Flow control system employing a series reference resistor

Claim 2

A flow control system for maintaining a selected constant flow rate from a pressurized storage tank by establishing a constant pressure difference across a reference flow resistor means serially connected in a flow system comprising, a diaphragm repeater means connected in series with said resistor means to one side of said resistor means and establishing a pressure signal proportional to the pressure in the flow system, means connected in series with said resistor means to the opposite side of the resistor means and establishing a pressure signal proportional to the pressure in the flow system, and a pressure responsive means to compare said pressure signals and vary the pressure in said storage tank to maintain a constant flow through said resistor means.

Claim 3

A flow control system for maintaining a selected constant flow rate from a pressurized storage tank, comprising an adjustable pressure source for establishing liquid flow under a preselected pressure range, a reference flow resistor means connected to said source and establishing a pressure drop proportional to flow, a first diaphragm repeater means having a diaphragm sensing chamber connected in series with said resistor means to the upstream side of the resistor and establishing a pressure signal proportional to the upstream pressure, downstream pressure sensing means connected to the downstream side of said resistor means to establish a pressure signal proportional to the downstream pressure, and a pressure responsive means to compare said pressure signals and connected to said source to vary the pressure in the storage tank to maintain a constant flow through said resistor means.

Claim 4

A flow control system for maintaining a selected constant flow rate from a pressurized storage tank, comprising an adjustable pressure source for establishing liquid flow under a preselected pressure range, a reference flow resistor means connected to said source and establishing a pressure drop proportional to flow, a first diaphragm repeater means having a diaphragm sensing chamber connected in series with said resistor means to the upstream side of the resistor and establishing a pressure signal proportional to the upstream pressure, downstream pressure sensing means connected to the downstream side of said resistor means to establish a pressure signal proportional to the downstream pressure, and a pressure responsive means to compare said pressure signals and connected to said source to vary the pressure in the storage tank to maintain a constant flow through said resistor means.

Claim 5

The flow control system of claim 2 wherein said downstream pressure sensing means includes a second diaphragm repeater means having a diaphragm sensing chamber connected in series with said line to the downstream side of the resistor.

Claim 6

The flow control system of claim 2 wherein said pressure responsive means incluDes a diaphragm pressure controller having a controlled chamber connected to said first fluid diaphragm repeater and to said adjustable pressure source and a control chamber connected to said downstream pressure sensing means, said controller having a diaphragm common to both of said chambers and positioned by the force balance on the opposite sides thereof and a set point means coupled to said controller diaphragm to establish an initial bias position of said diaphragm.

Claim 7

The flow control system of claim 4 including a fluid repeater means connected between said controller and said pressure source to provide flow amplification and thereby quick response to a change in the controller''s output pressure.

Claim 8

The flow control system of claim 2 wherein said downstream pressure sensing means includes a second diaphragm repeater means having a diaphragm sensing chamber connected in series with the downstream side of said resistor means to establish a pressure signal proportional to the downstream pressure, and said pressure responsive means includes a diaphragm pressure controller having a controlled chamber coupled to said first diaphragm repeater and to said adjustable pressure source and a control chamber coupled to said second diaphragm repeater, a diaphragm common to both of said chambers with the position of said diaphragm establishing the pressure in said controlled chamber and controlling the source in accordance with said pressure.

Claim 9

The flow control system of claim 6 including a fluid repeater means connected between said adjustable pressure source and said controlled chamber to provide flow amplification and thereby the response to a change in the controller''s output pressure.

Claim 10

A flow control system for establishing and maintaining a preselected constant flow, comprising a storage means, a pressurized fluid source coupled to pressurize said liquid storage means, a flow line means connected to said storage means, a flow reference means serially connected in said flow line means, a first diaphragm repeater having an input chamber serially connected in said flow line means between said pressurized source and said reference means and having a control chamber connected to said source and including a bleed nozzle, said repeater having a diaphragm wall common to said chambers and controlling the flow from said nozzle by the position of said diaphragm wall, a diaphragm pressure controller having a controlled pressure chamber coupled to said control chamber said controlled pressure chamber including a nozzle connected to said source and to said storage means to adjust the pressure in said storage means and the flow in said line, said controller having a control chamber separated from the controlled chamber by a common diaphragm wall overlying said nozzle, a resilient means connected to said common diaphragm wall and urging the wall to close said nozzle, and pressure sensing means connected in said flow line means downstream of said flow reference means, and coupled to said control chamber.

Claim 11

A flow control system for establishing and maintaining a preselected constant flow, comprising a storage means, a pressurized fluid source coupled to pressurize said liquid storage means, a flow line means connected to said storage means, a flow reference means serially connected in said flow line means, a first diaphragm repeater having an input chamber serially connected in said flow line means between said pressurized source and said reference means and having a control chamber connected to said source and including a bleed nozzle, said repeater having a diaphragm wall common to said chambers and controlling the flow from said nozzle by the position of said diaphragm wall, a diaphragm pressure controller having a controlled pressure chamber coupled to said control chamber said controlled pressure chamber including a nozzle connected to said source and to said storage means to adjust the pressure in said storage means and the flow in said line, said controller having a control chamber separated from the controlled chamber by a common diaphragm wall overlying said nozzle, a resilient means connected to said common diaphragm wall and urging the wall to close said nozzle, and pressure sensing means connected in said flow line means downstream of said flow reference means, and coupled to said control chamber.

Claim 12

The flow control system of claim 8 wherein said pressure sensing means is a second diaphragm repeater having an input chamber serially connected in said flow line means downstream of said reference means and having a control chamber including a nozzle connected to said source, said second repeater having a diaphragm wall common to said chambers and overlying said corresponding nozzle to control, by the position of said wall, the flow through said nozzle, said control chamber being connected to said control chamber of said pressure controller.

Claim 13

The flow control system of claim 8 having an output repeater with a control chamber connected to the nozzle of said controller and an output chamber connected to said source and to said storage means, a diaphragm common to said chambers, and a bleed nozzle in said output chamber.

Claim 14

The flow control system of claim 8 wherein said flow reference means is a resistor, said pressure sensing means is a second diaphragm repeater haviNg an input chamber serially connected in said flow line means downstream of said reference means and having a control chamber connected to fluid source, said repeater having a diaphragm wall common to said chambers and a bleed nozzle in said control chamber with the nozzle opening controlled by the position of said wall, an output diaphragm repeater having a control chamber connected to said storage means and said fluid source, a bleed nozzle in said control chamber, said output repeater having a diaphragm overlying said nozzle and a control connected to the nozzle of said pressure controller.