Method and apparatus for providing a determined ratio of process fluids

• US 20020179148A1
• Filed: 05/23/2002
• Published: 12/05/2002
• Est. Priority Date: 05/24/2001
• Status: Active Grant

• Current Assignee: Brooks Instrument LLC (Illinois Tool Works Inc.)
• Original Assignee: Celerity Incorporated (ICHOR Holdings, Ltd.)
• Inventors: Valentine, William S., Lull, John M.
• Granted Patent: US 6,752,166 B2
• Time in Patent Office: Days
• US Class Current: 137/487.5
• CPC Class Codes: G05D 11/132 by controlling the flow of the individual components G05D11/133 takes precedence
• CPC Class Codes: G05D 7/0664 the plurality of throttling means being arranged for the control of a plurality of diverging flows from a single flow G05D7/0652 takes precedence; ratio control G05D11/13
• CPC Class Codes: Y10T 137/0324 With control of flow by a condition or characteristic of a fluid
• CPC Class Codes: Y10T 137/0363 For producing proportionate flow
• CPC Class Codes: Y10T 137/0379 By fluid pressure
• CPC Class Codes: Y10T 137/0396 Involving pressure control
• CPC Class Codes: Y10T 137/7759 Responsive to change in rate of fluid flow
• CPC Class Codes: Y10T 137/7761 Electrically actuated valve
• CPC Class Codes: Y10T 137/87249 Multiple inlet with multiple outlet
• CPC Class Codes: Y10T 137/87877 Single inlet with multiple distinctly valved outlets

Abstract

A fluid flow control system that includes a fluid inlet to receive a flow of process fluid and a plurality of fluid outlets. The plurality of fluid outlets include a first fluid outlet and at least one second fluid outlet. The first fluid outlet provides a first predetermined portion of the flow of process fluid, and the at least one second fluid outlet provides the remaining portion of the flow of process fluid. In one embodiment. the control system includes a pressure transducer, first and second multipliers, and first and second flow controllers. The first multiplier multiplies a pressure signal received from the pressure transducer by a first setpoint to control a first flow controller that provides the first predetermined portion of the flow of process fluid. The second multiplier multiplies the pressure signal by a second setpoint to control a second flow controller that provides the remaining portion.

Claims

1. A fluid flow control system, comprising:

a fluid inlet to receive a flow of process fluid; and

a plurality of fluid outlets, the plurality of fluid outlets including a first fluid outlet and at least one second fluid outlet, the first fluid outlet providing a first predetermined portion of the flow of process fluid, and the at least one second fluid outlet providing a remaining portion of the flow of process fluid.

2. The fluid flow control system of claim 1, further comprising:

a pressure transducer, to measure a pressure of the process fluid in the fluid inlet and provide a pressure signal indicative of the pressure of the process fluid;

a first flow controller, fluidly coupled to the fluid inlet and the first fluid outlet, to receive a first setpoint indicative of the first predetermined portion of the flow of process fluid to be provided by the first fluid outlet; and

a pressure controller, fluidly coupled to the fluid inlet and the at least one second fluid outlet, to receive the pressure signal and a pressure setpoint indicative of a desired pressure of the process fluid in the fluid inlet, and to provide the remaining portion of the flow of process fluid to the at least one second fluid outlet.

3. The fluid flow control system of claim 2, further comprising:

a plurality of fluid supply flow controllers each having a fluid inlet and a fluid outlet, the fluid inlet of each respective fluid supply flow controller being fluidly coupled to a respective supply of fluid, each respective fluid supply flow controller receiving a respective setpoint indicative of an amount of the respective fluid to be provided at the fluid outlet of the respective fluid supply controller, and the fluid output of each respective fluid supply controller being fluidly coupled to the fluid inlet to provide the flow of process fluid;

a process controller, to provide the respective setpoint to each respective fluid supply controller, to provide the first setpoint to the first flow controller, and to provide the pressure setpoint to the pressure controller;

wherein the first setpoint provided to the first flow controller is based upon a fraction indicative of the first predetermined portion of the flow of process fluid that is to be provided by the first flow controller, multiplied by a sum, for the plurality of fluid supply controllers, of the respective setpoint provided to each respective fluid supply controller multiplied by a calibration factor corresponding to the respective fluid supply controller.

4. The fluid flow control system of claim 3, wherein the calibration factor for a respective fluid supply controller is equal to a full scale range of the respective fluid supply controller on a known fluid divided by a full scale range of the first flow controller on the known fluid.

5. The fluid flow control system of claim 4, wherein the known fluid is nitrogen.

6. The fluid flow control system of claim 4, wherein the plurality of fluid supply flow controllers and the first flow controller are mass flow controllers.

7. The fluid flow control system of claim 4, wherein the first flow controller is a mass flow controller that includes a valve and a flow sensor, and wherein the flow sensor is disposed downstream of the valve.

8. The fluid control system of claim 1, further comprising:

a pressure transducer, to measure a pressure of the process fluid in the fluid inlet and provide a pressure signal indicative of the pressure of the process fluid;

a feedback controller to receive the pressure signal and a pressure setpoint indicative of a desired pressure of the process fluid in the fluid inlet, and to provide a first setpoint indicative of the flow of process fluid;

a first multiplier to receive the first setpoint and a second setpoint indicative of the first predetermined portion of the flow of process fluid to be provided by the first fluid outlet and multiply the first setpoint by the second setpoint to provide a first multiplied setpoint;

a first flow controller, fluidly coupled to the fluid inlet and the first fluid outlet, to receive the first multiplied setpoint and provide the first predetermined portion of the flow of process fluid to the first fluid outlet based upon the first multiplied setpoint;

a second multiplier to receive the first setpoint and a third setpoint indicative of the remaining portion of the flow of process fluid to be provided by the at least one second fluid outlet and multiply the first setpoint by the third setpoint to provide a second multiplied setpoint; and

a second flow controller, fluidly coupled to the fluid inlet and the at least one second fluid outlet, to receive the second multiplied setpoint and provide the remaining portion of the flow of process fluid to the at least one second fluid outlet based upon the second multiplied setpoint.

9. The fluid flow control system of claim 8, wherein the feedback controller is a proportional, integral, differential feedback controller.

10. The fluid flow controller of claim 8, further comprising:

a subtraction circuit to receive the second setpoint and subtract the second setpoint from a value indicative of a full-scale flow of process fluid to provide the third setpoint to the second multiplier.

11. The fluid flow control system of claim 10, further comprising:

a plurality of fluid supply flow controllers each having a fluid inlet and a fluid outlet, the fluid inlet of each respective fluid supply flow controller being fluidly coupled to a respective supply of fluid, each respective fluid supply flow controller receiving a respective setpoint indicative of an amount of the respective fluid to be provided at the fluid outlet of the respective fluid supply controller, and the fluid output of each respective fluid supply controller being fluidly coupled to the fluid inlet to provide the flow of process fluid; and

a process controller, to provide the respective setpoint to each respective fluid supply controller, to provide the pressure setpoint to the feedback controller, and to provide the second setpoint to the first multiplier.

12. The fluid flow control system of claim 11, wherein the plurality of fluid supply flow controllers and the first and second flow controllers are mass flow controllers.

13. The fluid flow control system of claim 12, wherein the first and second flow controllers are mass flow controllers that include a valve and a flow sensor, and wherein the flow sensor is disposed downstream of the valve in each of the first and second flow controllers.

14. The fluid flow control system of claim 13, wherein the first and second flow controllers are tuned to have a similar response on a known fluid.

15. The fluid flow control system of claim 8, further comprising:

a plurality of fluid supply flow controllers each having a fluid inlet and a fluid outlet, the fluid inlet of each respective fluid supply flow controller being fluidly coupled to a respective supply of fluid, each respective fluid supply flow controller receiving a respective setpoint indicative of an amount of the respective fluid to be provided at the fluid outlet of the respective fluid supply controller, and the fluid output of each respective fluid supply controller being fluidly coupled to the fluid inlet to provide the flow of process fluid; and

a process controller, to provide the respective setpoint to each respective fluid supply controller, to provide the pressure setpoint to the feedback controller, and to provide the second setpoint to the first multiplier.

16. The fluid flow control system of claim 15, wherein the plurality of fluid supply flow controllers and the first and second flow controllers are mass flow controllers, wherein the first and second flow controllers include a valve and a flow sensor, and wherein the flow sensor is disposed downstream of the valve in each of the first and second flow controllers.

17. The fluid flow control system of claim 16, wherein the first and second flow controllers are tuned to have a similar response on a known fluid.

18. The fluid control system of claim 1, further comprising:

a pressure transducer, to measure a pressure of the process fluid in the fluid inlet and provide a pressure signal indicative of the pressure of the process fluid;

a first multiplier to receive the pressure signal and a first setpoint indicative of the first predetermined portion of the flow of process fluid to be provided by the first fluid outlet and multiply the pressure signal by the first setpoint to provide a first multiplied setpoint;

a first flow controller, fluidly coupled to the fluid inlet and the first fluid outlet, to receive the first multiplied setpoint and provide the first predetermined portion of the flow of process fluid to the first fluid outlet based upon the first multiplied setpoint;

a second multiplier to receive the pressure signal and a second setpoint indicative of the remaining portion of the flow of process fluid to be provided by the at least one second fluid outlet and multiply the pressure signal by the second setpoint to provide a second multiplied setpoint; and

a second flow controller, fluidly coupled to the fluid inlet and the at least one second fluid outlet, to receive the second multiplied setpoint and provide the remaining portion of the flow of process fluid to the at least one second fluid outlet based upon the second multiplied setpoint.

19. The fluid flow controller of claim 18, further comprising:

a subtraction circuit to receive the first setpoint, subtract the first setpoint from a value indicative of a full-scale flow of process fluid to provide the second setpoint to the second multiplier.

20. The fluid flow control system of claim 18, further comprising:

a plurality of fluid supply flow controllers each having a fluid inlet and a fluid outlet, the fluid inlet of each respective fluid supply flow controller being fluidly coupled to a respective supply of fluid, each respective fluid supply flow controller receiving a respective setpoint indicative of an amount of the respective fluid to be provided at the fluid outlet of the respective fluid supply controller, and the fluid output of each respective fluid supply controller being fluidly coupled to the fluid inlet to provide the flow of process fluid; and

a process controller, to provide the respective setpoint to each respective fluid supply controller, and to provide the first and second setpoints to the first and second multipliers, respectively.

21. The fluid flow control system of claim 20, wherein the first and second flow controllers are tuned to have a similar response on a known fluid.

22. The fluid flow control system of claim 1, wherein the at least one second fluid outlet includes a plurality of second fluid outlets that together provide the remaining portion of the flow of process fluid, the fluid flow control system further comprising:

a pressure transducer, to measure a pressure of the process fluid in the fluid inlet and provide a pressure signal indicative of the pressure of the process fluid;

a feedback controller to receive the pressure signal and a pressure setpoint indicative of a desired pressure of the process fluid in the fluid inlet, and to provide a first setpoint indicative of the flow of process fluid;

a first multiplier to receive the first setpoint and a second setpoint indicative of the first predetermined portion of the flow of process fluid to be provided by the first fluid outlet and multiply the first setpoint by the second setpoint to provide a first multiplied setpoint;

a first flow controller, fluidly coupled to the fluid inlet and the first fluid outlet, to receive the first multiplied setpoint and provide the first predetermined portion of the flow of process fluid to the first fluid outlet based upon the first multiplied setpoint;

a plurality of second multipliers, each corresponding to a respective second fluid outlet of the plurality of second fluid outlets, to receive the first setpoint and a respective third setpoint indicative of a respective second portion of the flow of process fluid to be provided by the respective second fluid outlet and multiply the first setpoint by the respective third setpoint to provide a respective second multiplied setpoint; and

a plurality of second flow controllers, fluidly coupled to the fluid inlet and a respective second fluid outlet, to receive a respective second multiplied setpoint and provide a respective second portion of the flow of process fluid based upon the second multiplied setpoint.

23. The fluid flow control system of claim 22, wherein the first flow controller and each of the plurality of second flow controllers are tuned to have a similar response on a known fluid.

24. The fluid flow control system of claim 1, wherein the at least one second fluid outlet includes a plurality of second fluid outlets that together provide the remaining portion of the flow of process fluid, the fluid flow control system further comprising:

a pressure transducer, to measure a pressure of the process fluid in the fluid inlet and provide a pressure signal indicative of the pressure of the process fluid;

a first multiplier to receive the pressure signal and a first setpoint indicative of the first predetermined portion of the flow of process fluid to be provided by the first fluid outlet and multiply the pressure by the first setpoint to provide a first multiplied setpoint;

a first flow controller, fluidly coupled to the fluid inlet and the first fluid outlet, to receive the first multiplied setpoint and provide the first predetermined portion of the flow of process fluid to the first fluid outlet based upon the first multiplied setpoint;

a plurality of second multipliers, each corresponding to a respective second fluid outlet of the plurality of second fluid outlets, to receive the pressure signal and a respective second setpoint indicative of a respective second portion of the flow of process fluid to be provided by the respective second fluid outlet and multiply the pressure signal by the respective second setpoint to provide a respective second multiplied setpoint; and

a plurality of second flow controllers, fluidly coupled to the fluid inlet and a respective second fluid outlet, to receive a respective second multiplied setpoint and provide a respective second portion of the flow of process fluid based upon the second multiplied setpoint.

25. The fluid flow control system of claim 24, wherein the first flow controller and the plurality of second flow controllers are tuned to have a similar response on a known fluid.

26. The fluid control system of claim 1, further comprising:

a pressure transducer, to measure a pressure of the process fluid in the fluid inlet and provide a pressure signal indicative of the pressure of the process fluid;

a pulse width modulated controller to receive the pressure signal, a pressure setpoint indicative of a desired pressure of the process fluid in the fluid inlet, and a first setpoint indicative of the first predetermined portion of the flow of process fluid to be provided by the first fluid outlet, the pulse width modulated controller providing first and second pulse width modulated control signals;

a first critical flow nozzle, fluidly coupled to the fluid inlet, to receive the flow of process fluid and reduce the pressure of the process fluid;

a second critical flow nozzle, fluidly coupled to the fluid inlet, to receive the flow of process fluid and reduce the pressure of the process fluid;

a first control valve, fluidly coupled to the first critical flow nozzle and the first fluid outlet, to receive the first pulse width modulated control signal and provide the first predetermined portion of the flow of process fluid to the first fluid outlet based upon the first pulse with modulated control signal; and

a second control valve, fluidly coupled to the second critical flow nozzle and the at least one second fluid outlet, to receive the second pulse width modulated control signal and provide the remaining portion of the flow of process fluid to the at least one second fluid outlet based upon the second pulse with modulated control signal.

27. The fluid flow control system of claim 26, wherein the first and second critical flow nozzles are substantially identical.

28. The fluid flow control system of claim 26, wherein the first and second critical flow nozzles reduce the pressure of the process fluid by approximately a two to one ratio.

29. The fluid flow control system of claim 26, wherein the first and second control valves are digital control valves.

30. The fluid flow control system of claim 26, wherein at least one of a frequency and a duration of the first and second pulse width modulated control signals is modulated based upon the pressure signal, the pressure setpoint, and the first setpoint.

31. The fluid flow control system of claim 30, wherein at least one of the frequency and the duration of one of the first and second pulse width modulated control signals is further modulated to make performance of the first and second critical flow nozzles substantially identical.

32. The fluid flow control system of claim 26, wherein:

the first and second critical flow nozzles reduce the pressure of the process fluid by a two to one ratio;

the first and second control valves are digital control valves;

at least one of a frequency and a duration of the first and second pulse width modulated control signals is modulated based upon the pressure signal, the pressure setpoint, and the first setpoint; and

wherein at least one of the frequency and the duration of one of the first and second pulse width modulated control signals is further modulated to make performance of the first and second critical flow nozzles substantially identical.

33. The fluid flow control system of claim 1, wherein the plurality of fluid outlets are fluidly connected to a semiconductor wafer processing chamber.

34. The fluid flow control system of claim 1, wherein the process fluid is a gaseous process fluid.

36. The method of claim 35, further comprising acts of:

receiving a first setpoint indicative of the first predetermined portion of the flow of process fluid to be provided to the first fluid outlet; and

directing a first flow controller to provide the first predetermined portion of the flow of process fluid to the first fluid outlet based upon the first setpoint.

37. The method of claim 36, further comprising acts of:

measuring a pressure of the process fluid in the fluid inlet; and

receiving a pressure setpoint indicative of a desired pressure of the process fluid in the fluid inlet;

wherein the act of providing the remaining portion of the flow of process fluid includes an act of providing an amount of process fluid to the at least one second fluid outlet to maintain the pressure of the process fluid at the pressure setpoint.

38. The method of claim 37, further comprising acts of:

receiving a plurality of respective setpoints indicative of a plurality of respective amounts of fluid to be respectively provided from a plurality of respective fluid supplies by a respective fluid supply flow controller;

combining the plurality of respective amounts of fluid to form the flow of process fluid; and

determining the first setpoint based upon a fraction indicative of the first predetermined portion of the flow of process fluid to be provided to the first fluid outlet multiplied by a sum, for the plurality of respective amounts of fluid, of each respective setpoint multiplied by a calibration factor corresponding to the respective fluid supply controller.

39. The method of claim 38, further comprising an act of:

determining the calibration factor for each respective fluid supply controller based upon a full scale range of the respective fluid supply controller on a known fluid divided by a full scale range of the first flow controller on the known fluid.

40. The method of claim 39, wherein the known fluid is nitrogen.

41. The method of claim 36, wherein the first flow controller includes a flow sensor and a valve, the method further comprising an act of:

minimizing affects of pressure transients on the flow sensor by disposing the flow sensor downstream of the valve.

42. The method of claim 35, further comprising acts of:

measuring a pressure of the process fluid in the fluid inlet;

receiving a pressure setpoint indicative of a desired pressure of the process fluid in the fluid inlet;

determining a first setpoint indicative of the flow of process fluid in the fluid inlet based upon the pressure setpoint and the pressure of the process fluid;

receiving a second setpoint indicative of the first predetermined portion of the flow of process fluid to be provided to the first fluid outlet;

multiplying the first setpoint by the second setpoint to determine a first multiplied setpoint; and

directing a first flow controller to provide the first predetermined portion of the flow of process fluid to the first fluid outlet based upon the first multiplied setpoint.

43. The method of claim 42, further comprising acts of:

multiplying the first setpoint by a third setpoint indicative of the remaining portion of the flow of process fluid to be provided to the at least one second fluid outlet to determine a second multiplied setpoint; and

directing a second flow controller to provide the remaining portion of the flow of process fluid to the at least one second fluid outlet based upon the second multiplied setpoint.

44. The method of claim 43, further comprising an act of:

tuning the first and second flow controllers to have a similar response on a known fluid.

45. The method of claim 43, further comprising acts of:

receiving a value indicative of the flow of process fluid received at the fluid inlet; and

determining the third setpoint by subtracting the second setpoint from the value indicative of a full-scale flow of process fluid received at the fluid inlet.

46. The method of claim 45, further comprising an act of:

tuning the first and second flow controllers to have a similar response on a known fluid.

47. The method of claim 46, wherein the first and second flow controllers each include a flow sensor and a valve, the method further comprising an act of:

minimizing affects of pressure transients on the flow sensor by disposing the flow sensor downstream of the valve in each of the first and second flow controllers.

48. The method of claim 35, further comprising acts of:

measuring a pressure of the process fluid in the fluid inlet;

receiving a first setpoint indicative of the first predetermined portion of the flow of process fluid to be provided to the first fluid outlet;

multiplying the first setpoint by the pressure of the process fluid to determine a first multiplied setpoint; and

directing a first flow controller to provide the first predetermined portion of the flow of process fluid to the first fluid outlet based upon the first multiplied setpoint.

49. The method of claim 48, further comprising acts of:

multiplying the pressure of the process fluid by a second setpoint indicative of the remaining portion of the flow of process fluid to be provided to the at least one second fluid outlet to determine a second multiplied setpoint; and

directing a second flow controller to provide the remaining portion of the flow of process fluid to the at least one second fluid outlet based upon the second multiplied setpoint.

50. The method of claim 49, further comprising an act of:

tuning the first and second flow controllers to have a similar response on a known fluid.

51. The method of claim 49, further comprising acts of:

receiving a value indicative of the flow of process fluid received at the fluid inlet; and

determining the second setpoint by subtracting the first setpoint from the value indicative of a full-scale flow of process fluid received at the fluid inlet.

52. The method of claim 51, further comprising an act of:

tuning the first and second flow controllers to have a similar response on a known fluid.

53. The method of claim 52, wherein the first and second flow controllers each include a flow sensor and a valve, the method further comprising an act of:

minimizing affects of pressure transients on the flow sensor by disposing the flow sensor downstream of the valve in each of the first and second flow controllers.

54. The method of claim 35, wherein the at least one second fluid outlet includes a plurality of second fluid outlets that together provide the remaining portion of the flow of process fluid, the method further comprising acts of:

measuring a pressure of the process fluid in the fluid inlet;

receiving a first setpoint indicative of the first predetermined portion of the flow of process fluid to be provided to the first fluid outlet;

multiplying the first setpoint by the pressure of the process fluid to determine a first multiplied setpoint;

directing a first flow controller to provide the first predetermined portion of the flow of process fluid to the first fluid outlet based upon the first multiplied setpoint;

receiving a plurality of second setpoints, each corresponding to a second fluid outlet of the plurality of second fluid outlets;

multiplying each respective second setpoint by the pressure of the process fluid to respectively determine a plurality of respective second multiplied setpoints; and

directing each of a plurality of second flow controllers that respectively correspond to a respective second fluid outlet of the plurality of second fluid outlets to provide a respective second portion of the flow of process fluid based upon each of the respective second multiplied setpoints.

55. The method of claim 54, further comprising an act of:

tuning the first flow controller and each of the plurality of second flow controllers to have a similar response on a known fluid.

56. The method of claim 35, further comprising acts of:

measuring a pressure of the process fluid in the fluid inlet;

receiving a pressure setpoint indicative of a desired pressure of the process fluid in the fluid inlet;

receiving a first setpoint indicative of the first portion of the flow of process fluid to be provided to the first fluid outlet;

generating a first pulse width modulated control signal based upon the pressure of the process fluid in the fluid inlet, the pressure setpoint, and the first setpoint; and

controlling a first valve to provide the first portion of the flow of process fluid to the first outlet based upon the first pulse width modulated control signal.

57. The method of claim 56, further comprising acts of:

generating a second pulse width modulated control signal based upon the pressure of the process fluid in the fluid inlet, the pressure setpoint, and the first setpoint; and

controlling a second valve to provide the remaining portion of the flow of process fluid to the at least one second fluid outlet based upon the second pulse width modulated control signal.

58. The method of claim 57, further comprising an act of:

reducing the pressure of the process fluid prior to providing the flow of process fluid to the first and second valves.

59. The method of claim 58, wherein the act of reducing the pressure includes an act of reducing the pressure of the process fluid by approximately a two to one ratio.

60. The method of claim 58, further comprising an act of:

modulating at least one of a frequency and a duration of the first and second pulse width modulated control signals based upon the pressure signal, the pressure setpoint, and the first setpoint.

61. The method of claim 60, wherein the act of reducing the pressure is performed by first and second critical flow nozzles respective disposed upstream of the first and second valves, and wherein the act of modulating further includes an act of further modulating at least one of the frequency and the duration of one of the first and second pulse width modulated control signals make performance of the first and second critical flow nozzles substantially identical.

73. The fluid flow control system of claim 1, wherein the at least one second fluid outlet comprises a single second fluid outlet, the fluid flow control system further comprising:

a valve having a fluid inlet fluidly coupled to the fluid inlet of the fluid flow control system, a first fluid outlet fluidly coupled to the first fluid outlet of the fluid control system, and a second fluid outlet fluidly coupled to the single second fluid outlet of the fluid control system, the valve respectively providing the first predetermined portion of the flow of process fluid and the remaining portion of the flow of process fluid to the first and second fluid outlets of the valve based upon a valve drive signal.

74. The fluid flow control system of claim 73, further comprising:

a controller to receive a setpoint indicative of the first predetermined portion of the flow of process fluid and a feedback signal indicative of a measured value of the first predetermined portion of the flow of process fluid and provide the valve drive signal.

75. The fluid flow control system of claim 74, further comprising:

a first flow meter to measure the first predetermined portion of the flow of process fluid provided by the first fluid outlet of the valve and provide a first flow signal;

a second flow meter to measure the remaining portion of the flow of process fluid provided by the second fluid outlet of the valve and provide a second flow signal;

an adder to receive and sum the first and second flow signals and provide a summed flow signal; and

a divider to receive the first flow signal and the summed flow signal, divide the first flow signal by the summed flow signal, and provide the divided signal to the controller as the feedback signal.

35. A method of controlling a flow of process fluid, comprising acts of:

receiving the flow of process fluid at a fluid inlet;

providing a first predetermined portion of the flow of process fluid to a first fluid outlet; and

providing a remaining portion of the flow of process fluid to at least one second fluid outlet.

62. A fluid flow controller to provide a flow of process fluid to a plurality of device inlets, comprising:

a fluid inlet to receive the flow of process fluid;

a plurality of fluid outlets to provide the flow of process fluid to the plurality of device inlets, the plurality of fluid outlets including a first fluid outlet and at least one additional fluid outlet;

a first input to receive a first signal indicative of an amount of the process fluid that is received at the fluid inlet; and

a second input to receive a second signal indicative of a first predetermined portion of the amount of the process fluid that is to be provided to the first fluid outlet, with a remaining portion of the amount of the process fluid being provided to the at least one additional fluid outlet.

63. The fluid flow controller of claim 62, further comprising:

a first multiplier, to receive the first signal and the second signal, multiply the first signal by the second signal to provide a first multiplied signal; and

a first flow controller, fluidly coupled to the fluid inlet and the first fluid outlet, to receive the first multiplied signal and provide the first predetermined portion of the amount of the process fluid to the first fluid outlet based upon the first multiplied signal.

64. The fluid flow controller of claim 63, wherein the first signal identifies a pressure of the process fluid received at the fluid inlet.

65. The fluid flow controller of claim 63, wherein the first signal is based upon a pressure of the process fluid received at the fluid inlet.

66. The fluid flow controller of claim 63, wherein the at least one additional fluid outlet includes a plurality of additional fluid outlets that together provide the remaining portion of the amount of the process fluid, the fluid flow controller further comprising:

a plurality of additional inputs each to receive a respective additional signal indicative of a respective second portion of the remaining portion of the amount of the process fluid to be respectively provided to each of the plurality of additional fluid outlets;

a plurality of second multipliers corresponding to each respective additional input, each to receive the first signal and the respective additional signal and multiply the first signal by the respective additional signal to provide a respective second multiplied signal; and

a plurality of second flow controllers corresponding to each respective second multiplier and fluidly coupled to the fluid inlet and a respective additional fluid outlet of the plurality of additional fluid outlets, each to receive the respective second multiplied signal from the corresponding second multiplier and provide the respective second portion of the remaining portion of the amount of process fluid to the respective additional fluid outlet based upon the respective second multiplied signal.

67. The fluid flow controller of claim 66, wherein the first signal identifies a pressure of the process fluid received at the fluid inlet.

68. The fluid flow controller of claim 66, wherein the first signal is based upon a pressure of the process fluid received at the fluid inlet.

70. The fluid flow controller of claim 69, further comprising:

a plurality of additional inputs each to receive a respective additional signal indicative of a second predetermined portion of the amount of the process fluid received at the fluid inlet; and

a plurality of second multipliers corresponding to each respective additional input, each to receive the first signal and the respective additional signal multiply the first signal by the respective additional signal, and provide a respective second multiplied signal indicative of each second predetermined portion of the amount of the process fluid, independent of the amount of the process fluid received at the fluid inlet.

71. The fluid flow controller of claim 69, wherein the first signal identifies a pressure of the process fluid received at the fluid inlet.

72. The fluid flow controller of claim 69, wherein the first signal is based upon a pressure of the process fluid received at the fluid inlet.

69. A fluid flow controller, comprising:

a first input to receive a first signal indicative of an amount of process fluid received at a fluid inlet;

a second input to receive a second signal indicative of a first predetermined portion of the received amount of the process fluid; and

a first multiplier, to receive the first signal and the second signal, multiply the first signal by the second signal, and provide a first multiplied signal indicative of the first predetermined portion of the amount of process fluid, independent of the amount of the process fluid received at the fluid inlet.