High reliability flow regulator

Claim 2

A flow regulation system comprising means for passing fluid along a flow path at a substantially constant rate, means to provide a signal indicative of the fluid flow rate along said path, and flow controller means operable in response to said signal to maintain said fluid flow along said path at said substantially constant rate, said flow controller means forming a first portion of said flow path and temperature control means operatively associated with said first portion and responsive to said signal for controlling the temperature and, accordingly, the viscosity and flow rate of said fluid flowing through said first portion, so as to maintain said fluid flow along said flow path at said substantially constant rate.

Claim 3

A flow regulator as in claim 1 wherein, said means forming said first portion of said flow path comprise a flow control resistor.

Claim 4

A flow regulator as in claim 1 wherein, said means to provide a signal indicative of said fluid flow rate comprise means forming a second portion of said flow path, and pressure sensing means operatively associated therewith and operable to sense the pressure drop across said second portion of said flow path portion.

Claim 5

A flow regulator as in claim 3 wherein, said means to provide a signal indicative of said fluid flow rate further comprise, differential pressure-voltage transducer means for providing an output voltage indicative of said pressure drop across said portion of said flow path.

Claim 6

A flow regulator as in claim 4 wherein, said differential pressure-voltage transducer means comprise a pressure sensitive transistor which includes a pressure sensitive diaphragm, and said means to provide said transducer output voltage comprise means to respectively apply the pressures upstream and downstream of said flow path portion to opposite sides of said transistor diaphragm.

Claim 7

A flow regulator as in claim 5 wherein, said pressure application meaNs comprise, a first pressure chamber formed upstream of said flow path portion, a second pressure chamber formed downstream of said flow path portion, a first diaphragm forming one wall of said first chamber with one surface of said first diaphragm being subjected to the pressure in said first pressure chamber, a second diaphragm forming one wall of said second pressure chamber with one surface of the said second diaphragm being subjected to the pressure in said second pressure chamber, means disposing said pressure sensitive transistor intermediate said first and second diaphragms, to isolate the same from said first and second pressure chambers but in such manner that the pressure from said first pressure chamber will be applied to one surface of said transistor diaphragm and the pressure from said second pressure chamber will be applied to the other surface of said transistor diaphragm.

Claim 8

A flow regulator as in claim 4 wherein, said means to provide a signal indicative of said fluid flow rate further comprise, amplifier means, means to provide a reference or set point voltage to said amplifier as one input thereof, means to apply said output voltage from said transducer means as another input to said amplifier means whereby, the output of said amplifier means will be constituted by the amplified voltage difference between said reference voltage and transducer means output voltage, respectively.

Claim 9

A flow regulator as in claim 7 wherein, said flow controller means comprise, means forming another portion of said flow path, temperature control means operatively associated therewith and operable to control the temperature, and accordingly the viscosity and flow rate of said fluid flowing therethrough, and means to apply said amplified voltage difference to said temperature control means to operate the same.

Claim 10

A flow regulator as in claim 8 wherein, said another portion of said flow path is disposed downstream of said portion of said flow path.

Claim 11

A flow regulator as in claim 9 wherein, said another portion of said flow path comprises a flow control resistor.

Claim 12

A flow regulator as in claim 10 wherein, said portion of said flow path comprises a reference resistor.

Claim 13

A flow regulator as in claim 11 wherein, said differential pressure-voltage transducer means comprise a pressure sensitive transistor which includes a pressure sensitive diaphragm, and said means to provide said transducer output voltage comprise means to respectively apply the pressures upstream and downstream of said flow path portion to opposite sides of said transistor diaphragm.

Claim 14

A flow regulator as in claim 12 wherein, said pressure application means comprise, a first pressure chamber formed upstream of said flow path portion, a second pressure chamber formed downstream of said flow path portion, a first diaphragm forming one wall of said first chamber with one surface of said first diaphragm being subjected to the pressure in said first pressure chamber, a second diaphragm forming one wall of said second pressure chamber with one surface of the said second diaphragm being subjected to the pressure in said second pressure chamber, means disposing said pressure sensitive transistor intermediate said first and second diaphragms, to isolate the same from said first and second pressure chambers but in such manner that the pressure from said first pressure chamber will be applied to one surface of said transistor diaphragm and the pressure from said second pressure chamber will be applied to the other surface of said transistor diaphragm.