Magnetic flow sensor
OwnerMurray F. Fellerinventor
Life of this patent
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Abstract
Sensors for measuring the flow rate of fluids flowing through a chamber. The chamber is formed using electrically insulating material through which there is an orthogonal alternating magnetic field provided by a mechanically repositioned permanent magnet and at least a pair of electrodes in line with and orthogonal to the magnetic field. This provides an electrical potential with a magnitude proportional to flow rate. The alternating magnetic field may also be provided by a stationary multiple electromagnet. Various embodiments are disclosed which make use of electromagnetics, stepper motors and other modifications for adapting the flow sensor to a wide variety of applications and environmental conditions.
Claims13
A flow sensor for measuring a rate of flow of an electrically conductive liquid, the sensor comprising:
- an electrically insulated flow passage;
- a permanent magnet providing magnetic flux orthogonal to the liquid flow;
- a pair of electrodes disposed opposite the passage and contacting the liquid, the electrodes being in line with and orthogonal to the flow passage and generally parallel to the magnetic flux, such that said flow passage forms a generally linear fluid flow path;
- and
- a mechanical drive for periodically repositioning the magnet to alternate the magnetic flux polarity to produce an alternating voltage at the electrodes having a magnitude proportional to a flow rate of the liquid.
A flow sensor for measuring a flow rate of an electrically conductive liquid, the sensor comprising:
- an electrically insulated flow passage;
- an electromagnet having a plurality of adjacent poles of opposite polarity and positioned orthogonally with respect to the flow passage;
- and
- a pair of electrodes located on opposite sides of the flow passage and positioned in line with and orthogonal to the magnetic flux such that the flow passage forms a generally linear fluid flow path, the electrodes producing an alternating voltage with a magnitude proportional to a flow rate of the liquid.
A flow sensor for measuring the flow rate of an electrically conductive liquid, comprising:
- a plurality of electrically insulated adjacent flow passages;
- an electromagnet having a plurality of adjacent poles of opposite polarity and providing substantially the same polarity and magnetic flux orthogonal to the liquid flow in both passages;
- three electrodes in contact with the liquid, first and second ones of the electrodes being located on the outsides of the flow passages in line with and orthogonal to said magnetic flux, the third electrode being common to the flow passages to effect an addition of voltages from the first and second electrodes which alternate at the frequency of the electromagnetic electrical excitation and with a magnitude proportional to the flow rate of said liquid.
Dependencies are inferred from the claim text.