid flowing through said flow passage.

10. The combination as set forth in claim 9 wherein predetermined duration of said deactivated state of another finite duration is adjustable.

11. The combination as set forth in claim 10 wherein predetermined duration of said activated state of a finite duration is adjustable.

12. The combination as set forth in claim 9 wherein predetermined duration of said activated state of a finite duration is adjustable.

13. The combination as set forth in claim 9 wherein said combination includes means for displaying said flow rate data.

14. The combination as set forth in claim 9 wherein said combination includes means for transmitting said flow rate data usable as an input signal to a flow control device.