Continuous control for introducing material into a flowing liquid

Claim 2

An additive metering system for supplying relatively minute quantities of a fluid material to a flowing liquid, comprising a means connected to meter said liquid and establishing a flow related signal, a linear metering valve coupling said fluid material to said flowing liquid, a servopositioning means coupled to said metering valve, a feedback signal means coupled to said positioning means, a comparator means having input means connected to said meter means and said feedback signal means and to a preset signal means and establishing a drive signal proportional to said flow related signal and said feedback signal, means connecting said comparator means to energize said positioning means in accordance with the drive signal to accurately position said linear metering valve in accordance with said drive signal, said and flow line being at a selected nominal pressure and including a pressure compensating signal means connected to said comparator means for compensating the preset signal of said preset signal means in accordance with the actual pressure in said flow line.

Claim 3

An additive metering system for supplying relative small quantities of an additive liquid to a flowing liquid, comprising a flow line, a signal means connected in said flow line to establish a flow related signal, a pressurized fluid additive liquid supply connected to said flow line, metering valve in said supply and having an opening control element to vary the valve opening, the flow through said valve opening varying linearly with the size of said valve opening, a servomotor coupled to said control element, a feedback signal means actuated by said servomotor, a comparator means having a preset signal means and connected to said meter means and said feedback signal means and establishing a drive signal proportional to the comparison of said preset signal, and said flow related signal and said feedback signal, means connecting said servomotor to said comparator means to energize said motor in accordance with said drive signal to accurately position said metering valve in accordance with said drive signal, and a pressure compensating signal means establishing a signal related to the pressure in said flow line and means connecting said pressure compensating signal means to said comparator means to modify said drive signal in accordance with that pressure in said flow line.

Claim 4

An additive metering system for supplying relative small quantities of an additive liquid to a flowing liquid, comprising a flow line, a signal means connected in said flow line to establish a flow related signal, a pressurized fluid additive liquid supply connected to said flow line, metering valve in said supply and having an opening control element to vary the valve opening, the flow through said valve opening varying linearly with the size of said valve opening, a servomotor coupled to said control element, a feedback signal means actuated by said servomotor, a comparator means having a preset signal means and connected to said meter means and said feedback signal means and establishing a drive signal proportional to the comparison of said preset signal, and said flow related signal and said feedback signal, means connecting said servomotor to said comparator means to energize said motor in accordance with said drive signal to accurately position said metering valve in accordance with said drive signal, and a pressure compensating signal means establishing a signal related to the pressure in said flow line and means connecting said pressure compensating signal means to said comparator means to modify said drive signal in accordance with that pressure in said flow line.

Claim 5

An additive metering system for supply relative small quantities of an additive liquid to a flowing liquid, comprising a flow line, a signal means connected in said flow line to establish a flow related signal, a pressurized fluid additive liquid supply connected to said flow line, metering valve in said supply and having an opening control element to vary the valve openIng, the flow through said valve opening varying linearly with the size of said valve opening, a servomotor coupled to said control element, a feedback signal means actuated by said servomotor, a comparator means having a preset signal means and connected to said meter means and said feedback signal means and establishing a drive signal proportional to the comparison of said preset signal, and said flow related signal and said feedback signal, means connecting said servomotor to said comparator means to energize said motor in accordance with said drive signal to accurately position said metering valve in accordance with said drive signal, and a cutoff valve connected in said additive material supply and means connecting said cutoff valve to said comparator means and responsive to a selected minimum related signal to cut off said additive flow.

Claim 6

An additive metering system for supply relative small quantities of an additive liquid to a flowing liquid, comprising a flow line, a signal means connected in said flow line to establish a flow related signal, a pressurized fluid additive liquid supply connected to said flow line, metering valve in said supply and having an opening control element to vary the valve openIng, the flow through said valve opening varying linearly with the size of said valve opening, a servomotor coupled to said control element, a feedback signal means actuated by said servomotor, a comparator means having a preset signal means and connected to said meter means and said feedback signal means and establishing a drive signal proportional to the comparison of said preset signal, and said flow related signal and said feedback signal, means connecting said servomotor to said comparator means to energize said motor in accordance with said drive signal to accurately position said metering valve in accordance with said drive signal, and a cutoff valve connected in said additive material supply and means connecting said cutoff valve to said comparator means and responsive to a selected minimum related signal to cut off said additive flow.

Claim 7

An additive metering system for supply relative small quantities of an additive liquid to a flowing liquid, comprising a flow line, a signal means connected in said flow line to establish a flow related signal, a pressurized fluid additive liquid supply connected to said flow line, metering valve in said supply and having an opening control element to vary the valve opening, the flow through said valve opening varying linearly with the size of said valve opening, a servomotor coupled to said control element, a feedback signal means actuated by said servomotor, a comparator means having a preset signal means and connected to said meter means and said feedback signal means and establishing a drive signal proportional to the comparison of said preset signal, and said flow related signal and said feedback signal, means connecting said servomotor to said comparator means to energize said motor in accordance with said drive signal to accurately position said metering valve in accordance with said drive signal, and said metering valve being a micrometer valve including a circular valve opening and a tapered shaft axially movable through said opening, said valve including a rotatable positioning shaft and a spring coupling said tapered shaft to said positioning shaft to axially position said tapered shaft in response to rotation of said positioning shaft, an axially adjustable coupling interconnecting said positioning shaft and said motor shaft to permit axial adjustment of said positioning shaft relative to said motor shaft.

Claim 8

An additive metering system for supply relative small quantities of an additive liquid to a flowing liquid, comprising a flow line, a signal means connected in said flow line to establish a flow related signal, a pressurized fluid additive liquid supply connected to said flow line, metering valve in said supply and having an opening control element to vary the valve opening, the flow through said valve opening varying linearly with the size of said valve opening, a servomotor coupled to said control element, a feedback signal means actuated by said servomotor, a comparator means having a preset signal means and connected to said meter means and said feedback signal means and establishing a drive signal proportional to the comparison of said preset signal, and said flow related signal and said feedback signal, means connecting said servomotor to said comparator means to energize said motor in accordance with said drive signal to accurately position said metering valve in accordance with said drive signal, and said metering valve being a micrometer valve including a circular valve opening and a tapered shaft axially movable through said opening, said valve including a rotatable positioning shaft and a spring coupling said tapered shaft to said positioning shaft to axially position said tapered shaft in response to rotation of said positioning shaft, an axially adjustable coupling interconnecting said positioning shaft and said motor shaft to permit axial adjustment of said positioning shaft relative to said motor shaft.

Claim 9

An additive metering system for supplying relative small quantities of an additive liquid to a flowing liquid, comprising a flow line, a signal means connected in said flow line to establish a flow related signal, a pressurized fluid additive liquid supply connected to said flow line, metering valve in said supply and having an opening control element to vary the valve opening, the flow through said valve opening varying linearly with the size of said valve opening, a servomotor coupled to said control element, a feedback signal means actuated by said servomotor, a comparator means having a preset signal means and connected to said meter means and said feedback signal means and establishing a drive signal proportional to the comparison of said preset signal, and said flow related signal and said feedback signal, means connecting said servomotor to said comparator means to energize said motor in accordance with said drive signal to accurately position said metering valve in accordance with said drive signal, and said signal means generates a train of signal pulses having a repetition rate proportional to the flow, said comparator includes means establishing a direct current analog signal proportional to said repetition rate, and said feedback signal means establishes a corresponding direct current analog signal, said drive signal being a direct current signal having a polarity related to the relative amplitudes of said analog signals to correspondingly energize said servomotor to open and close said metering valves.

Claim 10

An additive metering system for supplying relative small quantities of an additive liquid to a flowing liquid, comprising a flow line, a signal means connected in said flow line to establish a flow related signal, a pressurized fluid additive liquid supply connected to said flow line, metering valve in said supply and having an opening control element to vary the valve opening, the flow through said valve opening varying linearly with the size of said valve opening, a servomotor coupled to said control element, a feedback signal means actuated by said servomotor, a comparator means having a preset signal means and connected to said meter means and said feedback signal means and establishing a drive signal proportional to the comparison of said preset signal, and said flow related signal and said feedback signal, means connecting said servomotor to said comparator means to energize said motor in accordance with said drive signal to accurately position said metering valve in accordance with said drive signal, and said signal means generates a train of signal pulses having a repetition rate proportional to the flow, said comparator includes means establishing a direct current analog signal proportional to said repetition rate, and said feedback signal means establishes a corresponding direct current analog signal, said drive signal being a direct current signal having a polarity related to the relative amplitudes of said analog signals to correspondingly energize said servomotor to open and close said metering valves.

Claim 11

An additive metering system for supplying relatively minute quantities of a fluid material to a fLowing liquid, comprising a means connected to meter said liquid and establishing a flow related signal, a linear metering valve coupling said fluid material to said flowing liquid, a servo-positioning means coupled to said metering valve, a feedback signal means coupled to said positioning means, a comparator means having input means connected to said meter means and said feedback signal means and to a preset signal means and establishing a drive signal proportional to said flow related signal and said feedback signal, means connecting said comparator means to energize said positioning means in accordance with the drive signal to accurately position said linear metering valve in accordance with said drive signal, and said fluid additive liquid is held in a pressurized tank under a preselected constant pressure, said signal means includes a pulse means forming a pulse train having a repetition rate corresponding to the flow rate, said metering valve includes a tapered control shaft axially movable into the valve opening said servomotor includes a rotatable motor shaft, an axially adjustable coupling connecting said control shaft to said motor shaft to permit independent axial movement therebetween, said comparator means including means to convert said pulse train to an analog signal, said feedback signal means including a potentiometer connected to said servomotor to establish a signal corresponding to the position of said control shaft.

Claim 12

An additive metering system for supplying relatively minute quantities of a fluid material to a fLowing liquid, comprising a means connected to meter said liquid and establishing a flow related signal, a linear metering valve coupling said fluid material to said flowing liquid, a servo-positioning means coupled to said metering valve, a feedback signal means coupled to said positioning means, a comparator means having input means connected to said meter means and said feedback signal means and to a preset signal means and establishing a drive signal proportional to said flow related signal and said feedback signal, means connecting said comparator means to energize said positioning means in accordance with the drive signal to accurately position said linear metering valve in accordance with said drive signal, and said fluid additive liquid is held in a pressurized tank under a preselected constant pressure, said signal means includes a pulse means forming a pulse train having a repetition rate corresponding to the flow rate, said metering valve includes a tapered control shaft axially movable into the valve opening said servomotor includes a rotatable motor shaft, an axially adjustable coupling connecting said control shaft to said motor shaft to permit independent axial movement therebetween, said comparator means including means to convert said pulse train to an analog signal, said feedback signal means including a potentiometer connected to said servomotor to establish a signal corresponding to the position of said control shaft.

Claim 13

The additive metering system of claim 6 including a pressure compensating signal means to establish compensating signals in accordance with the line pressure, and means connecting said pressure compensating signal means to said comparator means to modify said drive signal in accordance with said line pressure.

Claim 14

The additive system of claim 6 including a cutoff valve connected in said additive line, and means connecting said cutoff valve to said comparator means and responsive to a selected flow related signal to cut off flow in said additive flow line.

Claim 15

An additive metering system for supplying relatively minute quantities of a fluid material to a flowing liquid, comprising a means connected to meter said liquid and establishing a flow related signal, a linear metering valve coupling said fluid material to said flowing liquid, a servo-positioning means coupled to said metering valve, a feedback signal means coupled to said positioning means, a comparator means having input means connected to said meter means and said feedback signal means and to a preset signal means and establishing a drive signal proportional to said flow related signal and said feedback signal, means connecting said comparator means to energize said positioning means in accordance with the drive signal to accurately position said linear metering valve in accordance with said drive signal, and said fluid material is an additive liquid, and having a tank containing said additive liquid, a gas pressure line connected to said tank, a housing enclosing said means to meter the flowing liquid, said metering valve, said feedback signal means, said servo-positioning means and said comparator means, means releasably securing said tank to the housing, and conduit means connecting said tank to said metering valve.

Claim 16

An additive metering system for supplying relatively minute quantities of a fluid material to a flowing liquid, comprising a means connected to meter said liquid and establishing a flow related signal, a linear metering valve coupling said fluid material to said flowing liquid, a servo-positioning means coupled to said metering valve, a feedback signal means coupled to said positioning means, a comparator means having input means connected to said meter means and said feedback signal means and to a preset signal means and establishing a drive signal proportional to said flow related signal and said feedback signal, means connecting said comparator means to energize said positioning means in accordance with the drive signal to accurately position said linear metering valve in accordance with said drive signal, and said fluid material is an additive liquid, and having a tank containing said additive liquid, a gas pressure line connected to said tank, a housing enclosing said means to meter the flowing liquid, said metering valve, said feedback signal means, said servo-positioning means and said comparator means, means releasably securing said tank to the housing, and conduit means connecting said tank to said metering valve.

Claim 17

The additive metering system of claim 9 having a sight glass means connected between said gas pressure line and said conduit means to provide a visual indication of the additive liquid in said tank.